4 perl5db.pl - the perl debugger
8 perl -d your_Perl_script
12 C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
13 you invoke a script with C<perl -d>. This documentation tries to outline the
14 structure and services provided by C<perl5db.pl>, and to describe how you
19 The debugger can look pretty forbidding to many Perl programmers. There are
20 a number of reasons for this, many stemming out of the debugger's history.
22 When the debugger was first written, Perl didn't have a lot of its nicer
23 features - no references, no lexical variables, no closures, no object-oriented
24 programming. So a lot of the things one would normally have done using such
25 features was done using global variables, globs and the C<local()> operator
28 Some of these have survived into the current debugger; a few of the more
29 interesting and still-useful idioms are noted in this section, along with notes
30 on the comments themselves.
32 =head2 Why not use more lexicals?
34 Experienced Perl programmers will note that the debugger code tends to use
35 mostly package globals rather than lexically-scoped variables. This is done
36 to allow a significant amount of control of the debugger from outside the
39 Unfortunately, though the variables are accessible, they're not well
40 documented, so it's generally been a decision that hasn't made a lot of
41 difference to most users. Where appropriate, comments have been added to
42 make variables more accessible and usable, with the understanding that these
43 I<are> debugger internals, and are therefore subject to change. Future
44 development should probably attempt to replace the globals with a well-defined
45 API, but for now, the variables are what we've got.
47 =head2 Automated variable stacking via C<local()>
49 As you may recall from reading C<perlfunc>, the C<local()> operator makes a
50 temporary copy of a variable in the current scope. When the scope ends, the
51 old copy is restored. This is often used in the debugger to handle the
52 automatic stacking of variables during recursive calls:
57 # Do some stuff, then ...
61 What happens is that on entry to the subroutine, C<$some_global> is localized,
62 then altered. When the subroutine returns, Perl automatically undoes the
63 localization, restoring the previous value. Voila, automatic stack management.
65 The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
66 which lets the debugger get control inside of C<eval>'ed code. The debugger
67 localizes a saved copy of C<$@> inside the subroutine, which allows it to
68 keep C<$@> safe until it C<DB::eval> returns, at which point the previous
69 value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
70 track of C<$@> inside C<eval>s which C<eval> other C<eval's>.
72 In any case, watch for this pattern. It occurs fairly often.
76 This is used to cleverly reverse the sense of a logical test depending on
77 the value of an auxiliary variable. For instance, the debugger's C<S>
78 (search for subroutines by pattern) allows you to negate the pattern
81 # Find all non-'foo' subs:
84 Boolean algebra states that the truth table for XOR looks like this:
90 (! not present and no match) --> false, don't print
94 (! not present and matches) --> true, print
98 (! present and no match) --> true, print
102 (! present and matches) --> false, don't print
106 As you can see, the first pair applies when C<!> isn't supplied, and
107 the second pair applies when it is. The XOR simply allows us to
108 compact a more complicated if-then-elseif-else into a more elegant
109 (but perhaps overly clever) single test. After all, it needed this
112 =head2 FLAGS, FLAGS, FLAGS
114 There is a certain C programming legacy in the debugger. Some variables,
115 such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed
116 of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
117 of state to be stored independently in a single scalar.
123 is checking to see if the appropriate bit is on. Since each bit can be
124 "addressed" independently in this way, C<$scalar> is acting sort of like
125 an array of bits. Obviously, since the contents of C<$scalar> are just a
126 bit-pattern, we can save and restore it easily (it will just look like
129 The problem, is of course, that this tends to leave magic numbers scattered
130 all over your program whenever a bit is set, cleared, or checked. So why do
137 First, doing an arithmetical or bitwise operation on a scalar is
138 just about the fastest thing you can do in Perl: C<use constant> actually
139 creates a subroutine call, and array and hash lookups are much slower. Is
140 this over-optimization at the expense of readability? Possibly, but the
141 debugger accesses these variables a I<lot>. Any rewrite of the code will
142 probably have to benchmark alternate implementations and see which is the
143 best balance of readability and speed, and then document how it actually
148 Second, it's very easy to serialize a scalar number. This is done in
149 the restart code; the debugger state variables are saved in C<%ENV> and then
150 restored when the debugger is restarted. Having them be just numbers makes
155 Third, some of these variables are being shared with the Perl core
156 smack in the middle of the interpreter's execution loop. It's much faster for
157 a C program (like the interpreter) to check a bit in a scalar than to access
158 several different variables (or a Perl array).
162 =head2 What are those C<XXX> comments for?
164 Any comment containing C<XXX> means that the comment is either somewhat
165 speculative - it's not exactly clear what a given variable or chunk of
166 code is doing, or that it is incomplete - the basics may be clear, but the
167 subtleties are not completely documented.
169 Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
171 =head1 DATA STRUCTURES MAINTAINED BY CORE
173 There are a number of special data structures provided to the debugger by
174 the Perl interpreter.
176 The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline> via glob
177 assignment) contains the text from C<$filename>, with each element
178 corresponding to a single line of C<$filename>.
180 The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
181 assignment) contains breakpoints and actions. The keys are line numbers;
182 you can set individual values, but not the whole hash. The Perl interpreter
183 uses this hash to determine where breakpoints have been set. Any true value is
184 considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
185 Values are magical in numeric context: 1 if the line is breakable, 0 if not.
187 The scalar C<${"_<$filename"}> simply contains the string C<_<$filename>.
188 This is also the case for evaluated strings that contain subroutines, or
189 which are currently being executed. The $filename for C<eval>ed strings looks
190 like C<(eval 34)> or C<(re_eval 19)>.
192 =head1 DEBUGGER STARTUP
194 When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
195 non-interactive sessions, C<.perldb> for interactive ones) that can set a number
196 of options. In addition, this file may define a subroutine C<&afterinit>
197 that will be executed (in the debugger's context) after the debugger has
200 Next, it checks the C<PERLDB_OPTS> environment variable and treats its
201 contents as the argument of a C<o> command in the debugger.
203 =head2 STARTUP-ONLY OPTIONS
205 The following options can only be specified at startup.
206 To set them in your rcfile, add a call to
207 C<&parse_options("optionName=new_value")>.
213 the TTY to use for debugging i/o.
217 if set, goes in NonStop mode. On interrupt, if TTY is not set,
218 uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
219 Term::Rendezvous. Current variant is to have the name of TTY in this
224 if false, a dummy ReadLine is used, so you can debug
225 ReadLine applications.
229 if true, no i/o is performed until interrupt.
233 file or pipe to print line number info to. If it is a
234 pipe, a short "emacs like" message is used.
238 host:port to connect to on remote host for remote debugging.
242 file to store session history to. There is no default and so no
243 history file is written unless this variable is explicitly set.
247 number of commands to store to the file specified in C<HistFile>.
254 &parse_options("NonStop=1 LineInfo=db.out");
255 sub afterinit { $trace = 1; }
257 The script will run without human intervention, putting trace
258 information into C<db.out>. (If you interrupt it, you had better
259 reset C<LineInfo> to something I<interactive>!)
261 =head1 INTERNALS DESCRIPTION
263 =head2 DEBUGGER INTERFACE VARIABLES
265 Perl supplies the values for C<%sub>. It effectively inserts
266 a C<&DB::DB();> in front of each place that can have a
267 breakpoint. At each subroutine call, it calls C<&DB::sub> with
268 C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
269 {require 'perl5db.pl'}> before the first line.
271 After each C<require>d file is compiled, but before it is executed, a
272 call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
273 is the expanded name of the C<require>d file (as found via C<%INC>).
275 =head3 IMPORTANT INTERNAL VARIABLES
279 Used to control when the debugger will attempt to acquire another TTY to be
284 =item * 1 - on C<fork()>
286 =item * 2 - debugger is started inside debugger
288 =item * 4 - on startup
294 The value -2 indicates that no return value should be printed.
295 Any other positive value causes C<DB::sub> to print return values.
299 The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
300 contents of C<@_> when C<DB::eval> is called.
304 Determines what messages (if any) will get printed when a subroutine (or eval)
305 is entered or exited.
309 =item * 0 - No enter/exit messages
311 =item * 1 - Print I<entering> messages on subroutine entry
313 =item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
315 =item * 4 - Extended messages: C<< <in|out> I<context>=I<fully-qualified sub name> from I<file>:I<line> >>. If no other flag is on, acts like 1+4.
317 =item * 8 - Adds parameter information to messages, and overloaded stringify and tied FETCH is enabled on the printed arguments. Ignored if C<4> is not on.
319 =item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is is not on.
323 To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
324 The debugger internally juggles the value of C<$frame> during execution to
325 protect external modules that the debugger uses from getting traced.
329 Tracks current debugger nesting level. Used to figure out how many
330 C<E<lt>E<gt>> pairs to surround the line number with when the debugger
331 outputs a prompt. Also used to help determine if the program has finished
332 during command parsing.
334 =head4 C<$onetimeDump>
336 Controls what (if anything) C<DB::eval()> will print after evaluating an
341 =item * C<undef> - don't print anything
343 =item * C<dump> - use C<dumpvar.pl> to display the value returned
345 =item * C<methods> - print the methods callable on the first item returned
349 =head4 C<$onetimeDumpDepth>
351 Controls how far down C<dumpvar.pl> will go before printing C<...> while
352 dumping a structure. Numeric. If C<undef>, print all levels.
356 Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
357 which is called before every statement, checks this and puts the user into
358 command mode if it finds C<$signal> set to a true value.
362 Controls behavior during single-stepping. Stacked in C<@stack> on entry to
363 each subroutine; popped again at the end of each subroutine.
367 =item * 0 - run continuously.
369 =item * 1 - single-step, go into subs. The C<s> command.
371 =item * 2 - single-step, don't go into subs. The C<n> command.
373 =item * 4 - print current sub depth (turned on to force this when C<too much
380 Controls the output of trace information.
384 =item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
386 =item * 2 - watch expressions are active
388 =item * 4 - user defined a C<watchfunction()> in C<afterinit()>
392 =head4 C<$slave_editor>
394 1 if C<LINEINFO> was directed to a pipe; 0 otherwise.
398 Stack of filehandles that C<DB::readline()> will read commands from.
399 Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
403 Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
404 supplied by the Perl interpreter to the debugger. Contains the source.
408 Previous values of watch expressions. First set when the expression is
409 entered; reset whenever the watch expression changes.
413 Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
414 so that the debugger can substitute safe values while it's running, and
415 restore them when it returns control.
419 Saves the current value of C<$single> on entry to a subroutine.
420 Manipulated by the C<c> command to turn off tracing in all subs above the
425 The 'watch' expressions: to be evaluated before each line is executed.
429 The typeahead buffer, used by C<DB::readline>.
433 Command aliases. Stored as character strings to be substituted for a command
436 =head4 C<%break_on_load>
438 Keys are file names, values are 1 (break when this file is loaded) or undef
439 (don't break when it is loaded).
443 Keys are line numbers, values are C<condition\0action>. If used in numeric
444 context, values are 0 if not breakable, 1 if breakable, no matter what is
445 in the actual hash entry.
447 =head4 C<%had_breakpoints>
449 Keys are file names; values are bitfields:
453 =item * 1 - file has a breakpoint in it.
455 =item * 2 - file has an action in it.
459 A zero or undefined value means this file has neither.
463 Stores the debugger options. These are character string values.
467 Saves breakpoints for code that hasn't been compiled yet.
468 Keys are subroutine names, values are:
472 =item * C<compile> - break when this sub is compiled
474 =item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
478 =head4 C<%postponed_file>
480 This hash keeps track of breakpoints that need to be set for files that have
481 not yet been compiled. Keys are filenames; values are references to hashes.
482 Each of these hashes is keyed by line number, and its values are breakpoint
483 definitions (C<condition\0action>).
485 =head1 DEBUGGER INITIALIZATION
487 The debugger's initialization actually jumps all over the place inside this
488 package. This is because there are several BEGIN blocks (which of course
489 execute immediately) spread through the code. Why is that?
491 The debugger needs to be able to change some things and set some things up
492 before the debugger code is compiled; most notably, the C<$deep> variable that
493 C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
494 debugger has to turn off warnings while the debugger code is compiled, but then
495 restore them to their original setting before the program being debugged begins
498 The first C<BEGIN> block simply turns off warnings by saving the current
499 setting of C<$^W> and then setting it to zero. The second one initializes
500 the debugger variables that are needed before the debugger begins executing.
501 The third one puts C<$^X> back to its former value.
503 We'll detail the second C<BEGIN> block later; just remember that if you need
504 to initialize something before the debugger starts really executing, that's
511 BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
513 # Debugger for Perl 5.00x; perl5db.pl patch level:
516 $header = "perl5db.pl version $VERSION";
518 =head1 DEBUGGER ROUTINES
522 This function replaces straight C<eval()> inside the debugger; it simplifies
523 the process of evaluating code in the user's context.
525 The code to be evaluated is passed via the package global variable
526 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
528 Before we do the C<eval()>, we preserve the current settings of C<$trace>,
529 C<$single>, C<$^D> and C<$usercontext>. The latter contains the
530 preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
531 user's current package, grabbed when C<DB::DB> got control. This causes the
532 proper context to be used when the eval is actually done. Afterward, we
533 restore C<$trace>, C<$single>, and C<$^D>.
535 Next we need to handle C<$@> without getting confused. We save C<$@> in a
536 local lexical, localize C<$saved[0]> (which is where C<save()> will put
537 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
538 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
539 considered sane by the debugger. If there was an C<eval()> error, we print
540 it on the debugger's output. If C<$onetimedump> is defined, we call
541 C<dumpit> if it's set to 'dump', or C<methods> if it's set to
542 'methods'. Setting it to something else causes the debugger to do the eval
543 but not print the result - handy if you want to do something else with it
544 (the "watch expressions" code does this to get the value of the watch
545 expression but not show it unless it matters).
547 In any case, we then return the list of output from C<eval> to the caller,
548 and unwinding restores the former version of C<$@> in C<@saved> as well
549 (the localization of C<$saved[0]> goes away at the end of this scope).
551 =head3 Parameters and variables influencing execution of DB::eval()
553 C<DB::eval> isn't parameterized in the standard way; this is to keep the
554 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
555 The variables listed below influence C<DB::eval()>'s execution directly.
559 =item C<$evalarg> - the thing to actually be eval'ed
561 =item C<$trace> - Current state of execution tracing
563 =item C<$single> - Current state of single-stepping
565 =item C<$onetimeDump> - what is to be displayed after the evaluation
567 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
571 The following variables are altered by C<DB::eval()> during its execution. They
572 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
576 =item C<@res> - used to capture output from actual C<eval>.
578 =item C<$otrace> - saved value of C<$trace>.
580 =item C<$osingle> - saved value of C<$single>.
582 =item C<$od> - saved value of C<$^D>.
584 =item C<$saved[0]> - saved value of C<$@>.
586 =item $\ - for output of C<$@> if there is an evaluation error.
590 =head3 The problem of lexicals
592 The context of C<DB::eval()> presents us with some problems. Obviously,
593 we want to be 'sandboxed' away from the debugger's internals when we do
594 the eval, but we need some way to control how punctuation variables and
595 debugger globals are used.
597 We can't use local, because the code inside C<DB::eval> can see localized
598 variables; and we can't use C<my> either for the same reason. The code
599 in this routine compromises and uses C<my>.
601 After this routine is over, we don't have user code executing in the debugger's
602 context, so we can use C<my> freely.
606 ############################################## Begin lexical danger zone
608 # 'my' variables used here could leak into (that is, be visible in)
609 # the context that the code being evaluated is executing in. This means that
610 # the code could modify the debugger's variables.
612 # Fiddling with the debugger's context could be Bad. We insulate things as
617 # 'my' would make it visible from user code
618 # but so does local! --tchrist
619 # Remember: this localizes @DB::res, not @main::res.
623 # Try to keep the user code from messing with us. Save these so that
624 # even if the eval'ed code changes them, we can put them back again.
625 # Needed because the user could refer directly to the debugger's
626 # package globals (and any 'my' variables in this containing scope)
627 # inside the eval(), and we want to try to stay safe.
628 local $otrace = $trace;
629 local $osingle = $single;
632 # Untaint the incoming eval() argument.
633 { ($evalarg) = $evalarg =~ /(.*)/s; }
635 # $usercontext built in DB::DB near the comment
636 # "set up the context for DB::eval ..."
637 # Evaluate and save any results.
638 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
640 # Restore those old values.
646 # Save the current value of $@, and preserve it in the debugger's copy
647 # of the saved precious globals.
650 # Since we're only saving $@, we only have to localize the array element
651 # that it will be stored in.
652 local $saved[0]; # Preserve the old value of $@
655 # Now see whether we need to report an error back to the user.
661 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
662 # are package globals.
663 elsif ($onetimeDump) {
664 if ( $onetimeDump eq 'dump' ) {
665 local $option{dumpDepth} = $onetimedumpDepth
666 if defined $onetimedumpDepth;
667 dumpit( $OUT, \@res );
669 elsif ( $onetimeDump eq 'methods' ) {
672 } ## end elsif ($onetimeDump)
676 ############################################## End lexical danger zone
678 # After this point it is safe to introduce lexicals.
679 # The code being debugged will be executing in its own context, and
680 # can't see the inside of the debugger.
682 # However, one should not overdo it: leave as much control from outside as
683 # possible. If you make something a lexical, it's not going to be addressable
684 # from outside the debugger even if you know its name.
686 # This file is automatically included if you do perl -d.
687 # It's probably not useful to include this yourself.
689 # Before venturing further into these twisty passages, it is
690 # wise to read the perldebguts man page or risk the ire of dragons.
692 # (It should be noted that perldebguts will tell you a lot about
693 # the underlying mechanics of how the debugger interfaces into the
694 # Perl interpreter, but not a lot about the debugger itself. The new
695 # comments in this code try to address this problem.)
697 # Note that no subroutine call is possible until &DB::sub is defined
698 # (for subroutines defined outside of the package DB). In fact the same is
699 # true if $deep is not defined.
701 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
703 # modified Perl debugger, to be run from Emacs in perldb-mode
704 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
705 # Johan Vromans -- upgrade to 4.0 pl 10
706 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
708 # (We have made efforts to clarify the comments in the change log
709 # in other places; some of them may seem somewhat obscure as they
710 # were originally written, and explaining them away from the code
711 # in question seems conterproductive.. -JM)
713 ########################################################################
715 # + A lot of things changed after 0.94. First of all, core now informs
716 # debugger about entry into XSUBs, overloaded operators, tied operations,
717 # BEGIN and END. Handy with `O f=2'.
718 # + This can make debugger a little bit too verbose, please be patient
719 # and report your problems promptly.
720 # + Now the option frame has 3 values: 0,1,2. XXX Document!
721 # + Note that if DESTROY returns a reference to the object (or object),
722 # the deletion of data may be postponed until the next function call,
723 # due to the need to examine the return value.
726 # + `v' command shows versions.
729 # + `v' command shows version of readline.
730 # primitive completion works (dynamic variables, subs for `b' and `l',
731 # options). Can `p %var'
732 # + Better help (`h <' now works). New commands <<, >>, {, {{.
733 # {dump|print}_trace() coded (to be able to do it from <<cmd).
734 # + `c sub' documented.
735 # + At last enough magic combined to stop after the end of debuggee.
736 # + !! should work now (thanks to Emacs bracket matching an extra
737 # `]' in a regexp is caught).
738 # + `L', `D' and `A' span files now (as documented).
739 # + Breakpoints in `require'd code are possible (used in `R').
740 # + Some additional words on internal work of debugger.
741 # + `b load filename' implemented.
742 # + `b postpone subr' implemented.
743 # + now only `q' exits debugger (overwritable on $inhibit_exit).
744 # + When restarting debugger breakpoints/actions persist.
745 # + Buglet: When restarting debugger only one breakpoint/action per
746 # autoloaded function persists.
748 # Changes: 0.97: NonStop will not stop in at_exit().
749 # + Option AutoTrace implemented.
750 # + Trace printed differently if frames are printed too.
751 # + new `inhibitExit' option.
752 # + printing of a very long statement interruptible.
753 # Changes: 0.98: New command `m' for printing possible methods
754 # + 'l -' is a synonym for `-'.
755 # + Cosmetic bugs in printing stack trace.
756 # + `frame' & 8 to print "expanded args" in stack trace.
757 # + Can list/break in imported subs.
758 # + new `maxTraceLen' option.
759 # + frame & 4 and frame & 8 granted.
761 # + nonstoppable lines do not have `:' near the line number.
762 # + `b compile subname' implemented.
763 # + Will not use $` any more.
764 # + `-' behaves sane now.
765 # Changes: 0.99: Completion for `f', `m'.
766 # + `m' will remove duplicate names instead of duplicate functions.
767 # + `b load' strips trailing whitespace.
768 # completion ignores leading `|'; takes into account current package
769 # when completing a subroutine name (same for `l').
770 # Changes: 1.07: Many fixed by tchrist 13-March-2000
772 # + Added bare minimal security checks on perldb rc files, plus
773 # comments on what else is needed.
774 # + Fixed the ornaments that made "|h" completely unusable.
775 # They are not used in print_help if they will hurt. Strip pod
776 # if we're paging to less.
777 # + Fixed mis-formatting of help messages caused by ornaments
778 # to restore Larry's original formatting.
779 # + Fixed many other formatting errors. The code is still suboptimal,
780 # and needs a lot of work at restructuring. It's also misindented
782 # + Fixed bug where trying to look at an option like your pager
784 # + Fixed some $? processing. Note: if you use csh or tcsh, you will
785 # lose. You should consider shell escapes not using their shell,
786 # or else not caring about detailed status. This should really be
787 # unified into one place, too.
788 # + Fixed bug where invisible trailing whitespace on commands hoses you,
789 # tricking Perl into thinking you weren't calling a debugger command!
790 # + Fixed bug where leading whitespace on commands hoses you. (One
791 # suggests a leading semicolon or any other irrelevant non-whitespace
792 # to indicate literal Perl code.)
793 # + Fixed bugs that ate warnings due to wrong selected handle.
794 # + Fixed a precedence bug on signal stuff.
795 # + Fixed some unseemly wording.
796 # + Fixed bug in help command trying to call perl method code.
797 # + Fixed to call dumpvar from exception handler. SIGPIPE killed us.
799 # + Added some comments. This code is still nasty spaghetti.
800 # + Added message if you clear your pre/post command stacks which was
801 # very easy to do if you just typed a bare >, <, or {. (A command
802 # without an argument should *never* be a destructive action; this
803 # API is fundamentally screwed up; likewise option setting, which
804 # is equally buggered.)
805 # + Added command stack dump on argument of "?" for >, <, or {.
806 # + Added a semi-built-in doc viewer command that calls man with the
807 # proper %Config::Config path (and thus gets caching, man -k, etc),
808 # or else perldoc on obstreperous platforms.
809 # + Added to and rearranged the help information.
810 # + Detected apparent misuse of { ... } to declare a block; this used
811 # to work but now is a command, and mysteriously gave no complaint.
813 # Changes: 1.08: Apr 25, 2001 Jon Eveland <jweveland@yahoo.com>
815 # + This patch to perl5db.pl cleans up formatting issues on the help
816 # summary (h h) screen in the debugger. Mostly columnar alignment
817 # issues, plus converted the printed text to use all spaces, since
818 # tabs don't seem to help much here.
820 # Changes: 1.09: May 19, 2001 Ilya Zakharevich <ilya@math.ohio-state.edu>
821 # Minor bugs corrected;
822 # + Support for auto-creation of new TTY window on startup, either
823 # unconditionally, or if started as a kid of another debugger session;
824 # + New `O'ption CreateTTY
825 # I<CreateTTY> bits control attempts to create a new TTY on events:
827 # 2: debugger is started inside debugger
829 # + Code to auto-create a new TTY window on OS/2 (currently one
830 # extra window per session - need named pipes to have more...);
831 # + Simplified interface for custom createTTY functions (with a backward
832 # compatibility hack); now returns the TTY name to use; return of ''
833 # means that the function reset the I/O handles itself;
834 # + Better message on the semantic of custom createTTY function;
835 # + Convert the existing code to create a TTY into a custom createTTY
837 # + Consistent support for TTY names of the form "TTYin,TTYout";
838 # + Switch line-tracing output too to the created TTY window;
839 # + make `b fork' DWIM with CORE::GLOBAL::fork;
840 # + High-level debugger API cmd_*():
841 # cmd_b_load($filenamepart) # b load filenamepart
842 # cmd_b_line($lineno [, $cond]) # b lineno [cond]
843 # cmd_b_sub($sub [, $cond]) # b sub [cond]
844 # cmd_stop() # Control-C
845 # cmd_d($lineno) # d lineno (B)
846 # The cmd_*() API returns FALSE on failure; in this case it outputs
847 # the error message to the debugging output.
848 # + Low-level debugger API
849 # break_on_load($filename) # b load filename
850 # @files = report_break_on_load() # List files with load-breakpoints
851 # breakable_line_in_filename($name, $from [, $to])
852 # # First breakable line in the
853 # # range $from .. $to. $to defaults
854 # # to $from, and may be less than
856 # breakable_line($from [, $to]) # Same for the current file
857 # break_on_filename_line($name, $lineno [, $cond])
858 # # Set breakpoint,$cond defaults to
860 # break_on_filename_line_range($name, $from, $to [, $cond])
861 # # As above, on the first
862 # # breakable line in range
863 # break_on_line($lineno [, $cond]) # As above, in the current file
864 # break_subroutine($sub [, $cond]) # break on the first breakable line
865 # ($name, $from, $to) = subroutine_filename_lines($sub)
866 # # The range of lines of the text
867 # The low-level API returns TRUE on success, and die()s on failure.
869 # Changes: 1.10: May 23, 2001 Daniel Lewart <d-lewart@uiuc.edu>
871 # + Fixed warnings generated by "perl -dWe 42"
872 # + Corrected spelling errors
873 # + Squeezed Help (h) output into 80 columns
875 # Changes: 1.11: May 24, 2001 David Dyck <dcd@tc.fluke.com>
876 # + Made "x @INC" work like it used to
878 # Changes: 1.12: May 24, 2001 Daniel Lewart <d-lewart@uiuc.edu>
879 # + Fixed warnings generated by "O" (Show debugger options)
880 # + Fixed warnings generated by "p 42" (Print expression)
881 # Changes: 1.13: Jun 19, 2001 Scott.L.Miller@compaq.com
882 # + Added windowSize option
883 # Changes: 1.14: Oct 9, 2001 multiple
884 # + Clean up after itself on VMS (Charles Lane in 12385)
885 # + Adding "@ file" syntax (Peter Scott in 12014)
886 # + Debug reloading selfloaded stuff (Ilya Zakharevich in 11457)
887 # + $^S and other debugger fixes (Ilya Zakharevich in 11120)
888 # + Forgot a my() declaration (Ilya Zakharevich in 11085)
889 # Changes: 1.15: Nov 6, 2001 Michael G Schwern <schwern@pobox.com>
890 # + Updated 1.14 change log
891 # + Added *dbline explainatory comments
892 # + Mentioning perldebguts man page
893 # Changes: 1.16: Feb 15, 2002 Mark-Jason Dominus <mjd@plover.com>
894 # + $onetimeDump improvements
895 # Changes: 1.17: Feb 20, 2002 Richard Foley <richard.foley@rfi.net>
896 # Moved some code to cmd_[.]()'s for clarity and ease of handling,
897 # rationalised the following commands and added cmd_wrapper() to
898 # enable switching between old and frighteningly consistent new
899 # behaviours for diehards: 'o CommandSet=pre580' (sigh...)
900 # a(add), A(del) # action expr (added del by line)
901 # + b(add), B(del) # break [line] (was b,D)
902 # + w(add), W(del) # watch expr (was W,W)
903 # # added del by expr
904 # + h(summary), h h(long) # help (hh) (was h h,h)
905 # + m(methods), M(modules) # ... (was m,v)
906 # + o(option) # lc (was O)
907 # + v(view code), V(view Variables) # ... (was w,V)
908 # Changes: 1.18: Mar 17, 2002 Richard Foley <richard.foley@rfi.net>
909 # + fixed missing cmd_O bug
910 # Changes: 1.19: Mar 29, 2002 Spider Boardman
911 # + Added missing local()s -- DB::DB is called recursively.
912 # Changes: 1.20: Feb 17, 2003 Richard Foley <richard.foley@rfi.net>
913 # + pre'n'post commands no longer trashed with no args
914 # + watch val joined out of eval()
915 # Changes: 1.21: Jun 04, 2003 Joe McMahon <mcmahon@ibiblio.org>
916 # + Added comments and reformatted source. No bug fixes/enhancements.
917 # + Includes cleanup by Robin Barker and Jarkko Hietaniemi.
918 # Changes: 1.22 Jun 09, 2003 Alex Vandiver <alexmv@MIT.EDU>
919 # + Flush stdout/stderr before the debugger prompt is printed.
920 # Changes: 1.23: Dec 21, 2003 Dominique Quatravaux
921 # + Fix a side-effect of bug #24674 in the perl debugger ("odd taint bug")
922 # Changes: 1.24: Mar 03, 2004 Richard Foley <richard.foley@rfi.net>
923 # + Added command to save all debugger commands for sourcing later.
924 # + Added command to display parent inheritance tree of given class.
925 # + Fixed minor newline in history bug.
