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.
244 &parse_options("NonStop=1 LineInfo=db.out");
245 sub afterinit { $trace = 1; }
247 The script will run without human intervention, putting trace
248 information into C<db.out>. (If you interrupt it, you had better
249 reset C<LineInfo> to something I<interactive>!)
251 =head1 INTERNALS DESCRIPTION
253 =head2 DEBUGGER INTERFACE VARIABLES
255 Perl supplies the values for C<%sub>. It effectively inserts
256 a C<&DB::DB();> in front of each place that can have a
257 breakpoint. At each subroutine call, it calls C<&DB::sub> with
258 C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
259 {require 'perl5db.pl'}> before the first line.
261 After each C<require>d file is compiled, but before it is executed, a
262 call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
263 is the expanded name of the C<require>d file (as found via C<%INC>).
265 =head3 IMPORTANT INTERNAL VARIABLES
269 Used to control when the debugger will attempt to acquire another TTY to be
274 =item * 1 - on C<fork()>
276 =item * 2 - debugger is started inside debugger
278 =item * 4 - on startup
284 The value -2 indicates that no return value should be printed.
285 Any other positive value causes C<DB::sub> to print return values.
289 The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
290 contents of C<@_> when C<DB::eval> is called.
294 Determines what messages (if any) will get printed when a subroutine (or eval)
295 is entered or exited.
299 =item * 0 - No enter/exit messages
301 =item * 1 - Print I<entering> messages on subroutine entry
303 =item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
305 =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.
307 =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.
309 =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.
313 To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
314 The debugger internally juggles the value of C<$frame> during execution to
315 protect external modules that the debugger uses from getting traced.
319 Tracks current debugger nesting level. Used to figure out how many
320 C<E<lt>E<gt>> pairs to surround the line number with when the debugger
321 outputs a prompt. Also used to help determine if the program has finished
322 during command parsing.
324 =head4 C<$onetimeDump>
326 Controls what (if anything) C<DB::eval()> will print after evaluating an
331 =item * C<undef> - don't print anything
333 =item * C<dump> - use C<dumpvar.pl> to display the value returned
335 =item * C<methods> - print the methods callable on the first item returned
339 =head4 C<$onetimeDumpDepth>
341 Controls how far down C<dumpvar.pl> will go before printing C<...> while
342 dumping a structure. Numeric. If C<undef>, print all levels.
346 Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
347 which is called before every statement, checks this and puts the user into
348 command mode if it finds C<$signal> set to a true value.
352 Controls behavior during single-stepping. Stacked in C<@stack> on entry to
353 each subroutine; popped again at the end of each subroutine.
357 =item * 0 - run continuously.
359 =item * 1 - single-step, go into subs. The C<s> command.
361 =item * 2 - single-step, don't go into subs. The C<n> command.
363 =item * 4 - print current sub depth (turned on to force this when C<too much
370 Controls the output of trace information.
374 =item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
376 =item * 2 - watch expressions are active
378 =item * 4 - user defined a C<watchfunction()> in C<afterinit()>
382 =head4 C<$slave_editor>
384 1 if C<LINEINFO> was directed to a pipe; 0 otherwise.
388 Stack of filehandles that C<DB::readline()> will read commands from.
389 Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
393 Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
394 supplied by the Perl interpreter to the debugger. Contains the source.
398 Previous values of watch expressions. First set when the expression is
399 entered; reset whenever the watch expression changes.
403 Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
404 so that the debugger can substitute safe values while it's running, and
405 restore them when it returns control.
409 Saves the current value of C<$single> on entry to a subroutine.
410 Manipulated by the C<c> command to turn off tracing in all subs above the
415 The 'watch' expressions: to be evaluated before each line is executed.
419 The typeahead buffer, used by C<DB::readline>.
423 Command aliases. Stored as character strings to be substituted for a command
426 =head4 C<%break_on_load>
428 Keys are file names, values are 1 (break when this file is loaded) or undef
429 (don't break when it is loaded).
433 Keys are line numbers, values are C<condition\0action>. If used in numeric
434 context, values are 0 if not breakable, 1 if breakable, no matter what is
435 in the actual hash entry.
437 =head4 C<%had_breakpoints>
439 Keys are file names; values are bitfields:
443 =item * 1 - file has a breakpoint in it.
445 =item * 2 - file has an action in it.
449 A zero or undefined value means this file has neither.
453 Stores the debugger options. These are character string values.
457 Saves breakpoints for code that hasn't been compiled yet.
458 Keys are subroutine names, values are:
462 =item * C<compile> - break when this sub is compiled
464 =item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
468 =head4 C<%postponed_file>
470 This hash keeps track of breakpoints that need to be set for files that have
471 not yet been compiled. Keys are filenames; values are references to hashes.
472 Each of these hashes is keyed by line number, and its values are breakpoint
473 definitions (C<condition\0action>).
475 =head1 DEBUGGER INITIALIZATION
477 The debugger's initialization actually jumps all over the place inside this
478 package. This is because there are several BEGIN blocks (which of course
479 execute immediately) spread through the code. Why is that?
481 The debugger needs to be able to change some things and set some things up
482 before the debugger code is compiled; most notably, the C<$deep> variable that
483 C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
484 debugger has to turn off warnings while the debugger code is compiled, but then
485 restore them to their original setting before the program being debugged begins
488 The first C<BEGIN> block simply turns off warnings by saving the current
489 setting of C<$^W> and then setting it to zero. The second one initializes
490 the debugger variables that are needed before the debugger begins executing.
491 The third one puts C<$^X> back to its former value.
493 We'll detail the second C<BEGIN> block later; just remember that if you need
494 to initialize something before the debugger starts really executing, that's
501 BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
503 # Debugger for Perl 5.00x; perl5db.pl patch level:
506 $header = "perl5db.pl version $VERSION";
508 =head1 DEBUGGER ROUTINES
512 This function replaces straight C<eval()> inside the debugger; it simplifies
513 the process of evaluating code in the user's context.
515 The code to be evaluated is passed via the package global variable
516 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
518 Before we do the C<eval()>, we preserve the current settings of C<$trace>,
519 C<$single>, C<$^D> and C<$usercontext>. The latter contains the
520 preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
521 user's current package, grabbed when C<DB::DB> got control. This causes the
522 proper context to be used when the eval is actually done. Afterward, we
523 restore C<$trace>, C<$single>, and C<$^D>.
525 Next we need to handle C<$@> without getting confused. We save C<$@> in a
526 local lexical, localize C<$saved[0]> (which is where C<save()> will put
527 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
528 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
529 considered sane by the debugger. If there was an C<eval()> error, we print
530 it on the debugger's output. If C<$onetimedump> is defined, we call
531 C<dumpit> if it's set to 'dump', or C<methods> if it's set to
532 'methods'. Setting it to something else causes the debugger to do the eval
533 but not print the result - handy if you want to do something else with it
534 (the "watch expressions" code does this to get the value of the watch
535 expression but not show it unless it matters).
537 In any case, we then return the list of output from C<eval> to the caller,
538 and unwinding restores the former version of C<$@> in C<@saved> as well
539 (the localization of C<$saved[0]> goes away at the end of this scope).
541 =head3 Parameters and variables influencing execution of DB::eval()
543 C<DB::eval> isn't parameterized in the standard way; this is to keep the
544 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
545 The variables listed below influence C<DB::eval()>'s execution directly.
549 =item C<$evalarg> - the thing to actually be eval'ed
551 =item C<$trace> - Current state of execution tracing
553 =item C<$single> - Current state of single-stepping
555 =item C<$onetimeDump> - what is to be displayed after the evaluation
557 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
561 The following variables are altered by C<DB::eval()> during its execution. They
562 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
566 =item C<@res> - used to capture output from actual C<eval>.
568 =item C<$otrace> - saved value of C<$trace>.
570 =item C<$osingle> - saved value of C<$single>.
572 =item C<$od> - saved value of C<$^D>.
574 =item C<$saved[0]> - saved value of C<$@>.
576 =item $\ - for output of C<$@> if there is an evaluation error.
580 =head3 The problem of lexicals
582 The context of C<DB::eval()> presents us with some problems. Obviously,
583 we want to be 'sandboxed' away from the debugger's internals when we do
584 the eval, but we need some way to control how punctuation variables and
585 debugger globals are used.
587 We can't use local, because the code inside C<DB::eval> can see localized
588 variables; and we can't use C<my> either for the same reason. The code
589 in this routine compromises and uses C<my>.
591 After this routine is over, we don't have user code executing in the debugger's
592 context, so we can use C<my> freely.
596 ############################################## Begin lexical danger zone
598 # 'my' variables used here could leak into (that is, be visible in)
599 # the context that the code being evaluated is executing in. This means that
600 # the code could modify the debugger's variables.
602 # Fiddling with the debugger's context could be Bad. We insulate things as
607 # 'my' would make it visible from user code
608 # but so does local! --tchrist
609 # Remember: this localizes @DB::res, not @main::res.
613 # Try to keep the user code from messing with us. Save these so that
614 # even if the eval'ed code changes them, we can put them back again.
615 # Needed because the user could refer directly to the debugger's
616 # package globals (and any 'my' variables in this containing scope)
617 # inside the eval(), and we want to try to stay safe.
618 local $otrace = $trace;
619 local $osingle = $single;
622 # Untaint the incoming eval() argument.
623 { ($evalarg) = $evalarg =~ /(.*)/s; }
625 # $usercontext built in DB::DB near the comment
626 # "set up the context for DB::eval ..."
627 # Evaluate and save any results.
628 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
630 # Restore those old values.
636 # Save the current value of $@, and preserve it in the debugger's copy
637 # of the saved precious globals.
640 # Since we're only saving $@, we only have to localize the array element
641 # that it will be stored in.
642 local $saved[0]; # Preserve the old value of $@
645 # Now see whether we need to report an error back to the user.
651 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
652 # are package globals.
653 elsif ($onetimeDump) {
654 if ( $onetimeDump eq 'dump' ) {
655 local $option{dumpDepth} = $onetimedumpDepth
656 if defined $onetimedumpDepth;
657 dumpit( $OUT, \@res );
659 elsif ( $onetimeDump eq 'methods' ) {
662 } ## end elsif ($onetimeDump)
666 ############################################## End lexical danger zone
668 # After this point it is safe to introduce lexicals.
669 # The code being debugged will be executing in its own context, and
670 # can't see the inside of the debugger.
672 # However, one should not overdo it: leave as much control from outside as
673 # possible. If you make something a lexical, it's not going to be addressable
674 # from outside the debugger even if you know its name.
676 # This file is automatically included if you do perl -d.
677 # It's probably not useful to include this yourself.
679 # Before venturing further into these twisty passages, it is
680 # wise to read the perldebguts man page or risk the ire of dragons.
682 # (It should be noted that perldebguts will tell you a lot about
683 # the underlying mechanics of how the debugger interfaces into the
684 # Perl interpreter, but not a lot about the debugger itself. The new
685 # comments in this code try to address this problem.)
687 # Note that no subroutine call is possible until &DB::sub is defined
688 # (for subroutines defined outside of the package DB). In fact the same is
689 # true if $deep is not defined.
691 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
693 # modified Perl debugger, to be run from Emacs in perldb-mode
694 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
695 # Johan Vromans -- upgrade to 4.0 pl 10
696 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
698 # (We have made efforts to clarify the comments in the change log
699 # in other places; some of them may seem somewhat obscure as they
700 # were originally written, and explaining them away from the code
701 # in question seems conterproductive.. -JM)
703 ########################################################################
705 # + A lot of things changed after 0.94. First of all, core now informs
706 # debugger about entry into XSUBs, overloaded operators, tied operations,
707 # BEGIN and END. Handy with `O f=2'.
708 # + This can make debugger a little bit too verbose, please be patient
709 # and report your problems promptly.
710 # + Now the option frame has 3 values: 0,1,2. XXX Document!
711 # + Note that if DESTROY returns a reference to the object (or object),
712 # the deletion of data may be postponed until the next function call,
713 # due to the need to examine the return value.
716 # + `v' command shows versions.
719 # + `v' command shows version of readline.
720 # primitive completion works (dynamic variables, subs for `b' and `l',
721 # options). Can `p %var'
722 # + Better help (`h <' now works). New commands <<, >>, {, {{.
723 # {dump|print}_trace() coded (to be able to do it from <<cmd).
724 # + `c sub' documented.
725 # + At last enough magic combined to stop after the end of debuggee.
726 # + !! should work now (thanks to Emacs bracket matching an extra
727 # `]' in a regexp is caught).
728 # + `L', `D' and `A' span files now (as documented).
729 # + Breakpoints in `require'd code are possible (used in `R').
730 # + Some additional words on internal work of debugger.
731 # + `b load filename' implemented.
732 # + `b postpone subr' implemented.
733 # + now only `q' exits debugger (overwritable on $inhibit_exit).
734 # + When restarting debugger breakpoints/actions persist.
735 # + Buglet: When restarting debugger only one breakpoint/action per
736 # autoloaded function persists.
738 # Changes: 0.97: NonStop will not stop in at_exit().
739 # + Option AutoTrace implemented.
740 # + Trace printed differently if frames are printed too.
741 # + new `inhibitExit' option.
742 # + printing of a very long statement interruptible.
743 # Changes: 0.98: New command `m' for printing possible methods
744 # + 'l -' is a synonym for `-'.
745 # + Cosmetic bugs in printing stack trace.
746 # + `frame' & 8 to print "expanded args" in stack trace.
747 # + Can list/break in imported subs.
748 # + new `maxTraceLen' option.
749 # + frame & 4 and frame & 8 granted.
751 # + nonstoppable lines do not have `:' near the line number.
752 # + `b compile subname' implemented.
753 # + Will not use $` any more.
754 # + `-' behaves sane now.
755 # Changes: 0.99: Completion for `f', `m'.
756 # + `m' will remove duplicate names instead of duplicate functions.
757 # + `b load' strips trailing whitespace.
758 # completion ignores leading `|'; takes into account current package
759 # when completing a subroutine name (same for `l').
760 # Changes: 1.07: Many fixed by tchrist 13-March-2000
762 # + Added bare minimal security checks on perldb rc files, plus
763 # comments on what else is needed.
764 # + Fixed the ornaments that made "|h" completely unusable.
765 # They are not used in print_help if they will hurt. Strip pod
766 # if we're paging to less.
767 # + Fixed mis-formatting of help messages caused by ornaments
768 # to restore Larry's original formatting.
769 # + Fixed many other formatting errors. The code is still suboptimal,
770 # and needs a lot of work at restructuring. It's also misindented
772 # + Fixed bug where trying to look at an option like your pager
774 # + Fixed some $? processing. Note: if you use csh or tcsh, you will
775 # lose. You should consider shell escapes not using their shell,
776 # or else not caring about detailed status. This should really be
777 # unified into one place, too.
778 # + Fixed bug where invisible trailing whitespace on commands hoses you,
779 # tricking Perl into thinking you weren't calling a debugger command!
780 # + Fixed bug where leading whitespace on commands hoses you. (One
781 # suggests a leading semicolon or any other irrelevant non-whitespace
782 # to indicate literal Perl code.)
783 # + Fixed bugs that ate warnings due to wrong selected handle.
784 # + Fixed a precedence bug on signal stuff.
785 # + Fixed some unseemly wording.
786 # + Fixed bug in help command trying to call perl method code.
787 # + Fixed to call dumpvar from exception handler. SIGPIPE killed us.
789 # + Added some comments. This code is still nasty spaghetti.
790 # + Added message if you clear your pre/post command stacks which was
791 # very easy to do if you just typed a bare >, <, or {. (A command
792 # without an argument should *never* be a destructive action; this
793 # API is fundamentally screwed up; likewise option setting, which
794 # is equally buggered.)
795 # + Added command stack dump on argument of "?" for >, <, or {.
796 # + Added a semi-built-in doc viewer command that calls man with the
797 # proper %Config::Config path (and thus gets caching, man -k, etc),
798 # or else perldoc on obstreperous platforms.
799 # + Added to and rearranged the help information.
800 # + Detected apparent misuse of { ... } to declare a block; this used
801 # to work but now is a command, and mysteriously gave no complaint.
803 # Changes: 1.08: Apr 25, 2001 Jon Eveland <jweveland@yahoo.com>
805 # + This patch to perl5db.pl cleans up formatting issues on the help
806 # summary (h h) screen in the debugger. Mostly columnar alignment
807 # issues, plus converted the printed text to use all spaces, since
808 # tabs don't seem to help much here.
810 # Changes: 1.09: May 19, 2001 Ilya Zakharevich <ilya@math.ohio-state.edu>
811 # Minor bugs corrected;
812 # + Support for auto-creation of new TTY window on startup, either
813 # unconditionally, or if started as a kid of another debugger session;
814 # + New `O'ption CreateTTY
815 # I<CreateTTY> bits control attempts to create a new TTY on events:
817 # 2: debugger is started inside debugger
819 # + Code to auto-create a new TTY window on OS/2 (currently one
820 # extra window per session - need named pipes to have more...);
821 # + Simplified interface for custom createTTY functions (with a backward
822 # compatibility hack); now returns the TTY name to use; return of ''
823 # means that the function reset the I/O handles itself;
824 # + Better message on the semantic of custom createTTY function;
825 # + Convert the existing code to create a TTY into a custom createTTY
827 # + Consistent support for TTY names of the form "TTYin,TTYout";
828 # + Switch line-tracing output too to the created TTY window;
829 # + make `b fork' DWIM with CORE::GLOBAL::fork;
830 # + High-level debugger API cmd_*():
831 # cmd_b_load($filenamepart) # b load filenamepart
832 # cmd_b_line($lineno [, $cond]) # b lineno [cond]
833 # cmd_b_sub($sub [, $cond]) # b sub [cond]
834 # cmd_stop() # Control-C
835 # cmd_d($lineno) # d lineno (B)
836 # The cmd_*() API returns FALSE on failure; in this case it outputs
837 # the error message to the debugging output.
838 # + Low-level debugger API
839 # break_on_load($filename) # b load filename
840 # @files = report_break_on_load() # List files with load-breakpoints
841 # breakable_line_in_filename($name, $from [, $to])
842 # # First breakable line in the
843 # # range $from .. $to. $to defaults
844 # # to $from, and may be less than
846 # breakable_line($from [, $to]) # Same for the current file
847 # break_on_filename_line($name, $lineno [, $cond])
848 # # Set breakpoint,$cond defaults to
850 # break_on_filename_line_range($name, $from, $to [, $cond])
851 # # As above, on the first
852 # # breakable line in range
853 # break_on_line($lineno [, $cond]) # As above, in the current file
854 # break_subroutine($sub [, $cond]) # break on the first breakable line
855 # ($name, $from, $to) = subroutine_filename_lines($sub)
856 # # The range of lines of the text
857 # The low-level API returns TRUE on success, and die()s on failure.
859 # Changes: 1.10: May 23, 2001 Daniel Lewart <d-lewart@uiuc.edu>
861 # + Fixed warnings generated by "perl -dWe 42"
862 # + Corrected spelling errors
863 # + Squeezed Help (h) output into 80 columns
865 # Changes: 1.11: May 24, 2001 David Dyck <dcd@tc.fluke.com>
866 # + Made "x @INC" work like it used to
868 # Changes: 1.12: May 24, 2001 Daniel Lewart <d-lewart@uiuc.edu>
869 # + Fixed warnings generated by "O" (Show debugger options)
870 # + Fixed warnings generated by "p 42" (Print expression)
871 # Changes: 1.13: Jun 19, 2001 Scott.L.Miller@compaq.com
872 # + Added windowSize option
873 # Changes: 1.14: Oct 9, 2001 multiple
874 # + Clean up after itself on VMS (Charles Lane in 12385)
875 # + Adding "@ file" syntax (Peter Scott in 12014)
876 # + Debug reloading selfloaded stuff (Ilya Zakharevich in 11457)
877 # + $^S and other debugger fixes (Ilya Zakharevich in 11120)
878 # + Forgot a my() declaration (Ilya Zakharevich in 11085)
879 # Changes: 1.15: Nov 6, 2001 Michael G Schwern <schwern@pobox.com>
880 # + Updated 1.14 change log
881 # + Added *dbline explainatory comments
882 # + Mentioning perldebguts man page
883 # Changes: 1.16: Feb 15, 2002 Mark-Jason Dominus <mjd@plover.com>
884 # + $onetimeDump improvements
885 # Changes: 1.17: Feb 20, 2002 Richard Foley <richard.foley@rfi.net>
886 # Moved some code to cmd_[.]()'s for clarity and ease of handling,
887 # rationalised the following commands and added cmd_wrapper() to
888 # enable switching between old and frighteningly consistent new
889 # behaviours for diehards: 'o CommandSet=pre580' (sigh...)
890 # a(add), A(del) # action expr (added del by line)
891 # + b(add), B(del) # break [line] (was b,D)
892 # + w(add), W(del) # watch expr (was W,W)
893 # # added del by expr
894 # + h(summary), h h(long) # help (hh) (was h h,h)
895 # + m(methods), M(modules) # ... (was m,v)
896 # + o(option) # lc (was O)
897 # + v(view code), V(view Variables) # ... (was w,V)
898 # Changes: 1.18: Mar 17, 2002 Richard Foley <richard.foley@rfi.net>
899 # + fixed missing cmd_O bug
900 # Changes: 1.19: Mar 29, 2002 Spider Boardman
901 # + Added missing local()s -- DB::DB is called recursively.
902 # Changes: 1.20: Feb 17, 2003 Richard Foley <richard.foley@rfi.net>
903 # + pre'n'post commands no longer trashed with no args
904 # + watch val joined out of eval()
905 # Changes: 1.21: Jun 04, 2003 Joe McMahon <mcmahon@ibiblio.org>
906 # + Added comments and reformatted source. No bug fixes/enhancements.
907 # + Includes cleanup by Robin Barker and Jarkko Hietaniemi.
908 # Changes: 1.22 Jun 09, 2003 Alex Vandiver <alexmv@MIT.EDU>
909 # + Flush stdout/stderr before the debugger prompt is printed.
910 # Changes: 1.23: Dec 21, 2003 Dominique Quatravaux
911 # + Fix a side-effect of bug #24674 in the perl debugger ("odd taint bug")
912 # Changes: 1.24: Mar 03, 2004 Richard Foley <richard.foley@rfi.net>
913 # + Added command to save all debugger commands for sourcing later.
914 # + Added command to display parent inheritance tree of given class.
915 # + Fixed minor newline in history bug.
916 # Changes: 1.25: Apr 17, 2004 Richard Foley <richard.foley@rfi.net>
917 # + Fixed option bug (setting invalid options + not recognising valid short forms)
918 # Changes: 1.26: Apr 22, 2004 Richard Foley <richard.foley@rfi.net>
919 # + unfork the 5.8.x and 5.9.x debuggers.
920 # + whitespace and assertions call cleanup across versions
921 # + H * deletes (resets) history
922 # + i now handles Class + blessed objects
923 # Changes: 1.27: May 09, 2004 Richard Foley <richard.foley@rfi.net>
924 # + updated pod page references - clunky.
925 # + removed windowid restriction for forking into an xterm.
926 # + more whitespace again.
927 # + wrapped restart and enabled rerun [-n] (go back n steps) command.
928 # Changes: 1.28: Oct 12, 2004 Richard Foley <richard.foley@rfi.net>
929 # + Added threads support (inc. e and E commands)
930 ####################################################################
932 =head1 DEBUGGER INITIALIZATION
934 The debugger starts up in phases.
938 First, it initializes the environment it wants to run in: turning off
939 warnings during its own compilation, defining variables which it will need
940 to avoid warnings later, setting itself up to not exit when the program
941 terminates, and defaulting to printing return values for the C<r> command.
945 # Needed for the statement after exec():
947 # This BEGIN block is simply used to switch off warnings during debugger
948 # compiliation. Probably it would be better practice to fix the warnings,
949 # but this is how it's done at the moment.
954 } # Switch compilation warnings off until another BEGIN.
956 # test if assertions are supported and actived:
958 $ini_assertion = eval "sub asserting_test : assertion {1}; 1";
960 # $ini_assertion = undef => assertions unsupported,
961 # " = 1 => assertions supported
962 # print "\$ini_assertion=$ini_assertion\n";
965 local ($^W) = 0; # Switch run-time warnings off during init.
967 =head2 THREADS SUPPORT
969 If we are running under a threaded Perl, we require threads and threads::shared
970 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
971 threaded debugger control. C<-dt> can also be used to set this.
973 Each new thread will be announced and the debugger prompt will always inform
974 you of each new thread created. It will also indicate the thread id in which
975 we are currently running within the prompt like this:
979 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
980 command prompt. The prompt will show: C<[0]> when running under threads, but
981 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
983 While running under threads, when you set or delete a breakpoint (etc.), this
984 will apply to all threads, not just the currently running one. When you are
985 in a currently executing thread, you will stay there until it completes. With
986 the current implementation it is not currently possible to hop from one thread
989 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
991 Note that threading support was built into the debugger as of Perl version
992 C<5.8.6> and debugger version C<1.2.8>.
997 # ensure we can share our non-threaded variables or no-op
998 if ($ENV{PERL5DB_THREADED}) {
1000 require threads::shared;
1001 import threads::shared qw(share);
1005 print "Threads support enabled\n";
1012 # This would probably be better done with "use vars", but that wasn't around
1013 # when this code was originally written. (Neither was "use strict".) And on
1014 # the principle of not fiddling with something that was working, this was
1017 # These variables control the execution of 'dumpvar.pl'.
1018 $dumpvar::hashDepth,
1019 $dumpvar::arrayDepth,
1020 $dumpvar::dumpDBFiles,
1021 $dumpvar::dumpPackages,
1022 $dumpvar::quoteHighBit,
1023 $dumpvar::printUndef,
1024 $dumpvar::globPrint,
1025 $dumpvar::usageOnly,
1027 # used to save @ARGV and extract any debugger-related flags.
1030 # used to control die() reporting in diesignal()
1033 # used to prevent multiple entries to diesignal()
1034 # (if for instance diesignal() itself dies)
1037 # used to prevent the debugger from running nonstop
1043 foreach my $k (keys (%INC)) {
1044 &share(\$main::{'_<'.$filename});
1047 # Command-line + PERLLIB:
1048 # Save the contents of @INC before they are modified elsewhere.
1051 # This was an attempt to clear out the previous values of various
1052 # trapped errors. Apparently it didn't help. XXX More info needed!
1053 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
1055 # We set these variables to safe values. We don't want to blindly turn
1056 # off warnings, because other packages may still want them.
1057 $trace = $signal = $single = 0; # Uninitialized warning suppression
1058 # (local $^W cannot help - other packages!).
1060 # Default to not exiting when program finishes; print the return
1061 # value when the 'r' command is used to return from a subroutine.
1062 $inhibit_exit = $option{PrintRet} = 1;
1064 =head1 OPTION PROCESSING
1066 The debugger's options are actually spread out over the debugger itself and
1067 C<dumpvar.pl>; some of these are variables to be set, while others are
1068 subs to be called with a value. To try to make this a little easier to
1069 manage, the debugger uses a few data structures to define what options
1070 are legal and how they are to be processed.
