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>
177 via glob assignment) contains the text from C<$filename>, with each
178 element corresponding to a single line of C<$filename>. Additionally,
179 breakable lines will be dualvars with the numeric component being the
180 memory address of a COP node. Non-breakable lines are dualvar to 0.
182 The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
183 assignment) contains breakpoints and actions. The keys are line numbers;
184 you can set individual values, but not the whole hash. The Perl interpreter
185 uses this hash to determine where breakpoints have been set. Any true value is
186 considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
187 Values are magical in numeric context: 1 if the line is breakable, 0 if not.
189 The scalar C<${"_<$filename"}> simply contains the string C<_<$filename>.
190 This is also the case for evaluated strings that contain subroutines, or
191 which are currently being executed. The $filename for C<eval>ed strings looks
192 like C<(eval 34)> or C<(re_eval 19)>.
194 =head1 DEBUGGER STARTUP
196 When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
197 non-interactive sessions, C<.perldb> for interactive ones) that can set a number
198 of options. In addition, this file may define a subroutine C<&afterinit>
199 that will be executed (in the debugger's context) after the debugger has
202 Next, it checks the C<PERLDB_OPTS> environment variable and treats its
203 contents as the argument of a C<o> command in the debugger.
205 =head2 STARTUP-ONLY OPTIONS
207 The following options can only be specified at startup.
208 To set them in your rcfile, add a call to
209 C<&parse_options("optionName=new_value")>.
215 the TTY to use for debugging i/o.
219 if set, goes in NonStop mode. On interrupt, if TTY is not set,
220 uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
221 Term::Rendezvous. Current variant is to have the name of TTY in this
226 if false, a dummy ReadLine is used, so you can debug
227 ReadLine applications.
231 if true, no i/o is performed until interrupt.
235 file or pipe to print line number info to. If it is a
236 pipe, a short "emacs like" message is used.
240 host:port to connect to on remote host for remote debugging.
244 file to store session history to. There is no default and so no
245 history file is written unless this variable is explicitly set.
249 number of commands to store to the file specified in C<HistFile>.
256 &parse_options("NonStop=1 LineInfo=db.out");
257 sub afterinit { $trace = 1; }
259 The script will run without human intervention, putting trace
260 information into C<db.out>. (If you interrupt it, you had better
261 reset C<LineInfo> to something I<interactive>!)
263 =head1 INTERNALS DESCRIPTION
265 =head2 DEBUGGER INTERFACE VARIABLES
267 Perl supplies the values for C<%sub>. It effectively inserts
268 a C<&DB::DB();> in front of each place that can have a
269 breakpoint. At each subroutine call, it calls C<&DB::sub> with
270 C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
271 {require 'perl5db.pl'}> before the first line.
273 After each C<require>d file is compiled, but before it is executed, a
274 call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
275 is the expanded name of the C<require>d file (as found via C<%INC>).
277 =head3 IMPORTANT INTERNAL VARIABLES
281 Used to control when the debugger will attempt to acquire another TTY to be
286 =item * 1 - on C<fork()>
288 =item * 2 - debugger is started inside debugger
290 =item * 4 - on startup
296 The value -2 indicates that no return value should be printed.
297 Any other positive value causes C<DB::sub> to print return values.
301 The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
302 contents of C<@_> when C<DB::eval> is called.
306 Determines what messages (if any) will get printed when a subroutine (or eval)
307 is entered or exited.
311 =item * 0 - No enter/exit messages
313 =item * 1 - Print I<entering> messages on subroutine entry
315 =item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
317 =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.
319 =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.
321 =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.
325 To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
326 The debugger internally juggles the value of C<$frame> during execution to
327 protect external modules that the debugger uses from getting traced.
331 Tracks current debugger nesting level. Used to figure out how many
332 C<E<lt>E<gt>> pairs to surround the line number with when the debugger
333 outputs a prompt. Also used to help determine if the program has finished
334 during command parsing.
336 =head4 C<$onetimeDump>
338 Controls what (if anything) C<DB::eval()> will print after evaluating an
343 =item * C<undef> - don't print anything
345 =item * C<dump> - use C<dumpvar.pl> to display the value returned
347 =item * C<methods> - print the methods callable on the first item returned
351 =head4 C<$onetimeDumpDepth>
353 Controls how far down C<dumpvar.pl> will go before printing C<...> while
354 dumping a structure. Numeric. If C<undef>, print all levels.
358 Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
359 which is called before every statement, checks this and puts the user into
360 command mode if it finds C<$signal> set to a true value.
364 Controls behavior during single-stepping. Stacked in C<@stack> on entry to
365 each subroutine; popped again at the end of each subroutine.
369 =item * 0 - run continuously.
371 =item * 1 - single-step, go into subs. The C<s> command.
373 =item * 2 - single-step, don't go into subs. The C<n> command.
375 =item * 4 - print current sub depth (turned on to force this when C<too much
382 Controls the output of trace information.
386 =item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
388 =item * 2 - watch expressions are active
390 =item * 4 - user defined a C<watchfunction()> in C<afterinit()>
394 =head4 C<$slave_editor>
396 1 if C<LINEINFO> was directed to a pipe; 0 otherwise.
400 Stack of filehandles that C<DB::readline()> will read commands from.
401 Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
405 Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
406 supplied by the Perl interpreter to the debugger. Contains the source.
410 Previous values of watch expressions. First set when the expression is
411 entered; reset whenever the watch expression changes.
415 Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
416 so that the debugger can substitute safe values while it's running, and
417 restore them when it returns control.
421 Saves the current value of C<$single> on entry to a subroutine.
422 Manipulated by the C<c> command to turn off tracing in all subs above the
427 The 'watch' expressions: to be evaluated before each line is executed.
431 The typeahead buffer, used by C<DB::readline>.
435 Command aliases. Stored as character strings to be substituted for a command
438 =head4 C<%break_on_load>
440 Keys are file names, values are 1 (break when this file is loaded) or undef
441 (don't break when it is loaded).
445 Keys are line numbers, values are C<condition\0action>. If used in numeric
446 context, values are 0 if not breakable, 1 if breakable, no matter what is
447 in the actual hash entry.
449 =head4 C<%had_breakpoints>
451 Keys are file names; values are bitfields:
455 =item * 1 - file has a breakpoint in it.
457 =item * 2 - file has an action in it.
461 A zero or undefined value means this file has neither.
465 Stores the debugger options. These are character string values.
469 Saves breakpoints for code that hasn't been compiled yet.
470 Keys are subroutine names, values are:
474 =item * C<compile> - break when this sub is compiled
476 =item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
480 =head4 C<%postponed_file>
482 This hash keeps track of breakpoints that need to be set for files that have
483 not yet been compiled. Keys are filenames; values are references to hashes.
484 Each of these hashes is keyed by line number, and its values are breakpoint
485 definitions (C<condition\0action>).
487 =head1 DEBUGGER INITIALIZATION
489 The debugger's initialization actually jumps all over the place inside this
490 package. This is because there are several BEGIN blocks (which of course
491 execute immediately) spread through the code. Why is that?
493 The debugger needs to be able to change some things and set some things up
494 before the debugger code is compiled; most notably, the C<$deep> variable that
495 C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
496 debugger has to turn off warnings while the debugger code is compiled, but then
497 restore them to their original setting before the program being debugged begins
500 The first C<BEGIN> block simply turns off warnings by saving the current
501 setting of C<$^W> and then setting it to zero. The second one initializes
502 the debugger variables that are needed before the debugger begins executing.
503 The third one puts C<$^X> back to its former value.
505 We'll detail the second C<BEGIN> block later; just remember that if you need
506 to initialize something before the debugger starts really executing, that's
513 BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
517 $^V =~ /^v(\d+\.\d+)/;
518 feature->import(":$1");
521 # Debugger for Perl 5.00x; perl5db.pl patch level:
524 $header = "perl5db.pl version $VERSION";
526 =head1 DEBUGGER ROUTINES
530 This function replaces straight C<eval()> inside the debugger; it simplifies
531 the process of evaluating code in the user's context.
533 The code to be evaluated is passed via the package global variable
534 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
536 Before we do the C<eval()>, we preserve the current settings of C<$trace>,
537 C<$single>, C<$^D> and C<$usercontext>. The latter contains the
538 preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
539 user's current package, grabbed when C<DB::DB> got control. This causes the
540 proper context to be used when the eval is actually done. Afterward, we
541 restore C<$trace>, C<$single>, and C<$^D>.
543 Next we need to handle C<$@> without getting confused. We save C<$@> in a
544 local lexical, localize C<$saved[0]> (which is where C<save()> will put
545 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
546 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
547 considered sane by the debugger. If there was an C<eval()> error, we print
548 it on the debugger's output. If C<$onetimedump> is defined, we call
549 C<dumpit> if it's set to 'dump', or C<methods> if it's set to
550 'methods'. Setting it to something else causes the debugger to do the eval
551 but not print the result - handy if you want to do something else with it
552 (the "watch expressions" code does this to get the value of the watch
553 expression but not show it unless it matters).
555 In any case, we then return the list of output from C<eval> to the caller,
556 and unwinding restores the former version of C<$@> in C<@saved> as well
557 (the localization of C<$saved[0]> goes away at the end of this scope).
559 =head3 Parameters and variables influencing execution of DB::eval()
561 C<DB::eval> isn't parameterized in the standard way; this is to keep the
562 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
563 The variables listed below influence C<DB::eval()>'s execution directly.
567 =item C<$evalarg> - the thing to actually be eval'ed
569 =item C<$trace> - Current state of execution tracing
571 =item C<$single> - Current state of single-stepping
573 =item C<$onetimeDump> - what is to be displayed after the evaluation
575 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
579 The following variables are altered by C<DB::eval()> during its execution. They
580 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
584 =item C<@res> - used to capture output from actual C<eval>.
586 =item C<$otrace> - saved value of C<$trace>.
588 =item C<$osingle> - saved value of C<$single>.
590 =item C<$od> - saved value of C<$^D>.
592 =item C<$saved[0]> - saved value of C<$@>.
594 =item $\ - for output of C<$@> if there is an evaluation error.
598 =head3 The problem of lexicals
600 The context of C<DB::eval()> presents us with some problems. Obviously,
601 we want to be 'sandboxed' away from the debugger's internals when we do
602 the eval, but we need some way to control how punctuation variables and
603 debugger globals are used.
605 We can't use local, because the code inside C<DB::eval> can see localized
606 variables; and we can't use C<my> either for the same reason. The code
607 in this routine compromises and uses C<my>.
609 After this routine is over, we don't have user code executing in the debugger's
610 context, so we can use C<my> freely.
614 ############################################## Begin lexical danger zone
616 # 'my' variables used here could leak into (that is, be visible in)
617 # the context that the code being evaluated is executing in. This means that
618 # the code could modify the debugger's variables.
620 # Fiddling with the debugger's context could be Bad. We insulate things as
625 # 'my' would make it visible from user code
626 # but so does local! --tchrist
627 # Remember: this localizes @DB::res, not @main::res.
631 # Try to keep the user code from messing with us. Save these so that
632 # even if the eval'ed code changes them, we can put them back again.
633 # Needed because the user could refer directly to the debugger's
634 # package globals (and any 'my' variables in this containing scope)
635 # inside the eval(), and we want to try to stay safe.
636 local $otrace = $trace;
637 local $osingle = $single;
640 # Untaint the incoming eval() argument.
641 { ($evalarg) = $evalarg =~ /(.*)/s; }
643 # $usercontext built in DB::DB near the comment
644 # "set up the context for DB::eval ..."
645 # Evaluate and save any results.
646 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
648 # Restore those old values.
654 # Save the current value of $@, and preserve it in the debugger's copy
655 # of the saved precious globals.
658 # Since we're only saving $@, we only have to localize the array element
659 # that it will be stored in.
660 local $saved[0]; # Preserve the old value of $@
663 # Now see whether we need to report an error back to the user.
669 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
670 # are package globals.
671 elsif ($onetimeDump) {
672 if ( $onetimeDump eq 'dump' ) {
673 local $option{dumpDepth} = $onetimedumpDepth
674 if defined $onetimedumpDepth;
675 dumpit( $OUT, \@res );
677 elsif ( $onetimeDump eq 'methods' ) {
680 } ## end elsif ($onetimeDump)
684 ############################################## End lexical danger zone
686 # After this point it is safe to introduce lexicals.
687 # The code being debugged will be executing in its own context, and
688 # can't see the inside of the debugger.
690 # However, one should not overdo it: leave as much control from outside as
691 # possible. If you make something a lexical, it's not going to be addressable
692 # from outside the debugger even if you know its name.
694 # This file is automatically included if you do perl -d.
695 # It's probably not useful to include this yourself.
697 # Before venturing further into these twisty passages, it is
698 # wise to read the perldebguts man page or risk the ire of dragons.
700 # (It should be noted that perldebguts will tell you a lot about
701 # the underlying mechanics of how the debugger interfaces into the
702 # Perl interpreter, but not a lot about the debugger itself. The new
703 # comments in this code try to address this problem.)
705 # Note that no subroutine call is possible until &DB::sub is defined
706 # (for subroutines defined outside of the package DB). In fact the same is
707 # true if $deep is not defined.
709 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
711 # modified Perl debugger, to be run from Emacs in perldb-mode
712 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
713 # Johan Vromans -- upgrade to 4.0 pl 10
714 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
715 ########################################################################
717 =head1 DEBUGGER INITIALIZATION
719 The debugger starts up in phases.
723 First, it initializes the environment it wants to run in: turning off
724 warnings during its own compilation, defining variables which it will need
725 to avoid warnings later, setting itself up to not exit when the program
726 terminates, and defaulting to printing return values for the C<r> command.
730 # Needed for the statement after exec():
732 # This BEGIN block is simply used to switch off warnings during debugger
733 # compilation. Probably it would be better practice to fix the warnings,
734 # but this is how it's done at the moment.
739 } # Switch compilation warnings off until another BEGIN.