926 # Changes: 1.25: Apr 17, 2004 Richard Foley <richard.foley@rfi.net>
927 # + Fixed option bug (setting invalid options + not recognising valid short forms)
928 # Changes: 1.26: Apr 22, 2004 Richard Foley <richard.foley@rfi.net>
929 # + unfork the 5.8.x and 5.9.x debuggers.
930 # + whitespace and assertions call cleanup across versions
931 # + H * deletes (resets) history
932 # + i now handles Class + blessed objects
933 # Changes: 1.27: May 09, 2004 Richard Foley <richard.foley@rfi.net>
934 # + updated pod page references - clunky.
935 # + removed windowid restriction for forking into an xterm.
936 # + more whitespace again.
937 # + wrapped restart and enabled rerun [-n] (go back n steps) command.
938 # Changes: 1.28: Oct 12, 2004 Richard Foley <richard.foley@rfi.net>
939 # + Added threads support (inc. e and E commands)
940 # Changes: 1.29: Nov 28, 2006 Bo Lindbergh <blgl@hagernas.com>
941 # + Added macosx_get_fork_TTY support
942 # Changes: 1.30: Mar 06, 2007 Andreas Koenig <andk@cpan.org>
943 # + Added HistFile, HistSize
945 # + Remove support for assertions and -A
946 # + stop NEXT::AUTOLOAD from emitting warnings under the debugger. RT #25053
947 # + "update for Mac OS X 10.5" [finding the tty device]
948 # + "What I needed to get the forked debugger to work" [on VMS]
949 # + [perl #57016] debugger: o warn=0 die=0 ignored
950 # + Note, but don't use, PERLDBf_SAVESRC
951 # + Fix #7013: lvalue subs not working inside debugger
952 ########################################################################
954 =head1 DEBUGGER INITIALIZATION
956 The debugger starts up in phases.
960 First, it initializes the environment it wants to run in: turning off
961 warnings during its own compilation, defining variables which it will need
962 to avoid warnings later, setting itself up to not exit when the program
963 terminates, and defaulting to printing return values for the C<r> command.
967 # Needed for the statement after exec():
969 # This BEGIN block is simply used to switch off warnings during debugger
970 # compiliation. Probably it would be better practice to fix the warnings,
971 # but this is how it's done at the moment.
976 } # Switch compilation warnings off until another BEGIN.
978 local ($^W) = 0; # Switch run-time warnings off during init.
980 =head2 THREADS SUPPORT
982 If we are running under a threaded Perl, we require threads and threads::shared
983 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
984 threaded debugger control. C<-dt> can also be used to set this.
986 Each new thread will be announced and the debugger prompt will always inform
987 you of each new thread created. It will also indicate the thread id in which
988 we are currently running within the prompt like this:
992 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
993 command prompt. The prompt will show: C<[0]> when running under threads, but
994 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
996 While running under threads, when you set or delete a breakpoint (etc.), this
997 will apply to all threads, not just the currently running one. When you are
998 in a currently executing thread, you will stay there until it completes. With
999 the current implementation it is not currently possible to hop from one thread
1002 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
1004 Note that threading support was built into the debugger as of Perl version
1005 C<5.8.6> and debugger version C<1.2.8>.
1010 # ensure we can share our non-threaded variables or no-op
1011 if ($ENV{PERL5DB_THREADED}) {
1013 require threads::shared;
1014 import threads::shared qw(share);
1018 print "Threads support enabled\n";
1025 # This would probably be better done with "use vars", but that wasn't around
1026 # when this code was originally written. (Neither was "use strict".) And on
1027 # the principle of not fiddling with something that was working, this was
1030 # These variables control the execution of 'dumpvar.pl'.
1031 $dumpvar::hashDepth,
1032 $dumpvar::arrayDepth,
1033 $dumpvar::dumpDBFiles,
1034 $dumpvar::dumpPackages,
1035 $dumpvar::quoteHighBit,
1036 $dumpvar::printUndef,
1037 $dumpvar::globPrint,
1038 $dumpvar::usageOnly,
1040 # used to save @ARGV and extract any debugger-related flags.
1043 # used to control die() reporting in diesignal()
1046 # used to prevent multiple entries to diesignal()
1047 # (if for instance diesignal() itself dies)
1050 # used to prevent the debugger from running nonstop
1056 foreach my $k (keys (%INC)) {
1057 &share(\$main::{'_<'.$filename});
1060 # Command-line + PERLLIB:
1061 # Save the contents of @INC before they are modified elsewhere.
1064 # This was an attempt to clear out the previous values of various
1065 # trapped errors. Apparently it didn't help. XXX More info needed!
1066 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
1068 # We set these variables to safe values. We don't want to blindly turn
1069 # off warnings, because other packages may still want them.
1070 $trace = $signal = $single = 0; # Uninitialized warning suppression
1071 # (local $^W cannot help - other packages!).
1073 # Default to not exiting when program finishes; print the return
1074 # value when the 'r' command is used to return from a subroutine.
1075 $inhibit_exit = $option{PrintRet} = 1;
1077 =head1 OPTION PROCESSING
1079 The debugger's options are actually spread out over the debugger itself and
1080 C<dumpvar.pl>; some of these are variables to be set, while others are
1081 subs to be called with a value. To try to make this a little easier to
1082 manage, the debugger uses a few data structures to define what options
1083 are legal and how they are to be processed.
1085 First, the C<@options> array defines the I<names> of all the options that
1091 CommandSet HistFile HistSize
1092 hashDepth arrayDepth dumpDepth
1093 DumpDBFiles DumpPackages DumpReused
1094 compactDump veryCompact quote
1095 HighBit undefPrint globPrint
1096 PrintRet UsageOnly frame
1098 ReadLine NonStop LineInfo
1099 maxTraceLen recallCommand ShellBang
1100 pager tkRunning ornaments
1101 signalLevel warnLevel dieLevel
1102 inhibit_exit ImmediateStop bareStringify
1103 CreateTTY RemotePort windowSize
1107 @RememberOnROptions = qw(DollarCaretP);
1111 Second, C<optionVars> lists the variables that each option uses to save its
1117 hashDepth => \$dumpvar::hashDepth,
1118 arrayDepth => \$dumpvar::arrayDepth,
1119 CommandSet => \$CommandSet,
1120 DumpDBFiles => \$dumpvar::dumpDBFiles,
1121 DumpPackages => \$dumpvar::dumpPackages,
1122 DumpReused => \$dumpvar::dumpReused,
1123 HighBit => \$dumpvar::quoteHighBit,
1124 undefPrint => \$dumpvar::printUndef,
1125 globPrint => \$dumpvar::globPrint,
1126 UsageOnly => \$dumpvar::usageOnly,
1127 CreateTTY => \$CreateTTY,
1128 bareStringify => \$dumpvar::bareStringify,
1130 AutoTrace => \$trace,
1131 inhibit_exit => \$inhibit_exit,
1132 maxTraceLen => \$maxtrace,
1133 ImmediateStop => \$ImmediateStop,
1134 RemotePort => \$remoteport,
1135 windowSize => \$window,
1136 HistFile => \$histfile,
1137 HistSize => \$histsize,
1142 Third, C<%optionAction> defines the subroutine to be called to process each
1148 compactDump => \&dumpvar::compactDump,
1149 veryCompact => \&dumpvar::veryCompact,
1150 quote => \&dumpvar::quote,
1153 ReadLine => \&ReadLine,
1154 NonStop => \&NonStop,
1155 LineInfo => \&LineInfo,
1156 recallCommand => \&recallCommand,
1157 ShellBang => \&shellBang,
1159 signalLevel => \&signalLevel,
1160 warnLevel => \&warnLevel,
1161 dieLevel => \&dieLevel,
1162 tkRunning => \&tkRunning,
1163 ornaments => \&ornaments,
1164 RemotePort => \&RemotePort,
1165 DollarCaretP => \&DollarCaretP,
1170 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1175 # Note that this list is not complete: several options not listed here
1176 # actually require that dumpvar.pl be loaded for them to work, but are
1177 # not in the table. A subsequent patch will correct this problem; for
1178 # the moment, we're just recommenting, and we are NOT going to change
1181 compactDump => 'dumpvar.pl',
1182 veryCompact => 'dumpvar.pl',
1183 quote => 'dumpvar.pl',
1188 There are a number of initialization-related variables which can be set
1189 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1190 variable. These are:
1194 =item C<$rl> - readline control XXX needs more explanation
1196 =item C<$warnLevel> - whether or not debugger takes over warning handling
1198 =item C<$dieLevel> - whether or not debugger takes over die handling
1200 =item C<$signalLevel> - whether or not debugger takes over signal handling
1202 =item C<$pre> - preprompt actions (array reference)
1204 =item C<$post> - postprompt actions (array reference)
1208 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1210 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1216 # These guys may be defined in $ENV{PERL5DB} :
1217 $rl = 1 unless defined $rl;
1218 $warnLevel = 1 unless defined $warnLevel;
1219 $dieLevel = 1 unless defined $dieLevel;
1220 $signalLevel = 1 unless defined $signalLevel;
1221 $pre = [] unless defined $pre;
1222 $post = [] unless defined $post;
1223 $pretype = [] unless defined $pretype;
1224 $CreateTTY = 3 unless defined $CreateTTY;
1225 $CommandSet = '580' unless defined $CommandSet;
1230 share($signalLevel);
1240 The default C<die>, C<warn>, and C<signal> handlers are set up.
1244 warnLevel($warnLevel);
1245 dieLevel($dieLevel);
1246 signalLevel($signalLevel);
1250 The pager to be used is needed next. We try to get it from the
1251 environment first. If it's not defined there, we try to find it in
1252 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1253 then call the C<pager()> function to save the pager name.
1257 # This routine makes sure $pager is set up so that '|' can use it.
1260 # If PAGER is defined in the environment, use it.
1264 # If not, see if Config.pm defines it.
1265 : eval { require Config }
1266 && defined $Config::Config{pager}
1267 ? $Config::Config{pager}
1269 # If not, fall back to 'more'.
1272 unless defined $pager;
1276 We set up the command to be used to access the man pages, the command
1277 recall character (C<!> unless otherwise defined) and the shell escape
1278 character (C<!> unless otherwise defined). Yes, these do conflict, and
1279 neither works in the debugger at the moment.
1285 # Set up defaults for command recall and shell escape (note:
1286 # these currently don't work in linemode debugging).
1287 &recallCommand("!") unless defined $prc;
1288 &shellBang("!") unless defined $psh;
1292 We then set up the gigantic string containing the debugger help.
1293 We also set the limit on the number of arguments we'll display during a
1300 # If we didn't get a default for the length of eval/stack trace args,
1302 $maxtrace = 400 unless defined $maxtrace;
1304 =head2 SETTING UP THE DEBUGGER GREETING
1306 The debugger I<greeting> helps to inform the user how many debuggers are
1307 running, and whether the current debugger is the primary or a child.
1309 If we are the primary, we just hang onto our pid so we'll have it when
1310 or if we start a child debugger. If we are a child, we'll set things up
1311 so we'll have a unique greeting and so the parent will give us our own
1314 We save the current contents of the C<PERLDB_PIDS> environment variable
1315 because we mess around with it. We'll also need to hang onto it because
1316 we'll need it if we restart.
1318 Child debuggers make a label out of the current PID structure recorded in
1319 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1320 yet so the parent will give them one later via C<resetterm()>.
1324 # Save the current contents of the environment; we're about to
1325 # much with it. We'll need this if we have to restart.
1326 $ini_pids = $ENV{PERLDB_PIDS};
1328 if ( defined $ENV{PERLDB_PIDS} ) {
1330 # We're a child. Make us a label out of the current PID structure
1331 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1332 # a term yet so the parent will give us one later via resetterm().
1334 my $env_pids = $ENV{PERLDB_PIDS};
1335 $pids = "[$env_pids]";
1337 # Unless we are on OpenVMS, all programs under the DCL shell run under
1340 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1344 $ENV{PERLDB_PIDS} .= "->$$";
1348 } ## end if (defined $ENV{PERLDB_PIDS...
1351 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1352 # child debugger, and mark us as the parent, so we'll know to set up
1353 # more TTY's is we have to.
1354 $ENV{PERLDB_PIDS} = "$$";
1361 # Sets up $emacs as a synonym for $slave_editor.
1362 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1364 =head2 READING THE RC FILE
1366 The debugger will read a file of initialization options if supplied. If
1367 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1371 # As noted, this test really doesn't check accurately that the debugger
1372 # is running at a terminal or not.
1374 my $dev_tty = '/dev/tty';
1375 $dev_tty = 'TT:' if ($^O eq 'VMS');
1376 if ( -e $dev_tty ) { # this is the wrong metric!
1377 $rcfile = ".perldb";
1380 $rcfile = "perldb.ini";
1385 The debugger does a safety test of the file to be read. It must be owned
1386 either by the current user or root, and must only be writable by the owner.
1390 # This wraps a safety test around "do" to read and evaluate the init file.
1392 # This isn't really safe, because there's a race
1393 # between checking and opening. The solution is to
1394 # open and fstat the handle, but then you have to read and
1395 # eval the contents. But then the silly thing gets
1396 # your lexical scope, which is unfortunate at best.
1400 # Just exactly what part of the word "CORE::" don't you understand?
1401 local $SIG{__WARN__};
1402 local $SIG{__DIE__};
1404 unless ( is_safe_file($file) ) {
1405 CORE::warn <<EO_GRIPE;
1406 perldb: Must not source insecure rcfile $file.
1407 You or the superuser must be the owner, and it must not
1408 be writable by anyone but its owner.
1411 } ## end unless (is_safe_file($file...
1414 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1415 } ## end sub safe_do
1417 # This is the safety test itself.
1419 # Verifies that owner is either real user or superuser and that no
1420 # one but owner may write to it. This function is of limited use
1421 # when called on a path instead of upon a handle, because there are
1422 # no guarantees that filename (by dirent) whose file (by ino) is
1423 # eventually accessed is the same as the one tested.
1424 # Assumes that the file's existence is not in doubt.
1427 stat($path) || return; # mysteriously vaporized
1428 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1430 return 0 if $uid != 0 && $uid != $<;
1431 return 0 if $mode & 022;
1433 } ## end sub is_safe_file
1435 # If the rcfile (whichever one we decided was the right one to read)
1436 # exists, we safely do it.
1438 safe_do("./$rcfile");
1441 # If there isn't one here, try the user's home directory.
1442 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1443 safe_do("$ENV{HOME}/$rcfile");
1446 # Else try the login directory.
1447 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1448 safe_do("$ENV{LOGDIR}/$rcfile");
1451 # If the PERLDB_OPTS variable has options in it, parse those out next.
1452 if ( defined $ENV{PERLDB_OPTS} ) {
1453 parse_options( $ENV{PERLDB_OPTS} );
1458 The last thing we do during initialization is determine which subroutine is
1459 to be used to obtain a new terminal when a new debugger is started. Right now,
1460 the debugger only handles X Windows, OS/2, and Mac OS X (darwin).
1464 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1465 # Works if you're running an xterm or xterm-like window, or you're on
1466 # OS/2, or on Mac OS X. This may need some expansion.
1468 if (not defined &get_fork_TTY) # only if no routine exists
1470 if (defined $ENV{TERM} # If we know what kind
1471 # of terminal this is,
1472 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1473 and defined $ENV{DISPLAY} # and what display it's on,
1476 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1478 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1479 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1481 elsif ( $^O eq 'darwin' # If this is Mac OS X
1482 and defined $ENV{TERM_PROGRAM} # and we're running inside
1483 and $ENV{TERM_PROGRAM}
1484 eq 'Apple_Terminal' # Terminal.app
1487 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1489 } ## end if (not defined &get_fork_TTY...
1491 # untaint $^O, which may have been tainted by the last statement.
1492 # see bug [perl #24674]
1496 # Here begin the unreadable code. It needs fixing.
1498 =head2 RESTART PROCESSING
1500 This section handles the restart command. When the C<R> command is invoked, it
1501 tries to capture all of the state it can into environment variables, and
1502 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1503 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1504 the R command stuffed into the environment variables.
1506 PERLDB_RESTART - flag only, contains no restart data itself.
1507 PERLDB_HIST - command history, if it's available
1508 PERLDB_ON_LOAD - breakpoints set by the rc file
1509 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1510 PERLDB_VISITED - files that had breakpoints
1511 PERLDB_FILE_... - breakpoints for a file
1512 PERLDB_OPT - active options
1513 PERLDB_INC - the original @INC
1514 PERLDB_PRETYPE - preprompt debugger actions
1515 PERLDB_PRE - preprompt Perl code
1516 PERLDB_POST - post-prompt Perl code
1517 PERLDB_TYPEAHEAD - typeahead captured by readline()
1519 We chug through all these variables and plug the values saved in them
1520 back into the appropriate spots in the debugger.
1524 if ( exists $ENV{PERLDB_RESTART} ) {
1526 # We're restarting, so we don't need the flag that says to restart anymore.
1527 delete $ENV{PERLDB_RESTART};
1530 @hist = get_list('PERLDB_HIST');
1531 %break_on_load = get_list("PERLDB_ON_LOAD");
1532 %postponed = get_list("PERLDB_POSTPONE");
1536 share(%break_on_load);
1539 # restore breakpoints/actions
1540 my @had_breakpoints = get_list("PERLDB_VISITED");
1541 for ( 0 .. $#had_breakpoints ) {
1542 my %pf = get_list("PERLDB_FILE_$_");
1543 $postponed_file{ $had_breakpoints[$_] } = \%pf if %pf;
1547 my %opt = get_list("PERLDB_OPT");
1549 while ( ( $opt, $val ) = each %opt ) {
1550 $val =~ s/[\\\']/\\$1/g;
1551 parse_options("$opt'$val'");
1554 # restore original @INC
1555 @INC = get_list("PERLDB_INC");
1558 # return pre/postprompt actions and typeahead buffer
1559 $pretype = [ get_list("PERLDB_PRETYPE") ];
1560 $pre = [ get_list("PERLDB_PRE") ];
1561 $post = [ get_list("PERLDB_POST") ];
1562 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1563 } ## end if (exists $ENV{PERLDB_RESTART...
1565 =head2 SETTING UP THE TERMINAL
1567 Now, we'll decide how the debugger is going to interact with the user.
1568 If there's no TTY, we set the debugger to run non-stop; there's not going
1569 to be anyone there to enter commands.
1580 If there is a TTY, we have to determine who it belongs to before we can
1581 proceed. If this is a slave editor or graphical debugger (denoted by
1582 the first command-line switch being '-emacs'), we shift this off and
1583 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1589 # Is Perl being run from a slave editor or graphical debugger?
1590 # If so, don't use readline, and set $slave_editor = 1.
1592 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1593 $rl = 0, shift(@main::ARGV) if $slave_editor;
1595 #require Term::ReadLine;
1599 We then determine what the console should be on various systems:
1603 =item * Cygwin - We use C<stdin> instead of a separate device.
1607 if ( $^O eq 'cygwin' ) {
1609 # /dev/tty is binary. use stdin for textmode
1613 =item * Unix - use C</dev/tty>.
1617 elsif ( -e "/dev/tty" ) {
1618 $console = "/dev/tty";
1621 =item * Windows or MSDOS - use C<con>.
1625 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1629 =item * MacOS - use C<Dev:Console:Perl Debug> if this is the MPW version; C<Dev:
1632 Note that Mac OS X returns C<darwin>, not C<MacOS>. Also note that the debugger doesn't do anything special for C<darwin>. Maybe it should.
1636 elsif ( $^O eq 'MacOS' ) {
1637 if ( $MacPerl::Version !~ /MPW/ ) {
1639 "Dev:Console:Perl Debug"; # Separate window for application
1642 $console = "Dev:Console";
1644 } ## end elsif ($^O eq 'MacOS')
1646 =item * VMS - use C<sys$command>.
1652 # everything else is ...
1653 $console = "sys\$command";
1660 Several other systems don't use a specific console. We C<undef $console>
1661 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1662 with a slave editor, Epoc).
1666 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1668 # /dev/tty is binary. use stdin for textmode
1672 if ( $^O eq 'NetWare' ) {
1674 # /dev/tty is binary. use stdin for textmode
1678 # In OS/2, we need to use STDIN to get textmode too, even though
1679 # it pretty much looks like Unix otherwise.
1680 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1685 # EPOC also falls into the 'got to use STDIN' camp.
1686 if ( $^O eq 'epoc' ) {
1692 If there is a TTY hanging around from a parent, we use that as the console.
1696 $console = $tty if defined $tty;
1698 =head2 SOCKET HANDLING
1700 The debugger is capable of opening a socket and carrying out a debugging
1701 session over the socket.
1703 If C<RemotePort> was defined in the options, the debugger assumes that it
1704 should try to start a debugging session on that port. It builds the socket
1705 and then tries to connect the input and output filehandles to it.
1709 # Handle socket stuff.
1711 if ( defined $remoteport ) {
1713 # If RemotePort was defined in the options, connect input and output
1716 $OUT = new IO::Socket::INET(
1718 PeerAddr => $remoteport,
1721 if ( !$OUT ) { die "Unable to connect to remote host: $remoteport\n"; }
1723 } ## end if (defined $remoteport)
1727 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1728 this is probably a situation where multiple debuggers are running (for example,
1729 a backticked command that starts up another debugger). We create a new IN and
1730 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1738 # Two debuggers running (probably a system or a backtick that invokes
1739 # the debugger itself under the running one). create a new IN and OUT
1740 # filehandle, and do the necessary mojo to create a new tty if we
1741 # know how, and we can.
1742 create_IN_OUT(4) if $CreateTTY & 4;
1745 # If we have a console, check to see if there are separate ins and
1746 # outs to open. (They are assumed identical if not.)
1748 my ( $i, $o ) = split /,/, $console;
1749 $o = $i unless defined $o;
1751 # read/write on in, or just read, or read on STDIN.
1753 || open( IN, "<$i" )
1754 || open( IN, "<&STDIN" );
1756 # read/write/create/clobber out, or write/create/clobber out,
1757 # or merge with STDERR, or merge with STDOUT.
1759 || open( OUT, ">$o" )
1760 || open( OUT, ">&STDERR" )
1761 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1763 } ## end if ($console)
1764 elsif ( not defined $console ) {
1766 # No console. Open STDIN.
1767 open( IN, "<&STDIN" );
1769 # merge with STDERR, or with STDOUT.
1770 open( OUT, ">&STDERR" )
1771 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1772 $console = 'STDIN/OUT';
1773 } ## end elsif (not defined $console)
1775 # Keep copies of the filehandles so that when the pager runs, it
1776 # can close standard input without clobbering ours.
1777 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1778 } ## end elsif (from if(defined $remoteport))
1780 # Unbuffer DB::OUT. We need to see responses right away.
1781 my $previous = select($OUT);
1782 $| = 1; # for DB::OUT
1785 # Line info goes to debugger output unless pointed elsewhere.
1786 # Pointing elsewhere makes it possible for slave editors to
1787 # keep track of file and position. We have both a filehandle
1788 # and a I/O description to keep track of.
1789 $LINEINFO = $OUT unless defined $LINEINFO;
1790 $lineinfo = $console unless defined $lineinfo;
1791 # share($LINEINFO); # <- unable to share globs
1796 To finish initialization, we show the debugger greeting,
1797 and then call the C<afterinit()> subroutine if there is one.
1801 # Show the debugger greeting.
1802 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1803 unless ($runnonstop) {
1806 if ( $term_pid eq '-1' ) {
1807 print $OUT "\nDaughter DB session started...\n";
1810 print $OUT "\nLoading DB routines from $header\n";
1813 $slave_editor ? "enabled" : "available", ".\n"
1816 "\nEnter h or `h h' for help, or `$doccmd perldebug' for more help.\n\n";
1817 } ## end else [ if ($term_pid eq '-1')
1818 } ## end unless ($runnonstop)
1819 } ## end else [ if ($notty)
1821 # XXX This looks like a bug to me.
1822 # Why copy to @ARGS and then futz with @args?
1825 # Make sure backslashes before single quotes are stripped out, and
1826 # keep args unless they are numeric (XXX why?)
1827 # s/\'/\\\'/g; # removed while not justified understandably
1828 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1831 # If there was an afterinit() sub defined, call it. It will get
1832 # executed in our scope, so it can fiddle with debugger globals.
1833 if ( defined &afterinit ) { # May be defined in $rcfile
1837 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1840 ############################################################ Subroutines
1846 This gigantic subroutine is the heart of the debugger. Called before every
1847 statement, its job is to determine if a breakpoint has been reached, and
1848 stop if so; read commands from the user, parse them, and execute
1849 them, and hen send execution off to the next statement.
1851 Note that the order in which the commands are processed is very important;
1852 some commands earlier in the loop will actually alter the C<$cmd> variable
1853 to create other commands to be executed later. This is all highly I<optimized>
1854 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1855 see what's happening in any given command.
1861 # lock the debugger and get the thread id for the prompt
1864 if ($ENV{PERL5DB_THREADED}) {
1865 $tid = eval { "[".threads->tid."]" };
1868 # Check for whether we should be running continuously or not.
1869 # _After_ the perl program is compiled, $single is set to 1:
1870 if ( $single and not $second_time++ ) {
1872 # Options say run non-stop. Run until we get an interrupt.
1873 if ($runnonstop) { # Disable until signal
1874 # If there's any call stack in place, turn off single
1875 # stepping into subs throughout the stack.
1876 for ( $i = 0 ; $i <= $stack_depth ; ) {
1877 $stack[ $i++ ] &= ~1;
1880 # And we are now no longer in single-step mode.
1883 # If we simply returned at this point, we wouldn't get
1884 # the trace info. Fall on through.
1886 } ## end if ($runnonstop)
1888 elsif ($ImmediateStop) {
1890 # We are supposed to stop here; XXX probably a break.
1891 $ImmediateStop = 0; # We've processed it; turn it off
1892 $signal = 1; # Simulate an interrupt to force
1893 # us into the command loop
1895 } ## end if ($single and not $second_time...
1897 # If we're in single-step mode, or an interrupt (real or fake)
1898 # has occurred, turn off non-stop mode.
1899 $runnonstop = 0 if $single or $signal;
1901 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1902 # The code being debugged may have altered them.
1905 # Since DB::DB gets called after every line, we can use caller() to
1906 # figure out where we last were executing. Sneaky, eh? This works because
1907 # caller is returning all the extra information when called from the
1909 local ( $package, $filename, $line ) = caller;
1910 local $filename_ini = $filename;
1912 # set up the context for DB::eval, so it can properly execute
1913 # code on behalf of the user. We add the package in so that the
1914 # code is eval'ed in the proper package (not in the debugger!).
1915 local $usercontext =
1916 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' . "package $package;";
1918 # Create an alias to the active file magical array to simplify
1920 local (*dbline) = $main::{ '_<' . $filename };
1922 # we need to check for pseudofiles on Mac OS (these are files
1923 # not attached to a filename, but instead stored in Dev:Pseudo)
1924 if ( $^O eq 'MacOS' && $#dbline < 0 ) {
1925 $filename_ini = $filename = 'Dev:Pseudo';
1926 *dbline = $main::{ '_<' . $filename };
1929 # Last line in the program.
1930 local $max = $#dbline;
1932 # if we have something here, see if we should break.
1934 && ( ( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1937 # Stop if the stop criterion says to just stop.
1938 if ( $stop eq '1' ) {
1942 # It's a conditional stop; eval it in the user's context and
1943 # see if we should stop. If so, remove the one-time sigil.
1945 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1947 $dbline{$line} =~ s/;9($|\0)/$1/;
1949 } ## end if ($dbline{$line} && ...
1951 # Preserve the current stop-or-not, and see if any of the W
1952 # (watch expressions) has changed.
1953 my $was_signal = $signal;
1955 # If we have any watch expressions ...
1957 for ( my $n = 0 ; $n <= $#to_watch ; $n++ ) {
1958 $evalarg = $to_watch[$n];
1959 local $onetimeDump; # Tell DB::eval() to not output results
1961 # Fix context DB::eval() wants to return an array, but
1962 # we need a scalar here.
1963 my ($val) = join( "', '", &eval );
1964 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
1967 if ( $val ne $old_watch[$n] ) {
1969 # Yep! Show the difference, and fake an interrupt.
1972 Watchpoint $n:\t$to_watch[$n] changed:
1973 old value:\t$old_watch[$n]
1976 $old_watch[$n] = $val;
1977 } ## end if ($val ne $old_watch...
1978 } ## end for (my $n = 0 ; $n <= ...
1979 } ## end if ($trace & 2)
1981 =head2 C<watchfunction()>
1983 C<watchfunction()> is a function that can be defined by the user; it is a
1984 function which will be run on each entry to C<DB::DB>; it gets the
1985 current package, filename, and line as its parameters.
1987 The watchfunction can do anything it likes; it is executing in the
1988 debugger's context, so it has access to all of the debugger's internal
1989 data structures and functions.
1991 C<watchfunction()> can control the debugger's actions. Any of the following
1992 will cause the debugger to return control to the user's program after
1993 C<watchfunction()> executes:
1999 Returning a false value from the C<watchfunction()> itself.
2003 Altering C<$single> to a false value.
2007 Altering C<$signal> to a false value.
2011 Turning off the C<4> bit in C<$trace> (this also disables the
2012 check for C<watchfunction()>. This can be done with
2020 # If there's a user-defined DB::watchfunction, call it with the
2021 # current package, filename, and line. The function executes in
2023 if ( $trace & 4 ) { # User-installed watch
2025 if watchfunction( $package, $filename, $line )
2028 and not( $trace & ~4 );
2029 } ## end if ($trace & 4)
2031 # Pick up any alteration to $signal in the watchfunction, and
2032 # turn off the signal now.