1072 First, the C<@options> array defines the I<names> of all the options that
1079 hashDepth arrayDepth dumpDepth
1080 DumpDBFiles DumpPackages DumpReused
1081 compactDump veryCompact quote
1082 HighBit undefPrint globPrint
1083 PrintRet UsageOnly frame
1085 ReadLine NonStop LineInfo
1086 maxTraceLen recallCommand ShellBang
1087 pager tkRunning ornaments
1088 signalLevel warnLevel dieLevel
1089 inhibit_exit ImmediateStop bareStringify
1090 CreateTTY RemotePort windowSize
1091 DollarCaretP OnlyAssertions WarnAssertions
1094 @RememberOnROptions = qw(DollarCaretP OnlyAssertions);
1098 Second, C<optionVars> lists the variables that each option uses to save its
1104 hashDepth => \$dumpvar::hashDepth,
1105 arrayDepth => \$dumpvar::arrayDepth,
1106 CommandSet => \$CommandSet,
1107 DumpDBFiles => \$dumpvar::dumpDBFiles,
1108 DumpPackages => \$dumpvar::dumpPackages,
1109 DumpReused => \$dumpvar::dumpReused,
1110 HighBit => \$dumpvar::quoteHighBit,
1111 undefPrint => \$dumpvar::printUndef,
1112 globPrint => \$dumpvar::globPrint,
1113 UsageOnly => \$dumpvar::usageOnly,
1114 CreateTTY => \$CreateTTY,
1115 bareStringify => \$dumpvar::bareStringify,
1117 AutoTrace => \$trace,
1118 inhibit_exit => \$inhibit_exit,
1119 maxTraceLen => \$maxtrace,
1120 ImmediateStop => \$ImmediateStop,
1121 RemotePort => \$remoteport,
1122 windowSize => \$window,
1123 WarnAssertions => \$warnassertions,
1128 Third, C<%optionAction> defines the subroutine to be called to process each
1134 compactDump => \&dumpvar::compactDump,
1135 veryCompact => \&dumpvar::veryCompact,
1136 quote => \&dumpvar::quote,
1139 ReadLine => \&ReadLine,
1140 NonStop => \&NonStop,
1141 LineInfo => \&LineInfo,
1142 recallCommand => \&recallCommand,
1143 ShellBang => \&shellBang,
1145 signalLevel => \&signalLevel,
1146 warnLevel => \&warnLevel,
1147 dieLevel => \&dieLevel,
1148 tkRunning => \&tkRunning,
1149 ornaments => \&ornaments,
1150 RemotePort => \&RemotePort,
1151 DollarCaretP => \&DollarCaretP,
1152 OnlyAssertions=> \&OnlyAssertions,
1157 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1162 # Note that this list is not complete: several options not listed here
1163 # actually require that dumpvar.pl be loaded for them to work, but are
1164 # not in the table. A subsequent patch will correct this problem; for
1165 # the moment, we're just recommenting, and we are NOT going to change
1168 compactDump => 'dumpvar.pl',
1169 veryCompact => 'dumpvar.pl',
1170 quote => 'dumpvar.pl',
1175 There are a number of initialization-related variables which can be set
1176 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1177 variable. These are:
1181 =item C<$rl> - readline control XXX needs more explanation
1183 =item C<$warnLevel> - whether or not debugger takes over warning handling
1185 =item C<$dieLevel> - whether or not debugger takes over die handling
1187 =item C<$signalLevel> - whether or not debugger takes over signal handling
1189 =item C<$pre> - preprompt actions (array reference)
1191 =item C<$post> - postprompt actions (array reference)
1195 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1197 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1203 # These guys may be defined in $ENV{PERL5DB} :
1204 $rl = 1 unless defined $rl;
1205 $warnLevel = 1 unless defined $warnLevel;
1206 $dieLevel = 1 unless defined $dieLevel;
1207 $signalLevel = 1 unless defined $signalLevel;
1208 $pre = [] unless defined $pre;
1209 $post = [] unless defined $post;
1210 $pretype = [] unless defined $pretype;
1211 $CreateTTY = 3 unless defined $CreateTTY;
1212 $CommandSet = '580' unless defined $CommandSet;
1217 share($signalLevel);
1227 The default C<die>, C<warn>, and C<signal> handlers are set up.
1231 warnLevel($warnLevel);
1232 dieLevel($dieLevel);
1233 signalLevel($signalLevel);
1237 The pager to be used is needed next. We try to get it from the
1238 environment first. if it's not defined there, we try to find it in
1239 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1240 then call the C<pager()> function to save the pager name.
1244 # This routine makes sure $pager is set up so that '|' can use it.
1247 # If PAGER is defined in the environment, use it.
1251 # If not, see if Config.pm defines it.
1252 : eval { require Config }
1253 && defined $Config::Config{pager}
1254 ? $Config::Config{pager}
1256 # If not, fall back to 'more'.
1259 unless defined $pager;
1263 We set up the command to be used to access the man pages, the command
1264 recall character (C<!> unless otherwise defined) and the shell escape
1265 character (C<!> unless otherwise defined). Yes, these do conflict, and
1266 neither works in the debugger at the moment.
1272 # Set up defaults for command recall and shell escape (note:
1273 # these currently don't work in linemode debugging).
1274 &recallCommand("!") unless defined $prc;
1275 &shellBang("!") unless defined $psh;
1279 We then set up the gigantic string containing the debugger help.
1280 We also set the limit on the number of arguments we'll display during a
1287 # If we didn't get a default for the length of eval/stack trace args,
1289 $maxtrace = 400 unless defined $maxtrace;
1291 =head2 SETTING UP THE DEBUGGER GREETING
1293 The debugger I<greeting> helps to inform the user how many debuggers are
1294 running, and whether the current debugger is the primary or a child.
1296 If we are the primary, we just hang onto our pid so we'll have it when
1297 or if we start a child debugger. If we are a child, we'll set things up
1298 so we'll have a unique greeting and so the parent will give us our own
1301 We save the current contents of the C<PERLDB_PIDS> environment variable
1302 because we mess around with it. We'll also need to hang onto it because
1303 we'll need it if we restart.
1305 Child debuggers make a label out of the current PID structure recorded in
1306 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1307 yet so the parent will give them one later via C<resetterm()>.
1311 # Save the current contents of the environment; we're about to
1312 # much with it. We'll need this if we have to restart.
1313 $ini_pids = $ENV{PERLDB_PIDS};
1315 if ( defined $ENV{PERLDB_PIDS} ) {
1317 # We're a child. Make us a label out of the current PID structure
1318 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1319 # a term yet so the parent will give us one later via resetterm().
1321 my $env_pids = $ENV{PERLDB_PIDS};
1322 $pids = "[$env_pids]";
1324 # Unless we are on OpenVMS, all programs under the DCL shell run under
1327 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1331 $ENV{PERLDB_PIDS} .= "->$$";
1335 } ## end if (defined $ENV{PERLDB_PIDS...
1338 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1339 # child debugger, and mark us as the parent, so we'll know to set up
1340 # more TTY's is we have to.
1341 $ENV{PERLDB_PIDS} = "$$";
1348 # Sets up $emacs as a synonym for $slave_editor.
1349 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1351 =head2 READING THE RC FILE
1353 The debugger will read a file of initialization options if supplied. If
1354 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1358 # As noted, this test really doesn't check accurately that the debugger
1359 # is running at a terminal or not.
1361 if ( -e "/dev/tty" ) { # this is the wrong metric!
1362 $rcfile = ".perldb";
1365 $rcfile = "perldb.ini";
1370 The debugger does a safety test of the file to be read. It must be owned
1371 either by the current user or root, and must only be writable by the owner.
1375 # This wraps a safety test around "do" to read and evaluate the init file.
1377 # This isn't really safe, because there's a race
1378 # between checking and opening. The solution is to
1379 # open and fstat the handle, but then you have to read and
1380 # eval the contents. But then the silly thing gets
1381 # your lexical scope, which is unfortunate at best.
1385 # Just exactly what part of the word "CORE::" don't you understand?
1386 local $SIG{__WARN__};
1387 local $SIG{__DIE__};
1389 unless ( is_safe_file($file) ) {
1390 CORE::warn <<EO_GRIPE;
1391 perldb: Must not source insecure rcfile $file.
1392 You or the superuser must be the owner, and it must not
1393 be writable by anyone but its owner.
1396 } ## end unless (is_safe_file($file...
1399 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1400 } ## end sub safe_do
1402 # This is the safety test itself.
1404 # Verifies that owner is either real user or superuser and that no
1405 # one but owner may write to it. This function is of limited use
1406 # when called on a path instead of upon a handle, because there are
1407 # no guarantees that filename (by dirent) whose file (by ino) is
1408 # eventually accessed is the same as the one tested.
1409 # Assumes that the file's existence is not in doubt.
1412 stat($path) || return; # mysteriously vaporized
1413 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1415 return 0 if $uid != 0 && $uid != $<;
1416 return 0 if $mode & 022;
1418 } ## end sub is_safe_file
1420 # If the rcfile (whichever one we decided was the right one to read)
1421 # exists, we safely do it.
1423 safe_do("./$rcfile");
1426 # If there isn't one here, try the user's home directory.
1427 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1428 safe_do("$ENV{HOME}/$rcfile");
1431 # Else try the login directory.
1432 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1433 safe_do("$ENV{LOGDIR}/$rcfile");
1436 # If the PERLDB_OPTS variable has options in it, parse those out next.
1437 if ( defined $ENV{PERLDB_OPTS} ) {
1438 parse_options( $ENV{PERLDB_OPTS} );
1443 The last thing we do during initialization is determine which subroutine is
1444 to be used to obtain a new terminal when a new debugger is started. Right now,
1445 the debugger only handles X Windows and OS/2.
1449 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1450 # Works if you're running an xterm or xterm-like window, or you're on
1451 # OS/2. This may need some expansion: for instance, this doesn't handle
1452 # OS X Terminal windows.
1455 not defined &get_fork_TTY # no routine exists,
1456 and defined $ENV{TERM} # and we know what kind
1457 # of terminal this is,
1458 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1459 # and defined $ENV{WINDOWID} # and we know what window this is, <- wrong metric
1460 and defined $ENV{DISPLAY} # and what display it's on,
1463 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1464 } ## end if (not defined &get_fork_TTY...
1465 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1466 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1469 # untaint $^O, which may have been tainted by the last statement.
1470 # see bug [perl #24674]
1474 # Here begin the unreadable code. It needs fixing.
1476 =head2 RESTART PROCESSING
1478 This section handles the restart command. When the C<R> command is invoked, it
1479 tries to capture all of the state it can into environment variables, and
1480 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1481 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1482 the R command stuffed into the environment variables.
1484 PERLDB_RESTART - flag only, contains no restart data itself.
1485 PERLDB_HIST - command history, if it's available
1486 PERLDB_ON_LOAD - breakpoints set by the rc file
1487 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1488 PERLDB_VISITED - files that had breakpoints
1489 PERLDB_FILE_... - breakpoints for a file
1490 PERLDB_OPT - active options
1491 PERLDB_INC - the original @INC
1492 PERLDB_PRETYPE - preprompt debugger actions
1493 PERLDB_PRE - preprompt Perl code
1494 PERLDB_POST - post-prompt Perl code
1495 PERLDB_TYPEAHEAD - typeahead captured by readline()
1497 We chug through all these variables and plug the values saved in them
1498 back into the appropriate spots in the debugger.
1502 if ( exists $ENV{PERLDB_RESTART} ) {
1504 # We're restarting, so we don't need the flag that says to restart anymore.
1505 delete $ENV{PERLDB_RESTART};
1508 @hist = get_list('PERLDB_HIST');
1509 %break_on_load = get_list("PERLDB_ON_LOAD");
1510 %postponed = get_list("PERLDB_POSTPONE");
1514 share(%break_on_load);
1517 # restore breakpoints/actions
1518 my @had_breakpoints = get_list("PERLDB_VISITED");
1519 for ( 0 .. $#had_breakpoints ) {
1520 my %pf = get_list("PERLDB_FILE_$_");
1521 $postponed_file{ $had_breakpoints[$_] } = \%pf if %pf;
1525 my %opt = get_list("PERLDB_OPT");
1527 while ( ( $opt, $val ) = each %opt ) {
1528 $val =~ s/[\\\']/\\$1/g;
1529 parse_options("$opt'$val'");
1532 # restore original @INC
1533 @INC = get_list("PERLDB_INC");
1536 # return pre/postprompt actions and typeahead buffer
1537 $pretype = [ get_list("PERLDB_PRETYPE") ];
1538 $pre = [ get_list("PERLDB_PRE") ];
1539 $post = [ get_list("PERLDB_POST") ];
1540 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1541 } ## end if (exists $ENV{PERLDB_RESTART...
1543 =head2 SETTING UP THE TERMINAL
1545 Now, we'll decide how the debugger is going to interact with the user.
1546 If there's no TTY, we set the debugger to run non-stop; there's not going
1547 to be anyone there to enter commands.
1558 If there is a TTY, we have to determine who it belongs to before we can
1559 proceed. If this is a slave editor or graphical debugger (denoted by
1560 the first command-line switch being '-emacs'), we shift this off and
1561 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1567 # Is Perl being run from a slave editor or graphical debugger?
1568 # If so, don't use readline, and set $slave_editor = 1.
1570 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1571 $rl = 0, shift(@main::ARGV) if $slave_editor;
1573 #require Term::ReadLine;
1577 We then determine what the console should be on various systems:
1581 =item * Cygwin - We use C<stdin> instead of a separate device.
1585 if ( $^O eq 'cygwin' ) {
1587 # /dev/tty is binary. use stdin for textmode
1591 =item * Unix - use C</dev/tty>.
1595 elsif ( -e "/dev/tty" ) {
1596 $console = "/dev/tty";
1599 =item * Windows or MSDOS - use C<con>.
1603 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1607 =item * MacOS - use C<Dev:Console:Perl Debug> if this is the MPW version; C<Dev:
1610 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.
1614 elsif ( $^O eq 'MacOS' ) {
1615 if ( $MacPerl::Version !~ /MPW/ ) {
1617 "Dev:Console:Perl Debug"; # Separate window for application
1620 $console = "Dev:Console";
1622 } ## end elsif ($^O eq 'MacOS')
1624 =item * VMS - use C<sys$command>.
1630 # everything else is ...
1631 $console = "sys\$command";
1638 Several other systems don't use a specific console. We C<undef $console>
1639 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1640 with a slave editor, Epoc).
1644 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1646 # /dev/tty is binary. use stdin for textmode
1650 if ( $^O eq 'NetWare' ) {
1652 # /dev/tty is binary. use stdin for textmode
1656 # In OS/2, we need to use STDIN to get textmode too, even though
1657 # it pretty much looks like Unix otherwise.
1658 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1663 # EPOC also falls into the 'got to use STDIN' camp.
1664 if ( $^O eq 'epoc' ) {
1670 If there is a TTY hanging around from a parent, we use that as the console.
1674 $console = $tty if defined $tty;
1676 =head2 SOCKET HANDLING
1678 The debugger is capable of opening a socket and carrying out a debugging
1679 session over the socket.
1681 If C<RemotePort> was defined in the options, the debugger assumes that it
1682 should try to start a debugging session on that port. It builds the socket
1683 and then tries to connect the input and output filehandles to it.
1687 # Handle socket stuff.
1689 if ( defined $remoteport ) {
1691 # If RemotePort was defined in the options, connect input and output
1694 $OUT = new IO::Socket::INET(
1696 PeerAddr => $remoteport,
1699 if ( !$OUT ) { die "Unable to connect to remote host: $remoteport\n"; }
1701 } ## end if (defined $remoteport)
1705 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1706 this is probably a situation where multiple debuggers are running (for example,
1707 a backticked command that starts up another debugger). We create a new IN and
1708 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1716 # Two debuggers running (probably a system or a backtick that invokes
1717 # the debugger itself under the running one). create a new IN and OUT
1718 # filehandle, and do the necessary mojo to create a new tty if we
1719 # know how, and we can.
1720 create_IN_OUT(4) if $CreateTTY & 4;
1723 # If we have a console, check to see if there are separate ins and
1724 # outs to open. (They are assumed identical if not.)
1726 my ( $i, $o ) = split /,/, $console;
1727 $o = $i unless defined $o;
1729 # read/write on in, or just read, or read on STDIN.
1731 || open( IN, "<$i" )
1732 || open( IN, "<&STDIN" );
1734 # read/write/create/clobber out, or write/create/clobber out,
1735 # or merge with STDERR, or merge with STDOUT.
1737 || open( OUT, ">$o" )
1738 || open( OUT, ">&STDERR" )
1739 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1741 } ## end if ($console)
1742 elsif ( not defined $console ) {
1744 # No console. Open STDIN.
1745 open( IN, "<&STDIN" );
1747 # merge with STDERR, or with STDOUT.
1748 open( OUT, ">&STDERR" )
1749 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1750 $console = 'STDIN/OUT';
1751 } ## end elsif (not defined $console)
1753 # Keep copies of the filehandles so that when the pager runs, it
1754 # can close standard input without clobbering ours.
1755 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1756 } ## end elsif (from if(defined $remoteport))
1758 # Unbuffer DB::OUT. We need to see responses right away.
1759 my $previous = select($OUT);
1760 $| = 1; # for DB::OUT
1763 # Line info goes to debugger output unless pointed elsewhere.
1764 # Pointing elsewhere makes it possible for slave editors to
1765 # keep track of file and position. We have both a filehandle
1766 # and a I/O description to keep track of.
1767 $LINEINFO = $OUT unless defined $LINEINFO;
1768 $lineinfo = $console unless defined $lineinfo;
1769 # share($LINEINFO); # <- unable to share globs
1774 To finish initialization, we show the debugger greeting,
1775 and then call the C<afterinit()> subroutine if there is one.
1779 # Show the debugger greeting.
1780 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1781 unless ($runnonstop) {
1784 if ( $term_pid eq '-1' ) {
1785 print $OUT "\nDaughter DB session started...\n";
1788 print $OUT "\nLoading DB routines from $header\n";
1791 $slave_editor ? "enabled" : "available", ".\n"
1794 "\nEnter h or `h h' for help, or `$doccmd perldebug' for more help.\n\n";
1795 } ## end else [ if ($term_pid eq '-1')
1796 } ## end unless ($runnonstop)
1797 } ## end else [ if ($notty)
1799 # XXX This looks like a bug to me.
1800 # Why copy to @ARGS and then futz with @args?
1803 # Make sure backslashes before single quotes are stripped out, and
1804 # keep args unless they are numeric (XXX why?)
1805 # s/\'/\\\'/g; # removed while not justified understandably
1806 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1809 # If there was an afterinit() sub defined, call it. It will get
1810 # executed in our scope, so it can fiddle with debugger globals.
1811 if ( defined &afterinit ) { # May be defined in $rcfile
1815 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1818 ############################################################ Subroutines
1824 This gigantic subroutine is the heart of the debugger. Called before every
1825 statement, its job is to determine if a breakpoint has been reached, and
1826 stop if so; read commands from the user, parse them, and execute
1827 them, and hen send execution off to the next statement.
1829 Note that the order in which the commands are processed is very important;
1830 some commands earlier in the loop will actually alter the C<$cmd> variable
1831 to create other commands to be executed later. This is all highly I<optimized>
1832 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1833 see what's happening in any given command.
1839 # lock the debugger and get the thread id for the prompt
1842 if ($ENV{PERL5DB_THREADED}) {
1843 $tid = eval { "[".threads->self->tid."]" };
1846 # Check for whether we should be running continuously or not.
1847 # _After_ the perl program is compiled, $single is set to 1:
1848 if ( $single and not $second_time++ ) {
1850 # Options say run non-stop. Run until we get an interrupt.
1851 if ($runnonstop) { # Disable until signal
1852 # If there's any call stack in place, turn off single
1853 # stepping into subs throughout the stack.
1854 for ( $i = 0 ; $i <= $stack_depth ; ) {
1855 $stack[ $i++ ] &= ~1;
1858 # And we are now no longer in single-step mode.
1861 # If we simply returned at this point, we wouldn't get
1862 # the trace info. Fall on through.
1864 } ## end if ($runnonstop)
1866 elsif ($ImmediateStop) {
1868 # We are supposed to stop here; XXX probably a break.
1869 $ImmediateStop = 0; # We've processed it; turn it off
1870 $signal = 1; # Simulate an interrupt to force
1871 # us into the command loop
1873 } ## end if ($single and not $second_time...
1875 # If we're in single-step mode, or an interrupt (real or fake)
1876 # has occurred, turn off non-stop mode.
1877 $runnonstop = 0 if $single or $signal;
1879 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1880 # The code being debugged may have altered them.
1883 # Since DB::DB gets called after every line, we can use caller() to
1884 # figure out where we last were executing. Sneaky, eh? This works because
1885 # caller is returning all the extra information when called from the
1887 local ( $package, $filename, $line ) = caller;
1888 local $filename_ini = $filename;
1890 # set up the context for DB::eval, so it can properly execute
1891 # code on behalf of the user. We add the package in so that the
1892 # code is eval'ed in the proper package (not in the debugger!).
1893 local $usercontext =
1894 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' . "package $package;";
1896 # Create an alias to the active file magical array to simplify
1898 local (*dbline) = $main::{ '_<' . $filename };
1900 # we need to check for pseudofiles on Mac OS (these are files
1901 # not attached to a filename, but instead stored in Dev:Pseudo)
1902 if ( $^O eq 'MacOS' && $#dbline < 0 ) {
1903 $filename_ini = $filename = 'Dev:Pseudo';
1904 *dbline = $main::{ '_<' . $filename };
1907 # Last line in the program.
1908 local $max = $#dbline;
1910 # if we have something here, see if we should break.
1912 && ( ( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1915 # Stop if the stop criterion says to just stop.
1916 if ( $stop eq '1' ) {
1920 # It's a conditional stop; eval it in the user's context and
1921 # see if we should stop. If so, remove the one-time sigil.
1923 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1925 $dbline{$line} =~ s/;9($|\0)/$1/;
1927 } ## end if ($dbline{$line} && ...
1929 # Preserve the current stop-or-not, and see if any of the W
1930 # (watch expressions) has changed.
1931 my $was_signal = $signal;
1933 # If we have any watch expressions ...
1935 for ( my $n = 0 ; $n <= $#to_watch ; $n++ ) {
1936 $evalarg = $to_watch[$n];
1937 local $onetimeDump; # Tell DB::eval() to not output results
1939 # Fix context DB::eval() wants to return an array, but
1940 # we need a scalar here.
1941 my ($val) = join( "', '", &eval );
1942 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
1945 if ( $val ne $old_watch[$n] ) {
1947 # Yep! Show the difference, and fake an interrupt.
1950 Watchpoint $n:\t$to_watch[$n] changed:
1951 old value:\t$old_watch[$n]
1954 $old_watch[$n] = $val;
1955 } ## end if ($val ne $old_watch...
1956 } ## end for (my $n = 0 ; $n <= ...
1957 } ## end if ($trace & 2)
1959 =head2 C<watchfunction()>
1961 C<watchfunction()> is a function that can be defined by the user; it is a
1962 function which will be run on each entry to C<DB::DB>; it gets the
1963 current package, filename, and line as its parameters.
1965 The watchfunction can do anything it likes; it is executing in the
1966 debugger's context, so it has access to all of the debugger's internal
1967 data structures and functions.
1969 C<watchfunction()> can control the debugger's actions. Any of the following
1970 will cause the debugger to return control to the user's program after
1971 C<watchfunction()> executes:
1977 Returning a false value from the C<watchfunction()> itself.
1981 Altering C<$single> to a false value.
1985 Altering C<$signal> to a false value.
1989 Turning off the C<4> bit in C<$trace> (this also disables the
1990 check for C<watchfunction()>. This can be done with
1998 # If there's a user-defined DB::watchfunction, call it with the
1999 # current package, filename, and line. The function executes in
2001 if ( $trace & 4 ) { # User-installed watch
2003 if watchfunction( $package, $filename, $line )
2006 and not( $trace & ~4 );
2007 } ## end if ($trace & 4)
2009 # Pick up any alteration to $signal in the watchfunction, and
2010 # turn off the signal now.
2011 $was_signal = $signal;
2014 =head2 GETTING READY TO EXECUTE COMMANDS
2016 The debugger decides to take control if single-step mode is on, the
2017 C<t> command was entered, or the user generated a signal. If the program
2018 has fallen off the end, we set things up so that entering further commands
2019 won't cause trouble, and we say that the program is over.
2023 # Check to see if we should grab control ($single true,
2024 # trace set appropriately, or we got a signal).
2025 if ( $single || ( $trace & 1 ) || $was_signal ) {
2027 # Yes, grab control.
2028 if ($slave_editor) {
2030 # Tell the editor to update its position.
2031 $position = "\032\032$filename:$line:0\n";
2032 print_lineinfo($position);
2037 Special check: if we're in package C<DB::fake>, we've gone through the
2038 C<END> block at least once. We set up everything so that we can continue
2039 to enter commands and have a valid context to be in.
2043 elsif ( $package eq 'DB::fake' ) {
2045 # Fallen off the end already.
2048 Debugged program terminated. Use B<q> to quit or B<R> to restart,
2049 use B<o> I<inhibit_exit> to avoid stopping after program termination,
2050 B<h q>, B<h R> or B<h o> to get additional info.
2053 # Set the DB::eval context appropriately.
2056 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;'
2057 . "package $package;"; # this won't let them modify, alas
2058 } ## end elsif ($package eq 'DB::fake')
2062 If the program hasn't finished executing, we scan forward to the
2063 next executable line, print that out, build the prompt from the file and line
2064 number information, and print that.
2070 # Still somewhere in the midst of execution. Set up the
2072 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
2073 # Perl 5 ones (sorry, we don't print Klingon
2076 $prefix = $sub =~ /::/ ? "" : "${'package'}::";
2077 $prefix .= "$sub($filename:";
2078 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" );
2080 # Break up the prompt if it's really long.
2081 if ( length($prefix) > 30 ) {
2082 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
2088 $position = "$prefix$line$infix$dbline[$line]$after";
2091 # Print current line info, indenting if necessary.
2093 print_lineinfo( ' ' x $stack_depth,
2094 "$line:\t$dbline[$line]$after" );
2097 print_lineinfo($position);
2100 # Scan forward, stopping at either the end or the next
2102 for ( $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i )
2105 # Drop out on null statements, block closers, and comments.
2106 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
2108 # Drop out if the user interrupted us.
2111 # Append a newline if the line doesn't have one. Can happen
2112 # in eval'ed text, for instance.
2113 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" );
2115 # Next executable line.
2116 $incr_pos = "$prefix$i$infix$dbline[$i]$after";
2117 $position .= $incr_pos;
2120 # Print it indented if tracing is on.
2121 print_lineinfo( ' ' x $stack_depth,
2122 "$i:\t$dbline[$i]$after" );
2125 print_lineinfo($incr_pos);
2127 } ## end for ($i = $line + 1 ; $i...
2128 } ## end else [ if ($slave_editor)
2129 } ## end if ($single || ($trace...
2133 If there's an action to be executed for the line we stopped at, execute it.
2134 If there are any preprompt actions, execute those as well.
2138 # If there's an action, do it now.
2139 $evalarg = $action, &eval if $action;
2141 # Are we nested another level (e.g., did we evaluate a function
2142 # that had a breakpoint in it at the debugger prompt)?
2143 if ( $single || $was_signal ) {
2145 # Yes, go down a level.
2146 local $level = $level + 1;
2148 # Do any pre-prompt actions.
2149 foreach $evalarg (@$pre) {
2153 # Complain about too much recursion if we passed the limit.
2154 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
2157 # The line we're currently on. Set $incr to -1 to stay here
2158 # until we get a command that tells us to advance.
2160 $incr = -1; # for backward motion.
2162 # Tack preprompt debugger actions ahead of any actual input.
2163 @typeahead = ( @$pretype, @typeahead );
2165 =head2 WHERE ARE WE?
2167 XXX Relocate this section?
2169 The debugger normally shows the line corresponding to the current line of
2170 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2171 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2173 C<$incr> controls by how many lines the I<current> line should move forward
2174 after a command is executed. If set to -1, this indicates that the I<current>
2175 line shouldn't change.
2177 C<$start> is the I<current> line. It is used for things like knowing where to
2178 move forwards or backwards from when doing an C<L> or C<-> command.
2180 C<$max> tells the debugger where the last line of the current file is. It's
2181 used to terminate loops most often.
2183 =head2 THE COMMAND LOOP
2185 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2192 The outer part of the loop, starting at the C<CMD> label. This loop
2193 reads a command and then executes it.
2197 The inner part of the loop, starting at the C<PIPE> label. This part
2198 is wholly contained inside the C<CMD> block and only executes a command.
2199 Used to handle commands running inside a pager.
2203 So why have two labels to restart the loop? Because sometimes, it's easier to
2204 have a command I<generate> another command and then re-execute the loop to do
2205 the new command. This is faster, but perhaps a bit more convoluted.
2209 # The big command dispatch loop. It keeps running until the
2210 # user yields up control again.
2212 # If we have a terminal for input, and we get something back
2213 # from readline(), keep on processing.
2217 # We have a terminal, or can get one ...
2218 ( $term || &setterm ),
2220 # ... and it belogs to this PID or we get one for this PID ...
2221 ( $term_pid == $$ or resetterm(1) ),
2223 # ... and we got a line of command input ...
2226 "$pidprompt $tid DB"
2229 . ( '>' x $level ) . " "
2236 # ... try to execute the input as debugger commands.
2238 # Don't stop running.
2241 # No signal is active.
