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
944 ########################################################################
946 =head1 DEBUGGER INITIALIZATION
948 The debugger starts up in phases.
952 First, it initializes the environment it wants to run in: turning off
953 warnings during its own compilation, defining variables which it will need
954 to avoid warnings later, setting itself up to not exit when the program
955 terminates, and defaulting to printing return values for the C<r> command.
959 # Needed for the statement after exec():
961 # This BEGIN block is simply used to switch off warnings during debugger
962 # compiliation. Probably it would be better practice to fix the warnings,
963 # but this is how it's done at the moment.
968 } # Switch compilation warnings off until another BEGIN.
970 # test if assertions are supported and actived:
972 $ini_assertion = eval "sub asserting_test : assertion {1}; 1";
974 # $ini_assertion = undef => assertions unsupported,
975 # " = 1 => assertions supported
976 # print "\$ini_assertion=$ini_assertion\n";
979 local ($^W) = 0; # Switch run-time warnings off during init.
981 =head2 THREADS SUPPORT
983 If we are running under a threaded Perl, we require threads and threads::shared
984 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
985 threaded debugger control. C<-dt> can also be used to set this.
987 Each new thread will be announced and the debugger prompt will always inform
988 you of each new thread created. It will also indicate the thread id in which
989 we are currently running within the prompt like this:
993 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
994 command prompt. The prompt will show: C<[0]> when running under threads, but
995 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
997 While running under threads, when you set or delete a breakpoint (etc.), this
998 will apply to all threads, not just the currently running one. When you are
999 in a currently executing thread, you will stay there until it completes. With
1000 the current implementation it is not currently possible to hop from one thread
1003 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
1005 Note that threading support was built into the debugger as of Perl version
1006 C<5.8.6> and debugger version C<1.2.8>.
1011 # ensure we can share our non-threaded variables or no-op
1012 if ($ENV{PERL5DB_THREADED}) {
1014 require threads::shared;
1015 import threads::shared qw(share);
1019 print "Threads support enabled\n";
1026 # This would probably be better done with "use vars", but that wasn't around
1027 # when this code was originally written. (Neither was "use strict".) And on
1028 # the principle of not fiddling with something that was working, this was
1031 # These variables control the execution of 'dumpvar.pl'.
1032 $dumpvar::hashDepth,
1033 $dumpvar::arrayDepth,
1034 $dumpvar::dumpDBFiles,
1035 $dumpvar::dumpPackages,
1036 $dumpvar::quoteHighBit,
1037 $dumpvar::printUndef,
1038 $dumpvar::globPrint,
1039 $dumpvar::usageOnly,
1041 # used to save @ARGV and extract any debugger-related flags.
1044 # used to control die() reporting in diesignal()
1047 # used to prevent multiple entries to diesignal()
1048 # (if for instance diesignal() itself dies)
1051 # used to prevent the debugger from running nonstop
1057 foreach my $k (keys (%INC)) {
1058 &share(\$main::{'_<'.$filename});
1061 # Command-line + PERLLIB:
1062 # Save the contents of @INC before they are modified elsewhere.
1065 # This was an attempt to clear out the previous values of various
1066 # trapped errors. Apparently it didn't help. XXX More info needed!
1067 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
1069 # We set these variables to safe values. We don't want to blindly turn
1070 # off warnings, because other packages may still want them.
1071 $trace = $signal = $single = 0; # Uninitialized warning suppression
1072 # (local $^W cannot help - other packages!).
1074 # Default to not exiting when program finishes; print the return
1075 # value when the 'r' command is used to return from a subroutine.
1076 $inhibit_exit = $option{PrintRet} = 1;
1078 =head1 OPTION PROCESSING
1080 The debugger's options are actually spread out over the debugger itself and
1081 C<dumpvar.pl>; some of these are variables to be set, while others are
1082 subs to be called with a value. To try to make this a little easier to
1083 manage, the debugger uses a few data structures to define what options
1084 are legal and how they are to be processed.
1086 First, the C<@options> array defines the I<names> of all the options that
1092 CommandSet HistFile HistSize
1093 hashDepth arrayDepth dumpDepth
1094 DumpDBFiles DumpPackages DumpReused
1095 compactDump veryCompact quote
1096 HighBit undefPrint globPrint
1097 PrintRet UsageOnly frame
1099 ReadLine NonStop LineInfo
1100 maxTraceLen recallCommand ShellBang
1101 pager tkRunning ornaments
1102 signalLevel warnLevel dieLevel
1103 inhibit_exit ImmediateStop bareStringify
1104 CreateTTY RemotePort windowSize
1105 DollarCaretP OnlyAssertions WarnAssertions
1108 @RememberOnROptions = qw(DollarCaretP OnlyAssertions);
1112 Second, C<optionVars> lists the variables that each option uses to save its
1118 hashDepth => \$dumpvar::hashDepth,
1119 arrayDepth => \$dumpvar::arrayDepth,
1120 CommandSet => \$CommandSet,
1121 DumpDBFiles => \$dumpvar::dumpDBFiles,
1122 DumpPackages => \$dumpvar::dumpPackages,
1123 DumpReused => \$dumpvar::dumpReused,
1124 HighBit => \$dumpvar::quoteHighBit,
1125 undefPrint => \$dumpvar::printUndef,
1126 globPrint => \$dumpvar::globPrint,
1127 UsageOnly => \$dumpvar::usageOnly,
1128 CreateTTY => \$CreateTTY,
1129 bareStringify => \$dumpvar::bareStringify,
1131 AutoTrace => \$trace,
1132 inhibit_exit => \$inhibit_exit,
1133 maxTraceLen => \$maxtrace,
1134 ImmediateStop => \$ImmediateStop,
1135 RemotePort => \$remoteport,
1136 windowSize => \$window,
1137 WarnAssertions => \$warnassertions,
1138 HistFile => \$histfile,
1139 HistSize => \$histsize,
1144 Third, C<%optionAction> defines the subroutine to be called to process each
1150 compactDump => \&dumpvar::compactDump,
1151 veryCompact => \&dumpvar::veryCompact,
1152 quote => \&dumpvar::quote,
1155 ReadLine => \&ReadLine,
1156 NonStop => \&NonStop,
1157 LineInfo => \&LineInfo,
1158 recallCommand => \&recallCommand,
1159 ShellBang => \&shellBang,
1161 signalLevel => \&signalLevel,
1162 warnLevel => \&warnLevel,
1163 dieLevel => \&dieLevel,
1164 tkRunning => \&tkRunning,
1165 ornaments => \&ornaments,
1166 RemotePort => \&RemotePort,
1167 DollarCaretP => \&DollarCaretP,
1168 OnlyAssertions=> \&OnlyAssertions,
1173 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1178 # Note that this list is not complete: several options not listed here
1179 # actually require that dumpvar.pl be loaded for them to work, but are
1180 # not in the table. A subsequent patch will correct this problem; for
1181 # the moment, we're just recommenting, and we are NOT going to change
1184 compactDump => 'dumpvar.pl',
1185 veryCompact => 'dumpvar.pl',
1186 quote => 'dumpvar.pl',
1191 There are a number of initialization-related variables which can be set
1192 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1193 variable. These are:
1197 =item C<$rl> - readline control XXX needs more explanation
1199 =item C<$warnLevel> - whether or not debugger takes over warning handling
1201 =item C<$dieLevel> - whether or not debugger takes over die handling
1203 =item C<$signalLevel> - whether or not debugger takes over signal handling
1205 =item C<$pre> - preprompt actions (array reference)
1207 =item C<$post> - postprompt actions (array reference)
1211 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1213 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1219 # These guys may be defined in $ENV{PERL5DB} :
1220 $rl = 1 unless defined $rl;
1221 $warnLevel = 1 unless defined $warnLevel;
1222 $dieLevel = 1 unless defined $dieLevel;
1223 $signalLevel = 1 unless defined $signalLevel;
1224 $pre = [] unless defined $pre;
1225 $post = [] unless defined $post;
1226 $pretype = [] unless defined $pretype;
1227 $CreateTTY = 3 unless defined $CreateTTY;
1228 $CommandSet = '580' unless defined $CommandSet;
1233 share($signalLevel);
1243 The default C<die>, C<warn>, and C<signal> handlers are set up.
1247 warnLevel($warnLevel);
1248 dieLevel($dieLevel);
1249 signalLevel($signalLevel);
1253 The pager to be used is needed next. We try to get it from the
1254 environment first. If it's not defined there, we try to find it in
1255 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1256 then call the C<pager()> function to save the pager name.
1260 # This routine makes sure $pager is set up so that '|' can use it.
1263 # If PAGER is defined in the environment, use it.
1267 # If not, see if Config.pm defines it.
1268 : eval { require Config }
1269 && defined $Config::Config{pager}
1270 ? $Config::Config{pager}
1272 # If not, fall back to 'more'.
1275 unless defined $pager;
1279 We set up the command to be used to access the man pages, the command
1280 recall character (C<!> unless otherwise defined) and the shell escape
1281 character (C<!> unless otherwise defined). Yes, these do conflict, and
1282 neither works in the debugger at the moment.
1288 # Set up defaults for command recall and shell escape (note:
1289 # these currently don't work in linemode debugging).
1290 &recallCommand("!") unless defined $prc;
1291 &shellBang("!") unless defined $psh;
1295 We then set up the gigantic string containing the debugger help.
1296 We also set the limit on the number of arguments we'll display during a
1303 # If we didn't get a default for the length of eval/stack trace args,
1305 $maxtrace = 400 unless defined $maxtrace;
1307 =head2 SETTING UP THE DEBUGGER GREETING
1309 The debugger I<greeting> helps to inform the user how many debuggers are
1310 running, and whether the current debugger is the primary or a child.
1312 If we are the primary, we just hang onto our pid so we'll have it when
1313 or if we start a child debugger. If we are a child, we'll set things up
1314 so we'll have a unique greeting and so the parent will give us our own
1317 We save the current contents of the C<PERLDB_PIDS> environment variable
1318 because we mess around with it. We'll also need to hang onto it because
1319 we'll need it if we restart.
1321 Child debuggers make a label out of the current PID structure recorded in
1322 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1323 yet so the parent will give them one later via C<resetterm()>.
1327 # Save the current contents of the environment; we're about to
1328 # much with it. We'll need this if we have to restart.
1329 $ini_pids = $ENV{PERLDB_PIDS};
1331 if ( defined $ENV{PERLDB_PIDS} ) {
1333 # We're a child. Make us a label out of the current PID structure
1334 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1335 # a term yet so the parent will give us one later via resetterm().
1337 my $env_pids = $ENV{PERLDB_PIDS};
1338 $pids = "[$env_pids]";
1340 # Unless we are on OpenVMS, all programs under the DCL shell run under
1343 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1347 $ENV{PERLDB_PIDS} .= "->$$";
1351 } ## end if (defined $ENV{PERLDB_PIDS...
1354 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1355 # child debugger, and mark us as the parent, so we'll know to set up
1356 # more TTY's is we have to.
1357 $ENV{PERLDB_PIDS} = "$$";
1364 # Sets up $emacs as a synonym for $slave_editor.
1365 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1367 =head2 READING THE RC FILE
1369 The debugger will read a file of initialization options if supplied. If
1370 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1374 # As noted, this test really doesn't check accurately that the debugger
1375 # is running at a terminal or not.
1377 if ( -e "/dev/tty" ) { # this is the wrong metric!
1378 $rcfile = ".perldb";
1381 $rcfile = "perldb.ini";
1386 The debugger does a safety test of the file to be read. It must be owned
1387 either by the current user or root, and must only be writable by the owner.
1391 # This wraps a safety test around "do" to read and evaluate the init file.
1393 # This isn't really safe, because there's a race
1394 # between checking and opening. The solution is to
1395 # open and fstat the handle, but then you have to read and
1396 # eval the contents. But then the silly thing gets
1397 # your lexical scope, which is unfortunate at best.
1401 # Just exactly what part of the word "CORE::" don't you understand?
1402 local $SIG{__WARN__};
1403 local $SIG{__DIE__};
1405 unless ( is_safe_file($file) ) {
1406 CORE::warn <<EO_GRIPE;
1407 perldb: Must not source insecure rcfile $file.
1408 You or the superuser must be the owner, and it must not
1409 be writable by anyone but its owner.
1412 } ## end unless (is_safe_file($file...
1415 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1416 } ## end sub safe_do
1418 # This is the safety test itself.
1420 # Verifies that owner is either real user or superuser and that no
1421 # one but owner may write to it. This function is of limited use
1422 # when called on a path instead of upon a handle, because there are
1423 # no guarantees that filename (by dirent) whose file (by ino) is
1424 # eventually accessed is the same as the one tested.
1425 # Assumes that the file's existence is not in doubt.
1428 stat($path) || return; # mysteriously vaporized
1429 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1431 return 0 if $uid != 0 && $uid != $<;
1432 return 0 if $mode & 022;
1434 } ## end sub is_safe_file
1436 # If the rcfile (whichever one we decided was the right one to read)
1437 # exists, we safely do it.
1439 safe_do("./$rcfile");
1442 # If there isn't one here, try the user's home directory.
1443 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1444 safe_do("$ENV{HOME}/$rcfile");
1447 # Else try the login directory.
1448 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1449 safe_do("$ENV{LOGDIR}/$rcfile");
1452 # If the PERLDB_OPTS variable has options in it, parse those out next.
1453 if ( defined $ENV{PERLDB_OPTS} ) {
1454 parse_options( $ENV{PERLDB_OPTS} );
1459 The last thing we do during initialization is determine which subroutine is
1460 to be used to obtain a new terminal when a new debugger is started. Right now,
1461 the debugger only handles X Windows, OS/2, and Mac OS X (darwin).
1465 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1466 # Works if you're running an xterm or xterm-like window, or you're on
1467 # OS/2, or on Mac OS X. This may need some expansion.
1469 if (not defined &get_fork_TTY) # only if no routine exists
1471 if (defined $ENV{TERM} # If we know what kind
1472 # of terminal this is,
1473 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1474 and defined $ENV{DISPLAY} # and what display it's on,
1477 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1479 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1480 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1482 elsif ( $^O eq 'darwin' # If this is Mac OS X
1483 and defined $ENV{TERM_PROGRAM} # and we're running inside
1484 and $ENV{TERM_PROGRAM}
1485 eq 'Apple_Terminal' # Terminal.app
1488 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1490 } ## end if (not defined &get_fork_TTY...
1492 # untaint $^O, which may have been tainted by the last statement.
1493 # see bug [perl #24674]
1497 # Here begin the unreadable code. It needs fixing.
1499 =head2 RESTART PROCESSING
1501 This section handles the restart command. When the C<R> command is invoked, it
1502 tries to capture all of the state it can into environment variables, and
1503 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1504 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1505 the R command stuffed into the environment variables.
1507 PERLDB_RESTART - flag only, contains no restart data itself.
1508 PERLDB_HIST - command history, if it's available
1509 PERLDB_ON_LOAD - breakpoints set by the rc file
1510 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1511 PERLDB_VISITED - files that had breakpoints
1512 PERLDB_FILE_... - breakpoints for a file
1513 PERLDB_OPT - active options
1514 PERLDB_INC - the original @INC
1515 PERLDB_PRETYPE - preprompt debugger actions
1516 PERLDB_PRE - preprompt Perl code
1517 PERLDB_POST - post-prompt Perl code
1518 PERLDB_TYPEAHEAD - typeahead captured by readline()
1520 We chug through all these variables and plug the values saved in them
1521 back into the appropriate spots in the debugger.
1525 if ( exists $ENV{PERLDB_RESTART} ) {
1527 # We're restarting, so we don't need the flag that says to restart anymore.
1528 delete $ENV{PERLDB_RESTART};
1531 @hist = get_list('PERLDB_HIST');
1532 %break_on_load = get_list("PERLDB_ON_LOAD");
1533 %postponed = get_list("PERLDB_POSTPONE");
1537 share(%break_on_load);
1540 # restore breakpoints/actions
1541 my @had_breakpoints = get_list("PERLDB_VISITED");
1542 for ( 0 .. $#had_breakpoints ) {
1543 my %pf = get_list("PERLDB_FILE_$_");
1544 $postponed_file{ $had_breakpoints[$_] } = \%pf if %pf;
1548 my %opt = get_list("PERLDB_OPT");
1550 while ( ( $opt, $val ) = each %opt ) {
1551 $val =~ s/[\\\']/\\$1/g;
1552 parse_options("$opt'$val'");
1555 # restore original @INC
1556 @INC = get_list("PERLDB_INC");
1559 # return pre/postprompt actions and typeahead buffer
1560 $pretype = [ get_list("PERLDB_PRETYPE") ];
1561 $pre = [ get_list("PERLDB_PRE") ];
1562 $post = [ get_list("PERLDB_POST") ];
1563 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1564 } ## end if (exists $ENV{PERLDB_RESTART...
1566 =head2 SETTING UP THE TERMINAL
1568 Now, we'll decide how the debugger is going to interact with the user.
1569 If there's no TTY, we set the debugger to run non-stop; there's not going
1570 to be anyone there to enter commands.
1581 If there is a TTY, we have to determine who it belongs to before we can
1582 proceed. If this is a slave editor or graphical debugger (denoted by
1583 the first command-line switch being '-emacs'), we shift this off and
1584 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1590 # Is Perl being run from a slave editor or graphical debugger?
1591 # If so, don't use readline, and set $slave_editor = 1.
1593 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1594 $rl = 0, shift(@main::ARGV) if $slave_editor;
1596 #require Term::ReadLine;
1600 We then determine what the console should be on various systems:
1604 =item * Cygwin - We use C<stdin> instead of a separate device.
1608 if ( $^O eq 'cygwin' ) {
1610 # /dev/tty is binary. use stdin for textmode
1614 =item * Unix - use C</dev/tty>.
1618 elsif ( -e "/dev/tty" ) {
1619 $console = "/dev/tty";
1622 =item * Windows or MSDOS - use C<con>.
1626 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1630 =item * MacOS - use C<Dev:Console:Perl Debug> if this is the MPW version; C<Dev:
1633 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.
1637 elsif ( $^O eq 'MacOS' ) {
1638 if ( $MacPerl::Version !~ /MPW/ ) {
1640 "Dev:Console:Perl Debug"; # Separate window for application
1643 $console = "Dev:Console";
1645 } ## end elsif ($^O eq 'MacOS')
1647 =item * VMS - use C<sys$command>.
1653 # everything else is ...
1654 $console = "sys\$command";
1661 Several other systems don't use a specific console. We C<undef $console>
1662 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1663 with a slave editor, Epoc).
1667 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1669 # /dev/tty is binary. use stdin for textmode
1673 if ( $^O eq 'NetWare' ) {
1675 # /dev/tty is binary. use stdin for textmode
1679 # In OS/2, we need to use STDIN to get textmode too, even though
1680 # it pretty much looks like Unix otherwise.
1681 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1686 # EPOC also falls into the 'got to use STDIN' camp.
1687 if ( $^O eq 'epoc' ) {
1693 If there is a TTY hanging around from a parent, we use that as the console.
1697 $console = $tty if defined $tty;
1699 =head2 SOCKET HANDLING
1701 The debugger is capable of opening a socket and carrying out a debugging
1702 session over the socket.
1704 If C<RemotePort> was defined in the options, the debugger assumes that it
1705 should try to start a debugging session on that port. It builds the socket
1706 and then tries to connect the input and output filehandles to it.
1710 # Handle socket stuff.
1712 if ( defined $remoteport ) {
1714 # If RemotePort was defined in the options, connect input and output
1717 $OUT = new IO::Socket::INET(
1719 PeerAddr => $remoteport,
1722 if ( !$OUT ) { die "Unable to connect to remote host: $remoteport\n"; }
1724 } ## end if (defined $remoteport)
1728 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1729 this is probably a situation where multiple debuggers are running (for example,
1730 a backticked command that starts up another debugger). We create a new IN and
1731 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1739 # Two debuggers running (probably a system or a backtick that invokes
1740 # the debugger itself under the running one). create a new IN and OUT
1741 # filehandle, and do the necessary mojo to create a new tty if we
1742 # know how, and we can.
1743 create_IN_OUT(4) if $CreateTTY & 4;
1746 # If we have a console, check to see if there are separate ins and
1747 # outs to open. (They are assumed identical if not.)
1749 my ( $i, $o ) = split /,/, $console;
1750 $o = $i unless defined $o;
1752 # read/write on in, or just read, or read on STDIN.
1754 || open( IN, "<$i" )
1755 || open( IN, "<&STDIN" );
1757 # read/write/create/clobber out, or write/create/clobber out,
1758 # or merge with STDERR, or merge with STDOUT.
1760 || open( OUT, ">$o" )
1761 || open( OUT, ">&STDERR" )
1762 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1764 } ## end if ($console)
1765 elsif ( not defined $console ) {
1767 # No console. Open STDIN.
1768 open( IN, "<&STDIN" );
1770 # merge with STDERR, or with STDOUT.
1771 open( OUT, ">&STDERR" )
1772 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1773 $console = 'STDIN/OUT';
1774 } ## end elsif (not defined $console)
1776 # Keep copies of the filehandles so that when the pager runs, it
1777 # can close standard input without clobbering ours.
1778 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1779 } ## end elsif (from if(defined $remoteport))
1781 # Unbuffer DB::OUT. We need to see responses right away.
1782 my $previous = select($OUT);
1783 $| = 1; # for DB::OUT
1786 # Line info goes to debugger output unless pointed elsewhere.
1787 # Pointing elsewhere makes it possible for slave editors to
1788 # keep track of file and position. We have both a filehandle
1789 # and a I/O description to keep track of.
1790 $LINEINFO = $OUT unless defined $LINEINFO;
1791 $lineinfo = $console unless defined $lineinfo;
1792 # share($LINEINFO); # <- unable to share globs
1797 To finish initialization, we show the debugger greeting,
1798 and then call the C<afterinit()> subroutine if there is one.
1802 # Show the debugger greeting.
1803 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1804 unless ($runnonstop) {
1807 if ( $term_pid eq '-1' ) {
1808 print $OUT "\nDaughter DB session started...\n";
1811 print $OUT "\nLoading DB routines from $header\n";
1814 $slave_editor ? "enabled" : "available", ".\n"
1817 "\nEnter h or `h h' for help, or `$doccmd perldebug' for more help.\n\n";
1818 } ## end else [ if ($term_pid eq '-1')
1819 } ## end unless ($runnonstop)
1820 } ## end else [ if ($notty)
1822 # XXX This looks like a bug to me.
1823 # Why copy to @ARGS and then futz with @args?
1826 # Make sure backslashes before single quotes are stripped out, and
1827 # keep args unless they are numeric (XXX why?)
1828 # s/\'/\\\'/g; # removed while not justified understandably
1829 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1832 # If there was an afterinit() sub defined, call it. It will get
1833 # executed in our scope, so it can fiddle with debugger globals.
1834 if ( defined &afterinit ) { # May be defined in $rcfile
1838 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1841 ############################################################ Subroutines
1847 This gigantic subroutine is the heart of the debugger. Called before every
1848 statement, its job is to determine if a breakpoint has been reached, and
1849 stop if so; read commands from the user, parse them, and execute
1850 them, and hen send execution off to the next statement.
1852 Note that the order in which the commands are processed is very important;
1853 some commands earlier in the loop will actually alter the C<$cmd> variable
1854 to create other commands to be executed later. This is all highly I<optimized>
1855 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1856 see what's happening in any given command.
1862 # lock the debugger and get the thread id for the prompt
1865 if ($ENV{PERL5DB_THREADED}) {
1866 $tid = eval { "[".threads->tid."]" };
1869 # Check for whether we should be running continuously or not.
1870 # _After_ the perl program is compiled, $single is set to 1:
1871 if ( $single and not $second_time++ ) {
1873 # Options say run non-stop. Run until we get an interrupt.
1874 if ($runnonstop) { # Disable until signal
1875 # If there's any call stack in place, turn off single
1876 # stepping into subs throughout the stack.
1877 for ( $i = 0 ; $i <= $stack_depth ; ) {
1878 $stack[ $i++ ] &= ~1;
1881 # And we are now no longer in single-step mode.
1884 # If we simply returned at this point, we wouldn't get
1885 # the trace info. Fall on through.
1887 } ## end if ($runnonstop)
1889 elsif ($ImmediateStop) {
1891 # We are supposed to stop here; XXX probably a break.
1892 $ImmediateStop = 0; # We've processed it; turn it off
1893 $signal = 1; # Simulate an interrupt to force
1894 # us into the command loop
1896 } ## end if ($single and not $second_time...
1898 # If we're in single-step mode, or an interrupt (real or fake)
1899 # has occurred, turn off non-stop mode.
1900 $runnonstop = 0 if $single or $signal;
1902 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1903 # The code being debugged may have altered them.
1906 # Since DB::DB gets called after every line, we can use caller() to
1907 # figure out where we last were executing. Sneaky, eh? This works because
1908 # caller is returning all the extra information when called from the
1910 local ( $package, $filename, $line ) = caller;
1911 local $filename_ini = $filename;
1913 # set up the context for DB::eval, so it can properly execute
1914 # code on behalf of the user. We add the package in so that the
1915 # code is eval'ed in the proper package (not in the debugger!).
1916 local $usercontext =
1917 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' . "package $package;";
1919 # Create an alias to the active file magical array to simplify
1921 local (*dbline) = $main::{ '_<' . $filename };
1923 # we need to check for pseudofiles on Mac OS (these are files
1924 # not attached to a filename, but instead stored in Dev:Pseudo)
1925 if ( $^O eq 'MacOS' && $#dbline < 0 ) {
1926 $filename_ini = $filename = 'Dev:Pseudo';
1927 *dbline = $main::{ '_<' . $filename };
1930 # Last line in the program.