2033 $was_signal = $signal;
2036 =head2 GETTING READY TO EXECUTE COMMANDS
2038 The debugger decides to take control if single-step mode is on, the
2039 C<t> command was entered, or the user generated a signal. If the program
2040 has fallen off the end, we set things up so that entering further commands
2041 won't cause trouble, and we say that the program is over.
2045 # Check to see if we should grab control ($single true,
2046 # trace set appropriately, or we got a signal).
2047 if ( $single || ( $trace & 1 ) || $was_signal ) {
2049 # Yes, grab control.
2050 if ($slave_editor) {
2052 # Tell the editor to update its position.
2053 $position = "\032\032$filename:$line:0\n";
2054 print_lineinfo($position);
2059 Special check: if we're in package C<DB::fake>, we've gone through the
2060 C<END> block at least once. We set up everything so that we can continue
2061 to enter commands and have a valid context to be in.
2065 elsif ( $package eq 'DB::fake' ) {
2067 # Fallen off the end already.
2070 Debugged program terminated. Use B<q> to quit or B<R> to restart,
2071 use B<o> I<inhibit_exit> to avoid stopping after program termination,
2072 B<h q>, B<h R> or B<h o> to get additional info.
2075 # Set the DB::eval context appropriately.
2078 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;'
2079 . "package $package;"; # this won't let them modify, alas
2080 } ## end elsif ($package eq 'DB::fake')
2084 If the program hasn't finished executing, we scan forward to the
2085 next executable line, print that out, build the prompt from the file and line
2086 number information, and print that.
2092 # Still somewhere in the midst of execution. Set up the
2094 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
2095 # Perl 5 ones (sorry, we don't print Klingon
2098 $prefix = $sub =~ /::/ ? "" : "${'package'}::";
2099 $prefix .= "$sub($filename:";
2100 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" );
2102 # Break up the prompt if it's really long.
2103 if ( length($prefix) > 30 ) {
2104 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
2110 $position = "$prefix$line$infix$dbline[$line]$after";
2113 # Print current line info, indenting if necessary.
2115 print_lineinfo( ' ' x $stack_depth,
2116 "$line:\t$dbline[$line]$after" );
2119 print_lineinfo($position);
2122 # Scan forward, stopping at either the end or the next
2124 for ( $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i )
2127 # Drop out on null statements, block closers, and comments.
2128 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
2130 # Drop out if the user interrupted us.
2133 # Append a newline if the line doesn't have one. Can happen
2134 # in eval'ed text, for instance.
2135 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" );
2137 # Next executable line.
2138 $incr_pos = "$prefix$i$infix$dbline[$i]$after";
2139 $position .= $incr_pos;
2142 # Print it indented if tracing is on.
2143 print_lineinfo( ' ' x $stack_depth,
2144 "$i:\t$dbline[$i]$after" );
2147 print_lineinfo($incr_pos);
2149 } ## end for ($i = $line + 1 ; $i...
2150 } ## end else [ if ($slave_editor)
2151 } ## end if ($single || ($trace...
2155 If there's an action to be executed for the line we stopped at, execute it.
2156 If there are any preprompt actions, execute those as well.
2160 # If there's an action, do it now.
2161 $evalarg = $action, &eval if $action;
2163 # Are we nested another level (e.g., did we evaluate a function
2164 # that had a breakpoint in it at the debugger prompt)?
2165 if ( $single || $was_signal ) {
2167 # Yes, go down a level.
2168 local $level = $level + 1;
2170 # Do any pre-prompt actions.
2171 foreach $evalarg (@$pre) {
2175 # Complain about too much recursion if we passed the limit.
2176 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
2179 # The line we're currently on. Set $incr to -1 to stay here
2180 # until we get a command that tells us to advance.
2182 $incr = -1; # for backward motion.
2184 # Tack preprompt debugger actions ahead of any actual input.
2185 @typeahead = ( @$pretype, @typeahead );
2187 =head2 WHERE ARE WE?
2189 XXX Relocate this section?
2191 The debugger normally shows the line corresponding to the current line of
2192 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2193 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2195 C<$incr> controls by how many lines the I<current> line should move forward
2196 after a command is executed. If set to -1, this indicates that the I<current>
2197 line shouldn't change.
2199 C<$start> is the I<current> line. It is used for things like knowing where to
2200 move forwards or backwards from when doing an C<L> or C<-> command.
2202 C<$max> tells the debugger where the last line of the current file is. It's
2203 used to terminate loops most often.
2205 =head2 THE COMMAND LOOP
2207 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2214 The outer part of the loop, starting at the C<CMD> label. This loop
2215 reads a command and then executes it.
2219 The inner part of the loop, starting at the C<PIPE> label. This part
2220 is wholly contained inside the C<CMD> block and only executes a command.
2221 Used to handle commands running inside a pager.
2225 So why have two labels to restart the loop? Because sometimes, it's easier to
2226 have a command I<generate> another command and then re-execute the loop to do
2227 the new command. This is faster, but perhaps a bit more convoluted.
2231 # The big command dispatch loop. It keeps running until the
2232 # user yields up control again.
2234 # If we have a terminal for input, and we get something back
2235 # from readline(), keep on processing.
2239 # We have a terminal, or can get one ...
2240 ( $term || &setterm ),
2242 # ... and it belogs to this PID or we get one for this PID ...
2243 ( $term_pid == $$ or resetterm(1) ),
2245 # ... and we got a line of command input ...
2248 "$pidprompt $tid DB"
2251 . ( '>' x $level ) . " "
2258 # ... try to execute the input as debugger commands.
2260 # Don't stop running.
2263 # No signal is active.
2266 # Handle continued commands (ending with \):
2267 $cmd =~ s/\\$/\n/ && do {
2268 $cmd .= &readline(" cont: ");
2272 =head4 The null command
2274 A newline entered by itself means I<re-execute the last command>. We grab the
2275 command out of C<$laststep> (where it was recorded previously), and copy it
2276 back into C<$cmd> to be executed below. If there wasn't any previous command,
2277 we'll do nothing below (no command will match). If there was, we also save it
2278 in the command history and fall through to allow the command parsing to pick
2283 # Empty input means repeat the last command.
2284 $cmd =~ /^$/ && ( $cmd = $laststep );
2285 chomp($cmd); # get rid of the annoying extra newline
2286 push( @hist, $cmd ) if length($cmd) > 1;
2287 push( @truehist, $cmd );
2291 # This is a restart point for commands that didn't arrive
2292 # via direct user input. It allows us to 'redo PIPE' to
2293 # re-execute command processing without reading a new command.
2295 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2296 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
2297 ($i) = split( /\s+/, $cmd );
2299 =head3 COMMAND ALIASES
2301 The debugger can create aliases for commands (these are stored in the
2302 C<%alias> hash). Before a command is executed, the command loop looks it up
2303 in the alias hash and substitutes the contents of the alias for the command,
2304 completely replacing it.
2308 # See if there's an alias for the command, and set it up if so.
2311 # Squelch signal handling; we want to keep control here
2312 # if something goes loco during the alias eval.
2313 local $SIG{__DIE__};
2314 local $SIG{__WARN__};
2316 # This is a command, so we eval it in the DEBUGGER's
2317 # scope! Otherwise, we can't see the special debugger
2318 # variables, or get to the debugger's subs. (Well, we
2319 # _could_, but why make it even more complicated?)
2320 eval "\$cmd =~ $alias{$i}";
2323 print $OUT "Couldn't evaluate `$i' alias: $@";
2326 } ## end if ($alias{$i})
2328 =head3 MAIN-LINE COMMANDS
2330 All of these commands work up to and after the program being debugged has
2335 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2336 try to execute further, cleaning any restart-related stuff out of the
2337 environment, and executing with the last value of C<$?>.
2341 $cmd =~ /^q$/ && do {
2349 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2353 $cmd =~ /^t$/ && do {
2356 print $OUT "Trace = "
2357 . ( ( $trace & 1 ) ? "on" : "off" ) . "\n";
2361 =head4 C<S> - list subroutines matching/not matching a pattern
2363 Walks through C<%sub>, checking to see whether or not to print the name.
2367 $cmd =~ /^S(\s+(!)?(.+))?$/ && do {
2369 $Srev = defined $2; # Reverse scan?
2370 $Spatt = $3; # The pattern (if any) to use.
2371 $Snocheck = !defined $1; # No args - print all subs.
2373 # Need to make these sane here.
2377 # Search through the debugger's magical hash of subs.
2378 # If $nocheck is true, just print the sub name.
2379 # Otherwise, check it against the pattern. We then use
2380 # the XOR trick to reverse the condition as required.
2381 foreach $subname ( sort( keys %sub ) ) {
2382 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2383 print $OUT $subname, "\n";
2389 =head4 C<X> - list variables in current package
2391 Since the C<V> command actually processes this, just change this to the
2392 appropriate C<V> command and fall through.
2396 $cmd =~ s/^X\b/V $package/;
2398 =head4 C<V> - list variables
2400 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2404 # Bare V commands get the currently-being-debugged package
2406 $cmd =~ /^V$/ && do {
2407 $cmd = "V $package";
2410 # V - show variables in package.
2411 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
2413 # Save the currently selected filehandle and
2414 # force output to debugger's filehandle (dumpvar
2415 # just does "print" for output).
2416 local ($savout) = select($OUT);
2418 # Grab package name and variables to dump.
2420 @vars = split( ' ', $2 );
2422 # If main::dumpvar isn't here, get it.
2423 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
2424 if ( defined &main::dumpvar ) {
2426 # We got it. Turn off subroutine entry/exit messages
2427 # for the moment, along with return values.
2431 # must detect sigpipe failures - not catching
2432 # then will cause the debugger to die.
2436 defined $option{dumpDepth}
2437 ? $option{dumpDepth}
2438 : -1, # assume -1 unless specified
2443 # The die doesn't need to include the $@, because
2444 # it will automatically get propagated for us.
2446 die unless $@ =~ /dumpvar print failed/;
2448 } ## end if (defined &main::dumpvar)
2451 # Couldn't load dumpvar.
2452 print $OUT "dumpvar.pl not available.\n";
2455 # Restore the output filehandle, and go round again.
2460 =head4 C<x> - evaluate and print an expression
2462 Hands the expression off to C<DB::eval>, setting it up to print the value
2463 via C<dumpvar.pl> instead of just printing it directly.
2467 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval()
2468 $onetimeDump = 'dump'; # main::dumpvar shows the output
2470 # handle special "x 3 blah" syntax XXX propagate
2471 # doc back to special variables.
2472 if ( $cmd =~ s/^\s*(\d+)(?=\s)/ / ) {
2473 $onetimedumpDepth = $1;
2477 =head4 C<m> - print methods
2479 Just uses C<DB::methods> to determine what methods are available.
2483 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do {
2488 # m expr - set up DB::eval to do the work
2489 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval()
2490 $onetimeDump = 'methods'; # method output gets used there
2493 =head4 C<f> - switch files
2497 $cmd =~ /^f\b\s*(.*)/ && do {
2501 # help for no arguments (old-style was return from sub).
2504 "The old f command is now the r command.\n"; # hint
2505 print $OUT "The new f command switches filenames.\n";
2507 } ## end if (!$file)
2509 # if not in magic file list, try a close match.
2510 if ( !defined $main::{ '_<' . $file } ) {
2511 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2513 $try = substr( $try, 2 );
2514 print $OUT "Choosing $try matching `$file':\n";
2517 } ## end if (($try) = grep(m#^_<.*$file#...
2518 } ## end if (!defined $main::{ ...
2520 # If not successfully switched now, we failed.
2521 if ( !defined $main::{ '_<' . $file } ) {
2522 print $OUT "No file matching `$file' is loaded.\n";
2526 # We switched, so switch the debugger internals around.
2527 elsif ( $file ne $filename ) {
2528 *dbline = $main::{ '_<' . $file };
2533 } ## end elsif ($file ne $filename)
2535 # We didn't switch; say we didn't.
2537 print $OUT "Already in $file.\n";
2542 =head4 C<.> - return to last-executed line.
2544 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2545 and then we look up the line in the magical C<%dbline> hash.
2550 $cmd =~ /^\.$/ && do {
2551 $incr = -1; # stay at current line
2553 # Reset everything to the old location.
2555 $filename = $filename_ini;
2556 *dbline = $main::{ '_<' . $filename };
2560 print_lineinfo($position);
2564 =head4 C<-> - back one window
2566 We change C<$start> to be one window back; if we go back past the first line,
2567 we set it to be the first line. We ser C<$incr> to put us back at the
2568 currently-executing line, and then put a C<l $start +> (list one window from
2569 C<$start>) in C<$cmd> to be executed later.
2573 # - - back a window.
2574 $cmd =~ /^-$/ && do {
2576 # back up by a window; go to 1 if back too far.
2577 $start -= $incr + $window + 1;
2578 $start = 1 if $start <= 0;
2579 $incr = $window - 1;
2581 # Generate and execute a "l +" command (handled below).
2582 $cmd = 'l ' . ($start) . '+';
2585 =head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, {, {{>
2587 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2588 problems, most notably that the default case of several commands destroying
2589 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2590 retain the old commands for those who were used to using them or who preferred
2591 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2592 deal with them instead of processing them in-line.
2596 # All of these commands were remapped in perl 5.8.0;
2597 # we send them off to the secondary dispatcher (see below).
2598 $cmd =~ /^([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do {
2599 &cmd_wrapper( $1, $2, $line );
2603 =head4 C<y> - List lexicals in higher scope
2605 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2606 above the current one and then displays then using C<dumpvar.pl>.
2610 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do {
2612 # See if we've got the necessary support.
2613 eval { require PadWalker; PadWalker->VERSION(0.08) }
2616 ? "PadWalker module not found - please install\n"
2621 # Load up dumpvar if we don't have it. If we can, that is.
2622 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
2623 defined &main::dumpvar
2624 or print $OUT "dumpvar.pl not available.\n"
2627 # Got all the modules we need. Find them and print them.
2628 my @vars = split( ' ', $2 || '' );
2631 my $h = eval { PadWalker::peek_my( ( $1 || 0 ) + 1 ) };
2633 # Oops. Can't find it.
2634 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2636 # Show the desired vars with dumplex().
2637 my $savout = select($OUT);
2639 # Have dumplex dump the lexicals.
2640 dumpvar::dumplex( $_, $h->{$_},
2641 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
2648 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2650 All of the commands below this point don't work after the program being
2651 debugged has ended. All of them check to see if the program has ended; this
2652 allows the commands to be relocated without worrying about a 'line of
2653 demarcation' above which commands can be entered anytime, and below which
2656 =head4 C<n> - single step, but don't trace down into subs
2658 Done by setting C<$single> to 2, which forces subs to execute straight through
2659 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2660 so a null command knows what to re-execute.
2665 $cmd =~ /^n$/ && do {
2666 end_report(), next CMD if $finished and $level <= 1;
2668 # Single step, but don't enter subs.
2671 # Save for empty command (repeat last).
2676 =head4 C<s> - single-step, entering subs
2678 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2679 subs. Also saves C<s> as C<$lastcmd>.
2684 $cmd =~ /^s$/ && do {
2686 # Get out and restart the command loop if program
2688 end_report(), next CMD if $finished and $level <= 1;
2690 # Single step should enter subs.
2693 # Save for empty command (repeat last).
2698 =head4 C<c> - run continuously, setting an optional breakpoint
2700 Most of the code for this command is taken up with locating the optional
2701 breakpoint, which is either a subroutine name or a line number. We set
2702 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2703 in this and all call levels above this one.
2707 # c - start continuous execution.
2708 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do {
2710 # Hey, show's over. The debugged program finished
2711 # executing already.
2712 end_report(), next CMD if $finished and $level <= 1;
2714 # Capture the place to put a one-time break.
2717 # Probably not needed, since we finish an interactive
2718 # sub-session anyway...
2719 # local $filename = $filename;
2720 # local *dbline = *dbline; # XXX Would this work?!
2722 # The above question wonders if localizing the alias
2723 # to the magic array works or not. Since it's commented
2724 # out, we'll just leave that to speculation for now.
2726 # If the "subname" isn't all digits, we'll assume it
2727 # is a subroutine name, and try to find it.
2728 if ( $subname =~ /\D/ ) { # subroutine name
2729 # Qualify it to the current package unless it's
2730 # already qualified.
2731 $subname = $package . "::" . $subname
2732 unless $subname =~ /::/;
2734 # find_sub will return "file:line_number" corresponding
2735 # to where the subroutine is defined; we call find_sub,
2736 # break up the return value, and assign it in one
2738 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2740 # Force the line number to be numeric.
2743 # If we got a line number, we found the sub.
2746 # Switch all the debugger's internals around so
2747 # we're actually working with that file.
2749 *dbline = $main::{ '_<' . $filename };
2751 # Mark that there's a breakpoint in this file.
2752 $had_breakpoints{$filename} |= 1;
2754 # Scan forward to the first executable line
2755 # after the 'sub whatever' line.
2757 ++$i while $dbline[$i] == 0 && $i < $max;
2760 # We didn't find a sub by that name.
2762 print $OUT "Subroutine $subname not found.\n";
2765 } ## end if ($subname =~ /\D/)
2767 # At this point, either the subname was all digits (an
2768 # absolute line-break request) or we've scanned through
2769 # the code following the definition of the sub, looking
2770 # for an executable, which we may or may not have found.
2772 # If $i (which we set $subname from) is non-zero, we
2773 # got a request to break at some line somewhere. On
2774 # one hand, if there wasn't any real subroutine name
2775 # involved, this will be a request to break in the current
2776 # file at the specified line, so we have to check to make
2777 # sure that the line specified really is breakable.
2779 # On the other hand, if there was a subname supplied, the
2780 # preceding block has moved us to the proper file and
2781 # location within that file, and then scanned forward
2782 # looking for the next executable line. We have to make
2783 # sure that one was found.
2785 # On the gripping hand, we can't do anything unless the
2786 # current value of $i points to a valid breakable line.
2791 if ( $dbline[$i] == 0 ) {
2792 print $OUT "Line $i not breakable.\n";
2796 # Yes. Set up the one-time-break sigil.
2797 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2800 # Turn off stack tracing from here up.
2801 for ( $i = 0 ; $i <= $stack_depth ; ) {
2802 $stack[ $i++ ] &= ~1;
2807 =head4 C<r> - return from a subroutine
2809 For C<r> to work properly, the debugger has to stop execution again
2810 immediately after the return is executed. This is done by forcing
2811 single-stepping to be on in the call level above the current one. If
2812 we are printing return values when a C<r> is executed, set C<$doret>
2813 appropriately, and force us out of the command loop.
2817 # r - return from the current subroutine.
2818 $cmd =~ /^r$/ && do {
2820 # Can't do anythign if the program's over.
2821 end_report(), next CMD if $finished and $level <= 1;
2823 # Turn on stack trace.
2824 $stack[$stack_depth] |= 1;
2826 # Print return value unless the stack is empty.
2827 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2831 =head4 C<T> - stack trace
2833 Just calls C<DB::print_trace>.
2837 $cmd =~ /^T$/ && do {
2838 print_trace( $OUT, 1 ); # skip DB
2842 =head4 C<w> - List window around current line.
2844 Just calls C<DB::cmd_w>.
2848 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w( 'w', $1 ); next CMD; };
2850 =head4 C<W> - watch-expression processing.
2852 Just calls C<DB::cmd_W>.
2856 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W( 'W', $1 ); next CMD; };
2858 =head4 C</> - search forward for a string in the source
2860 We take the argument and treat it as a pattern. If it turns out to be a
2861 bad one, we return the error we got from trying to C<eval> it and exit.
2862 If not, we create some code to do the search and C<eval> it so it can't
2867 $cmd =~ /^\/(.*)$/ && do {
2869 # The pattern as a string.
2872 # Remove the final slash.
2873 $inpat =~ s:([^\\])/$:$1:;
2875 # If the pattern isn't null ...
2876 if ( $inpat ne "" ) {
2878 # Turn of warn and die procesing for a bit.
2879 local $SIG{__DIE__};
2880 local $SIG{__WARN__};
2882 # Create the pattern.
2883 eval '$inpat =~ m' . "\a$inpat\a";
2886 # Oops. Bad pattern. No biscuit.
2887 # Print the eval error and go back for more
2893 } ## end if ($inpat ne "")
2895 # Set up to stop on wrap-around.
2898 # Don't move off the current line.
2901 # Done in eval so nothing breaks if the pattern
2902 # does something weird.
2905 # Move ahead one line.
2908 # Wrap if we pass the last line.
2909 $start = 1 if ($start > $max);
2911 # Stop if we have gotten back to this line again,
2912 last if ($start == $end);
2914 # A hit! (Note, though, that we are doing
2915 # case-insensitive matching. Maybe a qr//
2916 # expression would be better, so the user could
2917 # do case-sensitive matching if desired.
2918 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2919 if ($slave_editor) {
2920 # Handle proper escaping in the slave.
2921 print $OUT "\032\032$filename:$start:0\n";
2924 # Just print the line normally.
2925 print $OUT "$start:\t",$dbline[$start],"\n";
2927 # And quit since we found something.
2932 # If we wrapped, there never was a match.
2933 print $OUT "/$pat/: not found\n" if ( $start == $end );
2937 =head4 C<?> - search backward for a string in the source
2939 Same as for C</>, except the loop runs backwards.
2943 # ? - backward pattern search.
2944 $cmd =~ /^\?(.*)$/ && do {
2946 # Get the pattern, remove trailing question mark.
2948 $inpat =~ s:([^\\])\?$:$1:;
2950 # If we've got one ...
2951 if ( $inpat ne "" ) {
2953 # Turn off die & warn handlers.
2954 local $SIG{__DIE__};
2955 local $SIG{__WARN__};
2956 eval '$inpat =~ m' . "\a$inpat\a";
2960 # Ouch. Not good. Print the error.
2965 } ## end if ($inpat ne "")
2967 # Where we are now is where to stop after wraparound.
2970 # Don't move away from this line.
2973 # Search inside the eval to prevent pattern badness
2980 # Wrap if we pass the first line.
2982 $start = $max if ($start <= 0);
2984 # Quit if we get back where we started,
2985 last if ($start == $end);
2988 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2989 if ($slave_editor) {
2990 # Yep, follow slave editor requirements.
2991 print $OUT "\032\032$filename:$start:0\n";
2994 # Yep, just print normally.
2995 print $OUT "$start:\t",$dbline[$start],"\n";
3003 # Say we failed if the loop never found anything,
3004 print $OUT "?$pat?: not found\n" if ( $start == $end );
3008 =head4 C<$rc> - Recall command
3010 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
3011 that the terminal supports history). It find the the command required, puts it
3012 into C<$cmd>, and redoes the loop to execute it.
3016 # $rc - recall command.
3017 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do {
3019 # No arguments, take one thing off history.
3020 pop(@hist) if length($cmd) > 1;
3022 # Relative (- found)?
3023 # Y - index back from most recent (by 1 if bare minus)
3024 # N - go to that particular command slot or the last
3025 # thing if nothing following.
3026 $i = $1 ? ( $#hist - ( $2 || 1 ) ) : ( $2 || $#hist );
3028 # Pick out the command desired.
3031 # Print the command to be executed and restart the loop
3032 # with that command in the buffer.
3033 print $OUT $cmd, "\n";
3037 =head4 C<$sh$sh> - C<system()> command
3039 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
3040 C<STDOUT> from getting messed up.
3044 # $sh$sh - run a shell command (if it's all ASCII).
3045 # Can't run shell commands with Unicode in the debugger, hmm.
3046 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do {
3053 =head4 C<$rc I<pattern> $rc> - Search command history
3055 Another command to manipulate C<@hist>: this one searches it with a pattern.
3056 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
3060 # $rc pattern $rc - find a command in the history.
3061 $cmd =~ /^$rc([^$rc].*)$/ && do {
3063 # Create the pattern to use.
3066 # Toss off last entry if length is >1 (and it always is).
3067 pop(@hist) if length($cmd) > 1;
3069 # Look backward through the history.
3070 for ( $i = $#hist ; $i ; --$i ) {
3072 # Stop if we find it.
3073 last if $hist[$i] =~ /$pat/;
3079 print $OUT "No such command!\n\n";
3083 # Found it. Put it in the buffer, print it, and process it.
3085 print $OUT $cmd, "\n";
3089 =head4 C<$sh> - Invoke a shell
3091 Uses C<DB::system> to invoke a shell.
3095 # $sh - start a shell.
3096 $cmd =~ /^$sh$/ && do {
3098 # Run the user's shell. If none defined, run Bourne.
3099 # We resume execution when the shell terminates.
3100 &system( $ENV{SHELL} || "/bin/sh" );
3104 =head4 C<$sh I<command>> - Force execution of a command in a shell
3106 Like the above, but the command is passed to the shell. Again, we use
3107 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3111 # $sh command - start a shell and run a command in it.
3112 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do {
3114 # XXX: using csh or tcsh destroys sigint retvals!
3115 #&system($1); # use this instead
3117 # use the user's shell, or Bourne if none defined.
3118 &system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3122 =head4 C<H> - display commands in history
3124 Prints the contents of C<@hist> (if any).
3128 $cmd =~ /^H\b\s*\*/ && do {
3129 @hist = @truehist = ();
3130 print $OUT "History cleansed\n";
3134 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
3136 # Anything other than negative numbers is ignored by
3137 # the (incorrect) pattern, so this test does nothing.
3138 $end = $2 ? ( $#hist - $2 ) : 0;
3140 # Set to the minimum if less than zero.
3141 $hist = 0 if $hist < 0;
3143 # Start at the end of the array.
3144 # Stay in while we're still above the ending value.
3145 # Tick back by one each time around the loop.
3146 for ( $i = $#hist ; $i > $end ; $i-- ) {
3148 # Print the command unless it has no arguments.
3149 print $OUT "$i: ", $hist[$i], "\n"
3150 unless $hist[$i] =~ /^.?$/;
3155 =head4 C<man, doc, perldoc> - look up documentation
3157 Just calls C<runman()> to print the appropriate document.
3161 # man, perldoc, doc - show manual pages.
3162 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do {
3169 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3170 the bottom of the loop.
3174 # p - print (no args): print $_.
3175 $cmd =~ s/^p$/print {\$DB::OUT} \$_/;
3177 # p - print the given expression.
3178 $cmd =~ s/^p\b/print {\$DB::OUT} /;
3180 =head4 C<=> - define command alias
3182 Manipulates C<%alias> to add or list command aliases.
3186 # = - set up a command alias.
3187 $cmd =~ s/^=\s*// && do {
3189 if ( length $cmd == 0 ) {
3191 # No args, get current aliases.
3192 @keys = sort keys %alias;
3194 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3196 # Creating a new alias. $k is alias name, $v is
3199 # can't use $_ or kill //g state
3200 for my $x ( $k, $v ) {
3202 # Escape "alarm" characters.
3206 # Substitute key for value, using alarm chars
3207 # as separators (which is why we escaped them in
3209 $alias{$k} = "s\a$k\a$v\a";
3211 # Turn off standard warn and die behavior.
3212 local $SIG{__DIE__};
3213 local $SIG{__WARN__};
3216 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3218 # Nope. Bad alias. Say so and get out.
3219 print $OUT "Can't alias $k to $v: $@\n";
3224 # We'll only list the new one.
3226 } ## end elsif (my ($k, $v) = ($cmd...
3228 # The argument is the alias to list.
3236 # Messy metaquoting: Trim the substiution code off.
3237 # We use control-G as the delimiter because it's not
3238 # likely to appear in the alias.
3239 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3242 print $OUT "$k\t= $1\n";
3244 elsif ( defined $alias{$k} ) {
3246 # Couldn't trim it off; just print the alias code.
3247 print $OUT "$k\t$alias{$k}\n";
3252 print "No alias for $k\n";
3254 } ## end for my $k (@keys)
3258 =head4 C<source> - read commands from a file.
3260 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3265 # source - read commands from a file (or pipe!) and execute.
3266 $cmd =~ /^source\s+(.*\S)/ && do {
3267 if ( open my $fh, $1 ) {
3269 # Opened OK; stick it in the list of file handles.
3275 &warn("Can't execute `$1': $!\n");
3280 =head4 C<save> - send current history to a file
3282 Takes the complete history, (not the shrunken version you see with C<H>),
3283 and saves it to the given filename, so it can be replayed using C<source>.
3285 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3289 # save source - write commands to a file for later use
3290 $cmd =~ /^save\s*(.*)$/ && do {
3291 my $file = $1 || '.perl5dbrc'; # default?
3292 if ( open my $fh, "> $file" ) {
3294 # chomp to remove extraneous newlines from source'd files
3295 chomp( my @truelist =
3296 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3298 print $fh join( "\n", @truelist );
3299 print "commands saved in $file\n";
3302 &warn("Can't save debugger commands in '$1': $!\n");
3307 =head4 C<R> - restart
3309 Restart the debugger session.
3311 =head4 C<rerun> - rerun the current session
3313 Return to any given position in the B<true>-history list
3317 # R - restart execution.
3318 # rerun - controlled restart execution.