2244 # Handle continued commands (ending with \):
2245 $cmd =~ s/\\$/\n/ && do {
2246 $cmd .= &readline(" cont: ");
2250 =head4 The null command
2252 A newline entered by itself means I<re-execute the last command>. We grab the
2253 command out of C<$laststep> (where it was recorded previously), and copy it
2254 back into C<$cmd> to be executed below. If there wasn't any previous command,
2255 we'll do nothing below (no command will match). If there was, we also save it
2256 in the command history and fall through to allow the command parsing to pick
2261 # Empty input means repeat the last command.
2262 $cmd =~ /^$/ && ( $cmd = $laststep );
2263 chomp($cmd); # get rid of the annoying extra newline
2264 push( @hist, $cmd ) if length($cmd) > 1;
2265 push( @truehist, $cmd );
2269 # This is a restart point for commands that didn't arrive
2270 # via direct user input. It allows us to 'redo PIPE' to
2271 # re-execute command processing without reading a new command.
2273 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2274 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
2275 ($i) = split( /\s+/, $cmd );
2277 =head3 COMMAND ALIASES
2279 The debugger can create aliases for commands (these are stored in the
2280 C<%alias> hash). Before a command is executed, the command loop looks it up
2281 in the alias hash and substitutes the contents of the alias for the command,
2282 completely replacing it.
2286 # See if there's an alias for the command, and set it up if so.
2289 # Squelch signal handling; we want to keep control here
2290 # if something goes loco during the alias eval.
2291 local $SIG{__DIE__};
2292 local $SIG{__WARN__};
2294 # This is a command, so we eval it in the DEBUGGER's
2295 # scope! Otherwise, we can't see the special debugger
2296 # variables, or get to the debugger's subs. (Well, we
2297 # _could_, but why make it even more complicated?)
2298 eval "\$cmd =~ $alias{$i}";
2301 print $OUT "Couldn't evaluate `$i' alias: $@";
2304 } ## end if ($alias{$i})
2306 =head3 MAIN-LINE COMMANDS
2308 All of these commands work up to and after the program being debugged has
2313 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2314 try to execute further, cleaning any restart-related stuff out of the
2315 environment, and executing with the last value of C<$?>.
2319 $cmd =~ /^q$/ && do {
2327 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2331 $cmd =~ /^t$/ && do {
2334 print $OUT "Trace = "
2335 . ( ( $trace & 1 ) ? "on" : "off" ) . "\n";
2339 =head4 C<S> - list subroutines matching/not matching a pattern
2341 Walks through C<%sub>, checking to see whether or not to print the name.
2345 $cmd =~ /^S(\s+(!)?(.+))?$/ && do {
2347 $Srev = defined $2; # Reverse scan?
2348 $Spatt = $3; # The pattern (if any) to use.
2349 $Snocheck = !defined $1; # No args - print all subs.
2351 # Need to make these sane here.
2355 # Search through the debugger's magical hash of subs.
2356 # If $nocheck is true, just print the sub name.
2357 # Otherwise, check it against the pattern. We then use
2358 # the XOR trick to reverse the condition as required.
2359 foreach $subname ( sort( keys %sub ) ) {
2360 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2361 print $OUT $subname, "\n";
2367 =head4 C<X> - list variables in current package
2369 Since the C<V> command actually processes this, just change this to the
2370 appropriate C<V> command and fall through.
2374 $cmd =~ s/^X\b/V $package/;
2376 =head4 C<V> - list variables
2378 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2382 # Bare V commands get the currently-being-debugged package
2384 $cmd =~ /^V$/ && do {
2385 $cmd = "V $package";
2388 # V - show variables in package.
2389 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
2391 # Save the currently selected filehandle and
2392 # force output to debugger's filehandle (dumpvar
2393 # just does "print" for output).
2394 local ($savout) = select($OUT);
2396 # Grab package name and variables to dump.
2398 @vars = split( ' ', $2 );
2400 # If main::dumpvar isn't here, get it.
2401 do 'dumpvar.pl' unless defined &main::dumpvar;
2402 if ( defined &main::dumpvar ) {
2404 # We got it. Turn off subroutine entry/exit messages
2405 # for the moment, along with return values.
2409 # must detect sigpipe failures - not catching
2410 # then will cause the debugger to die.
2414 defined $option{dumpDepth}
2415 ? $option{dumpDepth}
2416 : -1, # assume -1 unless specified
2421 # The die doesn't need to include the $@, because
2422 # it will automatically get propagated for us.
2424 die unless $@ =~ /dumpvar print failed/;
2426 } ## end if (defined &main::dumpvar)
2429 # Couldn't load dumpvar.
2430 print $OUT "dumpvar.pl not available.\n";
2433 # Restore the output filehandle, and go round again.
2438 =head4 C<x> - evaluate and print an expression
2440 Hands the expression off to C<DB::eval>, setting it up to print the value
2441 via C<dumpvar.pl> instead of just printing it directly.
2445 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval()
2446 $onetimeDump = 'dump'; # main::dumpvar shows the output
2448 # handle special "x 3 blah" syntax XXX propagate
2449 # doc back to special variables.
2450 if ( $cmd =~ s/^\s*(\d+)(?=\s)/ / ) {
2451 $onetimedumpDepth = $1;
2455 =head4 C<m> - print methods
2457 Just uses C<DB::methods> to determine what methods are available.
2461 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do {
2466 # m expr - set up DB::eval to do the work
2467 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval()
2468 $onetimeDump = 'methods'; # method output gets used there
2471 =head4 C<f> - switch files
2475 $cmd =~ /^f\b\s*(.*)/ && do {
2479 # help for no arguments (old-style was return from sub).
2482 "The old f command is now the r command.\n"; # hint
2483 print $OUT "The new f command switches filenames.\n";
2485 } ## end if (!$file)
2487 # if not in magic file list, try a close match.
2488 if ( !defined $main::{ '_<' . $file } ) {
2489 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2491 $try = substr( $try, 2 );
2492 print $OUT "Choosing $try matching `$file':\n";
2495 } ## end if (($try) = grep(m#^_<.*$file#...
2496 } ## end if (!defined $main::{ ...
2498 # If not successfully switched now, we failed.
2499 if ( !defined $main::{ '_<' . $file } ) {
2500 print $OUT "No file matching `$file' is loaded.\n";
2504 # We switched, so switch the debugger internals around.
2505 elsif ( $file ne $filename ) {
2506 *dbline = $main::{ '_<' . $file };
2511 } ## end elsif ($file ne $filename)
2513 # We didn't switch; say we didn't.
2515 print $OUT "Already in $file.\n";
2520 =head4 C<.> - return to last-executed line.
2522 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2523 and then we look up the line in the magical C<%dbline> hash.
2528 $cmd =~ /^\.$/ && do {
2529 $incr = -1; # stay at current line
2531 # Reset everything to the old location.
2533 $filename = $filename_ini;
2534 *dbline = $main::{ '_<' . $filename };
2538 print_lineinfo($position);
2542 =head4 C<-> - back one window
2544 We change C<$start> to be one window back; if we go back past the first line,
2545 we set it to be the first line. We ser C<$incr> to put us back at the
2546 currently-executing line, and then put a C<l $start +> (list one window from
2547 C<$start>) in C<$cmd> to be executed later.
2551 # - - back a window.
2552 $cmd =~ /^-$/ && do {
2554 # back up by a window; go to 1 if back too far.
2555 $start -= $incr + $window + 1;
2556 $start = 1 if $start <= 0;
2557 $incr = $window - 1;
2559 # Generate and execute a "l +" command (handled below).
2560 $cmd = 'l ' . ($start) . '+';
2563 =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>, {, {{>
2565 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2566 problems, most notably that the default case of several commands destroying
2567 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2568 retain the old commands for those who were used to using them or who preferred
2569 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2570 deal with them instead of processing them in-line.
2574 # All of these commands were remapped in perl 5.8.0;
2575 # we send them off to the secondary dispatcher (see below).
2576 $cmd =~ /^([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do {
2577 &cmd_wrapper( $1, $2, $line );
2581 =head4 C<y> - List lexicals in higher scope
2583 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2584 above the current one and then displays then using C<dumpvar.pl>.
2588 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do {
2590 # See if we've got the necessary support.
2591 eval { require PadWalker; PadWalker->VERSION(0.08) }
2594 ? "PadWalker module not found - please install\n"
2599 # Load up dumpvar if we don't have it. If we can, that is.
2600 do 'dumpvar.pl' unless defined &main::dumpvar;
2601 defined &main::dumpvar
2602 or print $OUT "dumpvar.pl not available.\n"
2605 # Got all the modules we need. Find them and print them.
2606 my @vars = split( ' ', $2 || '' );
2609 my $h = eval { PadWalker::peek_my( ( $1 || 0 ) + 1 ) };
2611 # Oops. Can't find it.
2612 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2614 # Show the desired vars with dumplex().
2615 my $savout = select($OUT);
2617 # Have dumplex dump the lexicals.
2618 dumpvar::dumplex( $_, $h->{$_},
2619 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
2626 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2628 All of the commands below this point don't work after the program being
2629 debugged has ended. All of them check to see if the program has ended; this
2630 allows the commands to be relocated without worrying about a 'line of
2631 demarcation' above which commands can be entered anytime, and below which
2634 =head4 C<n> - single step, but don't trace down into subs
2636 Done by setting C<$single> to 2, which forces subs to execute straight through
2637 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2638 so a null command knows what to re-execute.
2643 $cmd =~ /^n$/ && do {
2644 end_report(), next CMD if $finished and $level <= 1;
2646 # Single step, but don't enter subs.
2649 # Save for empty command (repeat last).
2654 =head4 C<s> - single-step, entering subs
2656 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2657 subs. Also saves C<s> as C<$lastcmd>.
2662 $cmd =~ /^s$/ && do {
2664 # Get out and restart the command loop if program
2666 end_report(), next CMD if $finished and $level <= 1;
2668 # Single step should enter subs.
2671 # Save for empty command (repeat last).
2676 =head4 C<c> - run continuously, setting an optional breakpoint
2678 Most of the code for this command is taken up with locating the optional
2679 breakpoint, which is either a subroutine name or a line number. We set
2680 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2681 in this and all call levels above this one.
2685 # c - start continuous execution.
2686 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do {
2688 # Hey, show's over. The debugged program finished
2689 # executing already.
2690 end_report(), next CMD if $finished and $level <= 1;
2692 # Capture the place to put a one-time break.
2695 # Probably not needed, since we finish an interactive
2696 # sub-session anyway...
2697 # local $filename = $filename;
2698 # local *dbline = *dbline; # XXX Would this work?!
2700 # The above question wonders if localizing the alias
2701 # to the magic array works or not. Since it's commented
2702 # out, we'll just leave that to speculation for now.
2704 # If the "subname" isn't all digits, we'll assume it
2705 # is a subroutine name, and try to find it.
2706 if ( $subname =~ /\D/ ) { # subroutine name
2707 # Qualify it to the current package unless it's
2708 # already qualified.
2709 $subname = $package . "::" . $subname
2710 unless $subname =~ /::/;
2712 # find_sub will return "file:line_number" corresponding
2713 # to where the subroutine is defined; we call find_sub,
2714 # break up the return value, and assign it in one
2716 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2718 # Force the line number to be numeric.
2721 # If we got a line number, we found the sub.
2724 # Switch all the debugger's internals around so
2725 # we're actually working with that file.
2727 *dbline = $main::{ '_<' . $filename };
2729 # Mark that there's a breakpoint in this file.
2730 $had_breakpoints{$filename} |= 1;
2732 # Scan forward to the first executable line
2733 # after the 'sub whatever' line.
2735 ++$i while $dbline[$i] == 0 && $i < $max;
2738 # We didn't find a sub by that name.
2740 print $OUT "Subroutine $subname not found.\n";
2743 } ## end if ($subname =~ /\D/)
2745 # At this point, either the subname was all digits (an
2746 # absolute line-break request) or we've scanned through
2747 # the code following the definition of the sub, looking
2748 # for an executable, which we may or may not have found.
2750 # If $i (which we set $subname from) is non-zero, we
2751 # got a request to break at some line somewhere. On
2752 # one hand, if there wasn't any real subroutine name
2753 # involved, this will be a request to break in the current
2754 # file at the specified line, so we have to check to make
2755 # sure that the line specified really is breakable.
2757 # On the other hand, if there was a subname supplied, the
2758 # preceding block has moved us to the proper file and
2759 # location within that file, and then scanned forward
2760 # looking for the next executable line. We have to make
2761 # sure that one was found.
2763 # On the gripping hand, we can't do anything unless the
2764 # current value of $i points to a valid breakable line.
2769 if ( $dbline[$i] == 0 ) {
2770 print $OUT "Line $i not breakable.\n";
2774 # Yes. Set up the one-time-break sigil.
2775 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2778 # Turn off stack tracing from here up.
2779 for ( $i = 0 ; $i <= $stack_depth ; ) {
2780 $stack[ $i++ ] &= ~1;
2785 =head4 C<r> - return from a subroutine
2787 For C<r> to work properly, the debugger has to stop execution again
2788 immediately after the return is executed. This is done by forcing
2789 single-stepping to be on in the call level above the current one. If
2790 we are printing return values when a C<r> is executed, set C<$doret>
2791 appropriately, and force us out of the command loop.
2795 # r - return from the current subroutine.
2796 $cmd =~ /^r$/ && do {
2798 # Can't do anythign if the program's over.
2799 end_report(), next CMD if $finished and $level <= 1;
2801 # Turn on stack trace.
2802 $stack[$stack_depth] |= 1;
2804 # Print return value unless the stack is empty.
2805 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2809 =head4 C<T> - stack trace
2811 Just calls C<DB::print_trace>.
2815 $cmd =~ /^T$/ && do {
2816 print_trace( $OUT, 1 ); # skip DB
2820 =head4 C<w> - List window around current line.
2822 Just calls C<DB::cmd_w>.
2826 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w( 'w', $1 ); next CMD; };
2828 =head4 C<W> - watch-expression processing.
2830 Just calls C<DB::cmd_W>.
2834 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W( 'W', $1 ); next CMD; };
2836 =head4 C</> - search forward for a string in the source
2838 We take the argument and treat it as a pattern. If it turns out to be a
2839 bad one, we return the error we got from trying to C<eval> it and exit.
2840 If not, we create some code to do the search and C<eval> it so it can't
2845 $cmd =~ /^\/(.*)$/ && do {
2847 # The pattern as a string.
2850 # Remove the final slash.
2851 $inpat =~ s:([^\\])/$:$1:;
2853 # If the pattern isn't null ...
2854 if ( $inpat ne "" ) {
2856 # Turn of warn and die procesing for a bit.
2857 local $SIG{__DIE__};
2858 local $SIG{__WARN__};
2860 # Create the pattern.
2861 eval '$inpat =~ m' . "\a$inpat\a";
2864 # Oops. Bad pattern. No biscuit.
2865 # Print the eval error and go back for more
2871 } ## end if ($inpat ne "")
2873 # Set up to stop on wrap-around.
2876 # Don't move off the current line.
2879 # Done in eval so nothing breaks if the pattern
2880 # does something weird.
2883 # Move ahead one line.
2886 # Wrap if we pass the last line.
2887 $start = 1 if ($start > $max);
2889 # Stop if we have gotten back to this line again,
2890 last if ($start == $end);
2892 # A hit! (Note, though, that we are doing
2893 # case-insensitive matching. Maybe a qr//
2894 # expression would be better, so the user could
2895 # do case-sensitive matching if desired.
2896 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2897 if ($slave_editor) {
2898 # Handle proper escaping in the slave.
2899 print $OUT "\032\032$filename:$start:0\n";
2902 # Just print the line normally.
2903 print $OUT "$start:\t",$dbline[$start],"\n";
2905 # And quit since we found something.
2910 # If we wrapped, there never was a match.
2911 print $OUT "/$pat/: not found\n" if ( $start == $end );
2915 =head4 C<?> - search backward for a string in the source
2917 Same as for C</>, except the loop runs backwards.
2921 # ? - backward pattern search.
2922 $cmd =~ /^\?(.*)$/ && do {
2924 # Get the pattern, remove trailing question mark.
2926 $inpat =~ s:([^\\])\?$:$1:;
2928 # If we've got one ...
2929 if ( $inpat ne "" ) {
2931 # Turn off die & warn handlers.
2932 local $SIG{__DIE__};
2933 local $SIG{__WARN__};
2934 eval '$inpat =~ m' . "\a$inpat\a";
2938 # Ouch. Not good. Print the error.
2943 } ## end if ($inpat ne "")
2945 # Where we are now is where to stop after wraparound.
2948 # Don't move away from this line.
2951 # Search inside the eval to prevent pattern badness
2958 # Wrap if we pass the first line.
2960 $start = $max if ($start <= 0);
2962 # Quit if we get back where we started,
2963 last if ($start == $end);
2966 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2967 if ($slave_editor) {
2968 # Yep, follow slave editor requirements.
2969 print $OUT "\032\032$filename:$start:0\n";
2972 # Yep, just print normally.
2973 print $OUT "$start:\t",$dbline[$start],"\n";
2981 # Say we failed if the loop never found anything,
2982 print $OUT "?$pat?: not found\n" if ( $start == $end );
2986 =head4 C<$rc> - Recall command
2988 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2989 that the terminal supports history). It find the the command required, puts it
2990 into C<$cmd>, and redoes the loop to execute it.
2994 # $rc - recall command.
2995 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do {
2997 # No arguments, take one thing off history.
2998 pop(@hist) if length($cmd) > 1;
3000 # Relative (- found)?
3001 # Y - index back from most recent (by 1 if bare minus)
3002 # N - go to that particular command slot or the last
3003 # thing if nothing following.
3004 $i = $1 ? ( $#hist - ( $2 || 1 ) ) : ( $2 || $#hist );
3006 # Pick out the command desired.
3009 # Print the command to be executed and restart the loop
3010 # with that command in the buffer.
3011 print $OUT $cmd, "\n";
3015 =head4 C<$sh$sh> - C<system()> command
3017 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
3018 C<STDOUT> from getting messed up.
3022 # $sh$sh - run a shell command (if it's all ASCII).
3023 # Can't run shell commands with Unicode in the debugger, hmm.
3024 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do {
3031 =head4 C<$rc I<pattern> $rc> - Search command history
3033 Another command to manipulate C<@hist>: this one searches it with a pattern.
3034 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
3038 # $rc pattern $rc - find a command in the history.
3039 $cmd =~ /^$rc([^$rc].*)$/ && do {
3041 # Create the pattern to use.
3044 # Toss off last entry if length is >1 (and it always is).
3045 pop(@hist) if length($cmd) > 1;
3047 # Look backward through the history.
3048 for ( $i = $#hist ; $i ; --$i ) {
3050 # Stop if we find it.
3051 last if $hist[$i] =~ /$pat/;
3057 print $OUT "No such command!\n\n";
3061 # Found it. Put it in the buffer, print it, and process it.
3063 print $OUT $cmd, "\n";
3067 =head4 C<$sh> - Invoke a shell
3069 Uses C<DB::system> to invoke a shell.
3073 # $sh - start a shell.
3074 $cmd =~ /^$sh$/ && do {
3076 # Run the user's shell. If none defined, run Bourne.
3077 # We resume execution when the shell terminates.
3078 &system( $ENV{SHELL} || "/bin/sh" );
3082 =head4 C<$sh I<command>> - Force execution of a command in a shell
3084 Like the above, but the command is passed to the shell. Again, we use
3085 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3089 # $sh command - start a shell and run a command in it.
3090 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do {
3092 # XXX: using csh or tcsh destroys sigint retvals!
3093 #&system($1); # use this instead
3095 # use the user's shell, or Bourne if none defined.
3096 &system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3100 =head4 C<H> - display commands in history
3102 Prints the contents of C<@hist> (if any).
3106 $cmd =~ /^H\b\s*\*/ && do {
3107 @hist = @truehist = ();
3108 print $OUT "History cleansed\n";
3112 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
3114 # Anything other than negative numbers is ignored by
3115 # the (incorrect) pattern, so this test does nothing.
3116 $end = $2 ? ( $#hist - $2 ) : 0;
3118 # Set to the minimum if less than zero.
3119 $hist = 0 if $hist < 0;
3121 # Start at the end of the array.
3122 # Stay in while we're still above the ending value.
3123 # Tick back by one each time around the loop.
3124 for ( $i = $#hist ; $i > $end ; $i-- ) {
3126 # Print the command unless it has no arguments.
3127 print $OUT "$i: ", $hist[$i], "\n"
3128 unless $hist[$i] =~ /^.?$/;
3133 =head4 C<man, doc, perldoc> - look up documentation
3135 Just calls C<runman()> to print the appropriate document.
3139 # man, perldoc, doc - show manual pages.
3140 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do {
3147 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3148 the bottom of the loop.
3152 # p - print (no args): print $_.
3153 $cmd =~ s/^p$/print {\$DB::OUT} \$_/;
3155 # p - print the given expression.
3156 $cmd =~ s/^p\b/print {\$DB::OUT} /;
3158 =head4 C<=> - define command alias
3160 Manipulates C<%alias> to add or list command aliases.
3164 # = - set up a command alias.
3165 $cmd =~ s/^=\s*// && do {
3167 if ( length $cmd == 0 ) {
3169 # No args, get current aliases.
3170 @keys = sort keys %alias;
3172 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3174 # Creating a new alias. $k is alias name, $v is
3177 # can't use $_ or kill //g state
3178 for my $x ( $k, $v ) {
3180 # Escape "alarm" characters.
3184 # Substitute key for value, using alarm chars
3185 # as separators (which is why we escaped them in
3187 $alias{$k} = "s\a$k\a$v\a";
3189 # Turn off standard warn and die behavior.
3190 local $SIG{__DIE__};
3191 local $SIG{__WARN__};
3194 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3196 # Nope. Bad alias. Say so and get out.
3197 print $OUT "Can't alias $k to $v: $@\n";
3202 # We'll only list the new one.
3204 } ## end elsif (my ($k, $v) = ($cmd...
3206 # The argument is the alias to list.
3214 # Messy metaquoting: Trim the substiution code off.
3215 # We use control-G as the delimiter because it's not
3216 # likely to appear in the alias.
3217 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3220 print $OUT "$k\t= $1\n";
3222 elsif ( defined $alias{$k} ) {
3224 # Couldn't trim it off; just print the alias code.
3225 print $OUT "$k\t$alias{$k}\n";
3230 print "No alias for $k\n";
3232 } ## end for my $k (@keys)
3236 =head4 C<source> - read commands from a file.
3238 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3243 # source - read commands from a file (or pipe!) and execute.
3244 $cmd =~ /^source\s+(.*\S)/ && do {
3245 if ( open my $fh, $1 ) {
3247 # Opened OK; stick it in the list of file handles.
3253 &warn("Can't execute `$1': $!\n");
3258 =head4 C<save> - send current history to a file
3260 Takes the complete history, (not the shrunken version you see with C<H>),
3261 and saves it to the given filename, so it can be replayed using C<source>.
3263 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3267 # save source - write commands to a file for later use
3268 $cmd =~ /^save\s*(.*)$/ && do {
3269 my $file = $1 || '.perl5dbrc'; # default?
3270 if ( open my $fh, "> $file" ) {
3272 # chomp to remove extraneous newlines from source'd files
3273 chomp( my @truelist =
3274 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3276 print $fh join( "\n", @truelist );
3277 print "commands saved in $file\n";
3280 &warn("Can't save debugger commands in '$1': $!\n");
3285 =head4 C<R> - restart
3287 Restart the debugger session.
3289 =head4 C<rerun> - rerun the current session
3291 Return to any given position in the B<true>-history list
3295 # R - restart execution.
3296 # rerun - controlled restart execution.
3297 $cmd =~ /^(R|rerun\s*(.*))$/ && do {
3298 my @args = ($1 eq 'R' ? restart() : rerun($2));
3300 # Close all non-system fds for a clean restart. A more
3301 # correct method would be to close all fds that were not
3302 # open when the process started, but this seems to be
3303 # hard. See "debugger 'R'estart and open database
3304 # connections" on p5p.
3306 my $max_fd = 1024; # default if POSIX can't be loaded
3307 if (eval { require POSIX }) {
3308 $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX());
3311 if (defined $max_fd) {
3312 foreach ($^F+1 .. $max_fd-1) {
3313 next unless open FD_TO_CLOSE, "<&=$_";
3318 # And run Perl again. We use exec() to keep the
3319 # PID stable (and that way $ini_pids is still valid).
3320 exec(@args) || print $OUT "exec failed: $!\n";
3325 =head4 C<|, ||> - pipe output through the pager.
3327 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3328 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3329 pipe to the pager (restoring the output filehandles if this fails). If this
3330 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3331 set C<$signal>, sending us back into the debugger.
3333 We then trim off the pipe symbols and C<redo> the command loop at the
3334 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3339 # || - run command in the pager, with output to DB::OUT.
3340 $cmd =~ /^\|\|?\s*[^|]/ && do {
3341 if ( $pager =~ /^\|/ ) {
3343 # Default pager is into a pipe. Redirect I/O.
3344 open( SAVEOUT, ">&STDOUT" )
3345 || &warn("Can't save STDOUT");
3346 open( STDOUT, ">&OUT" )
3347 || &warn("Can't redirect STDOUT");
3348 } ## end if ($pager =~ /^\|/)
3351 # Not into a pipe. STDOUT is safe.
3352 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3355 # Fix up environment to record we have less if so.
3358 unless ( $piped = open( OUT, $pager ) ) {
3360 # Couldn't open pipe to pager.
3361 &warn("Can't pipe output to `$pager'");
3362 if ( $pager =~ /^\|/ ) {
3364 # Redirect I/O back again.
3365 open( OUT, ">&STDOUT" ) # XXX: lost message
3366 || &warn("Can't restore DB::OUT");
3367 open( STDOUT, ">&SAVEOUT" )
3368 || &warn("Can't restore STDOUT");
3370 } ## end if ($pager =~ /^\|/)
3373 # Redirect I/O. STDOUT already safe.
3374 open( OUT, ">&STDOUT" ) # XXX: lost message
3375 || &warn("Can't restore DB::OUT");
3378 } ## end unless ($piped = open(OUT,...
3380 # Set up broken-pipe handler if necessary.
3381 $SIG{PIPE} = \&DB::catch
3383 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
3385 # Save current filehandle, unbuffer out, and put it back.
3386 $selected = select(OUT);
3389 # Don't put it back if pager was a pipe.
3390 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
3392 # Trim off the pipe symbols and run the command now.
3393 $cmd =~ s/^\|+\s*//;
3397 =head3 END OF COMMAND PARSING
3399 Anything left in C<$cmd> at this point is a Perl expression that we want to
3400 evaluate. We'll always evaluate in the user's context, and fully qualify
3401 any variables we might want to address in the C<DB> package.
3405 # t - turn trace on.
3406 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3408 # s - single-step. Remember the last command was 's'.
3409 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' };
3411 # n - single-step, but not into subs. Remember last command
3413 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' };
3417 # Make sure the flag that says "the debugger's running" is
3418 # still on, to make sure we get control again.
3419 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3421 # Run *our* eval that executes in the caller's context.
3424 # Turn off the one-time-dump stuff now.
3426 $onetimeDump = undef;
3427 $onetimedumpDepth = undef;
3429 elsif ( $term_pid == $$ ) {
3430 eval { # May run under miniperl, when not available...
3435 # XXX If this is the master pid, print a newline.
3438 } ## end while (($term || &setterm...
3440 =head3 POST-COMMAND PROCESSING
3442 After each command, we check to see if the command output was piped anywhere.
3443 If so, we go through the necessary code to unhook the pipe and go back to
3444 our standard filehandles for input and output.
3450 # At the end of every command:
3453 # Unhook the pipe mechanism now.
3454 if ( $pager =~ /^\|/ ) {
3456 # No error from the child.
3459 # we cannot warn here: the handle is missing --tchrist
3460 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
3462 # most of the $? crud was coping with broken cshisms
3463 # $? is explicitly set to 0, so this never runs.
3465 print SAVEOUT "Pager `$pager' failed: ";
3467 print SAVEOUT "shell returned -1\n";
3470 print SAVEOUT ( $? & 127 )
3471 ? " (SIG#" . ( $? & 127 ) . ")"
3472 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3475 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3479 # Reopen filehandle for our output (if we can) and
3480 # restore STDOUT (if we can).
3481 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3482 open( STDOUT, ">&SAVEOUT" )
3483 || &warn("Can't restore STDOUT");
3485 # Turn off pipe exception handler if necessary.