741 local ($^W) = 0; # Switch run-time warnings off during init.
743 =head2 THREADS SUPPORT
745 If we are running under a threaded Perl, we require threads and threads::shared
746 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
747 threaded debugger control. C<-dt> can also be used to set this.
749 Each new thread will be announced and the debugger prompt will always inform
750 you of each new thread created. It will also indicate the thread id in which
751 we are currently running within the prompt like this:
755 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
756 command prompt. The prompt will show: C<[0]> when running under threads, but
757 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
759 While running under threads, when you set or delete a breakpoint (etc.), this
760 will apply to all threads, not just the currently running one. When you are
761 in a currently executing thread, you will stay there until it completes. With
762 the current implementation it is not currently possible to hop from one thread
765 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
767 Note that threading support was built into the debugger as of Perl version
768 C<5.8.6> and debugger version C<1.2.8>.
773 # ensure we can share our non-threaded variables or no-op
774 if ($ENV{PERL5DB_THREADED}) {
776 require threads::shared;
777 import threads::shared qw(share);
781 print "Threads support enabled\n";
788 # This would probably be better done with "use vars", but that wasn't around
789 # when this code was originally written. (Neither was "use strict".) And on
790 # the principle of not fiddling with something that was working, this was
793 # These variables control the execution of 'dumpvar.pl'.
795 $dumpvar::arrayDepth,
796 $dumpvar::dumpDBFiles,
797 $dumpvar::dumpPackages,
798 $dumpvar::quoteHighBit,
799 $dumpvar::printUndef,
803 # used to save @ARGV and extract any debugger-related flags.
806 # used to control die() reporting in diesignal()
809 # used to prevent multiple entries to diesignal()
810 # (if for instance diesignal() itself dies)
813 # used to prevent the debugger from running nonstop
819 # without threads, $filename is not defined until DB::DB is called
820 foreach my $k (keys (%INC)) {
821 &share(\$main::{'_<'.$filename}) if defined $filename;
824 # Command-line + PERLLIB:
825 # Save the contents of @INC before they are modified elsewhere.
828 # This was an attempt to clear out the previous values of various
829 # trapped errors. Apparently it didn't help. XXX More info needed!
830 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
832 # We set these variables to safe values. We don't want to blindly turn
833 # off warnings, because other packages may still want them.
834 $trace = $signal = $single = 0; # Uninitialized warning suppression
835 # (local $^W cannot help - other packages!).
837 # Default to not exiting when program finishes; print the return
838 # value when the 'r' command is used to return from a subroutine.
839 $inhibit_exit = $option{PrintRet} = 1;
841 # Default to 1 so the prompt will display the first line.
844 =head1 OPTION PROCESSING
846 The debugger's options are actually spread out over the debugger itself and
847 C<dumpvar.pl>; some of these are variables to be set, while others are
848 subs to be called with a value. To try to make this a little easier to
849 manage, the debugger uses a few data structures to define what options
850 are legal and how they are to be processed.
852 First, the C<@options> array defines the I<names> of all the options that
858 CommandSet HistFile HistSize
859 hashDepth arrayDepth dumpDepth
860 DumpDBFiles DumpPackages DumpReused
861 compactDump veryCompact quote
862 HighBit undefPrint globPrint
863 PrintRet UsageOnly frame
865 ReadLine NonStop LineInfo
866 maxTraceLen recallCommand ShellBang
867 pager tkRunning ornaments
868 signalLevel warnLevel dieLevel
869 inhibit_exit ImmediateStop bareStringify
870 CreateTTY RemotePort windowSize
874 @RememberOnROptions = qw(DollarCaretP);
878 Second, C<optionVars> lists the variables that each option uses to save its
884 hashDepth => \$dumpvar::hashDepth,
885 arrayDepth => \$dumpvar::arrayDepth,
886 CommandSet => \$CommandSet,
887 DumpDBFiles => \$dumpvar::dumpDBFiles,
888 DumpPackages => \$dumpvar::dumpPackages,
889 DumpReused => \$dumpvar::dumpReused,
890 HighBit => \$dumpvar::quoteHighBit,
891 undefPrint => \$dumpvar::printUndef,
892 globPrint => \$dumpvar::globPrint,
893 UsageOnly => \$dumpvar::usageOnly,
894 CreateTTY => \$CreateTTY,
895 bareStringify => \$dumpvar::bareStringify,
897 AutoTrace => \$trace,
898 inhibit_exit => \$inhibit_exit,
899 maxTraceLen => \$maxtrace,
900 ImmediateStop => \$ImmediateStop,
901 RemotePort => \$remoteport,
902 windowSize => \$window,
903 HistFile => \$histfile,
904 HistSize => \$histsize,
909 Third, C<%optionAction> defines the subroutine to be called to process each
915 compactDump => \&dumpvar::compactDump,
916 veryCompact => \&dumpvar::veryCompact,
917 quote => \&dumpvar::quote,
920 ReadLine => \&ReadLine,
921 NonStop => \&NonStop,
922 LineInfo => \&LineInfo,
923 recallCommand => \&recallCommand,
924 ShellBang => \&shellBang,
926 signalLevel => \&signalLevel,
927 warnLevel => \&warnLevel,
928 dieLevel => \&dieLevel,
929 tkRunning => \&tkRunning,
930 ornaments => \&ornaments,
931 RemotePort => \&RemotePort,
932 DollarCaretP => \&DollarCaretP,
937 Last, the C<%optionRequire> notes modules that must be C<require>d if an
942 # Note that this list is not complete: several options not listed here
943 # actually require that dumpvar.pl be loaded for them to work, but are
944 # not in the table. A subsequent patch will correct this problem; for
945 # the moment, we're just recommenting, and we are NOT going to change
948 compactDump => 'dumpvar.pl',
949 veryCompact => 'dumpvar.pl',
950 quote => 'dumpvar.pl',
955 There are a number of initialization-related variables which can be set
956 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
961 =item C<$rl> - readline control XXX needs more explanation
963 =item C<$warnLevel> - whether or not debugger takes over warning handling
965 =item C<$dieLevel> - whether or not debugger takes over die handling
967 =item C<$signalLevel> - whether or not debugger takes over signal handling
969 =item C<$pre> - preprompt actions (array reference)
971 =item C<$post> - postprompt actions (array reference)
975 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
977 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
983 # These guys may be defined in $ENV{PERL5DB} :
984 $rl = 1 unless defined $rl;
985 $warnLevel = 1 unless defined $warnLevel;
986 $dieLevel = 1 unless defined $dieLevel;
987 $signalLevel = 1 unless defined $signalLevel;
988 $pre = [] unless defined $pre;
989 $post = [] unless defined $post;
990 $pretype = [] unless defined $pretype;
991 $CreateTTY = 3 unless defined $CreateTTY;
992 $CommandSet = '580' unless defined $CommandSet;
1007 The default C<die>, C<warn>, and C<signal> handlers are set up.
1011 warnLevel($warnLevel);
1012 dieLevel($dieLevel);
1013 signalLevel($signalLevel);
1017 The pager to be used is needed next. We try to get it from the
1018 environment first. If it's not defined there, we try to find it in
1019 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1020 then call the C<pager()> function to save the pager name.
1024 # This routine makes sure $pager is set up so that '|' can use it.
1027 # If PAGER is defined in the environment, use it.
1031 # If not, see if Config.pm defines it.
1032 : eval { require Config }
1033 && defined $Config::Config{pager}
1034 ? $Config::Config{pager}
1036 # If not, fall back to 'more'.
1039 unless defined $pager;
1043 We set up the command to be used to access the man pages, the command
1044 recall character (C<!> unless otherwise defined) and the shell escape
1045 character (C<!> unless otherwise defined). Yes, these do conflict, and
1046 neither works in the debugger at the moment.
1052 # Set up defaults for command recall and shell escape (note:
1053 # these currently don't work in linemode debugging).
1054 &recallCommand("!") unless defined $prc;
1055 &shellBang("!") unless defined $psh;
1059 We then set up the gigantic string containing the debugger help.
1060 We also set the limit on the number of arguments we'll display during a
1067 # If we didn't get a default for the length of eval/stack trace args,
1069 $maxtrace = 400 unless defined $maxtrace;
1071 =head2 SETTING UP THE DEBUGGER GREETING
1073 The debugger I<greeting> helps to inform the user how many debuggers are
1074 running, and whether the current debugger is the primary or a child.
1076 If we are the primary, we just hang onto our pid so we'll have it when
1077 or if we start a child debugger. If we are a child, we'll set things up
1078 so we'll have a unique greeting and so the parent will give us our own
1081 We save the current contents of the C<PERLDB_PIDS> environment variable
1082 because we mess around with it. We'll also need to hang onto it because
1083 we'll need it if we restart.
1085 Child debuggers make a label out of the current PID structure recorded in
1086 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1087 yet so the parent will give them one later via C<resetterm()>.
1091 # Save the current contents of the environment; we're about to
1092 # much with it. We'll need this if we have to restart.
1093 $ini_pids = $ENV{PERLDB_PIDS};
1095 if ( defined $ENV{PERLDB_PIDS} ) {
1097 # We're a child. Make us a label out of the current PID structure
1098 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1099 # a term yet so the parent will give us one later via resetterm().
1101 my $env_pids = $ENV{PERLDB_PIDS};
1102 $pids = "[$env_pids]";
1104 # Unless we are on OpenVMS, all programs under the DCL shell run under
1107 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1111 $ENV{PERLDB_PIDS} .= "->$$";
1115 } ## end if (defined $ENV{PERLDB_PIDS...
1118 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1119 # child debugger, and mark us as the parent, so we'll know to set up
1120 # more TTY's is we have to.
1121 $ENV{PERLDB_PIDS} = "$$";
1128 # Sets up $emacs as a synonym for $slave_editor.
1129 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1131 =head2 READING THE RC FILE
1133 The debugger will read a file of initialization options if supplied. If
1134 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1138 # As noted, this test really doesn't check accurately that the debugger
1139 # is running at a terminal or not.
1141 my $dev_tty = '/dev/tty';
1142 $dev_tty = 'TT:' if ($^O eq 'VMS');
1143 if ( -e $dev_tty ) { # this is the wrong metric!
1144 $rcfile = ".perldb";
1147 $rcfile = "perldb.ini";
1152 The debugger does a safety test of the file to be read. It must be owned
1153 either by the current user or root, and must only be writable by the owner.
1157 # This wraps a safety test around "do" to read and evaluate the init file.
1159 # This isn't really safe, because there's a race
1160 # between checking and opening. The solution is to
1161 # open and fstat the handle, but then you have to read and
1162 # eval the contents. But then the silly thing gets
1163 # your lexical scope, which is unfortunate at best.
1167 # Just exactly what part of the word "CORE::" don't you understand?
1168 local $SIG{__WARN__};
1169 local $SIG{__DIE__};
1171 unless ( is_safe_file($file) ) {
1172 CORE::warn <<EO_GRIPE;
1173 perldb: Must not source insecure rcfile $file.
1174 You or the superuser must be the owner, and it must not
1175 be writable by anyone but its owner.
1178 } ## end unless (is_safe_file($file...
1181 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1182 } ## end sub safe_do
1184 # This is the safety test itself.
1186 # Verifies that owner is either real user or superuser and that no
1187 # one but owner may write to it. This function is of limited use
1188 # when called on a path instead of upon a handle, because there are
1189 # no guarantees that filename (by dirent) whose file (by ino) is
1190 # eventually accessed is the same as the one tested.
1191 # Assumes that the file's existence is not in doubt.
1194 stat($path) || return; # mysteriously vaporized
1195 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1197 return 0 if $uid != 0 && $uid != $<;
1198 return 0 if $mode & 022;
1200 } ## end sub is_safe_file
1202 # If the rcfile (whichever one we decided was the right one to read)
1203 # exists, we safely do it.
1205 safe_do("./$rcfile");
1208 # If there isn't one here, try the user's home directory.
1209 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1210 safe_do("$ENV{HOME}/$rcfile");
1213 # Else try the login directory.
1214 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1215 safe_do("$ENV{LOGDIR}/$rcfile");
1218 # If the PERLDB_OPTS variable has options in it, parse those out next.
1219 if ( defined $ENV{PERLDB_OPTS} ) {
1220 parse_options( $ENV{PERLDB_OPTS} );
1225 The last thing we do during initialization is determine which subroutine is
1226 to be used to obtain a new terminal when a new debugger is started. Right now,
1227 the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
1232 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1233 # Works if you're running an xterm or xterm-like window, or you're on
1234 # OS/2, or on Mac OS X. This may need some expansion.
1236 if (not defined &get_fork_TTY) # only if no routine exists
1238 if ( defined $remoteport ) {
1239 # Expect an inetd-like server
1240 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1242 elsif (defined $ENV{TERM} # If we know what kind
1243 # of terminal this is,
1244 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1245 and defined $ENV{DISPLAY} # and what display it's on,
1248 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1250 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1251 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1253 elsif ( $^O eq 'darwin' # If this is Mac OS X
1254 and defined $ENV{TERM_PROGRAM} # and we're running inside
1255 and $ENV{TERM_PROGRAM}
1256 eq 'Apple_Terminal' # Terminal.app
1259 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1261 } ## end if (not defined &get_fork_TTY...
1263 # untaint $^O, which may have been tainted by the last statement.
1264 # see bug [perl #24674]
1268 # Here begin the unreadable code. It needs fixing.
1270 =head2 RESTART PROCESSING
1272 This section handles the restart command. When the C<R> command is invoked, it
1273 tries to capture all of the state it can into environment variables, and
1274 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1275 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1276 the R command stuffed into the environment variables.