3319 $cmd =~ /^(R|rerun\s*(.*))$/ && do {
3320 my @args = ($1 eq 'R' ? restart() : rerun($2));
3322 # Close all non-system fds for a clean restart. A more
3323 # correct method would be to close all fds that were not
3324 # open when the process started, but this seems to be
3325 # hard. See "debugger 'R'estart and open database
3326 # connections" on p5p.
3328 my $max_fd = 1024; # default if POSIX can't be loaded
3329 if (eval { require POSIX }) {
3330 $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX());
3333 if (defined $max_fd) {
3334 foreach ($^F+1 .. $max_fd-1) {
3335 next unless open FD_TO_CLOSE, "<&=$_";
3340 # And run Perl again. We use exec() to keep the
3341 # PID stable (and that way $ini_pids is still valid).
3342 exec(@args) || print $OUT "exec failed: $!\n";
3347 =head4 C<|, ||> - pipe output through the pager.
3349 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3350 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3351 pipe to the pager (restoring the output filehandles if this fails). If this
3352 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3353 set C<$signal>, sending us back into the debugger.
3355 We then trim off the pipe symbols and C<redo> the command loop at the
3356 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3361 # || - run command in the pager, with output to DB::OUT.
3362 $cmd =~ /^\|\|?\s*[^|]/ && do {
3363 if ( $pager =~ /^\|/ ) {
3365 # Default pager is into a pipe. Redirect I/O.
3366 open( SAVEOUT, ">&STDOUT" )
3367 || &warn("Can't save STDOUT");
3368 open( STDOUT, ">&OUT" )
3369 || &warn("Can't redirect STDOUT");
3370 } ## end if ($pager =~ /^\|/)
3373 # Not into a pipe. STDOUT is safe.
3374 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3377 # Fix up environment to record we have less if so.
3380 unless ( $piped = open( OUT, $pager ) ) {
3382 # Couldn't open pipe to pager.
3383 &warn("Can't pipe output to `$pager'");
3384 if ( $pager =~ /^\|/ ) {
3386 # Redirect I/O back again.
3387 open( OUT, ">&STDOUT" ) # XXX: lost message
3388 || &warn("Can't restore DB::OUT");
3389 open( STDOUT, ">&SAVEOUT" )
3390 || &warn("Can't restore STDOUT");
3392 } ## end if ($pager =~ /^\|/)
3395 # Redirect I/O. STDOUT already safe.
3396 open( OUT, ">&STDOUT" ) # XXX: lost message
3397 || &warn("Can't restore DB::OUT");
3400 } ## end unless ($piped = open(OUT,...
3402 # Set up broken-pipe handler if necessary.
3403 $SIG{PIPE} = \&DB::catch
3405 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
3407 # Save current filehandle, unbuffer out, and put it back.
3408 $selected = select(OUT);
3411 # Don't put it back if pager was a pipe.
3412 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
3414 # Trim off the pipe symbols and run the command now.
3415 $cmd =~ s/^\|+\s*//;
3419 =head3 END OF COMMAND PARSING
3421 Anything left in C<$cmd> at this point is a Perl expression that we want to
3422 evaluate. We'll always evaluate in the user's context, and fully qualify
3423 any variables we might want to address in the C<DB> package.
3427 # t - turn trace on.
3428 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3430 # s - single-step. Remember the last command was 's'.
3431 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' };
3433 # n - single-step, but not into subs. Remember last command
3435 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' };
3439 # Make sure the flag that says "the debugger's running" is
3440 # still on, to make sure we get control again.
3441 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3443 # Run *our* eval that executes in the caller's context.
3446 # Turn off the one-time-dump stuff now.
3448 $onetimeDump = undef;
3449 $onetimedumpDepth = undef;
3451 elsif ( $term_pid == $$ ) {
3452 eval { # May run under miniperl, when not available...
3457 # XXX If this is the master pid, print a newline.
3460 } ## end while (($term || &setterm...
3462 =head3 POST-COMMAND PROCESSING
3464 After each command, we check to see if the command output was piped anywhere.
3465 If so, we go through the necessary code to unhook the pipe and go back to
3466 our standard filehandles for input and output.
3472 # At the end of every command:
3475 # Unhook the pipe mechanism now.
3476 if ( $pager =~ /^\|/ ) {
3478 # No error from the child.
3481 # we cannot warn here: the handle is missing --tchrist
3482 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
3484 # most of the $? crud was coping with broken cshisms
3485 # $? is explicitly set to 0, so this never runs.
3487 print SAVEOUT "Pager `$pager' failed: ";
3489 print SAVEOUT "shell returned -1\n";
3492 print SAVEOUT ( $? & 127 )
3493 ? " (SIG#" . ( $? & 127 ) . ")"
3494 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3497 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3501 # Reopen filehandle for our output (if we can) and
3502 # restore STDOUT (if we can).
3503 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3504 open( STDOUT, ">&SAVEOUT" )
3505 || &warn("Can't restore STDOUT");
3507 # Turn off pipe exception handler if necessary.
3508 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
3510 # Will stop ignoring SIGPIPE if done like nohup(1)
3511 # does SIGINT but Perl doesn't give us a choice.
3512 } ## end if ($pager =~ /^\|/)
3515 # Non-piped "pager". Just restore STDOUT.
3516 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3519 # Close filehandle pager was using, restore the normal one
3522 select($selected), $selected = "" unless $selected eq "";
3526 } ## end if ($piped)
3529 =head3 COMMAND LOOP TERMINATION
3531 When commands have finished executing, we come here. If the user closed the
3532 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3533 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3534 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3535 The interpreter will then execute the next line and then return control to us
3540 # No more commands? Quit.
3541 $fall_off_end = 1 unless defined $cmd; # Emulate `q' on EOF
3543 # Evaluate post-prompt commands.
3544 foreach $evalarg (@$post) {
3547 } # if ($single || $signal)
3549 # Put the user's globals back where you found them.
3550 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3554 # The following code may be executed now:
3559 C<sub> is called whenever a subroutine call happens in the program being
3560 debugged. The variable C<$DB::sub> contains the name of the subroutine
3563 The core function of this subroutine is to actually call the sub in the proper
3564 context, capturing its output. This of course causes C<DB::DB> to get called
3565 again, repeating until the subroutine ends and returns control to C<DB::sub>
3566 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3567 return value, and returns its captured copy of the return value as its own
3568 return value. The value then feeds back into the program being debugged as if
3569 C<DB::sub> hadn't been there at all.
3571 C<sub> does all the work of printing the subroutine entry and exit messages
3572 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3573 and also prints the return value if needed (for the C<r> command and if
3574 the 16 bit is set in C<$frame>).
3576 It also tracks the subroutine call depth by saving the current setting of
3577 C<$single> in the C<@stack> package global; if this exceeds the value in
3578 C<$deep>, C<sub> automatically turns on printing of the current depth by
3579 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
3580 of stop/don't stop on entry to subs set as it currently is set.
3582 =head3 C<caller()> support
3584 If C<caller()> is called from the package C<DB>, it provides some
3585 additional data, in the following order:
3591 The package name the sub was in
3593 =item * C<$filename>
3595 The filename it was defined in
3599 The line number it was defined on
3601 =item * C<$subroutine>
3603 The subroutine name; C<(eval)> if an C<eval>().
3607 1 if it has arguments, 0 if not
3609 =item * C<$wantarray>
3611 1 if array context, 0 if scalar context
3613 =item * C<$evaltext>
3615 The C<eval>() text, if any (undefined for C<eval BLOCK>)
3617 =item * C<$is_require>
3619 frame was created by a C<use> or C<require> statement
3623 pragma information; subject to change between versions
3627 pragma information; subject to change between versions
3629 =item * C<@DB::args>
3631 arguments with which the subroutine was invoked
3639 # lock ourselves under threads
3642 # Whether or not the autoloader was running, a scalar to put the
3643 # sub's return value in (if needed), and an array to put the sub's
3644 # return value in (if needed).
3645 my ( $al, $ret, @ret ) = "";
3646 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3647 print "creating new thread\n";
3650 # If the last ten characters are '::AUTOLOAD', note we've traced
3651 # into AUTOLOAD for $sub.
3652 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3653 $al = " for $$sub" if defined $$sub;
3656 # We stack the stack pointer and then increment it to protect us
3657 # from a situation that might unwind a whole bunch of call frames
3658 # at once. Localizing the stack pointer means that it will automatically
3659 # unwind the same amount when multiple stack frames are unwound.
3660 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3663 $#stack = $stack_depth;
3665 # Save current single-step setting.
3666 $stack[-1] = $single;
3668 # Turn off all flags except single-stepping.
3671 # If we've gotten really deeply recursed, turn on the flag that will
3672 # make us stop with the 'deep recursion' message.
3673 $single |= 4 if $stack_depth == $deep;
3675 # If frame messages are on ...
3677 $frame & 4 # Extended frame entry message
3679 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3681 # Why -1? But it works! :-(
3682 # Because print_trace will call add 1 to it and then call
3683 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3685 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3687 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3689 # standard frame entry message
3693 # Determine the sub's return type,and capture approppriately.
3696 # Called in array context. call sub and capture output.
3697 # DB::DB will recursively get control again if appropriate; we'll come
3698 # back here when the sub is finished.
3701 # Pop the single-step value back off the stack.
3702 $single |= $stack[ $stack_depth-- ];
3704 # Check for exit trace messages...
3706 $frame & 4 # Extended exit message
3708 print_lineinfo( ' ' x $stack_depth, "out " ),
3709 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3711 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3713 # Standard exit message
3717 # Print the return info if we need to.
3718 if ( $doret eq $stack_depth or $frame & 16 ) {
3720 # Turn off output record separator.
3722 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3724 # Indent if we're printing because of $frame tracing.
3725 print $fh ' ' x $stack_depth if $frame & 16;
3727 # Print the return value.
3728 print $fh "list context return from $sub:\n";
3729 dumpit( $fh, \@ret );
3731 # And don't print it again.
3733 } ## end if ($doret eq $stack_depth...
3734 # And we have to return the return value now.
3736 } ## end if (wantarray)
3740 if ( defined wantarray ) {
3742 # Save the value if it's wanted at all.
3747 # Void return, explicitly.
3752 # Pop the single-step value off the stack.
3753 $single |= $stack[ $stack_depth-- ];
3755 # If we're doing exit messages...
3757 $frame & 4 # Extended messsages
3759 print_lineinfo( ' ' x $stack_depth, "out " ),
3760 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3762 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3768 # If we are supposed to show the return value... same as before.
3769 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
3771 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3772 print $fh ( ' ' x $stack_depth ) if $frame & 16;
3775 ? "scalar context return from $sub: "
3776 : "void context return from $sub\n"
3778 dumpit( $fh, $ret ) if defined wantarray;
3780 } ## end if ($doret eq $stack_depth...
3782 # Return the appropriate scalar value.
3784 } ## end else [ if (wantarray)
3789 # lock ourselves under threads
3792 # Whether or not the autoloader was running, a scalar to put the
3793 # sub's return value in (if needed), and an array to put the sub's
3794 # return value in (if needed).
3795 my ( $al, $ret, @ret ) = "";
3796 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3797 print "creating new thread\n";
3800 # If the last ten characters are C'::AUTOLOAD', note we've traced
3801 # into AUTOLOAD for $sub.
3802 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3806 # We stack the stack pointer and then increment it to protect us
3807 # from a situation that might unwind a whole bunch of call frames
3808 # at once. Localizing the stack pointer means that it will automatically
3809 # unwind the same amount when multiple stack frames are unwound.
3810 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3813 $#stack = $stack_depth;
3815 # Save current single-step setting.
3816 $stack[-1] = $single;
3818 # Turn off all flags except single-stepping.
3821 # If we've gotten really deeply recursed, turn on the flag that will
3822 # make us stop with the 'deep recursion' message.
3823 $single |= 4 if $stack_depth == $deep;
3825 # If frame messages are on ...
3827 $frame & 4 # Extended frame entry message
3829 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3831 # Why -1? But it works! :-(
3832 # Because print_trace will call add 1 to it and then call
3833 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3835 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3837 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3839 # standard frame entry message
3843 # Pop the single-step value back off the stack.
3844 $single |= $stack[ $stack_depth-- ];
3846 # call the original lvalue sub.
3850 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
3852 In Perl 5.8.0, there was a major realignment of the commands and what they did,
3853 Most of the changes were to systematize the command structure and to eliminate
3854 commands that threw away user input without checking.
3856 The following sections describe the code added to make it easy to support
3857 multiple command sets with conflicting command names. This section is a start
3858 at unifying all command processing to make it simpler to develop commands.
3860 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
3861 number, and C<$dbline> (the current line) as arguments.
3863 Support functions in this section which have multiple modes of failure C<die>
3864 on error; the rest simply return a false value.
3866 The user-interface functions (all of the C<cmd_*> functions) just output
3871 The C<%set> hash defines the mapping from command letter to subroutine
3874 C<%set> is a two-level hash, indexed by set name and then by command name.
3875 Note that trying to set the CommandSet to C<foobar> simply results in the
3876 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
3885 'A' => 'pre580_null',
3887 'B' => 'pre580_null',
3888 'd' => 'pre580_null',
3891 'M' => 'pre580_null',
3893 'o' => 'pre580_null',
3899 '<' => 'pre590_prepost',
3900 '<<' => 'pre590_prepost',
3901 '>' => 'pre590_prepost',
3902 '>>' => 'pre590_prepost',
3903 '{' => 'pre590_prepost',
3904 '{{' => 'pre590_prepost',
3908 =head2 C<cmd_wrapper()> (API)
3910 C<cmd_wrapper()> allows the debugger to switch command sets
3911 depending on the value of the C<CommandSet> option.
3913 It tries to look up the command in the C<%set> package-level I<lexical>
3914 (which means external entities can't fiddle with it) and create the name of
3915 the sub to call based on the value found in the hash (if it's there). I<All>
3916 of the commands to be handled in a set have to be added to C<%set>; if they
3917 aren't found, the 5.8.0 equivalent is called (if there is one).
3919 This code uses symbolic references.
3926 my $dblineno = shift;
3928 # Assemble the command subroutine's name by looking up the
3929 # command set and command name in %set. If we can't find it,
3930 # default to the older version of the command.
3932 . ( $set{$CommandSet}{$cmd}
3933 || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) );
3935 # Call the command subroutine, call it by name.
3936 return &$call( $cmd, $line, $dblineno );
3937 } ## end sub cmd_wrapper
3939 =head3 C<cmd_a> (command)
3941 The C<a> command handles pre-execution actions. These are associated with a
3942 particular line, so they're stored in C<%dbline>. We default to the current
3943 line if none is specified.
3949 my $line = shift || ''; # [.|line] expr
3952 # If it's dot (here), or not all digits, use the current line.
3953 $line =~ s/^(\.|(?:[^\d]))/$dbline/;
3955 # Should be a line number followed by an expression.
3956 if ( $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
3957 my ( $lineno, $expr ) = ( $1, $2 );
3959 # If we have an expression ...
3960 if ( length $expr ) {
3962 # ... but the line isn't breakable, complain.
3963 if ( $dbline[$lineno] == 0 ) {
3965 "Line $lineno($dbline[$lineno]) does not have an action?\n";
3969 # It's executable. Record that the line has an action.
3970 $had_breakpoints{$filename} |= 2;
3972 # Remove any action, temp breakpoint, etc.
3973 $dbline{$lineno} =~ s/\0[^\0]*//;
3975 # Add the action to the line.
3976 $dbline{$lineno} .= "\0" . action($expr);
3978 } ## end if (length $expr)
3979 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
3984 "Adding an action requires an optional lineno and an expression\n"
3989 =head3 C<cmd_A> (command)
3991 Delete actions. Similar to above, except the delete code is in a separate
3992 subroutine, C<delete_action>.
3998 my $line = shift || '';
4002 $line =~ s/^\./$dbline/;
4004 # Call delete_action with a null param to delete them all.
4005 # The '1' forces the eval to be true. It'll be false only
4006 # if delete_action blows up for some reason, in which case
4007 # we print $@ and get out.
4008 if ( $line eq '*' ) {
4009 eval { &delete_action(); 1 } or print $OUT $@ and return;
4012 # There's a real line number. Pass it to delete_action.
4013 # Error trapping is as above.
4014 elsif ( $line =~ /^(\S.*)/ ) {
4015 eval { &delete_action($1); 1 } or print $OUT $@ and return;
4018 # Swing and a miss. Bad syntax.
4021 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4025 =head3 C<delete_action> (API)
4027 C<delete_action> accepts either a line number or C<undef>. If a line number
4028 is specified, we check for the line being executable (if it's not, it
4029 couldn't have had an action). If it is, we just take the action off (this
4030 will get any kind of an action, including breakpoints).
4036 if ( defined($i) ) {
4039 die "Line $i has no action .\n" if $dbline[$i] == 0;
4041 # Nuke whatever's there.
4042 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4043 delete $dbline{$i} if $dbline{$i} eq '';
4046 print $OUT "Deleting all actions...\n";
4047 for my $file ( keys %had_breakpoints ) {
4048 local *dbline = $main::{ '_<' . $file };
4051 for ( $i = 1 ; $i <= $max ; $i++ ) {
4052 if ( defined $dbline{$i} ) {
4053 $dbline{$i} =~ s/\0[^\0]*//;
4054 delete $dbline{$i} if $dbline{$i} eq '';
4056 unless ( $had_breakpoints{$file} &= ~2 ) {
4057 delete $had_breakpoints{$file};
4059 } ## end for ($i = 1 ; $i <= $max...
4060 } ## end for my $file (keys %had_breakpoints)
4061 } ## end else [ if (defined($i))
4062 } ## end sub delete_action
4064 =head3 C<cmd_b> (command)
4066 Set breakpoints. Since breakpoints can be set in so many places, in so many
4067 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4068 we try to parse the command type, and then shuttle it off to an appropriate
4069 subroutine to actually do the work of setting the breakpoint in the right
4076 my $line = shift; # [.|line] [cond]
4079 # Make . the current line number if it's there..
4080 $line =~ s/^\./$dbline/;
4082 # No line number, no condition. Simple break on current line.
4083 if ( $line =~ /^\s*$/ ) {
4084 &cmd_b_line( $dbline, 1 );
4087 # Break on load for a file.
4088 elsif ( $line =~ /^load\b\s*(.*)/ ) {
4094 # b compile|postpone <some sub> [<condition>]
4095 # The interpreter actually traps this one for us; we just put the
4096 # necessary condition in the %postponed hash.
4097 elsif ( $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4099 # Capture the condition if there is one. Make it true if none.
4100 my $cond = length $3 ? $3 : '1';
4102 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
4103 # if it was 'compile'.
4104 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
4106 # De-Perl4-ify the name - ' separators to ::.
4107 $subname =~ s/\'/::/g;
4109 # Qualify it into the current package unless it's already qualified.
4110 $subname = "${'package'}::" . $subname unless $subname =~ /::/;
4112 # Add main if it starts with ::.
4113 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4115 # Save the break type for this sub.
4116 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
4117 } ## end elsif ($line =~ ...
4119 # b <sub name> [<condition>]
4120 elsif ( $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4124 $cond = length $2 ? $2 : '1';
4125 &cmd_b_sub( $subname, $cond );
4128 # b <line> [<condition>].
4129 elsif ( $line =~ /^(\d*)\s*(.*)/ ) {
4131 # Capture the line. If none, it's the current line.
4132 $line = $1 || $dbline;
4134 # If there's no condition, make it '1'.
4135 $cond = length $2 ? $2 : '1';
4138 &cmd_b_line( $line, $cond );
4141 # Line didn't make sense.
4143 print "confused by line($line)?\n";
4147 =head3 C<break_on_load> (API)
4149 We want to break when this file is loaded. Mark this file in the
4150 C<%break_on_load> hash, and note that it has a breakpoint in
4151 C<%had_breakpoints>.
4157 $break_on_load{$file} = 1;
4158 $had_breakpoints{$file} |= 1;
4161 =head3 C<report_break_on_load> (API)
4163 Gives us an array of filenames that are set to break on load. Note that
4164 only files with break-on-load are in here, so simply showing the keys
4169 sub report_break_on_load {
4170 sort keys %break_on_load;
4173 =head3 C<cmd_b_load> (command)
4175 We take the file passed in and try to find it in C<%INC> (which maps modules
4176 to files they came from). We mark those files for break-on-load via
4177 C<break_on_load> and then report that it was done.
4185 # This is a block because that way we can use a redo inside it
4186 # even without there being any looping structure at all outside it.
4189 # Save short name and full path if found.
4191 push @files, $::INC{$file} if $::INC{$file};
4193 # Tack on .pm and do it again unless there was a '.' in the name
4195 $file .= '.pm', redo unless $file =~ /\./;
4198 # Do the real work here.
4199 break_on_load($_) for @files;
4201 # All the files that have break-on-load breakpoints.
4202 @files = report_break_on_load;
4204 # Normalize for the purposes of our printing this.
4207 print $OUT "Will stop on load of `@files'.\n";
4208 } ## end sub cmd_b_load
4210 =head3 C<$filename_error> (API package global)
4212 Several of the functions we need to implement in the API need to work both
4213 on the current file and on other files. We don't want to duplicate code, so
4214 C<$filename_error> is used to contain the name of the file that's being
4215 worked on (if it's not the current one).
4217 We can now build functions in pairs: the basic function works on the current
4218 file, and uses C<$filename_error> as part of its error message. Since this is
4219 initialized to C<"">, no filename will appear when we are working on the
4222 The second function is a wrapper which does the following:
4228 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4232 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4236 Calls the first function.
4238 The first function works on the I<current> file (i.e., the one we changed to),
4239 and prints C<$filename_error> in the error message (the name of the other file)
4240 if it needs to. When the functions return, C<*dbline> is restored to point
4241 to the actual current file (the one we're executing in) and
4242 C<$filename_error> is restored to C<"">. This restores everything to
4243 the way it was before the second function was called at all.
4245 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4252 $filename_error = '';
4254 =head3 breakable_line(from, to) (API)
4256 The subroutine decides whether or not a line in the current file is breakable.
4257 It walks through C<@dbline> within the range of lines specified, looking for
4258 the first line that is breakable.
4260 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4261 first line I<after> C<$to> that's breakable, if there is one.
4263 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4264 first line I<before> C<$to> that's breakable, if there is one.
4268 sub breakable_line {
4270 my ( $from, $to ) = @_;
4272 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4275 # If there are at least 2 arguments, we're trying to search a range.
4278 # $delta is positive for a forward search, negative for a backward one.
4279 my $delta = $from < $to ? +1 : -1;
4281 # Keep us from running off the ends of the file.
4282 my $limit = $delta > 0 ? $#dbline : 1;
4284 # Clever test. If you're a mathematician, it's obvious why this
4285 # test works. If not:
4286 # If $delta is positive (going forward), $limit will be $#dbline.
4287 # If $to is less than $limit, ($limit - $to) will be positive, times
4288 # $delta of 1 (positive), so the result is > 0 and we should use $to
4289 # as the stopping point.
4291 # If $to is greater than $limit, ($limit - $to) is negative,
4292 # times $delta of 1 (positive), so the result is < 0 and we should
4293 # use $limit ($#dbline) as the stopping point.
4295 # If $delta is negative (going backward), $limit will be 1.
4296 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4297 # (negative) so the result is > 0, and we use $to as the stopping
4300 # If $to is less than zero, ($limit - $to) will be positive,
4301 # times $delta of -1 (negative), so the result is not > 0, and
4302 # we use $limit (1) as the stopping point.
4304 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4305 # (negative), still giving zero; the result is not > 0, and
4306 # we use $limit (1) as the stopping point.
4308 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4309 # (negative), giving a positive (>0) value, so we'll set $limit to
4312 $limit = $to if ( $limit - $to ) * $delta > 0;
4314 # The real search loop.
4315 # $i starts at $from (the point we want to start searching from).
4316 # We move through @dbline in the appropriate direction (determined
4317 # by $delta: either -1 (back) or +1 (ahead).
4318 # We stay in as long as we haven't hit an executable line
4319 # ($dbline[$i] == 0 means not executable) and we haven't reached
4320 # the limit yet (test similar to the above).
4321 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4323 } ## end if (@_ >= 2)
4325 # If $i points to a line that is executable, return that.
4326 return $i unless $dbline[$i] == 0;
4328 # Format the message and print it: no breakable lines in range.
4329 my ( $pl, $upto ) = ( '', '' );
4330 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4332 # If there's a filename in filename_error, we'll see it.
4334 die "Line$pl $from$upto$filename_error not breakable\n";
4335 } ## end sub breakable_line
4337 =head3 breakable_line_in_filename(file, from, to) (API)
4339 Like C<breakable_line>, but look in another file.
4343 sub breakable_line_in_filename {
4345 # Capture the file name.
4348 # Swap the magic line array over there temporarily.
4349 local *dbline = $main::{ '_<' . $f };
4351 # If there's an error, it's in this other file.
4352 local $filename_error = " of `$f'";
4354 # Find the breakable line.
4357 # *dbline and $filename_error get restored when this block ends.
4359 } ## end sub breakable_line_in_filename
4361 =head3 break_on_line(lineno, [condition]) (API)
4363 Adds a breakpoint with the specified condition (or 1 if no condition was
4364 specified) to the specified line. Dies if it can't.
4369 my ( $i, $cond ) = @_;
4371 # Always true if no condition supplied.
4372 $cond = 1 unless @_ >= 2;
4378 # Woops, not a breakable line. $filename_error allows us to say
4379 # if it was in a different file.
4380 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4382 # Mark this file as having breakpoints in it.
4383 $had_breakpoints{$filename} |= 1;
4385 # If there is an action or condition here already ...
4386 if ( $dbline{$i} ) {
4388 # ... swap this condition for the existing one.
4389 $dbline{$i} =~ s/^[^\0]*/$cond/;
4393 # Nothing here - just add the condition.
4394 $dbline{$i} = $cond;
4396 } ## end sub break_on_line
4398 =head3 cmd_b_line(line, [condition]) (command)
4400 Wrapper for C<break_on_line>. Prints the failure message if it
4406 eval { break_on_line(@_); 1 } or do {
4408 print $OUT $@ and return;
4410 } ## end sub cmd_b_line
4412 =head3 break_on_filename_line(file, line, [condition]) (API)
4414 Switches to the file specified and then calls C<break_on_line> to set
4419 sub break_on_filename_line {
4420 my ( $f, $i, $cond ) = @_;
4422 # Always true if condition left off.
4423 $cond = 1 unless @_ >= 3;
4425 # Switch the magical hash temporarily.
4426 local *dbline = $main::{ '_<' . $f };
4428 # Localize the variables that break_on_line uses to make its message.
4429 local $filename_error = " of `$f'";
4430 local $filename = $f;
4432 # Add the breakpoint.
4433 break_on_line( $i, $cond );
4434 } ## end sub break_on_filename_line
4436 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4438 Switch to another file, search the range of lines specified for an
4439 executable one, and put a breakpoint on the first one you find.
4443 sub break_on_filename_line_range {
4444 my ( $f, $from, $to, $cond ) = @_;
4446 # Find a breakable line if there is one.
4447 my $i = breakable_line_in_filename( $f, $from, $to );
4449 # Always true if missing.
4450 $cond = 1 unless @_ >= 3;
4452 # Add the breakpoint.
4453 break_on_filename_line( $f, $i, $cond );
4454 } ## end sub break_on_filename_line_range
4456 =head3 subroutine_filename_lines(subname, [condition]) (API)
4458 Search for a subroutine within a given file. The condition is ignored.
4459 Uses C<find_sub> to locate the desired subroutine.
4463 sub subroutine_filename_lines {
4464 my ( $subname, $cond ) = @_;
4466 # Returned value from find_sub() is fullpathname:startline-endline.
4467 # The match creates the list (fullpathname, start, end). Falling off
4468 # the end of the subroutine returns this implicitly.
4469 find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/;
4470 } ## end sub subroutine_filename_lines
4472 =head3 break_subroutine(subname) (API)
4474 Places a break on the first line possible in the specified subroutine. Uses
4475 C<subroutine_filename_lines> to find the subroutine, and
4476 C<break_on_filename_line_range> to place the break.
4480 sub break_subroutine {
4481 my $subname = shift;
4483 # Get filename, start, and end.
4484 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
4485 or die "Subroutine $subname not found.\n";
4487 # Null condition changes to '1' (always true).
4488 $cond = 1 unless @_ >= 2;
4490 # Put a break the first place possible in the range of lines
4491 # that make up this subroutine.
4492 break_on_filename_line_range( $file, $s, $e, @_ );
4493 } ## end sub break_subroutine
4495 =head3 cmd_b_sub(subname, [condition]) (command)
4497 We take the incoming subroutine name and fully-qualify it as best we can.
4501 =item 1. If it's already fully-qualified, leave it alone.
4503 =item 2. Try putting it in the current package.
4505 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
4507 =item 4. If it starts with '::', put it in 'main::'.
4511 After all this cleanup, we call C<break_subroutine> to try to set the
4517 my ( $subname, $cond ) = @_;
4519 # Add always-true condition if we have none.
4520 $cond = 1 unless @_ >= 2;
4522 # If the subname isn't a code reference, qualify it so that
4523 # break_subroutine() will work right.
4524 unless ( ref $subname eq 'CODE' ) {
4527 $subname =~ s/\'/::/g;
4530 # Put it in this package unless it's already qualified.