3486 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
3488 # Will stop ignoring SIGPIPE if done like nohup(1)
3489 # does SIGINT but Perl doesn't give us a choice.
3490 } ## end if ($pager =~ /^\|/)
3493 # Non-piped "pager". Just restore STDOUT.
3494 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3497 # Close filehandle pager was using, restore the normal one
3500 select($selected), $selected = "" unless $selected eq "";
3504 } ## end if ($piped)
3507 =head3 COMMAND LOOP TERMINATION
3509 When commands have finished executing, we come here. If the user closed the
3510 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3511 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3512 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3513 The interpreter will then execute the next line and then return control to us
3518 # No more commands? Quit.
3519 $fall_off_end = 1 unless defined $cmd; # Emulate `q' on EOF
3521 # Evaluate post-prompt commands.
3522 foreach $evalarg (@$post) {
3525 } # if ($single || $signal)
3527 # Put the user's globals back where you found them.
3528 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3532 # The following code may be executed now:
3537 C<sub> is called whenever a subroutine call happens in the program being
3538 debugged. The variable C<$DB::sub> contains the name of the subroutine
3541 The core function of this subroutine is to actually call the sub in the proper
3542 context, capturing its output. This of course causes C<DB::DB> to get called
3543 again, repeating until the subroutine ends and returns control to C<DB::sub>
3544 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3545 return value, and returns its captured copy of the return value as its own
3546 return value. The value then feeds back into the program being debugged as if
3547 C<DB::sub> hadn't been there at all.
3549 C<sub> does all the work of printing the subroutine entry and exit messages
3550 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3551 and also prints the return value if needed (for the C<r> command and if
3552 the 16 bit is set in C<$frame>).
3554 It also tracks the subroutine call depth by saving the current setting of
3555 C<$single> in the C<@stack> package global; if this exceeds the value in
3556 C<$deep>, C<sub> automatically turns on printing of the current depth by
3557 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
3558 of stop/don't stop on entry to subs set as it currently is set.
3560 =head3 C<caller()> support
3562 If C<caller()> is called from the package C<DB>, it provides some
3563 additional data, in the following order:
3569 The package name the sub was in
3571 =item * C<$filename>
3573 The filename it was defined in
3577 The line number it was defined on
3579 =item * C<$subroutine>
3581 The subroutine name; C<(eval)> if an C<eval>().
3585 1 if it has arguments, 0 if not
3587 =item * C<$wantarray>
3589 1 if array context, 0 if scalar context
3591 =item * C<$evaltext>
3593 The C<eval>() text, if any (undefined for C<eval BLOCK>)
3595 =item * C<$is_require>
3597 frame was created by a C<use> or C<require> statement
3601 pragma information; subject to change between versions
3605 pragma information; subject to change between versions
3607 =item * C<@DB::args>
3609 arguments with which the subroutine was invoked
3617 # lock ourselves under threads
3620 # Whether or not the autoloader was running, a scalar to put the
3621 # sub's return value in (if needed), and an array to put the sub's
3622 # return value in (if needed).
3623 my ( $al, $ret, @ret ) = "";
3624 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3625 print "creating new thread\n";
3628 # If the last ten characters are C'::AUTOLOAD', note we've traced
3629 # into AUTOLOAD for $sub.
3630 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3634 # We stack the stack pointer and then increment it to protect us
3635 # from a situation that might unwind a whole bunch of call frames
3636 # at once. Localizing the stack pointer means that it will automatically
3637 # unwind the same amount when multiple stack frames are unwound.
3638 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3641 $#stack = $stack_depth;
3643 # Save current single-step setting.
3644 $stack[-1] = $single;
3646 # Turn off all flags except single-stepping.
3649 # If we've gotten really deeply recursed, turn on the flag that will
3650 # make us stop with the 'deep recursion' message.
3651 $single |= 4 if $stack_depth == $deep;
3653 # If frame messages are on ...
3655 $frame & 4 # Extended frame entry message
3657 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3659 # Why -1? But it works! :-(
3660 # Because print_trace will call add 1 to it and then call
3661 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3663 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3665 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3667 # standard frame entry message
3671 # Determine the sub's return type,and capture approppriately.
3674 # Called in array context. call sub and capture output.
3675 # DB::DB will recursively get control again if appropriate; we'll come
3676 # back here when the sub is finished.
3679 eval { @ret = &$sub; };
3682 $signal = 1 unless $warnassertions;
3689 # Pop the single-step value back off the stack.
3690 $single |= $stack[ $stack_depth-- ];
3692 # Check for exit trace messages...
3694 $frame & 4 # Extended exit message
3696 print_lineinfo( ' ' x $stack_depth, "out " ),
3697 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3699 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3701 # Standard exit message
3705 # Print the return info if we need to.
3706 if ( $doret eq $stack_depth or $frame & 16 ) {
3708 # Turn off output record separator.
3710 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3712 # Indent if we're printing because of $frame tracing.
3713 print $fh ' ' x $stack_depth if $frame & 16;
3715 # Print the return value.
3716 print $fh "list context return from $sub:\n";
3717 dumpit( $fh, \@ret );
3719 # And don't print it again.
3721 } ## end if ($doret eq $stack_depth...
3722 # And we have to return the return value now.
3724 } ## end if (wantarray)
3732 # Save the value if it's wanted at all.
3737 $signal = 1 unless $warnassertions;
3739 $ret = undef unless defined wantarray;
3742 if ( defined wantarray ) {
3744 # Save the value if it's wanted at all.
3749 # Void return, explicitly.
3755 # Pop the single-step value off the stack.
3756 $single |= $stack[ $stack_depth-- ];
3758 # If we're doing exit messages...
3760 $frame & 4 # Extended messsages
3762 print_lineinfo( ' ' x $stack_depth, "out " ),
3763 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3765 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3771 # If we are supposed to show the return value... same as before.
3772 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
3774 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3775 print $fh ( ' ' x $stack_depth ) if $frame & 16;
3778 ? "scalar context return from $sub: "
3779 : "void context return from $sub\n"
3781 dumpit( $fh, $ret ) if defined wantarray;
3783 } ## end if ($doret eq $stack_depth...
3785 # Return the appropriate scalar value.
3787 } ## end else [ if (wantarray)
3790 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
3792 In Perl 5.8.0, there was a major realignment of the commands and what they did,
3793 Most of the changes were to systematize the command structure and to eliminate
3794 commands that threw away user input without checking.
3796 The following sections describe the code added to make it easy to support
3797 multiple command sets with conflicting command names. This section is a start
3798 at unifying all command processing to make it simpler to develop commands.
3800 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
3801 number, and C<$dbline> (the current line) as arguments.
3803 Support functions in this section which have multiple modes of failure C<die>
3804 on error; the rest simply return a false value.
3806 The user-interface functions (all of the C<cmd_*> functions) just output
3811 The C<%set> hash defines the mapping from command letter to subroutine
3814 C<%set> is a two-level hash, indexed by set name and then by command name.
3815 Note that trying to set the CommandSet to C<foobar> simply results in the
3816 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
3825 'A' => 'pre580_null',
3827 'B' => 'pre580_null',
3828 'd' => 'pre580_null',
3831 'M' => 'pre580_null',
3833 'o' => 'pre580_null',
3839 '<' => 'pre590_prepost',
3840 '<<' => 'pre590_prepost',
3841 '>' => 'pre590_prepost',
3842 '>>' => 'pre590_prepost',
3843 '{' => 'pre590_prepost',
3844 '{{' => 'pre590_prepost',
3848 =head2 C<cmd_wrapper()> (API)
3850 C<cmd_wrapper()> allows the debugger to switch command sets
3851 depending on the value of the C<CommandSet> option.
3853 It tries to look up the command in the C<%set> package-level I<lexical>
3854 (which means external entities can't fiddle with it) and create the name of
3855 the sub to call based on the value found in the hash (if it's there). I<All>
3856 of the commands to be handled in a set have to be added to C<%set>; if they
3857 aren't found, the 5.8.0 equivalent is called (if there is one).
3859 This code uses symbolic references.
3866 my $dblineno = shift;
3868 # Assemble the command subroutine's name by looking up the
3869 # command set and command name in %set. If we can't find it,
3870 # default to the older version of the command.
3872 . ( $set{$CommandSet}{$cmd}
3873 || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) );
3875 # Call the command subroutine, call it by name.
3876 return &$call( $cmd, $line, $dblineno );
3877 } ## end sub cmd_wrapper
3879 =head3 C<cmd_a> (command)
3881 The C<a> command handles pre-execution actions. These are associated with a
3882 particular line, so they're stored in C<%dbline>. We default to the current
3883 line if none is specified.
3889 my $line = shift || ''; # [.|line] expr
3892 # If it's dot (here), or not all digits, use the current line.
3893 $line =~ s/^(\.|(?:[^\d]))/$dbline/;
3895 # Should be a line number followed by an expression.
3896 if ( $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
3897 my ( $lineno, $expr ) = ( $1, $2 );
3899 # If we have an expression ...
3900 if ( length $expr ) {
3902 # ... but the line isn't breakable, complain.
3903 if ( $dbline[$lineno] == 0 ) {
3905 "Line $lineno($dbline[$lineno]) does not have an action?\n";
3909 # It's executable. Record that the line has an action.
3910 $had_breakpoints{$filename} |= 2;
3912 # Remove any action, temp breakpoint, etc.
3913 $dbline{$lineno} =~ s/\0[^\0]*//;
3915 # Add the action to the line.
3916 $dbline{$lineno} .= "\0" . action($expr);
3918 } ## end if (length $expr)
3919 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
3924 "Adding an action requires an optional lineno and an expression\n"
3929 =head3 C<cmd_A> (command)
3931 Delete actions. Similar to above, except the delete code is in a separate
3932 subroutine, C<delete_action>.
3938 my $line = shift || '';
3942 $line =~ s/^\./$dbline/;
3944 # Call delete_action with a null param to delete them all.
3945 # The '1' forces the eval to be true. It'll be false only
3946 # if delete_action blows up for some reason, in which case
3947 # we print $@ and get out.
3948 if ( $line eq '*' ) {
3949 eval { &delete_action(); 1 } or print $OUT $@ and return;
3952 # There's a real line number. Pass it to delete_action.
3953 # Error trapping is as above.
3954 elsif ( $line =~ /^(\S.*)/ ) {
3955 eval { &delete_action($1); 1 } or print $OUT $@ and return;
3958 # Swing and a miss. Bad syntax.
3961 "Deleting an action requires a line number, or '*' for all\n" ; # hint
3965 =head3 C<delete_action> (API)
3967 C<delete_action> accepts either a line number or C<undef>. If a line number
3968 is specified, we check for the line being executable (if it's not, it
3969 couldn't have had an action). If it is, we just take the action off (this
3970 will get any kind of an action, including breakpoints).
3976 if ( defined($i) ) {
3979 die "Line $i has no action .\n" if $dbline[$i] == 0;
3981 # Nuke whatever's there.
3982 $dbline{$i} =~ s/\0[^\0]*//; # \^a
3983 delete $dbline{$i} if $dbline{$i} eq '';
3986 print $OUT "Deleting all actions...\n";
3987 for my $file ( keys %had_breakpoints ) {
3988 local *dbline = $main::{ '_<' . $file };
3991 for ( $i = 1 ; $i <= $max ; $i++ ) {
3992 if ( defined $dbline{$i} ) {
3993 $dbline{$i} =~ s/\0[^\0]*//;
3994 delete $dbline{$i} if $dbline{$i} eq '';
3996 unless ( $had_breakpoints{$file} &= ~2 ) {
3997 delete $had_breakpoints{$file};
3999 } ## end for ($i = 1 ; $i <= $max...
4000 } ## end for my $file (keys %had_breakpoints)
4001 } ## end else [ if (defined($i))
4002 } ## end sub delete_action
4004 =head3 C<cmd_b> (command)
4006 Set breakpoints. Since breakpoints can be set in so many places, in so many
4007 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4008 we try to parse the command type, and then shuttle it off to an appropriate
4009 subroutine to actually do the work of setting the breakpoint in the right
4016 my $line = shift; # [.|line] [cond]
4019 # Make . the current line number if it's there..
4020 $line =~ s/^\./$dbline/;
4022 # No line number, no condition. Simple break on current line.
4023 if ( $line =~ /^\s*$/ ) {
4024 &cmd_b_line( $dbline, 1 );
4027 # Break on load for a file.
4028 elsif ( $line =~ /^load\b\s*(.*)/ ) {
4034 # b compile|postpone <some sub> [<condition>]
4035 # The interpreter actually traps this one for us; we just put the
4036 # necessary condition in the %postponed hash.
4037 elsif ( $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4039 # Capture the condition if there is one. Make it true if none.
4040 my $cond = length $3 ? $3 : '1';
4042 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
4043 # if it was 'compile'.
4044 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
4046 # De-Perl4-ify the name - ' separators to ::.
4047 $subname =~ s/\'/::/g;
4049 # Qualify it into the current package unless it's already qualified.
4050 $subname = "${'package'}::" . $subname unless $subname =~ /::/;
4052 # Add main if it starts with ::.
4053 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4055 # Save the break type for this sub.
4056 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
4057 } ## end elsif ($line =~ ...
4059 # b <sub name> [<condition>]
4060 elsif ( $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4064 $cond = length $2 ? $2 : '1';
4065 &cmd_b_sub( $subname, $cond );
4068 # b <line> [<condition>].
4069 elsif ( $line =~ /^(\d*)\s*(.*)/ ) {
4071 # Capture the line. If none, it's the current line.
4072 $line = $1 || $dbline;
4074 # If there's no condition, make it '1'.
4075 $cond = length $2 ? $2 : '1';
4078 &cmd_b_line( $line, $cond );
4081 # Line didn't make sense.
4083 print "confused by line($line)?\n";
4087 =head3 C<break_on_load> (API)
4089 We want to break when this file is loaded. Mark this file in the
4090 C<%break_on_load> hash, and note that it has a breakpoint in
4091 C<%had_breakpoints>.
4097 $break_on_load{$file} = 1;
4098 $had_breakpoints{$file} |= 1;
4101 =head3 C<report_break_on_load> (API)
4103 Gives us an array of filenames that are set to break on load. Note that
4104 only files with break-on-load are in here, so simply showing the keys
4109 sub report_break_on_load {
4110 sort keys %break_on_load;
4113 =head3 C<cmd_b_load> (command)
4115 We take the file passed in and try to find it in C<%INC> (which maps modules
4116 to files they came from). We mark those files for break-on-load via
4117 C<break_on_load> and then report that it was done.
4125 # This is a block because that way we can use a redo inside it
4126 # even without there being any looping structure at all outside it.
4129 # Save short name and full path if found.
4131 push @files, $::INC{$file} if $::INC{$file};
4133 # Tack on .pm and do it again unless there was a '.' in the name
4135 $file .= '.pm', redo unless $file =~ /\./;
4138 # Do the real work here.
4139 break_on_load($_) for @files;
4141 # All the files that have break-on-load breakpoints.
4142 @files = report_break_on_load;
4144 # Normalize for the purposes of our printing this.
4147 print $OUT "Will stop on load of `@files'.\n";
4148 } ## end sub cmd_b_load
4150 =head3 C<$filename_error> (API package global)
4152 Several of the functions we need to implement in the API need to work both
4153 on the current file and on other files. We don't want to duplicate code, so
4154 C<$filename_error> is used to contain the name of the file that's being
4155 worked on (if it's not the current one).
4157 We can now build functions in pairs: the basic function works on the current
4158 file, and uses C<$filename_error> as part of its error message. Since this is
4159 initialized to C<"">, no filename will appear when we are working on the
4162 The second function is a wrapper which does the following:
4168 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4172 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4176 Calls the first function.
4178 The first function works on the I<current> file (i.e., the one we changed to),
4179 and prints C<$filename_error> in the error message (the name of the other file)
4180 if it needs to. When the functions return, C<*dbline> is restored to point
4181 to the actual current file (the one we're executing in) and
4182 C<$filename_error> is restored to C<"">. This restores everything to
4183 the way it was before the second function was called at all.
4185 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4192 $filename_error = '';
4194 =head3 breakable_line(from, to) (API)
4196 The subroutine decides whether or not a line in the current file is breakable.
4197 It walks through C<@dbline> within the range of lines specified, looking for
4198 the first line that is breakable.
4200 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4201 first line I<after> C<$to> that's breakable, if there is one.
4203 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4204 first line I<before> C<$to> that's breakable, if there is one.
4208 sub breakable_line {
4210 my ( $from, $to ) = @_;
4212 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4215 # If there are at least 2 arguments, we're trying to search a range.
4218 # $delta is positive for a forward search, negative for a backward one.
4219 my $delta = $from < $to ? +1 : -1;
4221 # Keep us from running off the ends of the file.
4222 my $limit = $delta > 0 ? $#dbline : 1;
4224 # Clever test. If you're a mathematician, it's obvious why this
4225 # test works. If not:
4226 # If $delta is positive (going forward), $limit will be $#dbline.
4227 # If $to is less than $limit, ($limit - $to) will be positive, times
4228 # $delta of 1 (positive), so the result is > 0 and we should use $to
4229 # as the stopping point.
4231 # If $to is greater than $limit, ($limit - $to) is negative,
4232 # times $delta of 1 (positive), so the result is < 0 and we should
4233 # use $limit ($#dbline) as the stopping point.
4235 # If $delta is negative (going backward), $limit will be 1.
4236 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4237 # (negative) so the result is > 0, and we use $to as the stopping
4240 # If $to is less than zero, ($limit - $to) will be positive,
4241 # times $delta of -1 (negative), so the result is not > 0, and
4242 # we use $limit (1) as the stopping point.
4244 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4245 # (negative), still giving zero; the result is not > 0, and
4246 # we use $limit (1) as the stopping point.
4248 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4249 # (negative), giving a positive (>0) value, so we'll set $limit to
4252 $limit = $to if ( $limit - $to ) * $delta > 0;
4254 # The real search loop.
4255 # $i starts at $from (the point we want to start searching from).
4256 # We move through @dbline in the appropriate direction (determined
4257 # by $delta: either -1 (back) or +1 (ahead).
4258 # We stay in as long as we haven't hit an executable line
4259 # ($dbline[$i] == 0 means not executable) and we haven't reached
4260 # the limit yet (test similar to the above).
4261 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4263 } ## end if (@_ >= 2)
4265 # If $i points to a line that is executable, return that.
4266 return $i unless $dbline[$i] == 0;
4268 # Format the message and print it: no breakable lines in range.
4269 my ( $pl, $upto ) = ( '', '' );
4270 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4272 # If there's a filename in filename_error, we'll see it.
4274 die "Line$pl $from$upto$filename_error not breakable\n";
4275 } ## end sub breakable_line
4277 =head3 breakable_line_in_filename(file, from, to) (API)
4279 Like C<breakable_line>, but look in another file.
4283 sub breakable_line_in_filename {
4285 # Capture the file name.
4288 # Swap the magic line array over there temporarily.
4289 local *dbline = $main::{ '_<' . $f };
4291 # If there's an error, it's in this other file.
4292 local $filename_error = " of `$f'";
4294 # Find the breakable line.
4297 # *dbline and $filename_error get restored when this block ends.
4299 } ## end sub breakable_line_in_filename
4301 =head3 break_on_line(lineno, [condition]) (API)
4303 Adds a breakpoint with the specified condition (or 1 if no condition was
4304 specified) to the specified line. Dies if it can't.
4309 my ( $i, $cond ) = @_;
4311 # Always true if no condition supplied.
4312 $cond = 1 unless @_ >= 2;
4318 # Woops, not a breakable line. $filename_error allows us to say
4319 # if it was in a different file.
4320 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4322 # Mark this file as having breakpoints in it.
4323 $had_breakpoints{$filename} |= 1;
4325 # If there is an action or condition here already ...
4326 if ( $dbline{$i} ) {
4328 # ... swap this condition for the existing one.
4329 $dbline{$i} =~ s/^[^\0]*/$cond/;
4333 # Nothing here - just add the condition.
4334 $dbline{$i} = $cond;
4336 } ## end sub break_on_line
4338 =head3 cmd_b_line(line, [condition]) (command)
4340 Wrapper for C<break_on_line>. Prints the failure message if it
4346 eval { break_on_line(@_); 1 } or do {
4348 print $OUT $@ and return;
4350 } ## end sub cmd_b_line
4352 =head3 break_on_filename_line(file, line, [condition]) (API)
4354 Switches to the file specified and then calls C<break_on_line> to set
4359 sub break_on_filename_line {
4360 my ( $f, $i, $cond ) = @_;
4362 # Always true if condition left off.
4363 $cond = 1 unless @_ >= 3;
4365 # Switch the magical hash temporarily.
4366 local *dbline = $main::{ '_<' . $f };
4368 # Localize the variables that break_on_line uses to make its message.
4369 local $filename_error = " of `$f'";
4370 local $filename = $f;
4372 # Add the breakpoint.
4373 break_on_line( $i, $cond );
4374 } ## end sub break_on_filename_line
4376 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4378 Switch to another file, search the range of lines specified for an
4379 executable one, and put a breakpoint on the first one you find.
4383 sub break_on_filename_line_range {
4384 my ( $f, $from, $to, $cond ) = @_;
4386 # Find a breakable line if there is one.
4387 my $i = breakable_line_in_filename( $f, $from, $to );
4389 # Always true if missing.
4390 $cond = 1 unless @_ >= 3;
4392 # Add the breakpoint.
4393 break_on_filename_line( $f, $i, $cond );
4394 } ## end sub break_on_filename_line_range
4396 =head3 subroutine_filename_lines(subname, [condition]) (API)
4398 Search for a subroutine within a given file. The condition is ignored.
4399 Uses C<find_sub> to locate the desired subroutine.
4403 sub subroutine_filename_lines {
4404 my ( $subname, $cond ) = @_;
4406 # Returned value from find_sub() is fullpathname:startline-endline.
4407 # The match creates the list (fullpathname, start, end). Falling off
4408 # the end of the subroutine returns this implicitly.
4409 find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/;
4410 } ## end sub subroutine_filename_lines
4412 =head3 break_subroutine(subname) (API)
4414 Places a break on the first line possible in the specified subroutine. Uses
4415 C<subroutine_filename_lines> to find the subroutine, and
4416 C<break_on_filename_line_range> to place the break.
4420 sub break_subroutine {
4421 my $subname = shift;
4423 # Get filename, start, and end.
4424 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
4425 or die "Subroutine $subname not found.\n";
4427 # Null condition changes to '1' (always true).
4428 $cond = 1 unless @_ >= 2;
4430 # Put a break the first place possible in the range of lines
4431 # that make up this subroutine.
4432 break_on_filename_line_range( $file, $s, $e, @_ );
4433 } ## end sub break_subroutine
4435 =head3 cmd_b_sub(subname, [condition]) (command)
4437 We take the incoming subroutine name and fully-qualify it as best we can.
4441 =item 1. If it's already fully-qualified, leave it alone.
4443 =item 2. Try putting it in the current package.
4445 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
4447 =item 4. If it starts with '::', put it in 'main::'.
4451 After all this cleanup, we call C<break_subroutine> to try to set the
4457 my ( $subname, $cond ) = @_;
4459 # Add always-true condition if we have none.
4460 $cond = 1 unless @_ >= 2;
4462 # If the subname isn't a code reference, qualify it so that
4463 # break_subroutine() will work right.
4464 unless ( ref $subname eq 'CODE' ) {
4467 $subname =~ s/\'/::/g;
4470 # Put it in this package unless it's already qualified.
4471 $subname = "${'package'}::" . $subname
4472 unless $subname =~ /::/;
4474 # Requalify it into CORE::GLOBAL if qualifying it into this
4475 # package resulted in its not being defined, but only do so
4476 # if it really is in CORE::GLOBAL.
4477 $subname = "CORE::GLOBAL::$s"
4478 if not defined &$subname
4480 and defined &{"CORE::GLOBAL::$s"};
4482 # Put it in package 'main' if it has a leading ::.
4483 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4485 } ## end unless (ref $subname eq 'CODE')
4487 # Try to set the breakpoint.
4488 eval { break_subroutine( $subname, $cond ); 1 } or do {
4490 print $OUT $@ and return;
4492 } ## end sub cmd_b_sub
4494 =head3 C<cmd_B> - delete breakpoint(s) (command)
4496 The command mostly parses the command line and tries to turn the argument
4497 into a line spec. If it can't, it uses the current line. It then calls
4498 C<delete_breakpoint> to actually do the work.
4500 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
4501 thereby deleting all the breakpoints.
4508 # No line spec? Use dbline.
4509 # If there is one, use it if it's non-zero, or wipe it out if it is.
4510 my $line = ( $_[0] =~ /^\./ ) ? $dbline : shift || '';
4513 # If the line was dot, make the line the current one.
4514 $line =~ s/^\./$dbline/;
4516 # If it's * we're deleting all the breakpoints.
4517 if ( $line eq '*' ) {
4518 eval { &delete_breakpoint(); 1 } or print $OUT $@ and return;
4521 # If there is a line spec, delete the breakpoint on that line.
4522 elsif ( $line =~ /^(\S.*)/ ) {
4523 eval { &delete_breakpoint( $line || $dbline ); 1 } or do {
4525 print $OUT $@ and return;
4527 } ## end elsif ($line =~ /^(\S.*)/)
4532 "Deleting a breakpoint requires a line number, or '*' for all\n"
4537 =head3 delete_breakpoint([line]) (API)
4539 This actually does the work of deleting either a single breakpoint, or all
4542 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
4543 just drop out with a message saying so. If it is, we remove the condition
4544 part of the 'condition\0action' that says there's a breakpoint here. If,
4545 after we've done that, there's nothing left, we delete the corresponding
4546 line in C<%dbline> to signal that no action needs to be taken for this line.
4548 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
4549 which lists all currently-loaded files which have breakpoints. We then look
4550 at each line in each of these files, temporarily switching the C<%dbline>
4551 and C<@dbline> structures to point to the files in question, and do what
4552 we did in the single line case: delete the condition in C<@dbline>, and
4553 delete the key in C<%dbline> if nothing's left.
4555 We then wholesale delete C<%postponed>, C<%postponed_file>, and
4556 C<%break_on_load>, because these structures contain breakpoints for files
4557 and code that haven't been loaded yet. We can just kill these off because there
4558 are no magical debugger structures associated with them.
4562 sub delete_breakpoint {
4565 # If we got a line, delete just that one.
4566 if ( defined($i) ) {
4568 # Woops. This line wasn't breakable at all.
4569 die "Line $i not breakable.\n" if $dbline[$i] == 0;
4571 # Kill the condition, but leave any action.
4572 $dbline{$i} =~ s/^[^\0]*//;
4574 # Remove the entry entirely if there's no action left.
4575 delete $dbline{$i} if $dbline{$i} eq '';
4578 # No line; delete them all.
4580 print $OUT "Deleting all breakpoints...\n";
4582 # %had_breakpoints lists every file that had at least one
4584 for my $file ( keys %had_breakpoints ) {
4586 # Switch to the desired file temporarily.
4587 local *dbline = $main::{ '_<' . $file };
4592 # For all lines in this file ...
4593 for ( $i = 1 ; $i <= $max ; $i++ ) {
4595 # If there's a breakpoint or action on this line ...
4596 if ( defined $dbline{$i} ) {
4598 # ... remove the breakpoint.
4599 $dbline{$i} =~ s/^[^\0]+//;
4600 if ( $dbline{$i} =~ s/^\0?$// ) {
4602 # Remove the entry altogether if no action is there.
4605 } ## end if (defined $dbline{$i...
4606 } ## end for ($i = 1 ; $i <= $max...
4608 # If, after we turn off the "there were breakpoints in this file"
4609 # bit, the entry in %had_breakpoints for this file is zero,
4610 # we should remove this file from the hash.
4611 if ( not $had_breakpoints{$file} &= ~1 ) {
4612 delete $had_breakpoints{$file};
4614 } ## end for my $file (keys %had_breakpoints)
4616 # Kill off all the other breakpoints that are waiting for files that
4617 # haven't been loaded yet.
4619 undef %postponed_file;
4620 undef %break_on_load;
4621 } ## end else [ if (defined($i))
4622 } ## end sub delete_breakpoint
4624 =head3 cmd_stop (command)
4626 This is meant to be part of the new command API, but it isn't called or used
4627 anywhere else in the debugger. XXX It is probably meant for use in development
4632 sub cmd_stop { # As on ^C, but not signal-safy.