1931 local $max = $#dbline;
1933 # if we have something here, see if we should break.
1935 && ( ( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1938 # Stop if the stop criterion says to just stop.
1939 if ( $stop eq '1' ) {
1943 # It's a conditional stop; eval it in the user's context and
1944 # see if we should stop. If so, remove the one-time sigil.
1946 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1948 $dbline{$line} =~ s/;9($|\0)/$1/;
1950 } ## end if ($dbline{$line} && ...
1952 # Preserve the current stop-or-not, and see if any of the W
1953 # (watch expressions) has changed.
1954 my $was_signal = $signal;
1956 # If we have any watch expressions ...
1958 for ( my $n = 0 ; $n <= $#to_watch ; $n++ ) {
1959 $evalarg = $to_watch[$n];
1960 local $onetimeDump; # Tell DB::eval() to not output results
1962 # Fix context DB::eval() wants to return an array, but
1963 # we need a scalar here.
1964 my ($val) = join( "', '", &eval );
1965 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
1968 if ( $val ne $old_watch[$n] ) {
1970 # Yep! Show the difference, and fake an interrupt.
1973 Watchpoint $n:\t$to_watch[$n] changed:
1974 old value:\t$old_watch[$n]
1977 $old_watch[$n] = $val;
1978 } ## end if ($val ne $old_watch...
1979 } ## end for (my $n = 0 ; $n <= ...
1980 } ## end if ($trace & 2)
1982 =head2 C<watchfunction()>
1984 C<watchfunction()> is a function that can be defined by the user; it is a
1985 function which will be run on each entry to C<DB::DB>; it gets the
1986 current package, filename, and line as its parameters.
1988 The watchfunction can do anything it likes; it is executing in the
1989 debugger's context, so it has access to all of the debugger's internal
1990 data structures and functions.
1992 C<watchfunction()> can control the debugger's actions. Any of the following
1993 will cause the debugger to return control to the user's program after
1994 C<watchfunction()> executes:
2000 Returning a false value from the C<watchfunction()> itself.
2004 Altering C<$single> to a false value.
2008 Altering C<$signal> to a false value.
2012 Turning off the C<4> bit in C<$trace> (this also disables the
2013 check for C<watchfunction()>. This can be done with
2021 # If there's a user-defined DB::watchfunction, call it with the
2022 # current package, filename, and line. The function executes in
2024 if ( $trace & 4 ) { # User-installed watch
2026 if watchfunction( $package, $filename, $line )
2029 and not( $trace & ~4 );
2030 } ## end if ($trace & 4)
2032 # Pick up any alteration to $signal in the watchfunction, and
2033 # turn off the signal now.
2034 $was_signal = $signal;
2037 =head2 GETTING READY TO EXECUTE COMMANDS
2039 The debugger decides to take control if single-step mode is on, the
2040 C<t> command was entered, or the user generated a signal. If the program
2041 has fallen off the end, we set things up so that entering further commands
2042 won't cause trouble, and we say that the program is over.
2046 # Check to see if we should grab control ($single true,
2047 # trace set appropriately, or we got a signal).
2048 if ( $single || ( $trace & 1 ) || $was_signal ) {
2050 # Yes, grab control.
2051 if ($slave_editor) {
2053 # Tell the editor to update its position.
2054 $position = "\032\032$filename:$line:0\n";
2055 print_lineinfo($position);
2060 Special check: if we're in package C<DB::fake>, we've gone through the
2061 C<END> block at least once. We set up everything so that we can continue
2062 to enter commands and have a valid context to be in.
2066 elsif ( $package eq 'DB::fake' ) {
2068 # Fallen off the end already.
2071 Debugged program terminated. Use B<q> to quit or B<R> to restart,
2072 use B<o> I<inhibit_exit> to avoid stopping after program termination,
2073 B<h q>, B<h R> or B<h o> to get additional info.
2076 # Set the DB::eval context appropriately.
2079 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;'
2080 . "package $package;"; # this won't let them modify, alas
2081 } ## end elsif ($package eq 'DB::fake')
2085 If the program hasn't finished executing, we scan forward to the
2086 next executable line, print that out, build the prompt from the file and line
2087 number information, and print that.
2093 # Still somewhere in the midst of execution. Set up the
2095 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
2096 # Perl 5 ones (sorry, we don't print Klingon
2099 $prefix = $sub =~ /::/ ? "" : "${'package'}::";
2100 $prefix .= "$sub($filename:";
2101 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" );
2103 # Break up the prompt if it's really long.
2104 if ( length($prefix) > 30 ) {
2105 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
2111 $position = "$prefix$line$infix$dbline[$line]$after";
2114 # Print current line info, indenting if necessary.
2116 print_lineinfo( ' ' x $stack_depth,
2117 "$line:\t$dbline[$line]$after" );
2120 print_lineinfo($position);
2123 # Scan forward, stopping at either the end or the next
2125 for ( $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i )
2128 # Drop out on null statements, block closers, and comments.
2129 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
2131 # Drop out if the user interrupted us.
2134 # Append a newline if the line doesn't have one. Can happen
2135 # in eval'ed text, for instance.
2136 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" );
2138 # Next executable line.
2139 $incr_pos = "$prefix$i$infix$dbline[$i]$after";
2140 $position .= $incr_pos;
2143 # Print it indented if tracing is on.
2144 print_lineinfo( ' ' x $stack_depth,
2145 "$i:\t$dbline[$i]$after" );
2148 print_lineinfo($incr_pos);
2150 } ## end for ($i = $line + 1 ; $i...
2151 } ## end else [ if ($slave_editor)
2152 } ## end if ($single || ($trace...
2156 If there's an action to be executed for the line we stopped at, execute it.
2157 If there are any preprompt actions, execute those as well.
2161 # If there's an action, do it now.
2162 $evalarg = $action, &eval if $action;
2164 # Are we nested another level (e.g., did we evaluate a function
2165 # that had a breakpoint in it at the debugger prompt)?
2166 if ( $single || $was_signal ) {
2168 # Yes, go down a level.
2169 local $level = $level + 1;
2171 # Do any pre-prompt actions.
2172 foreach $evalarg (@$pre) {
2176 # Complain about too much recursion if we passed the limit.
2177 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
2180 # The line we're currently on. Set $incr to -1 to stay here
2181 # until we get a command that tells us to advance.
2183 $incr = -1; # for backward motion.
2185 # Tack preprompt debugger actions ahead of any actual input.
2186 @typeahead = ( @$pretype, @typeahead );
2188 =head2 WHERE ARE WE?
2190 XXX Relocate this section?
2192 The debugger normally shows the line corresponding to the current line of
2193 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2194 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2196 C<$incr> controls by how many lines the I<current> line should move forward
2197 after a command is executed. If set to -1, this indicates that the I<current>
2198 line shouldn't change.
2200 C<$start> is the I<current> line. It is used for things like knowing where to
2201 move forwards or backwards from when doing an C<L> or C<-> command.
2203 C<$max> tells the debugger where the last line of the current file is. It's
2204 used to terminate loops most often.
2206 =head2 THE COMMAND LOOP
2208 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2215 The outer part of the loop, starting at the C<CMD> label. This loop
2216 reads a command and then executes it.
2220 The inner part of the loop, starting at the C<PIPE> label. This part
2221 is wholly contained inside the C<CMD> block and only executes a command.
2222 Used to handle commands running inside a pager.
2226 So why have two labels to restart the loop? Because sometimes, it's easier to
2227 have a command I<generate> another command and then re-execute the loop to do
2228 the new command. This is faster, but perhaps a bit more convoluted.
2232 # The big command dispatch loop. It keeps running until the
2233 # user yields up control again.
2235 # If we have a terminal for input, and we get something back
2236 # from readline(), keep on processing.
2240 # We have a terminal, or can get one ...
2241 ( $term || &setterm ),
2243 # ... and it belogs to this PID or we get one for this PID ...
2244 ( $term_pid == $$ or resetterm(1) ),
2246 # ... and we got a line of command input ...
2249 "$pidprompt $tid DB"
2252 . ( '>' x $level ) . " "
2259 # ... try to execute the input as debugger commands.
2261 # Don't stop running.
2264 # No signal is active.
2267 # Handle continued commands (ending with \):
2268 $cmd =~ s/\\$/\n/ && do {
2269 $cmd .= &readline(" cont: ");
2273 =head4 The null command
2275 A newline entered by itself means I<re-execute the last command>. We grab the
2276 command out of C<$laststep> (where it was recorded previously), and copy it
2277 back into C<$cmd> to be executed below. If there wasn't any previous command,
2278 we'll do nothing below (no command will match). If there was, we also save it
2279 in the command history and fall through to allow the command parsing to pick
2284 # Empty input means repeat the last command.
2285 $cmd =~ /^$/ && ( $cmd = $laststep );
2286 chomp($cmd); # get rid of the annoying extra newline
2287 push( @hist, $cmd ) if length($cmd) > 1;
2288 push( @truehist, $cmd );
2292 # This is a restart point for commands that didn't arrive
2293 # via direct user input. It allows us to 'redo PIPE' to
2294 # re-execute command processing without reading a new command.
2296 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2297 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
2298 ($i) = split( /\s+/, $cmd );
2300 =head3 COMMAND ALIASES
2302 The debugger can create aliases for commands (these are stored in the
2303 C<%alias> hash). Before a command is executed, the command loop looks it up
2304 in the alias hash and substitutes the contents of the alias for the command,
2305 completely replacing it.
2309 # See if there's an alias for the command, and set it up if so.
2312 # Squelch signal handling; we want to keep control here
2313 # if something goes loco during the alias eval.
2314 local $SIG{__DIE__};
2315 local $SIG{__WARN__};
2317 # This is a command, so we eval it in the DEBUGGER's
2318 # scope! Otherwise, we can't see the special debugger
2319 # variables, or get to the debugger's subs. (Well, we
2320 # _could_, but why make it even more complicated?)
2321 eval "\$cmd =~ $alias{$i}";
2324 print $OUT "Couldn't evaluate `$i' alias: $@";
2327 } ## end if ($alias{$i})
2329 =head3 MAIN-LINE COMMANDS
2331 All of these commands work up to and after the program being debugged has
2336 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2337 try to execute further, cleaning any restart-related stuff out of the
2338 environment, and executing with the last value of C<$?>.
2342 $cmd =~ /^q$/ && do {
2350 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2354 $cmd =~ /^t$/ && do {
2357 print $OUT "Trace = "
2358 . ( ( $trace & 1 ) ? "on" : "off" ) . "\n";
2362 =head4 C<S> - list subroutines matching/not matching a pattern
2364 Walks through C<%sub>, checking to see whether or not to print the name.
2368 $cmd =~ /^S(\s+(!)?(.+))?$/ && do {
2370 $Srev = defined $2; # Reverse scan?
2371 $Spatt = $3; # The pattern (if any) to use.
2372 $Snocheck = !defined $1; # No args - print all subs.
2374 # Need to make these sane here.
2378 # Search through the debugger's magical hash of subs.
2379 # If $nocheck is true, just print the sub name.
2380 # Otherwise, check it against the pattern. We then use
2381 # the XOR trick to reverse the condition as required.
2382 foreach $subname ( sort( keys %sub ) ) {
2383 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2384 print $OUT $subname, "\n";
2390 =head4 C<X> - list variables in current package
2392 Since the C<V> command actually processes this, just change this to the
2393 appropriate C<V> command and fall through.
2397 $cmd =~ s/^X\b/V $package/;
2399 =head4 C<V> - list variables
2401 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2405 # Bare V commands get the currently-being-debugged package
2407 $cmd =~ /^V$/ && do {
2408 $cmd = "V $package";
2411 # V - show variables in package.
2412 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
2414 # Save the currently selected filehandle and
2415 # force output to debugger's filehandle (dumpvar
2416 # just does "print" for output).
2417 local ($savout) = select($OUT);
2419 # Grab package name and variables to dump.
2421 @vars = split( ' ', $2 );
2423 # If main::dumpvar isn't here, get it.
2424 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
2425 if ( defined &main::dumpvar ) {
2427 # We got it. Turn off subroutine entry/exit messages
2428 # for the moment, along with return values.
2432 # must detect sigpipe failures - not catching
2433 # then will cause the debugger to die.
2437 defined $option{dumpDepth}
2438 ? $option{dumpDepth}
2439 : -1, # assume -1 unless specified
2444 # The die doesn't need to include the $@, because
2445 # it will automatically get propagated for us.
2447 die unless $@ =~ /dumpvar print failed/;
2449 } ## end if (defined &main::dumpvar)
2452 # Couldn't load dumpvar.
2453 print $OUT "dumpvar.pl not available.\n";
2456 # Restore the output filehandle, and go round again.
2461 =head4 C<x> - evaluate and print an expression
2463 Hands the expression off to C<DB::eval>, setting it up to print the value
2464 via C<dumpvar.pl> instead of just printing it directly.
2468 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval()
2469 $onetimeDump = 'dump'; # main::dumpvar shows the output
2471 # handle special "x 3 blah" syntax XXX propagate
2472 # doc back to special variables.
2473 if ( $cmd =~ s/^\s*(\d+)(?=\s)/ / ) {
2474 $onetimedumpDepth = $1;
2478 =head4 C<m> - print methods
2480 Just uses C<DB::methods> to determine what methods are available.
2484 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do {
2489 # m expr - set up DB::eval to do the work
2490 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval()
2491 $onetimeDump = 'methods'; # method output gets used there
2494 =head4 C<f> - switch files
2498 $cmd =~ /^f\b\s*(.*)/ && do {
2502 # help for no arguments (old-style was return from sub).
2505 "The old f command is now the r command.\n"; # hint
2506 print $OUT "The new f command switches filenames.\n";
2508 } ## end if (!$file)
2510 # if not in magic file list, try a close match.
2511 if ( !defined $main::{ '_<' . $file } ) {
2512 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2514 $try = substr( $try, 2 );
2515 print $OUT "Choosing $try matching `$file':\n";
2518 } ## end if (($try) = grep(m#^_<.*$file#...
2519 } ## end if (!defined $main::{ ...
2521 # If not successfully switched now, we failed.
2522 if ( !defined $main::{ '_<' . $file } ) {
2523 print $OUT "No file matching `$file' is loaded.\n";
2527 # We switched, so switch the debugger internals around.
2528 elsif ( $file ne $filename ) {
2529 *dbline = $main::{ '_<' . $file };
2534 } ## end elsif ($file ne $filename)
2536 # We didn't switch; say we didn't.
2538 print $OUT "Already in $file.\n";
2543 =head4 C<.> - return to last-executed line.
2545 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2546 and then we look up the line in the magical C<%dbline> hash.
2551 $cmd =~ /^\.$/ && do {
2552 $incr = -1; # stay at current line
2554 # Reset everything to the old location.
2556 $filename = $filename_ini;
2557 *dbline = $main::{ '_<' . $filename };
2561 print_lineinfo($position);
2565 =head4 C<-> - back one window
2567 We change C<$start> to be one window back; if we go back past the first line,
2568 we set it to be the first line. We ser C<$incr> to put us back at the
2569 currently-executing line, and then put a C<l $start +> (list one window from
2570 C<$start>) in C<$cmd> to be executed later.
2574 # - - back a window.
2575 $cmd =~ /^-$/ && do {
2577 # back up by a window; go to 1 if back too far.
2578 $start -= $incr + $window + 1;
2579 $start = 1 if $start <= 0;
2580 $incr = $window - 1;
2582 # Generate and execute a "l +" command (handled below).
2583 $cmd = 'l ' . ($start) . '+';
2586 =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>, {, {{>
2588 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2589 problems, most notably that the default case of several commands destroying
2590 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2591 retain the old commands for those who were used to using them or who preferred
2592 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2593 deal with them instead of processing them in-line.
2597 # All of these commands were remapped in perl 5.8.0;
2598 # we send them off to the secondary dispatcher (see below).
2599 $cmd =~ /^([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do {
2600 &cmd_wrapper( $1, $2, $line );
2604 =head4 C<y> - List lexicals in higher scope
2606 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2607 above the current one and then displays then using C<dumpvar.pl>.
2611 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do {
2613 # See if we've got the necessary support.
2614 eval { require PadWalker; PadWalker->VERSION(0.08) }
2617 ? "PadWalker module not found - please install\n"
2622 # Load up dumpvar if we don't have it. If we can, that is.
2623 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
2624 defined &main::dumpvar
2625 or print $OUT "dumpvar.pl not available.\n"
2628 # Got all the modules we need. Find them and print them.
2629 my @vars = split( ' ', $2 || '' );
2632 my $h = eval { PadWalker::peek_my( ( $1 || 0 ) + 1 ) };
2634 # Oops. Can't find it.
2635 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2637 # Show the desired vars with dumplex().
2638 my $savout = select($OUT);
2640 # Have dumplex dump the lexicals.
2641 dumpvar::dumplex( $_, $h->{$_},
2642 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
2649 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2651 All of the commands below this point don't work after the program being
2652 debugged has ended. All of them check to see if the program has ended; this
2653 allows the commands to be relocated without worrying about a 'line of
2654 demarcation' above which commands can be entered anytime, and below which
2657 =head4 C<n> - single step, but don't trace down into subs
2659 Done by setting C<$single> to 2, which forces subs to execute straight through
2660 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2661 so a null command knows what to re-execute.
2666 $cmd =~ /^n$/ && do {
2667 end_report(), next CMD if $finished and $level <= 1;
2669 # Single step, but don't enter subs.
2672 # Save for empty command (repeat last).
2677 =head4 C<s> - single-step, entering subs
2679 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2680 subs. Also saves C<s> as C<$lastcmd>.
2685 $cmd =~ /^s$/ && do {
2687 # Get out and restart the command loop if program
2689 end_report(), next CMD if $finished and $level <= 1;
2691 # Single step should enter subs.
2694 # Save for empty command (repeat last).
2699 =head4 C<c> - run continuously, setting an optional breakpoint
2701 Most of the code for this command is taken up with locating the optional
2702 breakpoint, which is either a subroutine name or a line number. We set
2703 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2704 in this and all call levels above this one.
2708 # c - start continuous execution.
2709 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do {
2711 # Hey, show's over. The debugged program finished
2712 # executing already.
2713 end_report(), next CMD if $finished and $level <= 1;
2715 # Capture the place to put a one-time break.
2718 # Probably not needed, since we finish an interactive
2719 # sub-session anyway...
2720 # local $filename = $filename;
2721 # local *dbline = *dbline; # XXX Would this work?!
2723 # The above question wonders if localizing the alias
2724 # to the magic array works or not. Since it's commented
2725 # out, we'll just leave that to speculation for now.
2727 # If the "subname" isn't all digits, we'll assume it
2728 # is a subroutine name, and try to find it.
2729 if ( $subname =~ /\D/ ) { # subroutine name
2730 # Qualify it to the current package unless it's
2731 # already qualified.
2732 $subname = $package . "::" . $subname
2733 unless $subname =~ /::/;
2735 # find_sub will return "file:line_number" corresponding
2736 # to where the subroutine is defined; we call find_sub,
2737 # break up the return value, and assign it in one
2739 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2741 # Force the line number to be numeric.
2744 # If we got a line number, we found the sub.
2747 # Switch all the debugger's internals around so
2748 # we're actually working with that file.
2750 *dbline = $main::{ '_<' . $filename };
2752 # Mark that there's a breakpoint in this file.
2753 $had_breakpoints{$filename} |= 1;
2755 # Scan forward to the first executable line
2756 # after the 'sub whatever' line.
2758 ++$i while $dbline[$i] == 0 && $i < $max;
2761 # We didn't find a sub by that name.
2763 print $OUT "Subroutine $subname not found.\n";
2766 } ## end if ($subname =~ /\D/)
2768 # At this point, either the subname was all digits (an
2769 # absolute line-break request) or we've scanned through
2770 # the code following the definition of the sub, looking
2771 # for an executable, which we may or may not have found.
2773 # If $i (which we set $subname from) is non-zero, we
2774 # got a request to break at some line somewhere. On
2775 # one hand, if there wasn't any real subroutine name
2776 # involved, this will be a request to break in the current
2777 # file at the specified line, so we have to check to make
2778 # sure that the line specified really is breakable.
2780 # On the other hand, if there was a subname supplied, the
2781 # preceding block has moved us to the proper file and
2782 # location within that file, and then scanned forward
2783 # looking for the next executable line. We have to make
2784 # sure that one was found.
2786 # On the gripping hand, we can't do anything unless the
2787 # current value of $i points to a valid breakable line.
2792 if ( $dbline[$i] == 0 ) {
2793 print $OUT "Line $i not breakable.\n";
2797 # Yes. Set up the one-time-break sigil.
2798 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2801 # Turn off stack tracing from here up.
2802 for ( $i = 0 ; $i <= $stack_depth ; ) {
2803 $stack[ $i++ ] &= ~1;
2808 =head4 C<r> - return from a subroutine
2810 For C<r> to work properly, the debugger has to stop execution again
2811 immediately after the return is executed. This is done by forcing
2812 single-stepping to be on in the call level above the current one. If
2813 we are printing return values when a C<r> is executed, set C<$doret>
2814 appropriately, and force us out of the command loop.
2818 # r - return from the current subroutine.
2819 $cmd =~ /^r$/ && do {
2821 # Can't do anythign if the program's over.
2822 end_report(), next CMD if $finished and $level <= 1;
2824 # Turn on stack trace.
2825 $stack[$stack_depth] |= 1;
2827 # Print return value unless the stack is empty.
2828 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2832 =head4 C<T> - stack trace
2834 Just calls C<DB::print_trace>.
2838 $cmd =~ /^T$/ && do {
2839 print_trace( $OUT, 1 ); # skip DB
2843 =head4 C<w> - List window around current line.
2845 Just calls C<DB::cmd_w>.
2849 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w( 'w', $1 ); next CMD; };
2851 =head4 C<W> - watch-expression processing.
2853 Just calls C<DB::cmd_W>.
2857 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W( 'W', $1 ); next CMD; };
2859 =head4 C</> - search forward for a string in the source
2861 We take the argument and treat it as a pattern. If it turns out to be a
2862 bad one, we return the error we got from trying to C<eval> it and exit.
2863 If not, we create some code to do the search and C<eval> it so it can't
2868 $cmd =~ /^\/(.*)$/ && do {
2870 # The pattern as a string.
2873 # Remove the final slash.
2874 $inpat =~ s:([^\\])/$:$1:;
2876 # If the pattern isn't null ...
2877 if ( $inpat ne "" ) {
2879 # Turn of warn and die procesing for a bit.
2880 local $SIG{__DIE__};
2881 local $SIG{__WARN__};
2883 # Create the pattern.
2884 eval '$inpat =~ m' . "\a$inpat\a";
2887 # Oops. Bad pattern. No biscuit.
2888 # Print the eval error and go back for more
2894 } ## end if ($inpat ne "")
2896 # Set up to stop on wrap-around.
2899 # Don't move off the current line.
2902 # Done in eval so nothing breaks if the pattern
2903 # does something weird.
2906 # Move ahead one line.
2909 # Wrap if we pass the last line.
2910 $start = 1 if ($start > $max);
2912 # Stop if we have gotten back to this line again,
2913 last if ($start == $end);
2915 # A hit! (Note, though, that we are doing
2916 # case-insensitive matching. Maybe a qr//
2917 # expression would be better, so the user could
2918 # do case-sensitive matching if desired.
2919 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2920 if ($slave_editor) {
2921 # Handle proper escaping in the slave.
2922 print $OUT "\032\032$filename:$start:0\n";
2925 # Just print the line normally.
2926 print $OUT "$start:\t",$dbline[$start],"\n";
2928 # And quit since we found something.
2933 # If we wrapped, there never was a match.
2934 print $OUT "/$pat/: not found\n" if ( $start == $end );
2938 =head4 C<?> - search backward for a string in the source
2940 Same as for C</>, except the loop runs backwards.
2944 # ? - backward pattern search.
2945 $cmd =~ /^\?(.*)$/ && do {
2947 # Get the pattern, remove trailing question mark.
2949 $inpat =~ s:([^\\])\?$:$1:;
2951 # If we've got one ...
2952 if ( $inpat ne "" ) {
2954 # Turn off die & warn handlers.
2955 local $SIG{__DIE__};
2956 local $SIG{__WARN__};
2957 eval '$inpat =~ m' . "\a$inpat\a";
2961 # Ouch. Not good. Print the error.
2966 } ## end if ($inpat ne "")
2968 # Where we are now is where to stop after wraparound.
2971 # Don't move away from this line.
2974 # Search inside the eval to prevent pattern badness
2981 # Wrap if we pass the first line.
2983 $start = $max if ($start <= 0);
2985 # Quit if we get back where we started,
2986 last if ($start == $end);
2989 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2990 if ($slave_editor) {
2991 # Yep, follow slave editor requirements.
2992 print $OUT "\032\032$filename:$start:0\n";
2995 # Yep, just print normally.
2996 print $OUT "$start:\t",$dbline[$start],"\n";
3004 # Say we failed if the loop never found anything,
3005 print $OUT "?$pat?: not found\n" if ( $start == $end );
3009 =head4 C<$rc> - Recall command
3011 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
3012 that the terminal supports history). It find the the command required, puts it
3013 into C<$cmd>, and redoes the loop to execute it.
3017 # $rc - recall command.
3018 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do {
3020 # No arguments, take one thing off history.