4531 $subname = "${'package'}::" . $subname
4532 unless $subname =~ /::/;
4534 # Requalify it into CORE::GLOBAL if qualifying it into this
4535 # package resulted in its not being defined, but only do so
4536 # if it really is in CORE::GLOBAL.
4537 $subname = "CORE::GLOBAL::$s"
4538 if not defined &$subname
4540 and defined &{"CORE::GLOBAL::$s"};
4542 # Put it in package 'main' if it has a leading ::.
4543 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4545 } ## end unless (ref $subname eq 'CODE')
4547 # Try to set the breakpoint.
4548 eval { break_subroutine( $subname, $cond ); 1 } or do {
4550 print $OUT $@ and return;
4552 } ## end sub cmd_b_sub
4554 =head3 C<cmd_B> - delete breakpoint(s) (command)
4556 The command mostly parses the command line and tries to turn the argument
4557 into a line spec. If it can't, it uses the current line. It then calls
4558 C<delete_breakpoint> to actually do the work.
4560 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
4561 thereby deleting all the breakpoints.
4568 # No line spec? Use dbline.
4569 # If there is one, use it if it's non-zero, or wipe it out if it is.
4570 my $line = ( $_[0] =~ /^\./ ) ? $dbline : shift || '';
4573 # If the line was dot, make the line the current one.
4574 $line =~ s/^\./$dbline/;
4576 # If it's * we're deleting all the breakpoints.
4577 if ( $line eq '*' ) {
4578 eval { &delete_breakpoint(); 1 } or print $OUT $@ and return;
4581 # If there is a line spec, delete the breakpoint on that line.
4582 elsif ( $line =~ /^(\S.*)/ ) {
4583 eval { &delete_breakpoint( $line || $dbline ); 1 } or do {
4585 print $OUT $@ and return;
4587 } ## end elsif ($line =~ /^(\S.*)/)
4592 "Deleting a breakpoint requires a line number, or '*' for all\n"
4597 =head3 delete_breakpoint([line]) (API)
4599 This actually does the work of deleting either a single breakpoint, or all
4602 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
4603 just drop out with a message saying so. If it is, we remove the condition
4604 part of the 'condition\0action' that says there's a breakpoint here. If,
4605 after we've done that, there's nothing left, we delete the corresponding
4606 line in C<%dbline> to signal that no action needs to be taken for this line.
4608 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
4609 which lists all currently-loaded files which have breakpoints. We then look
4610 at each line in each of these files, temporarily switching the C<%dbline>
4611 and C<@dbline> structures to point to the files in question, and do what
4612 we did in the single line case: delete the condition in C<@dbline>, and
4613 delete the key in C<%dbline> if nothing's left.
4615 We then wholesale delete C<%postponed>, C<%postponed_file>, and
4616 C<%break_on_load>, because these structures contain breakpoints for files
4617 and code that haven't been loaded yet. We can just kill these off because there
4618 are no magical debugger structures associated with them.
4622 sub delete_breakpoint {
4625 # If we got a line, delete just that one.
4626 if ( defined($i) ) {
4628 # Woops. This line wasn't breakable at all.
4629 die "Line $i not breakable.\n" if $dbline[$i] == 0;
4631 # Kill the condition, but leave any action.
4632 $dbline{$i} =~ s/^[^\0]*//;
4634 # Remove the entry entirely if there's no action left.
4635 delete $dbline{$i} if $dbline{$i} eq '';
4638 # No line; delete them all.
4640 print $OUT "Deleting all breakpoints...\n";
4642 # %had_breakpoints lists every file that had at least one
4644 for my $file ( keys %had_breakpoints ) {
4646 # Switch to the desired file temporarily.
4647 local *dbline = $main::{ '_<' . $file };
4652 # For all lines in this file ...
4653 for ( $i = 1 ; $i <= $max ; $i++ ) {
4655 # If there's a breakpoint or action on this line ...
4656 if ( defined $dbline{$i} ) {
4658 # ... remove the breakpoint.
4659 $dbline{$i} =~ s/^[^\0]+//;
4660 if ( $dbline{$i} =~ s/^\0?$// ) {
4662 # Remove the entry altogether if no action is there.
4665 } ## end if (defined $dbline{$i...
4666 } ## end for ($i = 1 ; $i <= $max...
4668 # If, after we turn off the "there were breakpoints in this file"
4669 # bit, the entry in %had_breakpoints for this file is zero,
4670 # we should remove this file from the hash.
4671 if ( not $had_breakpoints{$file} &= ~1 ) {
4672 delete $had_breakpoints{$file};
4674 } ## end for my $file (keys %had_breakpoints)
4676 # Kill off all the other breakpoints that are waiting for files that
4677 # haven't been loaded yet.
4679 undef %postponed_file;
4680 undef %break_on_load;
4681 } ## end else [ if (defined($i))
4682 } ## end sub delete_breakpoint
4684 =head3 cmd_stop (command)
4686 This is meant to be part of the new command API, but it isn't called or used
4687 anywhere else in the debugger. XXX It is probably meant for use in development
4692 sub cmd_stop { # As on ^C, but not signal-safy.
4696 =head3 C<cmd_e> - threads
4698 Display the current thread id:
4702 This could be how (when implemented) to send commands to this thread id (e cmd)
4703 or that thread id (e tid cmd).
4710 unless (exists($INC{'threads.pm'})) {
4711 print "threads not loaded($ENV{PERL5DB_THREADED})
4712 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4714 my $tid = threads->tid;
4715 print "thread id: $tid\n";
4719 =head3 C<cmd_E> - list of thread ids
4721 Display the list of available thread ids:
4725 This could be used (when implemented) to send commands to all threads (E cmd).
4732 unless (exists($INC{'threads.pm'})) {
4733 print "threads not loaded($ENV{PERL5DB_THREADED})
4734 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4736 my $tid = threads->tid;
4737 print "thread ids: ".join(', ',
4738 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
4743 =head3 C<cmd_h> - help command (command)
4745 Does the work of either
4751 Showing all the debugger help
4755 Showing help for a specific command
4764 # If we have no operand, assume null.
4765 my $line = shift || '';
4767 # 'h h'. Print the long-format help.
4768 if ( $line =~ /^h\s*/ ) {
4772 # 'h <something>'. Search for the command and print only its help.
4773 elsif ( $line =~ /^(\S.*)$/ ) {
4775 # support long commands; otherwise bogus errors
4776 # happen when you ask for h on <CR> for example
4777 my $asked = $1; # the command requested
4778 # (for proper error message)
4780 my $qasked = quotemeta($asked); # for searching; we don't
4781 # want to use it as a pattern.
4782 # XXX: finds CR but not <CR>
4784 # Search the help string for the command.
4786 $help =~ /^ # Start of a line
4788 (?:[IB]<) # Optional markup
4789 $qasked # The requested command
4794 # It's there; pull it out and print it.
4798 (?:[IB]<) # Optional markup
4799 $qasked # The command
4800 ([\s\S]*?) # Description line(s)
4801 \n) # End of last description line
4802 (?!\s) # Next line not starting with
4811 # Not found; not a debugger command.
4813 print_help("B<$asked> is not a debugger command.\n");
4815 } ## end elsif ($line =~ /^(\S.*)$/)
4817 # 'h' - print the summary help.
4819 print_help($summary);
4823 =head3 C<cmd_i> - inheritance display
4825 Display the (nested) parentage of the module or object given.
4832 eval { require Class::ISA };
4834 &warn( $@ =~ /locate/
4835 ? "Class::ISA module not found - please install\n"
4840 foreach my $isa ( split( /\s+/, $line ) ) {
4846 map { # snaffled unceremoniously from Class::ISA
4849 defined( ${"$_\::VERSION"} )
4850 ? ' ' . ${"$_\::VERSION"}
4852 } Class::ISA::self_and_super_path(ref($isa) || $isa)
4859 =head3 C<cmd_l> - list lines (command)
4861 Most of the command is taken up with transforming all the different line
4862 specification syntaxes into 'start-stop'. After that is done, the command
4863 runs a loop over C<@dbline> for the specified range of lines. It handles
4864 the printing of each line and any markers (C<==E<gt>> for current line,
4865 C<b> for break on this line, C<a> for action on this line, C<:> for this
4868 We save the last line listed in the C<$start> global for further listing
4874 my $current_line = $line;
4878 # If this is '-something', delete any spaces after the dash.
4879 $line =~ s/^-\s*$/-/;
4881 # If the line is '$something', assume this is a scalar containing a
4883 if ( $line =~ /^(\$.*)/s ) {
4885 # Set up for DB::eval() - evaluate in *user* context.
4890 # Ooops. Bad scalar.
4891 print( $OUT "Error: $@\n" ), next CMD if $@;
4893 # Good scalar. If it's a reference, find what it points to.
4895 print( $OUT "Interpreted as: $1 $s\n" );
4898 # Call self recursively to really do the command.
4900 } ## end if ($line =~ /^(\$.*)/s)
4902 # l name. Try to find a sub by that name.
4903 elsif ( $line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s ) {
4904 my $s = $subname = $1;
4907 $subname =~ s/\'/::/;
4909 # Put it in this package unless it starts with ::.
4910 $subname = $package . "::" . $subname unless $subname =~ /::/;
4912 # Put it in CORE::GLOBAL if t doesn't start with :: and
4913 # it doesn't live in this package and it lives in CORE::GLOBAL.
4914 $subname = "CORE::GLOBAL::$s"
4915 if not defined &$subname
4917 and defined &{"CORE::GLOBAL::$s"};
4919 # Put leading '::' names into 'main::'.
4920 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4922 # Get name:start-stop from find_sub, and break this up at
4924 @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
4926 # Pull off start-stop.
4927 $subrange = pop @pieces;
4929 # If the name contained colons, the split broke it up.
4930 # Put it back together.
4931 $file = join( ':', @pieces );
4933 # If we're not in that file, switch over to it.
4934 if ( $file ne $filename ) {
4935 print $OUT "Switching to file '$file'.\n"
4936 unless $slave_editor;
4938 # Switch debugger's magic structures.
4939 *dbline = $main::{ '_<' . $file };
4942 } ## end if ($file ne $filename)
4944 # Subrange is 'start-stop'. If this is less than a window full,
4945 # swap it to 'start+', which will list a window from the start point.
4947 if ( eval($subrange) < -$window ) {
4948 $subrange =~ s/-.*/+/;
4951 # Call self recursively to list the range.
4953 &cmd_l( 'l', $subrange );
4954 } ## end if ($subrange)
4958 print $OUT "Subroutine $subname not found.\n";
4960 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
4963 elsif ( $line =~ /^\s*$/ ) {
4965 # Compute new range to list.
4966 $incr = $window - 1;
4967 $line = $start . '-' . ( $start + $incr );
4970 &cmd_l( 'l', $line );
4973 # l [start]+number_of_lines
4974 elsif ( $line =~ /^(\d*)\+(\d*)$/ ) {
4976 # Don't reset start for 'l +nnn'.
4979 # Increment for list. Use window size if not specified.
4980 # (Allows 'l +' to work.)
4982 $incr = $window - 1 unless $incr;
4984 # Create a line range we'll understand, and recurse to do it.
4985 $line = $start . '-' . ( $start + $incr );
4986 &cmd_l( 'l', $line );
4987 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
4989 # l start-stop or l start,stop
4990 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) {
4992 # Determine end point; use end of file if not specified.
4993 $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 );
4995 # Go on to the end, and then stop.
4996 $end = $max if $end > $max;
4998 # Determine start line.
5000 $i = $line if $i eq '.';
5004 # If we're running under a slave editor, force it to show the lines.
5005 if ($slave_editor) {
5006 print $OUT "\032\032$filename:$i:0\n";
5010 # We're doing it ourselves. We want to show the line and special
5012 # - the current line in execution
5013 # - whether a line is breakable or not
5014 # - whether a line has a break or not
5015 # - whether a line has an action or not
5017 for ( ; $i <= $end ; $i++ ) {
5019 # Check for breakpoints and actions.
5020 my ( $stop, $action );
5021 ( $stop, $action ) = split( /\0/, $dbline{$i} )
5024 # ==> if this is the current line in execution,
5025 # : if it's breakable.
5027 ( $i == $current_line and $filename eq $filename_ini )
5029 : ( $dbline[$i] + 0 ? ':' : ' ' );
5031 # Add break and action indicators.
5032 $arrow .= 'b' if $stop;
5033 $arrow .= 'a' if $action;
5036 print $OUT "$i$arrow\t", $dbline[$i];
5038 # Move on to the next line. Drop out on an interrupt.
5039 $i++, last if $signal;
5040 } ## end for (; $i <= $end ; $i++)
5042 # Line the prompt up; print a newline if the last line listed
5043 # didn't have a newline.
5044 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/;
5045 } ## end else [ if ($slave_editor)
5047 # Save the point we last listed to in case another relative 'l'
5048 # command is desired. Don't let it run off the end.
5050 $start = $max if $start > $max;
5051 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
5054 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5056 To list breakpoints, the command has to look determine where all of them are
5057 first. It starts a C<%had_breakpoints>, which tells us what all files have
5058 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5059 magic source and breakpoint data structures) to the file, and then look
5060 through C<%dbline> for lines with breakpoints and/or actions, listing them
5061 out. We look through C<%postponed> not-yet-compiled subroutines that have
5062 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5063 that have breakpoints.
5065 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5072 # If no argument, list everything. Pre-5.8.0 version always lists
5074 my $arg = shift || 'abw';
5075 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
5077 # See what is wanted.
5078 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0;
5079 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0;
5080 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0;
5082 # Breaks and actions are found together, so we look in the same place
5084 if ( $break_wanted or $action_wanted ) {
5086 # Look in all the files with breakpoints...
5087 for my $file ( keys %had_breakpoints ) {
5089 # Temporary switch to this file.
5090 local *dbline = $main::{ '_<' . $file };
5092 # Set up to look through the whole file.
5094 my $was; # Flag: did we print something
5097 # For each line in the file ...
5098 for ( $i = 1 ; $i <= $max ; $i++ ) {
5100 # We've got something on this line.
5101 if ( defined $dbline{$i} ) {
5103 # Print the header if we haven't.
5104 print $OUT "$file:\n" unless $was++;
5107 print $OUT " $i:\t", $dbline[$i];
5109 # Pull out the condition and the action.
5110 ( $stop, $action ) = split( /\0/, $dbline{$i} );
5112 # Print the break if there is one and it's wanted.
5113 print $OUT " break if (", $stop, ")\n"
5117 # Print the action if there is one and it's wanted.
5118 print $OUT " action: ", $action, "\n"
5122 # Quit if the user hit interrupt.
5124 } ## end if (defined $dbline{$i...
5125 } ## end for ($i = 1 ; $i <= $max...
5126 } ## end for my $file (keys %had_breakpoints)
5127 } ## end if ($break_wanted or $action_wanted)
5129 # Look for breaks in not-yet-compiled subs:
5130 if ( %postponed and $break_wanted ) {
5131 print $OUT "Postponed breakpoints in subroutines:\n";
5133 for $subname ( keys %postponed ) {
5134 print $OUT " $subname\t$postponed{$subname}\n";
5137 } ## end if (%postponed and $break_wanted)
5139 # Find files that have not-yet-loaded breaks:
5140 my @have = map { # Combined keys
5141 keys %{ $postponed_file{$_} }
5142 } keys %postponed_file;
5144 # If there are any, list them.
5145 if ( @have and ( $break_wanted or $action_wanted ) ) {
5146 print $OUT "Postponed breakpoints in files:\n";
5147 my ( $file, $line );
5149 for $file ( keys %postponed_file ) {
5150 my $db = $postponed_file{$file};
5151 print $OUT " $file:\n";
5152 for $line ( sort { $a <=> $b } keys %$db ) {
5153 print $OUT " $line:\n";
5154 my ( $stop, $action ) = split( /\0/, $$db{$line} );
5155 print $OUT " break if (", $stop, ")\n"
5158 print $OUT " action: ", $action, "\n"
5162 } ## end for $line (sort { $a <=>...
5164 } ## end for $file (keys %postponed_file)
5165 } ## end if (@have and ($break_wanted...
5166 if ( %break_on_load and $break_wanted ) {
5167 print $OUT "Breakpoints on load:\n";
5169 for $file ( keys %break_on_load ) {
5170 print $OUT " $file\n";
5173 } ## end if (%break_on_load and...
5174 if ($watch_wanted) {
5176 print $OUT "Watch-expressions:\n" if @to_watch;
5177 for my $expr (@to_watch) {
5178 print $OUT " $expr\n";
5181 } ## end if ($trace & 2)
5182 } ## end if ($watch_wanted)
5185 =head3 C<cmd_M> - list modules (command)
5187 Just call C<list_modules>.
5195 =head3 C<cmd_o> - options (command)
5197 If this is just C<o> by itself, we list the current settings via
5198 C<dump_option>. If there's a nonblank value following it, we pass that on to
5199 C<parse_options> for processing.
5205 my $opt = shift || ''; # opt[=val]
5207 # Nonblank. Try to parse and process.
5208 if ( $opt =~ /^(\S.*)/ ) {
5212 # Blank. List the current option settings.
5220 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5222 Advises the user that the O command has been renamed.
5227 print $OUT "The old O command is now the o command.\n"; # hint
5228 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5229 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5232 =head3 C<cmd_v> - view window (command)
5234 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5235 move back a few lines to list the selected line in context. Uses C<cmd_l>
5236 to do the actual listing after figuring out the range of line to request.
5244 # Extract the line to list around. (Astute readers will have noted that
5245 # this pattern will match whether or not a numeric line is specified,
5246 # which means that we'll always enter this loop (though a non-numeric
5247 # argument results in no action at all)).
5248 if ( $line =~ /^(\d*)$/ ) {
5250 # Total number of lines to list (a windowful).
5251 $incr = $window - 1;
5253 # Set the start to the argument given (if there was one).
5256 # Back up by the context amount.
5259 # Put together a linespec that cmd_l will like.
5260 $line = $start . '-' . ( $start + $incr );
5263 &cmd_l( 'l', $line );
5264 } ## end if ($line =~ /^(\d*)$/)
5267 =head3 C<cmd_w> - add a watch expression (command)
5269 The 5.8 version of this command adds a watch expression if one is specified;
5270 it does nothing if entered with no operands.
5272 We extract the expression, save it, evaluate it in the user's context, and
5273 save the value. We'll re-evaluate it each time the debugger passes a line,
5274 and will stop (see the code at the top of the command loop) if the value
5275 of any of the expressions changes.
5282 # Null expression if no arguments.
5283 my $expr = shift || '';
5285 # If expression is not null ...
5286 if ( $expr =~ /^(\S.*)/ ) {
5289 push @to_watch, $expr;
5291 # Parameterize DB::eval and call it to get the expression's value
5292 # in the user's context. This version can handle expressions which
5293 # return a list value.
5295 my ($val) = join( ' ', &eval );
5296 $val = ( defined $val ) ? "'$val'" : 'undef';
5298 # Save the current value of the expression.
5299 push @old_watch, $val;
5301 # We are now watching expressions.
5303 } ## end if ($expr =~ /^(\S.*)/)
5305 # You have to give one to get one.
5307 print $OUT "Adding a watch-expression requires an expression\n"; # hint
5311 =head3 C<cmd_W> - delete watch expressions (command)
5313 This command accepts either a watch expression to be removed from the list
5314 of watch expressions, or C<*> to delete them all.
5316 If C<*> is specified, we simply empty the watch expression list and the
5317 watch expression value list. We also turn off the bit that says we've got
5320 If an expression (or partial expression) is specified, we pattern-match
5321 through the expressions and remove the ones that match. We also discard
5322 the corresponding values. If no watch expressions are left, we turn off
5323 the I<watching expressions> bit.
5329 my $expr = shift || '';
5332 if ( $expr eq '*' ) {
5337 print $OUT "Deleting all watch expressions ...\n";
5340 @to_watch = @old_watch = ();
5343 # Delete one of them.
5344 elsif ( $expr =~ /^(\S.*)/ ) {
5346 # Where we are in the list.
5349 # For each expression ...
5350 foreach (@to_watch) {
5351 my $val = $to_watch[$i_cnt];
5353 # Does this one match the command argument?
5354 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
5355 # Yes. Turn it off, and its value too.
5356 splice( @to_watch, $i_cnt, 1 );
5357 splice( @old_watch, $i_cnt, 1 );
5360 } ## end foreach (@to_watch)
5362 # We don't bother to turn watching off because
5363 # a) we don't want to stop calling watchfunction() it it exists
5364 # b) foreach over a null list doesn't do anything anyway
5366 } ## end elsif ($expr =~ /^(\S.*)/)
5368 # No command arguments entered.
5371 "Deleting a watch-expression requires an expression, or '*' for all\n"
5376 ### END of the API section
5378 =head1 SUPPORT ROUTINES
5380 These are general support routines that are used in a number of places
5381 throughout the debugger.
5385 save() saves the user's versions of globals that would mess us up in C<@saved>,
5386 and installs the versions we like better.
5392 # Save eval failure, command failure, extended OS error, output field
5393 # separator, input record separator, output record separator and
5394 # the warning setting.
5395 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
5397 $, = ""; # output field separator is null string
5398 $/ = "\n"; # input record separator is newline
5399 $\ = ""; # output record separator is null string
5400 $^W = 0; # warnings are off
5403 =head2 C<print_lineinfo> - show where we are now
5405 print_lineinfo prints whatever it is that it is handed; it prints it to the
5406 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5407 us to feed line information to a slave editor without messing up the
5412 sub print_lineinfo {
5414 # Make the terminal sensible if we're not the primary debugger.
5415 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5419 } ## end sub print_lineinfo
5421 =head2 C<postponed_sub>
5423 Handles setting postponed breakpoints in subroutines once they're compiled.
5424 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5425 range for the subroutine, then mark the file as having a breakpoint,
5426 temporarily switch the C<*dbline> glob over to the source file, and then
5427 search the given range of lines to find a breakable line. If we find one,
5428 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
5432 # The following takes its argument via $evalarg to preserve current @_
5436 # Get the subroutine name.
5437 my $subname = shift;
5439 # If this is a 'break +<n> if <condition>' ...
5440 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
5442 # If there's no offset, use '+0'.
5443 my $offset = $1 || 0;
5445 # find_sub's value is 'fullpath-filename:start-stop'. It's
5446 # possible that the filename might have colons in it too.
5447 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
5450 # We got the start line. Add the offset '+<n>' from
5451 # $postponed{subname}.
5454 # Switch to the file this sub is in, temporarily.
5455 local *dbline = $main::{ '_<' . $file };
5457 # No warnings, please.
5458 local $^W = 0; # != 0 is magical below
5460 # This file's got a breakpoint in it.
5461 $had_breakpoints{$file} |= 1;
5463 # Last line in file.
5466 # Search forward until we hit a breakable line or get to
5467 # the end of the file.
5468 ++$i until $dbline[$i] != 0 or $i >= $max;
5470 # Copy the breakpoint in and delete it from %postponed.
5471 $dbline{$i} = delete $postponed{$subname};
5474 # find_sub didn't find the sub.
5477 print $OUT "Subroutine $subname not found.\n";
5480 } ## end if ($postponed{$subname...
5481 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
5483 #print $OUT "In postponed_sub for `$subname'.\n";
5484 } ## end sub postponed_sub
5488 Called after each required file is compiled, but before it is executed;
5489 also called if the name of a just-compiled subroutine is a key of
5490 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
5491 etc.) into the just-compiled code.
5493 If this is a C<require>'d file, the incoming parameter is the glob
5494 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
5496 If it's a subroutine, the incoming parameter is the subroutine name.
5502 # If there's a break, process it.
5503 if ($ImmediateStop) {
5505 # Right, we've stopped. Turn it off.
5508 # Enter the command loop when DB::DB gets called.
5512 # If this is a subroutine, let postponed_sub() deal with it.
5513 return &postponed_sub unless ref \$_[0] eq 'GLOB';
5515 # Not a subroutine. Deal with the file.
5516 local *dbline = shift;
5517 my $filename = $dbline;
5518 $filename =~ s/^_<//;
5520 $signal = 1, print $OUT "'$filename' loaded...\n"
5521 if $break_on_load{$filename};
5522 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
5524 # Do we have any breakpoints to put in this file?
5525 return unless $postponed_file{$filename};
5527 # Yes. Mark this file as having breakpoints.
5528 $had_breakpoints{$filename} |= 1;
5530 # "Cannot be done: unsufficient magic" - we can't just put the
5531 # breakpoints saved in %postponed_file into %dbline by assigning
5532 # the whole hash; we have to do it one item at a time for the
5533 # breakpoints to be set properly.
5534 #%dbline = %{$postponed_file{$filename}};
5536 # Set the breakpoints, one at a time.
5539 for $key ( keys %{ $postponed_file{$filename} } ) {
5541 # Stash the saved breakpoint into the current file's magic line array.
5542 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
5545 # This file's been compiled; discard the stored breakpoints.
5546 delete $postponed_file{$filename};
5548 } ## end sub postponed
5552 C<dumpit> is the debugger's wrapper around dumpvar.pl.
5554 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
5555 a reference to a variable (the thing to be dumped) as its input.
5557 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
5558 the currently-selected filehandle, thank you very much). The current
5559 values of the package globals C<$single> and C<$trace> are backed up in
5560 lexicals, and they are turned off (this keeps the debugger from trying
5561 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
5562 preserve its current value and it is set to zero to prevent entry/exit
5563 messages from printing, and C<$doret> is localized as well and set to -2 to
5564 prevent return values from being shown.
5566 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
5567 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
5568 installed version in C<@INC>, yours will be used instead. Possible security
5571 It then checks to see if the subroutine C<main::dumpValue> is now defined
5572 (it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
5573 localizes the globals necessary for things to be sane when C<main::dumpValue()>
5574 is called, and picks up the variable to be dumped from the parameter list.
5576 It checks the package global C<%options> to see if there's a C<dumpDepth>
5577 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
5578 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
5579 structure: -1 means dump everything.
5581 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
5584 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
5585 and we then return to the caller.
5591 # Save the current output filehandle and switch to the one
5592 # passed in as the first parameter.
5593 local ($savout) = select(shift);
5595 # Save current settings of $single and $trace, and then turn them off.
5596 my $osingle = $single;
5597 my $otrace = $trace;
5598 $single = $trace = 0;
5600 # XXX Okay, what do $frame and $doret do, again?
5604 # Load dumpvar.pl unless we've already got the sub we need from it.
5605 unless ( defined &main::dumpValue ) {
5606 do 'dumpvar.pl' or die $@;
5609 # If the load succeeded (or we already had dumpvalue()), go ahead
5611 if ( defined &main::dumpValue ) {
5616 my $maxdepth = shift || $option{dumpDepth};
5617 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
5618 &main::dumpValue( $v, $maxdepth );
5619 } ## end if (defined &main::dumpValue)
5621 # Oops, couldn't load dumpvar.pl.
5624 print $OUT "dumpvar.pl not available.\n";
5627 # Reset $single and $trace to their old values.
5631 # Restore the old filehandle.
5635 =head2 C<print_trace>
5637 C<print_trace>'s job is to print a stack trace. It does this via the
5638 C<dump_trace> routine, which actually does all the ferreting-out of the
5639 stack trace data. C<print_trace> takes care of formatting it nicely and
5640 printing it to the proper filehandle.
5648 The filehandle to print to.
5652 How many frames to skip before starting trace.
5656 How many frames to print.
5660 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
5664 The original comment below seems to be noting that the traceback may not be
5665 correct if this routine is called in a tied method.
5669 # Tied method do not create a context, so may get wrong message:
5675 # If this is going to a slave editor, but we're not the primary
5676 # debugger, reset it first.
5678 if $fh eq $LINEINFO # slave editor
5679 and $LINEINFO eq $OUT # normal output
5680 and $term_pid != $$; # not the primary
5682 # Collect the actual trace information to be formatted.
5683 # This is an array of hashes of subroutine call info.
5684 my @sub = dump_trace( $_[0] + 1, $_[1] );
5686 # Grab the "short report" flag from @_.
5687 my $short = $_[2]; # Print short report, next one for sub name
5689 # Run through the traceback info, format it, and print it.
5691 for ( $i = 0 ; $i <= $#sub ; $i++ ) {
5693 # Drop out if the user has lost interest and hit control-C.
5696 # Set the separator so arrys print nice.
5699 # Grab and stringify the arguments if they are there.
5701 defined $sub[$i]{args}
5702 ? "(@{ $sub[$i]{args} })"
5705 # Shorten them up if $maxtrace says they're too long.
5706 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
5707 if length $args > $maxtrace;
5709 # Get the file name.
5710 my $file = $sub[$i]{file};
5712 # Put in a filename header if short is off.
5713 $file = $file eq '-e' ? $file : "file `$file'" unless $short;
5715 # Get the actual sub's name, and shorten to $maxtrace's requirement.
5717 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
5719 # Short report uses trimmed file and sub names.
5721 my $sub = @_ >= 4 ? $_[3] : $s;
5722 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
5723 } ## end if ($short)
5725 # Non-short report includes full names.
5727 print $fh "$sub[$i]{context} = $s$args"
5728 . " called from $file"
5729 . " line $sub[$i]{line}\n";
5731 } ## end for ($i = 0 ; $i <= $#sub...
5732 } ## end sub print_trace
5734 =head2 dump_trace(skip[,count])
5736 Actually collect the traceback information available via C<caller()>. It does
5737 some filtering and cleanup of the data, but mostly it just collects it to
5738 make C<print_trace()>'s job easier.