1278 PERLDB_RESTART - flag only, contains no restart data itself.
1279 PERLDB_HIST - command history, if it's available
1280 PERLDB_ON_LOAD - breakpoints set by the rc file
1281 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1282 PERLDB_VISITED - files that had breakpoints
1283 PERLDB_FILE_... - breakpoints for a file
1284 PERLDB_OPT - active options
1285 PERLDB_INC - the original @INC
1286 PERLDB_PRETYPE - preprompt debugger actions
1287 PERLDB_PRE - preprompt Perl code
1288 PERLDB_POST - post-prompt Perl code
1289 PERLDB_TYPEAHEAD - typeahead captured by readline()
1291 We chug through all these variables and plug the values saved in them
1292 back into the appropriate spots in the debugger.
1296 if ( exists $ENV{PERLDB_RESTART} ) {
1298 # We're restarting, so we don't need the flag that says to restart anymore.
1299 delete $ENV{PERLDB_RESTART};
1302 @hist = get_list('PERLDB_HIST');
1303 %break_on_load = get_list("PERLDB_ON_LOAD");
1304 %postponed = get_list("PERLDB_POSTPONE");
1308 share(%break_on_load);
1311 # restore breakpoints/actions
1312 my @had_breakpoints = get_list("PERLDB_VISITED");
1313 for my $file_idx ( 0 .. $#had_breakpoints ) {
1314 my $filename = $had_breakpoints[$file_idx];
1315 my %pf = get_list("PERLDB_FILE_$file_idx");
1316 $postponed_file{ $filename } = \%pf if %pf;
1317 my @lines = sort {$a <=> $b} keys(%pf);
1318 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1319 for my $line_idx (0 .. $#lines) {
1320 _set_breakpoint_enabled_status(
1323 ($enabled_statuses[$line_idx] ? 1 : ''),
1329 my %opt = get_list("PERLDB_OPT");
1331 while ( ( $opt, $val ) = each %opt ) {
1332 $val =~ s/[\\\']/\\$1/g;
1333 parse_options("$opt'$val'");
1336 # restore original @INC
1337 @INC = get_list("PERLDB_INC");
1340 # return pre/postprompt actions and typeahead buffer
1341 $pretype = [ get_list("PERLDB_PRETYPE") ];
1342 $pre = [ get_list("PERLDB_PRE") ];
1343 $post = [ get_list("PERLDB_POST") ];
1344 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1345 } ## end if (exists $ENV{PERLDB_RESTART...
1347 =head2 SETTING UP THE TERMINAL
1349 Now, we'll decide how the debugger is going to interact with the user.
1350 If there's no TTY, we set the debugger to run non-stop; there's not going
1351 to be anyone there to enter commands.
1362 If there is a TTY, we have to determine who it belongs to before we can
1363 proceed. If this is a slave editor or graphical debugger (denoted by
1364 the first command-line switch being '-emacs'), we shift this off and
1365 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1371 # Is Perl being run from a slave editor or graphical debugger?
1372 # If so, don't use readline, and set $slave_editor = 1.
1374 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1375 $rl = 0, shift(@main::ARGV) if $slave_editor;
1377 #require Term::ReadLine;
1381 We then determine what the console should be on various systems:
1385 =item * Cygwin - We use C<stdin> instead of a separate device.
1389 if ( $^O eq 'cygwin' ) {
1391 # /dev/tty is binary. use stdin for textmode
1395 =item * Unix - use C</dev/tty>.
1399 elsif ( -e "/dev/tty" ) {
1400 $console = "/dev/tty";
1403 =item * Windows or MSDOS - use C<con>.
1407 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1411 =item * VMS - use C<sys$command>.
1417 # everything else is ...
1418 $console = "sys\$command";
1425 Several other systems don't use a specific console. We C<undef $console>
1426 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1427 with a slave editor, Epoc).
1431 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1433 # /dev/tty is binary. use stdin for textmode
1437 if ( $^O eq 'NetWare' ) {
1439 # /dev/tty is binary. use stdin for textmode
1443 # In OS/2, we need to use STDIN to get textmode too, even though
1444 # it pretty much looks like Unix otherwise.
1445 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1450 # EPOC also falls into the 'got to use STDIN' camp.
1451 if ( $^O eq 'epoc' ) {
1457 If there is a TTY hanging around from a parent, we use that as the console.
1461 $console = $tty if defined $tty;
1463 =head2 SOCKET HANDLING
1465 The debugger is capable of opening a socket and carrying out a debugging
1466 session over the socket.
1468 If C<RemotePort> was defined in the options, the debugger assumes that it
1469 should try to start a debugging session on that port. It builds the socket
1470 and then tries to connect the input and output filehandles to it.
1474 # Handle socket stuff.
1476 if ( defined $remoteport ) {
1478 # If RemotePort was defined in the options, connect input and output
1480 $IN = $OUT = connect_remoteport();
1481 } ## end if (defined $remoteport)
1485 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1486 this is probably a situation where multiple debuggers are running (for example,
1487 a backticked command that starts up another debugger). We create a new IN and
1488 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1496 # Two debuggers running (probably a system or a backtick that invokes
1497 # the debugger itself under the running one). create a new IN and OUT
1498 # filehandle, and do the necessary mojo to create a new tty if we
1499 # know how, and we can.
1500 create_IN_OUT(4) if $CreateTTY & 4;
1503 # If we have a console, check to see if there are separate ins and
1504 # outs to open. (They are assumed identical if not.)
1506 my ( $i, $o ) = split /,/, $console;
1507 $o = $i unless defined $o;
1509 # read/write on in, or just read, or read on STDIN.
1511 || open( IN, "<$i" )
1512 || open( IN, "<&STDIN" );
1514 # read/write/create/clobber out, or write/create/clobber out,
1515 # or merge with STDERR, or merge with STDOUT.
1517 || open( OUT, ">$o" )
1518 || open( OUT, ">&STDERR" )
1519 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1521 } ## end if ($console)
1522 elsif ( not defined $console ) {
1524 # No console. Open STDIN.
1525 open( IN, "<&STDIN" );
1527 # merge with STDERR, or with STDOUT.
1528 open( OUT, ">&STDERR" )
1529 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1530 $console = 'STDIN/OUT';
1531 } ## end elsif (not defined $console)
1533 # Keep copies of the filehandles so that when the pager runs, it
1534 # can close standard input without clobbering ours.
1535 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1536 } ## end elsif (from if(defined $remoteport))
1538 # Unbuffer DB::OUT. We need to see responses right away.
1539 my $previous = select($OUT);
1540 $| = 1; # for DB::OUT
1543 # Line info goes to debugger output unless pointed elsewhere.
1544 # Pointing elsewhere makes it possible for slave editors to
1545 # keep track of file and position. We have both a filehandle
1546 # and a I/O description to keep track of.
1547 $LINEINFO = $OUT unless defined $LINEINFO;
1548 $lineinfo = $console unless defined $lineinfo;
1549 # share($LINEINFO); # <- unable to share globs
1554 To finish initialization, we show the debugger greeting,
1555 and then call the C<afterinit()> subroutine if there is one.
1559 # Show the debugger greeting.
1560 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1561 unless ($runnonstop) {
1564 if ( $term_pid eq '-1' ) {
1565 print $OUT "\nDaughter DB session started...\n";
1568 print $OUT "\nLoading DB routines from $header\n";
1571 $slave_editor ? "enabled" : "available", ".\n"
1574 "\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
1575 } ## end else [ if ($term_pid eq '-1')
1576 } ## end unless ($runnonstop)
1577 } ## end else [ if ($notty)
1579 # XXX This looks like a bug to me.
1580 # Why copy to @ARGS and then futz with @args?
1583 # Make sure backslashes before single quotes are stripped out, and
1584 # keep args unless they are numeric (XXX why?)
1585 # s/\'/\\\'/g; # removed while not justified understandably
1586 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1589 # If there was an afterinit() sub defined, call it. It will get
1590 # executed in our scope, so it can fiddle with debugger globals.
1591 if ( defined &afterinit ) { # May be defined in $rcfile
1595 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1598 ############################################################ Subroutines
1604 This gigantic subroutine is the heart of the debugger. Called before every
1605 statement, its job is to determine if a breakpoint has been reached, and
1606 stop if so; read commands from the user, parse them, and execute
1607 them, and then send execution off to the next statement.
1609 Note that the order in which the commands are processed is very important;
1610 some commands earlier in the loop will actually alter the C<$cmd> variable
1611 to create other commands to be executed later. This is all highly I<optimized>
1612 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1613 see what's happening in any given command.
1619 # lock the debugger and get the thread id for the prompt
1622 if ($ENV{PERL5DB_THREADED}) {
1623 $tid = eval { "[".threads->tid."]" };
1626 # Check for whether we should be running continuously or not.
1627 # _After_ the perl program is compiled, $single is set to 1:
1628 if ( $single and not $second_time++ ) {
1630 # Options say run non-stop. Run until we get an interrupt.
1631 if ($runnonstop) { # Disable until signal
1632 # If there's any call stack in place, turn off single
1633 # stepping into subs throughout the stack.
1634 for ( $i = 0 ; $i <= $stack_depth ; ) {
1635 $stack[ $i++ ] &= ~1;
1638 # And we are now no longer in single-step mode.
1641 # If we simply returned at this point, we wouldn't get
1642 # the trace info. Fall on through.
1644 } ## end if ($runnonstop)
1646 elsif ($ImmediateStop) {
1648 # We are supposed to stop here; XXX probably a break.
1649 $ImmediateStop = 0; # We've processed it; turn it off
1650 $signal = 1; # Simulate an interrupt to force
1651 # us into the command loop
1653 } ## end if ($single and not $second_time...
1655 # If we're in single-step mode, or an interrupt (real or fake)
1656 # has occurred, turn off non-stop mode.
1657 $runnonstop = 0 if $single or $signal;
1659 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1660 # The code being debugged may have altered them.
1663 # Since DB::DB gets called after every line, we can use caller() to
1664 # figure out where we last were executing. Sneaky, eh? This works because
1665 # caller is returning all the extra information when called from the
1667 local ( $package, $filename, $line ) = caller;
1668 local $filename_ini = $filename;
1670 # set up the context for DB::eval, so it can properly execute
1671 # code on behalf of the user. We add the package in so that the
1672 # code is eval'ed in the proper package (not in the debugger!).
1673 local $usercontext =
1674 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' . "package $package;";
1676 # Create an alias to the active file magical array to simplify
1678 local (*dbline) = $main::{ '_<' . $filename };
1680 # Last line in the program.
1681 local $max = $#dbline;
1683 # if we have something here, see if we should break.
1685 && _is_breakpoint_enabled($filename, $line)
1686 && ( ( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1689 # Stop if the stop criterion says to just stop.
1690 if ( $stop eq '1' ) {
1694 # It's a conditional stop; eval it in the user's context and
1695 # see if we should stop. If so, remove the one-time sigil.
1697 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1699 # If the breakpoint is temporary, then delete its enabled status.
1700 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1701 _cancel_breakpoint_temp_enabled_status($filename, $line);
1704 } ## end if ($dbline{$line} && ...
1706 # Preserve the current stop-or-not, and see if any of the W
1707 # (watch expressions) has changed.
1708 my $was_signal = $signal;
1710 # If we have any watch expressions ...
1712 for ( my $n = 0 ; $n <= $#to_watch ; $n++ ) {
1713 $evalarg = $to_watch[$n];
1714 local $onetimeDump; # Tell DB::eval() to not output results
1716 # Fix context DB::eval() wants to return an array, but
1717 # we need a scalar here.
1718 my ($val) = join( "', '", &eval );
1719 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
1722 if ( $val ne $old_watch[$n] ) {
1724 # Yep! Show the difference, and fake an interrupt.
1727 Watchpoint $n:\t$to_watch[$n] changed:
1728 old value:\t$old_watch[$n]
1731 $old_watch[$n] = $val;
1732 } ## end if ($val ne $old_watch...
1733 } ## end for (my $n = 0 ; $n <= ...
1734 } ## end if ($trace & 2)
1736 =head2 C<watchfunction()>
1738 C<watchfunction()> is a function that can be defined by the user; it is a
1739 function which will be run on each entry to C<DB::DB>; it gets the
1740 current package, filename, and line as its parameters.
1742 The watchfunction can do anything it likes; it is executing in the
1743 debugger's context, so it has access to all of the debugger's internal
1744 data structures and functions.
1746 C<watchfunction()> can control the debugger's actions. Any of the following
1747 will cause the debugger to return control to the user's program after
1748 C<watchfunction()> executes:
1754 Returning a false value from the C<watchfunction()> itself.
1758 Altering C<$single> to a false value.
1762 Altering C<$signal> to a false value.
1766 Turning off the C<4> bit in C<$trace> (this also disables the
1767 check for C<watchfunction()>. This can be done with
1775 # If there's a user-defined DB::watchfunction, call it with the
1776 # current package, filename, and line. The function executes in
1778 if ( $trace & 4 ) { # User-installed watch
1780 if watchfunction( $package, $filename, $line )
1783 and not( $trace & ~4 );
1784 } ## end if ($trace & 4)
1786 # Pick up any alteration to $signal in the watchfunction, and
1787 # turn off the signal now.
1788 $was_signal = $signal;
1791 =head2 GETTING READY TO EXECUTE COMMANDS
1793 The debugger decides to take control if single-step mode is on, the
1794 C<t> command was entered, or the user generated a signal. If the program
1795 has fallen off the end, we set things up so that entering further commands
1796 won't cause trouble, and we say that the program is over.
1800 # Make sure that we always print if asked for explicitly regardless
1801 # of $trace_to_depth .
1802 my $explicit_stop = ($single || $was_signal);
1804 # Check to see if we should grab control ($single true,
1805 # trace set appropriately, or we got a signal).
1806 if ( $explicit_stop || ( $trace & 1 ) ) {
1808 # Yes, grab control.
1809 if ($slave_editor) {
1811 # Tell the editor to update its position.
1812 $position = "\032\032$filename:$line:0\n";
1813 print_lineinfo($position);
1818 Special check: if we're in package C<DB::fake>, we've gone through the
1819 C<END> block at least once. We set up everything so that we can continue
1820 to enter commands and have a valid context to be in.
1824 elsif ( $package eq 'DB::fake' ) {
1826 # Fallen off the end already.