3021 pop(@hist) if length($cmd) > 1;
3023 # Relative (- found)?
3024 # Y - index back from most recent (by 1 if bare minus)
3025 # N - go to that particular command slot or the last
3026 # thing if nothing following.
3027 $i = $1 ? ( $#hist - ( $2 || 1 ) ) : ( $2 || $#hist );
3029 # Pick out the command desired.
3032 # Print the command to be executed and restart the loop
3033 # with that command in the buffer.
3034 print $OUT $cmd, "\n";
3038 =head4 C<$sh$sh> - C<system()> command
3040 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
3041 C<STDOUT> from getting messed up.
3045 # $sh$sh - run a shell command (if it's all ASCII).
3046 # Can't run shell commands with Unicode in the debugger, hmm.
3047 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do {
3054 =head4 C<$rc I<pattern> $rc> - Search command history
3056 Another command to manipulate C<@hist>: this one searches it with a pattern.
3057 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
3061 # $rc pattern $rc - find a command in the history.
3062 $cmd =~ /^$rc([^$rc].*)$/ && do {
3064 # Create the pattern to use.
3067 # Toss off last entry if length is >1 (and it always is).
3068 pop(@hist) if length($cmd) > 1;
3070 # Look backward through the history.
3071 for ( $i = $#hist ; $i ; --$i ) {
3073 # Stop if we find it.
3074 last if $hist[$i] =~ /$pat/;
3080 print $OUT "No such command!\n\n";
3084 # Found it. Put it in the buffer, print it, and process it.
3086 print $OUT $cmd, "\n";
3090 =head4 C<$sh> - Invoke a shell
3092 Uses C<DB::system> to invoke a shell.
3096 # $sh - start a shell.
3097 $cmd =~ /^$sh$/ && do {
3099 # Run the user's shell. If none defined, run Bourne.
3100 # We resume execution when the shell terminates.
3101 &system( $ENV{SHELL} || "/bin/sh" );
3105 =head4 C<$sh I<command>> - Force execution of a command in a shell
3107 Like the above, but the command is passed to the shell. Again, we use
3108 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3112 # $sh command - start a shell and run a command in it.
3113 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do {
3115 # XXX: using csh or tcsh destroys sigint retvals!
3116 #&system($1); # use this instead
3118 # use the user's shell, or Bourne if none defined.
3119 &system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3123 =head4 C<H> - display commands in history
3125 Prints the contents of C<@hist> (if any).
3129 $cmd =~ /^H\b\s*\*/ && do {
3130 @hist = @truehist = ();
3131 print $OUT "History cleansed\n";
3135 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
3137 # Anything other than negative numbers is ignored by
3138 # the (incorrect) pattern, so this test does nothing.
3139 $end = $2 ? ( $#hist - $2 ) : 0;
3141 # Set to the minimum if less than zero.
3142 $hist = 0 if $hist < 0;
3144 # Start at the end of the array.
3145 # Stay in while we're still above the ending value.
3146 # Tick back by one each time around the loop.
3147 for ( $i = $#hist ; $i > $end ; $i-- ) {
3149 # Print the command unless it has no arguments.
3150 print $OUT "$i: ", $hist[$i], "\n"
3151 unless $hist[$i] =~ /^.?$/;
3156 =head4 C<man, doc, perldoc> - look up documentation
3158 Just calls C<runman()> to print the appropriate document.
3162 # man, perldoc, doc - show manual pages.
3163 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do {
3170 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3171 the bottom of the loop.
3175 # p - print (no args): print $_.
3176 $cmd =~ s/^p$/print {\$DB::OUT} \$_/;
3178 # p - print the given expression.
3179 $cmd =~ s/^p\b/print {\$DB::OUT} /;
3181 =head4 C<=> - define command alias
3183 Manipulates C<%alias> to add or list command aliases.
3187 # = - set up a command alias.
3188 $cmd =~ s/^=\s*// && do {
3190 if ( length $cmd == 0 ) {
3192 # No args, get current aliases.
3193 @keys = sort keys %alias;
3195 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3197 # Creating a new alias. $k is alias name, $v is
3200 # can't use $_ or kill //g state
3201 for my $x ( $k, $v ) {
3203 # Escape "alarm" characters.
3207 # Substitute key for value, using alarm chars
3208 # as separators (which is why we escaped them in
3210 $alias{$k} = "s\a$k\a$v\a";
3212 # Turn off standard warn and die behavior.
3213 local $SIG{__DIE__};
3214 local $SIG{__WARN__};
3217 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3219 # Nope. Bad alias. Say so and get out.
3220 print $OUT "Can't alias $k to $v: $@\n";
3225 # We'll only list the new one.
3227 } ## end elsif (my ($k, $v) = ($cmd...
3229 # The argument is the alias to list.
3237 # Messy metaquoting: Trim the substiution code off.
3238 # We use control-G as the delimiter because it's not
3239 # likely to appear in the alias.
3240 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3243 print $OUT "$k\t= $1\n";
3245 elsif ( defined $alias{$k} ) {
3247 # Couldn't trim it off; just print the alias code.
3248 print $OUT "$k\t$alias{$k}\n";
3253 print "No alias for $k\n";
3255 } ## end for my $k (@keys)
3259 =head4 C<source> - read commands from a file.
3261 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3266 # source - read commands from a file (or pipe!) and execute.
3267 $cmd =~ /^source\s+(.*\S)/ && do {
3268 if ( open my $fh, $1 ) {
3270 # Opened OK; stick it in the list of file handles.
3276 &warn("Can't execute `$1': $!\n");
3281 =head4 C<save> - send current history to a file
3283 Takes the complete history, (not the shrunken version you see with C<H>),
3284 and saves it to the given filename, so it can be replayed using C<source>.
3286 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3290 # save source - write commands to a file for later use
3291 $cmd =~ /^save\s*(.*)$/ && do {
3292 my $file = $1 || '.perl5dbrc'; # default?
3293 if ( open my $fh, "> $file" ) {
3295 # chomp to remove extraneous newlines from source'd files
3296 chomp( my @truelist =
3297 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3299 print $fh join( "\n", @truelist );
3300 print "commands saved in $file\n";
3303 &warn("Can't save debugger commands in '$1': $!\n");
3308 =head4 C<R> - restart
3310 Restart the debugger session.
3312 =head4 C<rerun> - rerun the current session
3314 Return to any given position in the B<true>-history list
3318 # R - restart execution.
3319 # rerun - controlled restart execution.
3320 $cmd =~ /^(R|rerun\s*(.*))$/ && do {
3321 my @args = ($1 eq 'R' ? restart() : rerun($2));
3323 # Close all non-system fds for a clean restart. A more
3324 # correct method would be to close all fds that were not
3325 # open when the process started, but this seems to be
3326 # hard. See "debugger 'R'estart and open database
3327 # connections" on p5p.
3329 my $max_fd = 1024; # default if POSIX can't be loaded
3330 if (eval { require POSIX }) {
3331 $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX());
3334 if (defined $max_fd) {
3335 foreach ($^F+1 .. $max_fd-1) {
3336 next unless open FD_TO_CLOSE, "<&=$_";
3341 # And run Perl again. We use exec() to keep the
3342 # PID stable (and that way $ini_pids is still valid).
3343 exec(@args) || print $OUT "exec failed: $!\n";
3348 =head4 C<|, ||> - pipe output through the pager.
3350 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3351 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3352 pipe to the pager (restoring the output filehandles if this fails). If this
3353 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3354 set C<$signal>, sending us back into the debugger.
3356 We then trim off the pipe symbols and C<redo> the command loop at the
3357 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3362 # || - run command in the pager, with output to DB::OUT.
3363 $cmd =~ /^\|\|?\s*[^|]/ && do {
3364 if ( $pager =~ /^\|/ ) {
3366 # Default pager is into a pipe. Redirect I/O.
3367 open( SAVEOUT, ">&STDOUT" )
3368 || &warn("Can't save STDOUT");
3369 open( STDOUT, ">&OUT" )
3370 || &warn("Can't redirect STDOUT");
3371 } ## end if ($pager =~ /^\|/)
3374 # Not into a pipe. STDOUT is safe.
3375 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3378 # Fix up environment to record we have less if so.
3381 unless ( $piped = open( OUT, $pager ) ) {
3383 # Couldn't open pipe to pager.
3384 &warn("Can't pipe output to `$pager'");
3385 if ( $pager =~ /^\|/ ) {
3387 # Redirect I/O back again.
3388 open( OUT, ">&STDOUT" ) # XXX: lost message
3389 || &warn("Can't restore DB::OUT");
3390 open( STDOUT, ">&SAVEOUT" )
3391 || &warn("Can't restore STDOUT");
3393 } ## end if ($pager =~ /^\|/)
3396 # Redirect I/O. STDOUT already safe.
3397 open( OUT, ">&STDOUT" ) # XXX: lost message
3398 || &warn("Can't restore DB::OUT");
3401 } ## end unless ($piped = open(OUT,...
3403 # Set up broken-pipe handler if necessary.
3404 $SIG{PIPE} = \&DB::catch
3406 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
3408 # Save current filehandle, unbuffer out, and put it back.
3409 $selected = select(OUT);
3412 # Don't put it back if pager was a pipe.
3413 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
3415 # Trim off the pipe symbols and run the command now.
3416 $cmd =~ s/^\|+\s*//;
3420 =head3 END OF COMMAND PARSING
3422 Anything left in C<$cmd> at this point is a Perl expression that we want to
3423 evaluate. We'll always evaluate in the user's context, and fully qualify
3424 any variables we might want to address in the C<DB> package.
3428 # t - turn trace on.
3429 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3431 # s - single-step. Remember the last command was 's'.
3432 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' };
3434 # n - single-step, but not into subs. Remember last command
3436 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' };
3440 # Make sure the flag that says "the debugger's running" is
3441 # still on, to make sure we get control again.
3442 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3444 # Run *our* eval that executes in the caller's context.
3447 # Turn off the one-time-dump stuff now.
3449 $onetimeDump = undef;
3450 $onetimedumpDepth = undef;
3452 elsif ( $term_pid == $$ ) {
3453 eval { # May run under miniperl, when not available...
3458 # XXX If this is the master pid, print a newline.
3461 } ## end while (($term || &setterm...
3463 =head3 POST-COMMAND PROCESSING
3465 After each command, we check to see if the command output was piped anywhere.
3466 If so, we go through the necessary code to unhook the pipe and go back to
3467 our standard filehandles for input and output.
3473 # At the end of every command:
3476 # Unhook the pipe mechanism now.
3477 if ( $pager =~ /^\|/ ) {
3479 # No error from the child.
3482 # we cannot warn here: the handle is missing --tchrist
3483 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
3485 # most of the $? crud was coping with broken cshisms
3486 # $? is explicitly set to 0, so this never runs.
3488 print SAVEOUT "Pager `$pager' failed: ";
3490 print SAVEOUT "shell returned -1\n";
3493 print SAVEOUT ( $? & 127 )
3494 ? " (SIG#" . ( $? & 127 ) . ")"
3495 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3498 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3502 # Reopen filehandle for our output (if we can) and
3503 # restore STDOUT (if we can).
3504 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3505 open( STDOUT, ">&SAVEOUT" )
3506 || &warn("Can't restore STDOUT");
3508 # Turn off pipe exception handler if necessary.
3509 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
3511 # Will stop ignoring SIGPIPE if done like nohup(1)
3512 # does SIGINT but Perl doesn't give us a choice.
3513 } ## end if ($pager =~ /^\|/)
3516 # Non-piped "pager". Just restore STDOUT.
3517 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3520 # Close filehandle pager was using, restore the normal one
3523 select($selected), $selected = "" unless $selected eq "";
3527 } ## end if ($piped)
3530 =head3 COMMAND LOOP TERMINATION
3532 When commands have finished executing, we come here. If the user closed the
3533 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3534 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3535 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3536 The interpreter will then execute the next line and then return control to us
3541 # No more commands? Quit.
3542 $fall_off_end = 1 unless defined $cmd; # Emulate `q' on EOF
3544 # Evaluate post-prompt commands.
3545 foreach $evalarg (@$post) {
3548 } # if ($single || $signal)
3550 # Put the user's globals back where you found them.
3551 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3555 # The following code may be executed now:
3560 C<sub> is called whenever a subroutine call happens in the program being
3561 debugged. The variable C<$DB::sub> contains the name of the subroutine
3564 The core function of this subroutine is to actually call the sub in the proper
3565 context, capturing its output. This of course causes C<DB::DB> to get called
3566 again, repeating until the subroutine ends and returns control to C<DB::sub>
3567 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3568 return value, and returns its captured copy of the return value as its own
3569 return value. The value then feeds back into the program being debugged as if
3570 C<DB::sub> hadn't been there at all.
3572 C<sub> does all the work of printing the subroutine entry and exit messages
3573 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3574 and also prints the return value if needed (for the C<r> command and if
3575 the 16 bit is set in C<$frame>).
3577 It also tracks the subroutine call depth by saving the current setting of
3578 C<$single> in the C<@stack> package global; if this exceeds the value in
3579 C<$deep>, C<sub> automatically turns on printing of the current depth by
3580 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
3581 of stop/don't stop on entry to subs set as it currently is set.
3583 =head3 C<caller()> support
3585 If C<caller()> is called from the package C<DB>, it provides some
3586 additional data, in the following order:
3592 The package name the sub was in
3594 =item * C<$filename>
3596 The filename it was defined in
3600 The line number it was defined on
3602 =item * C<$subroutine>
3604 The subroutine name; C<(eval)> if an C<eval>().
3608 1 if it has arguments, 0 if not
3610 =item * C<$wantarray>
3612 1 if array context, 0 if scalar context
3614 =item * C<$evaltext>
3616 The C<eval>() text, if any (undefined for C<eval BLOCK>)
3618 =item * C<$is_require>
3620 frame was created by a C<use> or C<require> statement
3624 pragma information; subject to change between versions
3628 pragma information; subject to change between versions
3630 =item * C<@DB::args>
3632 arguments with which the subroutine was invoked
3640 # lock ourselves under threads
3643 # Whether or not the autoloader was running, a scalar to put the
3644 # sub's return value in (if needed), and an array to put the sub's
3645 # return value in (if needed).
3646 my ( $al, $ret, @ret ) = "";
3647 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3648 print "creating new thread\n";
3651 # If the last ten characters are C'::AUTOLOAD', note we've traced
3652 # into AUTOLOAD for $sub.
3653 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3657 # We stack the stack pointer and then increment it to protect us
3658 # from a situation that might unwind a whole bunch of call frames
3659 # at once. Localizing the stack pointer means that it will automatically
3660 # unwind the same amount when multiple stack frames are unwound.
3661 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3664 $#stack = $stack_depth;
3666 # Save current single-step setting.
3667 $stack[-1] = $single;
3669 # Turn off all flags except single-stepping.
3672 # If we've gotten really deeply recursed, turn on the flag that will
3673 # make us stop with the 'deep recursion' message.
3674 $single |= 4 if $stack_depth == $deep;
3676 # If frame messages are on ...
3678 $frame & 4 # Extended frame entry message
3680 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3682 # Why -1? But it works! :-(
3683 # Because print_trace will call add 1 to it and then call
3684 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3686 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3688 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3690 # standard frame entry message
3694 # Determine the sub's return type,and capture approppriately.
3697 # Called in array context. call sub and capture output.
3698 # DB::DB will recursively get control again if appropriate; we'll come
3699 # back here when the sub is finished.
3702 eval { @ret = &$sub; };
3705 $signal = 1 unless $warnassertions;
3712 # Pop the single-step value back off the stack.
3713 $single |= $stack[ $stack_depth-- ];
3715 # Check for exit trace messages...
3717 $frame & 4 # Extended exit message
3719 print_lineinfo( ' ' x $stack_depth, "out " ),
3720 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3722 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3724 # Standard exit message
3728 # Print the return info if we need to.
3729 if ( $doret eq $stack_depth or $frame & 16 ) {
3731 # Turn off output record separator.
3733 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3735 # Indent if we're printing because of $frame tracing.
3736 print $fh ' ' x $stack_depth if $frame & 16;
3738 # Print the return value.
3739 print $fh "list context return from $sub:\n";
3740 dumpit( $fh, \@ret );
3742 # And don't print it again.
3744 } ## end if ($doret eq $stack_depth...
3745 # And we have to return the return value now.
3747 } ## end if (wantarray)
3755 # Save the value if it's wanted at all.
3760 $signal = 1 unless $warnassertions;
3762 $ret = undef unless defined wantarray;
3765 if ( defined wantarray ) {
3767 # Save the value if it's wanted at all.
3772 # Void return, explicitly.
3778 # Pop the single-step value off the stack.
3779 $single |= $stack[ $stack_depth-- ];
3781 # If we're doing exit messages...
3783 $frame & 4 # Extended messsages
3785 print_lineinfo( ' ' x $stack_depth, "out " ),
3786 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3788 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3794 # If we are supposed to show the return value... same as before.
3795 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
3797 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3798 print $fh ( ' ' x $stack_depth ) if $frame & 16;
3801 ? "scalar context return from $sub: "
3802 : "void context return from $sub\n"
3804 dumpit( $fh, $ret ) if defined wantarray;
3806 } ## end if ($doret eq $stack_depth...
3808 # Return the appropriate scalar value.
3810 } ## end else [ if (wantarray)
3813 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
3815 In Perl 5.8.0, there was a major realignment of the commands and what they did,
3816 Most of the changes were to systematize the command structure and to eliminate
3817 commands that threw away user input without checking.
3819 The following sections describe the code added to make it easy to support
3820 multiple command sets with conflicting command names. This section is a start
3821 at unifying all command processing to make it simpler to develop commands.
3823 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
3824 number, and C<$dbline> (the current line) as arguments.
3826 Support functions in this section which have multiple modes of failure C<die>
3827 on error; the rest simply return a false value.
3829 The user-interface functions (all of the C<cmd_*> functions) just output
3834 The C<%set> hash defines the mapping from command letter to subroutine
3837 C<%set> is a two-level hash, indexed by set name and then by command name.
3838 Note that trying to set the CommandSet to C<foobar> simply results in the
3839 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
3848 'A' => 'pre580_null',
3850 'B' => 'pre580_null',
3851 'd' => 'pre580_null',
3854 'M' => 'pre580_null',
3856 'o' => 'pre580_null',
3862 '<' => 'pre590_prepost',
3863 '<<' => 'pre590_prepost',
3864 '>' => 'pre590_prepost',
3865 '>>' => 'pre590_prepost',
3866 '{' => 'pre590_prepost',
3867 '{{' => 'pre590_prepost',
3871 =head2 C<cmd_wrapper()> (API)
3873 C<cmd_wrapper()> allows the debugger to switch command sets
3874 depending on the value of the C<CommandSet> option.
3876 It tries to look up the command in the C<%set> package-level I<lexical>
3877 (which means external entities can't fiddle with it) and create the name of
3878 the sub to call based on the value found in the hash (if it's there). I<All>
3879 of the commands to be handled in a set have to be added to C<%set>; if they
3880 aren't found, the 5.8.0 equivalent is called (if there is one).
3882 This code uses symbolic references.
3889 my $dblineno = shift;
3891 # Assemble the command subroutine's name by looking up the
3892 # command set and command name in %set. If we can't find it,
3893 # default to the older version of the command.
3895 . ( $set{$CommandSet}{$cmd}
3896 || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) );
3898 # Call the command subroutine, call it by name.
3899 return &$call( $cmd, $line, $dblineno );
3900 } ## end sub cmd_wrapper
3902 =head3 C<cmd_a> (command)
3904 The C<a> command handles pre-execution actions. These are associated with a
3905 particular line, so they're stored in C<%dbline>. We default to the current
3906 line if none is specified.
3912 my $line = shift || ''; # [.|line] expr
3915 # If it's dot (here), or not all digits, use the current line.
3916 $line =~ s/^(\.|(?:[^\d]))/$dbline/;
3918 # Should be a line number followed by an expression.
3919 if ( $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
3920 my ( $lineno, $expr ) = ( $1, $2 );
3922 # If we have an expression ...
3923 if ( length $expr ) {
3925 # ... but the line isn't breakable, complain.
3926 if ( $dbline[$lineno] == 0 ) {
3928 "Line $lineno($dbline[$lineno]) does not have an action?\n";
3932 # It's executable. Record that the line has an action.
3933 $had_breakpoints{$filename} |= 2;
3935 # Remove any action, temp breakpoint, etc.
3936 $dbline{$lineno} =~ s/\0[^\0]*//;
3938 # Add the action to the line.
3939 $dbline{$lineno} .= "\0" . action($expr);
3941 } ## end if (length $expr)
3942 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
3947 "Adding an action requires an optional lineno and an expression\n"
3952 =head3 C<cmd_A> (command)
3954 Delete actions. Similar to above, except the delete code is in a separate
3955 subroutine, C<delete_action>.
3961 my $line = shift || '';
3965 $line =~ s/^\./$dbline/;
3967 # Call delete_action with a null param to delete them all.
3968 # The '1' forces the eval to be true. It'll be false only
3969 # if delete_action blows up for some reason, in which case
3970 # we print $@ and get out.
3971 if ( $line eq '*' ) {
3972 eval { &delete_action(); 1 } or print $OUT $@ and return;
3975 # There's a real line number. Pass it to delete_action.
3976 # Error trapping is as above.
3977 elsif ( $line =~ /^(\S.*)/ ) {
3978 eval { &delete_action($1); 1 } or print $OUT $@ and return;
3981 # Swing and a miss. Bad syntax.
3984 "Deleting an action requires a line number, or '*' for all\n" ; # hint
3988 =head3 C<delete_action> (API)
3990 C<delete_action> accepts either a line number or C<undef>. If a line number
3991 is specified, we check for the line being executable (if it's not, it
3992 couldn't have had an action). If it is, we just take the action off (this
3993 will get any kind of an action, including breakpoints).
3999 if ( defined($i) ) {
4002 die "Line $i has no action .\n" if $dbline[$i] == 0;
4004 # Nuke whatever's there.
4005 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4006 delete $dbline{$i} if $dbline{$i} eq '';
4009 print $OUT "Deleting all actions...\n";
4010 for my $file ( keys %had_breakpoints ) {
4011 local *dbline = $main::{ '_<' . $file };
4014 for ( $i = 1 ; $i <= $max ; $i++ ) {
4015 if ( defined $dbline{$i} ) {
4016 $dbline{$i} =~ s/\0[^\0]*//;
4017 delete $dbline{$i} if $dbline{$i} eq '';
4019 unless ( $had_breakpoints{$file} &= ~2 ) {
4020 delete $had_breakpoints{$file};
4022 } ## end for ($i = 1 ; $i <= $max...
4023 } ## end for my $file (keys %had_breakpoints)
4024 } ## end else [ if (defined($i))
4025 } ## end sub delete_action
4027 =head3 C<cmd_b> (command)
4029 Set breakpoints. Since breakpoints can be set in so many places, in so many
4030 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4031 we try to parse the command type, and then shuttle it off to an appropriate
4032 subroutine to actually do the work of setting the breakpoint in the right
4039 my $line = shift; # [.|line] [cond]
4042 # Make . the current line number if it's there..
4043 $line =~ s/^\./$dbline/;
4045 # No line number, no condition. Simple break on current line.
4046 if ( $line =~ /^\s*$/ ) {
4047 &cmd_b_line( $dbline, 1 );
4050 # Break on load for a file.
4051 elsif ( $line =~ /^load\b\s*(.*)/ ) {
4057 # b compile|postpone <some sub> [<condition>]
4058 # The interpreter actually traps this one for us; we just put the
4059 # necessary condition in the %postponed hash.
4060 elsif ( $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4062 # Capture the condition if there is one. Make it true if none.
4063 my $cond = length $3 ? $3 : '1';
4065 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
4066 # if it was 'compile'.
4067 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
4069 # De-Perl4-ify the name - ' separators to ::.
4070 $subname =~ s/\'/::/g;
4072 # Qualify it into the current package unless it's already qualified.
4073 $subname = "${'package'}::" . $subname unless $subname =~ /::/;
4075 # Add main if it starts with ::.
4076 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4078 # Save the break type for this sub.
4079 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
4080 } ## end elsif ($line =~ ...
4082 # b <sub name> [<condition>]
4083 elsif ( $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4087 $cond = length $2 ? $2 : '1';
4088 &cmd_b_sub( $subname, $cond );
4091 # b <line> [<condition>].
4092 elsif ( $line =~ /^(\d*)\s*(.*)/ ) {
4094 # Capture the line. If none, it's the current line.
4095 $line = $1 || $dbline;
4097 # If there's no condition, make it '1'.
4098 $cond = length $2 ? $2 : '1';
4101 &cmd_b_line( $line, $cond );
4104 # Line didn't make sense.
4106 print "confused by line($line)?\n";
4110 =head3 C<break_on_load> (API)
4112 We want to break when this file is loaded. Mark this file in the
4113 C<%break_on_load> hash, and note that it has a breakpoint in
4114 C<%had_breakpoints>.
4120 $break_on_load{$file} = 1;
4121 $had_breakpoints{$file} |= 1;
4124 =head3 C<report_break_on_load> (API)
4126 Gives us an array of filenames that are set to break on load. Note that
4127 only files with break-on-load are in here, so simply showing the keys
4132 sub report_break_on_load {
4133 sort keys %break_on_load;
4136 =head3 C<cmd_b_load> (command)
4138 We take the file passed in and try to find it in C<%INC> (which maps modules
4139 to files they came from). We mark those files for break-on-load via
4140 C<break_on_load> and then report that it was done.
4148 # This is a block because that way we can use a redo inside it
4149 # even without there being any looping structure at all outside it.