5740 C<skip> defines the number of stack frames to be skipped, working backwards
5741 from the most current. C<count> determines the total number of frames to
5742 be returned; all of them (well, the first 10^9) are returned if C<count>
5745 This routine returns a list of hashes, from most-recent to least-recent
5746 stack frame. Each has the following keys and values:
5750 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
5752 =item * C<sub> - subroutine name, or C<eval> information
5754 =item * C<args> - undef, or a reference to an array of arguments
5756 =item * C<file> - the file in which this item was defined (if any)
5758 =item * C<line> - the line on which it was defined
5766 # How many levels to skip.
5769 # How many levels to show. (1e9 is a cheap way of saying "all of them";
5770 # it's unlikely that we'll have more than a billion stack frames. If you
5771 # do, you've got an awfully big machine...)
5772 my $count = shift || 1e9;
5774 # We increment skip because caller(1) is the first level *back* from
5775 # the current one. Add $skip to the count of frames so we have a
5776 # simple stop criterion, counting from $skip to $count+$skip.
5780 # These variables are used to capture output from caller();
5781 my ( $p, $file, $line, $sub, $h, $context );
5783 my ( $e, $r, @a, @sub, $args );
5785 # XXX Okay... why'd we do that?
5786 my $nothard = not $frame & 8;
5789 # Do not want to trace this.
5790 my $otrace = $trace;
5793 # Start out at the skip count.
5794 # If we haven't reached the number of frames requested, and caller() is
5795 # still returning something, stay in the loop. (If we pass the requested
5796 # number of stack frames, or we run out - caller() returns nothing - we
5798 # Up the stack frame index to go back one more level each time.
5802 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
5807 # Go through the arguments and save them for later.
5811 if ( not defined $arg ) { # undefined parameter
5815 elsif ( $nothard and tied $arg ) { # tied parameter
5818 elsif ( $nothard and $type = ref $arg ) { # reference
5819 push @a, "ref($type)";
5821 else { # can be stringified
5823 "$arg"; # Safe to stringify now - should not call f().
5825 # Backslash any single-quotes or backslashes.
5828 # Single-quote it unless it's a number or a colon-separated
5831 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
5833 # Turn high-bit characters into meta-whatever.
5834 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
5836 # Turn control characters into ^-whatever.
5837 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
5840 } ## end else [ if (not defined $arg)
5841 } ## end for $arg (@args)
5843 # If context is true, this is array (@)context.
5844 # If context is false, this is scalar ($) context.
5845 # If neither, context isn't defined. (This is apparently a 'can't
5847 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
5849 # if the sub has args ($h true), make an anonymous array of the
5851 $args = $h ? [@a] : undef;
5853 # remove trailing newline-whitespace-semicolon-end of line sequence
5854 # from the eval text, if any.
5855 $e =~ s/\n\s*\;\s*\Z// if $e;
5857 # Escape backslashed single-quotes again if necessary.
5858 $e =~ s/([\\\'])/\\$1/g if $e;
5860 # if the require flag is true, the eval text is from a require.
5862 $sub = "require '$e'";
5865 # if it's false, the eval text is really from an eval.
5866 elsif ( defined $r ) {
5870 # If the sub is '(eval)', this is a block eval, meaning we don't
5871 # know what the eval'ed text actually was.
5872 elsif ( $sub eq '(eval)' ) {
5873 $sub = "eval {...}";
5876 # Stick the collected information into @sub as an anonymous hash.
5880 context => $context,
5888 # Stop processing frames if the user hit control-C.
5890 } ## end for ($i = $skip ; $i < ...
5892 # Restore the trace value again.
5895 } ## end sub dump_trace
5899 C<action()> takes input provided as the argument to an add-action command,
5900 either pre- or post-, and makes sure it's a complete command. It doesn't do
5901 any fancy parsing; it just keeps reading input until it gets a string
5902 without a trailing backslash.
5909 while ( $action =~ s/\\$// ) {
5911 # We have a backslash on the end. Read more.
5913 } ## end while ($action =~ s/\\$//)
5915 # Return the assembled action.
5921 This routine mostly just packages up a regular expression to be used
5922 to check that the thing it's being matched against has properly-matched
5925 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
5926 speeds things up by only creating the qr//'ed expression once; if it's
5927 already defined, we don't try to define it again. A speed hack.
5933 # I hate using globals!
5934 $balanced_brace_re ||= qr{
5937 (?> [^{}] + ) # Non-parens without backtracking
5939 (??{ $balanced_brace_re }) # Group with matching parens
5943 return $_[0] !~ m/$balanced_brace_re/;
5944 } ## end sub unbalanced
5948 C<gets()> is a primitive (very primitive) routine to read continuations.
5949 It was devised for reading continuations for actions.
5950 it just reads more input with C<readline()> and returns it.
5955 &readline("cont: ");
5958 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger
5960 The C<system()> function assumes that it can just go ahead and use STDIN and
5961 STDOUT, but under the debugger, we want it to use the debugger's input and
5964 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes
5965 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
5966 and then puts everything back again.
5972 # We save, change, then restore STDIN and STDOUT to avoid fork() since
5973 # some non-Unix systems can do system() but have problems with fork().
5974 open( SAVEIN, "<&STDIN" ) || &warn("Can't save STDIN");
5975 open( SAVEOUT, ">&STDOUT" ) || &warn("Can't save STDOUT");
5976 open( STDIN, "<&IN" ) || &warn("Can't redirect STDIN");
5977 open( STDOUT, ">&OUT" ) || &warn("Can't redirect STDOUT");
5979 # XXX: using csh or tcsh destroys sigint retvals!
5981 open( STDIN, "<&SAVEIN" ) || &warn("Can't restore STDIN");
5982 open( STDOUT, ">&SAVEOUT" ) || &warn("Can't restore STDOUT");
5986 # most of the $? crud was coping with broken cshisms
5988 &warn( "(Command exited ", ( $? >> 8 ), ")\n" );
5992 "(Command died of SIG#",
5994 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6003 =head1 TTY MANAGEMENT
6005 The subs here do some of the terminal management for multiple debuggers.
6009 Top-level function called when we want to set up a new terminal for use
6012 If the C<noTTY> debugger option was set, we'll either use the terminal
6013 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6014 to find one. If we're a forked debugger, we call C<resetterm> to try to
6015 get a whole new terminal if we can.
6017 In either case, we set up the terminal next. If the C<ReadLine> option was
6018 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6019 the appropriate attributes. We then
6025 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6028 eval { require Term::ReadLine } or die $@;
6030 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6033 my ( $i, $o ) = split $tty, /,/;
6034 $o = $i unless defined $o;
6035 open( IN, "<$i" ) or die "Cannot open TTY `$i' for read: $!";
6036 open( OUT, ">$o" ) or die "Cannot open TTY `$o' for write: $!";
6039 my $sel = select($OUT);
6044 # We don't have a TTY - try to find one via Term::Rendezvous.
6046 eval "require Term::Rendezvous;" or die;
6048 # See if we have anything to pass to Term::Rendezvous.
6049 # Use $HOME/.perldbtty$$ if not.
6050 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6052 # Rendezvous and get the filehandles.
6053 my $term_rv = new Term::Rendezvous $rv;
6055 $OUT = $term_rv->OUT;
6056 } ## end else [ if ($tty)
6057 } ## end if ($notty)
6059 # We're a daughter debugger. Try to fork off another TTY.
6060 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6064 # If we shouldn't use Term::ReadLine, don't.
6066 $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT;
6069 # We're using Term::ReadLine. Get all the attributes for this terminal.
6071 $term = new Term::ReadLine 'perldb', $IN, $OUT;
6073 $rl_attribs = $term->Attribs;
6074 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6075 if defined $rl_attribs->{basic_word_break_characters}
6076 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6077 $rl_attribs->{special_prefixes} = '$@&%';
6078 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6079 $rl_attribs->{completion_function} = \&db_complete;
6080 } ## end else [ if (!$rl)
6082 # Set up the LINEINFO filehandle.
6083 $LINEINFO = $OUT unless defined $LINEINFO;
6084 $lineinfo = $console unless defined $lineinfo;
6090 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6091 $term->SetHistory(@hist);
6094 # XXX Ornaments are turned on unconditionally, which is not
6095 # always a good thing.
6096 ornaments($ornaments) if defined $ornaments;
6098 } ## end sub setterm
6101 $histfile //= option_val("HistFile", undef);
6102 return unless defined $histfile;
6103 open my $fh, "<", $histfile or return;
6114 return unless defined $histfile;
6115 eval { require File::Path } or return;
6116 eval { require File::Basename } or return;
6117 File::Path::mkpath(File::Basename::dirname($histfile));
6118 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6119 $histsize //= option_val("HistSize",100);
6120 my @copy = grep { $_ ne '?' } @hist;
6121 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6122 for ($start .. $#copy) {
6123 print $fh "$copy[$_]\n";
6125 close $fh or die "Could not write '$histfile': $!";
6128 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6130 When the process being debugged forks, or the process invokes a command
6131 via C<system()> which starts a new debugger, we need to be able to get a new
6132 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6133 fight over the terminal, and you can never quite be sure who's going to get the
6134 input you're typing.
6136 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6137 is tasked with doing all the necessary operating system mojo to get a new
6138 TTY (and probably another window) and to direct the new debugger to read and
6141 The debugger provides C<get_fork_TTY> functions which work for X Windows,
6142 OS/2, and Mac OS X. Other systems are not supported. You are encouraged
6143 to write C<get_fork_TTY> functions which work for I<your> platform
6144 and contribute them.
6146 =head3 C<xterm_get_fork_TTY>
6148 This function provides the C<get_fork_TTY> function for X windows. If a
6149 program running under the debugger forks, a new <xterm> window is opened and
6150 the subsidiary debugger is directed there.
6152 The C<open()> call is of particular note here. We have the new C<xterm>
6153 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6154 command (which prints the device name of the TTY we'll want to use for input
6155 and output to STDOUT, then C<sleep> for a very long time, routing this output
6156 to file number 3. This way we can simply read from the <XT> filehandle (which
6157 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6159 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6164 sub xterm_get_fork_TTY {
6165 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6167 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6170 # Get the output from 'tty' and clean it up a little.
6174 $pidprompt = ''; # Shown anyway in titlebar
6176 # We need $term defined or we can not switch to the newly created xterm
6177 if ($tty ne '' && !defined $term) {
6178 eval { require Term::ReadLine } or die $@;
6180 $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT;
6183 $term = new Term::ReadLine 'perldb', $IN, $OUT;
6186 # There's our new TTY.
6188 } ## end sub xterm_get_fork_TTY
6190 =head3 C<os2_get_fork_TTY>
6192 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6196 # This example function resets $IN, $OUT itself
6198 sub os2_get_fork_TTY { # A simplification of the following (and works without):
6200 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6201 my %opt = ( title => "Daughter Perl debugger $pids $name",
6202 ($rl ? (read_by_key => 1) : ()) );
6203 require OS2::Process;
6204 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
6206 $pidprompt = ''; # Shown anyway in titlebar
6207 reset_IN_OUT($in, $out);
6209 return ''; # Indicate that reset_IN_OUT is called
6210 } ## end sub os2_get_fork_TTY
6212 =head3 C<macosx_get_fork_TTY>
6214 The Mac OS X version uses AppleScript to tell Terminal.app to create
6219 # Notes about Terminal.app's AppleScript support,
6220 # (aka things that might break in future OS versions).
6222 # The "do script" command doesn't return a reference to the new window
6223 # it creates, but since it appears frontmost and windows are enumerated
6224 # front to back, we can use "first window" === "window 1".
6226 # Since "do script" is implemented by supplying the argument (plus a
6227 # return character) as terminal input, there's a potential race condition
6228 # where the debugger could beat the shell to reading the command.
6229 # To prevent this, we wait for the screen to clear before proceeding.
6232 # There's no direct accessor for the tty device name, so we fiddle
6233 # with the window title options until it says what we want.
6236 # There _is_ a direct accessor for the tty device name, _and_ there's
6237 # a new possible component of the window title (the name of the settings
6238 # set). A separate version is needed.
6240 my @script_versions=
6242 ([237, <<'__LEOPARD__'],
6243 tell application "Terminal"
6244 do script "clear;exec sleep 100000"
6245 tell first tab of first window
6247 set custom title to "forked perl debugger"
6248 set title displays custom title to true
6249 repeat while (length of first paragraph of (get contents)) > 0
6257 [100, <<'__JAGUAR_TIGER__'],
6258 tell application "Terminal"
6259 do script "clear;exec sleep 100000"
6261 set title displays shell path to false
6262 set title displays window size to false
6263 set title displays file name to false
6264 set title displays device name to true
6265 set title displays custom title to true
6266 set custom title to ""
6267 copy "/dev/" & name to thetty
6268 set custom title to "forked perl debugger"
6269 repeat while (length of first paragraph of (get contents)) > 0
6279 sub macosx_get_fork_TTY
6281 my($version,$script,$pipe,$tty);
6283 return unless $version=$ENV{TERM_PROGRAM_VERSION};
6284 foreach my $entry (@script_versions) {
6285 if ($version>=$entry->[0]) {
6286 $script=$entry->[1];
6290 return unless defined($script);
6291 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
6292 $tty=readline($pipe);
6294 return unless defined($tty) && $tty =~ m(^/dev/);
6299 =head2 C<create_IN_OUT($flags)>
6301 Create a new pair of filehandles, pointing to a new TTY. If impossible,
6302 try to diagnose why.
6308 =item * 1 - Don't know how to create a new TTY.
6310 =item * 2 - Debugger has forked, but we can't get a new TTY.
6312 =item * 4 - standard debugger startup is happening.
6318 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
6320 # If we know how to get a new TTY, do it! $in will have
6321 # the TTY name if get_fork_TTY works.
6322 my $in = &get_fork_TTY if defined &get_fork_TTY;
6324 # It used to be that
6325 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
6327 if ( not defined $in ) {
6330 # We don't know how.
6331 print_help(<<EOP) if $why == 1;
6332 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6336 print_help(<<EOP) if $why == 2;
6337 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6338 This may be an asynchronous session, so the parent debugger may be active.
6341 # Note that both debuggers are fighting over the same input.
6342 print_help(<<EOP) if $why != 4;
6343 Since two debuggers fight for the same TTY, input is severely entangled.
6347 I know how to switch the output to a different window in xterms, OS/2
6348 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
6349 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
6350 B<DB::get_fork_TTY()> returning this.
6352 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6353 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6356 } ## end if (not defined $in)
6357 elsif ( $in ne '' ) {
6361 $console = ''; # Indicate no need to open-from-the-console
6364 } ## end sub create_IN_OUT
6368 Handles rejiggering the prompt when we've forked off a new debugger.
6370 If the new debugger happened because of a C<system()> that invoked a
6371 program under the debugger, the arrow between the old pid and the new
6372 in the prompt has I<two> dashes instead of one.
6374 We take the current list of pids and add this one to the end. If there
6375 isn't any list yet, we make one up out of the initial pid associated with
6376 the terminal and our new pid, sticking an arrow (either one-dashed or
6377 two dashed) in between them.
6379 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6380 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6385 sub resetterm { # We forked, so we need a different TTY
6387 # Needs to be passed to create_IN_OUT() as well.
6390 # resetterm(2): got in here because of a system() starting a debugger.
6391 # resetterm(1): just forked.
6392 my $systemed = $in > 1 ? '-' : '';
6394 # If there's already a list of pids, add this to the end.
6396 $pids =~ s/\]/$systemed->$$]/;
6399 # No pid list. Time to make one.
6401 $pids = "[$term_pid->$$]";
6404 # The prompt we're going to be using for this debugger.
6407 # We now 0wnz this terminal.
6410 # Just return if we're not supposed to try to create a new TTY.
6411 return unless $CreateTTY & $in;
6413 # Try to create a new IN/OUT pair.
6415 } ## end sub resetterm
6419 First, we handle stuff in the typeahead buffer. If there is any, we shift off
6420 the next line, print a message saying we got it, add it to the terminal
6421 history (if possible), and return it.
6423 If there's nothing in the typeahead buffer, check the command filehandle stack.
6424 If there are any filehandles there, read from the last one, and return the line
6425 if we got one. If not, we pop the filehandle off and close it, and try the
6426 next one up the stack.
6428 If we've emptied the filehandle stack, we check to see if we've got a socket
6429 open, and we read that and return it if we do. If we don't, we just call the
6430 core C<readline()> and return its value.
6436 # Localize to prevent it from being smashed in the program being debugged.
6439 # Pull a line out of the typeahead if there's stuff there.
6442 # How many lines left.
6443 my $left = @typeahead;
6445 # Get the next line.
6446 my $got = shift @typeahead;
6448 # Print a message saying we got input from the typeahead.
6450 print $OUT "auto(-$left)", shift, $got, "\n";
6452 # Add it to the terminal history (if possible).
6453 $term->AddHistory($got)
6455 and defined $term->Features->{addHistory};
6457 } ## end if (@typeahead)
6459 # We really need to read some input. Turn off entry/exit trace and
6460 # return value printing.
6464 # If there are stacked filehandles to read from ...
6467 # Read from the last one in the stack.
6468 my $line = CORE::readline( $cmdfhs[-1] );
6470 # If we got a line ...
6472 ? ( print $OUT ">> $line" and return $line ) # Echo and return
6473 : close pop @cmdfhs; # Pop and close
6474 } ## end while (@cmdfhs)
6476 # Nothing on the filehandle stack. Socket?
6477 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
6479 # Send anyting we have to send.
6480 $OUT->write( join( '', @_ ) );
6482 # Receive anything there is to receive.
6487 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
6488 # XXX Don't know. You tell me.
6489 } while length $buf and ($stuff .= $buf) !~ /\n/;
6493 } ## end if (ref $OUT and UNIVERSAL::isa...
6495 # No socket. Just read from the terminal.
6497 $term->readline(@_);
6499 } ## end sub readline
6501 =head1 OPTIONS SUPPORT ROUTINES
6503 These routines handle listing and setting option values.
6505 =head2 C<dump_option> - list the current value of an option setting
6507 This routine uses C<option_val> to look up the value for an option.
6508 It cleans up escaped single-quotes and then displays the option and
6514 my ( $opt, $val ) = @_;
6515 $val = option_val( $opt, 'N/A' );
6516 $val =~ s/([\\\'])/\\$1/g;
6517 printf $OUT "%20s = '%s'\n", $opt, $val;
6518 } ## end sub dump_option
6520 sub options2remember {
6521 foreach my $k (@RememberOnROptions) {
6522 $option{$k} = option_val( $k, 'N/A' );
6527 =head2 C<option_val> - find the current value of an option
6529 This can't just be a simple hash lookup because of the indirect way that
6530 the option values are stored. Some are retrieved by calling a subroutine,
6531 some are just variables.
6533 You must supply a default value to be used in case the option isn't set.
6538 my ( $opt, $default ) = @_;
6541 # Does this option exist, and is it a variable?
6542 # If so, retrieve the value via the value in %optionVars.
6543 if ( defined $optionVars{$opt}
6544 and defined ${ $optionVars{$opt} } )
6546 $val = ${ $optionVars{$opt} };
6549 # Does this option exist, and it's a subroutine?
6550 # If so, call the subroutine via the ref in %optionAction
6551 # and capture the value.
6552 elsif ( defined $optionAction{$opt}
6553 and defined &{ $optionAction{$opt} } )
6555 $val = &{ $optionAction{$opt} }();
6558 # If there's an action or variable for the supplied option,
6559 # but no value was set, use the default.
6560 elsif (defined $optionAction{$opt} and not defined $option{$opt}
6561 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
6566 # Otherwise, do the simple hash lookup.
6568 $val = $option{$opt};
6571 # If the value isn't defined, use the default.
6572 # Then return whatever the value is.
6573 $val = $default unless defined $val;
6575 } ## end sub option_val
6577 =head2 C<parse_options>
6579 Handles the parsing and execution of option setting/displaying commands.
6581 An option entered by itself is assumed to be I<set me to 1> (the default value)
6582 if the option is a boolean one. If not, the user is prompted to enter a valid
6583 value or to query the current value (via C<option? >).
6585 If C<option=value> is entered, we try to extract a quoted string from the
6586 value (if it is quoted). If it's not, we just use the whole value as-is.
6588 We load any modules required to service this option, and then we set it: if
6589 it just gets stuck in a variable, we do that; if there's a subroutine to
6590 handle setting the option, we call that.
6592 Finally, if we're running in interactive mode, we display the effect of the
6593 user's command back to the terminal, skipping this if we're setting things
6594 during initialization.
6602 # These options need a value. Don't allow them to be clobbered by accident.
6603 my %opt_needs_val = map { ( $_ => 1 ) } qw{
6604 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
6605 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
6611 # Clean off excess leading whitespace.
6614 # Options are always all word characters, followed by a non-word
6616 s/^(\w+)(\W?)// or print( $OUT "Invalid option `$_'\n" ), last;
6617 my ( $opt, $sep ) = ( $1, $2 );
6619 # Make sure that such an option exists.
6620 my $matches = grep( /^\Q$opt/ && ( $option = $_ ), @options )
6621 || grep( /^\Q$opt/i && ( $option = $_ ), @options );
6623 print( $OUT "Unknown option `$opt'\n" ), next unless $matches;
6624 print( $OUT "Ambiguous option `$opt'\n" ), next if $matches > 1;
6627 # '?' as separator means query, but must have whitespace after it.
6628 if ( "?" eq $sep ) {
6629 print( $OUT "Option query `$opt?' followed by non-space `$_'\n" ),
6633 #&dump_option($opt);
6634 } ## end if ("?" eq $sep)
6636 # Separator is whitespace (or just a carriage return).
6637 # They're going for a default, which we assume is 1.
6638 elsif ( $sep !~ /\S/ ) {
6640 $val = "1"; # this is an evil default; make 'em set it!
6643 # Separator is =. Trying to set a value.
6644 elsif ( $sep eq "=" ) {
6646 # If quoted, extract a quoted string.
6647 if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
6649 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
6652 # Not quoted. Use the whole thing. Warn about 'option='.
6656 print OUT qq(Option better cleared using $opt=""\n)
6658 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
6660 } ## end elsif ($sep eq "=")
6662 # "Quoted" with [], <>, or {}.
6663 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
6665 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
6666 s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
6667 or print( $OUT "Unclosed option value `$opt$sep$_'\n" ), last;
6668 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
6669 } ## end else [ if ("?" eq $sep)
6671 # Exclude non-booleans from getting set to 1 by default.
6672 if ( $opt_needs_val{$option} && $val_defaulted ) {
6673 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
6675 "Option `$opt' is non-boolean. Use `$cmd $option=VAL' to set, `$cmd $option?' to query\n";
6677 } ## end if ($opt_needs_val{$option...
6679 # Save the option value.
6680 $option{$option} = $val if defined $val;
6682 # Load any module that this option requires.
6686 require '$optionRequire{$option}';
6688 } || die # XXX: shouldn't happen
6689 if defined $optionRequire{$option}
6693 # Stick it in the proper variable if it goes in a variable.
6694 ${ $optionVars{$option} } = $val
6695 if defined $optionVars{$option}
6698 # Call the appropriate sub if it gets set via sub.
6699 &{ $optionAction{$option} }($val)
6700 if defined $optionAction{$option}
6701 && defined &{ $optionAction{$option} }
6704 # Not initialization - echo the value we set it to.
6705 dump_option($option) unless $OUT eq \*STDERR;
6706 } ## end while (length)
6707 } ## end sub parse_options
6709 =head1 RESTART SUPPORT
6711 These routines are used to store (and restore) lists of items in environment
6712 variables during a restart.
6716 Set_list packages up items to be stored in a set of environment variables
6717 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
6718 the values). Values outside the standard ASCII charset are stored by encoding
6719 then as hexadecimal values.
6724 my ( $stem, @list ) = @_;
6727 # VAR_n: how many we have. Scalar assignment gets the number of items.
6728 $ENV{"${stem}_n"} = @list;
6730 # Grab each item in the list, escape the backslashes, encode the non-ASCII
6731 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
6732 for $i ( 0 .. $#list ) {
6734 $val =~ s/\\/\\\\/g;
6735 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
6736 $ENV{"${stem}_$i"} = $val;
6737 } ## end for $i (0 .. $#list)
6738 } ## end sub set_list
6742 Reverse the set_list operation: grab VAR_n to see how many we should be getting
6743 back, and then pull VAR_0, VAR_1. etc. back out.
6750 my $n = delete $ENV{"${stem}_n"};
6752 for $i ( 0 .. $n - 1 ) {
6753 $val = delete $ENV{"${stem}_$i"};
6754 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
6758 } ## end sub get_list
6760 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
6764 The C<catch()> subroutine is the essence of fast and low-impact. We simply
6765 set an already-existing global scalar variable to a constant value. This
6766 avoids allocating any memory possibly in the middle of something that will
6767 get all confused if we do, particularly under I<unsafe signals>.
6773 return; # Put nothing on the stack - malloc/free land!
6778 C<warn> emits a warning, by joining together its arguments and printing
6779 them, with couple of fillips.
6781 If the composited message I<doesn't> end with a newline, we automatically
6782 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
6783 to be set to the filehandle to be used to output warnings; it makes no
6784 assumptions about what filehandles are available.
6789 my ($msg) = join( "", @_ );
6790 $msg .= ": $!\n" unless $msg =~ /\n$/;
6795 =head1 INITIALIZATION TTY SUPPORT
6797 =head2 C<reset_IN_OUT>
6799 This routine handles restoring the debugger's input and output filehandles
6800 after we've tried and failed to move them elsewhere. In addition, it assigns
6801 the debugger's output filehandle to $LINEINFO if it was already open there.
6806 my $switch_li = $LINEINFO eq $OUT;
6808 # If there's a term and it's able to get a new tty, try to get one.
6809 if ( $term and $term->Features->{newTTY} ) {
6810 ( $IN, $OUT ) = ( shift, shift );
6811 $term->newTTY( $IN, $OUT );
6814 # This term can't get a new tty now. Better luck later.
6816 &warn("Too late to set IN/OUT filehandles, enabled on next `R'!\n");
6819 # Set the filehndles up as they were.
6821 ( $IN, $OUT ) = ( shift, shift );
6824 # Unbuffer the output filehandle.
6825 my $o = select $OUT;
6829 # Point LINEINFO to the same output filehandle if it was there before.
6830 $LINEINFO = $OUT if $switch_li;
6831 } ## end sub reset_IN_OUT
6833 =head1 OPTION SUPPORT ROUTINES
6835 The following routines are used to process some of the more complicated
6840 Sets the input and output filehandles to the specified files or pipes.
6841 If the terminal supports switching, we go ahead and do it. If not, and
6842 there's already a terminal in place, we save the information to take effect
6845 If there's no terminal yet (for instance, during debugger initialization),
6846 we go ahead and set C<$console> and C<$tty> to the file indicated.
6852 if ( @_ and $term and $term->Features->{newTTY} ) {
6854 # This terminal supports switching to a new TTY.
6855 # Can be a list of two files, or on string containing both names,
6857 # XXX Should this perhaps be an assignment from @_?
6858 my ( $in, $out ) = shift;
6861 # Split list apart if supplied.
6862 ( $in, $out ) = split /,/, $in, 2;
6866 # Use the same file for both input and output.
6870 # Open file onto the debugger's filehandles, if you can.
6871 open IN, $in or die "cannot open `$in' for read: $!";
6872 open OUT, ">$out" or die "cannot open `$out' for write: $!";
6874 # Swap to the new filehandles.
6875 reset_IN_OUT( \*IN, \*OUT );
6877 # Save the setting for later.
6879 } ## end if (@_ and $term and $term...
6881 # Terminal doesn't support new TTY, or doesn't support readline.
6882 # Can't do it now, try restarting.
6883 &warn("Too late to set TTY, enabled on next `R'!\n") if $term and @_;
6885 # Useful if done through PERLDB_OPTS:
6886 $console = $tty = shift if @_;
6888 # Return whatever the TTY is.
6894 Sets the C<$notty> global, controlling whether or not the debugger tries to
6895 get a terminal to read from. If called after a terminal is already in place,
6896 we save the value to use it if we're restarted.
6902 &warn("Too late to set noTTY, enabled on next `R'!\n") if @_;
6904 $notty = shift if @_;
6910 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
6911 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
6912 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
6913 the value in case a restart is done so we can change it then.
6919 &warn("Too late to set ReadLine, enabled on next `R'!\n") if @_;
6923 } ## end sub ReadLine
6925 =head2 C<RemotePort>
6927 Sets the port that the debugger will try to connect to when starting up.
6928 If the terminal's already been set up, we can't do it, but we remember the
6929 setting in case the user does a restart.
6935 &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
6937 $remoteport = shift if @_;
6939 } ## end sub RemotePort
6943 Checks with the terminal to see if C<Tk> is running, and returns true or
6944 false. Returns false if the current terminal doesn't support C<readline>.
6949 if ( ${ $term->Features }{tkRunning} ) {
6950 return $term->tkRunning(@_);
6954 print $OUT "tkRunning not supported by current ReadLine package.\n";
6957 } ## end sub tkRunning
6961 Sets nonstop mode. If a terminal's already been set up, it's too late; the
6962 debugger remembers the setting in case you restart, though.