1829 Debugged program terminated. Use B<q> to quit or B<R> to restart,
1830 use B<o> I<inhibit_exit> to avoid stopping after program termination,
1831 B<h q>, B<h R> or B<h o> to get additional info.
1834 # Set the DB::eval context appropriately.
1837 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;'
1838 . "package $package;"; # this won't let them modify, alas
1839 } ## end elsif ($package eq 'DB::fake')
1843 If the program hasn't finished executing, we scan forward to the
1844 next executable line, print that out, build the prompt from the file and line
1845 number information, and print that.
1852 # Still somewhere in the midst of execution. Set up the
1854 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
1855 # Perl 5 ones (sorry, we don't print Klingon
1858 $prefix = $sub =~ /::/ ? "" : "${'package'}::";
1859 $prefix .= "$sub($filename:";
1860 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" );
1862 # Break up the prompt if it's really long.
1863 if ( length($prefix) > 30 ) {
1864 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
1870 $position = "$prefix$line$infix$dbline[$line]$after";
1873 # Print current line info, indenting if necessary.
1875 print_lineinfo( ' ' x $stack_depth,
1876 "$line:\t$dbline[$line]$after" );
1879 depth_print_lineinfo($explicit_stop, $position);
1882 # Scan forward, stopping at either the end or the next
1884 for ( $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i )
1887 # Drop out on null statements, block closers, and comments.
1888 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
1890 # Drop out if the user interrupted us.
1893 # Append a newline if the line doesn't have one. Can happen
1894 # in eval'ed text, for instance.
1895 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" );
1897 # Next executable line.
1898 $incr_pos = "$prefix$i$infix$dbline[$i]$after";
1899 $position .= $incr_pos;
1902 # Print it indented if tracing is on.
1903 print_lineinfo( ' ' x $stack_depth,
1904 "$i:\t$dbline[$i]$after" );
1907 depth_print_lineinfo($explicit_stop, $incr_pos);
1909 } ## end for ($i = $line + 1 ; $i...
1910 } ## end else [ if ($slave_editor)
1911 } ## end if ($single || ($trace...
1915 If there's an action to be executed for the line we stopped at, execute it.
1916 If there are any preprompt actions, execute those as well.
1920 # If there's an action, do it now.
1921 $evalarg = $action, &eval if $action;
1923 # Are we nested another level (e.g., did we evaluate a function
1924 # that had a breakpoint in it at the debugger prompt)?
1925 if ( $single || $was_signal ) {
1927 # Yes, go down a level.
1928 local $level = $level + 1;
1930 # Do any pre-prompt actions.
1931 foreach $evalarg (@$pre) {
1935 # Complain about too much recursion if we passed the limit.
1936 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
1939 # The line we're currently on. Set $incr to -1 to stay here
1940 # until we get a command that tells us to advance.
1942 $incr = -1; # for backward motion.
1944 # Tack preprompt debugger actions ahead of any actual input.
1945 @typeahead = ( @$pretype, @typeahead );
1947 =head2 WHERE ARE WE?
1949 XXX Relocate this section?
1951 The debugger normally shows the line corresponding to the current line of
1952 execution. Sometimes, though, we want to see the next line, or to move elsewhere
1953 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
1955 C<$incr> controls by how many lines the I<current> line should move forward
1956 after a command is executed. If set to -1, this indicates that the I<current>
1957 line shouldn't change.
1959 C<$start> is the I<current> line. It is used for things like knowing where to
1960 move forwards or backwards from when doing an C<L> or C<-> command.
1962 C<$max> tells the debugger where the last line of the current file is. It's
1963 used to terminate loops most often.
1965 =head2 THE COMMAND LOOP
1967 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
1974 The outer part of the loop, starting at the C<CMD> label. This loop
1975 reads a command and then executes it.
1979 The inner part of the loop, starting at the C<PIPE> label. This part
1980 is wholly contained inside the C<CMD> block and only executes a command.
1981 Used to handle commands running inside a pager.
1985 So why have two labels to restart the loop? Because sometimes, it's easier to
1986 have a command I<generate> another command and then re-execute the loop to do
1987 the new command. This is faster, but perhaps a bit more convoluted.
1991 # The big command dispatch loop. It keeps running until the
1992 # user yields up control again.
1994 # If we have a terminal for input, and we get something back
1995 # from readline(), keep on processing.
1999 # We have a terminal, or can get one ...
2000 ( $term || &setterm ),
2002 # ... and it belogs to this PID or we get one for this PID ...
2003 ( $term_pid == $$ or resetterm(1) ),
2005 # ... and we got a line of command input ...
2008 "$pidprompt $tid DB"
2011 . ( '>' x $level ) . " "
2018 # ... try to execute the input as debugger commands.
2020 # Don't stop running.
2023 # No signal is active.
2026 # Handle continued commands (ending with \):
2027 $cmd =~ s/\\$/\n/ && do {
2028 $cmd .= &readline(" cont: ");
2032 =head4 The null command
2034 A newline entered by itself means I<re-execute the last command>. We grab the
2035 command out of C<$laststep> (where it was recorded previously), and copy it
2036 back into C<$cmd> to be executed below. If there wasn't any previous command,
2037 we'll do nothing below (no command will match). If there was, we also save it
2038 in the command history and fall through to allow the command parsing to pick
2043 # Empty input means repeat the last command.
2044 $cmd =~ /^$/ && ( $cmd = $laststep );
2045 chomp($cmd); # get rid of the annoying extra newline
2046 push( @hist, $cmd ) if length($cmd) > 1;
2047 push( @truehist, $cmd );
2051 # This is a restart point for commands that didn't arrive
2052 # via direct user input. It allows us to 'redo PIPE' to
2053 # re-execute command processing without reading a new command.
2055 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2056 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
2057 ($i) = split( /\s+/, $cmd );
2059 =head3 COMMAND ALIASES
2061 The debugger can create aliases for commands (these are stored in the
2062 C<%alias> hash). Before a command is executed, the command loop looks it up
2063 in the alias hash and substitutes the contents of the alias for the command,
2064 completely replacing it.
2068 # See if there's an alias for the command, and set it up if so.
2071 # Squelch signal handling; we want to keep control here
2072 # if something goes loco during the alias eval.
2073 local $SIG{__DIE__};
2074 local $SIG{__WARN__};
2076 # This is a command, so we eval it in the DEBUGGER's
2077 # scope! Otherwise, we can't see the special debugger
2078 # variables, or get to the debugger's subs. (Well, we
2079 # _could_, but why make it even more complicated?)
2080 eval "\$cmd =~ $alias{$i}";
2083 print $OUT "Couldn't evaluate '$i' alias: $@";
2086 } ## end if ($alias{$i})
2088 =head3 MAIN-LINE COMMANDS
2090 All of these commands work up to and after the program being debugged has
2095 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2096 try to execute further, cleaning any restart-related stuff out of the
2097 environment, and executing with the last value of C<$?>.
2101 $cmd =~ /^q$/ && do {
2107 =head4 C<t> - trace [n]
2109 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2110 If level is specified, set C<$trace_to_depth>.
2114 $cmd =~ /^t(?:\s+(\d+))?$/ && do {
2118 $trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
2119 print $OUT "Trace = "
2121 ? ( $levels ? "on (to level $trace_to_depth)" : "on" )
2126 =head4 C<S> - list subroutines matching/not matching a pattern
2128 Walks through C<%sub>, checking to see whether or not to print the name.
2132 $cmd =~ /^S(\s+(!)?(.+))?$/ && do {
2134 $Srev = defined $2; # Reverse scan?
2135 $Spatt = $3; # The pattern (if any) to use.
2136 $Snocheck = !defined $1; # No args - print all subs.
2138 # Need to make these sane here.
2142 # Search through the debugger's magical hash of subs.
2143 # If $nocheck is true, just print the sub name.
2144 # Otherwise, check it against the pattern. We then use
2145 # the XOR trick to reverse the condition as required.
2146 foreach $subname ( sort( keys %sub ) ) {
2147 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2148 print $OUT $subname, "\n";
2154 =head4 C<X> - list variables in current package
2156 Since the C<V> command actually processes this, just change this to the
2157 appropriate C<V> command and fall through.
2161 $cmd =~ s/^X\b/V $package/;
2163 =head4 C<V> - list variables
2165 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2169 # Bare V commands get the currently-being-debugged package
2171 $cmd =~ /^V$/ && do {
2172 $cmd = "V $package";
2175 # V - show variables in package.
2176 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
2178 # Save the currently selected filehandle and
2179 # force output to debugger's filehandle (dumpvar
2180 # just does "print" for output).
2181 local ($savout) = select($OUT);
2183 # Grab package name and variables to dump.
2185 @vars = split( ' ', $2 );
2187 # If main::dumpvar isn't here, get it.
2188 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
2189 if ( defined &main::dumpvar ) {
2191 # We got it. Turn off subroutine entry/exit messages
2192 # for the moment, along with return values.
2196 # must detect sigpipe failures - not catching
2197 # then will cause the debugger to die.
2201 defined $option{dumpDepth}
2202 ? $option{dumpDepth}
2203 : -1, # assume -1 unless specified
2208 # The die doesn't need to include the $@, because
2209 # it will automatically get propagated for us.
2211 die unless $@ =~ /dumpvar print failed/;
2213 } ## end if (defined &main::dumpvar)
2216 # Couldn't load dumpvar.
2217 print $OUT "dumpvar.pl not available.\n";
2220 # Restore the output filehandle, and go round again.
2225 =head4 C<x> - evaluate and print an expression
2227 Hands the expression off to C<DB::eval>, setting it up to print the value
2228 via C<dumpvar.pl> instead of just printing it directly.
2232 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval()
2233 $onetimeDump = 'dump'; # main::dumpvar shows the output
2235 # handle special "x 3 blah" syntax XXX propagate
2236 # doc back to special variables.
2237 if ( $cmd =~ s/^\s*(\d+)(?=\s)/ / ) {
2238 $onetimedumpDepth = $1;
2242 =head4 C<m> - print methods
2244 Just uses C<DB::methods> to determine what methods are available.
2248 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do {
2253 # m expr - set up DB::eval to do the work
2254 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval()
2255 $onetimeDump = 'methods'; # method output gets used there
2258 =head4 C<f> - switch files
2262 $cmd =~ /^f\b\s*(.*)/ && do {
2266 # help for no arguments (old-style was return from sub).
2269 "The old f command is now the r command.\n"; # hint
2270 print $OUT "The new f command switches filenames.\n";
2272 } ## end if (!$file)
2274 # if not in magic file list, try a close match.
2275 if ( !defined $main::{ '_<' . $file } ) {
2276 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2278 $try = substr( $try, 2 );
2279 print $OUT "Choosing $try matching '$file':\n";
2282 } ## end if (($try) = grep(m#^_<.*$file#...
2283 } ## end if (!defined $main::{ ...
2285 # If not successfully switched now, we failed.
2286 if ( !defined $main::{ '_<' . $file } ) {
2287 print $OUT "No file matching '$file' is loaded.\n";
2291 # We switched, so switch the debugger internals around.
2292 elsif ( $file ne $filename ) {
2293 *dbline = $main::{ '_<' . $file };
2298 } ## end elsif ($file ne $filename)
2300 # We didn't switch; say we didn't.
2302 print $OUT "Already in $file.\n";
2307 =head4 C<.> - return to last-executed line.
2309 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2310 and then we look up the line in the magical C<%dbline> hash.
2315 $cmd =~ /^\.$/ && do {
2316 $incr = -1; # stay at current line
2318 # Reset everything to the old location.
2320 $filename = $filename_ini;
2321 *dbline = $main::{ '_<' . $filename };
2325 print_lineinfo($position);
2329 =head4 C<-> - back one window
2331 We change C<$start> to be one window back; if we go back past the first line,
2332 we set it to be the first line. We ser C<$incr> to put us back at the
2333 currently-executing line, and then put a C<l $start +> (list one window from
2334 C<$start>) in C<$cmd> to be executed later.
2338 # - - back a window.
2339 $cmd =~ /^-$/ && do {
2341 # back up by a window; go to 1 if back too far.
2342 $start -= $incr + $window + 1;
2343 $start = 1 if $start <= 0;
2344 $incr = $window - 1;
2346 # Generate and execute a "l +" command (handled below).
2347 $cmd = 'l ' . ($start) . '+';
2350 =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>, {, {{>
2352 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2353 problems, most notably that the default case of several commands destroying
2354 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2355 retain the old commands for those who were used to using them or who preferred
2356 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2357 deal with them instead of processing them in-line.
2361 # All of these commands were remapped in perl 5.8.0;
2362 # we send them off to the secondary dispatcher (see below).
2363 $cmd =~ /^([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do {
2364 &cmd_wrapper( $1, $2, $line );
2368 =head4 C<y> - List lexicals in higher scope
2370 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2371 above the current one and then displays then using C<dumpvar.pl>.
2375 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do {
2377 # See if we've got the necessary support.
2378 eval { require PadWalker; PadWalker->VERSION(0.08) }
2381 ? "PadWalker module not found - please install\n"
2386 # Load up dumpvar if we don't have it. If we can, that is.
2387 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
2388 defined &main::dumpvar
2389 or print $OUT "dumpvar.pl not available.\n"
2392 # Got all the modules we need. Find them and print them.
2393 my @vars = split( ' ', $2 || '' );
2396 my $h = eval { PadWalker::peek_my( ( $1 || 0 ) + 1 ) };
2398 # Oops. Can't find it.
2399 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2401 # Show the desired vars with dumplex().
2402 my $savout = select($OUT);
2404 # Have dumplex dump the lexicals.
2405 dumpvar::dumplex( $_, $h->{$_},
2406 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
2413 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2415 All of the commands below this point don't work after the program being
2416 debugged has ended. All of them check to see if the program has ended; this
2417 allows the commands to be relocated without worrying about a 'line of
2418 demarcation' above which commands can be entered anytime, and below which
2421 =head4 C<n> - single step, but don't trace down into subs
2423 Done by setting C<$single> to 2, which forces subs to execute straight through
2424 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2425 so a null command knows what to re-execute.