4636 =head3 C<cmd_e> - threads
4638 Display the current thread id:
4642 This could be how (when implemented) to send commands to this thread id (e cmd)
4643 or that thread id (e tid cmd).
4650 unless (exists($INC{'threads.pm'})) {
4651 print "threads not loaded($ENV{PERL5DB_THREADED})
4652 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4654 my $tid = threads->self->tid;
4655 print "thread id: $tid\n";
4659 =head3 C<cmd_E> - list of thread ids
4661 Display the list of available thread ids:
4665 This could be used (when implemented) to send commands to all threads (E cmd).
4672 unless (exists($INC{'threads.pm'})) {
4673 print "threads not loaded($ENV{PERL5DB_THREADED})
4674 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4676 my $tid = threads->self->tid;
4677 print "thread ids: ".join(', ',
4678 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
4683 =head3 C<cmd_h> - help command (command)
4685 Does the work of either
4691 Showing all the debugger help
4695 Showing help for a specific command
4704 # If we have no operand, assume null.
4705 my $line = shift || '';
4707 # 'h h'. Print the long-format help.
4708 if ( $line =~ /^h\s*/ ) {
4712 # 'h <something>'. Search for the command and print only its help.
4713 elsif ( $line =~ /^(\S.*)$/ ) {
4715 # support long commands; otherwise bogus errors
4716 # happen when you ask for h on <CR> for example
4717 my $asked = $1; # the command requested
4718 # (for proper error message)
4720 my $qasked = quotemeta($asked); # for searching; we don't
4721 # want to use it as a pattern.
4722 # XXX: finds CR but not <CR>
4724 # Search the help string for the command.
4726 $help =~ /^ # Start of a line
4728 (?:[IB]<) # Optional markup
4729 $qasked # The requested command
4734 # It's there; pull it out and print it.
4738 (?:[IB]<) # Optional markup
4739 $qasked # The command
4740 ([\s\S]*?) # Description line(s)
4741 \n) # End of last description line
4742 (?!\s) # Next line not starting with
4751 # Not found; not a debugger command.
4753 print_help("B<$asked> is not a debugger command.\n");
4755 } ## end elsif ($line =~ /^(\S.*)$/)
4757 # 'h' - print the summary help.
4759 print_help($summary);
4763 =head3 C<cmd_i> - inheritance display
4765 Display the (nested) parentage of the module or object given.
4772 eval { require Class::ISA };
4774 &warn( $@ =~ /locate/
4775 ? "Class::ISA module not found - please install\n"
4780 foreach my $isa ( split( /\s+/, $line ) ) {
4786 map { # snaffled unceremoniously from Class::ISA
4789 defined( ${"$_\::VERSION"} )
4790 ? ' ' . ${"$_\::VERSION"}
4792 } Class::ISA::self_and_super_path(ref($isa) || $isa)
4799 =head3 C<cmd_l> - list lines (command)
4801 Most of the command is taken up with transforming all the different line
4802 specification syntaxes into 'start-stop'. After that is done, the command
4803 runs a loop over C<@dbline> for the specified range of lines. It handles
4804 the printing of each line and any markers (C<==E<gt>> for current line,
4805 C<b> for break on this line, C<a> for action on this line, C<:> for this
4808 We save the last line listed in the C<$start> global for further listing
4814 my $current_line = $line;
4818 # If this is '-something', delete any spaces after the dash.
4819 $line =~ s/^-\s*$/-/;
4821 # If the line is '$something', assume this is a scalar containing a
4823 if ( $line =~ /^(\$.*)/s ) {
4825 # Set up for DB::eval() - evaluate in *user* context.
4830 # Ooops. Bad scalar.
4831 print( $OUT "Error: $@\n" ), next CMD if $@;
4833 # Good scalar. If it's a reference, find what it points to.
4835 print( $OUT "Interpreted as: $1 $s\n" );
4838 # Call self recursively to really do the command.
4840 } ## end if ($line =~ /^(\$.*)/s)
4842 # l name. Try to find a sub by that name.
4843 elsif ( $line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s ) {
4844 my $s = $subname = $1;
4847 $subname =~ s/\'/::/;
4849 # Put it in this package unless it starts with ::.
4850 $subname = $package . "::" . $subname unless $subname =~ /::/;
4852 # Put it in CORE::GLOBAL if t doesn't start with :: and
4853 # it doesn't live in this package and it lives in CORE::GLOBAL.
4854 $subname = "CORE::GLOBAL::$s"
4855 if not defined &$subname
4857 and defined &{"CORE::GLOBAL::$s"};
4859 # Put leading '::' names into 'main::'.
4860 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4862 # Get name:start-stop from find_sub, and break this up at
4864 @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
4866 # Pull off start-stop.
4867 $subrange = pop @pieces;
4869 # If the name contained colons, the split broke it up.
4870 # Put it back together.
4871 $file = join( ':', @pieces );
4873 # If we're not in that file, switch over to it.
4874 if ( $file ne $filename ) {
4875 print $OUT "Switching to file '$file'.\n"
4876 unless $slave_editor;
4878 # Switch debugger's magic structures.
4879 *dbline = $main::{ '_<' . $file };
4882 } ## end if ($file ne $filename)
4884 # Subrange is 'start-stop'. If this is less than a window full,
4885 # swap it to 'start+', which will list a window from the start point.
4887 if ( eval($subrange) < -$window ) {
4888 $subrange =~ s/-.*/+/;
4891 # Call self recursively to list the range.
4893 &cmd_l( 'l', $subrange );
4894 } ## end if ($subrange)
4898 print $OUT "Subroutine $subname not found.\n";
4900 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
4903 elsif ( $line =~ /^\s*$/ ) {
4905 # Compute new range to list.
4906 $incr = $window - 1;
4907 $line = $start . '-' . ( $start + $incr );
4910 &cmd_l( 'l', $line );
4913 # l [start]+number_of_lines
4914 elsif ( $line =~ /^(\d*)\+(\d*)$/ ) {
4916 # Don't reset start for 'l +nnn'.
4919 # Increment for list. Use window size if not specified.
4920 # (Allows 'l +' to work.)
4922 $incr = $window - 1 unless $incr;
4924 # Create a line range we'll understand, and recurse to do it.
4925 $line = $start . '-' . ( $start + $incr );
4926 &cmd_l( 'l', $line );
4927 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
4929 # l start-stop or l start,stop
4930 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) {
4932 # Determine end point; use end of file if not specified.
4933 $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 );
4935 # Go on to the end, and then stop.
4936 $end = $max if $end > $max;
4938 # Determine start line.
4940 $i = $line if $i eq '.';
4944 # If we're running under a slave editor, force it to show the lines.
4945 if ($slave_editor) {
4946 print $OUT "\032\032$filename:$i:0\n";
4950 # We're doing it ourselves. We want to show the line and special
4952 # - the current line in execution
4953 # - whether a line is breakable or not
4954 # - whether a line has a break or not
4955 # - whether a line has an action or not
4957 for ( ; $i <= $end ; $i++ ) {
4959 # Check for breakpoints and actions.
4960 my ( $stop, $action );
4961 ( $stop, $action ) = split( /\0/, $dbline{$i} )
4964 # ==> if this is the current line in execution,
4965 # : if it's breakable.
4967 ( $i == $current_line and $filename eq $filename_ini )
4969 : ( $dbline[$i] + 0 ? ':' : ' ' );
4971 # Add break and action indicators.
4972 $arrow .= 'b' if $stop;
4973 $arrow .= 'a' if $action;
4976 print $OUT "$i$arrow\t", $dbline[$i];
4978 # Move on to the next line. Drop out on an interrupt.
4979 $i++, last if $signal;
4980 } ## end for (; $i <= $end ; $i++)
4982 # Line the prompt up; print a newline if the last line listed
4983 # didn't have a newline.
4984 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/;
4985 } ## end else [ if ($slave_editor)
4987 # Save the point we last listed to in case another relative 'l'
4988 # command is desired. Don't let it run off the end.
4990 $start = $max if $start > $max;
4991 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
4994 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
4996 To list breakpoints, the command has to look determine where all of them are
4997 first. It starts a C<%had_breakpoints>, which tells us what all files have
4998 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
4999 magic source and breakpoint data structures) to the file, and then look
5000 through C<%dbline> for lines with breakpoints and/or actions, listing them
5001 out. We look through C<%postponed> not-yet-compiled subroutines that have
5002 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5003 that have breakpoints.
5005 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5012 # If no argument, list everything. Pre-5.8.0 version always lists
5014 my $arg = shift || 'abw';
5015 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
5017 # See what is wanted.
5018 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0;
5019 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0;
5020 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0;
5022 # Breaks and actions are found together, so we look in the same place
5024 if ( $break_wanted or $action_wanted ) {
5026 # Look in all the files with breakpoints...
5027 for my $file ( keys %had_breakpoints ) {
5029 # Temporary switch to this file.
5030 local *dbline = $main::{ '_<' . $file };
5032 # Set up to look through the whole file.
5034 my $was; # Flag: did we print something
5037 # For each line in the file ...
5038 for ( $i = 1 ; $i <= $max ; $i++ ) {
5040 # We've got something on this line.
5041 if ( defined $dbline{$i} ) {
5043 # Print the header if we haven't.
5044 print $OUT "$file:\n" unless $was++;
5047 print $OUT " $i:\t", $dbline[$i];
5049 # Pull out the condition and the action.
5050 ( $stop, $action ) = split( /\0/, $dbline{$i} );
5052 # Print the break if there is one and it's wanted.
5053 print $OUT " break if (", $stop, ")\n"
5057 # Print the action if there is one and it's wanted.
5058 print $OUT " action: ", $action, "\n"
5062 # Quit if the user hit interrupt.
5064 } ## end if (defined $dbline{$i...
5065 } ## end for ($i = 1 ; $i <= $max...
5066 } ## end for my $file (keys %had_breakpoints)
5067 } ## end if ($break_wanted or $action_wanted)
5069 # Look for breaks in not-yet-compiled subs:
5070 if ( %postponed and $break_wanted ) {
5071 print $OUT "Postponed breakpoints in subroutines:\n";
5073 for $subname ( keys %postponed ) {
5074 print $OUT " $subname\t$postponed{$subname}\n";
5077 } ## end if (%postponed and $break_wanted)
5079 # Find files that have not-yet-loaded breaks:
5080 my @have = map { # Combined keys
5081 keys %{ $postponed_file{$_} }
5082 } keys %postponed_file;
5084 # If there are any, list them.
5085 if ( @have and ( $break_wanted or $action_wanted ) ) {
5086 print $OUT "Postponed breakpoints in files:\n";
5087 my ( $file, $line );
5089 for $file ( keys %postponed_file ) {
5090 my $db = $postponed_file{$file};
5091 print $OUT " $file:\n";
5092 for $line ( sort { $a <=> $b } keys %$db ) {
5093 print $OUT " $line:\n";
5094 my ( $stop, $action ) = split( /\0/, $$db{$line} );
5095 print $OUT " break if (", $stop, ")\n"
5098 print $OUT " action: ", $action, "\n"
5102 } ## end for $line (sort { $a <=>...
5104 } ## end for $file (keys %postponed_file)
5105 } ## end if (@have and ($break_wanted...
5106 if ( %break_on_load and $break_wanted ) {
5107 print $OUT "Breakpoints on load:\n";
5109 for $file ( keys %break_on_load ) {
5110 print $OUT " $file\n";
5113 } ## end if (%break_on_load and...
5114 if ($watch_wanted) {
5116 print $OUT "Watch-expressions:\n" if @to_watch;
5117 for my $expr (@to_watch) {
5118 print $OUT " $expr\n";
5121 } ## end if ($trace & 2)
5122 } ## end if ($watch_wanted)
5125 =head3 C<cmd_M> - list modules (command)
5127 Just call C<list_modules>.
5135 =head3 C<cmd_o> - options (command)
5137 If this is just C<o> by itself, we list the current settings via
5138 C<dump_option>. If there's a nonblank value following it, we pass that on to
5139 C<parse_options> for processing.
5145 my $opt = shift || ''; # opt[=val]
5147 # Nonblank. Try to parse and process.
5148 if ( $opt =~ /^(\S.*)/ ) {
5152 # Blank. List the current option settings.
5160 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5162 Advises the user that the O command has been renamed.
5167 print $OUT "The old O command is now the o command.\n"; # hint
5168 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5169 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5172 =head3 C<cmd_v> - view window (command)
5174 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5175 move back a few lines to list the selected line in context. Uses C<cmd_l>
5176 to do the actual listing after figuring out the range of line to request.
5184 # Extract the line to list around. (Astute readers will have noted that
5185 # this pattern will match whether or not a numeric line is specified,
5186 # which means that we'll always enter this loop (though a non-numeric
5187 # argument results in no action at all)).
5188 if ( $line =~ /^(\d*)$/ ) {
5190 # Total number of lines to list (a windowful).
5191 $incr = $window - 1;
5193 # Set the start to the argument given (if there was one).
5196 # Back up by the context amount.
5199 # Put together a linespec that cmd_l will like.
5200 $line = $start . '-' . ( $start + $incr );
5203 &cmd_l( 'l', $line );
5204 } ## end if ($line =~ /^(\d*)$/)
5207 =head3 C<cmd_w> - add a watch expression (command)
5209 The 5.8 version of this command adds a watch expression if one is specified;
5210 it does nothing if entered with no operands.
5212 We extract the expression, save it, evaluate it in the user's context, and
5213 save the value. We'll re-evaluate it each time the debugger passes a line,
5214 and will stop (see the code at the top of the command loop) if the value
5215 of any of the expressions changes.
5222 # Null expression if no arguments.
5223 my $expr = shift || '';
5225 # If expression is not null ...
5226 if ( $expr =~ /^(\S.*)/ ) {
5229 push @to_watch, $expr;
5231 # Parameterize DB::eval and call it to get the expression's value
5232 # in the user's context. This version can handle expressions which
5233 # return a list value.
5235 my ($val) = join( ' ', &eval );
5236 $val = ( defined $val ) ? "'$val'" : 'undef';
5238 # Save the current value of the expression.
5239 push @old_watch, $val;
5241 # We are now watching expressions.
5243 } ## end if ($expr =~ /^(\S.*)/)
5245 # You have to give one to get one.
5247 print $OUT "Adding a watch-expression requires an expression\n"; # hint
5251 =head3 C<cmd_W> - delete watch expressions (command)
5253 This command accepts either a watch expression to be removed from the list
5254 of watch expressions, or C<*> to delete them all.
5256 If C<*> is specified, we simply empty the watch expression list and the
5257 watch expression value list. We also turn off the bit that says we've got
5260 If an expression (or partial expression) is specified, we pattern-match
5261 through the expressions and remove the ones that match. We also discard
5262 the corresponding values. If no watch expressions are left, we turn off
5263 the I<watching expressions> bit.
5269 my $expr = shift || '';
5272 if ( $expr eq '*' ) {
5277 print $OUT "Deleting all watch expressions ...\n";
5280 @to_watch = @old_watch = ();
5283 # Delete one of them.
5284 elsif ( $expr =~ /^(\S.*)/ ) {
5286 # Where we are in the list.
5289 # For each expression ...
5290 foreach (@to_watch) {
5291 my $val = $to_watch[$i_cnt];
5293 # Does this one match the command argument?
5294 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
5295 # Yes. Turn it off, and its value too.
5296 splice( @to_watch, $i_cnt, 1 );
5297 splice( @old_watch, $i_cnt, 1 );
5300 } ## end foreach (@to_watch)
5302 # We don't bother to turn watching off because
5303 # a) we don't want to stop calling watchfunction() it it exists
5304 # b) foreach over a null list doesn't do anything anyway
5306 } ## end elsif ($expr =~ /^(\S.*)/)
5308 # No command arguments entered.
5311 "Deleting a watch-expression requires an expression, or '*' for all\n"
5316 ### END of the API section
5318 =head1 SUPPORT ROUTINES
5320 These are general support routines that are used in a number of places
5321 throughout the debugger.
5327 Something to do with assertions
5334 unless ($ini_assertion) {
5335 print $OUT "Assertions not supported in this Perl interpreter\n";
5337 if ( $cmd =~ /^.\b\s*([+-]?)\s*(~?)\s*(\w+(\s*\|\s*\w+)*)\s*$/ ) {
5338 my ( $how, $neg, $flags ) = ( $1, $2, $3 );
5339 my $acu = parse_DollarCaretP_flags($flags);
5340 if ( defined $acu ) {
5341 $acu = ~$acu if $neg;
5342 if ( $how eq '+' ) { $^P |= $acu }
5343 elsif ( $how eq '-' ) { $^P &= ~$acu }
5347 # else { print $OUT "undefined acu\n" }
5349 my $expanded = expand_DollarCaretP_flags($^P);
5350 print $OUT "Internal Perl debugger flags:\n\$^P=$expanded\n";
5357 save() saves the user's versions of globals that would mess us up in C<@saved>,
5358 and installs the versions we like better.
5364 # Save eval failure, command failure, extended OS error, output field
5365 # separator, input record separator, output record separator and
5366 # the warning setting.
5367 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
5369 $, = ""; # output field separator is null string
5370 $/ = "\n"; # input record separator is newline
5371 $\ = ""; # output record separator is null string
5372 $^W = 0; # warnings are off
5375 =head2 C<print_lineinfo> - show where we are now
5377 print_lineinfo prints whatever it is that it is handed; it prints it to the
5378 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5379 us to feed line information to a slave editor without messing up the
5384 sub print_lineinfo {
5386 # Make the terminal sensible if we're not the primary debugger.
5387 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5391 } ## end sub print_lineinfo
5393 =head2 C<postponed_sub>
5395 Handles setting postponed breakpoints in subroutines once they're compiled.
5396 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5397 range for the subroutine, then mark the file as having a breakpoint,
5398 temporarily switch the C<*dbline> glob over to the source file, and then
5399 search the given range of lines to find a breakable line. If we find one,
5400 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
5404 # The following takes its argument via $evalarg to preserve current @_
5408 # Get the subroutine name.
5409 my $subname = shift;
5411 # If this is a 'break +<n> if <condition>' ...
5412 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
5414 # If there's no offset, use '+0'.
5415 my $offset = $1 || 0;
5417 # find_sub's value is 'fullpath-filename:start-stop'. It's
5418 # possible that the filename might have colons in it too.
5419 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
5422 # We got the start line. Add the offset '+<n>' from
5423 # $postponed{subname}.
5426 # Switch to the file this sub is in, temporarily.
5427 local *dbline = $main::{ '_<' . $file };
5429 # No warnings, please.
5430 local $^W = 0; # != 0 is magical below
5432 # This file's got a breakpoint in it.
5433 $had_breakpoints{$file} |= 1;
5435 # Last line in file.
5438 # Search forward until we hit a breakable line or get to
5439 # the end of the file.
5440 ++$i until $dbline[$i] != 0 or $i >= $max;
5442 # Copy the breakpoint in and delete it from %postponed.
5443 $dbline{$i} = delete $postponed{$subname};
5446 # find_sub didn't find the sub.
5449 print $OUT "Subroutine $subname not found.\n";
5452 } ## end if ($postponed{$subname...
5453 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
5455 #print $OUT "In postponed_sub for `$subname'.\n";
5456 } ## end sub postponed_sub
5460 Called after each required file is compiled, but before it is executed;
5461 also called if the name of a just-compiled subroutine is a key of
5462 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
5463 etc.) into the just-compiled code.
5465 If this is a C<require>'d file, the incoming parameter is the glob
5466 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
5468 If it's a subroutine, the incoming parameter is the subroutine name.
5474 # If there's a break, process it.
5475 if ($ImmediateStop) {
5477 # Right, we've stopped. Turn it off.
5480 # Enter the command loop when DB::DB gets called.
5484 # If this is a subroutine, let postponed_sub() deal with it.
5485 return &postponed_sub unless ref \$_[0] eq 'GLOB';
5487 # Not a subroutine. Deal with the file.
5488 local *dbline = shift;
5489 my $filename = $dbline;
5490 $filename =~ s/^_<//;
5492 $signal = 1, print $OUT "'$filename' loaded...\n"
5493 if $break_on_load{$filename};
5494 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
5496 # Do we have any breakpoints to put in this file?
5497 return unless $postponed_file{$filename};
5499 # Yes. Mark this file as having breakpoints.
5500 $had_breakpoints{$filename} |= 1;
5502 # "Cannot be done: unsufficient magic" - we can't just put the
5503 # breakpoints saved in %postponed_file into %dbline by assigning
5504 # the whole hash; we have to do it one item at a time for the
5505 # breakpoints to be set properly.
5506 #%dbline = %{$postponed_file{$filename}};
5508 # Set the breakpoints, one at a time.
5511 for $key ( keys %{ $postponed_file{$filename} } ) {
5513 # Stash the saved breakpoint into the current file's magic line array.
5514 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
5517 # This file's been compiled; discard the stored breakpoints.
5518 delete $postponed_file{$filename};
5520 } ## end sub postponed
5524 C<dumpit> is the debugger's wrapper around dumpvar.pl.
5526 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
5527 a reference to a variable (the thing to be dumped) as its input.
5529 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
5530 the currently-selected filehandle, thank you very much). The current
5531 values of the package globals C<$single> and C<$trace> are backed up in
5532 lexicals, and they are turned off (this keeps the debugger from trying
5533 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
5534 preserve its current value and it is set to zero to prevent entry/exit
5535 messages from printing, and C<$doret> is localized as well and set to -2 to
5536 prevent return values from being shown.
5538 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
5539 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
5540 installed version in C<@INC>, yours will be used instead. Possible security
5543 It then checks to see if the subroutine C<main::dumpValue> is now defined
5544 (it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
5545 localizes the globals necessary for things to be sane when C<main::dumpValue()>
5546 is called, and picks up the variable to be dumped from the parameter list.
5548 It checks the package global C<%options> to see if there's a C<dumpDepth>
5549 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
5550 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
5551 structure: -1 means dump everything.
5553 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
5556 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
5557 and we then return to the caller.
5563 # Save the current output filehandle and switch to the one
5564 # passed in as the first parameter.
5565 local ($savout) = select(shift);
5567 # Save current settings of $single and $trace, and then turn them off.
5568 my $osingle = $single;
5569 my $otrace = $trace;
5570 $single = $trace = 0;
5572 # XXX Okay, what do $frame and $doret do, again?
5576 # Load dumpvar.pl unless we've already got the sub we need from it.
5577 unless ( defined &main::dumpValue ) {
5581 # If the load succeeded (or we already had dumpvalue()), go ahead
5583 if ( defined &main::dumpValue ) {
5588 my $maxdepth = shift || $option{dumpDepth};
5589 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
5590 &main::dumpValue( $v, $maxdepth );
5591 } ## end if (defined &main::dumpValue)
5593 # Oops, couldn't load dumpvar.pl.
5596 print $OUT "dumpvar.pl not available.\n";
5599 # Reset $single and $trace to their old values.
5603 # Restore the old filehandle.
5607 =head2 C<print_trace>
5609 C<print_trace>'s job is to print a stack trace. It does this via the
5610 C<dump_trace> routine, which actually does all the ferreting-out of the
5611 stack trace data. C<print_trace> takes care of formatting it nicely and
5612 printing it to the proper filehandle.
5620 The filehandle to print to.
5624 How many frames to skip before starting trace.
5628 How many frames to print.
5632 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
5636 The original comment below seems to be noting that the traceback may not be
5637 correct if this routine is called in a tied method.
5641 # Tied method do not create a context, so may get wrong message:
5647 # If this is going to a slave editor, but we're not the primary
5648 # debugger, reset it first.
5650 if $fh eq $LINEINFO # slave editor
5651 and $LINEINFO eq $OUT # normal output
5652 and $term_pid != $$; # not the primary
5654 # Collect the actual trace information to be formatted.
5655 # This is an array of hashes of subroutine call info.
5656 my @sub = dump_trace( $_[0] + 1, $_[1] );
5658 # Grab the "short report" flag from @_.
5659 my $short = $_[2]; # Print short report, next one for sub name
5661 # Run through the traceback info, format it, and print it.
5663 for ( $i = 0 ; $i <= $#sub ; $i++ ) {
5665 # Drop out if the user has lost interest and hit control-C.
5668 # Set the separator so arrys print nice.
5671 # Grab and stringify the arguments if they are there.
5673 defined $sub[$i]{args}
5674 ? "(@{ $sub[$i]{args} })"
5677 # Shorten them up if $maxtrace says they're too long.
5678 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
5679 if length $args > $maxtrace;
5681 # Get the file name.
5682 my $file = $sub[$i]{file};
5684 # Put in a filename header if short is off.
5685 $file = $file eq '-e' ? $file : "file `$file'" unless $short;
5687 # Get the actual sub's name, and shorten to $maxtrace's requirement.
5689 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
5691 # Short report uses trimmed file and sub names.
5693 my $sub = @_ >= 4 ? $_[3] : $s;
5694 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
5695 } ## end if ($short)
5697 # Non-short report includes full names.
5699 print $fh "$sub[$i]{context} = $s$args"
5700 . " called from $file"
5701 . " line $sub[$i]{line}\n";
5703 } ## end for ($i = 0 ; $i <= $#sub...
5704 } ## end sub print_trace
5706 =head2 dump_trace(skip[,count])
5708 Actually collect the traceback information available via C<caller()>. It does
5709 some filtering and cleanup of the data, but mostly it just collects it to
5710 make C<print_trace()>'s job easier.
5712 C<skip> defines the number of stack frames to be skipped, working backwards
5713 from the most current. C<count> determines the total number of frames to
5714 be returned; all of them (well, the first 10^9) are returned if C<count>
5717 This routine returns a list of hashes, from most-recent to least-recent
5718 stack frame. Each has the following keys and values:
5722 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
5724 =item * C<sub> - subroutine name, or C<eval> information
5726 =item * C<args> - undef, or a reference to an array of arguments
5728 =item * C<file> - the file in which this item was defined (if any)
5730 =item * C<line> - the line on which it was defined
5738 # How many levels to skip.
5741 # How many levels to show. (1e9 is a cheap way of saying "all of them";
5742 # it's unlikely that we'll have more than a billion stack frames. If you
5743 # do, you've got an awfully big machine...)
5744 my $count = shift || 1e9;
5746 # We increment skip because caller(1) is the first level *back* from
5747 # the current one. Add $skip to the count of frames so we have a
5748 # simple stop criterion, counting from $skip to $count+$skip.
5752 # These variables are used to capture output from caller();
5753 my ( $p, $file, $line, $sub, $h, $context );
5755 my ( $e, $r, @a, @sub, $args );
5757 # XXX Okay... why'd we do that?
5758 my $nothard = not $frame & 8;
5761 # Do not want to trace this.
5762 my $otrace = $trace;
5765 # Start out at the skip count.
5766 # If we haven't reached the number of frames requested, and caller() is
5767 # still returning something, stay in the loop. (If we pass the requested
5768 # number of stack frames, or we run out - caller() returns nothing - we
5770 # Up the stack frame index to go back one more level each time.
5774 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
5779 # Go through the arguments and save them for later.
5783 if ( not defined $arg ) { # undefined parameter
5787 elsif ( $nothard and tied $arg ) { # tied parameter
5790 elsif ( $nothard and $type = ref $arg ) { # reference
5791 push @a, "ref($type)";
5793 else { # can be stringified
5795 "$arg"; # Safe to stringify now - should not call f().
5797 # Backslash any single-quotes or backslashes.
5800 # Single-quote it unless it's a number or a colon-separated
5803 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
5805 # Turn high-bit characters into meta-whatever.
5806 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
5808 # Turn control characters into ^-whatever.
5809 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
5812 } ## end else [ if (not defined $arg)
5813 } ## end for $arg (@args)
5815 # If context is true, this is array (@)context.
5816 # If context is false, this is scalar ($) context.
5817 # If neither, context isn't defined. (This is apparently a 'can't
5819 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
5821 # if the sub has args ($h true), make an anonymous array of the
5823 $args = $h ? [@a] : undef;
5825 # remove trailing newline-whitespace-semicolon-end of line sequence
5826 # from the eval text, if any.
5827 $e =~ s/\n\s*\;\s*\Z// if $e;
5829 # Escape backslashed single-quotes again if necessary.
5830 $e =~ s/([\\\'])/\\$1/g if $e;
5832 # if the require flag is true, the eval text is from a require.
5834 $sub = "require '$e'";
5837 # if it's false, the eval text is really from an eval.