4152 # Save short name and full path if found.
4154 push @files, $::INC{$file} if $::INC{$file};
4156 # Tack on .pm and do it again unless there was a '.' in the name
4158 $file .= '.pm', redo unless $file =~ /\./;
4161 # Do the real work here.
4162 break_on_load($_) for @files;
4164 # All the files that have break-on-load breakpoints.
4165 @files = report_break_on_load;
4167 # Normalize for the purposes of our printing this.
4170 print $OUT "Will stop on load of `@files'.\n";
4171 } ## end sub cmd_b_load
4173 =head3 C<$filename_error> (API package global)
4175 Several of the functions we need to implement in the API need to work both
4176 on the current file and on other files. We don't want to duplicate code, so
4177 C<$filename_error> is used to contain the name of the file that's being
4178 worked on (if it's not the current one).
4180 We can now build functions in pairs: the basic function works on the current
4181 file, and uses C<$filename_error> as part of its error message. Since this is
4182 initialized to C<"">, no filename will appear when we are working on the
4185 The second function is a wrapper which does the following:
4191 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4195 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4199 Calls the first function.
4201 The first function works on the I<current> file (i.e., the one we changed to),
4202 and prints C<$filename_error> in the error message (the name of the other file)
4203 if it needs to. When the functions return, C<*dbline> is restored to point
4204 to the actual current file (the one we're executing in) and
4205 C<$filename_error> is restored to C<"">. This restores everything to
4206 the way it was before the second function was called at all.
4208 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4215 $filename_error = '';
4217 =head3 breakable_line(from, to) (API)
4219 The subroutine decides whether or not a line in the current file is breakable.
4220 It walks through C<@dbline> within the range of lines specified, looking for
4221 the first line that is breakable.
4223 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4224 first line I<after> C<$to> that's breakable, if there is one.
4226 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4227 first line I<before> C<$to> that's breakable, if there is one.
4231 sub breakable_line {
4233 my ( $from, $to ) = @_;
4235 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4238 # If there are at least 2 arguments, we're trying to search a range.
4241 # $delta is positive for a forward search, negative for a backward one.
4242 my $delta = $from < $to ? +1 : -1;
4244 # Keep us from running off the ends of the file.
4245 my $limit = $delta > 0 ? $#dbline : 1;
4247 # Clever test. If you're a mathematician, it's obvious why this
4248 # test works. If not:
4249 # If $delta is positive (going forward), $limit will be $#dbline.
4250 # If $to is less than $limit, ($limit - $to) will be positive, times
4251 # $delta of 1 (positive), so the result is > 0 and we should use $to
4252 # as the stopping point.
4254 # If $to is greater than $limit, ($limit - $to) is negative,
4255 # times $delta of 1 (positive), so the result is < 0 and we should
4256 # use $limit ($#dbline) as the stopping point.
4258 # If $delta is negative (going backward), $limit will be 1.
4259 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4260 # (negative) so the result is > 0, and we use $to as the stopping
4263 # If $to is less than zero, ($limit - $to) will be positive,
4264 # times $delta of -1 (negative), so the result is not > 0, and
4265 # we use $limit (1) as the stopping point.
4267 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4268 # (negative), still giving zero; the result is not > 0, and
4269 # we use $limit (1) as the stopping point.
4271 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4272 # (negative), giving a positive (>0) value, so we'll set $limit to
4275 $limit = $to if ( $limit - $to ) * $delta > 0;
4277 # The real search loop.
4278 # $i starts at $from (the point we want to start searching from).
4279 # We move through @dbline in the appropriate direction (determined
4280 # by $delta: either -1 (back) or +1 (ahead).
4281 # We stay in as long as we haven't hit an executable line
4282 # ($dbline[$i] == 0 means not executable) and we haven't reached
4283 # the limit yet (test similar to the above).
4284 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4286 } ## end if (@_ >= 2)
4288 # If $i points to a line that is executable, return that.
4289 return $i unless $dbline[$i] == 0;
4291 # Format the message and print it: no breakable lines in range.
4292 my ( $pl, $upto ) = ( '', '' );
4293 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4295 # If there's a filename in filename_error, we'll see it.
4297 die "Line$pl $from$upto$filename_error not breakable\n";
4298 } ## end sub breakable_line
4300 =head3 breakable_line_in_filename(file, from, to) (API)
4302 Like C<breakable_line>, but look in another file.
4306 sub breakable_line_in_filename {
4308 # Capture the file name.
4311 # Swap the magic line array over there temporarily.
4312 local *dbline = $main::{ '_<' . $f };
4314 # If there's an error, it's in this other file.
4315 local $filename_error = " of `$f'";
4317 # Find the breakable line.
4320 # *dbline and $filename_error get restored when this block ends.
4322 } ## end sub breakable_line_in_filename
4324 =head3 break_on_line(lineno, [condition]) (API)
4326 Adds a breakpoint with the specified condition (or 1 if no condition was
4327 specified) to the specified line. Dies if it can't.
4332 my ( $i, $cond ) = @_;
4334 # Always true if no condition supplied.
4335 $cond = 1 unless @_ >= 2;
4341 # Woops, not a breakable line. $filename_error allows us to say
4342 # if it was in a different file.
4343 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4345 # Mark this file as having breakpoints in it.
4346 $had_breakpoints{$filename} |= 1;
4348 # If there is an action or condition here already ...
4349 if ( $dbline{$i} ) {
4351 # ... swap this condition for the existing one.
4352 $dbline{$i} =~ s/^[^\0]*/$cond/;
4356 # Nothing here - just add the condition.
4357 $dbline{$i} = $cond;
4359 } ## end sub break_on_line
4361 =head3 cmd_b_line(line, [condition]) (command)
4363 Wrapper for C<break_on_line>. Prints the failure message if it
4369 eval { break_on_line(@_); 1 } or do {
4371 print $OUT $@ and return;
4373 } ## end sub cmd_b_line
4375 =head3 break_on_filename_line(file, line, [condition]) (API)
4377 Switches to the file specified and then calls C<break_on_line> to set
4382 sub break_on_filename_line {
4383 my ( $f, $i, $cond ) = @_;
4385 # Always true if condition left off.
4386 $cond = 1 unless @_ >= 3;
4388 # Switch the magical hash temporarily.
4389 local *dbline = $main::{ '_<' . $f };
4391 # Localize the variables that break_on_line uses to make its message.
4392 local $filename_error = " of `$f'";
4393 local $filename = $f;
4395 # Add the breakpoint.
4396 break_on_line( $i, $cond );
4397 } ## end sub break_on_filename_line
4399 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4401 Switch to another file, search the range of lines specified for an
4402 executable one, and put a breakpoint on the first one you find.
4406 sub break_on_filename_line_range {
4407 my ( $f, $from, $to, $cond ) = @_;
4409 # Find a breakable line if there is one.
4410 my $i = breakable_line_in_filename( $f, $from, $to );
4412 # Always true if missing.
4413 $cond = 1 unless @_ >= 3;
4415 # Add the breakpoint.
4416 break_on_filename_line( $f, $i, $cond );
4417 } ## end sub break_on_filename_line_range
4419 =head3 subroutine_filename_lines(subname, [condition]) (API)
4421 Search for a subroutine within a given file. The condition is ignored.
4422 Uses C<find_sub> to locate the desired subroutine.
4426 sub subroutine_filename_lines {
4427 my ( $subname, $cond ) = @_;
4429 # Returned value from find_sub() is fullpathname:startline-endline.
4430 # The match creates the list (fullpathname, start, end). Falling off
4431 # the end of the subroutine returns this implicitly.
4432 find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/;
4433 } ## end sub subroutine_filename_lines
4435 =head3 break_subroutine(subname) (API)
4437 Places a break on the first line possible in the specified subroutine. Uses
4438 C<subroutine_filename_lines> to find the subroutine, and
4439 C<break_on_filename_line_range> to place the break.
4443 sub break_subroutine {
4444 my $subname = shift;
4446 # Get filename, start, and end.
4447 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
4448 or die "Subroutine $subname not found.\n";
4450 # Null condition changes to '1' (always true).
4451 $cond = 1 unless @_ >= 2;
4453 # Put a break the first place possible in the range of lines
4454 # that make up this subroutine.
4455 break_on_filename_line_range( $file, $s, $e, @_ );
4456 } ## end sub break_subroutine
4458 =head3 cmd_b_sub(subname, [condition]) (command)
4460 We take the incoming subroutine name and fully-qualify it as best we can.
4464 =item 1. If it's already fully-qualified, leave it alone.
4466 =item 2. Try putting it in the current package.
4468 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
4470 =item 4. If it starts with '::', put it in 'main::'.
4474 After all this cleanup, we call C<break_subroutine> to try to set the
4480 my ( $subname, $cond ) = @_;
4482 # Add always-true condition if we have none.
4483 $cond = 1 unless @_ >= 2;
4485 # If the subname isn't a code reference, qualify it so that
4486 # break_subroutine() will work right.
4487 unless ( ref $subname eq 'CODE' ) {
4490 $subname =~ s/\'/::/g;
4493 # Put it in this package unless it's already qualified.
4494 $subname = "${'package'}::" . $subname
4495 unless $subname =~ /::/;
4497 # Requalify it into CORE::GLOBAL if qualifying it into this
4498 # package resulted in its not being defined, but only do so
4499 # if it really is in CORE::GLOBAL.
4500 $subname = "CORE::GLOBAL::$s"
4501 if not defined &$subname
4503 and defined &{"CORE::GLOBAL::$s"};
4505 # Put it in package 'main' if it has a leading ::.
4506 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4508 } ## end unless (ref $subname eq 'CODE')
4510 # Try to set the breakpoint.
4511 eval { break_subroutine( $subname, $cond ); 1 } or do {
4513 print $OUT $@ and return;
4515 } ## end sub cmd_b_sub
4517 =head3 C<cmd_B> - delete breakpoint(s) (command)
4519 The command mostly parses the command line and tries to turn the argument
4520 into a line spec. If it can't, it uses the current line. It then calls
4521 C<delete_breakpoint> to actually do the work.
4523 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
4524 thereby deleting all the breakpoints.
4531 # No line spec? Use dbline.
4532 # If there is one, use it if it's non-zero, or wipe it out if it is.
4533 my $line = ( $_[0] =~ /^\./ ) ? $dbline : shift || '';
4536 # If the line was dot, make the line the current one.
4537 $line =~ s/^\./$dbline/;
4539 # If it's * we're deleting all the breakpoints.
4540 if ( $line eq '*' ) {
4541 eval { &delete_breakpoint(); 1 } or print $OUT $@ and return;
4544 # If there is a line spec, delete the breakpoint on that line.
4545 elsif ( $line =~ /^(\S.*)/ ) {
4546 eval { &delete_breakpoint( $line || $dbline ); 1 } or do {
4548 print $OUT $@ and return;
4550 } ## end elsif ($line =~ /^(\S.*)/)
4555 "Deleting a breakpoint requires a line number, or '*' for all\n"
4560 =head3 delete_breakpoint([line]) (API)
4562 This actually does the work of deleting either a single breakpoint, or all
4565 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
4566 just drop out with a message saying so. If it is, we remove the condition
4567 part of the 'condition\0action' that says there's a breakpoint here. If,
4568 after we've done that, there's nothing left, we delete the corresponding
4569 line in C<%dbline> to signal that no action needs to be taken for this line.
4571 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
4572 which lists all currently-loaded files which have breakpoints. We then look
4573 at each line in each of these files, temporarily switching the C<%dbline>
4574 and C<@dbline> structures to point to the files in question, and do what
4575 we did in the single line case: delete the condition in C<@dbline>, and
4576 delete the key in C<%dbline> if nothing's left.
4578 We then wholesale delete C<%postponed>, C<%postponed_file>, and
4579 C<%break_on_load>, because these structures contain breakpoints for files
4580 and code that haven't been loaded yet. We can just kill these off because there
4581 are no magical debugger structures associated with them.
4585 sub delete_breakpoint {
4588 # If we got a line, delete just that one.
4589 if ( defined($i) ) {
4591 # Woops. This line wasn't breakable at all.
4592 die "Line $i not breakable.\n" if $dbline[$i] == 0;
4594 # Kill the condition, but leave any action.
4595 $dbline{$i} =~ s/^[^\0]*//;
4597 # Remove the entry entirely if there's no action left.
4598 delete $dbline{$i} if $dbline{$i} eq '';
4601 # No line; delete them all.
4603 print $OUT "Deleting all breakpoints...\n";
4605 # %had_breakpoints lists every file that had at least one
4607 for my $file ( keys %had_breakpoints ) {
4609 # Switch to the desired file temporarily.
4610 local *dbline = $main::{ '_<' . $file };
4615 # For all lines in this file ...
4616 for ( $i = 1 ; $i <= $max ; $i++ ) {
4618 # If there's a breakpoint or action on this line ...
4619 if ( defined $dbline{$i} ) {
4621 # ... remove the breakpoint.
4622 $dbline{$i} =~ s/^[^\0]+//;
4623 if ( $dbline{$i} =~ s/^\0?$// ) {
4625 # Remove the entry altogether if no action is there.
4628 } ## end if (defined $dbline{$i...
4629 } ## end for ($i = 1 ; $i <= $max...
4631 # If, after we turn off the "there were breakpoints in this file"
4632 # bit, the entry in %had_breakpoints for this file is zero,
4633 # we should remove this file from the hash.
4634 if ( not $had_breakpoints{$file} &= ~1 ) {
4635 delete $had_breakpoints{$file};
4637 } ## end for my $file (keys %had_breakpoints)
4639 # Kill off all the other breakpoints that are waiting for files that
4640 # haven't been loaded yet.
4642 undef %postponed_file;
4643 undef %break_on_load;
4644 } ## end else [ if (defined($i))
4645 } ## end sub delete_breakpoint
4647 =head3 cmd_stop (command)
4649 This is meant to be part of the new command API, but it isn't called or used
4650 anywhere else in the debugger. XXX It is probably meant for use in development
4655 sub cmd_stop { # As on ^C, but not signal-safy.
4659 =head3 C<cmd_e> - threads
4661 Display the current thread id:
4665 This could be how (when implemented) to send commands to this thread id (e cmd)
4666 or that thread id (e tid cmd).
4673 unless (exists($INC{'threads.pm'})) {
4674 print "threads not loaded($ENV{PERL5DB_THREADED})
4675 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4677 my $tid = threads->tid;
4678 print "thread id: $tid\n";
4682 =head3 C<cmd_E> - list of thread ids
4684 Display the list of available thread ids:
4688 This could be used (when implemented) to send commands to all threads (E cmd).
4695 unless (exists($INC{'threads.pm'})) {
4696 print "threads not loaded($ENV{PERL5DB_THREADED})
4697 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4699 my $tid = threads->tid;
4700 print "thread ids: ".join(', ',
4701 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
4706 =head3 C<cmd_h> - help command (command)
4708 Does the work of either
4714 Showing all the debugger help
4718 Showing help for a specific command
4727 # If we have no operand, assume null.
4728 my $line = shift || '';
4730 # 'h h'. Print the long-format help.
4731 if ( $line =~ /^h\s*/ ) {
4735 # 'h <something>'. Search for the command and print only its help.
4736 elsif ( $line =~ /^(\S.*)$/ ) {
4738 # support long commands; otherwise bogus errors
4739 # happen when you ask for h on <CR> for example
4740 my $asked = $1; # the command requested
4741 # (for proper error message)
4743 my $qasked = quotemeta($asked); # for searching; we don't
4744 # want to use it as a pattern.
4745 # XXX: finds CR but not <CR>
4747 # Search the help string for the command.
4749 $help =~ /^ # Start of a line
4751 (?:[IB]<) # Optional markup
4752 $qasked # The requested command
4757 # It's there; pull it out and print it.
4761 (?:[IB]<) # Optional markup
4762 $qasked # The command
4763 ([\s\S]*?) # Description line(s)
4764 \n) # End of last description line
4765 (?!\s) # Next line not starting with
4774 # Not found; not a debugger command.
4776 print_help("B<$asked> is not a debugger command.\n");
4778 } ## end elsif ($line =~ /^(\S.*)$/)
4780 # 'h' - print the summary help.
4782 print_help($summary);
4786 =head3 C<cmd_i> - inheritance display
4788 Display the (nested) parentage of the module or object given.
4795 eval { require Class::ISA };
4797 &warn( $@ =~ /locate/
4798 ? "Class::ISA module not found - please install\n"
4803 foreach my $isa ( split( /\s+/, $line ) ) {
4809 map { # snaffled unceremoniously from Class::ISA
4812 defined( ${"$_\::VERSION"} )
4813 ? ' ' . ${"$_\::VERSION"}
4815 } Class::ISA::self_and_super_path(ref($isa) || $isa)
4822 =head3 C<cmd_l> - list lines (command)
4824 Most of the command is taken up with transforming all the different line
4825 specification syntaxes into 'start-stop'. After that is done, the command
4826 runs a loop over C<@dbline> for the specified range of lines. It handles
4827 the printing of each line and any markers (C<==E<gt>> for current line,
4828 C<b> for break on this line, C<a> for action on this line, C<:> for this
4831 We save the last line listed in the C<$start> global for further listing
4837 my $current_line = $line;
4841 # If this is '-something', delete any spaces after the dash.
4842 $line =~ s/^-\s*$/-/;
4844 # If the line is '$something', assume this is a scalar containing a
4846 if ( $line =~ /^(\$.*)/s ) {
4848 # Set up for DB::eval() - evaluate in *user* context.
4853 # Ooops. Bad scalar.
4854 print( $OUT "Error: $@\n" ), next CMD if $@;
4856 # Good scalar. If it's a reference, find what it points to.
4858 print( $OUT "Interpreted as: $1 $s\n" );
4861 # Call self recursively to really do the command.
4863 } ## end if ($line =~ /^(\$.*)/s)
4865 # l name. Try to find a sub by that name.
4866 elsif ( $line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s ) {
4867 my $s = $subname = $1;
4870 $subname =~ s/\'/::/;
4872 # Put it in this package unless it starts with ::.
4873 $subname = $package . "::" . $subname unless $subname =~ /::/;
4875 # Put it in CORE::GLOBAL if t doesn't start with :: and
4876 # it doesn't live in this package and it lives in CORE::GLOBAL.
4877 $subname = "CORE::GLOBAL::$s"
4878 if not defined &$subname
4880 and defined &{"CORE::GLOBAL::$s"};
4882 # Put leading '::' names into 'main::'.
4883 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4885 # Get name:start-stop from find_sub, and break this up at
4887 @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
4889 # Pull off start-stop.
4890 $subrange = pop @pieces;
4892 # If the name contained colons, the split broke it up.
4893 # Put it back together.
4894 $file = join( ':', @pieces );
4896 # If we're not in that file, switch over to it.
4897 if ( $file ne $filename ) {
4898 print $OUT "Switching to file '$file'.\n"
4899 unless $slave_editor;
4901 # Switch debugger's magic structures.
4902 *dbline = $main::{ '_<' . $file };
4905 } ## end if ($file ne $filename)
4907 # Subrange is 'start-stop'. If this is less than a window full,
4908 # swap it to 'start+', which will list a window from the start point.
4910 if ( eval($subrange) < -$window ) {
4911 $subrange =~ s/-.*/+/;
4914 # Call self recursively to list the range.
4916 &cmd_l( 'l', $subrange );
4917 } ## end if ($subrange)
4921 print $OUT "Subroutine $subname not found.\n";
4923 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
4926 elsif ( $line =~ /^\s*$/ ) {
4928 # Compute new range to list.
4929 $incr = $window - 1;
4930 $line = $start . '-' . ( $start + $incr );
4933 &cmd_l( 'l', $line );
4936 # l [start]+number_of_lines
4937 elsif ( $line =~ /^(\d*)\+(\d*)$/ ) {
4939 # Don't reset start for 'l +nnn'.
4942 # Increment for list. Use window size if not specified.
4943 # (Allows 'l +' to work.)
4945 $incr = $window - 1 unless $incr;
4947 # Create a line range we'll understand, and recurse to do it.
4948 $line = $start . '-' . ( $start + $incr );
4949 &cmd_l( 'l', $line );
4950 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
4952 # l start-stop or l start,stop
4953 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) {
4955 # Determine end point; use end of file if not specified.
4956 $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 );
4958 # Go on to the end, and then stop.
4959 $end = $max if $end > $max;
4961 # Determine start line.
4963 $i = $line if $i eq '.';
4967 # If we're running under a slave editor, force it to show the lines.
4968 if ($slave_editor) {
4969 print $OUT "\032\032$filename:$i:0\n";
4973 # We're doing it ourselves. We want to show the line and special
4975 # - the current line in execution
4976 # - whether a line is breakable or not
4977 # - whether a line has a break or not
4978 # - whether a line has an action or not
4980 for ( ; $i <= $end ; $i++ ) {
4982 # Check for breakpoints and actions.
4983 my ( $stop, $action );
4984 ( $stop, $action ) = split( /\0/, $dbline{$i} )
4987 # ==> if this is the current line in execution,
4988 # : if it's breakable.
4990 ( $i == $current_line and $filename eq $filename_ini )
4992 : ( $dbline[$i] + 0 ? ':' : ' ' );
4994 # Add break and action indicators.
4995 $arrow .= 'b' if $stop;
4996 $arrow .= 'a' if $action;
4999 print $OUT "$i$arrow\t", $dbline[$i];
5001 # Move on to the next line. Drop out on an interrupt.
5002 $i++, last if $signal;
5003 } ## end for (; $i <= $end ; $i++)
5005 # Line the prompt up; print a newline if the last line listed
5006 # didn't have a newline.
5007 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/;
5008 } ## end else [ if ($slave_editor)
5010 # Save the point we last listed to in case another relative 'l'
5011 # command is desired. Don't let it run off the end.
5013 $start = $max if $start > $max;
5014 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
5017 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5019 To list breakpoints, the command has to look determine where all of them are
5020 first. It starts a C<%had_breakpoints>, which tells us what all files have
5021 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5022 magic source and breakpoint data structures) to the file, and then look
5023 through C<%dbline> for lines with breakpoints and/or actions, listing them
5024 out. We look through C<%postponed> not-yet-compiled subroutines that have
5025 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5026 that have breakpoints.
5028 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5035 # If no argument, list everything. Pre-5.8.0 version always lists
5037 my $arg = shift || 'abw';
5038 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
5040 # See what is wanted.
5041 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0;
5042 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0;
5043 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0;
5045 # Breaks and actions are found together, so we look in the same place
5047 if ( $break_wanted or $action_wanted ) {
5049 # Look in all the files with breakpoints...
5050 for my $file ( keys %had_breakpoints ) {
5052 # Temporary switch to this file.
5053 local *dbline = $main::{ '_<' . $file };
5055 # Set up to look through the whole file.
5057 my $was; # Flag: did we print something
5060 # For each line in the file ...
5061 for ( $i = 1 ; $i <= $max ; $i++ ) {
5063 # We've got something on this line.
5064 if ( defined $dbline{$i} ) {
5066 # Print the header if we haven't.
5067 print $OUT "$file:\n" unless $was++;
5070 print $OUT " $i:\t", $dbline[$i];
5072 # Pull out the condition and the action.
5073 ( $stop, $action ) = split( /\0/, $dbline{$i} );
5075 # Print the break if there is one and it's wanted.
5076 print $OUT " break if (", $stop, ")\n"
5080 # Print the action if there is one and it's wanted.
5081 print $OUT " action: ", $action, "\n"
5085 # Quit if the user hit interrupt.
5087 } ## end if (defined $dbline{$i...
5088 } ## end for ($i = 1 ; $i <= $max...
5089 } ## end for my $file (keys %had_breakpoints)
5090 } ## end if ($break_wanted or $action_wanted)
5092 # Look for breaks in not-yet-compiled subs:
5093 if ( %postponed and $break_wanted ) {
5094 print $OUT "Postponed breakpoints in subroutines:\n";
5096 for $subname ( keys %postponed ) {
5097 print $OUT " $subname\t$postponed{$subname}\n";
5100 } ## end if (%postponed and $break_wanted)
5102 # Find files that have not-yet-loaded breaks:
5103 my @have = map { # Combined keys
5104 keys %{ $postponed_file{$_} }
5105 } keys %postponed_file;
5107 # If there are any, list them.
5108 if ( @have and ( $break_wanted or $action_wanted ) ) {
5109 print $OUT "Postponed breakpoints in files:\n";
5110 my ( $file, $line );
5112 for $file ( keys %postponed_file ) {
5113 my $db = $postponed_file{$file};
5114 print $OUT " $file:\n";
5115 for $line ( sort { $a <=> $b } keys %$db ) {
5116 print $OUT " $line:\n";
5117 my ( $stop, $action ) = split( /\0/, $$db{$line} );
5118 print $OUT " break if (", $stop, ")\n"
5121 print $OUT " action: ", $action, "\n"
5125 } ## end for $line (sort { $a <=>...
5127 } ## end for $file (keys %postponed_file)
5128 } ## end if (@have and ($break_wanted...
5129 if ( %break_on_load and $break_wanted ) {
5130 print $OUT "Breakpoints on load:\n";
5132 for $file ( keys %break_on_load ) {
5133 print $OUT " $file\n";
5136 } ## end if (%break_on_load and...