2430 $cmd =~ /^n$/ && do {
2431 end_report(), next CMD if $finished and $level <= 1;
2433 # Single step, but don't enter subs.
2436 # Save for empty command (repeat last).
2441 =head4 C<s> - single-step, entering subs
2443 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2444 subs. Also saves C<s> as C<$lastcmd>.
2449 $cmd =~ /^s$/ && do {
2451 # Get out and restart the command loop if program
2453 end_report(), next CMD if $finished and $level <= 1;
2455 # Single step should enter subs.
2458 # Save for empty command (repeat last).
2463 =head4 C<c> - run continuously, setting an optional breakpoint
2465 Most of the code for this command is taken up with locating the optional
2466 breakpoint, which is either a subroutine name or a line number. We set
2467 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2468 in this and all call levels above this one.
2472 # c - start continuous execution.
2473 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do {
2475 # Hey, show's over. The debugged program finished
2476 # executing already.
2477 end_report(), next CMD if $finished and $level <= 1;
2479 # Capture the place to put a one-time break.
2482 # Probably not needed, since we finish an interactive
2483 # sub-session anyway...
2484 # local $filename = $filename;
2485 # local *dbline = *dbline; # XXX Would this work?!
2487 # The above question wonders if localizing the alias
2488 # to the magic array works or not. Since it's commented
2489 # out, we'll just leave that to speculation for now.
2491 # If the "subname" isn't all digits, we'll assume it
2492 # is a subroutine name, and try to find it.
2493 if ( $subname =~ /\D/ ) { # subroutine name
2494 # Qualify it to the current package unless it's
2495 # already qualified.
2496 $subname = $package . "::" . $subname
2497 unless $subname =~ /::/;
2499 # find_sub will return "file:line_number" corresponding
2500 # to where the subroutine is defined; we call find_sub,
2501 # break up the return value, and assign it in one
2503 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2505 # Force the line number to be numeric.
2508 # If we got a line number, we found the sub.
2511 # Switch all the debugger's internals around so
2512 # we're actually working with that file.
2514 *dbline = $main::{ '_<' . $filename };
2516 # Mark that there's a breakpoint in this file.
2517 $had_breakpoints{$filename} |= 1;
2519 # Scan forward to the first executable line
2520 # after the 'sub whatever' line.
2522 ++$i while $dbline[$i] == 0 && $i < $max;
2525 # We didn't find a sub by that name.
2527 print $OUT "Subroutine $subname not found.\n";
2530 } ## end if ($subname =~ /\D/)
2532 # At this point, either the subname was all digits (an
2533 # absolute line-break request) or we've scanned through
2534 # the code following the definition of the sub, looking
2535 # for an executable, which we may or may not have found.
2537 # If $i (which we set $subname from) is non-zero, we
2538 # got a request to break at some line somewhere. On
2539 # one hand, if there wasn't any real subroutine name
2540 # involved, this will be a request to break in the current
2541 # file at the specified line, so we have to check to make
2542 # sure that the line specified really is breakable.
2544 # On the other hand, if there was a subname supplied, the
2545 # preceding block has moved us to the proper file and
2546 # location within that file, and then scanned forward
2547 # looking for the next executable line. We have to make
2548 # sure that one was found.
2550 # On the gripping hand, we can't do anything unless the
2551 # current value of $i points to a valid breakable line.
2556 if ( $dbline[$i] == 0 ) {
2557 print $OUT "Line $i not breakable.\n";
2561 # Yes. Set up the one-time-break sigil.
2562 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2563 _enable_breakpoint_temp_enabled_status($filename, $i);
2566 # Turn off stack tracing from here up.
2567 for ( $i = 0 ; $i <= $stack_depth ; ) {
2568 $stack[ $i++ ] &= ~1;
2573 =head4 C<r> - return from a subroutine
2575 For C<r> to work properly, the debugger has to stop execution again
2576 immediately after the return is executed. This is done by forcing
2577 single-stepping to be on in the call level above the current one. If
2578 we are printing return values when a C<r> is executed, set C<$doret>
2579 appropriately, and force us out of the command loop.
2583 # r - return from the current subroutine.
2584 $cmd =~ /^r$/ && do {
2586 # Can't do anything if the program's over.
2587 end_report(), next CMD if $finished and $level <= 1;
2589 # Turn on stack trace.
2590 $stack[$stack_depth] |= 1;
2592 # Print return value unless the stack is empty.
2593 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2597 =head4 C<T> - stack trace
2599 Just calls C<DB::print_trace>.
2603 $cmd =~ /^T$/ && do {
2604 print_trace( $OUT, 1 ); # skip DB
2608 =head4 C<w> - List window around current line.
2610 Just calls C<DB::cmd_w>.
2614 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w( 'w', $1 ); next CMD; };
2616 =head4 C<W> - watch-expression processing.
2618 Just calls C<DB::cmd_W>.
2622 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W( 'W', $1 ); next CMD; };
2624 =head4 C</> - search forward for a string in the source
2626 We take the argument and treat it as a pattern. If it turns out to be a
2627 bad one, we return the error we got from trying to C<eval> it and exit.
2628 If not, we create some code to do the search and C<eval> it so it can't
2633 $cmd =~ /^\/(.*)$/ && do {
2635 # The pattern as a string.
2638 # Remove the final slash.
2639 $inpat =~ s:([^\\])/$:$1:;
2641 # If the pattern isn't null ...
2642 if ( $inpat ne "" ) {
2644 # Turn of warn and die procesing for a bit.
2645 local $SIG{__DIE__};
2646 local $SIG{__WARN__};
2648 # Create the pattern.
2649 eval '$inpat =~ m' . "\a$inpat\a";
2652 # Oops. Bad pattern. No biscuit.
2653 # Print the eval error and go back for more
2659 } ## end if ($inpat ne "")
2661 # Set up to stop on wrap-around.
2664 # Don't move off the current line.
2667 # Done in eval so nothing breaks if the pattern
2668 # does something weird.
2671 # Move ahead one line.
2674 # Wrap if we pass the last line.
2675 $start = 1 if ($start > $max);
2677 # Stop if we have gotten back to this line again,
2678 last if ($start == $end);
2680 # A hit! (Note, though, that we are doing
2681 # case-insensitive matching. Maybe a qr//
2682 # expression would be better, so the user could
2683 # do case-sensitive matching if desired.
2684 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2685 if ($slave_editor) {
2686 # Handle proper escaping in the slave.
2687 print $OUT "\032\032$filename:$start:0\n";
2690 # Just print the line normally.
2691 print $OUT "$start:\t",$dbline[$start],"\n";
2693 # And quit since we found something.
2698 # If we wrapped, there never was a match.
2699 print $OUT "/$pat/: not found\n" if ( $start == $end );
2703 =head4 C<?> - search backward for a string in the source
2705 Same as for C</>, except the loop runs backwards.
2709 # ? - backward pattern search.
2710 $cmd =~ /^\?(.*)$/ && do {
2712 # Get the pattern, remove trailing question mark.
2714 $inpat =~ s:([^\\])\?$:$1:;
2716 # If we've got one ...
2717 if ( $inpat ne "" ) {
2719 # Turn off die & warn handlers.
2720 local $SIG{__DIE__};
2721 local $SIG{__WARN__};
2722 eval '$inpat =~ m' . "\a$inpat\a";
2726 # Ouch. Not good. Print the error.
2731 } ## end if ($inpat ne "")
2733 # Where we are now is where to stop after wraparound.
2736 # Don't move away from this line.
2739 # Search inside the eval to prevent pattern badness
2746 # Wrap if we pass the first line.
2748 $start = $max if ($start <= 0);
2750 # Quit if we get back where we started,
2751 last if ($start == $end);
2754 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2755 if ($slave_editor) {
2756 # Yep, follow slave editor requirements.
2757 print $OUT "\032\032$filename:$start:0\n";
2760 # Yep, just print normally.
2761 print $OUT "$start:\t",$dbline[$start],"\n";
2769 # Say we failed if the loop never found anything,
2770 print $OUT "?$pat?: not found\n" if ( $start == $end );
2774 =head4 C<$rc> - Recall command
2776 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2777 that the terminal supports history). It find the the command required, puts it
2778 into C<$cmd>, and redoes the loop to execute it.
2782 # $rc - recall command.
2783 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do {
2785 # No arguments, take one thing off history.
2786 pop(@hist) if length($cmd) > 1;
2788 # Relative (- found)?
2789 # Y - index back from most recent (by 1 if bare minus)
2790 # N - go to that particular command slot or the last
2791 # thing if nothing following.
2792 $i = $1 ? ( $#hist - ( $2 || 1 ) ) : ( $2 || $#hist );
2794 # Pick out the command desired.
2797 # Print the command to be executed and restart the loop
2798 # with that command in the buffer.
2799 print $OUT $cmd, "\n";
2803 =head4 C<$sh$sh> - C<system()> command
2805 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2806 C<STDOUT> from getting messed up.
2810 # $sh$sh - run a shell command (if it's all ASCII).
2811 # Can't run shell commands with Unicode in the debugger, hmm.
2812 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do {
2819 =head4 C<$rc I<pattern> $rc> - Search command history
2821 Another command to manipulate C<@hist>: this one searches it with a pattern.
2822 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
2826 # $rc pattern $rc - find a command in the history.
2827 $cmd =~ /^$rc([^$rc].*)$/ && do {
2829 # Create the pattern to use.
2832 # Toss off last entry if length is >1 (and it always is).
2833 pop(@hist) if length($cmd) > 1;
2835 # Look backward through the history.
2836 for ( $i = $#hist ; $i ; --$i ) {
2838 # Stop if we find it.
2839 last if $hist[$i] =~ /$pat/;
2845 print $OUT "No such command!\n\n";
2849 # Found it. Put it in the buffer, print it, and process it.
2851 print $OUT $cmd, "\n";
2855 =head4 C<$sh> - Invoke a shell
2857 Uses C<DB::system> to invoke a shell.
2861 # $sh - start a shell.
2862 $cmd =~ /^$sh$/ && do {
2864 # Run the user's shell. If none defined, run Bourne.
2865 # We resume execution when the shell terminates.
2866 &system( $ENV{SHELL} || "/bin/sh" );
2870 =head4 C<$sh I<command>> - Force execution of a command in a shell
2872 Like the above, but the command is passed to the shell. Again, we use
2873 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
2877 # $sh command - start a shell and run a command in it.
2878 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do {
2880 # XXX: using csh or tcsh destroys sigint retvals!
2881 #&system($1); # use this instead
2883 # use the user's shell, or Bourne if none defined.
2884 &system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
2888 =head4 C<H> - display commands in history
2890 Prints the contents of C<@hist> (if any).
2894 $cmd =~ /^H\b\s*\*/ && do {
2895 @hist = @truehist = ();
2896 print $OUT "History cleansed\n";
2900 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
2902 # Anything other than negative numbers is ignored by
2903 # the (incorrect) pattern, so this test does nothing.
2904 $end = $2 ? ( $#hist - $2 ) : 0;
2906 # Set to the minimum if less than zero.
2907 $hist = 0 if $hist < 0;
2909 # Start at the end of the array.
2910 # Stay in while we're still above the ending value.
2911 # Tick back by one each time around the loop.
2912 for ( $i = $#hist ; $i > $end ; $i-- ) {
2914 # Print the command unless it has no arguments.
2915 print $OUT "$i: ", $hist[$i], "\n"
2916 unless $hist[$i] =~ /^.?$/;
2921 =head4 C<man, doc, perldoc> - look up documentation
2923 Just calls C<runman()> to print the appropriate document.
2927 # man, perldoc, doc - show manual pages.
2928 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do {
2935 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
2936 the bottom of the loop.
2940 # p - print (no args): print $_.
2941 $cmd =~ s/^p$/print {\$DB::OUT} \$_/;
2943 # p - print the given expression.
2944 $cmd =~ s/^p\b/print {\$DB::OUT} /;
2946 =head4 C<=> - define command alias
2948 Manipulates C<%alias> to add or list command aliases.
2952 # = - set up a command alias.
2953 $cmd =~ s/^=\s*// && do {
2955 if ( length $cmd == 0 ) {
2957 # No args, get current aliases.
2958 @keys = sort keys %alias;
2960 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
2962 # Creating a new alias. $k is alias name, $v is
2965 # can't use $_ or kill //g state
2966 for my $x ( $k, $v ) {
2968 # Escape "alarm" characters.
2972 # Substitute key for value, using alarm chars
2973 # as separators (which is why we escaped them in
2975 $alias{$k} = "s\a$k\a$v\a";
2977 # Turn off standard warn and die behavior.
2978 local $SIG{__DIE__};
2979 local $SIG{__WARN__};
2982 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
2984 # Nope. Bad alias. Say so and get out.
2985 print $OUT "Can't alias $k to $v: $@\n";
2990 # We'll only list the new one.
2992 } ## end elsif (my ($k, $v) = ($cmd...
2994 # The argument is the alias to list.
3002 # Messy metaquoting: Trim the substitution code off.
3003 # We use control-G as the delimiter because it's not
3004 # likely to appear in the alias.
3005 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3008 print $OUT "$k\t= $1\n";
3010 elsif ( defined $alias{$k} ) {
3012 # Couldn't trim it off; just print the alias code.
3013 print $OUT "$k\t$alias{$k}\n";
3018 print "No alias for $k\n";
3020 } ## end for my $k (@keys)
3024 =head4 C<source> - read commands from a file.
3026 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3031 # source - read commands from a file (or pipe!) and execute.
3032 $cmd =~ /^source\s+(.*\S)/ && do {
3033 if ( open my $fh, $1 ) {
3035 # Opened OK; stick it in the list of file handles.