5838 elsif ( defined $r ) {
5842 # If the sub is '(eval)', this is a block eval, meaning we don't
5843 # know what the eval'ed text actually was.
5844 elsif ( $sub eq '(eval)' ) {
5845 $sub = "eval {...}";
5848 # Stick the collected information into @sub as an anonymous hash.
5852 context => $context,
5860 # Stop processing frames if the user hit control-C.
5862 } ## end for ($i = $skip ; $i < ...
5864 # Restore the trace value again.
5867 } ## end sub dump_trace
5871 C<action()> takes input provided as the argument to an add-action command,
5872 either pre- or post-, and makes sure it's a complete command. It doesn't do
5873 any fancy parsing; it just keeps reading input until it gets a string
5874 without a trailing backslash.
5881 while ( $action =~ s/\\$// ) {
5883 # We have a backslash on the end. Read more.
5885 } ## end while ($action =~ s/\\$//)
5887 # Return the assembled action.
5893 This routine mostly just packages up a regular expression to be used
5894 to check that the thing it's being matched against has properly-matched
5897 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
5898 speeds things up by only creating the qr//'ed expression once; if it's
5899 already defined, we don't try to define it again. A speed hack.
5905 # I hate using globals!
5906 $balanced_brace_re ||= qr{
5909 (?> [^{}] + ) # Non-parens without backtracking
5911 (??{ $balanced_brace_re }) # Group with matching parens
5915 return $_[0] !~ m/$balanced_brace_re/;
5916 } ## end sub unbalanced
5920 C<gets()> is a primitive (very primitive) routine to read continuations.
5921 It was devised for reading continuations for actions.
5922 it just reads more input with C<readline()> and returns it.
5927 &readline("cont: ");
5930 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger
5932 The C<system()> function assumes that it can just go ahead and use STDIN and
5933 STDOUT, but under the debugger, we want it to use the debugger's input and
5936 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes
5937 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
5938 and then puts everything back again.
5944 # We save, change, then restore STDIN and STDOUT to avoid fork() since
5945 # some non-Unix systems can do system() but have problems with fork().
5946 open( SAVEIN, "<&STDIN" ) || &warn("Can't save STDIN");
5947 open( SAVEOUT, ">&STDOUT" ) || &warn("Can't save STDOUT");
5948 open( STDIN, "<&IN" ) || &warn("Can't redirect STDIN");
5949 open( STDOUT, ">&OUT" ) || &warn("Can't redirect STDOUT");
5951 # XXX: using csh or tcsh destroys sigint retvals!
5953 open( STDIN, "<&SAVEIN" ) || &warn("Can't restore STDIN");
5954 open( STDOUT, ">&SAVEOUT" ) || &warn("Can't restore STDOUT");
5958 # most of the $? crud was coping with broken cshisms
5960 &warn( "(Command exited ", ( $? >> 8 ), ")\n" );
5964 "(Command died of SIG#",
5966 ( ( $? & 128 ) ? " -- core dumped" : "" ),
5975 =head1 TTY MANAGEMENT
5977 The subs here do some of the terminal management for multiple debuggers.
5981 Top-level function called when we want to set up a new terminal for use
5984 If the C<noTTY> debugger option was set, we'll either use the terminal
5985 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
5986 to find one. If we're a forked debugger, we call C<resetterm> to try to
5987 get a whole new terminal if we can.
5989 In either case, we set up the terminal next. If the C<ReadLine> option was
5990 true, we'll get a C<Term::ReadLine> object for the current terminal and save
5991 the appropriate attributes. We then
5997 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6000 eval { require Term::ReadLine } or die $@;
6002 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6005 my ( $i, $o ) = split $tty, /,/;
6006 $o = $i unless defined $o;
6007 open( IN, "<$i" ) or die "Cannot open TTY `$i' for read: $!";
6008 open( OUT, ">$o" ) or die "Cannot open TTY `$o' for write: $!";
6011 my $sel = select($OUT);
6016 # We don't have a TTY - try to find one via Term::Rendezvous.
6018 eval "require Term::Rendezvous;" or die;
6020 # See if we have anything to pass to Term::Rendezvous.
6021 # Use $HOME/.perldbtty$$ if not.
6022 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6024 # Rendezvous and get the filehandles.
6025 my $term_rv = new Term::Rendezvous $rv;
6027 $OUT = $term_rv->OUT;
6028 } ## end else [ if ($tty)
6029 } ## end if ($notty)
6031 # We're a daughter debugger. Try to fork off another TTY.
6032 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6036 # If we shouldn't use Term::ReadLine, don't.
6038 $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT;
6041 # We're using Term::ReadLine. Get all the attributes for this terminal.
6043 $term = new Term::ReadLine 'perldb', $IN, $OUT;
6045 $rl_attribs = $term->Attribs;
6046 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6047 if defined $rl_attribs->{basic_word_break_characters}
6048 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6049 $rl_attribs->{special_prefixes} = '$@&%';
6050 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6051 $rl_attribs->{completion_function} = \&db_complete;
6052 } ## end else [ if (!$rl)
6054 # Set up the LINEINFO filehandle.
6055 $LINEINFO = $OUT unless defined $LINEINFO;
6056 $lineinfo = $console unless defined $lineinfo;
6060 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6061 $term->SetHistory(@hist);
6064 # XXX Ornaments are turned on unconditionally, which is not
6065 # always a good thing.
6066 ornaments($ornaments) if defined $ornaments;
6068 } ## end sub setterm
6070 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6072 When the process being debugged forks, or the process invokes a command
6073 via C<system()> which starts a new debugger, we need to be able to get a new
6074 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6075 fight over the terminal, and you can never quite be sure who's going to get the
6076 input you're typing.
6078 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6079 is tasked with doing all the necessary operating system mojo to get a new
6080 TTY (and probably another window) and to direct the new debugger to read and
6083 The debugger provides C<get_fork_TTY> functions which work for X Windows and
6084 OS/2. Other systems are not supported. You are encouraged to write
6085 C<get_fork_TTY> functions which work for I<your> platform and contribute them.
6087 =head3 C<xterm_get_fork_TTY>
6089 This function provides the C<get_fork_TTY> function for X windows. If a
6090 program running under the debugger forks, a new <xterm> window is opened and
6091 the subsidiary debugger is directed there.
6093 The C<open()> call is of particular note here. We have the new C<xterm>
6094 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6095 command (which prints the device name of the TTY we'll want to use for input
6096 and output to STDOUT, then C<sleep> for a very long time, routing this output
6097 to file number 3. This way we can simply read from the <XT> filehandle (which
6098 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6100 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6105 sub xterm_get_fork_TTY {
6106 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6108 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6111 # Get the output from 'tty' and clean it up a little.
6115 $pidprompt = ''; # Shown anyway in titlebar
6117 # There's our new TTY.
6119 } ## end sub xterm_get_fork_TTY
6121 =head3 C<os2_get_fork_TTY>
6123 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6127 # This example function resets $IN, $OUT itself
6128 sub os2_get_fork_TTY {
6129 local $^F = 40; # XXXX Fixme!
6131 my ( $in1, $out1, $in2, $out2 );
6133 # Having -d in PERL5OPT would lead to a disaster...
6134 local $ENV{PERL5OPT} = $ENV{PERL5OPT} if $ENV{PERL5OPT};
6135 $ENV{PERL5OPT} =~ s/(?:^|(?<=\s))-d\b// if $ENV{PERL5OPT};
6136 $ENV{PERL5OPT} =~ s/(?:^|(?<=\s))-d\B/-/ if $ENV{PERL5OPT};
6137 print $OUT "Making kid PERL5OPT->`$ENV{PERL5OPT}'.\n" if $ENV{PERL5OPT};
6138 local $ENV{PERL5LIB} = $ENV{PERL5LIB} ? $ENV{PERL5LIB} : $ENV{PERLLIB};
6139 $ENV{PERL5LIB} = '' unless defined $ENV{PERL5LIB};
6140 $ENV{PERL5LIB} = join ';', @ini_INC, split /;/, $ENV{PERL5LIB};
6141 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6146 and pipe $in2, $out2
6148 # system P_SESSION will fail if there is another process
6149 # in the same session with a "dependent" asynchronous child session.
6151 $rl, fileno $in1, fileno $out2, "Daughter Perl debugger $pids $name"
6154 ( $kpid = CORE::system 4, $^X, '-we',
6155 <<'ES', @args ) >= 0 # P_SESSION
6156 END {sleep 5 unless $loaded}
6157 BEGIN {open STDIN, '</dev/con' or warn "reopen stdin: $!"}
6160 my ($rl, $in) = (shift, shift); # Read from $in and pass through
6162 system P_NOWAIT, $^X, '-we', <<EOS or die "Cannot start a grandkid";
6163 open IN, '<&=$in' or die "open <&=$in: \$!";
6164 \$| = 1; print while sysread IN, \$_, 1<<16;
6168 open OUT, ">&=$out" or die "Cannot open &=$out for writing: $!";
6170 require Term::ReadKey if $rl;
6171 Term::ReadKey::ReadMode(4) if $rl; # Nodelay on kbd. Pipe is automatically nodelay...
6172 print while sysread STDIN, $_, 1<<($rl ? 16 : 0);
6174 or warn "system P_SESSION: $!, $^E" and 0
6180 $pidprompt = ''; # Shown anyway in titlebar
6181 reset_IN_OUT( $in2, $out1 );
6183 return ''; # Indicate that reset_IN_OUT is called
6184 } ## end if (pipe $in1, $out1 and...
6186 } ## end sub os2_get_fork_TTY
6188 =head2 C<create_IN_OUT($flags)>
6190 Create a new pair of filehandles, pointing to a new TTY. If impossible,
6191 try to diagnose why.
6197 =item * 1 - Don't know how to create a new TTY.
6199 =item * 2 - Debugger has forked, but we can't get a new TTY.
6201 =item * 4 - standard debugger startup is happening.
6207 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
6209 # If we know how to get a new TTY, do it! $in will have
6210 # the TTY name if get_fork_TTY works.
6211 my $in = &get_fork_TTY if defined &get_fork_TTY;
6213 # It used to be that
6214 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
6216 if ( not defined $in ) {
6219 # We don't know how.
6220 print_help(<<EOP) if $why == 1;
6221 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6225 print_help(<<EOP) if $why == 2;
6226 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6227 This may be an asynchronous session, so the parent debugger may be active.
6230 # Note that both debuggers are fighting over the same input.
6231 print_help(<<EOP) if $why != 4;
6232 Since two debuggers fight for the same TTY, input is severely entangled.
6236 I know how to switch the output to a different window in xterms
6237 and OS/2 consoles only. For a manual switch, put the name of the created I<TTY>
6238 in B<\$DB::fork_TTY>, or define a function B<DB::get_fork_TTY()> returning this.
6240 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6241 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6244 } ## end if (not defined $in)
6245 elsif ( $in ne '' ) {
6249 $console = ''; # Indicate no need to open-from-the-console
6252 } ## end sub create_IN_OUT
6256 Handles rejiggering the prompt when we've forked off a new debugger.
6258 If the new debugger happened because of a C<system()> that invoked a
6259 program under the debugger, the arrow between the old pid and the new
6260 in the prompt has I<two> dashes instead of one.
6262 We take the current list of pids and add this one to the end. If there
6263 isn't any list yet, we make one up out of the initial pid associated with
6264 the terminal and our new pid, sticking an arrow (either one-dashed or
6265 two dashed) in between them.
6267 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6268 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6273 sub resetterm { # We forked, so we need a different TTY
6275 # Needs to be passed to create_IN_OUT() as well.
6278 # resetterm(2): got in here because of a system() starting a debugger.
6279 # resetterm(1): just forked.
6280 my $systemed = $in > 1 ? '-' : '';
6282 # If there's already a list of pids, add this to the end.
6284 $pids =~ s/\]/$systemed->$$]/;
6287 # No pid list. Time to make one.
6289 $pids = "[$term_pid->$$]";
6292 # The prompt we're going to be using for this debugger.
6295 # We now 0wnz this terminal.
6298 # Just return if we're not supposed to try to create a new TTY.
6299 return unless $CreateTTY & $in;
6301 # Try to create a new IN/OUT pair.
6303 } ## end sub resetterm
6307 First, we handle stuff in the typeahead buffer. If there is any, we shift off
6308 the next line, print a message saying we got it, add it to the terminal
6309 history (if possible), and return it.
6311 If there's nothing in the typeahead buffer, check the command filehandle stack.
6312 If there are any filehandles there, read from the last one, and return the line
6313 if we got one. If not, we pop the filehandle off and close it, and try the
6314 next one up the stack.
6316 If we've emptied the filehandle stack, we check to see if we've got a socket
6317 open, and we read that and return it if we do. If we don't, we just call the
6318 core C<readline()> and return its value.
6324 # Localize to prevent it from being smashed in the program being debugged.
6327 # Pull a line out of the typeahead if there's stuff there.
6330 # How many lines left.
6331 my $left = @typeahead;
6333 # Get the next line.
6334 my $got = shift @typeahead;
6336 # Print a message saying we got input from the typeahead.
6338 print $OUT "auto(-$left)", shift, $got, "\n";
6340 # Add it to the terminal history (if possible).
6341 $term->AddHistory($got)
6343 and defined $term->Features->{addHistory};
6345 } ## end if (@typeahead)
6347 # We really need to read some input. Turn off entry/exit trace and
6348 # return value printing.
6352 # If there are stacked filehandles to read from ...
6355 # Read from the last one in the stack.
6356 my $line = CORE::readline( $cmdfhs[-1] );
6358 # If we got a line ...
6360 ? ( print $OUT ">> $line" and return $line ) # Echo and return
6361 : close pop @cmdfhs; # Pop and close
6362 } ## end while (@cmdfhs)
6364 # Nothing on the filehandle stack. Socket?
6365 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
6367 # Send anyting we have to send.
6368 $OUT->write( join( '', @_ ) );
6370 # Receive anything there is to receive.
6375 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
6376 # XXX Don't know. You tell me.
6377 } while length $buf and ($stuff .= $buf) !~ /\n/;
6381 } ## end if (ref $OUT and UNIVERSAL::isa...
6383 # No socket. Just read from the terminal.
6385 $term->readline(@_);
6387 } ## end sub readline
6389 =head1 OPTIONS SUPPORT ROUTINES
6391 These routines handle listing and setting option values.
6393 =head2 C<dump_option> - list the current value of an option setting
6395 This routine uses C<option_val> to look up the value for an option.
6396 It cleans up escaped single-quotes and then displays the option and
6402 my ( $opt, $val ) = @_;
6403 $val = option_val( $opt, 'N/A' );
6404 $val =~ s/([\\\'])/\\$1/g;
6405 printf $OUT "%20s = '%s'\n", $opt, $val;
6406 } ## end sub dump_option
6408 sub options2remember {
6409 foreach my $k (@RememberOnROptions) {
6410 $option{$k} = option_val( $k, 'N/A' );
6415 =head2 C<option_val> - find the current value of an option
6417 This can't just be a simple hash lookup because of the indirect way that
6418 the option values are stored. Some are retrieved by calling a subroutine,
6419 some are just variables.
6421 You must supply a default value to be used in case the option isn't set.
6426 my ( $opt, $default ) = @_;
6429 # Does this option exist, and is it a variable?
6430 # If so, retrieve the value via the value in %optionVars.
6431 if ( defined $optionVars{$opt}
6432 and defined ${ $optionVars{$opt} } )
6434 $val = ${ $optionVars{$opt} };
6437 # Does this option exist, and it's a subroutine?
6438 # If so, call the subroutine via the ref in %optionAction
6439 # and capture the value.
6440 elsif ( defined $optionAction{$opt}
6441 and defined &{ $optionAction{$opt} } )
6443 $val = &{ $optionAction{$opt} }();
6446 # If there's an action or variable for the supplied option,
6447 # but no value was set, use the default.
6448 elsif (defined $optionAction{$opt} and not defined $option{$opt}
6449 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
6454 # Otherwise, do the simple hash lookup.
6456 $val = $option{$opt};
6459 # If the value isn't defined, use the default.
6460 # Then return whatever the value is.
6461 $val = $default unless defined $val;
6463 } ## end sub option_val
6465 =head2 C<parse_options>
6467 Handles the parsing and execution of option setting/displaying commands.
6469 An option entered by itself is assumed to be I<set me to 1> (the default value)
6470 if the option is a boolean one. If not, the user is prompted to enter a valid
6471 value or to query the current value (via C<option? >).
6473 If C<option=value> is entered, we try to extract a quoted string from the
6474 value (if it is quoted). If it's not, we just use the whole value as-is.
6476 We load any modules required to service this option, and then we set it: if
6477 it just gets stuck in a variable, we do that; if there's a subroutine to
6478 handle setting the option, we call that.
6480 Finally, if we're running in interactive mode, we display the effect of the
6481 user's command back to the terminal, skipping this if we're setting things
6482 during initialization.
6490 # These options need a value. Don't allow them to be clobbered by accident.
6491 my %opt_needs_val = map { ( $_ => 1 ) } qw{
6492 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
6493 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
6499 # Clean off excess leading whitespace.
6502 # Options are always all word characters, followed by a non-word
6504 s/^(\w+)(\W?)// or print( $OUT "Invalid option `$_'\n" ), last;
6505 my ( $opt, $sep ) = ( $1, $2 );
6507 # Make sure that such an option exists.
6508 my $matches = grep( /^\Q$opt/ && ( $option = $_ ), @options )
6509 || grep( /^\Q$opt/i && ( $option = $_ ), @options );
6511 print( $OUT "Unknown option `$opt'\n" ), next unless $matches;
6512 print( $OUT "Ambiguous option `$opt'\n" ), next if $matches > 1;
6515 # '?' as separator means query, but must have whitespace after it.
6516 if ( "?" eq $sep ) {
6517 print( $OUT "Option query `$opt?' followed by non-space `$_'\n" ),
6521 #&dump_option($opt);
6522 } ## end if ("?" eq $sep)
6524 # Separator is whitespace (or just a carriage return).
6525 # They're going for a default, which we assume is 1.
6526 elsif ( $sep !~ /\S/ ) {
6528 $val = "1"; # this is an evil default; make 'em set it!
6531 # Separator is =. Trying to set a value.
6532 elsif ( $sep eq "=" ) {
6534 # If quoted, extract a quoted string.
6535 if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
6537 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
6540 # Not quoted. Use the whole thing. Warn about 'option='.
6544 print OUT qq(Option better cleared using $opt=""\n)
6546 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
6548 } ## end elsif ($sep eq "=")
6550 # "Quoted" with [], <>, or {}.
6551 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
6553 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
6554 s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
6555 or print( $OUT "Unclosed option value `$opt$sep$_'\n" ), last;
6556 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
6557 } ## end else [ if ("?" eq $sep)
6559 # Exclude non-booleans from getting set to 1 by default.
6560 if ( $opt_needs_val{$option} && $val_defaulted ) {
6561 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
6563 "Option `$opt' is non-boolean. Use `$cmd $option=VAL' to set, `$cmd $option?' to query\n";
6565 } ## end if ($opt_needs_val{$option...
6567 # Save the option value.
6568 $option{$option} = $val if defined $val;
6570 # Load any module that this option requires.
6574 require '$optionRequire{$option}';
6576 } || die # XXX: shouldn't happen
6577 if defined $optionRequire{$option}
6581 # Stick it in the proper variable if it goes in a variable.
6582 ${ $optionVars{$option} } = $val
6583 if defined $optionVars{$option}
6586 # Call the appropriate sub if it gets set via sub.
6587 &{ $optionAction{$option} }($val)
6588 if defined $optionAction{$option}
6589 && defined &{ $optionAction{$option} }
6592 # Not initialization - echo the value we set it to.
6593 dump_option($option) unless $OUT eq \*STDERR;
6594 } ## end while (length)
6595 } ## end sub parse_options
6597 =head1 RESTART SUPPORT
6599 These routines are used to store (and restore) lists of items in environment
6600 variables during a restart.
6604 Set_list packages up items to be stored in a set of environment variables
6605 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
6606 the values). Values outside the standard ASCII charset are stored by encoding
6607 then as hexadecimal values.
6612 my ( $stem, @list ) = @_;
6615 # VAR_n: how many we have. Scalar assignment gets the number of items.
6616 $ENV{"${stem}_n"} = @list;
6618 # Grab each item in the list, escape the backslashes, encode the non-ASCII
6619 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
6620 for $i ( 0 .. $#list ) {
6622 $val =~ s/\\/\\\\/g;
6623 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
6624 $ENV{"${stem}_$i"} = $val;
6625 } ## end for $i (0 .. $#list)
6626 } ## end sub set_list
6630 Reverse the set_list operation: grab VAR_n to see how many we should be getting
6631 back, and then pull VAR_0, VAR_1. etc. back out.
6638 my $n = delete $ENV{"${stem}_n"};
6640 for $i ( 0 .. $n - 1 ) {
6641 $val = delete $ENV{"${stem}_$i"};
6642 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
6646 } ## end sub get_list
6648 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
6652 The C<catch()> subroutine is the essence of fast and low-impact. We simply
6653 set an already-existing global scalar variable to a constant value. This
6654 avoids allocating any memory possibly in the middle of something that will
6655 get all confused if we do, particularly under I<unsafe signals>.
6661 return; # Put nothing on the stack - malloc/free land!
6666 C<warn> emits a warning, by joining together its arguments and printing
6667 them, with couple of fillips.
6669 If the composited message I<doesn't> end with a newline, we automatically
6670 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
6671 to be set to the filehandle to be used to output warnings; it makes no
6672 assumptions about what filehandles are available.
6677 my ($msg) = join( "", @_ );
6678 $msg .= ": $!\n" unless $msg =~ /\n$/;
6683 =head1 INITIALIZATION TTY SUPPORT
6685 =head2 C<reset_IN_OUT>
6687 This routine handles restoring the debugger's input and output filehandles
6688 after we've tried and failed to move them elsewhere. In addition, it assigns
6689 the debugger's output filehandle to $LINEINFO if it was already open there.
6694 my $switch_li = $LINEINFO eq $OUT;
6696 # If there's a term and it's able to get a new tty, try to get one.
6697 if ( $term and $term->Features->{newTTY} ) {
6698 ( $IN, $OUT ) = ( shift, shift );
6699 $term->newTTY( $IN, $OUT );
6702 # This term can't get a new tty now. Better luck later.
6704 &warn("Too late to set IN/OUT filehandles, enabled on next `R'!\n");
6707 # Set the filehndles up as they were.
6709 ( $IN, $OUT ) = ( shift, shift );
6712 # Unbuffer the output filehandle.
6713 my $o = select $OUT;
6717 # Point LINEINFO to the same output filehandle if it was there before.
6718 $LINEINFO = $OUT if $switch_li;
6719 } ## end sub reset_IN_OUT
6721 =head1 OPTION SUPPORT ROUTINES
6723 The following routines are used to process some of the more complicated
6728 Sets the input and output filehandles to the specified files or pipes.
6729 If the terminal supports switching, we go ahead and do it. If not, and
6730 there's already a terminal in place, we save the information to take effect
6733 If there's no terminal yet (for instance, during debugger initialization),
6734 we go ahead and set C<$console> and C<$tty> to the file indicated.
6740 # With VMS we can get here with $term undefined, so we do not
6741 # switch to this terminal. There may be a better place to make
6742 # sure that $term is defined on VMS
6743 if ( @_ and ($^O eq 'VMS') and !defined($term) ) {
6744 eval { require Term::ReadLine } or die $@;
6746 $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT;
6749 $term = new Term::ReadLine 'perldb', $IN, $OUT;
6752 if ( @_ and $term and $term->Features->{newTTY} ) {
6754 # This terminal supports switching to a new TTY.
6755 # Can be a list of two files, or on string containing both names,
6757 # XXX Should this perhaps be an assignment from @_?
6758 my ( $in, $out ) = shift;
6761 # Split list apart if supplied.
6762 ( $in, $out ) = split /,/, $in, 2;
6766 # Use the same file for both input and output.
6770 # Open file onto the debugger's filehandles, if you can.
6771 open IN, $in or die "cannot open `$in' for read: $!";
6772 open OUT, ">$out" or die "cannot open `$out' for write: $!";
6774 # Swap to the new filehandles.
6775 reset_IN_OUT( \*IN, \*OUT );
6777 # Save the setting for later.
6779 } ## end if (@_ and $term and $term...
6781 # Terminal doesn't support new TTY, or doesn't support readline.
6782 # Can't do it now, try restarting.
6783 &warn("Too late to set TTY, enabled on next `R'!\n") if $term and @_;
6785 # Useful if done through PERLDB_OPTS:
6786 $console = $tty = shift if @_;
6788 # Return whatever the TTY is.
6794 Sets the C<$notty> global, controlling whether or not the debugger tries to
6795 get a terminal to read from. If called after a terminal is already in place,
6796 we save the value to use it if we're restarted.
6802 &warn("Too late to set noTTY, enabled on next `R'!\n") if @_;
6804 $notty = shift if @_;
6810 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
6811 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
6812 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
6813 the value in case a restart is done so we can change it then.
6819 &warn("Too late to set ReadLine, enabled on next `R'!\n") if @_;
6823 } ## end sub ReadLine
6825 =head2 C<RemotePort>
6827 Sets the port that the debugger will try to connect to when starting up.
6828 If the terminal's already been set up, we can't do it, but we remember the
6829 setting in case the user does a restart.
6835 &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
6837 $remoteport = shift if @_;
6839 } ## end sub RemotePort
6843 Checks with the terminal to see if C<Tk> is running, and returns true or
6844 false. Returns false if the current terminal doesn't support C<readline>.
6849 if ( ${ $term->Features }{tkRunning} ) {
6850 return $term->tkRunning(@_);
6854 print $OUT "tkRunning not supported by current ReadLine package.\n";
6857 } ## end sub tkRunning
6861 Sets nonstop mode. If a terminal's already been set up, it's too late; the
6862 debugger remembers the setting in case you restart, though.
6868 &warn("Too late to set up NonStop mode, enabled on next `R'!\n")
6871 $runnonstop = shift if @_;
6873 } ## end sub NonStop
6877 &warn("Some flag changes could not take effect until next 'R'!\n")
6880 $^P = parse_DollarCaretP_flags(shift) if @_;
6881 expand_DollarCaretP_flags($^P);
6884 sub OnlyAssertions {
6886 &warn("Too late to set up OnlyAssertions mode, enabled on next 'R'!\n")
6890 unless ( defined $ini_assertion ) {
6892 &warn("Current Perl interpreter doesn't support assertions");
6897 unless ($ini_assertion) {
6898 print "Assertions will be active on next 'R'!\n";
6901 $^P &= ~$DollarCaretP_flags{PERLDBf_SUB};
6902 $^P |= $DollarCaretP_flags{PERLDBf_ASSERTION};
6905 $^P |= $DollarCaretP_flags{PERLDBf_SUB};
6908 !( $^P & $DollarCaretP_flags{PERLDBf_SUB} ) || 0;
6913 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
6921 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
6928 Sets the shell escape command, and generates a printable copy to be used
6935 # If we got an argument, meta-quote it, and add '\b' if it
6936 # ends in a word character.
6938 $sh = quotemeta shift;
6939 $sh .= "\\b" if $sh =~ /\w$/;
6942 # Generate the printable version for the help:
6943 $psh = $sh; # copy it
6944 $psh =~ s/\\b$//; # Take off trailing \b if any
6945 $psh =~ s/\\(.)/$1/g; # De-escape
6946 $psh; # return the printable version
6947 } ## end sub shellBang
6951 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
6952 was passed as the argument. (This means you can't override the terminal's
6958 if ( defined $term ) {
6960 # We don't want to show warning backtraces, but we do want die() ones.
6961 local ( $warnLevel, $dieLevel ) = ( 0, 1 );
6963 # No ornaments if the terminal doesn't support them.
6964 return '' unless $term->Features->{ornaments};
6965 eval { $term->ornaments(@_) } || '';
6968 # Use what was passed in if we can't determine it ourselves.
6972 } ## end sub ornaments
6974 =head2 C<recallCommand>
6976 Sets the recall command, and builds a printable version which will appear in
6983 # If there is input, metaquote it. Add '\b' if it ends with a word
6986 $rc = quotemeta shift;
6987 $rc .= "\\b" if $rc =~ /\w$/;
6990 # Build it into a printable version.