5137 if ($watch_wanted) {
5139 print $OUT "Watch-expressions:\n" if @to_watch;
5140 for my $expr (@to_watch) {
5141 print $OUT " $expr\n";
5144 } ## end if ($trace & 2)
5145 } ## end if ($watch_wanted)
5148 =head3 C<cmd_M> - list modules (command)
5150 Just call C<list_modules>.
5158 =head3 C<cmd_o> - options (command)
5160 If this is just C<o> by itself, we list the current settings via
5161 C<dump_option>. If there's a nonblank value following it, we pass that on to
5162 C<parse_options> for processing.
5168 my $opt = shift || ''; # opt[=val]
5170 # Nonblank. Try to parse and process.
5171 if ( $opt =~ /^(\S.*)/ ) {
5175 # Blank. List the current option settings.
5183 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5185 Advises the user that the O command has been renamed.
5190 print $OUT "The old O command is now the o command.\n"; # hint
5191 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5192 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5195 =head3 C<cmd_v> - view window (command)
5197 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5198 move back a few lines to list the selected line in context. Uses C<cmd_l>
5199 to do the actual listing after figuring out the range of line to request.
5207 # Extract the line to list around. (Astute readers will have noted that
5208 # this pattern will match whether or not a numeric line is specified,
5209 # which means that we'll always enter this loop (though a non-numeric
5210 # argument results in no action at all)).
5211 if ( $line =~ /^(\d*)$/ ) {
5213 # Total number of lines to list (a windowful).
5214 $incr = $window - 1;
5216 # Set the start to the argument given (if there was one).
5219 # Back up by the context amount.
5222 # Put together a linespec that cmd_l will like.
5223 $line = $start . '-' . ( $start + $incr );
5226 &cmd_l( 'l', $line );
5227 } ## end if ($line =~ /^(\d*)$/)
5230 =head3 C<cmd_w> - add a watch expression (command)
5232 The 5.8 version of this command adds a watch expression if one is specified;
5233 it does nothing if entered with no operands.
5235 We extract the expression, save it, evaluate it in the user's context, and
5236 save the value. We'll re-evaluate it each time the debugger passes a line,
5237 and will stop (see the code at the top of the command loop) if the value
5238 of any of the expressions changes.
5245 # Null expression if no arguments.
5246 my $expr = shift || '';
5248 # If expression is not null ...
5249 if ( $expr =~ /^(\S.*)/ ) {
5252 push @to_watch, $expr;
5254 # Parameterize DB::eval and call it to get the expression's value
5255 # in the user's context. This version can handle expressions which
5256 # return a list value.
5258 my ($val) = join( ' ', &eval );
5259 $val = ( defined $val ) ? "'$val'" : 'undef';
5261 # Save the current value of the expression.
5262 push @old_watch, $val;
5264 # We are now watching expressions.
5266 } ## end if ($expr =~ /^(\S.*)/)
5268 # You have to give one to get one.
5270 print $OUT "Adding a watch-expression requires an expression\n"; # hint
5274 =head3 C<cmd_W> - delete watch expressions (command)
5276 This command accepts either a watch expression to be removed from the list
5277 of watch expressions, or C<*> to delete them all.
5279 If C<*> is specified, we simply empty the watch expression list and the
5280 watch expression value list. We also turn off the bit that says we've got
5283 If an expression (or partial expression) is specified, we pattern-match
5284 through the expressions and remove the ones that match. We also discard
5285 the corresponding values. If no watch expressions are left, we turn off
5286 the I<watching expressions> bit.
5292 my $expr = shift || '';
5295 if ( $expr eq '*' ) {
5300 print $OUT "Deleting all watch expressions ...\n";
5303 @to_watch = @old_watch = ();
5306 # Delete one of them.
5307 elsif ( $expr =~ /^(\S.*)/ ) {
5309 # Where we are in the list.
5312 # For each expression ...
5313 foreach (@to_watch) {
5314 my $val = $to_watch[$i_cnt];
5316 # Does this one match the command argument?
5317 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
5318 # Yes. Turn it off, and its value too.
5319 splice( @to_watch, $i_cnt, 1 );
5320 splice( @old_watch, $i_cnt, 1 );
5323 } ## end foreach (@to_watch)
5325 # We don't bother to turn watching off because
5326 # a) we don't want to stop calling watchfunction() it it exists
5327 # b) foreach over a null list doesn't do anything anyway
5329 } ## end elsif ($expr =~ /^(\S.*)/)
5331 # No command arguments entered.
5334 "Deleting a watch-expression requires an expression, or '*' for all\n"
5339 ### END of the API section
5341 =head1 SUPPORT ROUTINES
5343 These are general support routines that are used in a number of places
5344 throughout the debugger.
5350 Something to do with assertions
5357 unless ($ini_assertion) {
5358 print $OUT "Assertions not supported in this Perl interpreter\n";
5360 if ( $cmd =~ /^.\b\s*([+-]?)\s*(~?)\s*(\w+(\s*\|\s*\w+)*)\s*$/ ) {
5361 my ( $how, $neg, $flags ) = ( $1, $2, $3 );
5362 my $acu = parse_DollarCaretP_flags($flags);
5363 if ( defined $acu ) {
5364 $acu = ~$acu if $neg;
5365 if ( $how eq '+' ) { $^P |= $acu }
5366 elsif ( $how eq '-' ) { $^P &= ~$acu }
5370 # else { print $OUT "undefined acu\n" }
5372 my $expanded = expand_DollarCaretP_flags($^P);
5373 print $OUT "Internal Perl debugger flags:\n\$^P=$expanded\n";
5380 save() saves the user's versions of globals that would mess us up in C<@saved>,
5381 and installs the versions we like better.
5387 # Save eval failure, command failure, extended OS error, output field
5388 # separator, input record separator, output record separator and
5389 # the warning setting.
5390 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
5392 $, = ""; # output field separator is null string
5393 $/ = "\n"; # input record separator is newline
5394 $\ = ""; # output record separator is null string
5395 $^W = 0; # warnings are off
5398 =head2 C<print_lineinfo> - show where we are now
5400 print_lineinfo prints whatever it is that it is handed; it prints it to the
5401 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5402 us to feed line information to a slave editor without messing up the
5407 sub print_lineinfo {
5409 # Make the terminal sensible if we're not the primary debugger.
5410 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5414 } ## end sub print_lineinfo
5416 =head2 C<postponed_sub>
5418 Handles setting postponed breakpoints in subroutines once they're compiled.
5419 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5420 range for the subroutine, then mark the file as having a breakpoint,
5421 temporarily switch the C<*dbline> glob over to the source file, and then
5422 search the given range of lines to find a breakable line. If we find one,
5423 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
5427 # The following takes its argument via $evalarg to preserve current @_
5431 # Get the subroutine name.
5432 my $subname = shift;
5434 # If this is a 'break +<n> if <condition>' ...
5435 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
5437 # If there's no offset, use '+0'.
5438 my $offset = $1 || 0;
5440 # find_sub's value is 'fullpath-filename:start-stop'. It's
5441 # possible that the filename might have colons in it too.
5442 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
5445 # We got the start line. Add the offset '+<n>' from
5446 # $postponed{subname}.
5449 # Switch to the file this sub is in, temporarily.
5450 local *dbline = $main::{ '_<' . $file };
5452 # No warnings, please.
5453 local $^W = 0; # != 0 is magical below
5455 # This file's got a breakpoint in it.
5456 $had_breakpoints{$file} |= 1;
5458 # Last line in file.
5461 # Search forward until we hit a breakable line or get to
5462 # the end of the file.
5463 ++$i until $dbline[$i] != 0 or $i >= $max;
5465 # Copy the breakpoint in and delete it from %postponed.
5466 $dbline{$i} = delete $postponed{$subname};
5469 # find_sub didn't find the sub.
5472 print $OUT "Subroutine $subname not found.\n";
5475 } ## end if ($postponed{$subname...
5476 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
5478 #print $OUT "In postponed_sub for `$subname'.\n";
5479 } ## end sub postponed_sub
5483 Called after each required file is compiled, but before it is executed;
5484 also called if the name of a just-compiled subroutine is a key of
5485 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
5486 etc.) into the just-compiled code.
5488 If this is a C<require>'d file, the incoming parameter is the glob
5489 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
5491 If it's a subroutine, the incoming parameter is the subroutine name.
5497 # If there's a break, process it.
5498 if ($ImmediateStop) {
5500 # Right, we've stopped. Turn it off.
5503 # Enter the command loop when DB::DB gets called.
5507 # If this is a subroutine, let postponed_sub() deal with it.
5508 return &postponed_sub unless ref \$_[0] eq 'GLOB';
5510 # Not a subroutine. Deal with the file.
5511 local *dbline = shift;
5512 my $filename = $dbline;
5513 $filename =~ s/^_<//;
5515 $signal = 1, print $OUT "'$filename' loaded...\n"
5516 if $break_on_load{$filename};
5517 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
5519 # Do we have any breakpoints to put in this file?
5520 return unless $postponed_file{$filename};
5522 # Yes. Mark this file as having breakpoints.
5523 $had_breakpoints{$filename} |= 1;
5525 # "Cannot be done: unsufficient magic" - we can't just put the
5526 # breakpoints saved in %postponed_file into %dbline by assigning
5527 # the whole hash; we have to do it one item at a time for the
5528 # breakpoints to be set properly.
5529 #%dbline = %{$postponed_file{$filename}};
5531 # Set the breakpoints, one at a time.
5534 for $key ( keys %{ $postponed_file{$filename} } ) {
5536 # Stash the saved breakpoint into the current file's magic line array.
5537 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
5540 # This file's been compiled; discard the stored breakpoints.
5541 delete $postponed_file{$filename};
5543 } ## end sub postponed
5547 C<dumpit> is the debugger's wrapper around dumpvar.pl.
5549 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
5550 a reference to a variable (the thing to be dumped) as its input.
5552 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
5553 the currently-selected filehandle, thank you very much). The current
5554 values of the package globals C<$single> and C<$trace> are backed up in
5555 lexicals, and they are turned off (this keeps the debugger from trying
5556 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
5557 preserve its current value and it is set to zero to prevent entry/exit
5558 messages from printing, and C<$doret> is localized as well and set to -2 to
5559 prevent return values from being shown.
5561 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
5562 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
5563 installed version in C<@INC>, yours will be used instead. Possible security
5566 It then checks to see if the subroutine C<main::dumpValue> is now defined
5567 (it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
5568 localizes the globals necessary for things to be sane when C<main::dumpValue()>
5569 is called, and picks up the variable to be dumped from the parameter list.
5571 It checks the package global C<%options> to see if there's a C<dumpDepth>
5572 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
5573 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
5574 structure: -1 means dump everything.
5576 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
5579 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
5580 and we then return to the caller.
5586 # Save the current output filehandle and switch to the one
5587 # passed in as the first parameter.
5588 local ($savout) = select(shift);
5590 # Save current settings of $single and $trace, and then turn them off.
5591 my $osingle = $single;
5592 my $otrace = $trace;
5593 $single = $trace = 0;
5595 # XXX Okay, what do $frame and $doret do, again?
5599 # Load dumpvar.pl unless we've already got the sub we need from it.
5600 unless ( defined &main::dumpValue ) {
5601 do 'dumpvar.pl' or die $@;
5604 # If the load succeeded (or we already had dumpvalue()), go ahead
5606 if ( defined &main::dumpValue ) {
5611 my $maxdepth = shift || $option{dumpDepth};
5612 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
5613 &main::dumpValue( $v, $maxdepth );
5614 } ## end if (defined &main::dumpValue)
5616 # Oops, couldn't load dumpvar.pl.
5619 print $OUT "dumpvar.pl not available.\n";
5622 # Reset $single and $trace to their old values.
5626 # Restore the old filehandle.
5630 =head2 C<print_trace>
5632 C<print_trace>'s job is to print a stack trace. It does this via the
5633 C<dump_trace> routine, which actually does all the ferreting-out of the
5634 stack trace data. C<print_trace> takes care of formatting it nicely and
5635 printing it to the proper filehandle.
5643 The filehandle to print to.
5647 How many frames to skip before starting trace.
5651 How many frames to print.
5655 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
5659 The original comment below seems to be noting that the traceback may not be
5660 correct if this routine is called in a tied method.
5664 # Tied method do not create a context, so may get wrong message:
5670 # If this is going to a slave editor, but we're not the primary
5671 # debugger, reset it first.
5673 if $fh eq $LINEINFO # slave editor
5674 and $LINEINFO eq $OUT # normal output
5675 and $term_pid != $$; # not the primary
5677 # Collect the actual trace information to be formatted.
5678 # This is an array of hashes of subroutine call info.
5679 my @sub = dump_trace( $_[0] + 1, $_[1] );
5681 # Grab the "short report" flag from @_.
5682 my $short = $_[2]; # Print short report, next one for sub name
5684 # Run through the traceback info, format it, and print it.
5686 for ( $i = 0 ; $i <= $#sub ; $i++ ) {
5688 # Drop out if the user has lost interest and hit control-C.
5691 # Set the separator so arrys print nice.
5694 # Grab and stringify the arguments if they are there.
5696 defined $sub[$i]{args}
5697 ? "(@{ $sub[$i]{args} })"
5700 # Shorten them up if $maxtrace says they're too long.
5701 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
5702 if length $args > $maxtrace;
5704 # Get the file name.
5705 my $file = $sub[$i]{file};
5707 # Put in a filename header if short is off.
5708 $file = $file eq '-e' ? $file : "file `$file'" unless $short;
5710 # Get the actual sub's name, and shorten to $maxtrace's requirement.
5712 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
5714 # Short report uses trimmed file and sub names.
5716 my $sub = @_ >= 4 ? $_[3] : $s;
5717 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
5718 } ## end if ($short)
5720 # Non-short report includes full names.
5722 print $fh "$sub[$i]{context} = $s$args"
5723 . " called from $file"
5724 . " line $sub[$i]{line}\n";
5726 } ## end for ($i = 0 ; $i <= $#sub...
5727 } ## end sub print_trace
5729 =head2 dump_trace(skip[,count])
5731 Actually collect the traceback information available via C<caller()>. It does
5732 some filtering and cleanup of the data, but mostly it just collects it to
5733 make C<print_trace()>'s job easier.
5735 C<skip> defines the number of stack frames to be skipped, working backwards
5736 from the most current. C<count> determines the total number of frames to
5737 be returned; all of them (well, the first 10^9) are returned if C<count>
5740 This routine returns a list of hashes, from most-recent to least-recent
5741 stack frame. Each has the following keys and values:
5745 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
5747 =item * C<sub> - subroutine name, or C<eval> information
5749 =item * C<args> - undef, or a reference to an array of arguments
5751 =item * C<file> - the file in which this item was defined (if any)
5753 =item * C<line> - the line on which it was defined
5761 # How many levels to skip.
5764 # How many levels to show. (1e9 is a cheap way of saying "all of them";
5765 # it's unlikely that we'll have more than a billion stack frames. If you
5766 # do, you've got an awfully big machine...)
5767 my $count = shift || 1e9;
5769 # We increment skip because caller(1) is the first level *back* from
5770 # the current one. Add $skip to the count of frames so we have a
5771 # simple stop criterion, counting from $skip to $count+$skip.
5775 # These variables are used to capture output from caller();
5776 my ( $p, $file, $line, $sub, $h, $context );
5778 my ( $e, $r, @a, @sub, $args );
5780 # XXX Okay... why'd we do that?
5781 my $nothard = not $frame & 8;
5784 # Do not want to trace this.
5785 my $otrace = $trace;
5788 # Start out at the skip count.
5789 # If we haven't reached the number of frames requested, and caller() is
5790 # still returning something, stay in the loop. (If we pass the requested
5791 # number of stack frames, or we run out - caller() returns nothing - we
5793 # Up the stack frame index to go back one more level each time.
5797 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
5802 # Go through the arguments and save them for later.
5806 if ( not defined $arg ) { # undefined parameter
5810 elsif ( $nothard and tied $arg ) { # tied parameter
5813 elsif ( $nothard and $type = ref $arg ) { # reference
5814 push @a, "ref($type)";
5816 else { # can be stringified
5818 "$arg"; # Safe to stringify now - should not call f().
5820 # Backslash any single-quotes or backslashes.
5823 # Single-quote it unless it's a number or a colon-separated
5826 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
5828 # Turn high-bit characters into meta-whatever.
5829 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
5831 # Turn control characters into ^-whatever.
5832 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
5835 } ## end else [ if (not defined $arg)
5836 } ## end for $arg (@args)
5838 # If context is true, this is array (@)context.
5839 # If context is false, this is scalar ($) context.
5840 # If neither, context isn't defined. (This is apparently a 'can't
5842 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
5844 # if the sub has args ($h true), make an anonymous array of the
5846 $args = $h ? [@a] : undef;
5848 # remove trailing newline-whitespace-semicolon-end of line sequence
5849 # from the eval text, if any.
5850 $e =~ s/\n\s*\;\s*\Z// if $e;
5852 # Escape backslashed single-quotes again if necessary.
5853 $e =~ s/([\\\'])/\\$1/g if $e;
5855 # if the require flag is true, the eval text is from a require.
5857 $sub = "require '$e'";
5860 # if it's false, the eval text is really from an eval.
5861 elsif ( defined $r ) {
5865 # If the sub is '(eval)', this is a block eval, meaning we don't
5866 # know what the eval'ed text actually was.
5867 elsif ( $sub eq '(eval)' ) {
5868 $sub = "eval {...}";
5871 # Stick the collected information into @sub as an anonymous hash.
5875 context => $context,
5883 # Stop processing frames if the user hit control-C.
5885 } ## end for ($i = $skip ; $i < ...
5887 # Restore the trace value again.
5890 } ## end sub dump_trace
5894 C<action()> takes input provided as the argument to an add-action command,
5895 either pre- or post-, and makes sure it's a complete command. It doesn't do
5896 any fancy parsing; it just keeps reading input until it gets a string
5897 without a trailing backslash.
5904 while ( $action =~ s/\\$// ) {
5906 # We have a backslash on the end. Read more.
5908 } ## end while ($action =~ s/\\$//)
5910 # Return the assembled action.
5916 This routine mostly just packages up a regular expression to be used
5917 to check that the thing it's being matched against has properly-matched
5920 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
5921 speeds things up by only creating the qr//'ed expression once; if it's
5922 already defined, we don't try to define it again. A speed hack.
5928 # I hate using globals!
5929 $balanced_brace_re ||= qr{
5932 (?> [^{}] + ) # Non-parens without backtracking
5934 (??{ $balanced_brace_re }) # Group with matching parens
5938 return $_[0] !~ m/$balanced_brace_re/;
5939 } ## end sub unbalanced
5943 C<gets()> is a primitive (very primitive) routine to read continuations.
5944 It was devised for reading continuations for actions.
5945 it just reads more input with C<readline()> and returns it.
5950 &readline("cont: ");
5953 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger
5955 The C<system()> function assumes that it can just go ahead and use STDIN and
5956 STDOUT, but under the debugger, we want it to use the debugger's input and
5959 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes
5960 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
5961 and then puts everything back again.
5967 # We save, change, then restore STDIN and STDOUT to avoid fork() since
5968 # some non-Unix systems can do system() but have problems with fork().
5969 open( SAVEIN, "<&STDIN" ) || &warn("Can't save STDIN");
5970 open( SAVEOUT, ">&STDOUT" ) || &warn("Can't save STDOUT");
5971 open( STDIN, "<&IN" ) || &warn("Can't redirect STDIN");
5972 open( STDOUT, ">&OUT" ) || &warn("Can't redirect STDOUT");
5974 # XXX: using csh or tcsh destroys sigint retvals!
5976 open( STDIN, "<&SAVEIN" ) || &warn("Can't restore STDIN");
5977 open( STDOUT, ">&SAVEOUT" ) || &warn("Can't restore STDOUT");
5981 # most of the $? crud was coping with broken cshisms
5983 &warn( "(Command exited ", ( $? >> 8 ), ")\n" );
5987 "(Command died of SIG#",
5989 ( ( $? & 128 ) ? " -- core dumped" : "" ),
5998 =head1 TTY MANAGEMENT
6000 The subs here do some of the terminal management for multiple debuggers.
6004 Top-level function called when we want to set up a new terminal for use
6007 If the C<noTTY> debugger option was set, we'll either use the terminal
6008 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6009 to find one. If we're a forked debugger, we call C<resetterm> to try to
6010 get a whole new terminal if we can.
6012 In either case, we set up the terminal next. If the C<ReadLine> option was
6013 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6014 the appropriate attributes. We then
6020 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6023 eval { require Term::ReadLine } or die $@;
6025 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6028 my ( $i, $o ) = split $tty, /,/;
6029 $o = $i unless defined $o;
6030 open( IN, "<$i" ) or die "Cannot open TTY `$i' for read: $!";
6031 open( OUT, ">$o" ) or die "Cannot open TTY `$o' for write: $!";
6034 my $sel = select($OUT);
6039 # We don't have a TTY - try to find one via Term::Rendezvous.
6041 eval "require Term::Rendezvous;" or die;
6043 # See if we have anything to pass to Term::Rendezvous.
6044 # Use $HOME/.perldbtty$$ if not.
6045 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6047 # Rendezvous and get the filehandles.
6048 my $term_rv = new Term::Rendezvous $rv;
6050 $OUT = $term_rv->OUT;
6051 } ## end else [ if ($tty)
6052 } ## end if ($notty)
6054 # We're a daughter debugger. Try to fork off another TTY.
6055 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6059 # If we shouldn't use Term::ReadLine, don't.
6061 $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT;
6064 # We're using Term::ReadLine. Get all the attributes for this terminal.
6066 $term = new Term::ReadLine 'perldb', $IN, $OUT;
6068 $rl_attribs = $term->Attribs;
6069 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6070 if defined $rl_attribs->{basic_word_break_characters}
6071 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6072 $rl_attribs->{special_prefixes} = '$@&%';
6073 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6074 $rl_attribs->{completion_function} = \&db_complete;
6075 } ## end else [ if (!$rl)
6077 # Set up the LINEINFO filehandle.
6078 $LINEINFO = $OUT unless defined $LINEINFO;
6079 $lineinfo = $console unless defined $lineinfo;
6085 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6086 $term->SetHistory(@hist);
6089 # XXX Ornaments are turned on unconditionally, which is not
6090 # always a good thing.
6091 ornaments($ornaments) if defined $ornaments;
6093 } ## end sub setterm
6096 $histfile //= option_val("HistFile", undef);
6097 return unless defined $histfile;
6098 open my $fh, "<", $histfile or return;
6109 return unless defined $histfile;
6110 eval { require File::Path } or return;
6111 eval { require File::Basename } or return;
6112 File::Path::mkpath(File::Basename::dirname($histfile));
6113 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6114 $histsize //= option_val("HistSize",100);
6115 my @copy = grep { $_ ne '?' } @hist;
6116 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6117 for ($start .. $#copy) {
6118 print $fh "$copy[$_]\n";
6120 close $fh or die "Could not write '$histfile': $!";
6123 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6125 When the process being debugged forks, or the process invokes a command
6126 via C<system()> which starts a new debugger, we need to be able to get a new
6127 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6128 fight over the terminal, and you can never quite be sure who's going to get the
6129 input you're typing.
6131 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6132 is tasked with doing all the necessary operating system mojo to get a new
6133 TTY (and probably another window) and to direct the new debugger to read and
6136 The debugger provides C<get_fork_TTY> functions which work for X Windows,
6137 OS/2, and Mac OS X. Other systems are not supported. You are encouraged
6138 to write C<get_fork_TTY> functions which work for I<your> platform
6139 and contribute them.
6141 =head3 C<xterm_get_fork_TTY>
6143 This function provides the C<get_fork_TTY> function for X windows. If a
6144 program running under the debugger forks, a new <xterm> window is opened and
6145 the subsidiary debugger is directed there.
6147 The C<open()> call is of particular note here. We have the new C<xterm>
6148 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6149 command (which prints the device name of the TTY we'll want to use for input
6150 and output to STDOUT, then C<sleep> for a very long time, routing this output
6151 to file number 3. This way we can simply read from the <XT> filehandle (which
6152 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6154 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6159 sub xterm_get_fork_TTY {
6160 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6162 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6165 # Get the output from 'tty' and clean it up a little.
6169 $pidprompt = ''; # Shown anyway in titlebar
6171 # There's our new TTY.
6173 } ## end sub xterm_get_fork_TTY
6175 =head3 C<os2_get_fork_TTY>
6177 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6181 # This example function resets $IN, $OUT itself
6183 sub os2_get_fork_TTY { # A simplification of the following (and works without):
6185 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6186 my %opt = ( title => "Daughter Perl debugger $pids $name",
6187 ($rl ? (read_by_key => 1) : ()) );
6188 require OS2::Process;
6189 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
6191 $pidprompt = ''; # Shown anyway in titlebar
6192 reset_IN_OUT($in, $out);
6194 return ''; # Indicate that reset_IN_OUT is called
6195 } ## end sub os2_get_fork_TTY
6197 =head3 C<macosx_get_fork_TTY>
6199 The Mac OS X version uses AppleScript to tell Terminal.app to create
6204 # Notes about Terminal.app's AppleScript support,
6205 # (aka things that might break in future OS versions).
6207 # The "do script" command doesn't return a reference to the new window
6208 # it creates, but since it appears frontmost and windows are enumerated
6209 # front to back, we can use "first window" === "window 1".
6211 # There's no direct accessor for the tty device name, so we fiddle
6212 # with the window title options until it says what we want.
6214 # Since "do script" is implemented by supplying the argument (plus a
6215 # return character) as terminal input, there's a potential race condition
6216 # where the debugger could beat the shell to reading the command.
6217 # To prevent this, we wait for the screen to clear before proceeding.