3041 &warn("Can't execute '$1': $!\n");
3046 $cmd =~ /^(enable|disable)\s+(\S+)\s*$/ && do {
3047 my ($cmd, $position) = ($1, $2);
3049 my ($fn, $line_num);
3050 if ($position =~ m{\A\d+\z})
3053 $line_num = $position;
3055 elsif ($position =~ m{\A(.*):(\d+)\z})
3057 ($fn, $line_num) = ($1, $2);
3061 &warn("Wrong spec for enable/disable argument.\n");
3065 if (_has_breakpoint_data_ref($fn, $line_num)) {
3066 _set_breakpoint_enabled_status($fn, $line_num,
3067 ($cmd eq 'enable' ? 1 : '')
3071 &warn("No breakpoint set at ${fn}:${line_num}\n");
3078 =head4 C<save> - send current history to a file
3080 Takes the complete history, (not the shrunken version you see with C<H>),
3081 and saves it to the given filename, so it can be replayed using C<source>.
3083 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3087 # save source - write commands to a file for later use
3088 $cmd =~ /^save\s*(.*)$/ && do {
3089 my $file = $1 || '.perl5dbrc'; # default?
3090 if ( open my $fh, "> $file" ) {
3092 # chomp to remove extraneous newlines from source'd files
3093 chomp( my @truelist =
3094 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3096 print $fh join( "\n", @truelist );
3097 print "commands saved in $file\n";
3100 &warn("Can't save debugger commands in '$1': $!\n");
3105 =head4 C<R> - restart
3107 Restart the debugger session.
3109 =head4 C<rerun> - rerun the current session
3111 Return to any given position in the B<true>-history list
3115 # R - restart execution.
3116 # rerun - controlled restart execution.
3117 $cmd =~ /^(R|rerun\s*(.*))$/ && do {
3118 my @args = ($1 eq 'R' ? restart() : rerun($2));
3120 # Close all non-system fds for a clean restart. A more
3121 # correct method would be to close all fds that were not
3122 # open when the process started, but this seems to be
3123 # hard. See "debugger 'R'estart and open database
3124 # connections" on p5p.
3126 my $max_fd = 1024; # default if POSIX can't be loaded
3127 if (eval { require POSIX }) {
3128 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
3131 if (defined $max_fd) {
3132 foreach ($^F+1 .. $max_fd-1) {
3133 next unless open FD_TO_CLOSE, "<&=$_";
3138 # And run Perl again. We use exec() to keep the
3139 # PID stable (and that way $ini_pids is still valid).
3140 exec(@args) || print $OUT "exec failed: $!\n";
3145 =head4 C<|, ||> - pipe output through the pager.
3147 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3148 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3149 pipe to the pager (restoring the output filehandles if this fails). If this
3150 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3151 set C<$signal>, sending us back into the debugger.
3153 We then trim off the pipe symbols and C<redo> the command loop at the
3154 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3159 # || - run command in the pager, with output to DB::OUT.
3160 $cmd =~ /^\|\|?\s*[^|]/ && do {
3161 if ( $pager =~ /^\|/ ) {
3163 # Default pager is into a pipe. Redirect I/O.
3164 open( SAVEOUT, ">&STDOUT" )
3165 || &warn("Can't save STDOUT");
3166 open( STDOUT, ">&OUT" )
3167 || &warn("Can't redirect STDOUT");
3168 } ## end if ($pager =~ /^\|/)
3171 # Not into a pipe. STDOUT is safe.
3172 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3175 # Fix up environment to record we have less if so.
3178 unless ( $piped = open( OUT, $pager ) ) {
3180 # Couldn't open pipe to pager.
3181 &warn("Can't pipe output to '$pager'");
3182 if ( $pager =~ /^\|/ ) {
3184 # Redirect I/O back again.
3185 open( OUT, ">&STDOUT" ) # XXX: lost message
3186 || &warn("Can't restore DB::OUT");
3187 open( STDOUT, ">&SAVEOUT" )
3188 || &warn("Can't restore STDOUT");
3190 } ## end if ($pager =~ /^\|/)
3193 # Redirect I/O. STDOUT already safe.
3194 open( OUT, ">&STDOUT" ) # XXX: lost message
3195 || &warn("Can't restore DB::OUT");
3198 } ## end unless ($piped = open(OUT,...
3200 # Set up broken-pipe handler if necessary.
3201 $SIG{PIPE} = \&DB::catch
3203 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
3205 # Save current filehandle, unbuffer out, and put it back.
3206 $selected = select(OUT);
3209 # Don't put it back if pager was a pipe.
3210 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
3212 # Trim off the pipe symbols and run the command now.
3213 $cmd =~ s/^\|+\s*//;
3217 =head3 END OF COMMAND PARSING
3219 Anything left in C<$cmd> at this point is a Perl expression that we want to
3220 evaluate. We'll always evaluate in the user's context, and fully qualify
3221 any variables we might want to address in the C<DB> package.
3225 # t - turn trace on.
3226 $cmd =~ s/^t\s+(\d+)?/\$DB::trace |= 1;\n/ && do {
3227 $trace_to_depth = $1 ? $stack_depth||0 + $1 : 1E9;
3230 # s - single-step. Remember the last command was 's'.
3231 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' };
3233 # n - single-step, but not into subs. Remember last command
3235 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' };
3239 # Make sure the flag that says "the debugger's running" is
3240 # still on, to make sure we get control again.
3241 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3243 # Run *our* eval that executes in the caller's context.
3246 # Turn off the one-time-dump stuff now.
3248 $onetimeDump = undef;
3249 $onetimedumpDepth = undef;
3251 elsif ( $term_pid == $$ ) {
3252 eval { # May run under miniperl, when not available...
3257 # XXX If this is the master pid, print a newline.
3260 } ## end while (($term || &setterm...
3262 =head3 POST-COMMAND PROCESSING
3264 After each command, we check to see if the command output was piped anywhere.
3265 If so, we go through the necessary code to unhook the pipe and go back to
3266 our standard filehandles for input and output.
3272 # At the end of every command:
3275 # Unhook the pipe mechanism now.
3276 if ( $pager =~ /^\|/ ) {
3278 # No error from the child.
3281 # we cannot warn here: the handle is missing --tchrist
3282 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
3284 # most of the $? crud was coping with broken cshisms
3285 # $? is explicitly set to 0, so this never runs.
3287 print SAVEOUT "Pager '$pager' failed: ";
3289 print SAVEOUT "shell returned -1\n";
3292 print SAVEOUT ( $? & 127 )
3293 ? " (SIG#" . ( $? & 127 ) . ")"
3294 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3297 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3301 # Reopen filehandle for our output (if we can) and
3302 # restore STDOUT (if we can).
3303 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3304 open( STDOUT, ">&SAVEOUT" )
3305 || &warn("Can't restore STDOUT");
3307 # Turn off pipe exception handler if necessary.
3308 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
3310 # Will stop ignoring SIGPIPE if done like nohup(1)
3311 # does SIGINT but Perl doesn't give us a choice.
3312 } ## end if ($pager =~ /^\|/)
3315 # Non-piped "pager". Just restore STDOUT.
3316 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3319 # Close filehandle pager was using, restore the normal one
3322 select($selected), $selected = "" unless $selected eq "";
3326 } ## end if ($piped)
3329 =head3 COMMAND LOOP TERMINATION
3331 When commands have finished executing, we come here. If the user closed the
3332 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3333 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3334 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3335 The interpreter will then execute the next line and then return control to us
3340 # No more commands? Quit.
3341 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
3343 # Evaluate post-prompt commands.
3344 foreach $evalarg (@$post) {
3347 } # if ($single || $signal)
3349 # Put the user's globals back where you found them.
3350 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3354 # The following code may be executed now:
3359 C<sub> is called whenever a subroutine call happens in the program being
3360 debugged. The variable C<$DB::sub> contains the name of the subroutine
3363 The core function of this subroutine is to actually call the sub in the proper
3364 context, capturing its output. This of course causes C<DB::DB> to get called
3365 again, repeating until the subroutine ends and returns control to C<DB::sub>
3366 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3367 return value, and returns its captured copy of the return value as its own
3368 return value. The value then feeds back into the program being debugged as if
3369 C<DB::sub> hadn't been there at all.
3371 C<sub> does all the work of printing the subroutine entry and exit messages
3372 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3373 and also prints the return value if needed (for the C<r> command and if
3374 the 16 bit is set in C<$frame>).
3376 It also tracks the subroutine call depth by saving the current setting of
3377 C<$single> in the C<@stack> package global; if this exceeds the value in
3378 C<$deep>, C<sub> automatically turns on printing of the current depth by
3379 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
3380 of stop/don't stop on entry to subs set as it currently is set.
3382 =head3 C<caller()> support
3384 If C<caller()> is called from the package C<DB>, it provides some
3385 additional data, in the following order:
3391 The package name the sub was in
3393 =item * C<$filename>
3395 The filename it was defined in
3399 The line number it was defined on
3401 =item * C<$subroutine>
3403 The subroutine name; C<(eval)> if an C<eval>().
3407 1 if it has arguments, 0 if not
3409 =item * C<$wantarray>
3411 1 if array context, 0 if scalar context
3413 =item * C<$evaltext>
3415 The C<eval>() text, if any (undefined for C<eval BLOCK>)
3417 =item * C<$is_require>
3419 frame was created by a C<use> or C<require> statement
3423 pragma information; subject to change between versions
3427 pragma information; subject to change between versions
3429 =item * C<@DB::args>
3431 arguments with which the subroutine was invoked
3438 # Do not use a regex in this subroutine -> results in corrupted memory
3439 # See: [perl #66110]
3441 # lock ourselves under threads
3444 # Whether or not the autoloader was running, a scalar to put the
3445 # sub's return value in (if needed), and an array to put the sub's
3446 # return value in (if needed).
3447 my ( $al, $ret, @ret ) = "";
3448 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
3449 print "creating new thread\n";
3452 # If the last ten characters are '::AUTOLOAD', note we've traced
3453 # into AUTOLOAD for $sub.
3454 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3455 $al = " for $$sub" if defined $$sub;
3458 # We stack the stack pointer and then increment it to protect us
3459 # from a situation that might unwind a whole bunch of call frames
3460 # at once. Localizing the stack pointer means that it will automatically
3461 # unwind the same amount when multiple stack frames are unwound.
3462 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3465 $#stack = $stack_depth;
3467 # Save current single-step setting.
3468 $stack[-1] = $single;
3470 # Turn off all flags except single-stepping.
3473 # If we've gotten really deeply recursed, turn on the flag that will
3474 # make us stop with the 'deep recursion' message.
3475 $single |= 4 if $stack_depth == $deep;
3477 # If frame messages are on ...
3479 $frame & 4 # Extended frame entry message
3481 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3483 # Why -1? But it works! :-(
3484 # Because print_trace will call add 1 to it and then call
3485 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3487 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3489 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3491 # standard frame entry message
3495 # Determine the sub's return type, and capture appropriately.
3498 # Called in array context. call sub and capture output.
3499 # DB::DB will recursively get control again if appropriate; we'll come
3500 # back here when the sub is finished.
3503 # Pop the single-step value back off the stack.
3504 $single |= $stack[ $stack_depth-- ];
3506 # Check for exit trace messages...
3508 $frame & 4 # Extended exit message
3510 print_lineinfo( ' ' x $stack_depth, "out " ),
3511 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3513 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3515 # Standard exit message
3519 # Print the return info if we need to.
3520 if ( $doret eq $stack_depth or $frame & 16 ) {
3522 # Turn off output record separator.
3524 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3526 # Indent if we're printing because of $frame tracing.
3527 print $fh ' ' x $stack_depth if $frame & 16;
3529 # Print the return value.
3530 print $fh "list context return from $sub:\n";
3531 dumpit( $fh, \@ret );
3533 # And don't print it again.
3535 } ## end if ($doret eq $stack_depth...
3536 # And we have to return the return value now.
3538 } ## end if (wantarray)
3542 if ( defined wantarray ) {
3544 # Save the value if it's wanted at all.
3549 # Void return, explicitly.
3554 # Pop the single-step value off the stack.
3555 $single |= $stack[ $stack_depth-- ];
3557 # If we're doing exit messages...
3559 $frame & 4 # Extended messages
3561 print_lineinfo( ' ' x $stack_depth, "out " ),
3562 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3564 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3570 # If we are supposed to show the return value... same as before.
3571 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
3573 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3574 print $fh ( ' ' x $stack_depth ) if $frame & 16;
3577 ? "scalar context return from $sub: "
3578 : "void context return from $sub\n"
3580 dumpit( $fh, $ret ) if defined wantarray;
3582 } ## end if ($doret eq $stack_depth...
3584 # Return the appropriate scalar value.
3586 } ## end else [ if (wantarray)
3591 # lock ourselves under threads
3594 # Whether or not the autoloader was running, a scalar to put the
3595 # sub's return value in (if needed), and an array to put the sub's
3596 # return value in (if needed).
3597 my ( $al, $ret, @ret ) = "";
3598 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3599 print "creating new thread\n";
3602 # If the last ten characters are C'::AUTOLOAD', note we've traced
3603 # into AUTOLOAD for $sub.
3604 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3608 # We stack the stack pointer and then increment it to protect us
3609 # from a situation that might unwind a whole bunch of call frames
3610 # at once. Localizing the stack pointer means that it will automatically
3611 # unwind the same amount when multiple stack frames are unwound.
3612 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3615 $#stack = $stack_depth;
3617 # Save current single-step setting.
3618 $stack[-1] = $single;
3620 # Turn off all flags except single-stepping.
3623 # If we've gotten really deeply recursed, turn on the flag that will
3624 # make us stop with the 'deep recursion' message.
3625 $single |= 4 if $stack_depth == $deep;
3627 # If frame messages are on ...
3629 $frame & 4 # Extended frame entry message
3631 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3633 # Why -1? But it works! :-(
3634 # Because print_trace will call add 1 to it and then call
3635 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3637 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3639 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3641 # standard frame entry message
3645 # Pop the single-step value back off the stack.