6968 &warn("Too late to set up NonStop mode, enabled on next `R'!\n")
6971 $runnonstop = shift if @_;
6973 } ## end sub NonStop
6977 &warn("Some flag changes could not take effect until next 'R'!\n")
6980 $^P = parse_DollarCaretP_flags(shift) if @_;
6981 expand_DollarCaretP_flags($^P);
6986 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
6994 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7001 Sets the shell escape command, and generates a printable copy to be used
7008 # If we got an argument, meta-quote it, and add '\b' if it
7009 # ends in a word character.
7011 $sh = quotemeta shift;
7012 $sh .= "\\b" if $sh =~ /\w$/;
7015 # Generate the printable version for the help:
7016 $psh = $sh; # copy it
7017 $psh =~ s/\\b$//; # Take off trailing \b if any
7018 $psh =~ s/\\(.)/$1/g; # De-escape
7019 $psh; # return the printable version
7020 } ## end sub shellBang
7024 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7025 was passed as the argument. (This means you can't override the terminal's
7031 if ( defined $term ) {
7033 # We don't want to show warning backtraces, but we do want die() ones.
7034 local ( $warnLevel, $dieLevel ) = ( 0, 1 );
7036 # No ornaments if the terminal doesn't support them.
7037 return '' unless $term->Features->{ornaments};
7038 eval { $term->ornaments(@_) } || '';
7041 # Use what was passed in if we can't determine it ourselves.
7045 } ## end sub ornaments
7047 =head2 C<recallCommand>
7049 Sets the recall command, and builds a printable version which will appear in
7056 # If there is input, metaquote it. Add '\b' if it ends with a word
7059 $rc = quotemeta shift;
7060 $rc .= "\\b" if $rc =~ /\w$/;
7063 # Build it into a printable version.
7064 $prc = $rc; # Copy it
7065 $prc =~ s/\\b$//; # Remove trailing \b
7066 $prc =~ s/\\(.)/$1/g; # Remove escapes
7067 $prc; # Return the printable version
7068 } ## end sub recallCommand
7070 =head2 C<LineInfo> - where the line number information goes
7072 Called with no arguments, returns the file or pipe that line info should go to.
7074 Called with an argument (a file or a pipe), it opens that onto the
7075 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7076 file or pipe again to the caller.
7081 return $lineinfo unless @_;
7084 # If this is a valid "thing to be opened for output", tack a
7085 # '>' onto the front.
7086 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7088 # If this is a pipe, the stream points to a slave editor.
7089 $slave_editor = ( $stream =~ /^\|/ );
7091 # Open it up and unbuffer it.
7092 open( LINEINFO, "$stream" ) || &warn("Cannot open `$stream' for write");
7093 $LINEINFO = \*LINEINFO;
7094 my $save = select($LINEINFO);
7098 # Hand the file or pipe back again.
7100 } ## end sub LineInfo
7102 =head1 COMMAND SUPPORT ROUTINES
7104 These subroutines provide functionality for various commands.
7106 =head2 C<list_modules>
7108 For the C<M> command: list modules loaded and their versions.
7109 Essentially just runs through the keys in %INC, picks each package's
7110 C<$VERSION> variable, gets the file name, and formats the information
7115 sub list_modules { # versions
7119 # keys are the "as-loaded" name, values are the fully-qualified path
7120 # to the file itself.
7122 $file = $_; # get the module name
7123 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7124 s,/,::,g; # change '/' to '::'
7125 s/^perl5db$/DB/; # Special case: debugger
7126 # moves to package DB
7127 s/^Term::ReadLine::readline$/readline/; # simplify readline
7129 # If the package has a $VERSION package global (as all good packages
7130 # should!) decode it and save as partial message.
7131 if ( defined ${ $_ . '::VERSION' } ) {
7132 $version{$file} = "${ $_ . '::VERSION' } from ";
7135 # Finish up the message with the file the package came from.
7136 $version{$file} .= $INC{$file};
7137 } ## end for (keys %INC)
7139 # Hey, dumpit() formats a hash nicely, so why not use it?
7140 dumpit( $OUT, \%version );
7141 } ## end sub list_modules
7145 Sets up the monster string used to format and print the help.
7147 =head3 HELP MESSAGE FORMAT
7149 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
7150 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
7151 easy to parse and portable, but which still allows the help to be a little
7152 nicer than just plain text.
7154 Essentially, you define the command name (usually marked up with C<< B<> >>
7155 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
7156 newline. The descriptive text can also be marked up in the same way. If you
7157 need to continue the descriptive text to another line, start that line with
7158 just tabs and then enter the marked-up text.
7160 If you are modifying the help text, I<be careful>. The help-string parser is
7161 not very sophisticated, and if you don't follow these rules it will mangle the
7162 help beyond hope until you fix the string.
7168 # XXX: make sure there are tabs between the command and explanation,
7169 # or print_help will screw up your formatting if you have
7170 # eeevil ornaments enabled. This is an insane mess.
7173 Help is currently only available for the new 5.8 command set.
7174 No help is available for the old command set.
7175 We assume you know what you're doing if you switch to it.
7178 B<s> [I<expr>] Single step [in I<expr>].
7179 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7180 <B<CR>> Repeat last B<n> or B<s> command.
7181 B<r> Return from current subroutine.
7182 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7183 at the specified position.
7184 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7185 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7186 B<l> I<line> List single I<line>.
7187 B<l> I<subname> List first window of lines from subroutine.
7188 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7189 B<l> List next window of lines.
7190 B<-> List previous window of lines.
7191 B<v> [I<line>] View window around I<line>.
7192 B<.> Return to the executed line.
7193 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7194 I<filename> may be either the full name of the file, or a regular
7195 expression matching the full file name:
7196 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7197 Evals (with saved bodies) are considered to be filenames:
7198 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7199 (in the order of execution).
7200 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7201 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7202 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
7203 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7204 B<t> Toggle trace mode.
7205 B<t> I<expr> Trace through execution of I<expr>.
7206 B<b> Sets breakpoint on current line)
7207 B<b> [I<line>] [I<condition>]
7208 Set breakpoint; I<line> defaults to the current execution line;
7209 I<condition> breaks if it evaluates to true, defaults to '1'.
7210 B<b> I<subname> [I<condition>]
7211 Set breakpoint at first line of subroutine.
7212 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7213 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7214 B<b> B<postpone> I<subname> [I<condition>]
7215 Set breakpoint at first line of subroutine after
7217 B<b> B<compile> I<subname>
7218 Stop after the subroutine is compiled.
7219 B<B> [I<line>] Delete the breakpoint for I<line>.
7220 B<B> I<*> Delete all breakpoints.
7221 B<a> [I<line>] I<command>
7222 Set an action to be done before the I<line> is executed;
7223 I<line> defaults to the current execution line.
7224 Sequence is: check for breakpoint/watchpoint, print line
7225 if necessary, do action, prompt user if necessary,
7228 B<A> [I<line>] Delete the action for I<line>.
7229 B<A> I<*> Delete all actions.
7230 B<w> I<expr> Add a global watch-expression.
7232 B<W> I<expr> Delete a global watch-expression.
7233 B<W> I<*> Delete all watch-expressions.
7234 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7235 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7236 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7237 B<x> I<expr> Evals expression in list context, dumps the result.
7238 B<m> I<expr> Evals expression in list context, prints methods callable
7239 on the first element of the result.
7240 B<m> I<class> Prints methods callable via the given class.
7241 B<M> Show versions of loaded modules.
7242 B<i> I<class> Prints nested parents of given class.
7243 B<e> Display current thread id.
7244 B<E> Display all thread ids the current one will be identified: <n>.
7245 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7247 B<<> ? List Perl commands to run before each prompt.
7248 B<<> I<expr> Define Perl command to run before each prompt.
7249 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7250 B<< *> Delete the list of perl commands to run before each prompt.
7251 B<>> ? List Perl commands to run after each prompt.
7252 B<>> I<expr> Define Perl command to run after each prompt.
7253 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7254 B<>>B< *> Delete the list of Perl commands to run after each prompt.
7255 B<{> I<db_command> Define debugger command to run before each prompt.
7256 B<{> ? List debugger commands to run before each prompt.
7257 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7258 B<{ *> Delete the list of debugger commands to run before each prompt.
7259 B<$prc> I<number> Redo a previous command (default previous command).
7260 B<$prc> I<-number> Redo number'th-to-last command.
7261 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7262 See 'B<O> I<recallCommand>' too.
7263 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7268 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7270 See 'B<O> I<shellBang>' too.
7271 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7272 B<save> I<file> Save current debugger session (actual history) to I<file>.
7273 B<rerun> Rerun session to current position.
7274 B<rerun> I<n> Rerun session to numbered command.
7275 B<rerun> I<-n> Rerun session to number'th-to-last command.
7276 B<H> I<-number> Display last number commands (default all).
7277 B<H> I<*> Delete complete history.
7278 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7279 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7280 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7281 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7282 I<command> Execute as a perl statement in current package.
7283 B<R> Pure-man-restart of debugger, some of debugger state
7284 and command-line options may be lost.
7285 Currently the following settings are preserved:
7286 history, breakpoints and actions, debugger B<O>ptions
7287 and the following command-line options: I<-w>, I<-I>, I<-e>.
7289 B<o> [I<opt>] ... Set boolean option to true
7290 B<o> [I<opt>B<?>] Query options
7291 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7292 Set options. Use quotes if spaces in value.
7293 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7294 I<pager> program for output of \"|cmd\";
7295 I<tkRunning> run Tk while prompting (with ReadLine);
7296 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7297 I<inhibit_exit> Allows stepping off the end of the script.
7298 I<ImmediateStop> Debugger should stop as early as possible.
7299 I<RemotePort> Remote hostname:port for remote debugging
7300 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7301 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7302 I<compactDump>, I<veryCompact> change style of array and hash dump;
7303 I<globPrint> whether to print contents of globs;
7304 I<DumpDBFiles> dump arrays holding debugged files;
7305 I<DumpPackages> dump symbol tables of packages;
7306 I<DumpReused> dump contents of \"reused\" addresses;
7307 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7308 I<bareStringify> Do not print the overload-stringified value;
7309 Other options include:
7310 I<PrintRet> affects printing of return value after B<r> command,
7311 I<frame> affects printing messages on subroutine entry/exit.
7312 I<AutoTrace> affects printing messages on possible breaking points.
7313 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7314 I<ornaments> affects screen appearance of the command line.
7315 I<CreateTTY> bits control attempts to create a new TTY on events:
7316 1: on fork() 2: debugger is started inside debugger
7318 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7319 You can put additional initialization options I<TTY>, I<noTTY>,
7320 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7321 `B<R>' after you set them).
7323 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7324 B<h> Summary of debugger commands.
7325 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7326 B<h h> Long help for debugger commands
7327 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7328 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7329 Set B<\$DB::doccmd> to change viewer.
7331 Type `|h h' for a paged display if this was too hard to read.
7333 "; # Fix balance of vi % matching: }}}}
7335 # note: tabs in the following section are not-so-helpful
7336 $summary = <<"END_SUM";
7337 I<List/search source lines:> I<Control script execution:>
7338 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7339 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7340 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7341 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7342 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7343 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7344 I<Debugger controls:> B<L> List break/watch/actions
7345 B<o> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7346 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7347 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7348 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7349 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7350 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7351 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7352 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7353 B<q> or B<^D> Quit B<R> Attempt a restart
7354 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7355 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7356 B<p> I<expr> Print expression (uses script's current package).
7357 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7358 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7359 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
7360 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7361 B<e> Display thread id B<E> Display all thread ids.
7362 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7365 # ')}}; # Fix balance of vi % matching
7367 # and this is really numb...
7370 B<s> [I<expr>] Single step [in I<expr>].
7371 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7372 B<CR>> Repeat last B<n> or B<s> command.
7373 B<r> Return from current subroutine.
7374 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7375 at the specified position.
7376 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7377 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7378 B<l> I<line> List single I<line>.
7379 B<l> I<subname> List first window of lines from subroutine.
7380 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7381 B<l> List next window of lines.
7382 B<-> List previous window of lines.
7383 B<w> [I<line>] List window around I<line>.
7384 B<.> Return to the executed line.
7385 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7386 I<filename> may be either the full name of the file, or a regular
7387 expression matching the full file name:
7388 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7389 Evals (with saved bodies) are considered to be filenames:
7390 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7391 (in the order of execution).
7392 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7393 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7394 B<L> List all breakpoints and actions.
7395 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7396 B<t> Toggle trace mode.
7397 B<t> I<expr> Trace through execution of I<expr>.
7398 B<b> [I<line>] [I<condition>]
7399 Set breakpoint; I<line> defaults to the current execution line;
7400 I<condition> breaks if it evaluates to true, defaults to '1'.
7401 B<b> I<subname> [I<condition>]
7402 Set breakpoint at first line of subroutine.
7403 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7404 B<b> B<load> I<filename> Set breakpoint on `require'ing the given file.
7405 B<b> B<postpone> I<subname> [I<condition>]
7406 Set breakpoint at first line of subroutine after
7408 B<b> B<compile> I<subname>
7409 Stop after the subroutine is compiled.
7410 B<d> [I<line>] Delete the breakpoint for I<line>.
7411 B<D> Delete all breakpoints.
7412 B<a> [I<line>] I<command>
7413 Set an action to be done before the I<line> is executed;
7414 I<line> defaults to the current execution line.
7415 Sequence is: check for breakpoint/watchpoint, print line
7416 if necessary, do action, prompt user if necessary,
7418 B<a> [I<line>] Delete the action for I<line>.
7419 B<A> Delete all actions.
7420 B<W> I<expr> Add a global watch-expression.
7421 B<W> Delete all watch-expressions.
7422 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7423 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7424 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7425 B<x> I<expr> Evals expression in list context, dumps the result.
7426 B<m> I<expr> Evals expression in list context, prints methods callable
7427 on the first element of the result.
7428 B<m> I<class> Prints methods callable via the given class.
7430 B<<> ? List Perl commands to run before each prompt.
7431 B<<> I<expr> Define Perl command to run before each prompt.
7432 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7433 B<>> ? List Perl commands to run after each prompt.
7434 B<>> I<expr> Define Perl command to run after each prompt.
7435 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7436 B<{> I<db_command> Define debugger command to run before each prompt.
7437 B<{> ? List debugger commands to run before each prompt.
7438 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7439 B<$prc> I<number> Redo a previous command (default previous command).
7440 B<$prc> I<-number> Redo number'th-to-last command.
7441 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7442 See 'B<O> I<recallCommand>' too.
7443 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7448 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7450 See 'B<O> I<shellBang>' too.
7451 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7452 B<H> I<-number> Display last number commands (default all).
7453 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7454 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7455 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7456 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7457 I<command> Execute as a perl statement in current package.
7458 B<v> Show versions of loaded modules.
7459 B<R> Pure-man-restart of debugger, some of debugger state
7460 and command-line options may be lost.
7461 Currently the following settings are preserved:
7462 history, breakpoints and actions, debugger B<O>ptions
7463 and the following command-line options: I<-w>, I<-I>, I<-e>.
7465 B<O> [I<opt>] ... Set boolean option to true
7466 B<O> [I<opt>B<?>] Query options
7467 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7468 Set options. Use quotes if spaces in value.
7469 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7470 I<pager> program for output of \"|cmd\";
7471 I<tkRunning> run Tk while prompting (with ReadLine);
7472 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7473 I<inhibit_exit> Allows stepping off the end of the script.
7474 I<ImmediateStop> Debugger should stop as early as possible.
7475 I<RemotePort> Remote hostname:port for remote debugging
7476 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7477 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7478 I<compactDump>, I<veryCompact> change style of array and hash dump;
7479 I<globPrint> whether to print contents of globs;
7480 I<DumpDBFiles> dump arrays holding debugged files;
7481 I<DumpPackages> dump symbol tables of packages;
7482 I<DumpReused> dump contents of \"reused\" addresses;
7483 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7484 I<bareStringify> Do not print the overload-stringified value;
7485 Other options include:
7486 I<PrintRet> affects printing of return value after B<r> command,
7487 I<frame> affects printing messages on subroutine entry/exit.
7488 I<AutoTrace> affects printing messages on possible breaking points.
7489 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7490 I<ornaments> affects screen appearance of the command line.
7491 I<CreateTTY> bits control attempts to create a new TTY on events:
7492 1: on fork() 2: debugger is started inside debugger
7494 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7495 You can put additional initialization options I<TTY>, I<noTTY>,
7496 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7497 `B<R>' after you set them).
7499 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7500 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7501 B<h h> Summary of debugger commands.
7502 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7503 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7504 Set B<\$DB::doccmd> to change viewer.
7506 Type `|h' for a paged display if this was too hard to read.
7508 "; # Fix balance of vi % matching: }}}}
7510 # note: tabs in the following section are not-so-helpful
7511 $pre580_summary = <<"END_SUM";
7512 I<List/search source lines:> I<Control script execution:>
7513 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7514 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7515 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
7516 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7517 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7518 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
7519 I<Debugger controls:> B<L> List break/watch/actions
7520 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7521 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7522 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
7523 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7524 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
7525 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
7526 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7527 B<q> or B<^D> Quit B<R> Attempt a restart
7528 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7529 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7530 B<p> I<expr> Print expression (uses script's current package).
7531 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7532 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7533 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
7534 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7535 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7538 # ')}}; # Fix balance of vi % matching
7540 } ## end sub sethelp
7542 =head2 C<print_help()>
7544 Most of what C<print_help> does is just text formatting. It finds the
7545 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
7546 terminal control characters to simulate them (courtesy of
7547 C<Term::ReadLine::TermCap>).
7554 # Restore proper alignment destroyed by eeevil I<> and B<>
7555 # ornaments: A pox on both their houses!
7557 # A help command will have everything up to and including
7558 # the first tab sequence padded into a field 16 (or if indented 20)
7559 # wide. If it's wider than that, an extra space will be added.
7561 ^ # only matters at start of line
7562 ( \040{4} | \t )* # some subcommands are indented
7563 ( < ? # so <CR> works
7564 [BI] < [^\t\n] + ) # find an eeevil ornament
7565 ( \t+ ) # original separation, discarded
7566 ( .* ) # this will now start (no earlier) than
7569 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
7570 my $clean = $command;
7571 $clean =~ s/[BI]<([^>]*)>/$1/g;
7573 # replace with this whole string:
7574 ($leadwhite ? " " x 4 : "")
7576 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
7581 s{ # handle bold ornaments
7582 B < ( [^>] + | > ) >
7584 $Term::ReadLine::TermCap::rl_term_set[2]
7586 . $Term::ReadLine::TermCap::rl_term_set[3]
7589 s{ # handle italic ornaments
7590 I < ( [^>] + | > ) >
7592 $Term::ReadLine::TermCap::rl_term_set[0]
7594 . $Term::ReadLine::TermCap::rl_term_set[1]
7599 } ## end sub print_help
7603 This routine does a lot of gyrations to be sure that the pager is C<less>.
7604 It checks for C<less> masquerading as C<more> and records the result in
7605 C<$ENV{LESS}> so we don't have to go through doing the stats again.
7611 # We already know if this is set.
7612 return if defined $ENV{LESS} && $ENV{LESS} =~ /r/;
7614 # Pager is less for sure.
7615 my $is_less = $pager =~ /\bless\b/;
7616 if ( $pager =~ /\bmore\b/ ) {
7618 # Nope, set to more. See what's out there.
7619 my @st_more = stat('/usr/bin/more');
7620 my @st_less = stat('/usr/bin/less');
7622 # is it really less, pretending to be more?
7625 && $st_more[0] == $st_less[0]
7626 && $st_more[1] == $st_less[1];
7627 } ## end if ($pager =~ /\bmore\b/)
7629 # changes environment!
7630 # 'r' added so we don't do (slow) stats again.
7631 $ENV{LESS} .= 'r' if $is_less;
7632 } ## end sub fix_less
7634 =head1 DIE AND WARN MANAGEMENT
7638 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
7639 to debug a debugger problem.
7641 It does its best to report the error that occurred, and then forces the
7642 program, debugger, and everything to die.
7648 # No entry/exit messages.
7651 # No return value prints.
7654 # set the abort signal handling to the default (just terminate).
7655 $SIG{'ABRT'} = 'DEFAULT';
7657 # If we enter the signal handler recursively, kill myself with an
7658 # abort signal (so we just terminate).
7659 kill 'ABRT', $$ if $panic++;
7661 # If we can show detailed info, do so.
7662 if ( defined &Carp::longmess ) {
7664 # Don't recursively enter the warn handler, since we're carping.
7665 local $SIG{__WARN__} = '';
7667 # Skip two levels before reporting traceback: we're skipping
7668 # mydie and confess.
7669 local $Carp::CarpLevel = 2; # mydie + confess
7671 # Tell us all about it.
7672 &warn( Carp::longmess("Signal @_") );
7675 # No Carp. Tell us about the signal as best we can.
7678 print $DB::OUT "Got signal @_\n";
7683 } ## end sub diesignal
7687 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
7688 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
7694 # No entry/exit trace.
7697 # No return value printing.
7700 # Turn off warn and die handling to prevent recursive entries to this
7702 local $SIG{__WARN__} = '';
7703 local $SIG{__DIE__} = '';
7705 # Load Carp if we can. If $^S is false (current thing being compiled isn't
7706 # done yet), we may not be able to do a require.
7707 eval { require Carp }
7708 if defined $^S; # If error/warning during compilation,
7709 # require may be broken.
7711 # Use the core warn() unless Carp loaded OK.
7713 "\nCannot print stack trace, load with -MCarp option to see stack" ),
7715 unless defined &Carp::longmess;
7717 # Save the current values of $single and $trace, and then turn them off.
7718 my ( $mysingle, $mytrace ) = ( $single, $trace );
7722 # We can call Carp::longmess without its being "debugged" (which we
7723 # don't want - we just want to use it!). Capture this for later.
7724 my $mess = Carp::longmess(@_);
7726 # Restore $single and $trace to their original values.
7727 ( $single, $trace ) = ( $mysingle, $mytrace );
7729 # Use the debugger's own special way of printing warnings to print
7730 # the stack trace message.
7736 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
7737 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
7738 single stepping and tracing during the call to C<Carp::longmess> to avoid
7739 debugging it - we just want to use it.
7741 If C<dieLevel> is zero, we let the program being debugged handle the
7742 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
7743 the debugger takes over all exception handling, printing a backtrace and
7744 displaying the exception via its C<dbwarn()> routine.
7751 local $SIG{__DIE__} = '';
7752 local $SIG{__WARN__} = '';
7756 if ( $dieLevel > 2 ) {
7757 local $SIG{__WARN__} = \&dbwarn;
7758 &warn(@_); # Yell no matter what
7761 if ( $dieLevel < 2 ) {
7762 die @_ if $^S; # in eval propagate
7765 # The code used to check $^S to see if compiliation of the current thing
7766 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
7767 eval { require Carp };
7770 "\nCannot print stack trace, load with -MCarp option to see stack" )
7771 unless defined &Carp::longmess;
7773 # We do not want to debug this chunk (automatic disabling works
7774 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
7775 # get the stack trace from Carp::longmess (if possible), restore $signal
7776 # and $trace, and then die with the stack trace.
7777 my ( $mysingle, $mytrace ) = ( $single, $trace );
7783 package Carp; # Do not include us in the list
7784 eval { $mess = Carp::longmess(@_); };
7786 ( $single, $trace ) = ( $mysingle, $mytrace );
7790 =head2 C<warnlevel()>
7792 Set the C<$DB::warnLevel> variable that stores the value of the
7793 C<warnLevel> option. Calling C<warnLevel()> with a positive value
7794 results in the debugger taking over all warning handlers. Setting
7795 C<warnLevel> to zero leaves any warning handlers set up by the program
7796 being debugged in place.
7802 $prevwarn = $SIG{__WARN__} unless $warnLevel;
7805 $SIG{__WARN__} = \&DB::dbwarn;
7808 $SIG{__WARN__} = $prevwarn;
7810 undef $SIG{__WARN__};
7814 } ## end sub warnLevel
7818 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
7819 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
7820 zero lets you use your own C<die()> handler.
7827 $prevdie = $SIG{__DIE__} unless $dieLevel;
7831 # Always set it to dbdie() for non-zero values.
7832 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
7834 # No longer exists, so don't try to use it.
7835 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
7837 # If we've finished initialization, mention that stack dumps
7838 # are enabled, If dieLevel is 1, we won't stack dump if we die
7840 print $OUT "Stack dump during die enabled",
7841 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
7844 # XXX This is probably obsolete, given that diehard() is gone.
7845 print $OUT "Dump printed too.\n" if $dieLevel > 2;
7846 } ## end if ($dieLevel)
7848 # Put the old one back if there was one.
7850 $SIG{__DIE__} = $prevdie;
7851 print $OUT "Default die handler restored.\n";
7853 undef $SIG{__DIE__};
7854 print $OUT "Die handler removed.\n";
7858 } ## end sub dieLevel
7860 =head2 C<signalLevel>
7862 Number three in a series: set C<signalLevel> to zero to keep your own
7863 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
7864 takes over and handles them with C<DB::diesignal()>.
7870 $prevsegv = $SIG{SEGV} unless $signalLevel;
7871 $prevbus = $SIG{BUS} unless $signalLevel;
7872 $signalLevel = shift;
7874 $SIG{SEGV} = \&DB::diesignal;
7875 $SIG{BUS} = \&DB::diesignal;
7878 $SIG{SEGV} = $prevsegv;
7879 $SIG{BUS} = $prevbus;
7883 } ## end sub signalLevel
7885 =head1 SUBROUTINE DECODING SUPPORT
7887 These subroutines are used during the C<x> and C<X> commands to try to
7888 produce as much information as possible about a code reference. They use
7889 L<Devel::Peek> to try to find the glob in which this code reference lives
7890 (if it does) - this allows us to actually code references which correspond
7891 to named subroutines (including those aliased via glob assignment).
7893 =head2 C<CvGV_name()>
7895 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
7896 via that routine. If this fails, return the reference again (when the
7897 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
7903 my $name = CvGV_name_or_bust($in);
7904 defined $name ? $name : $in;
7907 =head2 C<CvGV_name_or_bust> I<coderef>
7909 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
7910 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
7911 find a glob for this ref.
7913 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
7917 sub CvGV_name_or_bust {
7919 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
7920 return unless ref $in;
7921 $in = \&$in; # Hard reference...
7922 eval { require Devel::Peek; 1 } or return;
7923 my $gv = Devel::Peek::CvGV($in) or return;
7924 *$gv{PACKAGE} . '::' . *$gv{NAME};
7925 } ## end sub CvGV_name_or_bust
7929 A utility routine used in various places; finds the file where a subroutine
7930 was defined, and returns that filename and a line-number range.
7932 Tries to use C<@sub> first; if it can't find it there, it tries building a
7933 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
7934 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
7935 this way, it brute-force searches C<%sub>, checking for identical references.
7942 return unless defined &$subr;
7943 my $name = CvGV_name_or_bust($subr);
7945 $data = $sub{$name} if defined $name;
7946 return $data if defined $data;
7949 $subr = \&$subr; # Hard reference
7952 $s = $_, last if $subr eq \&$_;
7956 } ## end sub find_sub
7960 A subroutine that uses the utility function C<methods_via> to find all the
7961 methods in the class corresponding to the current reference and in
7968 # Figure out the class - either this is the class or it's a reference
7969 # to something blessed into that class.
7971 $class = ref $class if ref $class;
7975 # Show the methods that this class has.
7976 methods_via( $class, '', 1 );
7978 # Show the methods that UNIVERSAL has.
7979 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
7980 } ## end sub methods
7982 =head2 C<methods_via($class, $prefix, $crawl_upward)>
7984 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
7985 all the parent class methods. C<$class> is the name of the next class to
7986 try; C<$prefix> is the message prefix, which gets built up as we go up the
7987 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
7988 higher in the C<@ISA> tree, 0 if we should stop.
7994 # If we've processed this class already, just quit.
7996 return if $seen{$class}++;
7998 # This is a package that is contributing the methods we're about to print.
8000 my $prepend = $prefix ? "via $prefix: " : '';
8003 # Extract from all the symbols in this class.
8004 while (my ($name, $glob) = each %{"${class}::"}) {
8005 # references directly in the symbol table are Proxy Constant
8006 # Subroutines, and are by their very nature defined
8007 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8008 # to a subroutine reference, which can be tested by defined.
8009 # $glob might also be the value -1 (from sub foo;)
8010 # or (say) '$$' (from sub foo ($$);)
8011 # \$glob will be SCALAR in both cases.
8012 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8013 && !$seen{$name}++) {
8014 push @to_print, "$prepend$name\n";
8021 print $DB::OUT $_ foreach sort @to_print;
8024 # If the $crawl_upward argument is false, just quit here.
8025 return unless shift;
8027 # $crawl_upward true: keep going up the tree.
8028 # Find all the classes this one is a subclass of.
8029 for $name ( @{"${class}::ISA"} ) {
8031 # Set up the new prefix.
8032 $prepend = $prefix ? $prefix . " -> $name" : $name;
8034 # Crawl up the tree and keep trying to crawl up.
8035 methods_via( $name, $prepend, 1 );
8037 } ## end sub methods_via
8039 =head2 C<setman> - figure out which command to use to show documentation
8041 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8046 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|MacOS|NetWare)\z/s
8047 ? "man" # O Happy Day!