6991 $prc = $rc; # Copy it
6992 $prc =~ s/\\b$//; # Remove trailing \b
6993 $prc =~ s/\\(.)/$1/g; # Remove escapes
6994 $prc; # Return the printable version
6995 } ## end sub recallCommand
6997 =head2 C<LineInfo> - where the line number information goes
6999 Called with no arguments, returns the file or pipe that line info should go to.
7001 Called with an argument (a file or a pipe), it opens that onto the
7002 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7003 file or pipe again to the caller.
7008 return $lineinfo unless @_;
7011 # If this is a valid "thing to be opened for output", tack a
7012 # '>' onto the front.
7013 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7015 # If this is a pipe, the stream points to a slave editor.
7016 $slave_editor = ( $stream =~ /^\|/ );
7018 # Open it up and unbuffer it.
7019 open( LINEINFO, "$stream" ) || &warn("Cannot open `$stream' for write");
7020 $LINEINFO = \*LINEINFO;
7021 my $save = select($LINEINFO);
7025 # Hand the file or pipe back again.
7027 } ## end sub LineInfo
7029 =head1 COMMAND SUPPORT ROUTINES
7031 These subroutines provide functionality for various commands.
7033 =head2 C<list_modules>
7035 For the C<M> command: list modules loaded and their versions.
7036 Essentially just runs through the keys in %INC, picks each package's
7037 C<$VERSION> variable, gets the file name, and formats the information
7042 sub list_modules { # versions
7046 # keys are the "as-loaded" name, values are the fully-qualified path
7047 # to the file itself.
7049 $file = $_; # get the module name
7050 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7051 s,/,::,g; # change '/' to '::'
7052 s/^perl5db$/DB/; # Special case: debugger
7053 # moves to package DB
7054 s/^Term::ReadLine::readline$/readline/; # simplify readline
7056 # If the package has a $VERSION package global (as all good packages
7057 # should!) decode it and save as partial message.
7058 if ( defined ${ $_ . '::VERSION' } ) {
7059 $version{$file} = "${ $_ . '::VERSION' } from ";
7062 # Finish up the message with the file the package came from.
7063 $version{$file} .= $INC{$file};
7064 } ## end for (keys %INC)
7066 # Hey, dumpit() formats a hash nicely, so why not use it?
7067 dumpit( $OUT, \%version );
7068 } ## end sub list_modules
7072 Sets up the monster string used to format and print the help.
7074 =head3 HELP MESSAGE FORMAT
7076 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
7077 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
7078 easy to parse and portable, but which still allows the help to be a little
7079 nicer than just plain text.
7081 Essentially, you define the command name (usually marked up with C<< B<> >>
7082 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
7083 newline. The descriptive text can also be marked up in the same way. If you
7084 need to continue the descriptive text to another line, start that line with
7085 just tabs and then enter the marked-up text.
7087 If you are modifying the help text, I<be careful>. The help-string parser is
7088 not very sophisticated, and if you don't follow these rules it will mangle the
7089 help beyond hope until you fix the string.
7095 # XXX: make sure there are tabs between the command and explanation,
7096 # or print_help will screw up your formatting if you have
7097 # eeevil ornaments enabled. This is an insane mess.
7100 Help is currently only available for the new 5.8 command set.
7101 No help is available for the old command set.
7102 We assume you know what you're doing if you switch to it.
7105 B<s> [I<expr>] Single step [in I<expr>].
7106 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7107 <B<CR>> Repeat last B<n> or B<s> command.
7108 B<r> Return from current subroutine.
7109 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7110 at the specified position.
7111 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7112 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7113 B<l> I<line> List single I<line>.
7114 B<l> I<subname> List first window of lines from subroutine.
7115 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7116 B<l> List next window of lines.
7117 B<-> List previous window of lines.
7118 B<v> [I<line>] View window around I<line>.
7119 B<.> Return to the executed line.
7120 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7121 I<filename> may be either the full name of the file, or a regular
7122 expression matching the full file name:
7123 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7124 Evals (with saved bodies) are considered to be filenames:
7125 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7126 (in the order of execution).
7127 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7128 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7129 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
7130 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7131 B<t> Toggle trace mode.
7132 B<t> I<expr> Trace through execution of I<expr>.
7133 B<b> Sets breakpoint on current line)
7134 B<b> [I<line>] [I<condition>]
7135 Set breakpoint; I<line> defaults to the current execution line;
7136 I<condition> breaks if it evaluates to true, defaults to '1'.
7137 B<b> I<subname> [I<condition>]
7138 Set breakpoint at first line of subroutine.
7139 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7140 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7141 B<b> B<postpone> I<subname> [I<condition>]
7142 Set breakpoint at first line of subroutine after
7144 B<b> B<compile> I<subname>
7145 Stop after the subroutine is compiled.
7146 B<B> [I<line>] Delete the breakpoint for I<line>.
7147 B<B> I<*> Delete all breakpoints.
7148 B<a> [I<line>] I<command>
7149 Set an action to be done before the I<line> is executed;
7150 I<line> defaults to the current execution line.
7151 Sequence is: check for breakpoint/watchpoint, print line
7152 if necessary, do action, prompt user if necessary,
7155 B<A> [I<line>] Delete the action for I<line>.
7156 B<A> I<*> Delete all actions.
7157 B<w> I<expr> Add a global watch-expression.
7159 B<W> I<expr> Delete a global watch-expression.
7160 B<W> I<*> Delete all watch-expressions.
7161 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7162 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7163 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7164 B<x> I<expr> Evals expression in list context, dumps the result.
7165 B<m> I<expr> Evals expression in list context, prints methods callable
7166 on the first element of the result.
7167 B<m> I<class> Prints methods callable via the given class.
7168 B<M> Show versions of loaded modules.
7169 B<i> I<class> Prints nested parents of given class.
7170 B<e> Display current thread id.
7171 B<E> Display all thread ids the current one will be identified: <n>.
7172 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7173 B<P> Something to do with assertions...
7175 B<<> ? List Perl commands to run before each prompt.
7176 B<<> I<expr> Define Perl command to run before each prompt.
7177 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7178 B<< *> Delete the list of perl commands to run before each prompt.
7179 B<>> ? List Perl commands to run after each prompt.
7180 B<>> I<expr> Define Perl command to run after each prompt.
7181 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7182 B<>>B< *> Delete the list of Perl commands to run after each prompt.
7183 B<{> I<db_command> Define debugger command to run before each prompt.
7184 B<{> ? List debugger commands to run before each prompt.
7185 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7186 B<{ *> Delete the list of debugger commands to run before each prompt.
7187 B<$prc> I<number> Redo a previous command (default previous command).
7188 B<$prc> I<-number> Redo number'th-to-last command.
7189 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7190 See 'B<O> I<recallCommand>' too.
7191 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7196 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7198 See 'B<O> I<shellBang>' too.
7199 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7200 B<save> I<file> Save current debugger session (actual history) to I<file>.
7201 B<rerun> Rerun session to current position.
7202 B<rerun> I<n> Rerun session to numbered command.
7203 B<rerun> I<-n> Rerun session to number'th-to-last command.
7204 B<H> I<-number> Display last number commands (default all).
7205 B<H> I<*> Delete complete history.
7206 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7207 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7208 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7209 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7210 I<command> Execute as a perl statement in current package.
7211 B<R> Pure-man-restart of debugger, some of debugger state
7212 and command-line options may be lost.
7213 Currently the following settings are preserved:
7214 history, breakpoints and actions, debugger B<O>ptions
7215 and the following command-line options: I<-w>, I<-I>, I<-e>.
7217 B<o> [I<opt>] ... Set boolean option to true
7218 B<o> [I<opt>B<?>] Query options
7219 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7220 Set options. Use quotes in spaces in value.
7221 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7222 I<pager> program for output of \"|cmd\";
7223 I<tkRunning> run Tk while prompting (with ReadLine);
7224 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7225 I<inhibit_exit> Allows stepping off the end of the script.
7226 I<ImmediateStop> Debugger should stop as early as possible.
7227 I<RemotePort> Remote hostname:port for remote debugging
7228 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7229 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7230 I<compactDump>, I<veryCompact> change style of array and hash dump;
7231 I<globPrint> whether to print contents of globs;
7232 I<DumpDBFiles> dump arrays holding debugged files;
7233 I<DumpPackages> dump symbol tables of packages;
7234 I<DumpReused> dump contents of \"reused\" addresses;
7235 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7236 I<bareStringify> Do not print the overload-stringified value;
7237 Other options include:
7238 I<PrintRet> affects printing of return value after B<r> command,
7239 I<frame> affects printing messages on subroutine entry/exit.
7240 I<AutoTrace> affects printing messages on possible breaking points.
7241 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7242 I<ornaments> affects screen appearance of the command line.
7243 I<CreateTTY> bits control attempts to create a new TTY on events:
7244 1: on fork() 2: debugger is started inside debugger
7246 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7247 You can put additional initialization options I<TTY>, I<noTTY>,
7248 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7249 `B<R>' after you set them).
7251 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7252 B<h> Summary of debugger commands.
7253 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7254 B<h h> Long help for debugger commands
7255 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7256 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7257 Set B<\$DB::doccmd> to change viewer.
7259 Type `|h h' for a paged display if this was too hard to read.
7261 "; # Fix balance of vi % matching: }}}}
7263 # note: tabs in the following section are not-so-helpful
7264 $summary = <<"END_SUM";
7265 I<List/search source lines:> I<Control script execution:>
7266 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7267 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7268 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7269 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7270 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7271 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7272 I<Debugger controls:> B<L> List break/watch/actions
7273 B<o> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7274 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7275 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7276 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7277 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7278 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7279 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7280 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7281 B<q> or B<^D> Quit B<R> Attempt a restart
7282 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7283 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7284 B<p> I<expr> Print expression (uses script's current package).
7285 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7286 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7287 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
7288 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7289 B<e> Display thread id B<E> Display all thread ids.
7290 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7293 # ')}}; # Fix balance of vi % matching
7295 # and this is really numb...
7298 B<s> [I<expr>] Single step [in I<expr>].
7299 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7300 B<CR>> Repeat last B<n> or B<s> command.
7301 B<r> Return from current subroutine.
7302 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7303 at the specified position.
7304 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7305 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7306 B<l> I<line> List single I<line>.
7307 B<l> I<subname> List first window of lines from subroutine.
7308 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7309 B<l> List next window of lines.
7310 B<-> List previous window of lines.
7311 B<w> [I<line>] List window around I<line>.
7312 B<.> Return to the executed line.
7313 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7314 I<filename> may be either the full name of the file, or a regular
7315 expression matching the full file name:
7316 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7317 Evals (with saved bodies) are considered to be filenames:
7318 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7319 (in the order of execution).
7320 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7321 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7322 B<L> List all breakpoints and actions.
7323 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7324 B<t> Toggle trace mode.
7325 B<t> I<expr> Trace through execution of I<expr>.
7326 B<b> [I<line>] [I<condition>]
7327 Set breakpoint; I<line> defaults to the current execution line;
7328 I<condition> breaks if it evaluates to true, defaults to '1'.
7329 B<b> I<subname> [I<condition>]
7330 Set breakpoint at first line of subroutine.
7331 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7332 B<b> B<load> I<filename> Set breakpoint on `require'ing the given file.
7333 B<b> B<postpone> I<subname> [I<condition>]
7334 Set breakpoint at first line of subroutine after
7336 B<b> B<compile> I<subname>
7337 Stop after the subroutine is compiled.
7338 B<d> [I<line>] Delete the breakpoint for I<line>.
7339 B<D> Delete all breakpoints.
7340 B<a> [I<line>] I<command>
7341 Set an action to be done before the I<line> is executed;
7342 I<line> defaults to the current execution line.
7343 Sequence is: check for breakpoint/watchpoint, print line
7344 if necessary, do action, prompt user if necessary,
7346 B<a> [I<line>] Delete the action for I<line>.
7347 B<A> Delete all actions.
7348 B<W> I<expr> Add a global watch-expression.
7349 B<W> Delete all watch-expressions.
7350 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7351 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7352 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7353 B<x> I<expr> Evals expression in list context, dumps the result.
7354 B<m> I<expr> Evals expression in list context, prints methods callable
7355 on the first element of the result.
7356 B<m> I<class> Prints methods callable via the given class.
7358 B<<> ? List Perl commands to run before each prompt.
7359 B<<> I<expr> Define Perl command to run before each prompt.
7360 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7361 B<>> ? List Perl commands to run after each prompt.
7362 B<>> I<expr> Define Perl command to run after each prompt.
7363 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7364 B<{> I<db_command> Define debugger command to run before each prompt.
7365 B<{> ? List debugger commands to run before each prompt.
7366 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7367 B<$prc> I<number> Redo a previous command (default previous command).
7368 B<$prc> I<-number> Redo number'th-to-last command.
7369 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7370 See 'B<O> I<recallCommand>' too.
7371 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7376 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7378 See 'B<O> I<shellBang>' too.
7379 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7380 B<H> I<-number> Display last number commands (default all).
7381 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7382 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7383 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7384 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7385 I<command> Execute as a perl statement in current package.
7386 B<v> Show versions of loaded modules.
7387 B<R> Pure-man-restart of debugger, some of debugger state
7388 and command-line options may be lost.
7389 Currently the following settings are preserved:
7390 history, breakpoints and actions, debugger B<O>ptions
7391 and the following command-line options: I<-w>, I<-I>, I<-e>.
7393 B<O> [I<opt>] ... Set boolean option to true
7394 B<O> [I<opt>B<?>] Query options
7395 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7396 Set options. Use quotes in spaces in value.
7397 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7398 I<pager> program for output of \"|cmd\";
7399 I<tkRunning> run Tk while prompting (with ReadLine);
7400 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7401 I<inhibit_exit> Allows stepping off the end of the script.
7402 I<ImmediateStop> Debugger should stop as early as possible.
7403 I<RemotePort> Remote hostname:port for remote debugging
7404 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7405 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7406 I<compactDump>, I<veryCompact> change style of array and hash dump;
7407 I<globPrint> whether to print contents of globs;
7408 I<DumpDBFiles> dump arrays holding debugged files;
7409 I<DumpPackages> dump symbol tables of packages;
7410 I<DumpReused> dump contents of \"reused\" addresses;
7411 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7412 I<bareStringify> Do not print the overload-stringified value;
7413 Other options include:
7414 I<PrintRet> affects printing of return value after B<r> command,
7415 I<frame> affects printing messages on subroutine entry/exit.
7416 I<AutoTrace> affects printing messages on possible breaking points.
7417 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7418 I<ornaments> affects screen appearance of the command line.
7419 I<CreateTTY> bits control attempts to create a new TTY on events:
7420 1: on fork() 2: debugger is started inside debugger
7422 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7423 You can put additional initialization options I<TTY>, I<noTTY>,
7424 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7425 `B<R>' after you set them).
7427 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7428 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7429 B<h h> Summary of debugger commands.
7430 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7431 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7432 Set B<\$DB::doccmd> to change viewer.
7434 Type `|h' for a paged display if this was too hard to read.
7436 "; # Fix balance of vi % matching: }}}}
7438 # note: tabs in the following section are not-so-helpful
7439 $pre580_summary = <<"END_SUM";
7440 I<List/search source lines:> I<Control script execution:>
7441 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7442 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7443 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
7444 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7445 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7446 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
7447 I<Debugger controls:> B<L> List break/watch/actions
7448 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7449 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7450 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
7451 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7452 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
7453 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
7454 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7455 B<q> or B<^D> Quit B<R> Attempt a restart
7456 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7457 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7458 B<p> I<expr> Print expression (uses script's current package).
7459 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7460 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7461 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
7462 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7463 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7466 # ')}}; # Fix balance of vi % matching
7468 } ## end sub sethelp
7470 =head2 C<print_help()>
7472 Most of what C<print_help> does is just text formatting. It finds the
7473 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
7474 terminal control characters to simulate them (courtesy of
7475 C<Term::ReadLine::TermCap>).
7482 # Restore proper alignment destroyed by eeevil I<> and B<>
7483 # ornaments: A pox on both their houses!
7485 # A help command will have everything up to and including
7486 # the first tab sequence padded into a field 16 (or if indented 20)
7487 # wide. If it's wider than that, an extra space will be added.
7489 ^ # only matters at start of line
7490 ( \040{4} | \t )* # some subcommands are indented
7491 ( < ? # so <CR> works
7492 [BI] < [^\t\n] + ) # find an eeevil ornament
7493 ( \t+ ) # original separation, discarded
7494 ( .* ) # this will now start (no earlier) than
7497 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
7498 my $clean = $command;
7499 $clean =~ s/[BI]<([^>]*)>/$1/g;
7501 # replace with this whole string:
7502 ($leadwhite ? " " x 4 : "")
7504 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
7509 s{ # handle bold ornaments
7510 B < ( [^>] + | > ) >
7512 $Term::ReadLine::TermCap::rl_term_set[2]
7514 . $Term::ReadLine::TermCap::rl_term_set[3]
7517 s{ # handle italic ornaments
7518 I < ( [^>] + | > ) >
7520 $Term::ReadLine::TermCap::rl_term_set[0]
7522 . $Term::ReadLine::TermCap::rl_term_set[1]
7527 } ## end sub print_help
7531 This routine does a lot of gyrations to be sure that the pager is C<less>.
7532 It checks for C<less> masquerading as C<more> and records the result in
7533 C<$ENV{LESS}> so we don't have to go through doing the stats again.
7539 # We already know if this is set.
7540 return if defined $ENV{LESS} && $ENV{LESS} =~ /r/;
7542 # Pager is less for sure.
7543 my $is_less = $pager =~ /\bless\b/;
7544 if ( $pager =~ /\bmore\b/ ) {
7546 # Nope, set to more. See what's out there.
7547 my @st_more = stat('/usr/bin/more');
7548 my @st_less = stat('/usr/bin/less');
7550 # is it really less, pretending to be more?
7553 && $st_more[0] == $st_less[0]
7554 && $st_more[1] == $st_less[1];
7555 } ## end if ($pager =~ /\bmore\b/)
7557 # changes environment!
7558 # 'r' added so we don't do (slow) stats again.
7559 $ENV{LESS} .= 'r' if $is_less;
7560 } ## end sub fix_less
7562 =head1 DIE AND WARN MANAGEMENT
7566 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
7567 to debug a debugger problem.
7569 It does its best to report the error that occurred, and then forces the
7570 program, debugger, and everything to die.
7576 # No entry/exit messages.
7579 # No return value prints.
7582 # set the abort signal handling to the default (just terminate).
7583 $SIG{'ABRT'} = 'DEFAULT';
7585 # If we enter the signal handler recursively, kill myself with an
7586 # abort signal (so we just terminate).
7587 kill 'ABRT', $$ if $panic++;
7589 # If we can show detailed info, do so.
7590 if ( defined &Carp::longmess ) {
7592 # Don't recursively enter the warn handler, since we're carping.
7593 local $SIG{__WARN__} = '';
7595 # Skip two levels before reporting traceback: we're skipping
7596 # mydie and confess.
7597 local $Carp::CarpLevel = 2; # mydie + confess
7599 # Tell us all about it.
7600 &warn( Carp::longmess("Signal @_") );
7603 # No Carp. Tell us about the signal as best we can.
7606 print $DB::OUT "Got signal @_\n";
7611 } ## end sub diesignal
7615 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
7616 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
7622 # No entry/exit trace.
7625 # No return value printing.
7628 # Turn off warn and die handling to prevent recursive entries to this
7630 local $SIG{__WARN__} = '';
7631 local $SIG{__DIE__} = '';
7633 # Load Carp if we can. If $^S is false (current thing being compiled isn't
7634 # done yet), we may not be able to do a require.
7635 eval { require Carp }
7636 if defined $^S; # If error/warning during compilation,
7637 # require may be broken.
7639 # Use the core warn() unless Carp loaded OK.
7641 "\nCannot print stack trace, load with -MCarp option to see stack" ),
7643 unless defined &Carp::longmess;
7645 # Save the current values of $single and $trace, and then turn them off.
7646 my ( $mysingle, $mytrace ) = ( $single, $trace );
7650 # We can call Carp::longmess without its being "debugged" (which we
7651 # don't want - we just want to use it!). Capture this for later.
7652 my $mess = Carp::longmess(@_);
7654 # Restore $single and $trace to their original values.
7655 ( $single, $trace ) = ( $mysingle, $mytrace );
7657 # Use the debugger's own special way of printing warnings to print
7658 # the stack trace message.
7664 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
7665 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
7666 single stepping and tracing during the call to C<Carp::longmess> to avoid
7667 debugging it - we just want to use it.
7669 If C<dieLevel> is zero, we let the program being debugged handle the
7670 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
7671 the debugger takes over all exception handling, printing a backtrace and
7672 displaying the exception via its C<dbwarn()> routine.
7679 local $SIG{__DIE__} = '';
7680 local $SIG{__WARN__} = '';
7684 if ( $dieLevel > 2 ) {
7685 local $SIG{__WARN__} = \&dbwarn;
7686 &warn(@_); # Yell no matter what
7689 if ( $dieLevel < 2 ) {
7690 die @_ if $^S; # in eval propagate
7693 # The code used to check $^S to see if compiliation of the current thing
7694 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
7695 eval { require Carp };
7698 "\nCannot print stack trace, load with -MCarp option to see stack" )
7699 unless defined &Carp::longmess;
7701 # We do not want to debug this chunk (automatic disabling works
7702 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
7703 # get the stack trace from Carp::longmess (if possible), restore $signal
7704 # and $trace, and then die with the stack trace.
7705 my ( $mysingle, $mytrace ) = ( $single, $trace );
7711 package Carp; # Do not include us in the list
7712 eval { $mess = Carp::longmess(@_); };
7714 ( $single, $trace ) = ( $mysingle, $mytrace );
7718 =head2 C<warnlevel()>
7720 Set the C<$DB::warnLevel> variable that stores the value of the
7721 C<warnLevel> option. Calling C<warnLevel()> with a positive value
7722 results in the debugger taking over all warning handlers. Setting
7723 C<warnLevel> to zero leaves any warning handlers set up by the program
7724 being debugged in place.
7730 $prevwarn = $SIG{__WARN__} unless $warnLevel;
7733 $SIG{__WARN__} = \&DB::dbwarn;
7736 $SIG{__WARN__} = $prevwarn;
7740 } ## end sub warnLevel
7744 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
7745 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
7746 zero lets you use your own C<die()> handler.
7753 $prevdie = $SIG{__DIE__} unless $dieLevel;
7757 # Always set it to dbdie() for non-zero values.
7758 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
7760 # No longer exists, so don't try to use it.
7761 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
7763 # If we've finished initialization, mention that stack dumps
7764 # are enabled, If dieLevel is 1, we won't stack dump if we die
7766 print $OUT "Stack dump during die enabled",
7767 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
7770 # XXX This is probably obsolete, given that diehard() is gone.
7771 print $OUT "Dump printed too.\n" if $dieLevel > 2;
7772 } ## end if ($dieLevel)
7774 # Put the old one back if there was one.
7776 $SIG{__DIE__} = $prevdie;
7777 print $OUT "Default die handler restored.\n";
7781 } ## end sub dieLevel
7783 =head2 C<signalLevel>
7785 Number three in a series: set C<signalLevel> to zero to keep your own
7786 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
7787 takes over and handles them with C<DB::diesignal()>.
7793 $prevsegv = $SIG{SEGV} unless $signalLevel;
7794 $prevbus = $SIG{BUS} unless $signalLevel;
7795 $signalLevel = shift;
7797 $SIG{SEGV} = \&DB::diesignal;
7798 $SIG{BUS} = \&DB::diesignal;
7801 $SIG{SEGV} = $prevsegv;
7802 $SIG{BUS} = $prevbus;
7806 } ## end sub signalLevel
7808 =head1 SUBROUTINE DECODING SUPPORT
7810 These subroutines are used during the C<x> and C<X> commands to try to
7811 produce as much information as possible about a code reference. They use
7812 L<Devel::Peek> to try to find the glob in which this code reference lives
7813 (if it does) - this allows us to actually code references which correspond
7814 to named subroutines (including those aliased via glob assignment).
7816 =head2 C<CvGV_name()>
7818 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
7819 via that routine. If this fails, return the reference again (when the
7820 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
7826 my $name = CvGV_name_or_bust($in);
7827 defined $name ? $name : $in;
7830 =head2 C<CvGV_name_or_bust> I<coderef>
7832 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
7833 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
7834 find a glob for this ref.
7836 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
7840 sub CvGV_name_or_bust {
7842 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
7843 return unless ref $in;
7844 $in = \&$in; # Hard reference...
7845 eval { require Devel::Peek; 1 } or return;
7846 my $gv = Devel::Peek::CvGV($in) or return;
7847 *$gv{PACKAGE} . '::' . *$gv{NAME};
7848 } ## end sub CvGV_name_or_bust
7852 A utility routine used in various places; finds the file where a subroutine
7853 was defined, and returns that filename and a line-number range.
7855 Tries to use C<@sub> first; if it can't find it there, it tries building a
7856 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
7857 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
7858 this way, it brute-force searches C<%sub>, checking for identical references.
7865 return unless defined &$subr;
7866 my $name = CvGV_name_or_bust($subr);
7868 $data = $sub{$name} if defined $name;
7869 return $data if defined $data;
7872 $subr = \&$subr; # Hard reference
7875 $s = $_, last if $subr eq \&$_;
7879 } ## end sub find_sub
7883 A subroutine that uses the utility function C<methods_via> to find all the
7884 methods in the class corresponding to the current reference and in
7891 # Figure out the class - either this is the class or it's a reference
7892 # to something blessed into that class.
7894 $class = ref $class if ref $class;
7898 # Show the methods that this class has.
7899 methods_via( $class, '', 1 );
7901 # Show the methods that UNIVERSAL has.
7902 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
7903 } ## end sub methods
7905 =head2 C<methods_via($class, $prefix, $crawl_upward)>
7907 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
7908 all the parent class methods. C<$class> is the name of the next class to
7909 try; C<$prefix> is the message prefix, which gets built up as we go up the
7910 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
7911 higher in the C<@ISA> tree, 0 if we should stop.
7917 # If we've processed this class already, just quit.
7919 return if $seen{$class}++;
7921 # This is a package that is contributing the methods we're about to print.
7923 my $prepend = $prefix ? "via $prefix: " : '';
7928 # Keep if this is a defined subroutine in this class.
7929 grep { defined &{ ${"${class}::"}{$_} } }
7931 # Extract from all the symbols in this class.
7932 sort keys %{"${class}::"}
7936 # If we printed this already, skip it.
7937 next if $seen{$name}++;
7939 # Print the new method name.
7942 print $DB::OUT "$prepend$name\n";
7943 } ## end for $name (grep { defined...
7945 # If the $crawl_upward argument is false, just quit here.
7946 return unless shift;
7948 # $crawl_upward true: keep going up the tree.
7949 # Find all the classes this one is a subclass of.
7950 for $name ( @{"${class}::ISA"} ) {
7952 # Set up the new prefix.
7953 $prepend = $prefix ? $prefix . " -> $name" : $name;
7955 # Crawl up the tree and keep trying to crawl up.
7956 methods_via( $name, $prepend, 1 );
7958 } ## end sub methods_via
7960 =head2 C<setman> - figure out which command to use to show documentation
7962 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
7967 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|MacOS|NetWare)\z/s
7968 ? "man" # O Happy Day!
7969 : "perldoc"; # Alas, poor unfortunates
7972 =head2 C<runman> - run the appropriate command to show documentation
7974 Accepts a man page name; runs the appropriate command to display it (set up
7975 during debugger initialization). Uses C<DB::system> to avoid mucking up the
7976 program's STDIN and STDOUT.
7983 &system("$doccmd $doccmd");
7987 # this way user can override, like with $doccmd="man -Mwhatever"
7988 # or even just "man " to disable the path check.
7989 unless ( $doccmd eq 'man' ) {
7990 &system("$doccmd $page");
7994 $page = 'perl' if lc($page) eq 'help';
7997 my $man1dir = $Config::Config{'man1dir'};
7998 my $man3dir = $Config::Config{'man3dir'};
7999 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8001 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8002 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8003 chop $manpath if $manpath;
8005 # harmless if missing, I figure
8006 my $oldpath = $ENV{MANPATH};
8007 $ENV{MANPATH} = $manpath if $manpath;
8008 my $nopathopt = $^O =~ /dunno what goes here/;
8013 # I just *know* there are men without -M
8014 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8019 unless ( $page =~ /^perl\w/ ) {
8020 # do it this way because its easier to slurp in to keep up to date - clunky though.