6219 # Tested and found to be functional in Mac OS X 10.3.9 and 10.4.8.
6221 sub macosx_get_fork_TTY
6225 return unless open($pipe,'-|','/usr/bin/osascript','-e',<<'__SCRIPT__');
6226 tell application "Terminal"
6227 do script "clear;exec sleep 100000"
6229 set title displays shell path to false
6230 set title displays window size to false
6231 set title displays file name to false
6232 set title displays device name to true
6233 set title displays custom title to true
6234 set custom title to ""
6235 copy name to thetitle
6236 set custom title to "forked perl debugger"
6237 repeat while (length of first paragraph of (get contents)) > 0
6245 $tty=readline($pipe);
6247 return unless defined($tty) && $tty =~ m(^/dev/);
6252 =head2 C<create_IN_OUT($flags)>
6254 Create a new pair of filehandles, pointing to a new TTY. If impossible,
6255 try to diagnose why.
6261 =item * 1 - Don't know how to create a new TTY.
6263 =item * 2 - Debugger has forked, but we can't get a new TTY.
6265 =item * 4 - standard debugger startup is happening.
6271 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
6273 # If we know how to get a new TTY, do it! $in will have
6274 # the TTY name if get_fork_TTY works.
6275 my $in = &get_fork_TTY if defined &get_fork_TTY;
6277 # It used to be that
6278 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
6280 if ( not defined $in ) {
6283 # We don't know how.
6284 print_help(<<EOP) if $why == 1;
6285 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6289 print_help(<<EOP) if $why == 2;
6290 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6291 This may be an asynchronous session, so the parent debugger may be active.
6294 # Note that both debuggers are fighting over the same input.
6295 print_help(<<EOP) if $why != 4;
6296 Since two debuggers fight for the same TTY, input is severely entangled.
6300 I know how to switch the output to a different window in xterms, OS/2
6301 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
6302 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
6303 B<DB::get_fork_TTY()> returning this.
6305 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6306 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6309 } ## end if (not defined $in)
6310 elsif ( $in ne '' ) {
6314 $console = ''; # Indicate no need to open-from-the-console
6317 } ## end sub create_IN_OUT
6321 Handles rejiggering the prompt when we've forked off a new debugger.
6323 If the new debugger happened because of a C<system()> that invoked a
6324 program under the debugger, the arrow between the old pid and the new
6325 in the prompt has I<two> dashes instead of one.
6327 We take the current list of pids and add this one to the end. If there
6328 isn't any list yet, we make one up out of the initial pid associated with
6329 the terminal and our new pid, sticking an arrow (either one-dashed or
6330 two dashed) in between them.
6332 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6333 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6338 sub resetterm { # We forked, so we need a different TTY
6340 # Needs to be passed to create_IN_OUT() as well.
6343 # resetterm(2): got in here because of a system() starting a debugger.
6344 # resetterm(1): just forked.
6345 my $systemed = $in > 1 ? '-' : '';
6347 # If there's already a list of pids, add this to the end.
6349 $pids =~ s/\]/$systemed->$$]/;
6352 # No pid list. Time to make one.
6354 $pids = "[$term_pid->$$]";
6357 # The prompt we're going to be using for this debugger.
6360 # We now 0wnz this terminal.
6363 # Just return if we're not supposed to try to create a new TTY.
6364 return unless $CreateTTY & $in;
6366 # Try to create a new IN/OUT pair.
6368 } ## end sub resetterm
6372 First, we handle stuff in the typeahead buffer. If there is any, we shift off
6373 the next line, print a message saying we got it, add it to the terminal
6374 history (if possible), and return it.
6376 If there's nothing in the typeahead buffer, check the command filehandle stack.
6377 If there are any filehandles there, read from the last one, and return the line
6378 if we got one. If not, we pop the filehandle off and close it, and try the
6379 next one up the stack.
6381 If we've emptied the filehandle stack, we check to see if we've got a socket
6382 open, and we read that and return it if we do. If we don't, we just call the
6383 core C<readline()> and return its value.
6389 # Localize to prevent it from being smashed in the program being debugged.
6392 # Pull a line out of the typeahead if there's stuff there.
6395 # How many lines left.
6396 my $left = @typeahead;
6398 # Get the next line.
6399 my $got = shift @typeahead;
6401 # Print a message saying we got input from the typeahead.
6403 print $OUT "auto(-$left)", shift, $got, "\n";
6405 # Add it to the terminal history (if possible).
6406 $term->AddHistory($got)
6408 and defined $term->Features->{addHistory};
6410 } ## end if (@typeahead)
6412 # We really need to read some input. Turn off entry/exit trace and
6413 # return value printing.
6417 # If there are stacked filehandles to read from ...
6420 # Read from the last one in the stack.
6421 my $line = CORE::readline( $cmdfhs[-1] );
6423 # If we got a line ...
6425 ? ( print $OUT ">> $line" and return $line ) # Echo and return
6426 : close pop @cmdfhs; # Pop and close
6427 } ## end while (@cmdfhs)
6429 # Nothing on the filehandle stack. Socket?
6430 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
6432 # Send anyting we have to send.
6433 $OUT->write( join( '', @_ ) );
6435 # Receive anything there is to receive.
6440 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
6441 # XXX Don't know. You tell me.
6442 } while length $buf and ($stuff .= $buf) !~ /\n/;
6446 } ## end if (ref $OUT and UNIVERSAL::isa...
6448 # No socket. Just read from the terminal.
6450 $term->readline(@_);
6452 } ## end sub readline
6454 =head1 OPTIONS SUPPORT ROUTINES
6456 These routines handle listing and setting option values.
6458 =head2 C<dump_option> - list the current value of an option setting
6460 This routine uses C<option_val> to look up the value for an option.
6461 It cleans up escaped single-quotes and then displays the option and
6467 my ( $opt, $val ) = @_;
6468 $val = option_val( $opt, 'N/A' );
6469 $val =~ s/([\\\'])/\\$1/g;
6470 printf $OUT "%20s = '%s'\n", $opt, $val;
6471 } ## end sub dump_option
6473 sub options2remember {
6474 foreach my $k (@RememberOnROptions) {
6475 $option{$k} = option_val( $k, 'N/A' );
6480 =head2 C<option_val> - find the current value of an option
6482 This can't just be a simple hash lookup because of the indirect way that
6483 the option values are stored. Some are retrieved by calling a subroutine,
6484 some are just variables.
6486 You must supply a default value to be used in case the option isn't set.
6491 my ( $opt, $default ) = @_;
6494 # Does this option exist, and is it a variable?
6495 # If so, retrieve the value via the value in %optionVars.
6496 if ( defined $optionVars{$opt}
6497 and defined ${ $optionVars{$opt} } )
6499 $val = ${ $optionVars{$opt} };
6502 # Does this option exist, and it's a subroutine?
6503 # If so, call the subroutine via the ref in %optionAction
6504 # and capture the value.
6505 elsif ( defined $optionAction{$opt}
6506 and defined &{ $optionAction{$opt} } )
6508 $val = &{ $optionAction{$opt} }();
6511 # If there's an action or variable for the supplied option,
6512 # but no value was set, use the default.
6513 elsif (defined $optionAction{$opt} and not defined $option{$opt}
6514 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
6519 # Otherwise, do the simple hash lookup.
6521 $val = $option{$opt};
6524 # If the value isn't defined, use the default.
6525 # Then return whatever the value is.
6526 $val = $default unless defined $val;
6528 } ## end sub option_val
6530 =head2 C<parse_options>
6532 Handles the parsing and execution of option setting/displaying commands.
6534 An option entered by itself is assumed to be I<set me to 1> (the default value)
6535 if the option is a boolean one. If not, the user is prompted to enter a valid
6536 value or to query the current value (via C<option? >).
6538 If C<option=value> is entered, we try to extract a quoted string from the
6539 value (if it is quoted). If it's not, we just use the whole value as-is.
6541 We load any modules required to service this option, and then we set it: if
6542 it just gets stuck in a variable, we do that; if there's a subroutine to
6543 handle setting the option, we call that.
6545 Finally, if we're running in interactive mode, we display the effect of the
6546 user's command back to the terminal, skipping this if we're setting things
6547 during initialization.
6555 # These options need a value. Don't allow them to be clobbered by accident.
6556 my %opt_needs_val = map { ( $_ => 1 ) } qw{
6557 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
6558 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
6564 # Clean off excess leading whitespace.
6567 # Options are always all word characters, followed by a non-word
6569 s/^(\w+)(\W?)// or print( $OUT "Invalid option `$_'\n" ), last;
6570 my ( $opt, $sep ) = ( $1, $2 );
6572 # Make sure that such an option exists.
6573 my $matches = grep( /^\Q$opt/ && ( $option = $_ ), @options )
6574 || grep( /^\Q$opt/i && ( $option = $_ ), @options );
6576 print( $OUT "Unknown option `$opt'\n" ), next unless $matches;
6577 print( $OUT "Ambiguous option `$opt'\n" ), next if $matches > 1;
6580 # '?' as separator means query, but must have whitespace after it.
6581 if ( "?" eq $sep ) {
6582 print( $OUT "Option query `$opt?' followed by non-space `$_'\n" ),
6586 #&dump_option($opt);
6587 } ## end if ("?" eq $sep)
6589 # Separator is whitespace (or just a carriage return).
6590 # They're going for a default, which we assume is 1.
6591 elsif ( $sep !~ /\S/ ) {
6593 $val = "1"; # this is an evil default; make 'em set it!
6596 # Separator is =. Trying to set a value.
6597 elsif ( $sep eq "=" ) {
6599 # If quoted, extract a quoted string.
6600 if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
6602 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
6605 # Not quoted. Use the whole thing. Warn about 'option='.
6609 print OUT qq(Option better cleared using $opt=""\n)
6611 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
6613 } ## end elsif ($sep eq "=")
6615 # "Quoted" with [], <>, or {}.
6616 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
6618 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
6619 s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
6620 or print( $OUT "Unclosed option value `$opt$sep$_'\n" ), last;
6621 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
6622 } ## end else [ if ("?" eq $sep)
6624 # Exclude non-booleans from getting set to 1 by default.
6625 if ( $opt_needs_val{$option} && $val_defaulted ) {
6626 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
6628 "Option `$opt' is non-boolean. Use `$cmd $option=VAL' to set, `$cmd $option?' to query\n";
6630 } ## end if ($opt_needs_val{$option...
6632 # Save the option value.
6633 $option{$option} = $val if defined $val;
6635 # Load any module that this option requires.
6639 require '$optionRequire{$option}';
6641 } || die # XXX: shouldn't happen
6642 if defined $optionRequire{$option}
6646 # Stick it in the proper variable if it goes in a variable.
6647 ${ $optionVars{$option} } = $val
6648 if defined $optionVars{$option}
6651 # Call the appropriate sub if it gets set via sub.
6652 &{ $optionAction{$option} }($val)
6653 if defined $optionAction{$option}
6654 && defined &{ $optionAction{$option} }
6657 # Not initialization - echo the value we set it to.
6658 dump_option($option) unless $OUT eq \*STDERR;
6659 } ## end while (length)
6660 } ## end sub parse_options
6662 =head1 RESTART SUPPORT
6664 These routines are used to store (and restore) lists of items in environment
6665 variables during a restart.
6669 Set_list packages up items to be stored in a set of environment variables
6670 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
6671 the values). Values outside the standard ASCII charset are stored by encoding
6672 then as hexadecimal values.
6677 my ( $stem, @list ) = @_;
6680 # VAR_n: how many we have. Scalar assignment gets the number of items.
6681 $ENV{"${stem}_n"} = @list;
6683 # Grab each item in the list, escape the backslashes, encode the non-ASCII
6684 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
6685 for $i ( 0 .. $#list ) {
6687 $val =~ s/\\/\\\\/g;
6688 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
6689 $ENV{"${stem}_$i"} = $val;
6690 } ## end for $i (0 .. $#list)
6691 } ## end sub set_list
6695 Reverse the set_list operation: grab VAR_n to see how many we should be getting
6696 back, and then pull VAR_0, VAR_1. etc. back out.
6703 my $n = delete $ENV{"${stem}_n"};
6705 for $i ( 0 .. $n - 1 ) {
6706 $val = delete $ENV{"${stem}_$i"};
6707 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
6711 } ## end sub get_list
6713 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
6717 The C<catch()> subroutine is the essence of fast and low-impact. We simply
6718 set an already-existing global scalar variable to a constant value. This
6719 avoids allocating any memory possibly in the middle of something that will
6720 get all confused if we do, particularly under I<unsafe signals>.
6726 return; # Put nothing on the stack - malloc/free land!
6731 C<warn> emits a warning, by joining together its arguments and printing
6732 them, with couple of fillips.
6734 If the composited message I<doesn't> end with a newline, we automatically
6735 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
6736 to be set to the filehandle to be used to output warnings; it makes no
6737 assumptions about what filehandles are available.
6742 my ($msg) = join( "", @_ );
6743 $msg .= ": $!\n" unless $msg =~ /\n$/;
6748 =head1 INITIALIZATION TTY SUPPORT
6750 =head2 C<reset_IN_OUT>
6752 This routine handles restoring the debugger's input and output filehandles
6753 after we've tried and failed to move them elsewhere. In addition, it assigns
6754 the debugger's output filehandle to $LINEINFO if it was already open there.
6759 my $switch_li = $LINEINFO eq $OUT;
6761 # If there's a term and it's able to get a new tty, try to get one.
6762 if ( $term and $term->Features->{newTTY} ) {
6763 ( $IN, $OUT ) = ( shift, shift );
6764 $term->newTTY( $IN, $OUT );
6767 # This term can't get a new tty now. Better luck later.
6769 &warn("Too late to set IN/OUT filehandles, enabled on next `R'!\n");
6772 # Set the filehndles up as they were.
6774 ( $IN, $OUT ) = ( shift, shift );
6777 # Unbuffer the output filehandle.
6778 my $o = select $OUT;
6782 # Point LINEINFO to the same output filehandle if it was there before.
6783 $LINEINFO = $OUT if $switch_li;
6784 } ## end sub reset_IN_OUT
6786 =head1 OPTION SUPPORT ROUTINES
6788 The following routines are used to process some of the more complicated
6793 Sets the input and output filehandles to the specified files or pipes.
6794 If the terminal supports switching, we go ahead and do it. If not, and
6795 there's already a terminal in place, we save the information to take effect
6798 If there's no terminal yet (for instance, during debugger initialization),
6799 we go ahead and set C<$console> and C<$tty> to the file indicated.
6805 # With VMS we can get here with $term undefined, so we do not
6806 # switch to this terminal. There may be a better place to make
6807 # sure that $term is defined on VMS
6808 if ( @_ and ($^O eq 'VMS') and !defined($term) ) {
6809 eval { require Term::ReadLine } or die $@;
6811 $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT;
6814 $term = new Term::ReadLine 'perldb', $IN, $OUT;
6817 if ( @_ and $term and $term->Features->{newTTY} ) {
6819 # This terminal supports switching to a new TTY.
6820 # Can be a list of two files, or on string containing both names,
6822 # XXX Should this perhaps be an assignment from @_?
6823 my ( $in, $out ) = shift;
6826 # Split list apart if supplied.
6827 ( $in, $out ) = split /,/, $in, 2;
6831 # Use the same file for both input and output.
6835 # Open file onto the debugger's filehandles, if you can.
6836 open IN, $in or die "cannot open `$in' for read: $!";
6837 open OUT, ">$out" or die "cannot open `$out' for write: $!";
6839 # Swap to the new filehandles.
6840 reset_IN_OUT( \*IN, \*OUT );
6842 # Save the setting for later.
6844 } ## end if (@_ and $term and $term...
6846 # Terminal doesn't support new TTY, or doesn't support readline.
6847 # Can't do it now, try restarting.
6848 &warn("Too late to set TTY, enabled on next `R'!\n") if $term and @_;
6850 # Useful if done through PERLDB_OPTS:
6851 $console = $tty = shift if @_;
6853 # Return whatever the TTY is.
6859 Sets the C<$notty> global, controlling whether or not the debugger tries to
6860 get a terminal to read from. If called after a terminal is already in place,
6861 we save the value to use it if we're restarted.
6867 &warn("Too late to set noTTY, enabled on next `R'!\n") if @_;
6869 $notty = shift if @_;
6875 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
6876 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
6877 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
6878 the value in case a restart is done so we can change it then.
6884 &warn("Too late to set ReadLine, enabled on next `R'!\n") if @_;
6888 } ## end sub ReadLine
6890 =head2 C<RemotePort>
6892 Sets the port that the debugger will try to connect to when starting up.
6893 If the terminal's already been set up, we can't do it, but we remember the
6894 setting in case the user does a restart.
6900 &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
6902 $remoteport = shift if @_;
6904 } ## end sub RemotePort
6908 Checks with the terminal to see if C<Tk> is running, and returns true or
6909 false. Returns false if the current terminal doesn't support C<readline>.
6914 if ( ${ $term->Features }{tkRunning} ) {
6915 return $term->tkRunning(@_);
6919 print $OUT "tkRunning not supported by current ReadLine package.\n";
6922 } ## end sub tkRunning
6926 Sets nonstop mode. If a terminal's already been set up, it's too late; the
6927 debugger remembers the setting in case you restart, though.
6933 &warn("Too late to set up NonStop mode, enabled on next `R'!\n")
6936 $runnonstop = shift if @_;
6938 } ## end sub NonStop
6942 &warn("Some flag changes could not take effect until next 'R'!\n")
6945 $^P = parse_DollarCaretP_flags(shift) if @_;
6946 expand_DollarCaretP_flags($^P);
6949 sub OnlyAssertions {
6951 &warn("Too late to set up OnlyAssertions mode, enabled on next 'R'!\n")
6955 unless ( defined $ini_assertion ) {
6957 &warn("Current Perl interpreter doesn't support assertions");
6962 unless ($ini_assertion) {
6963 print "Assertions will be active on next 'R'!\n";
6966 $^P &= ~$DollarCaretP_flags{PERLDBf_SUB};
6967 $^P |= $DollarCaretP_flags{PERLDBf_ASSERTION};
6970 $^P |= $DollarCaretP_flags{PERLDBf_SUB};
6973 !( $^P & $DollarCaretP_flags{PERLDBf_SUB} ) || 0;
6978 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
6986 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
6993 Sets the shell escape command, and generates a printable copy to be used
7000 # If we got an argument, meta-quote it, and add '\b' if it
7001 # ends in a word character.
7003 $sh = quotemeta shift;
7004 $sh .= "\\b" if $sh =~ /\w$/;
7007 # Generate the printable version for the help:
7008 $psh = $sh; # copy it
7009 $psh =~ s/\\b$//; # Take off trailing \b if any
7010 $psh =~ s/\\(.)/$1/g; # De-escape
7011 $psh; # return the printable version
7012 } ## end sub shellBang
7016 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7017 was passed as the argument. (This means you can't override the terminal's
7023 if ( defined $term ) {
7025 # We don't want to show warning backtraces, but we do want die() ones.
7026 local ( $warnLevel, $dieLevel ) = ( 0, 1 );
7028 # No ornaments if the terminal doesn't support them.
7029 return '' unless $term->Features->{ornaments};
7030 eval { $term->ornaments(@_) } || '';
7033 # Use what was passed in if we can't determine it ourselves.
7037 } ## end sub ornaments
7039 =head2 C<recallCommand>
7041 Sets the recall command, and builds a printable version which will appear in
7048 # If there is input, metaquote it. Add '\b' if it ends with a word
7051 $rc = quotemeta shift;
7052 $rc .= "\\b" if $rc =~ /\w$/;
7055 # Build it into a printable version.
7056 $prc = $rc; # Copy it
7057 $prc =~ s/\\b$//; # Remove trailing \b
7058 $prc =~ s/\\(.)/$1/g; # Remove escapes
7059 $prc; # Return the printable version
7060 } ## end sub recallCommand
7062 =head2 C<LineInfo> - where the line number information goes
7064 Called with no arguments, returns the file or pipe that line info should go to.
7066 Called with an argument (a file or a pipe), it opens that onto the
7067 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7068 file or pipe again to the caller.
7073 return $lineinfo unless @_;
7076 # If this is a valid "thing to be opened for output", tack a
7077 # '>' onto the front.
7078 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7080 # If this is a pipe, the stream points to a slave editor.
7081 $slave_editor = ( $stream =~ /^\|/ );
7083 # Open it up and unbuffer it.
7084 open( LINEINFO, "$stream" ) || &warn("Cannot open `$stream' for write");
7085 $LINEINFO = \*LINEINFO;
7086 my $save = select($LINEINFO);
7090 # Hand the file or pipe back again.
7092 } ## end sub LineInfo
7094 =head1 COMMAND SUPPORT ROUTINES
7096 These subroutines provide functionality for various commands.
7098 =head2 C<list_modules>
7100 For the C<M> command: list modules loaded and their versions.
7101 Essentially just runs through the keys in %INC, picks each package's
7102 C<$VERSION> variable, gets the file name, and formats the information
7107 sub list_modules { # versions
7111 # keys are the "as-loaded" name, values are the fully-qualified path
7112 # to the file itself.
7114 $file = $_; # get the module name
7115 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7116 s,/,::,g; # change '/' to '::'
7117 s/^perl5db$/DB/; # Special case: debugger
7118 # moves to package DB
7119 s/^Term::ReadLine::readline$/readline/; # simplify readline
7121 # If the package has a $VERSION package global (as all good packages
7122 # should!) decode it and save as partial message.
7123 if ( defined ${ $_ . '::VERSION' } ) {
7124 $version{$file} = "${ $_ . '::VERSION' } from ";
7127 # Finish up the message with the file the package came from.
7128 $version{$file} .= $INC{$file};
7129 } ## end for (keys %INC)
7131 # Hey, dumpit() formats a hash nicely, so why not use it?
7132 dumpit( $OUT, \%version );
7133 } ## end sub list_modules
7137 Sets up the monster string used to format and print the help.
7139 =head3 HELP MESSAGE FORMAT
7141 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
7142 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
7143 easy to parse and portable, but which still allows the help to be a little
7144 nicer than just plain text.
7146 Essentially, you define the command name (usually marked up with C<< B<> >>
7147 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
7148 newline. The descriptive text can also be marked up in the same way. If you
7149 need to continue the descriptive text to another line, start that line with
7150 just tabs and then enter the marked-up text.
7152 If you are modifying the help text, I<be careful>. The help-string parser is
7153 not very sophisticated, and if you don't follow these rules it will mangle the
7154 help beyond hope until you fix the string.
7160 # XXX: make sure there are tabs between the command and explanation,
7161 # or print_help will screw up your formatting if you have
7162 # eeevil ornaments enabled. This is an insane mess.
7165 Help is currently only available for the new 5.8 command set.
7166 No help is available for the old command set.
7167 We assume you know what you're doing if you switch to it.
7170 B<s> [I<expr>] Single step [in I<expr>].
7171 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7172 <B<CR>> Repeat last B<n> or B<s> command.
7173 B<r> Return from current subroutine.
7174 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7175 at the specified position.
7176 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7177 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7178 B<l> I<line> List single I<line>.
7179 B<l> I<subname> List first window of lines from subroutine.
7180 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7181 B<l> List next window of lines.
7182 B<-> List previous window of lines.
7183 B<v> [I<line>] View window around I<line>.
7184 B<.> Return to the executed line.
7185 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7186 I<filename> may be either the full name of the file, or a regular
7187 expression matching the full file name:
7188 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7189 Evals (with saved bodies) are considered to be filenames:
7190 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7191 (in the order of execution).
7192 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7193 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7194 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
7195 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7196 B<t> Toggle trace mode.
7197 B<t> I<expr> Trace through execution of I<expr>.
7198 B<b> Sets breakpoint on current line)
7199 B<b> [I<line>] [I<condition>]
7200 Set breakpoint; I<line> defaults to the current execution line;
7201 I<condition> breaks if it evaluates to true, defaults to '1'.
7202 B<b> I<subname> [I<condition>]
7203 Set breakpoint at first line of subroutine.
7204 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7205 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7206 B<b> B<postpone> I<subname> [I<condition>]
7207 Set breakpoint at first line of subroutine after
7209 B<b> B<compile> I<subname>
7210 Stop after the subroutine is compiled.
7211 B<B> [I<line>] Delete the breakpoint for I<line>.
7212 B<B> I<*> Delete all breakpoints.
7213 B<a> [I<line>] I<command>
7214 Set an action to be done before the I<line> is executed;
7215 I<line> defaults to the current execution line.
7216 Sequence is: check for breakpoint/watchpoint, print line
7217 if necessary, do action, prompt user if necessary,
7220 B<A> [I<line>] Delete the action for I<line>.
7221 B<A> I<*> Delete all actions.
7222 B<w> I<expr> Add a global watch-expression.
7224 B<W> I<expr> Delete a global watch-expression.
7225 B<W> I<*> Delete all watch-expressions.
7226 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7227 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7228 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7229 B<x> I<expr> Evals expression in list context, dumps the result.
7230 B<m> I<expr> Evals expression in list context, prints methods callable
7231 on the first element of the result.
7232 B<m> I<class> Prints methods callable via the given class.
7233 B<M> Show versions of loaded modules.
7234 B<i> I<class> Prints nested parents of given class.
7235 B<e> Display current thread id.
7236 B<E> Display all thread ids the current one will be identified: <n>.
7237 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7238 B<P> Something to do with assertions...
7240 B<<> ? List Perl commands to run before each prompt.
7241 B<<> I<expr> Define Perl command to run before each prompt.
7242 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7243 B<< *> Delete the list of perl commands to run before each prompt.