3646 $single |= $stack[ $stack_depth-- ];
3648 # call the original lvalue sub.
3652 # Abstracting common code from multiple places elsewhere:
3653 sub depth_print_lineinfo {
3654 my $always_print = shift;
3656 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth);
3659 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
3661 In Perl 5.8.0, there was a major realignment of the commands and what they did,
3662 Most of the changes were to systematize the command structure and to eliminate
3663 commands that threw away user input without checking.
3665 The following sections describe the code added to make it easy to support
3666 multiple command sets with conflicting command names. This section is a start
3667 at unifying all command processing to make it simpler to develop commands.
3669 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
3670 number, and C<$dbline> (the current line) as arguments.
3672 Support functions in this section which have multiple modes of failure C<die>
3673 on error; the rest simply return a false value.
3675 The user-interface functions (all of the C<cmd_*> functions) just output
3680 The C<%set> hash defines the mapping from command letter to subroutine
3683 C<%set> is a two-level hash, indexed by set name and then by command name.
3684 Note that trying to set the CommandSet to C<foobar> simply results in the
3685 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
3694 'A' => 'pre580_null',
3696 'B' => 'pre580_null',
3697 'd' => 'pre580_null',
3700 'M' => 'pre580_null',
3702 'o' => 'pre580_null',
3708 '<' => 'pre590_prepost',
3709 '<<' => 'pre590_prepost',
3710 '>' => 'pre590_prepost',
3711 '>>' => 'pre590_prepost',
3712 '{' => 'pre590_prepost',
3713 '{{' => 'pre590_prepost',
3717 my %breakpoints_data;
3719 sub _has_breakpoint_data_ref {
3720 my ($filename, $line) = @_;
3723 exists( $breakpoints_data{$filename} )
3725 exists( $breakpoints_data{$filename}{$line} )
3729 sub _get_breakpoint_data_ref {
3730 my ($filename, $line) = @_;
3732 return ($breakpoints_data{$filename}{$line} ||= +{});
3735 sub _delete_breakpoint_data_ref {
3736 my ($filename, $line) = @_;
3738 delete($breakpoints_data{$filename}{$line});
3739 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) {
3740 delete($breakpoints_data{$filename});
3746 sub _set_breakpoint_enabled_status {
3747 my ($filename, $line, $status) = @_;
3749 _get_breakpoint_data_ref($filename, $line)->{'enabled'} =
3756 sub _enable_breakpoint_temp_enabled_status {
3757 my ($filename, $line) = @_;
3759 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1;
3764 sub _cancel_breakpoint_temp_enabled_status {
3765 my ($filename, $line) = @_;
3767 my $ref = _get_breakpoint_data_ref($filename, $line);
3769 delete ($ref->{'temp_enabled'});
3772 _delete_breakpoint_data_ref($filename, $line);
3778 sub _is_breakpoint_enabled {
3779 my ($filename, $line) = @_;
3781 my $data_ref = _get_breakpoint_data_ref($filename, $line);
3782 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'});
3785 =head2 C<cmd_wrapper()> (API)
3787 C<cmd_wrapper()> allows the debugger to switch command sets
3788 depending on the value of the C<CommandSet> option.
3790 It tries to look up the command in the C<%set> package-level I<lexical>
3791 (which means external entities can't fiddle with it) and create the name of
3792 the sub to call based on the value found in the hash (if it's there). I<All>
3793 of the commands to be handled in a set have to be added to C<%set>; if they
3794 aren't found, the 5.8.0 equivalent is called (if there is one).
3796 This code uses symbolic references.
3803 my $dblineno = shift;
3805 # Assemble the command subroutine's name by looking up the
3806 # command set and command name in %set. If we can't find it,
3807 # default to the older version of the command.
3809 . ( $set{$CommandSet}{$cmd}
3810 || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) );
3812 # Call the command subroutine, call it by name.
3813 return &$call( $cmd, $line, $dblineno );
3814 } ## end sub cmd_wrapper
3816 =head3 C<cmd_a> (command)
3818 The C<a> command handles pre-execution actions. These are associated with a
3819 particular line, so they're stored in C<%dbline>. We default to the current
3820 line if none is specified.
3826 my $line = shift || ''; # [.|line] expr
3829 # If it's dot (here), or not all digits, use the current line.
3830 $line =~ s/^(\.|(?:[^\d]))/$dbline/;
3832 # Should be a line number followed by an expression.
3833 if ( $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
3834 my ( $lineno, $expr ) = ( $1, $2 );
3836 # If we have an expression ...
3837 if ( length $expr ) {
3839 # ... but the line isn't breakable, complain.
3840 if ( $dbline[$lineno] == 0 ) {
3842 "Line $lineno($dbline[$lineno]) does not have an action?\n";
3846 # It's executable. Record that the line has an action.
3847 $had_breakpoints{$filename} |= 2;
3849 # Remove any action, temp breakpoint, etc.
3850 $dbline{$lineno} =~ s/\0[^\0]*//;
3852 # Add the action to the line.
3853 $dbline{$lineno} .= "\0" . action($expr);
3855 } ## end if (length $expr)
3856 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
3861 "Adding an action requires an optional lineno and an expression\n"
3866 =head3 C<cmd_A> (command)
3868 Delete actions. Similar to above, except the delete code is in a separate
3869 subroutine, C<delete_action>.
3875 my $line = shift || '';
3879 $line =~ s/^\./$dbline/;
3881 # Call delete_action with a null param to delete them all.
3882 # The '1' forces the eval to be true. It'll be false only
3883 # if delete_action blows up for some reason, in which case
3884 # we print $@ and get out.
3885 if ( $line eq '*' ) {
3886 eval { &delete_action(); 1 } or print $OUT $@ and return;
3889 # There's a real line number. Pass it to delete_action.
3890 # Error trapping is as above.
3891 elsif ( $line =~ /^(\S.*)/ ) {
3892 eval { &delete_action($1); 1 } or print $OUT $@ and return;
3895 # Swing and a miss. Bad syntax.
3898 "Deleting an action requires a line number, or '*' for all\n" ; # hint
3902 =head3 C<delete_action> (API)
3904 C<delete_action> accepts either a line number or C<undef>. If a line number
3905 is specified, we check for the line being executable (if it's not, it
3906 couldn't have had an action). If it is, we just take the action off (this
3907 will get any kind of an action, including breakpoints).
3913 if ( defined($i) ) {
3916 die "Line $i has no action .\n" if $dbline[$i] == 0;
3918 # Nuke whatever's there.
3919 $dbline{$i} =~ s/\0[^\0]*//; # \^a
3920 delete $dbline{$i} if $dbline{$i} eq '';
3923 print $OUT "Deleting all actions...\n";
3924 for my $file ( keys %had_breakpoints ) {
3925 local *dbline = $main::{ '_<' . $file };
3928 for ( $i = 1 ; $i <= $max ; $i++ ) {
3929 if ( defined $dbline{$i} ) {
3930 $dbline{$i} =~ s/\0[^\0]*//;
3931 delete $dbline{$i} if $dbline{$i} eq '';
3933 unless ( $had_breakpoints{$file} &= ~2 ) {
3934 delete $had_breakpoints{$file};
3936 } ## end for ($i = 1 ; $i <= $max...
3937 } ## end for my $file (keys %had_breakpoints)
3938 } ## end else [ if (defined($i))
3939 } ## end sub delete_action
3941 =head3 C<cmd_b> (command)
3943 Set breakpoints. Since breakpoints can be set in so many places, in so many
3944 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
3945 we try to parse the command type, and then shuttle it off to an appropriate
3946 subroutine to actually do the work of setting the breakpoint in the right
3953 my $line = shift; # [.|line] [cond]
3956 # Make . the current line number if it's there..
3957 $line =~ s/^\.(\s|\z)/$dbline$1/;
3959 # No line number, no condition. Simple break on current line.
3960 if ( $line =~ /^\s*$/ ) {
3961 &cmd_b_line( $dbline, 1 );
3964 # Break on load for a file.
3965 elsif ( $line =~ /^load\b\s*(.*)/ ) {
3971 # b compile|postpone <some sub> [<condition>]
3972 # The interpreter actually traps this one for us; we just put the
3973 # necessary condition in the %postponed hash.
3974 elsif ( $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
3976 # Capture the condition if there is one. Make it true if none.
3977 my $cond = length $3 ? $3 : '1';
3979 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
3980 # if it was 'compile'.
3981 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
3983 # De-Perl4-ify the name - ' separators to ::.
3984 $subname =~ s/\'/::/g;
3986 # Qualify it into the current package unless it's already qualified.
3987 $subname = "${'package'}::" . $subname unless $subname =~ /::/;
3989 # Add main if it starts with ::.
3990 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
3992 # Save the break type for this sub.
3993 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
3994 } ## end elsif ($line =~ ...
3995 # b <filename>:<line> [<condition>]
3996 elsif ($line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) {
3997 my ($filename, $line_num, $cond) = ($1, $2, $3);
3998 cmd_b_filename_line(
4001 (length($cond) ? $cond : '1'),
4004 # b <sub name> [<condition>]
4005 elsif ( $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4009 $cond = length $2 ? $2 : '1';
4010 &cmd_b_sub( $subname, $cond );
4013 # b <line> [<condition>].
4014 elsif ( $line =~ /^(\d*)\s*(.*)/ ) {
4016 # Capture the line. If none, it's the current line.
4017 $line = $1 || $dbline;
4019 # If there's no condition, make it '1'.
4020 $cond = length $2 ? $2 : '1';
4023 &cmd_b_line( $line, $cond );
4026 # Line didn't make sense.
4028 print "confused by line($line)?\n";
4032 =head3 C<break_on_load> (API)
4034 We want to break when this file is loaded. Mark this file in the
4035 C<%break_on_load> hash, and note that it has a breakpoint in
4036 C<%had_breakpoints>.
4042 $break_on_load{$file} = 1;
4043 $had_breakpoints{$file} |= 1;
4046 =head3 C<report_break_on_load> (API)
4048 Gives us an array of filenames that are set to break on load. Note that
4049 only files with break-on-load are in here, so simply showing the keys
4054 sub report_break_on_load {
4055 sort keys %break_on_load;
4058 =head3 C<cmd_b_load> (command)
4060 We take the file passed in and try to find it in C<%INC> (which maps modules
4061 to files they came from). We mark those files for break-on-load via
4062 C<break_on_load> and then report that it was done.
4070 # This is a block because that way we can use a redo inside it
4071 # even without there being any looping structure at all outside it.
4074 # Save short name and full path if found.
4076 push @files, $::INC{$file} if $::INC{$file};
4078 # Tack on .pm and do it again unless there was a '.' in the name
4080 $file .= '.pm', redo unless $file =~ /\./;
4083 # Do the real work here.
4084 break_on_load($_) for @files;
4086 # All the files that have break-on-load breakpoints.
4087 @files = report_break_on_load;
4089 # Normalize for the purposes of our printing this.
4092 print $OUT "Will stop on load of '@files'.\n";
4093 } ## end sub cmd_b_load
4095 =head3 C<$filename_error> (API package global)
4097 Several of the functions we need to implement in the API need to work both
4098 on the current file and on other files. We don't want to duplicate code, so
4099 C<$filename_error> is used to contain the name of the file that's being
4100 worked on (if it's not the current one).
4102 We can now build functions in pairs: the basic function works on the current
4103 file, and uses C<$filename_error> as part of its error message. Since this is
4104 initialized to C<"">, no filename will appear when we are working on the
4107 The second function is a wrapper which does the following:
4113 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4117 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4121 Calls the first function.
4123 The first function works on the I<current> file (i.e., the one we changed to),
4124 and prints C<$filename_error> in the error message (the name of the other file)
4125 if it needs to. When the functions return, C<*dbline> is restored to point
4126 to the actual current file (the one we're executing in) and
4127 C<$filename_error> is restored to C<"">. This restores everything to
4128 the way it was before the second function was called at all.
4130 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4137 $filename_error = '';
4139 =head3 breakable_line(from, to) (API)
4141 The subroutine decides whether or not a line in the current file is breakable.
4142 It walks through C<@dbline> within the range of lines specified, looking for
4143 the first line that is breakable.
4145 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4146 first line I<after> C<$to> that's breakable, if there is one.
4148 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4149 first line I<before> C<$to> that's breakable, if there is one.
4153 sub breakable_line {
4155 my ( $from, $to ) = @_;
4157 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4160 # If there are at least 2 arguments, we're trying to search a range.
4163 # $delta is positive for a forward search, negative for a backward one.
4164 my $delta = $from < $to ? +1 : -1;
4166 # Keep us from running off the ends of the file.
4167 my $limit = $delta > 0 ? $#dbline : 1;
4169 # Clever test. If you're a mathematician, it's obvious why this
4170 # test works. If not:
4171 # If $delta is positive (going forward), $limit will be $#dbline.
4172 # If $to is less than $limit, ($limit - $to) will be positive, times
4173 # $delta of 1 (positive), so the result is > 0 and we should use $to
4174 # as the stopping point.
4176 # If $to is greater than $limit, ($limit - $to) is negative,
4177 # times $delta of 1 (positive), so the result is < 0 and we should
4178 # use $limit ($#dbline) as the stopping point.
4180 # If $delta is negative (going backward), $limit will be 1.
4181 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4182 # (negative) so the result is > 0, and we use $to as the stopping
4185 # If $to is less than zero, ($limit - $to) will be positive,
4186 # times $delta of -1 (negative), so the result is not > 0, and
4187 # we use $limit (1) as the stopping point.
4189 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4190 # (negative), still giving zero; the result is not > 0, and
4191 # we use $limit (1) as the stopping point.
4193 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4194 # (negative), giving a positive (>0) value, so we'll set $limit to
4197 $limit = $to if ( $limit - $to ) * $delta > 0;
4199 # The real search loop.
4200 # $i starts at $from (the point we want to start searching from).
4201 # We move through @dbline in the appropriate direction (determined
4202 # by $delta: either -1 (back) or +1 (ahead).