8048 : "perldoc"; # Alas, poor unfortunates
8051 =head2 C<runman> - run the appropriate command to show documentation
8053 Accepts a man page name; runs the appropriate command to display it (set up
8054 during debugger initialization). Uses C<DB::system> to avoid mucking up the
8055 program's STDIN and STDOUT.
8062 &system("$doccmd $doccmd");
8066 # this way user can override, like with $doccmd="man -Mwhatever"
8067 # or even just "man " to disable the path check.
8068 unless ( $doccmd eq 'man' ) {
8069 &system("$doccmd $page");
8073 $page = 'perl' if lc($page) eq 'help';
8076 my $man1dir = $Config::Config{'man1dir'};
8077 my $man3dir = $Config::Config{'man3dir'};
8078 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8080 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8081 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8082 chop $manpath if $manpath;
8084 # harmless if missing, I figure
8085 my $oldpath = $ENV{MANPATH};
8086 $ENV{MANPATH} = $manpath if $manpath;
8087 my $nopathopt = $^O =~ /dunno what goes here/;
8092 # I just *know* there are men without -M
8093 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8098 unless ( $page =~ /^perl\w/ ) {
8099 # do it this way because its easier to slurp in to keep up to date - clunky though.
8238 if (grep { $page eq $_ } @pods) {
8240 CORE::system( $doccmd,
8241 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8243 } ## end if (grep { $page eq $_...
8244 } ## end unless ($page =~ /^perl\w/)
8245 } ## end if (CORE::system($doccmd...
8246 if ( defined $oldpath ) {
8247 $ENV{MANPATH} = $manpath;
8250 delete $ENV{MANPATH};
8254 #use Carp; # This did break, left for debugging
8256 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
8258 Because of the way the debugger interface to the Perl core is designed, any
8259 debugger package globals that C<DB::sub()> requires have to be defined before
8260 any subroutines can be called. These are defined in the second C<BEGIN> block.
8262 This block sets things up so that (basically) the world is sane
8263 before the debugger starts executing. We set up various variables that the
8264 debugger has to have set up before the Perl core starts running:
8270 The debugger's own filehandles (copies of STD and STDOUT for now).
8274 Characters for shell escapes, the recall command, and the history command.
8278 The maximum recursion depth.
8282 The size of a C<w> command's window.
8286 The before-this-line context to be printed in a C<v> (view a window around this line) command.
8290 The fact that we're not in a sub at all right now.
8294 The default SIGINT handler for the debugger.
8298 The appropriate value of the flag in C<$^D> that says the debugger is running
8302 The current debugger recursion level
8306 The list of postponed items and the C<$single> stack (XXX define this)
8310 That we want no return values and no subroutine entry/exit trace.
8316 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
8318 BEGIN { # This does not compile, alas. (XXX eh?)
8319 $IN = \*STDIN; # For bugs before DB::OUT has been opened
8320 $OUT = \*STDERR; # For errors before DB::OUT has been opened
8322 # Define characters used by command parsing.
8323 $sh = '!'; # Shell escape (does not work)
8324 $rc = ','; # Recall command (does not work)
8325 @hist = ('?'); # Show history (does not work)
8326 @truehist = (); # Can be saved for replay (per session)
8328 # This defines the point at which you get the 'deep recursion'
8329 # warning. It MUST be defined or the debugger will not load.
8332 # Number of lines around the current one that are shown in the
8336 # How much before-the-current-line context the 'v' command should
8337 # use in calculating the start of the window it will display.
8340 # We're not in any sub yet, but we need this to be a defined value.
8343 # Set up the debugger's interrupt handler. It simply sets a flag
8344 # ($signal) that DB::DB() will check before each command is executed.
8345 $SIG{INT} = \&DB::catch;
8347 # The following lines supposedly, if uncommented, allow the debugger to
8348 # debug itself. Perhaps we can try that someday.
8349 # This may be enabled to debug debugger:
8350 #$warnLevel = 1 unless defined $warnLevel;
8351 #$dieLevel = 1 unless defined $dieLevel;
8352 #$signalLevel = 1 unless defined $signalLevel;
8354 # This is the flag that says "a debugger is running, please call
8355 # DB::DB and DB::sub". We will turn it on forcibly before we try to
8356 # execute anything in the user's context, because we always want to
8358 $db_stop = 0; # Compiler warning ...
8359 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
8361 # This variable records how many levels we're nested in debugging. Used
8362 # Used in the debugger prompt, and in determining whether it's all over or
8364 $level = 0; # Level of recursive debugging
8366 # "Triggers bug (?) in perl if we postpone this until runtime."
8367 # XXX No details on this yet, or whether we should fix the bug instead
8368 # of work around it. Stay tuned.
8369 @postponed = @stack = (0);
8371 # Used to track the current stack depth using the auto-stacked-variable
8373 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
8375 # Don't print return values on exiting a subroutine.
8378 # No extry/exit tracing.
8383 BEGIN { $^W = $ini_warn; } # Switch warnings back
8385 =head1 READLINE SUPPORT - COMPLETION FUNCTION
8389 C<readline> support - adds command completion to basic C<readline>.
8391 Returns a list of possible completions to C<readline> when invoked. C<readline>
8392 will print the longest common substring following the text already entered.
8394 If there is only a single possible completion, C<readline> will use it in full.
8396 This code uses C<map> and C<grep> heavily to create lists of possible
8397 completion. Think LISP in this section.
8403 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
8404 # $text is the text to be completed.
8405 # $line is the incoming line typed by the user.
8406 # $start is the start of the text to be completed in the incoming line.
8407 my ( $text, $line, $start ) = @_;
8409 # Save the initial text.
8410 # The search pattern is current package, ::, extract the next qualifier
8411 # Prefix and pack are set to undef.
8412 my ( $itext, $search, $prefix, $pack ) =
8413 ( $text, "^\Q${'package'}::\E([^:]+)\$" );
8415 =head3 C<b postpone|compile>
8421 Find all the subroutines that might match in this package
8425 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
8429 Include all the rest of the subs that are known
8433 C<grep> out the ones that match the text we have so far
8437 Return this as the list of possible completions
8443 return sort grep /^\Q$text/, ( keys %sub ),
8444 qw(postpone load compile), # subroutines
8445 ( map { /$search/ ? ($1) : () } keys %sub )
8446 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
8450 Get all the possible files from C<@INC> as it currently stands and
8451 select the ones that match the text so far.
8455 return sort grep /^\Q$text/, values %INC # files
8456 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
8458 =head3 C<V> (list variable) and C<m> (list modules)
8460 There are two entry points for these commands:
8462 =head4 Unqualified package names
8464 Get the top-level packages and grab everything that matches the text
8465 so far. For each match, recursively complete the partial packages to
8466 get all possible matching packages. Return this sorted list.
8470 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8471 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
8472 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
8474 =head4 Qualified package names
8476 Take a partially-qualified package and find all subpackages for it
8477 by getting all the subpackages for the package so far, matching all
8478 the subpackages against the text, and discarding all of them which
8479 start with 'main::'. Return this list.
8483 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8484 grep !/^main::/, grep /^\Q$text/,
8485 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () } keys %{ $prefix . '::' }
8486 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
8487 and $text =~ /^(.*[^:])::?(\w*)$/
8490 =head3 C<f> - switch files
8492 Here, we want to get a fully-qualified filename for the C<f> command.
8497 =item 1. The original source file itself
8499 =item 2. A file from C<@INC>
8501 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
8507 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
8508 # We might possibly want to switch to an eval (which has a "filename"
8509 # like '(eval 9)'), so we may need to clean up the completion text
8510 # before proceeding.
8511 $prefix = length($1) - length($text);
8516 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
8517 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
8518 out of C<%main::>, add the initial source file, and extract the ones that
8519 match the completion text so far.
8524 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
8526 } ## end if ($line =~ /^\|*f\s+(.*)/)
8528 =head3 Subroutine name completion
8530 We look through all of the defined subs (the keys of C<%sub>) and
8531 return both all the possible matches to the subroutine name plus
8532 all the matches qualified to the current package.
8536 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
8537 $text = substr $text, 1;
8539 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
8541 map { /$search/ ? ($1) : () }
8544 } ## end if ((substr $text, 0, ...
8546 =head3 Scalar, array, and hash completion: partially qualified package
8548 Much like the above, except we have to do a little more cleanup:
8552 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
8560 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
8564 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
8570 Figure out the prefix vs. what needs completing.
8574 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
8581 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
8585 my @out = map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
8592 If there's only one hit, and it's a package qualifier, and it's not equal to the initial text, re-complete it using the symbol we actually found.
8596 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8597 return db_complete( $out[0], $line, $start );
8600 # Return the list of possibles.
8603 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
8609 =head3 Symbol completion: current package or package C<main>.
8613 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
8621 If it's C<main>, delete main to just get C<::> leading.
8625 $pack = ( $package eq 'main' ? '' : $package ) . '::';
8631 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
8635 $prefix = substr $text, 0, 1;
8636 $text = substr $text, 1;
8642 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
8646 my @out = map "$prefix$_", grep /^\Q$text/,
8647 ( grep /^_?[a-zA-Z]/, keys %$pack ),
8648 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
8652 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
8658 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8659 return db_complete( $out[0], $line, $start );
8662 # Return the list of possibles.
8664 } ## end if ($text =~ /^[\$@%]/)
8668 We use C<option_val()> to look up the current value of the option. If there's
8669 only a single value, we complete the command in such a way that it is a
8670 complete command for setting the option in question. If there are multiple
8671 possible values, we generate a command consisting of the option plus a trailing
8672 question mark, which, if executed, will list the current value of the option.
8676 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
8677 { # Options after space
8678 # We look for the text to be matched in the list of possible options,
8679 # and fetch the current value.
8680 my @out = grep /^\Q$text/, @options;
8681 my $val = option_val( $out[0], undef );
8683 # Set up a 'query option's value' command.
8685 if ( not defined $val or $val =~ /[\n\r]/ ) {
8687 # There's really nothing else we can do.
8690 # We have a value. Create a proper option-setting command.
8691 elsif ( $val =~ /\s/ ) {
8693 # XXX This may be an extraneous variable.
8696 # We'll want to quote the string (because of the embedded
8697 # whtespace), but we want to make sure we don't end up with
8698 # mismatched quote characters. We try several possibilities.
8699 foreach $l ( split //, qq/\"\'\#\|/ ) {
8701 # If we didn't find this quote character in the value,
8702 # quote it using this quote character.
8703 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
8705 } ## end elsif ($val =~ /\s/)
8707 # Don't need any quotes.
8712 # If there were multiple possible values, return '? ', which
8713 # makes the command into a query command. If there was just one,
8714 # have readline append that.
8715 $rl_attribs->{completer_terminator_character} =
8716 ( @out == 1 ? $out : '? ' );
8718 # Return list of possibilities.
8720 } ## end if ((substr $line, 0, ...
8722 =head3 Filename completion
8724 For entering filenames. We simply call C<readline>'s C<filename_list()>
8725 method with the completion text to get the possible completions.
8729 return $term->filename_list($text); # filenames
8731 } ## end sub db_complete
8733 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
8735 Functions that possibly ought to be somewhere else.
8745 print $OUT "Use `q' to quit or `R' to restart. `h q' for details.\n";
8750 If we have $ini_pids, save it in the environment; else remove it from the
8751 environment. Used by the C<R> (restart) command.
8756 if ( defined($ini_pids) ) {
8757 $ENV{PERLDB_PIDS} = $ini_pids;
8760 delete( $ENV{PERLDB_PIDS} );
8762 } ## end sub clean_ENV
8764 # PERLDBf_... flag names from perl.h
8765 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
8768 %DollarCaretP_flags = (
8769 PERLDBf_SUB => 0x01, # Debug sub enter/exit
8770 PERLDBf_LINE => 0x02, # Keep line #
8771 PERLDBf_NOOPT => 0x04, # Switch off optimizations
8772 PERLDBf_INTER => 0x08, # Preserve more data
8773 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
8774 PERLDBf_SINGLE => 0x20, # Start with single-step on
8775 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
8776 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
8777 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
8778 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
8779 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
8780 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
8782 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
8783 # doesn't need to set it. It's provided for the benefit of profilers and
8784 # other code analysers.
8786 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
8789 sub parse_DollarCaretP_flags {
8794 foreach my $f ( split /\s*\|\s*/, $flags ) {
8796 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
8799 elsif ( $f =~ /^(\d+)$/ ) {
8802 elsif ( $f =~ /^DEFAULT$/i ) {
8803 $value = $DollarCaretP_flags{PERLDB_ALL};
8806 $f =~ /^(?:PERLDBf_)?(.*)$/i;
8807 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
8808 unless ( defined $value ) {
8810 "Unrecognized \$^P flag '$f'!\n",
8811 "Acceptable flags are: "
8812 . join( ', ', sort keys %DollarCaretP_flags ),
8813 ", and hexadecimal and decimal numbers.\n"
8823 sub expand_DollarCaretP_flags {
8824 my $DollarCaretP = shift;
8827 my $n = ( 1 << $_ );
8828 ( $DollarCaretP & $n )
8829 ? ( $DollarCaretP_flags_r{$n}
8830 || sprintf( '0x%x', $n ) )
8834 return @bits ? join( '|', @bits ) : 0;
8841 Rerun the current session to:
8843 rerun current position
8845 rerun 4 command number 4
8847 rerun -4 current command minus 4 (go back 4 steps)
8849 Whether this always makes sense, in the current context is unknowable, and is
8850 in part left as a useful exersize for the reader. This sub returns the
8851 appropriate arguments to rerun the current session.
8858 pop(@truehist); # strim
8859 unless (defined $truehist[$i]) {
8860 print "Unable to return to non-existent command: $i\n";
8862 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
8863 my @temp = @truehist; # store
8864 push(@DB::typeahead, @truehist); # saved
8865 @truehist = @hist = (); # flush
8866 @args = &restart(); # setup
8867 &get_list("PERLDB_HIST"); # clean
8868 &set_list("PERLDB_HIST", @temp); # reset
8875 Restarting the debugger is a complex operation that occurs in several phases.
8876 First, we try to reconstruct the command line that was used to invoke Perl
8882 # I may not be able to resurrect you, but here goes ...
8884 "Warning: some settings and command-line options may be lost!\n";
8885 my ( @script, @flags, $cl );
8887 # If warn was on before, turn it on again.
8888 push @flags, '-w' if $ini_warn;
8890 # Rebuild the -I flags that were on the initial
8893 push @flags, '-I', $_;
8896 # Turn on taint if it was on before.
8897 push @flags, '-T' if ${^TAINT};
8899 # Arrange for setting the old INC:
8900 # Save the current @init_INC in the environment.
8901 set_list( "PERLDB_INC", @ini_INC );
8903 # If this was a perl one-liner, go to the "file"
8904 # corresponding to the one-liner read all the lines
8905 # out of it (except for the first one, which is going
8906 # to be added back on again when 'perl -d' runs: that's
8907 # the 'require perl5db.pl;' line), and add them back on
8908 # to the command line to be executed.
8910 for ( 1 .. $#{'::_<-e'} ) { # The first line is PERL5DB
8911 chomp( $cl = ${'::_<-e'}[$_] );
8912 push @script, '-e', $cl;
8914 } ## end if ($0 eq '-e')
8916 # Otherwise we just reuse the original name we had
8924 After the command line has been reconstructed, the next step is to save
8925 the debugger's status in environment variables. The C<DB::set_list> routine
8926 is used to save aggregate variables (both hashes and arrays); scalars are
8927 just popped into environment variables directly.
8931 # If the terminal supported history, grab it and
8932 # save that in the environment.
8933 set_list( "PERLDB_HIST",
8934 $term->Features->{getHistory}
8938 # Find all the files that were visited during this
8939 # session (i.e., the debugger had magic hashes
8940 # corresponding to them) and stick them in the environment.
8941 my @had_breakpoints = keys %had_breakpoints;
8942 set_list( "PERLDB_VISITED", @had_breakpoints );
8944 # Save the debugger options we chose.
8945 set_list( "PERLDB_OPT", %option );
8946 # set_list( "PERLDB_OPT", options2remember() );
8948 # Save the break-on-loads.
8949 set_list( "PERLDB_ON_LOAD", %break_on_load );
8953 The most complex part of this is the saving of all of the breakpoints. They
8954 can live in an awful lot of places, and we have to go through all of them,
8955 find the breakpoints, and then save them in the appropriate environment
8956 variable via C<DB::set_list>.
8960 # Go through all the breakpoints and make sure they're
8963 for ( 0 .. $#had_breakpoints ) {
8965 # We were in this file.
8966 my $file = $had_breakpoints[$_];
8968 # Grab that file's magic line hash.
8969 *dbline = $main::{ '_<' . $file };
8971 # Skip out if it doesn't exist, or if the breakpoint
8972 # is in a postponed file (we'll do postponed ones
8974 next unless %dbline or $postponed_file{$file};
8976 # In an eval. This is a little harder, so we'll
8977 # do more processing on that below.
8978 ( push @hard, $file ), next
8979 if $file =~ /^\(\w*eval/;
8981 # XXX I have no idea what this is doing. Yet.
8983 @add = %{ $postponed_file{$file} }
8984 if $postponed_file{$file};
8986 # Save the list of all the breakpoints for this file.
8987 set_list( "PERLDB_FILE_$_", %dbline, @add );
8988 } ## end for (0 .. $#had_breakpoints)
8990 # The breakpoint was inside an eval. This is a little
8991 # more difficult. XXX and I don't understand it.
8993 # Get over to the eval in question.
8994 *dbline = $main::{ '_<' . $_ };
8995 my ( $quoted, $sub, %subs, $line ) = quotemeta $_;
8996 for $sub ( keys %sub ) {
8997 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
8998 $subs{$sub} = [ $1, $2 ];
9002 "No subroutines in $_, ignoring breakpoints.\n";
9005 LINES: for $line ( keys %dbline ) {
9007 # One breakpoint per sub only:
9008 my ( $offset, $sub, $found );
9009 SUBS: for $sub ( keys %subs ) {
9012 $line # Not after the subroutine
9014 not defined $offset # Not caught
9020 $offset = $line - $subs{$sub}->[0];
9021 $offset = "+$offset", last SUBS
9023 } ## end if ($subs{$sub}->[1] >=...
9024 } ## end for $sub (keys %subs)
9025 if ( defined $offset ) {
9026 $postponed{$found} =
9027 "break $offset if $dbline{$line}";
9031 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
9033 } ## end for $line (keys %dbline)
9034 } ## end for (@hard)
9036 # Save the other things that don't need to be
9038 set_list( "PERLDB_POSTPONE", %postponed );
9039 set_list( "PERLDB_PRETYPE", @$pretype );
9040 set_list( "PERLDB_PRE", @$pre );
9041 set_list( "PERLDB_POST", @$post );
9042 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9044 # We are oficially restarting.
9045 $ENV{PERLDB_RESTART} = 1;
9047 # We are junking all child debuggers.
9048 delete $ENV{PERLDB_PIDS}; # Restore ini state
9050 # Set this back to the initial pid.
9051 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9055 After all the debugger status has been saved, we take the command we built up
9056 and then return it, so we can C<exec()> it. The debugger will spot the
9057 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9058 from the environment.
9062 # And run Perl again. Add the "-d" flag, all the
9063 # flags we built up, the script (whether a one-liner
9064 # or a file), add on the -emacs flag for a slave editor,
9065 # and then the old arguments.
9067 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9073 =head1 END PROCESSING - THE C<END> BLOCK
9075 Come here at the very end of processing. We want to go into a
9076 loop where we allow the user to enter commands and interact with the
9077 debugger, but we don't want anything else to execute.
9079 First we set the C<$finished> variable, so that some commands that
9080 shouldn't be run after the end of program quit working.
9082 We then figure out whether we're truly done (as in the user entered a C<q>
9083 command, or we finished execution while running nonstop). If we aren't,
9084 we set C<$single> to 1 (causing the debugger to get control again).
9086 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9087 message and returns control to the debugger. Repeat.
9089 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9090 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9091 break, run to completion.).
9096 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9097 $fall_off_end = 1 unless $inhibit_exit;
9099 # Do not stop in at_exit() and destructors on exit:
9100 if ($fall_off_end or $runnonstop) {
9104 DB::fake::at_exit();
9108 =head1 PRE-5.8 COMMANDS
9110 Some of the commands changed function quite a bit in the 5.8 command
9111 realignment, so much so that the old code had to be replaced completely.
9112 Because we wanted to retain the option of being able to go back to the
9113 former command set, we moved the old code off to this section.
9115 There's an awful lot of duplicated code here. We've duplicated the
9116 comments to keep things clear.
9120 Does nothing. Used to I<turn off> commands.
9124 sub cmd_pre580_null {
9129 =head2 Old C<a> command.
9131 This version added actions if you supplied them, and deleted them
9140 # Argument supplied. Add the action.
9141 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9143 # If the line isn't there, use the current line.
9147 # If there is an action ...
9150 # ... but the line isn't breakable, skip it.
9151 if ( $dbline[$i] == 0 ) {
9152 print $OUT "Line $i may not have an action.\n";
9156 # ... and the line is breakable:
9157 # Mark that there's an action in this file.
9158 $had_breakpoints{$filename} |= 2;
9160 # Delete any current action.
9161 $dbline{$i} =~ s/\0[^\0]*//;
9163 # Add the new action, continuing the line as needed.
9164 $dbline{$i} .= "\0" . action($j);
9166 } ## end if (length $j)
9168 # No action supplied.
9171 # Delete the action.
9172 $dbline{$i} =~ s/\0[^\0]*//;
9174 # Mark as having no break or action if nothing's left.
9175 delete $dbline{$i} if $dbline{$i} eq '';
9177 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9178 } ## end sub cmd_pre580_a
9180 =head2 Old C<b> command
9192 if ( $cmd =~ /^load\b\s*(.*)/ ) {
9198 # b compile|postpone <some sub> [<condition>]
9199 # The interpreter actually traps this one for us; we just put the
9200 # necessary condition in the %postponed hash.
9201 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
9203 # Capture the condition if there is one. Make it true if none.
9204 my $cond = length $3 ? $3 : '1';
9206 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
9207 # if it was 'compile'.
9208 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
9210 # De-Perl4-ify the name - ' separators to ::.
9211 $subname =~ s/\'/::/g;
9213 # Qualify it into the current package unless it's already qualified.
9214 $subname = "${'package'}::" . $subname
9215 unless $subname =~ /::/;
9217 # Add main if it starts with ::.
9218 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
9220 # Save the break type for this sub.
9221 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
9222 } ## end elsif ($cmd =~ ...
9224 # b <sub name> [<condition>]
9225 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
9227 my $cond = length $2 ? $2 : '1';
9228 &cmd_b_sub( $subname, $cond );
9231 # b <line> [<condition>].
9232 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9233 my $i = $1 || $dbline;
9234 my $cond = length $2 ? $2 : '1';
9235 &cmd_b_line( $i, $cond );
9237 } ## end sub cmd_pre580_b
9239 =head2 Old C<D> command.
9241 Delete all breakpoints unconditionally.
9248 if ( $cmd =~ /^\s*$/ ) {
9249 print $OUT "Deleting all breakpoints...\n";
9251 # %had_breakpoints lists every file that had at least one
9254 for $file ( keys %had_breakpoints ) {
9256 # Switch to the desired file temporarily.
9257 local *dbline = $main::{ '_<' . $file };
9262 # For all lines in this file ...
9263 for ( $i = 1 ; $i <= $max ; $i++ ) {
9265 # If there's a breakpoint or action on this line ...
9266 if ( defined $dbline{$i} ) {
9268 # ... remove the breakpoint.
9269 $dbline{$i} =~ s/^[^\0]+//;
9270 if ( $dbline{$i} =~ s/^\0?$// ) {
9272 # Remove the entry altogether if no action is there.
9275 } ## end if (defined $dbline{$i...
9276 } ## end for ($i = 1 ; $i <= $max...
9278 # If, after we turn off the "there were breakpoints in this file"
9279 # bit, the entry in %had_breakpoints for this file is zero,
9280 # we should remove this file from the hash.
9281 if ( not $had_breakpoints{$file} &= ~1 ) {
9282 delete $had_breakpoints{$file};
9284 } ## end for $file (keys %had_breakpoints)
9286 # Kill off all the other breakpoints that are waiting for files that
9287 # haven't been loaded yet.
9289 undef %postponed_file;
9290 undef %break_on_load;
9291 } ## end if ($cmd =~ /^\s*$/)
9292 } ## end sub cmd_pre580_D
9294 =head2 Old C<h> command
9296 Print help. Defaults to printing the long-form help; the 5.8 version
9297 prints the summary by default.
9305 # Print the *right* help, long format.
9306 if ( $cmd =~ /^\s*$/ ) {
9307 print_help($pre580_help);
9310 # 'h h' - explicitly-requested summary.
9311 elsif ( $cmd =~ /^h\s*/ ) {
9312 print_help($pre580_summary);
9315 # Find and print a command's help.
9316 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
9317 my $asked = $1; # for proper errmsg
9318 my $qasked = quotemeta($asked); # for searching
9319 # XXX: finds CR but not <CR>
9323 (?:[IB]<) # Optional markup
9324 $qasked # The command name
9331 ( # The command help:
9333 (?:[IB]<) # Optional markup
9334 $qasked # The command name
9335 ([\s\S]*?) # Lines starting with tabs
9339 ) # Line not starting with space
9340 # (Next command's help)
9344 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
9348 print_help("B<$asked> is not a debugger command.\n");
9350 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
9351 } ## end sub cmd_pre580_h
9353 =head2 Old C<W> command
9355 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
9363 # Delete all watch expressions.
9364 if ( $cmd =~ /^$/ ) {
9366 # No watching is going on.
9369 # Kill all the watch expressions and values.
9370 @to_watch = @old_watch = ();
9373 # Add a watch expression.
9374 elsif ( $cmd =~ /^(.*)/s ) {
9376 # add it to the list to be watched.
9379 # Get the current value of the expression.
9380 # Doesn't handle expressions returning list values!
9383 $val = ( defined $val ) ? "'$val'" : 'undef';
9386 push @old_watch, $val;
9388 # We're watching stuff.
9391 } ## end elsif ($cmd =~ /^(.*)/s)
9392 } ## end sub cmd_pre580_W
9394 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
9396 The debugger used to have a bunch of nearly-identical code to handle
9397 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
9398 C<cmd_prepost> unify all this into one set of code to handle the
9399 appropriate actions.
9401 =head2 C<cmd_pre590_prepost>
9403 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
9404 do something destructive. In pre 5.8 debuggers, the default action was to
9405 delete all the actions.
9409 sub cmd_pre590_prepost {
9411 my $line = shift || '*';
9414 return &cmd_prepost( $cmd, $line, $dbline );
9415 } ## end sub cmd_pre590_prepost
9417 =head2 C<cmd_prepost>
9419 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
9420 Since the lists of actions are all held in arrays that are pointed to by
9421 references anyway, all we have to do is pick the right array reference and
9422 then use generic code to all, delete, or list actions.
9429 # No action supplied defaults to 'list'.
9430 my $line = shift || '?';
9432 # Figure out what to put in the prompt.
9435 # Make sure we have some array or another to address later.
9436 # This means that if ssome reason the tests fail, we won't be
9437 # trying to stash actions or delete them from the wrong place.
9440 # < - Perl code to run before prompt.
9441 if ( $cmd =~ /^\</o ) {
9442 $which = 'pre-perl';
9446 # > - Perl code to run after prompt.
9447 elsif ( $cmd =~ /^\>/o ) {
9448 $which = 'post-perl';
9452 # { - first check for properly-balanced braces.
9453 elsif ( $cmd =~ /^\{/o ) {
9454 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
9456 "$cmd is now a debugger command\nuse `;$cmd' if you mean Perl code\n";
9459 # Properly balanced. Pre-prompt debugger actions.
9461 $which = 'pre-debugger';
9464 } ## end elsif ( $cmd =~ /^\{/o )
9466 # Did we find something that makes sense?
9468 print $OUT "Confused by command: $cmd\n";
9475 if ( $line =~ /^\s*\?\s*$/o ) {
9478 # Nothing there. Complain.
9479 print $OUT "No $which actions.\n";
9483 # List the actions in the selected list.
9484 print $OUT "$which commands:\n";
9485 foreach my $action (@$aref) {
9486 print $OUT "\t$cmd -- $action\n";
9489 } ## end if ( $line =~ /^\s*\?\s*$/o)
9491 # Might be a delete.
9493 if ( length($cmd) == 1 ) {
9494 if ( $line =~ /^\s*\*\s*$/o ) {
9496 # It's a delete. Get rid of the old actions in the
9499 print $OUT "All $cmd actions cleared.\n";
9503 # Replace all the actions. (This is a <, >, or {).
9504 @$aref = action($line);
9506 } ## end if ( length($cmd) == 1)
9507 elsif ( length($cmd) == 2 ) {
9509 # Add the action to the line. (This is a <<, >>, or {{).
9510 push @$aref, action($line);
9514 # <<<, >>>>, {{{{{{ ... something not a command.
9516 "Confused by strange length of $which command($cmd)...\n";
9518 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
9520 } ## end sub cmd_prepost
9524 Contains the C<at_exit> routine that the debugger uses to issue the
9525 C<Debugged program terminated ...> message after the program completes. See
9526 the C<END> block documentation for more details.
9533 "Debugged program terminated. Use `q' to quit or `R' to restart.";
9536 package DB; # Do not trace this 1; below!