7244 B<>> ? List Perl commands to run after each prompt.
7245 B<>> I<expr> Define Perl command to run after each prompt.
7246 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7247 B<>>B< *> Delete the list of Perl commands to run after each prompt.
7248 B<{> I<db_command> Define debugger command to run before each prompt.
7249 B<{> ? List debugger commands to run before each prompt.
7250 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7251 B<{ *> Delete the list of debugger commands to run before each prompt.
7252 B<$prc> I<number> Redo a previous command (default previous command).
7253 B<$prc> I<-number> Redo number'th-to-last command.
7254 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7255 See 'B<O> I<recallCommand>' too.
7256 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7261 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7263 See 'B<O> I<shellBang>' too.
7264 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7265 B<save> I<file> Save current debugger session (actual history) to I<file>.
7266 B<rerun> Rerun session to current position.
7267 B<rerun> I<n> Rerun session to numbered command.
7268 B<rerun> I<-n> Rerun session to number'th-to-last command.
7269 B<H> I<-number> Display last number commands (default all).
7270 B<H> I<*> Delete complete history.
7271 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7272 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7273 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7274 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7275 I<command> Execute as a perl statement in current package.
7276 B<R> Pure-man-restart of debugger, some of debugger state
7277 and command-line options may be lost.
7278 Currently the following settings are preserved:
7279 history, breakpoints and actions, debugger B<O>ptions
7280 and the following command-line options: I<-w>, I<-I>, I<-e>.
7282 B<o> [I<opt>] ... Set boolean option to true
7283 B<o> [I<opt>B<?>] Query options
7284 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7285 Set options. Use quotes if spaces in value.
7286 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7287 I<pager> program for output of \"|cmd\";
7288 I<tkRunning> run Tk while prompting (with ReadLine);
7289 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7290 I<inhibit_exit> Allows stepping off the end of the script.
7291 I<ImmediateStop> Debugger should stop as early as possible.
7292 I<RemotePort> Remote hostname:port for remote debugging
7293 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7294 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7295 I<compactDump>, I<veryCompact> change style of array and hash dump;
7296 I<globPrint> whether to print contents of globs;
7297 I<DumpDBFiles> dump arrays holding debugged files;
7298 I<DumpPackages> dump symbol tables of packages;
7299 I<DumpReused> dump contents of \"reused\" addresses;
7300 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7301 I<bareStringify> Do not print the overload-stringified value;
7302 Other options include:
7303 I<PrintRet> affects printing of return value after B<r> command,
7304 I<frame> affects printing messages on subroutine entry/exit.
7305 I<AutoTrace> affects printing messages on possible breaking points.
7306 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7307 I<ornaments> affects screen appearance of the command line.
7308 I<CreateTTY> bits control attempts to create a new TTY on events:
7309 1: on fork() 2: debugger is started inside debugger
7311 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7312 You can put additional initialization options I<TTY>, I<noTTY>,
7313 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7314 `B<R>' after you set them).
7316 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7317 B<h> Summary of debugger commands.
7318 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7319 B<h h> Long help for debugger commands
7320 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7321 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7322 Set B<\$DB::doccmd> to change viewer.
7324 Type `|h h' for a paged display if this was too hard to read.
7326 "; # Fix balance of vi % matching: }}}}
7328 # note: tabs in the following section are not-so-helpful
7329 $summary = <<"END_SUM";
7330 I<List/search source lines:> I<Control script execution:>
7331 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7332 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7333 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7334 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7335 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7336 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7337 I<Debugger controls:> B<L> List break/watch/actions
7338 B<o> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7339 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7340 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7341 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7342 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7343 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7344 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7345 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7346 B<q> or B<^D> Quit B<R> Attempt a restart
7347 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7348 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7349 B<p> I<expr> Print expression (uses script's current package).
7350 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7351 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7352 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
7353 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7354 B<e> Display thread id B<E> Display all thread ids.
7355 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7358 # ')}}; # Fix balance of vi % matching
7360 # and this is really numb...
7363 B<s> [I<expr>] Single step [in I<expr>].
7364 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7365 B<CR>> Repeat last B<n> or B<s> command.
7366 B<r> Return from current subroutine.
7367 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7368 at the specified position.
7369 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7370 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7371 B<l> I<line> List single I<line>.
7372 B<l> I<subname> List first window of lines from subroutine.
7373 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7374 B<l> List next window of lines.
7375 B<-> List previous window of lines.
7376 B<w> [I<line>] List window around I<line>.
7377 B<.> Return to the executed line.
7378 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7379 I<filename> may be either the full name of the file, or a regular
7380 expression matching the full file name:
7381 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7382 Evals (with saved bodies) are considered to be filenames:
7383 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7384 (in the order of execution).
7385 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7386 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7387 B<L> List all breakpoints and actions.
7388 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7389 B<t> Toggle trace mode.
7390 B<t> I<expr> Trace through execution of I<expr>.
7391 B<b> [I<line>] [I<condition>]
7392 Set breakpoint; I<line> defaults to the current execution line;
7393 I<condition> breaks if it evaluates to true, defaults to '1'.
7394 B<b> I<subname> [I<condition>]
7395 Set breakpoint at first line of subroutine.
7396 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7397 B<b> B<load> I<filename> Set breakpoint on `require'ing the given file.
7398 B<b> B<postpone> I<subname> [I<condition>]
7399 Set breakpoint at first line of subroutine after
7401 B<b> B<compile> I<subname>
7402 Stop after the subroutine is compiled.
7403 B<d> [I<line>] Delete the breakpoint for I<line>.
7404 B<D> Delete all breakpoints.
7405 B<a> [I<line>] I<command>
7406 Set an action to be done before the I<line> is executed;
7407 I<line> defaults to the current execution line.
7408 Sequence is: check for breakpoint/watchpoint, print line
7409 if necessary, do action, prompt user if necessary,
7411 B<a> [I<line>] Delete the action for I<line>.
7412 B<A> Delete all actions.
7413 B<W> I<expr> Add a global watch-expression.
7414 B<W> Delete all watch-expressions.
7415 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7416 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7417 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7418 B<x> I<expr> Evals expression in list context, dumps the result.
7419 B<m> I<expr> Evals expression in list context, prints methods callable
7420 on the first element of the result.
7421 B<m> I<class> Prints methods callable via the given class.
7423 B<<> ? List Perl commands to run before each prompt.
7424 B<<> I<expr> Define Perl command to run before each prompt.
7425 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7426 B<>> ? List Perl commands to run after each prompt.
7427 B<>> I<expr> Define Perl command to run after each prompt.
7428 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7429 B<{> I<db_command> Define debugger command to run before each prompt.
7430 B<{> ? List debugger commands to run before each prompt.
7431 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7432 B<$prc> I<number> Redo a previous command (default previous command).
7433 B<$prc> I<-number> Redo number'th-to-last command.
7434 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7435 See 'B<O> I<recallCommand>' too.
7436 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7441 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7443 See 'B<O> I<shellBang>' too.
7444 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7445 B<H> I<-number> Display last number commands (default all).
7446 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7447 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7448 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7449 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7450 I<command> Execute as a perl statement in current package.
7451 B<v> Show versions of loaded modules.
7452 B<R> Pure-man-restart of debugger, some of debugger state
7453 and command-line options may be lost.
7454 Currently the following settings are preserved:
7455 history, breakpoints and actions, debugger B<O>ptions
7456 and the following command-line options: I<-w>, I<-I>, I<-e>.
7458 B<O> [I<opt>] ... Set boolean option to true
7459 B<O> [I<opt>B<?>] Query options
7460 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7461 Set options. Use quotes if spaces in value.
7462 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7463 I<pager> program for output of \"|cmd\";
7464 I<tkRunning> run Tk while prompting (with ReadLine);
7465 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7466 I<inhibit_exit> Allows stepping off the end of the script.
7467 I<ImmediateStop> Debugger should stop as early as possible.
7468 I<RemotePort> Remote hostname:port for remote debugging
7469 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7470 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7471 I<compactDump>, I<veryCompact> change style of array and hash dump;
7472 I<globPrint> whether to print contents of globs;
7473 I<DumpDBFiles> dump arrays holding debugged files;
7474 I<DumpPackages> dump symbol tables of packages;
7475 I<DumpReused> dump contents of \"reused\" addresses;
7476 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7477 I<bareStringify> Do not print the overload-stringified value;
7478 Other options include:
7479 I<PrintRet> affects printing of return value after B<r> command,
7480 I<frame> affects printing messages on subroutine entry/exit.
7481 I<AutoTrace> affects printing messages on possible breaking points.
7482 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7483 I<ornaments> affects screen appearance of the command line.
7484 I<CreateTTY> bits control attempts to create a new TTY on events:
7485 1: on fork() 2: debugger is started inside debugger
7487 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7488 You can put additional initialization options I<TTY>, I<noTTY>,
7489 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7490 `B<R>' after you set them).
7492 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7493 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7494 B<h h> Summary of debugger commands.
7495 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7496 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7497 Set B<\$DB::doccmd> to change viewer.
7499 Type `|h' for a paged display if this was too hard to read.
7501 "; # Fix balance of vi % matching: }}}}
7503 # note: tabs in the following section are not-so-helpful
7504 $pre580_summary = <<"END_SUM";
7505 I<List/search source lines:> I<Control script execution:>
7506 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7507 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7508 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
7509 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7510 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7511 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
7512 I<Debugger controls:> B<L> List break/watch/actions
7513 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7514 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7515 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
7516 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7517 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
7518 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
7519 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7520 B<q> or B<^D> Quit B<R> Attempt a restart
7521 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7522 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7523 B<p> I<expr> Print expression (uses script's current package).
7524 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7525 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7526 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
7527 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7528 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7531 # ')}}; # Fix balance of vi % matching
7533 } ## end sub sethelp
7535 =head2 C<print_help()>
7537 Most of what C<print_help> does is just text formatting. It finds the
7538 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
7539 terminal control characters to simulate them (courtesy of
7540 C<Term::ReadLine::TermCap>).
7547 # Restore proper alignment destroyed by eeevil I<> and B<>
7548 # ornaments: A pox on both their houses!
7550 # A help command will have everything up to and including
7551 # the first tab sequence padded into a field 16 (or if indented 20)
7552 # wide. If it's wider than that, an extra space will be added.
7554 ^ # only matters at start of line
7555 ( \040{4} | \t )* # some subcommands are indented
7556 ( < ? # so <CR> works
7557 [BI] < [^\t\n] + ) # find an eeevil ornament
7558 ( \t+ ) # original separation, discarded
7559 ( .* ) # this will now start (no earlier) than
7562 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
7563 my $clean = $command;
7564 $clean =~ s/[BI]<([^>]*)>/$1/g;
7566 # replace with this whole string:
7567 ($leadwhite ? " " x 4 : "")
7569 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
7574 s{ # handle bold ornaments
7575 B < ( [^>] + | > ) >
7577 $Term::ReadLine::TermCap::rl_term_set[2]
7579 . $Term::ReadLine::TermCap::rl_term_set[3]
7582 s{ # handle italic ornaments
7583 I < ( [^>] + | > ) >
7585 $Term::ReadLine::TermCap::rl_term_set[0]
7587 . $Term::ReadLine::TermCap::rl_term_set[1]
7592 } ## end sub print_help
7596 This routine does a lot of gyrations to be sure that the pager is C<less>.
7597 It checks for C<less> masquerading as C<more> and records the result in
7598 C<$ENV{LESS}> so we don't have to go through doing the stats again.
7604 # We already know if this is set.
7605 return if defined $ENV{LESS} && $ENV{LESS} =~ /r/;
7607 # Pager is less for sure.
7608 my $is_less = $pager =~ /\bless\b/;
7609 if ( $pager =~ /\bmore\b/ ) {
7611 # Nope, set to more. See what's out there.
7612 my @st_more = stat('/usr/bin/more');
7613 my @st_less = stat('/usr/bin/less');
7615 # is it really less, pretending to be more?
7618 && $st_more[0] == $st_less[0]
7619 && $st_more[1] == $st_less[1];
7620 } ## end if ($pager =~ /\bmore\b/)
7622 # changes environment!
7623 # 'r' added so we don't do (slow) stats again.
7624 $ENV{LESS} .= 'r' if $is_less;
7625 } ## end sub fix_less
7627 =head1 DIE AND WARN MANAGEMENT
7631 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
7632 to debug a debugger problem.
7634 It does its best to report the error that occurred, and then forces the
7635 program, debugger, and everything to die.
7641 # No entry/exit messages.
7644 # No return value prints.
7647 # set the abort signal handling to the default (just terminate).
7648 $SIG{'ABRT'} = 'DEFAULT';
7650 # If we enter the signal handler recursively, kill myself with an
7651 # abort signal (so we just terminate).
7652 kill 'ABRT', $$ if $panic++;
7654 # If we can show detailed info, do so.
7655 if ( defined &Carp::longmess ) {
7657 # Don't recursively enter the warn handler, since we're carping.
7658 local $SIG{__WARN__} = '';
7660 # Skip two levels before reporting traceback: we're skipping
7661 # mydie and confess.
7662 local $Carp::CarpLevel = 2; # mydie + confess
7664 # Tell us all about it.
7665 &warn( Carp::longmess("Signal @_") );
7668 # No Carp. Tell us about the signal as best we can.
7671 print $DB::OUT "Got signal @_\n";
7676 } ## end sub diesignal
7680 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
7681 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
7687 # No entry/exit trace.
7690 # No return value printing.
7693 # Turn off warn and die handling to prevent recursive entries to this
7695 local $SIG{__WARN__} = '';
7696 local $SIG{__DIE__} = '';
7698 # Load Carp if we can. If $^S is false (current thing being compiled isn't
7699 # done yet), we may not be able to do a require.
7700 eval { require Carp }
7701 if defined $^S; # If error/warning during compilation,
7702 # require may be broken.
7704 # Use the core warn() unless Carp loaded OK.
7706 "\nCannot print stack trace, load with -MCarp option to see stack" ),
7708 unless defined &Carp::longmess;
7710 # Save the current values of $single and $trace, and then turn them off.
7711 my ( $mysingle, $mytrace ) = ( $single, $trace );
7715 # We can call Carp::longmess without its being "debugged" (which we
7716 # don't want - we just want to use it!). Capture this for later.
7717 my $mess = Carp::longmess(@_);
7719 # Restore $single and $trace to their original values.
7720 ( $single, $trace ) = ( $mysingle, $mytrace );
7722 # Use the debugger's own special way of printing warnings to print
7723 # the stack trace message.
7729 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
7730 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
7731 single stepping and tracing during the call to C<Carp::longmess> to avoid
7732 debugging it - we just want to use it.
7734 If C<dieLevel> is zero, we let the program being debugged handle the
7735 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
7736 the debugger takes over all exception handling, printing a backtrace and
7737 displaying the exception via its C<dbwarn()> routine.
7744 local $SIG{__DIE__} = '';
7745 local $SIG{__WARN__} = '';
7749 if ( $dieLevel > 2 ) {
7750 local $SIG{__WARN__} = \&dbwarn;
7751 &warn(@_); # Yell no matter what
7754 if ( $dieLevel < 2 ) {
7755 die @_ if $^S; # in eval propagate
7758 # The code used to check $^S to see if compiliation of the current thing
7759 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
7760 eval { require Carp };
7763 "\nCannot print stack trace, load with -MCarp option to see stack" )
7764 unless defined &Carp::longmess;
7766 # We do not want to debug this chunk (automatic disabling works
7767 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
7768 # get the stack trace from Carp::longmess (if possible), restore $signal
7769 # and $trace, and then die with the stack trace.
7770 my ( $mysingle, $mytrace ) = ( $single, $trace );
7776 package Carp; # Do not include us in the list
7777 eval { $mess = Carp::longmess(@_); };
7779 ( $single, $trace ) = ( $mysingle, $mytrace );
7783 =head2 C<warnlevel()>
7785 Set the C<$DB::warnLevel> variable that stores the value of the
7786 C<warnLevel> option. Calling C<warnLevel()> with a positive value
7787 results in the debugger taking over all warning handlers. Setting
7788 C<warnLevel> to zero leaves any warning handlers set up by the program
7789 being debugged in place.
7795 $prevwarn = $SIG{__WARN__} unless $warnLevel;
7798 $SIG{__WARN__} = \&DB::dbwarn;
7801 $SIG{__WARN__} = $prevwarn;
7805 } ## end sub warnLevel
7809 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
7810 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
7811 zero lets you use your own C<die()> handler.
7818 $prevdie = $SIG{__DIE__} unless $dieLevel;
7822 # Always set it to dbdie() for non-zero values.
7823 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
7825 # No longer exists, so don't try to use it.
7826 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
7828 # If we've finished initialization, mention that stack dumps
7829 # are enabled, If dieLevel is 1, we won't stack dump if we die
7831 print $OUT "Stack dump during die enabled",
7832 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
7835 # XXX This is probably obsolete, given that diehard() is gone.
7836 print $OUT "Dump printed too.\n" if $dieLevel > 2;
7837 } ## end if ($dieLevel)
7839 # Put the old one back if there was one.
7841 $SIG{__DIE__} = $prevdie;
7842 print $OUT "Default die handler restored.\n";
7846 } ## end sub dieLevel
7848 =head2 C<signalLevel>
7850 Number three in a series: set C<signalLevel> to zero to keep your own
7851 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
7852 takes over and handles them with C<DB::diesignal()>.
7858 $prevsegv = $SIG{SEGV} unless $signalLevel;
7859 $prevbus = $SIG{BUS} unless $signalLevel;
7860 $signalLevel = shift;
7862 $SIG{SEGV} = \&DB::diesignal;
7863 $SIG{BUS} = \&DB::diesignal;
7866 $SIG{SEGV} = $prevsegv;
7867 $SIG{BUS} = $prevbus;
7871 } ## end sub signalLevel
7873 =head1 SUBROUTINE DECODING SUPPORT
7875 These subroutines are used during the C<x> and C<X> commands to try to
7876 produce as much information as possible about a code reference. They use
7877 L<Devel::Peek> to try to find the glob in which this code reference lives
7878 (if it does) - this allows us to actually code references which correspond
7879 to named subroutines (including those aliased via glob assignment).
7881 =head2 C<CvGV_name()>
7883 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
7884 via that routine. If this fails, return the reference again (when the
7885 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
7891 my $name = CvGV_name_or_bust($in);
7892 defined $name ? $name : $in;
7895 =head2 C<CvGV_name_or_bust> I<coderef>
7897 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
7898 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
7899 find a glob for this ref.
7901 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
7905 sub CvGV_name_or_bust {
7907 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
7908 return unless ref $in;
7909 $in = \&$in; # Hard reference...
7910 eval { require Devel::Peek; 1 } or return;
7911 my $gv = Devel::Peek::CvGV($in) or return;
7912 *$gv{PACKAGE} . '::' . *$gv{NAME};
7913 } ## end sub CvGV_name_or_bust
7917 A utility routine used in various places; finds the file where a subroutine
7918 was defined, and returns that filename and a line-number range.
7920 Tries to use C<@sub> first; if it can't find it there, it tries building a
7921 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
7922 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
7923 this way, it brute-force searches C<%sub>, checking for identical references.
7930 return unless defined &$subr;
7931 my $name = CvGV_name_or_bust($subr);
7933 $data = $sub{$name} if defined $name;
7934 return $data if defined $data;
7937 $subr = \&$subr; # Hard reference
7940 $s = $_, last if $subr eq \&$_;
7944 } ## end sub find_sub
7948 A subroutine that uses the utility function C<methods_via> to find all the
7949 methods in the class corresponding to the current reference and in
7956 # Figure out the class - either this is the class or it's a reference
7957 # to something blessed into that class.
7959 $class = ref $class if ref $class;
7963 # Show the methods that this class has.
7964 methods_via( $class, '', 1 );
7966 # Show the methods that UNIVERSAL has.
7967 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
7968 } ## end sub methods
7970 =head2 C<methods_via($class, $prefix, $crawl_upward)>
7972 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
7973 all the parent class methods. C<$class> is the name of the next class to
7974 try; C<$prefix> is the message prefix, which gets built up as we go up the
7975 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
7976 higher in the C<@ISA> tree, 0 if we should stop.
7982 # If we've processed this class already, just quit.
7984 return if $seen{$class}++;
7986 # This is a package that is contributing the methods we're about to print.
7988 my $prepend = $prefix ? "via $prefix: " : '';
7993 # Keep if this is a defined subroutine in this class.
7994 grep { defined &{ ${"${class}::"}{$_} } }
7996 # Extract from all the symbols in this class.
7997 sort keys %{"${class}::"}
8001 # If we printed this already, skip it.
8002 next if $seen{$name}++;
8004 # Print the new method name.
8007 print $DB::OUT "$prepend$name\n";
8008 } ## end for $name (grep { defined...
8010 # If the $crawl_upward argument is false, just quit here.
8011 return unless shift;
8013 # $crawl_upward true: keep going up the tree.
8014 # Find all the classes this one is a subclass of.
8015 for $name ( @{"${class}::ISA"} ) {
8017 # Set up the new prefix.
8018 $prepend = $prefix ? $prefix . " -> $name" : $name;
8020 # Crawl up the tree and keep trying to crawl up.
8021 methods_via( $name, $prepend, 1 );
8023 } ## end sub methods_via
8025 =head2 C<setman> - figure out which command to use to show documentation
8027 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8032 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|MacOS|NetWare)\z/s
8033 ? "man" # O Happy Day!
8034 : "perldoc"; # Alas, poor unfortunates
8037 =head2 C<runman> - run the appropriate command to show documentation
8039 Accepts a man page name; runs the appropriate command to display it (set up
8040 during debugger initialization). Uses C<DB::system> to avoid mucking up the
8041 program's STDIN and STDOUT.
8048 &system("$doccmd $doccmd");
8052 # this way user can override, like with $doccmd="man -Mwhatever"
8053 # or even just "man " to disable the path check.
8054 unless ( $doccmd eq 'man' ) {
8055 &system("$doccmd $page");
8059 $page = 'perl' if lc($page) eq 'help';
8062 my $man1dir = $Config::Config{'man1dir'};
8063 my $man3dir = $Config::Config{'man3dir'};
8064 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8066 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8067 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8068 chop $manpath if $manpath;
8070 # harmless if missing, I figure
8071 my $oldpath = $ENV{MANPATH};
8072 $ENV{MANPATH} = $manpath if $manpath;
8073 my $nopathopt = $^O =~ /dunno what goes here/;
8078 # I just *know* there are men without -M
8079 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8084 unless ( $page =~ /^perl\w/ ) {
8085 # do it this way because its easier to slurp in to keep up to date - clunky though.
8224 if (grep { $page eq $_ } @pods) {
8226 CORE::system( $doccmd,
8227 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8229 } ## end if (grep { $page eq $_...
8230 } ## end unless ($page =~ /^perl\w/)
8231 } ## end if (CORE::system($doccmd...
8232 if ( defined $oldpath ) {
8233 $ENV{MANPATH} = $manpath;
8236 delete $ENV{MANPATH};
8240 #use Carp; # This did break, left for debugging
8242 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
8244 Because of the way the debugger interface to the Perl core is designed, any
8245 debugger package globals that C<DB::sub()> requires have to be defined before
8246 any subroutines can be called. These are defined in the second C<BEGIN> block.
8248 This block sets things up so that (basically) the world is sane
8249 before the debugger starts executing. We set up various variables that the
8250 debugger has to have set up before the Perl core starts running:
8256 The debugger's own filehandles (copies of STD and STDOUT for now).
8260 Characters for shell escapes, the recall command, and the history command.
8264 The maximum recursion depth.
8268 The size of a C<w> command's window.
8272 The before-this-line context to be printed in a C<v> (view a window around this line) command.
8276 The fact that we're not in a sub at all right now.
8280 The default SIGINT handler for the debugger.
8284 The appropriate value of the flag in C<$^D> that says the debugger is running
8288 The current debugger recursion level
8292 The list of postponed items and the C<$single> stack (XXX define this)
8296 That we want no return values and no subroutine entry/exit trace.
8302 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
8304 BEGIN { # This does not compile, alas. (XXX eh?)
8305 $IN = \*STDIN; # For bugs before DB::OUT has been opened
8306 $OUT = \*STDERR; # For errors before DB::OUT has been opened
8308 # Define characters used by command parsing.
8309 $sh = '!'; # Shell escape (does not work)
8310 $rc = ','; # Recall command (does not work)
8311 @hist = ('?'); # Show history (does not work)
8312 @truehist = (); # Can be saved for replay (per session)
8314 # This defines the point at which you get the 'deep recursion'
8315 # warning. It MUST be defined or the debugger will not load.
8318 # Number of lines around the current one that are shown in the
8322 # How much before-the-current-line context the 'v' command should
8323 # use in calculating the start of the window it will display.
8326 # We're not in any sub yet, but we need this to be a defined value.
8329 # Set up the debugger's interrupt handler. It simply sets a flag
8330 # ($signal) that DB::DB() will check before each command is executed.
8331 $SIG{INT} = \&DB::catch;
8333 # The following lines supposedly, if uncommented, allow the debugger to
8334 # debug itself. Perhaps we can try that someday.
8335 # This may be enabled to debug debugger:
8336 #$warnLevel = 1 unless defined $warnLevel;
8337 #$dieLevel = 1 unless defined $dieLevel;
8338 #$signalLevel = 1 unless defined $signalLevel;
8340 # This is the flag that says "a debugger is running, please call
8341 # DB::DB and DB::sub". We will turn it on forcibly before we try to
8342 # execute anything in the user's context, because we always want to
8344 $db_stop = 0; # Compiler warning ...