8159 if (grep { $page eq $_ } @pods) {
8161 CORE::system( $doccmd,
8162 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8164 } ## end if (grep { $page eq $_...
8165 } ## end unless ($page =~ /^perl\w/)
8166 } ## end if (CORE::system($doccmd...
8167 if ( defined $oldpath ) {
8168 $ENV{MANPATH} = $manpath;
8171 delete $ENV{MANPATH};
8175 #use Carp; # This did break, left for debugging
8177 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
8179 Because of the way the debugger interface to the Perl core is designed, any
8180 debugger package globals that C<DB::sub()> requires have to be defined before
8181 any subroutines can be called. These are defined in the second C<BEGIN> block.
8183 This block sets things up so that (basically) the world is sane
8184 before the debugger starts executing. We set up various variables that the
8185 debugger has to have set up before the Perl core starts running:
8191 The debugger's own filehandles (copies of STD and STDOUT for now).
8195 Characters for shell escapes, the recall command, and the history command.
8199 The maximum recursion depth.
8203 The size of a C<w> command's window.
8207 The before-this-line context to be printed in a C<v> (view a window around this line) command.
8211 The fact that we're not in a sub at all right now.
8215 The default SIGINT handler for the debugger.
8219 The appropriate value of the flag in C<$^D> that says the debugger is running
8223 The current debugger recursion level
8227 The list of postponed items and the C<$single> stack (XXX define this)
8231 That we want no return values and no subroutine entry/exit trace.
8237 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
8239 BEGIN { # This does not compile, alas. (XXX eh?)
8240 $IN = \*STDIN; # For bugs before DB::OUT has been opened
8241 $OUT = \*STDERR; # For errors before DB::OUT has been opened
8243 # Define characters used by command parsing.
8244 $sh = '!'; # Shell escape (does not work)
8245 $rc = ','; # Recall command (does not work)
8246 @hist = ('?'); # Show history (does not work)
8247 @truehist = (); # Can be saved for replay (per session)
8249 # This defines the point at which you get the 'deep recursion'
8250 # warning. It MUST be defined or the debugger will not load.
8253 # Number of lines around the current one that are shown in the
8257 # How much before-the-current-line context the 'v' command should
8258 # use in calculating the start of the window it will display.
8261 # We're not in any sub yet, but we need this to be a defined value.
8264 # Set up the debugger's interrupt handler. It simply sets a flag
8265 # ($signal) that DB::DB() will check before each command is executed.
8266 $SIG{INT} = \&DB::catch;
8268 # The following lines supposedly, if uncommented, allow the debugger to
8269 # debug itself. Perhaps we can try that someday.
8270 # This may be enabled to debug debugger:
8271 #$warnLevel = 1 unless defined $warnLevel;
8272 #$dieLevel = 1 unless defined $dieLevel;
8273 #$signalLevel = 1 unless defined $signalLevel;
8275 # This is the flag that says "a debugger is running, please call
8276 # DB::DB and DB::sub". We will turn it on forcibly before we try to
8277 # execute anything in the user's context, because we always want to
8279 $db_stop = 0; # Compiler warning ...
8280 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
8282 # This variable records how many levels we're nested in debugging. Used
8283 # Used in the debugger prompt, and in determining whether it's all over or
8285 $level = 0; # Level of recursive debugging
8287 # "Triggers bug (?) in perl if we postpone this until runtime."
8288 # XXX No details on this yet, or whether we should fix the bug instead
8289 # of work around it. Stay tuned.
8290 @postponed = @stack = (0);
8292 # Used to track the current stack depth using the auto-stacked-variable
8294 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
8296 # Don't print return values on exiting a subroutine.
8299 # No extry/exit tracing.
8304 BEGIN { $^W = $ini_warn; } # Switch warnings back
8306 =head1 READLINE SUPPORT - COMPLETION FUNCTION
8310 C<readline> support - adds command completion to basic C<readline>.
8312 Returns a list of possible completions to C<readline> when invoked. C<readline>
8313 will print the longest common substring following the text already entered.
8315 If there is only a single possible completion, C<readline> will use it in full.
8317 This code uses C<map> and C<grep> heavily to create lists of possible
8318 completion. Think LISP in this section.
8324 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
8325 # $text is the text to be completed.
8326 # $line is the incoming line typed by the user.
8327 # $start is the start of the text to be completed in the incoming line.
8328 my ( $text, $line, $start ) = @_;
8330 # Save the initial text.
8331 # The search pattern is current package, ::, extract the next qualifier
8332 # Prefix and pack are set to undef.
8333 my ( $itext, $search, $prefix, $pack ) =
8334 ( $text, "^\Q${'package'}::\E([^:]+)\$" );
8336 =head3 C<b postpone|compile>
8342 Find all the subroutines that might match in this package
8346 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
8350 Include all the rest of the subs that are known
8354 C<grep> out the ones that match the text we have so far
8358 Return this as the list of possible completions
8364 return sort grep /^\Q$text/, ( keys %sub ),
8365 qw(postpone load compile), # subroutines
8366 ( map { /$search/ ? ($1) : () } keys %sub )
8367 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
8371 Get all the possible files from C<@INC> as it currently stands and
8372 select the ones that match the text so far.
8376 return sort grep /^\Q$text/, values %INC # files
8377 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
8379 =head3 C<V> (list variable) and C<m> (list modules)
8381 There are two entry points for these commands:
8383 =head4 Unqualified package names
8385 Get the top-level packages and grab everything that matches the text
8386 so far. For each match, recursively complete the partial packages to
8387 get all possible matching packages. Return this sorted list.
8391 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8392 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
8393 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
8395 =head4 Qualified package names
8397 Take a partially-qualified package and find all subpackages for it
8398 by getting all the subpackages for the package so far, matching all
8399 the subpackages against the text, and discarding all of them which
8400 start with 'main::'. Return this list.
8404 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8405 grep !/^main::/, grep /^\Q$text/,
8406 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () } keys %{ $prefix . '::' }
8407 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
8408 and $text =~ /^(.*[^:])::?(\w*)$/
8411 =head3 C<f> - switch files
8413 Here, we want to get a fully-qualified filename for the C<f> command.
8418 =item 1. The original source file itself
8420 =item 2. A file from C<@INC>
8422 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
8428 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
8429 # We might possibly want to switch to an eval (which has a "filename"
8430 # like '(eval 9)'), so we may need to clean up the completion text
8431 # before proceeding.
8432 $prefix = length($1) - length($text);
8437 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
8438 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
8439 out of C<%main::>, add the initial source file, and extract the ones that
8440 match the completion text so far.
8445 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
8447 } ## end if ($line =~ /^\|*f\s+(.*)/)
8449 =head3 Subroutine name completion
8451 We look through all of the defined subs (the keys of C<%sub>) and
8452 return both all the possible matches to the subroutine name plus
8453 all the matches qualified to the current package.
8457 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
8458 $text = substr $text, 1;
8460 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
8462 map { /$search/ ? ($1) : () }
8465 } ## end if ((substr $text, 0, ...
8467 =head3 Scalar, array, and hash completion: partially qualified package
8469 Much like the above, except we have to do a little more cleanup:
8473 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
8481 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
8485 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
8491 Figure out the prefix vs. what needs completing.
8495 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
8502 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
8506 my @out = map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
8513 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.
8517 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8518 return db_complete( $out[0], $line, $start );
8521 # Return the list of possibles.
8524 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
8530 =head3 Symbol completion: current package or package C<main>.
8534 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
8542 If it's C<main>, delete main to just get C<::> leading.
8546 $pack = ( $package eq 'main' ? '' : $package ) . '::';
8552 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
8556 $prefix = substr $text, 0, 1;
8557 $text = substr $text, 1;
8563 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
8567 my @out = map "$prefix$_", grep /^\Q$text/,
8568 ( grep /^_?[a-zA-Z]/, keys %$pack ),
8569 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
8573 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
8579 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8580 return db_complete( $out[0], $line, $start );
8583 # Return the list of possibles.
8585 } ## end if ($text =~ /^[\$@%]/)
8589 We use C<option_val()> to look up the current value of the option. If there's
8590 only a single value, we complete the command in such a way that it is a
8591 complete command for setting the option in question. If there are multiple
8592 possible values, we generate a command consisting of the option plus a trailing
8593 question mark, which, if executed, will list the current value of the option.
8597 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
8598 { # Options after space
8599 # We look for the text to be matched in the list of possible options,
8600 # and fetch the current value.
8601 my @out = grep /^\Q$text/, @options;
8602 my $val = option_val( $out[0], undef );
8604 # Set up a 'query option's value' command.
8606 if ( not defined $val or $val =~ /[\n\r]/ ) {
8608 # There's really nothing else we can do.
8611 # We have a value. Create a proper option-setting command.
8612 elsif ( $val =~ /\s/ ) {
8614 # XXX This may be an extraneous variable.
8617 # We'll want to quote the string (because of the embedded
8618 # whtespace), but we want to make sure we don't end up with
8619 # mismatched quote characters. We try several possibilities.
8620 foreach $l ( split //, qq/\"\'\#\|/ ) {
8622 # If we didn't find this quote character in the value,
8623 # quote it using this quote character.
8624 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
8626 } ## end elsif ($val =~ /\s/)
8628 # Don't need any quotes.
8633 # If there were multiple possible values, return '? ', which
8634 # makes the command into a query command. If there was just one,
8635 # have readline append that.
8636 $rl_attribs->{completer_terminator_character} =
8637 ( @out == 1 ? $out : '? ' );
8639 # Return list of possibilities.
8641 } ## end if ((substr $line, 0, ...
8643 =head3 Filename completion
8645 For entering filenames. We simply call C<readline>'s C<filename_list()>
8646 method with the completion text to get the possible completions.
8650 return $term->filename_list($text); # filenames
8652 } ## end sub db_complete
8654 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
8656 Functions that possibly ought to be somewhere else.
8666 print $OUT "Use `q' to quit or `R' to restart. `h q' for details.\n";
8671 If we have $ini_pids, save it in the environment; else remove it from the
8672 environment. Used by the C<R> (restart) command.
8677 if ( defined($ini_pids) ) {
8678 $ENV{PERLDB_PIDS} = $ini_pids;
8681 delete( $ENV{PERLDB_PIDS} );
8683 } ## end sub clean_ENV
8685 # PERLDBf_... flag names from perl.h
8686 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
8689 %DollarCaretP_flags = (
8690 PERLDBf_SUB => 0x01, # Debug sub enter/exit
8691 PERLDBf_LINE => 0x02, # Keep line #
8692 PERLDBf_NOOPT => 0x04, # Switch off optimizations
8693 PERLDBf_INTER => 0x08, # Preserve more data
8694 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
8695 PERLDBf_SINGLE => 0x20, # Start with single-step on
8696 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
8697 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
8698 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
8699 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
8700 PERLDBf_ASSERTION => 0x400, # Debug assertion subs enter/exit
8701 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO, _ASSERTION
8704 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
8707 sub parse_DollarCaretP_flags {
8712 foreach my $f ( split /\s*\|\s*/, $flags ) {
8714 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
8717 elsif ( $f =~ /^(\d+)$/ ) {
8720 elsif ( $f =~ /^DEFAULT$/i ) {
8721 $value = $DollarCaretP_flags{PERLDB_ALL};
8724 $f =~ /^(?:PERLDBf_)?(.*)$/i;
8725 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
8726 unless ( defined $value ) {
8728 "Unrecognized \$^P flag '$f'!\n",
8729 "Acceptable flags are: "
8730 . join( ', ', sort keys %DollarCaretP_flags ),
8731 ", and hexadecimal and decimal numbers.\n"
8741 sub expand_DollarCaretP_flags {
8742 my $DollarCaretP = shift;
8745 my $n = ( 1 << $_ );
8746 ( $DollarCaretP & $n )
8747 ? ( $DollarCaretP_flags_r{$n}
8748 || sprintf( '0x%x', $n ) )
8752 return @bits ? join( '|', @bits ) : 0;
8759 Rerun the current session to:
8761 rerun current position
8763 rerun 4 command number 4
8765 rerun -4 current command minus 4 (go back 4 steps)
8767 Whether this always makes sense, in the current context is unknowable, and is
8768 in part left as a useful exersize for the reader. This sub returns the
8769 appropriate arguments to rerun the current session.
8776 pop(@truehist); # strim
8777 unless (defined $truehist[$i]) {
8778 print "Unable to return to non-existent command: $i\n";
8780 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
8781 my @temp = @truehist; # store
8782 push(@DB::typeahead, @truehist); # saved
8783 @truehist = @hist = (); # flush
8784 @args = &restart(); # setup
8785 &get_list("PERLDB_HIST"); # clean
8786 &set_list("PERLDB_HIST", @temp); # reset
8793 Restarting the debugger is a complex operation that occurs in several phases.
8794 First, we try to reconstruct the command line that was used to invoke Perl
8800 # I may not be able to resurrect you, but here goes ...
8802 "Warning: some settings and command-line options may be lost!\n";
8803 my ( @script, @flags, $cl );
8805 # If warn was on before, turn it on again.
8806 push @flags, '-w' if $ini_warn;
8807 if ( $ini_assertion and @{^ASSERTING} ) {
8809 ( map { /\:\^\(\?\:(.*)\)\$\)/ ? "-A$1" : "-A$_" }
8813 # Rebuild the -I flags that were on the initial
8816 push @flags, '-I', $_;
8819 # Turn on taint if it was on before.
8820 push @flags, '-T' if ${^TAINT};
8822 # Arrange for setting the old INC:
8823 # Save the current @init_INC in the environment.
8824 set_list( "PERLDB_INC", @ini_INC );
8826 # If this was a perl one-liner, go to the "file"
8827 # corresponding to the one-liner read all the lines
8828 # out of it (except for the first one, which is going
8829 # to be added back on again when 'perl -d' runs: that's
8830 # the 'require perl5db.pl;' line), and add them back on
8831 # to the command line to be executed.
8833 for ( 1 .. $#{'::_<-e'} ) { # The first line is PERL5DB
8834 chomp( $cl = ${'::_<-e'}[$_] );
8835 push @script, '-e', $cl;
8837 } ## end if ($0 eq '-e')
8839 # Otherwise we just reuse the original name we had
8847 After the command line has been reconstructed, the next step is to save
8848 the debugger's status in environment variables. The C<DB::set_list> routine
8849 is used to save aggregate variables (both hashes and arrays); scalars are
8850 just popped into environment variables directly.
8854 # If the terminal supported history, grab it and
8855 # save that in the environment.
8856 set_list( "PERLDB_HIST",
8857 $term->Features->{getHistory}
8861 # Find all the files that were visited during this
8862 # session (i.e., the debugger had magic hashes
8863 # corresponding to them) and stick them in the environment.
8864 my @had_breakpoints = keys %had_breakpoints;
8865 set_list( "PERLDB_VISITED", @had_breakpoints );
8867 # Save the debugger options we chose.
8868 set_list( "PERLDB_OPT", %option );
8869 # set_list( "PERLDB_OPT", options2remember() );
8871 # Save the break-on-loads.
8872 set_list( "PERLDB_ON_LOAD", %break_on_load );
8876 The most complex part of this is the saving of all of the breakpoints. They
8877 can live in an awful lot of places, and we have to go through all of them,
8878 find the breakpoints, and then save them in the appropriate environment
8879 variable via C<DB::set_list>.
8883 # Go through all the breakpoints and make sure they're
8886 for ( 0 .. $#had_breakpoints ) {
8888 # We were in this file.
8889 my $file = $had_breakpoints[$_];
8891 # Grab that file's magic line hash.
8892 *dbline = $main::{ '_<' . $file };
8894 # Skip out if it doesn't exist, or if the breakpoint
8895 # is in a postponed file (we'll do postponed ones
8897 next unless %dbline or $postponed_file{$file};
8899 # In an eval. This is a little harder, so we'll
8900 # do more processing on that below.
8901 ( push @hard, $file ), next
8902 if $file =~ /^\(\w*eval/;
8904 # XXX I have no idea what this is doing. Yet.
8906 @add = %{ $postponed_file{$file} }
8907 if $postponed_file{$file};
8909 # Save the list of all the breakpoints for this file.
8910 set_list( "PERLDB_FILE_$_", %dbline, @add );
8911 } ## end for (0 .. $#had_breakpoints)
8913 # The breakpoint was inside an eval. This is a little
8914 # more difficult. XXX and I don't understand it.
8916 # Get over to the eval in question.
8917 *dbline = $main::{ '_<' . $_ };
8918 my ( $quoted, $sub, %subs, $line ) = quotemeta $_;
8919 for $sub ( keys %sub ) {
8920 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
8921 $subs{$sub} = [ $1, $2 ];
8925 "No subroutines in $_, ignoring breakpoints.\n";
8928 LINES: for $line ( keys %dbline ) {
8930 # One breakpoint per sub only:
8931 my ( $offset, $sub, $found );
8932 SUBS: for $sub ( keys %subs ) {
8935 $line # Not after the subroutine
8937 not defined $offset # Not caught
8943 $offset = $line - $subs{$sub}->[0];
8944 $offset = "+$offset", last SUBS
8946 } ## end if ($subs{$sub}->[1] >=...
8947 } ## end for $sub (keys %subs)
8948 if ( defined $offset ) {
8949 $postponed{$found} =
8950 "break $offset if $dbline{$line}";
8954 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
8956 } ## end for $line (keys %dbline)
8957 } ## end for (@hard)
8959 # Save the other things that don't need to be
8961 set_list( "PERLDB_POSTPONE", %postponed );
8962 set_list( "PERLDB_PRETYPE", @$pretype );
8963 set_list( "PERLDB_PRE", @$pre );
8964 set_list( "PERLDB_POST", @$post );
8965 set_list( "PERLDB_TYPEAHEAD", @typeahead );
8967 # We are oficially restarting.
8968 $ENV{PERLDB_RESTART} = 1;
8970 # We are junking all child debuggers.
8971 delete $ENV{PERLDB_PIDS}; # Restore ini state
8973 # Set this back to the initial pid.
8974 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
8978 After all the debugger status has been saved, we take the command we built up
8979 and then return it, so we can C<exec()> it. The debugger will spot the
8980 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
8981 from the environment.
8985 # And run Perl again. Add the "-d" flag, all the
8986 # flags we built up, the script (whether a one-liner
8987 # or a file), add on the -emacs flag for a slave editor,
8988 # and then the old arguments.
8990 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
8996 =head1 END PROCESSING - THE C<END> BLOCK
8998 Come here at the very end of processing. We want to go into a
8999 loop where we allow the user to enter commands and interact with the
9000 debugger, but we don't want anything else to execute.
9002 First we set the C<$finished> variable, so that some commands that
9003 shouldn't be run after the end of program quit working.
9005 We then figure out whether we're truly done (as in the user entered a C<q>
9006 command, or we finished execution while running nonstop). If we aren't,
9007 we set C<$single> to 1 (causing the debugger to get control again).
9009 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9010 message and returns control to the debugger. Repeat.
9012 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9013 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9014 break, run to completion.).
9019 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9020 $fall_off_end = 1 unless $inhibit_exit;
9022 # Do not stop in at_exit() and destructors on exit:
9023 $DB::single = !$fall_off_end && !$runnonstop;
9024 DB::fake::at_exit() unless $fall_off_end or $runnonstop;
9027 =head1 PRE-5.8 COMMANDS
9029 Some of the commands changed function quite a bit in the 5.8 command
9030 realignment, so much so that the old code had to be replaced completely.
9031 Because we wanted to retain the option of being able to go back to the
9032 former command set, we moved the old code off to this section.
9034 There's an awful lot of duplicated code here. We've duplicated the
9035 comments to keep things clear.
9039 Does nothing. Used to I<turn off> commands.
9043 sub cmd_pre580_null {
9048 =head2 Old C<a> command.
9050 This version added actions if you supplied them, and deleted them
9059 # Argument supplied. Add the action.
9060 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9062 # If the line isn't there, use the current line.
9066 # If there is an action ...
9069 # ... but the line isn't breakable, skip it.
9070 if ( $dbline[$i] == 0 ) {
9071 print $OUT "Line $i may not have an action.\n";
9075 # ... and the line is breakable:
9076 # Mark that there's an action in this file.
9077 $had_breakpoints{$filename} |= 2;
9079 # Delete any current action.
9080 $dbline{$i} =~ s/\0[^\0]*//;
9082 # Add the new action, continuing the line as needed.
9083 $dbline{$i} .= "\0" . action($j);
9085 } ## end if (length $j)
9087 # No action supplied.
9090 # Delete the action.
9091 $dbline{$i} =~ s/\0[^\0]*//;
9093 # Mark as having no break or action if nothing's left.
9094 delete $dbline{$i} if $dbline{$i} eq '';
9096 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9097 } ## end sub cmd_pre580_a
9099 =head2 Old C<b> command
9111 if ( $cmd =~ /^load\b\s*(.*)/ ) {
9117 # b compile|postpone <some sub> [<condition>]
9118 # The interpreter actually traps this one for us; we just put the
9119 # necessary condition in the %postponed hash.
9120 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
9122 # Capture the condition if there is one. Make it true if none.
9123 my $cond = length $3 ? $3 : '1';
9125 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
9126 # if it was 'compile'.
9127 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
9129 # De-Perl4-ify the name - ' separators to ::.
9130 $subname =~ s/\'/::/g;
9132 # Qualify it into the current package unless it's already qualified.
9133 $subname = "${'package'}::" . $subname
9134 unless $subname =~ /::/;
9136 # Add main if it starts with ::.
9137 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
9139 # Save the break type for this sub.
9140 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
9141 } ## end elsif ($cmd =~ ...
9143 # b <sub name> [<condition>]
9144 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
9146 my $cond = length $2 ? $2 : '1';
9147 &cmd_b_sub( $subname, $cond );
9150 # b <line> [<condition>].
9151 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9152 my $i = $1 || $dbline;
9153 my $cond = length $2 ? $2 : '1';
9154 &cmd_b_line( $i, $cond );
9156 } ## end sub cmd_pre580_b
9158 =head2 Old C<D> command.
9160 Delete all breakpoints unconditionally.
9167 if ( $cmd =~ /^\s*$/ ) {
9168 print $OUT "Deleting all breakpoints...\n";
9170 # %had_breakpoints lists every file that had at least one
9173 for $file ( keys %had_breakpoints ) {
9175 # Switch to the desired file temporarily.
9176 local *dbline = $main::{ '_<' . $file };
9181 # For all lines in this file ...
9182 for ( $i = 1 ; $i <= $max ; $i++ ) {
9184 # If there's a breakpoint or action on this line ...
9185 if ( defined $dbline{$i} ) {
9187 # ... remove the breakpoint.
9188 $dbline{$i} =~ s/^[^\0]+//;
9189 if ( $dbline{$i} =~ s/^\0?$// ) {
9191 # Remove the entry altogether if no action is there.
9194 } ## end if (defined $dbline{$i...
9195 } ## end for ($i = 1 ; $i <= $max...
9197 # If, after we turn off the "there were breakpoints in this file"
9198 # bit, the entry in %had_breakpoints for this file is zero,
9199 # we should remove this file from the hash.
9200 if ( not $had_breakpoints{$file} &= ~1 ) {
9201 delete $had_breakpoints{$file};
9203 } ## end for $file (keys %had_breakpoints)
9205 # Kill off all the other breakpoints that are waiting for files that
9206 # haven't been loaded yet.
9208 undef %postponed_file;
9209 undef %break_on_load;
9210 } ## end if ($cmd =~ /^\s*$/)
9211 } ## end sub cmd_pre580_D
9213 =head2 Old C<h> command
9215 Print help. Defaults to printing the long-form help; the 5.8 version
9216 prints the summary by default.
9224 # Print the *right* help, long format.
9225 if ( $cmd =~ /^\s*$/ ) {
9226 print_help($pre580_help);
9229 # 'h h' - explicitly-requested summary.
9230 elsif ( $cmd =~ /^h\s*/ ) {
9231 print_help($pre580_summary);
9234 # Find and print a command's help.
9235 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
9236 my $asked = $1; # for proper errmsg
9237 my $qasked = quotemeta($asked); # for searching
9238 # XXX: finds CR but not <CR>
9242 (?:[IB]<) # Optional markup
9243 $qasked # The command name
9250 ( # The command help:
9252 (?:[IB]<) # Optional markup
9253 $qasked # The command name
9254 ([\s\S]*?) # Lines starting with tabs
9258 ) # Line not starting with space
9259 # (Next command's help)
9263 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
9267 print_help("B<$asked> is not a debugger command.\n");
9269 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
9270 } ## end sub cmd_pre580_h
9272 =head2 Old C<W> command
9274 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
9282 # Delete all watch expressions.
9283 if ( $cmd =~ /^$/ ) {
9285 # No watching is going on.
9288 # Kill all the watch expressions and values.
9289 @to_watch = @old_watch = ();
9292 # Add a watch expression.
9293 elsif ( $cmd =~ /^(.*)/s ) {
9295 # add it to the list to be watched.
9298 # Get the current value of the expression.
9299 # Doesn't handle expressions returning list values!
9302 $val = ( defined $val ) ? "'$val'" : 'undef';
9305 push @old_watch, $val;
9307 # We're watching stuff.
9310 } ## end elsif ($cmd =~ /^(.*)/s)
9311 } ## end sub cmd_pre580_W
9313 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
9315 The debugger used to have a bunch of nearly-identical code to handle
9316 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
9317 C<cmd_prepost> unify all this into one set of code to handle the
9318 appropriate actions.
9320 =head2 C<cmd_pre590_prepost>
9322 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
9323 do something destructive. In pre 5.8 debuggers, the default action was to
9324 delete all the actions.
9328 sub cmd_pre590_prepost {
9330 my $line = shift || '*';
9333 return &cmd_prepost( $cmd, $line, $dbline );
9334 } ## end sub cmd_pre590_prepost
9336 =head2 C<cmd_prepost>
9338 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
9339 Since the lists of actions are all held in arrays that are pointed to by
9340 references anyway, all we have to do is pick the right array reference and
9341 then use generic code to all, delete, or list actions.
9348 # No action supplied defaults to 'list'.
9349 my $line = shift || '?';
9351 # Figure out what to put in the prompt.
9354 # Make sure we have some array or another to address later.
9355 # This means that if ssome reason the tests fail, we won't be
9356 # trying to stash actions or delete them from the wrong place.
9359 # < - Perl code to run before prompt.
9360 if ( $cmd =~ /^\</o ) {
9361 $which = 'pre-perl';
9365 # > - Perl code to run after prompt.
9366 elsif ( $cmd =~ /^\>/o ) {
9367 $which = 'post-perl';
9371 # { - first check for properly-balanced braces.
9372 elsif ( $cmd =~ /^\{/o ) {
9373 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
9375 "$cmd is now a debugger command\nuse `;$cmd' if you mean Perl code\n";
9378 # Properly balanced. Pre-prompt debugger actions.
9380 $which = 'pre-debugger';
9383 } ## end elsif ( $cmd =~ /^\{/o )
9385 # Did we find something that makes sense?
9387 print $OUT "Confused by command: $cmd\n";
9394 if ( $line =~ /^\s*\?\s*$/o ) {
9397 # Nothing there. Complain.
9398 print $OUT "No $which actions.\n";
9402 # List the actions in the selected list.
9403 print $OUT "$which commands:\n";
9404 foreach my $action (@$aref) {
9405 print $OUT "\t$cmd -- $action\n";
9408 } ## end if ( $line =~ /^\s*\?\s*$/o)
9410 # Might be a delete.
9412 if ( length($cmd) == 1 ) {
9413 if ( $line =~ /^\s*\*\s*$/o ) {
9415 # It's a delete. Get rid of the old actions in the
9418 print $OUT "All $cmd actions cleared.\n";
9422 # Replace all the actions. (This is a <, >, or {).
9423 @$aref = action($line);
9425 } ## end if ( length($cmd) == 1)
9426 elsif ( length($cmd) == 2 ) {
9428 # Add the action to the line. (This is a <<, >>, or {{).
9429 push @$aref, action($line);
9433 # <<<, >>>>, {{{{{{ ... something not a command.
9435 "Confused by strange length of $which command($cmd)...\n";
9437 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
9439 } ## end sub cmd_prepost
9443 Contains the C<at_exit> routine that the debugger uses to issue the
9444 C<Debugged program terminated ...> message after the program completes. See
9445 the C<END> block documentation for more details.
9452 "Debugged program terminated. Use `q' to quit or `R' to restart.";
9455 package DB; # Do not trace this 1; below!