8345 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
8347 # This variable records how many levels we're nested in debugging. Used
8348 # Used in the debugger prompt, and in determining whether it's all over or
8350 $level = 0; # Level of recursive debugging
8352 # "Triggers bug (?) in perl if we postpone this until runtime."
8353 # XXX No details on this yet, or whether we should fix the bug instead
8354 # of work around it. Stay tuned.
8355 @postponed = @stack = (0);
8357 # Used to track the current stack depth using the auto-stacked-variable
8359 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
8361 # Don't print return values on exiting a subroutine.
8364 # No extry/exit tracing.
8369 BEGIN { $^W = $ini_warn; } # Switch warnings back
8371 =head1 READLINE SUPPORT - COMPLETION FUNCTION
8375 C<readline> support - adds command completion to basic C<readline>.
8377 Returns a list of possible completions to C<readline> when invoked. C<readline>
8378 will print the longest common substring following the text already entered.
8380 If there is only a single possible completion, C<readline> will use it in full.
8382 This code uses C<map> and C<grep> heavily to create lists of possible
8383 completion. Think LISP in this section.
8389 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
8390 # $text is the text to be completed.
8391 # $line is the incoming line typed by the user.
8392 # $start is the start of the text to be completed in the incoming line.
8393 my ( $text, $line, $start ) = @_;
8395 # Save the initial text.
8396 # The search pattern is current package, ::, extract the next qualifier
8397 # Prefix and pack are set to undef.
8398 my ( $itext, $search, $prefix, $pack ) =
8399 ( $text, "^\Q${'package'}::\E([^:]+)\$" );
8401 =head3 C<b postpone|compile>
8407 Find all the subroutines that might match in this package
8411 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
8415 Include all the rest of the subs that are known
8419 C<grep> out the ones that match the text we have so far
8423 Return this as the list of possible completions
8429 return sort grep /^\Q$text/, ( keys %sub ),
8430 qw(postpone load compile), # subroutines
8431 ( map { /$search/ ? ($1) : () } keys %sub )
8432 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
8436 Get all the possible files from C<@INC> as it currently stands and
8437 select the ones that match the text so far.
8441 return sort grep /^\Q$text/, values %INC # files
8442 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
8444 =head3 C<V> (list variable) and C<m> (list modules)
8446 There are two entry points for these commands:
8448 =head4 Unqualified package names
8450 Get the top-level packages and grab everything that matches the text
8451 so far. For each match, recursively complete the partial packages to
8452 get all possible matching packages. Return this sorted list.
8456 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8457 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
8458 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
8460 =head4 Qualified package names
8462 Take a partially-qualified package and find all subpackages for it
8463 by getting all the subpackages for the package so far, matching all
8464 the subpackages against the text, and discarding all of them which
8465 start with 'main::'. Return this list.
8469 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8470 grep !/^main::/, grep /^\Q$text/,
8471 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () } keys %{ $prefix . '::' }
8472 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
8473 and $text =~ /^(.*[^:])::?(\w*)$/
8476 =head3 C<f> - switch files
8478 Here, we want to get a fully-qualified filename for the C<f> command.
8483 =item 1. The original source file itself
8485 =item 2. A file from C<@INC>
8487 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
8493 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
8494 # We might possibly want to switch to an eval (which has a "filename"
8495 # like '(eval 9)'), so we may need to clean up the completion text
8496 # before proceeding.
8497 $prefix = length($1) - length($text);
8502 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
8503 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
8504 out of C<%main::>, add the initial source file, and extract the ones that
8505 match the completion text so far.
8510 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
8512 } ## end if ($line =~ /^\|*f\s+(.*)/)
8514 =head3 Subroutine name completion
8516 We look through all of the defined subs (the keys of C<%sub>) and
8517 return both all the possible matches to the subroutine name plus
8518 all the matches qualified to the current package.
8522 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
8523 $text = substr $text, 1;
8525 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
8527 map { /$search/ ? ($1) : () }
8530 } ## end if ((substr $text, 0, ...
8532 =head3 Scalar, array, and hash completion: partially qualified package
8534 Much like the above, except we have to do a little more cleanup:
8538 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
8546 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
8550 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
8556 Figure out the prefix vs. what needs completing.
8560 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
8567 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
8571 my @out = map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
8578 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.
8582 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8583 return db_complete( $out[0], $line, $start );
8586 # Return the list of possibles.
8589 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
8595 =head3 Symbol completion: current package or package C<main>.
8599 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
8607 If it's C<main>, delete main to just get C<::> leading.
8611 $pack = ( $package eq 'main' ? '' : $package ) . '::';
8617 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
8621 $prefix = substr $text, 0, 1;
8622 $text = substr $text, 1;
8628 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
8632 my @out = map "$prefix$_", grep /^\Q$text/,
8633 ( grep /^_?[a-zA-Z]/, keys %$pack ),
8634 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
8638 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
8644 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8645 return db_complete( $out[0], $line, $start );
8648 # Return the list of possibles.
8650 } ## end if ($text =~ /^[\$@%]/)
8654 We use C<option_val()> to look up the current value of the option. If there's
8655 only a single value, we complete the command in such a way that it is a
8656 complete command for setting the option in question. If there are multiple
8657 possible values, we generate a command consisting of the option plus a trailing
8658 question mark, which, if executed, will list the current value of the option.
8662 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
8663 { # Options after space
8664 # We look for the text to be matched in the list of possible options,
8665 # and fetch the current value.
8666 my @out = grep /^\Q$text/, @options;
8667 my $val = option_val( $out[0], undef );
8669 # Set up a 'query option's value' command.
8671 if ( not defined $val or $val =~ /[\n\r]/ ) {
8673 # There's really nothing else we can do.
8676 # We have a value. Create a proper option-setting command.
8677 elsif ( $val =~ /\s/ ) {
8679 # XXX This may be an extraneous variable.
8682 # We'll want to quote the string (because of the embedded
8683 # whtespace), but we want to make sure we don't end up with
8684 # mismatched quote characters. We try several possibilities.
8685 foreach $l ( split //, qq/\"\'\#\|/ ) {
8687 # If we didn't find this quote character in the value,
8688 # quote it using this quote character.
8689 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
8691 } ## end elsif ($val =~ /\s/)
8693 # Don't need any quotes.
8698 # If there were multiple possible values, return '? ', which
8699 # makes the command into a query command. If there was just one,
8700 # have readline append that.
8701 $rl_attribs->{completer_terminator_character} =
8702 ( @out == 1 ? $out : '? ' );
8704 # Return list of possibilities.
8706 } ## end if ((substr $line, 0, ...
8708 =head3 Filename completion
8710 For entering filenames. We simply call C<readline>'s C<filename_list()>
8711 method with the completion text to get the possible completions.
8715 return $term->filename_list($text); # filenames
8717 } ## end sub db_complete
8719 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
8721 Functions that possibly ought to be somewhere else.
8731 print $OUT "Use `q' to quit or `R' to restart. `h q' for details.\n";
8736 If we have $ini_pids, save it in the environment; else remove it from the
8737 environment. Used by the C<R> (restart) command.
8742 if ( defined($ini_pids) ) {
8743 $ENV{PERLDB_PIDS} = $ini_pids;
8746 delete( $ENV{PERLDB_PIDS} );
8748 } ## end sub clean_ENV
8750 # PERLDBf_... flag names from perl.h
8751 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
8754 %DollarCaretP_flags = (
8755 PERLDBf_SUB => 0x01, # Debug sub enter/exit
8756 PERLDBf_LINE => 0x02, # Keep line #
8757 PERLDBf_NOOPT => 0x04, # Switch off optimizations
8758 PERLDBf_INTER => 0x08, # Preserve more data
8759 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
8760 PERLDBf_SINGLE => 0x20, # Start with single-step on
8761 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
8762 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
8763 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
8764 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
8765 PERLDBf_ASSERTION => 0x400, # Debug assertion subs enter/exit
8766 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO, _ASSERTION
8769 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
8772 sub parse_DollarCaretP_flags {
8777 foreach my $f ( split /\s*\|\s*/, $flags ) {
8779 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
8782 elsif ( $f =~ /^(\d+)$/ ) {
8785 elsif ( $f =~ /^DEFAULT$/i ) {
8786 $value = $DollarCaretP_flags{PERLDB_ALL};
8789 $f =~ /^(?:PERLDBf_)?(.*)$/i;
8790 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
8791 unless ( defined $value ) {
8793 "Unrecognized \$^P flag '$f'!\n",
8794 "Acceptable flags are: "
8795 . join( ', ', sort keys %DollarCaretP_flags ),
8796 ", and hexadecimal and decimal numbers.\n"
8806 sub expand_DollarCaretP_flags {
8807 my $DollarCaretP = shift;
8810 my $n = ( 1 << $_ );
8811 ( $DollarCaretP & $n )
8812 ? ( $DollarCaretP_flags_r{$n}
8813 || sprintf( '0x%x', $n ) )
8817 return @bits ? join( '|', @bits ) : 0;
8824 Rerun the current session to:
8826 rerun current position
8828 rerun 4 command number 4
8830 rerun -4 current command minus 4 (go back 4 steps)
8832 Whether this always makes sense, in the current context is unknowable, and is
8833 in part left as a useful exersize for the reader. This sub returns the
8834 appropriate arguments to rerun the current session.
8841 pop(@truehist); # strim
8842 unless (defined $truehist[$i]) {
8843 print "Unable to return to non-existent command: $i\n";
8845 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
8846 my @temp = @truehist; # store
8847 push(@DB::typeahead, @truehist); # saved
8848 @truehist = @hist = (); # flush
8849 @args = &restart(); # setup
8850 &get_list("PERLDB_HIST"); # clean
8851 &set_list("PERLDB_HIST", @temp); # reset
8858 Restarting the debugger is a complex operation that occurs in several phases.
8859 First, we try to reconstruct the command line that was used to invoke Perl
8865 # I may not be able to resurrect you, but here goes ...
8867 "Warning: some settings and command-line options may be lost!\n";
8868 my ( @script, @flags, $cl );
8870 # If warn was on before, turn it on again.
8871 push @flags, '-w' if $ini_warn;
8872 if ( $ini_assertion and @{^ASSERTING} ) {
8874 ( map { /\:\^\(\?\:(.*)\)\$\)/ ? "-A$1" : "-A$_" }
8878 # Rebuild the -I flags that were on the initial
8881 push @flags, '-I', $_;
8884 # Turn on taint if it was on before.
8885 push @flags, '-T' if ${^TAINT};
8887 # Arrange for setting the old INC:
8888 # Save the current @init_INC in the environment.
8889 set_list( "PERLDB_INC", @ini_INC );
8891 # If this was a perl one-liner, go to the "file"
8892 # corresponding to the one-liner read all the lines
8893 # out of it (except for the first one, which is going
8894 # to be added back on again when 'perl -d' runs: that's
8895 # the 'require perl5db.pl;' line), and add them back on
8896 # to the command line to be executed.
8898 for ( 1 .. $#{'::_<-e'} ) { # The first line is PERL5DB
8899 chomp( $cl = ${'::_<-e'}[$_] );
8900 push @script, '-e', $cl;
8902 } ## end if ($0 eq '-e')
8904 # Otherwise we just reuse the original name we had
8912 After the command line has been reconstructed, the next step is to save
8913 the debugger's status in environment variables. The C<DB::set_list> routine
8914 is used to save aggregate variables (both hashes and arrays); scalars are
8915 just popped into environment variables directly.
8919 # If the terminal supported history, grab it and
8920 # save that in the environment.
8921 set_list( "PERLDB_HIST",
8922 $term->Features->{getHistory}
8926 # Find all the files that were visited during this
8927 # session (i.e., the debugger had magic hashes
8928 # corresponding to them) and stick them in the environment.
8929 my @had_breakpoints = keys %had_breakpoints;
8930 set_list( "PERLDB_VISITED", @had_breakpoints );
8932 # Save the debugger options we chose.
8933 set_list( "PERLDB_OPT", %option );
8934 # set_list( "PERLDB_OPT", options2remember() );
8936 # Save the break-on-loads.
8937 set_list( "PERLDB_ON_LOAD", %break_on_load );
8941 The most complex part of this is the saving of all of the breakpoints. They
8942 can live in an awful lot of places, and we have to go through all of them,
8943 find the breakpoints, and then save them in the appropriate environment
8944 variable via C<DB::set_list>.
8948 # Go through all the breakpoints and make sure they're
8951 for ( 0 .. $#had_breakpoints ) {
8953 # We were in this file.
8954 my $file = $had_breakpoints[$_];
8956 # Grab that file's magic line hash.
8957 *dbline = $main::{ '_<' . $file };
8959 # Skip out if it doesn't exist, or if the breakpoint
8960 # is in a postponed file (we'll do postponed ones
8962 next unless %dbline or $postponed_file{$file};
8964 # In an eval. This is a little harder, so we'll
8965 # do more processing on that below.
8966 ( push @hard, $file ), next
8967 if $file =~ /^\(\w*eval/;
8969 # XXX I have no idea what this is doing. Yet.
8971 @add = %{ $postponed_file{$file} }
8972 if $postponed_file{$file};
8974 # Save the list of all the breakpoints for this file.
8975 set_list( "PERLDB_FILE_$_", %dbline, @add );
8976 } ## end for (0 .. $#had_breakpoints)
8978 # The breakpoint was inside an eval. This is a little
8979 # more difficult. XXX and I don't understand it.
8981 # Get over to the eval in question.
8982 *dbline = $main::{ '_<' . $_ };
8983 my ( $quoted, $sub, %subs, $line ) = quotemeta $_;
8984 for $sub ( keys %sub ) {
8985 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
8986 $subs{$sub} = [ $1, $2 ];
8990 "No subroutines in $_, ignoring breakpoints.\n";
8993 LINES: for $line ( keys %dbline ) {
8995 # One breakpoint per sub only:
8996 my ( $offset, $sub, $found );
8997 SUBS: for $sub ( keys %subs ) {
9000 $line # Not after the subroutine
9002 not defined $offset # Not caught
9008 $offset = $line - $subs{$sub}->[0];
9009 $offset = "+$offset", last SUBS
9011 } ## end if ($subs{$sub}->[1] >=...
9012 } ## end for $sub (keys %subs)
9013 if ( defined $offset ) {
9014 $postponed{$found} =
9015 "break $offset if $dbline{$line}";
9019 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
9021 } ## end for $line (keys %dbline)
9022 } ## end for (@hard)
9024 # Save the other things that don't need to be
9026 set_list( "PERLDB_POSTPONE", %postponed );
9027 set_list( "PERLDB_PRETYPE", @$pretype );
9028 set_list( "PERLDB_PRE", @$pre );
9029 set_list( "PERLDB_POST", @$post );
9030 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9032 # We are oficially restarting.
9033 $ENV{PERLDB_RESTART} = 1;
9035 # We are junking all child debuggers.
9036 delete $ENV{PERLDB_PIDS}; # Restore ini state
9038 # Set this back to the initial pid.
9039 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9043 After all the debugger status has been saved, we take the command we built up
9044 and then return it, so we can C<exec()> it. The debugger will spot the
9045 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9046 from the environment.
9050 # And run Perl again. Add the "-d" flag, all the
9051 # flags we built up, the script (whether a one-liner
9052 # or a file), add on the -emacs flag for a slave editor,
9053 # and then the old arguments.
9055 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9061 =head1 END PROCESSING - THE C<END> BLOCK
9063 Come here at the very end of processing. We want to go into a
9064 loop where we allow the user to enter commands and interact with the
9065 debugger, but we don't want anything else to execute.
9067 First we set the C<$finished> variable, so that some commands that
9068 shouldn't be run after the end of program quit working.
9070 We then figure out whether we're truly done (as in the user entered a C<q>
9071 command, or we finished execution while running nonstop). If we aren't,
9072 we set C<$single> to 1 (causing the debugger to get control again).
9074 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9075 message and returns control to the debugger. Repeat.
9077 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9078 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9079 break, run to completion.).
9084 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9085 $fall_off_end = 1 unless $inhibit_exit;
9087 # Do not stop in at_exit() and destructors on exit:
9088 if ($fall_off_end or $runnonstop) {
9092 DB::fake::at_exit();
9096 =head1 PRE-5.8 COMMANDS
9098 Some of the commands changed function quite a bit in the 5.8 command
9099 realignment, so much so that the old code had to be replaced completely.
9100 Because we wanted to retain the option of being able to go back to the
9101 former command set, we moved the old code off to this section.
9103 There's an awful lot of duplicated code here. We've duplicated the
9104 comments to keep things clear.
9108 Does nothing. Used to I<turn off> commands.
9112 sub cmd_pre580_null {
9117 =head2 Old C<a> command.
9119 This version added actions if you supplied them, and deleted them
9128 # Argument supplied. Add the action.
9129 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9131 # If the line isn't there, use the current line.
9135 # If there is an action ...
9138 # ... but the line isn't breakable, skip it.
9139 if ( $dbline[$i] == 0 ) {
9140 print $OUT "Line $i may not have an action.\n";
9144 # ... and the line is breakable:
9145 # Mark that there's an action in this file.
9146 $had_breakpoints{$filename} |= 2;
9148 # Delete any current action.
9149 $dbline{$i} =~ s/\0[^\0]*//;
9151 # Add the new action, continuing the line as needed.
9152 $dbline{$i} .= "\0" . action($j);
9154 } ## end if (length $j)
9156 # No action supplied.
9159 # Delete the action.
9160 $dbline{$i} =~ s/\0[^\0]*//;
9162 # Mark as having no break or action if nothing's left.
9163 delete $dbline{$i} if $dbline{$i} eq '';
9165 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9166 } ## end sub cmd_pre580_a
9168 =head2 Old C<b> command
9180 if ( $cmd =~ /^load\b\s*(.*)/ ) {
9186 # b compile|postpone <some sub> [<condition>]
9187 # The interpreter actually traps this one for us; we just put the
9188 # necessary condition in the %postponed hash.
9189 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
9191 # Capture the condition if there is one. Make it true if none.
9192 my $cond = length $3 ? $3 : '1';
9194 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
9195 # if it was 'compile'.
9196 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
9198 # De-Perl4-ify the name - ' separators to ::.
9199 $subname =~ s/\'/::/g;
9201 # Qualify it into the current package unless it's already qualified.
9202 $subname = "${'package'}::" . $subname
9203 unless $subname =~ /::/;
9205 # Add main if it starts with ::.
9206 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
9208 # Save the break type for this sub.
9209 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
9210 } ## end elsif ($cmd =~ ...
9212 # b <sub name> [<condition>]
9213 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
9215 my $cond = length $2 ? $2 : '1';
9216 &cmd_b_sub( $subname, $cond );
9219 # b <line> [<condition>].
9220 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9221 my $i = $1 || $dbline;
9222 my $cond = length $2 ? $2 : '1';
9223 &cmd_b_line( $i, $cond );
9225 } ## end sub cmd_pre580_b
9227 =head2 Old C<D> command.
9229 Delete all breakpoints unconditionally.
9236 if ( $cmd =~ /^\s*$/ ) {
9237 print $OUT "Deleting all breakpoints...\n";
9239 # %had_breakpoints lists every file that had at least one
9242 for $file ( keys %had_breakpoints ) {
9244 # Switch to the desired file temporarily.
9245 local *dbline = $main::{ '_<' . $file };
9250 # For all lines in this file ...
9251 for ( $i = 1 ; $i <= $max ; $i++ ) {
9253 # If there's a breakpoint or action on this line ...
9254 if ( defined $dbline{$i} ) {
9256 # ... remove the breakpoint.
9257 $dbline{$i} =~ s/^[^\0]+//;
9258 if ( $dbline{$i} =~ s/^\0?$// ) {
9260 # Remove the entry altogether if no action is there.
9263 } ## end if (defined $dbline{$i...
9264 } ## end for ($i = 1 ; $i <= $max...
9266 # If, after we turn off the "there were breakpoints in this file"
9267 # bit, the entry in %had_breakpoints for this file is zero,
9268 # we should remove this file from the hash.
9269 if ( not $had_breakpoints{$file} &= ~1 ) {
9270 delete $had_breakpoints{$file};
9272 } ## end for $file (keys %had_breakpoints)
9274 # Kill off all the other breakpoints that are waiting for files that
9275 # haven't been loaded yet.
9277 undef %postponed_file;
9278 undef %break_on_load;
9279 } ## end if ($cmd =~ /^\s*$/)
9280 } ## end sub cmd_pre580_D
9282 =head2 Old C<h> command
9284 Print help. Defaults to printing the long-form help; the 5.8 version
9285 prints the summary by default.
9293 # Print the *right* help, long format.
9294 if ( $cmd =~ /^\s*$/ ) {
9295 print_help($pre580_help);
9298 # 'h h' - explicitly-requested summary.
9299 elsif ( $cmd =~ /^h\s*/ ) {
9300 print_help($pre580_summary);
9303 # Find and print a command's help.
9304 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
9305 my $asked = $1; # for proper errmsg
9306 my $qasked = quotemeta($asked); # for searching
9307 # XXX: finds CR but not <CR>
9311 (?:[IB]<) # Optional markup
9312 $qasked # The command name
9319 ( # The command help:
9321 (?:[IB]<) # Optional markup
9322 $qasked # The command name
9323 ([\s\S]*?) # Lines starting with tabs
9327 ) # Line not starting with space
9328 # (Next command's help)
9332 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
9336 print_help("B<$asked> is not a debugger command.\n");
9338 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
9339 } ## end sub cmd_pre580_h
9341 =head2 Old C<W> command
9343 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
9351 # Delete all watch expressions.
9352 if ( $cmd =~ /^$/ ) {
9354 # No watching is going on.
9357 # Kill all the watch expressions and values.
9358 @to_watch = @old_watch = ();
9361 # Add a watch expression.
9362 elsif ( $cmd =~ /^(.*)/s ) {
9364 # add it to the list to be watched.
9367 # Get the current value of the expression.
9368 # Doesn't handle expressions returning list values!
9371 $val = ( defined $val ) ? "'$val'" : 'undef';
9374 push @old_watch, $val;
9376 # We're watching stuff.
9379 } ## end elsif ($cmd =~ /^(.*)/s)
9380 } ## end sub cmd_pre580_W
9382 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
9384 The debugger used to have a bunch of nearly-identical code to handle
9385 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
9386 C<cmd_prepost> unify all this into one set of code to handle the
9387 appropriate actions.
9389 =head2 C<cmd_pre590_prepost>
9391 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
9392 do something destructive. In pre 5.8 debuggers, the default action was to
9393 delete all the actions.
9397 sub cmd_pre590_prepost {
9399 my $line = shift || '*';
9402 return &cmd_prepost( $cmd, $line, $dbline );
9403 } ## end sub cmd_pre590_prepost
9405 =head2 C<cmd_prepost>
9407 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
9408 Since the lists of actions are all held in arrays that are pointed to by
9409 references anyway, all we have to do is pick the right array reference and
9410 then use generic code to all, delete, or list actions.
9417 # No action supplied defaults to 'list'.
9418 my $line = shift || '?';
9420 # Figure out what to put in the prompt.
9423 # Make sure we have some array or another to address later.
9424 # This means that if ssome reason the tests fail, we won't be
9425 # trying to stash actions or delete them from the wrong place.
9428 # < - Perl code to run before prompt.
9429 if ( $cmd =~ /^\</o ) {
9430 $which = 'pre-perl';
9434 # > - Perl code to run after prompt.
9435 elsif ( $cmd =~ /^\>/o ) {
9436 $which = 'post-perl';
9440 # { - first check for properly-balanced braces.
9441 elsif ( $cmd =~ /^\{/o ) {
9442 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
9444 "$cmd is now a debugger command\nuse `;$cmd' if you mean Perl code\n";
9447 # Properly balanced. Pre-prompt debugger actions.
9449 $which = 'pre-debugger';
9452 } ## end elsif ( $cmd =~ /^\{/o )
9454 # Did we find something that makes sense?
9456 print $OUT "Confused by command: $cmd\n";
9463 if ( $line =~ /^\s*\?\s*$/o ) {
9466 # Nothing there. Complain.
9467 print $OUT "No $which actions.\n";
9471 # List the actions in the selected list.
9472 print $OUT "$which commands:\n";
9473 foreach my $action (@$aref) {
9474 print $OUT "\t$cmd -- $action\n";
9477 } ## end if ( $line =~ /^\s*\?\s*$/o)
9479 # Might be a delete.
9481 if ( length($cmd) == 1 ) {
9482 if ( $line =~ /^\s*\*\s*$/o ) {
9484 # It's a delete. Get rid of the old actions in the
9487 print $OUT "All $cmd actions cleared.\n";
9491 # Replace all the actions. (This is a <, >, or {).
9492 @$aref = action($line);
9494 } ## end if ( length($cmd) == 1)
9495 elsif ( length($cmd) == 2 ) {
9497 # Add the action to the line. (This is a <<, >>, or {{).
9498 push @$aref, action($line);
9502 # <<<, >>>>, {{{{{{ ... something not a command.
9504 "Confused by strange length of $which command($cmd)...\n";
9506 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
9508 } ## end sub cmd_prepost
9512 Contains the C<at_exit> routine that the debugger uses to issue the
9513 C<Debugged program terminated ...> message after the program completes. See
9514 the C<END> block documentation for more details.
9521 "Debugged program terminated. Use `q' to quit or `R' to restart.";
9524 package DB; # Do not trace this 1; below!