4203 # We stay in as long as we haven't hit an executable line
4204 # ($dbline[$i] == 0 means not executable) and we haven't reached
4205 # the limit yet (test similar to the above).
4206 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4208 } ## end if (@_ >= 2)
4210 # If $i points to a line that is executable, return that.
4211 return $i unless $dbline[$i] == 0;
4213 # Format the message and print it: no breakable lines in range.
4214 my ( $pl, $upto ) = ( '', '' );
4215 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4217 # If there's a filename in filename_error, we'll see it.
4219 die "Line$pl $from$upto$filename_error not breakable\n";
4220 } ## end sub breakable_line
4222 =head3 breakable_line_in_filename(file, from, to) (API)
4224 Like C<breakable_line>, but look in another file.
4228 sub breakable_line_in_filename {
4230 # Capture the file name.
4233 # Swap the magic line array over there temporarily.
4234 local *dbline = $main::{ '_<' . $f };
4236 # If there's an error, it's in this other file.
4237 local $filename_error = " of '$f'";
4239 # Find the breakable line.
4242 # *dbline and $filename_error get restored when this block ends.
4244 } ## end sub breakable_line_in_filename
4246 =head3 break_on_line(lineno, [condition]) (API)
4248 Adds a breakpoint with the specified condition (or 1 if no condition was
4249 specified) to the specified line. Dies if it can't.
4254 my ( $i, $cond ) = @_;
4256 # Always true if no condition supplied.
4257 $cond = 1 unless @_ >= 2;
4263 # Woops, not a breakable line. $filename_error allows us to say
4264 # if it was in a different file.
4265 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4267 # Mark this file as having breakpoints in it.
4268 $had_breakpoints{$filename} |= 1;
4270 # If there is an action or condition here already ...
4271 if ( $dbline{$i} ) {
4273 # ... swap this condition for the existing one.
4274 $dbline{$i} =~ s/^[^\0]*/$cond/;
4278 # Nothing here - just add the condition.
4279 $dbline{$i} = $cond;
4281 _set_breakpoint_enabled_status($filename, $i, 1);
4283 } ## end sub break_on_line
4285 =head3 cmd_b_line(line, [condition]) (command)
4287 Wrapper for C<break_on_line>. Prints the failure message if it
4293 eval { break_on_line(@_); 1 } or do {
4295 print $OUT $@ and return;
4297 } ## end sub cmd_b_line
4299 =head3 cmd_b_filename_line(line, [condition]) (command)
4301 Wrapper for C<break_on_filename_line>. Prints the failure message if it
4306 sub cmd_b_filename_line {
4307 eval { break_on_filename_line(@_); 1 } or do {
4309 print $OUT $@ and return;
4313 =head3 break_on_filename_line(file, line, [condition]) (API)
4315 Switches to the file specified and then calls C<break_on_line> to set
4320 sub break_on_filename_line {
4321 my ( $f, $i, $cond ) = @_;
4323 # Always true if condition left off.
4324 $cond = 1 unless @_ >= 3;
4326 # Switch the magical hash temporarily.
4327 local *dbline = $main::{ '_<' . $f };
4329 # Localize the variables that break_on_line uses to make its message.
4330 local $filename_error = " of '$f'";
4331 local $filename = $f;
4333 # Add the breakpoint.
4334 break_on_line( $i, $cond );
4335 } ## end sub break_on_filename_line
4337 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4339 Switch to another file, search the range of lines specified for an
4340 executable one, and put a breakpoint on the first one you find.
4344 sub break_on_filename_line_range {
4345 my ( $f, $from, $to, $cond ) = @_;
4347 # Find a breakable line if there is one.
4348 my $i = breakable_line_in_filename( $f, $from, $to );
4350 # Always true if missing.
4351 $cond = 1 unless @_ >= 3;
4353 # Add the breakpoint.
4354 break_on_filename_line( $f, $i, $cond );
4355 } ## end sub break_on_filename_line_range
4357 =head3 subroutine_filename_lines(subname, [condition]) (API)
4359 Search for a subroutine within a given file. The condition is ignored.
4360 Uses C<find_sub> to locate the desired subroutine.
4364 sub subroutine_filename_lines {
4365 my ( $subname, $cond ) = @_;
4367 # Returned value from find_sub() is fullpathname:startline-endline.
4368 # The match creates the list (fullpathname, start, end). Falling off
4369 # the end of the subroutine returns this implicitly.
4370 find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/;
4371 } ## end sub subroutine_filename_lines
4373 =head3 break_subroutine(subname) (API)
4375 Places a break on the first line possible in the specified subroutine. Uses
4376 C<subroutine_filename_lines> to find the subroutine, and
4377 C<break_on_filename_line_range> to place the break.
4381 sub break_subroutine {
4382 my $subname = shift;
4384 # Get filename, start, and end.
4385 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
4386 or die "Subroutine $subname not found.\n";
4388 # Null condition changes to '1' (always true).
4389 $cond = 1 unless @_ >= 2;
4391 # Put a break the first place possible in the range of lines
4392 # that make up this subroutine.
4393 break_on_filename_line_range( $file, $s, $e, @_ );
4394 } ## end sub break_subroutine
4396 =head3 cmd_b_sub(subname, [condition]) (command)
4398 We take the incoming subroutine name and fully-qualify it as best we can.
4402 =item 1. If it's already fully-qualified, leave it alone.
4404 =item 2. Try putting it in the current package.
4406 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
4408 =item 4. If it starts with '::', put it in 'main::'.
4412 After all this cleanup, we call C<break_subroutine> to try to set the
4418 my ( $subname, $cond ) = @_;
4420 # Add always-true condition if we have none.
4421 $cond = 1 unless @_ >= 2;
4423 # If the subname isn't a code reference, qualify it so that
4424 # break_subroutine() will work right.
4425 unless ( ref $subname eq 'CODE' ) {
4428 $subname =~ s/\'/::/g;
4431 # Put it in this package unless it's already qualified.
4432 $subname = "${'package'}::" . $subname
4433 unless $subname =~ /::/;
4435 # Requalify it into CORE::GLOBAL if qualifying it into this
4436 # package resulted in its not being defined, but only do so
4437 # if it really is in CORE::GLOBAL.
4438 $subname = "CORE::GLOBAL::$s"
4439 if not defined &$subname
4441 and defined &{"CORE::GLOBAL::$s"};
4443 # Put it in package 'main' if it has a leading ::.
4444 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4446 } ## end unless (ref $subname eq 'CODE')
4448 # Try to set the breakpoint.
4449 eval { break_subroutine( $subname, $cond ); 1 } or do {
4451 print $OUT $@ and return;
4453 } ## end sub cmd_b_sub
4455 =head3 C<cmd_B> - delete breakpoint(s) (command)
4457 The command mostly parses the command line and tries to turn the argument
4458 into a line spec. If it can't, it uses the current line. It then calls
4459 C<delete_breakpoint> to actually do the work.
4461 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
4462 thereby deleting all the breakpoints.
4469 # No line spec? Use dbline.
4470 # If there is one, use it if it's non-zero, or wipe it out if it is.
4471 my $line = ( $_[0] =~ /^\./ ) ? $dbline : shift || '';
4474 # If the line was dot, make the line the current one.
4475 $line =~ s/^\./$dbline/;
4477 # If it's * we're deleting all the breakpoints.
4478 if ( $line eq '*' ) {
4479 eval { &delete_breakpoint(); 1 } or print $OUT $@ and return;
4482 # If there is a line spec, delete the breakpoint on that line.
4483 elsif ( $line =~ /^(\S.*)/ ) {
4484 eval { &delete_breakpoint( $line || $dbline ); 1 } or do {
4486 print $OUT $@ and return;
4488 } ## end elsif ($line =~ /^(\S.*)/)
4493 "Deleting a breakpoint requires a line number, or '*' for all\n"
4498 =head3 delete_breakpoint([line]) (API)
4500 This actually does the work of deleting either a single breakpoint, or all
4503 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
4504 just drop out with a message saying so. If it is, we remove the condition
4505 part of the 'condition\0action' that says there's a breakpoint here. If,
4506 after we've done that, there's nothing left, we delete the corresponding
4507 line in C<%dbline> to signal that no action needs to be taken for this line.
4509 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
4510 which lists all currently-loaded files which have breakpoints. We then look
4511 at each line in each of these files, temporarily switching the C<%dbline>
4512 and C<@dbline> structures to point to the files in question, and do what
4513 we did in the single line case: delete the condition in C<@dbline>, and
4514 delete the key in C<%dbline> if nothing's left.
4516 We then wholesale delete C<%postponed>, C<%postponed_file>, and
4517 C<%break_on_load>, because these structures contain breakpoints for files
4518 and code that haven't been loaded yet. We can just kill these off because there
4519 are no magical debugger structures associated with them.
4523 sub delete_breakpoint {
4528 # If we got a line, delete just that one.
4529 if ( defined($i) ) {
4531 # Woops. This line wasn't breakable at all.
4532 die "Line $i not breakable.\n" if $dbline[$i] == 0;
4534 # Kill the condition, but leave any action.
4535 $dbline{$i} =~ s/^[^\0]*//;
4537 # Remove the entry entirely if there's no action left.
4538 if ($dbline{$i} eq '') {
4540 _delete_breakpoint_data_ref($fn, $i);
4544 # No line; delete them all.
4546 print $OUT "Deleting all breakpoints...\n";
4548 # %had_breakpoints lists every file that had at least one
4550 for my $file ( keys %had_breakpoints ) {
4552 # Switch to the desired file temporarily.
4553 local *dbline = $main::{ '_<' . $file };
4558 # For all lines in this file ...
4559 for ( $i = 1 ; $i <= $max ; $i++ ) {
4561 # If there's a breakpoint or action on this line ...
4562 if ( defined $dbline{$i} ) {
4564 # ... remove the breakpoint.
4565 $dbline{$i} =~ s/^[^\0]+//;
4566 if ( $dbline{$i} =~ s/^\0?$// ) {
4568 # Remove the entry altogether if no action is there.
4570 _delete_breakpoint_data_ref($file, $i);
4572 } ## end if (defined $dbline{$i...
4573 } ## end for ($i = 1 ; $i <= $max...
4575 # If, after we turn off the "there were breakpoints in this file"
4576 # bit, the entry in %had_breakpoints for this file is zero,
4577 # we should remove this file from the hash.
4578 if ( not $had_breakpoints{$file} &= ~1 ) {
4579 delete $had_breakpoints{$file};
4581 } ## end for my $file (keys %had_breakpoints)
4583 # Kill off all the other breakpoints that are waiting for files that
4584 # haven't been loaded yet.
4586 undef %postponed_file;
4587 undef %break_on_load;
4588 } ## end else [ if (defined($i))
4589 } ## end sub delete_breakpoint
4591 =head3 cmd_stop (command)
4593 This is meant to be part of the new command API, but it isn't called or used
4594 anywhere else in the debugger. XXX It is probably meant for use in development
4599 sub cmd_stop { # As on ^C, but not signal-safy.
4603 =head3 C<cmd_e> - threads
4605 Display the current thread id:
4609 This could be how (when implemented) to send commands to this thread id (e cmd)
4610 or that thread id (e tid cmd).
4617 unless (exists($INC{'threads.pm'})) {
4618 print "threads not loaded($ENV{PERL5DB_THREADED})
4619 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4621 my $tid = threads->tid;
4622 print "thread id: $tid\n";
4626 =head3 C<cmd_E> - list of thread ids
4628 Display the list of available thread ids:
4632 This could be used (when implemented) to send commands to all threads (E cmd).
4639 unless (exists($INC{'threads.pm'})) {
4640 print "threads not loaded($ENV{PERL5DB_THREADED})
4641 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4643 my $tid = threads->tid;
4644 print "thread ids: ".join(', ',
4645 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
4650 =head3 C<cmd_h> - help command (command)
4652 Does the work of either
4658 Showing all the debugger help
4662 Showing help for a specific command
4671 # If we have no operand, assume null.
4672 my $line = shift || '';
4674 # 'h h'. Print the long-format help.
4675 if ( $line =~ /^h\s*/ ) {
4679 # 'h <something>'. Search for the command and print only its help.
4680 elsif ( $line =~ /^(\S.*)$/ ) {
4682 # support long commands; otherwise bogus errors
4683 # happen when you ask for h on <CR> for example
4684 my $asked = $1; # the command requested
4685 # (for proper error message)
4687 my $qasked = quotemeta($asked); # for searching; we don't
4688 # want to use it as a pattern.
4689 # XXX: finds CR but not <CR>
4691 # Search the help string for the command.
4693 $help =~ /^ # Start of a line
4695 (?:[IB]<) # Optional markup
4696 $qasked # The requested command
4701 # It's there; pull it out and print it.
4705 (?:[IB]<) # Optional markup
4706 $qasked # The command
4707 ([\s\S]*?) # Description line(s)
4708 \n) # End of last description line
4709 (?!\s) # Next line not starting with
4718 # Not found; not a debugger command.
4720 print_help("B<$asked> is not a debugger command.\n");
4722 } ## end elsif ($line =~ /^(\S.*)$/)
4724 # 'h' - print the summary help.
4726 print_help($summary);
4730 =head3 C<cmd_i> - inheritance display
4732 Display the (nested) parentage of the module or object given.
4739 foreach my $isa ( split( /\s+/, $line ) ) {
4748 defined( ${"$_\::VERSION"} )
4749 ? ' ' . ${"$_\::VERSION"}
4751 } @{mro::get_linear_isa(ref($isa) || $isa)}
4757 =head3 C<cmd_l> - list lines (command)
4759 Most of the command is taken up with transforming all the different line
4760 specification syntaxes into 'start-stop'. After that is done, the command
4761 runs a loop over C<@dbline> for the specified range of lines. It handles
4762 the printing of each line and any markers (C<==E<gt>> for current line,
4763 C<b> for break on this line, C<a> for action on this line, C<:> for this
4766 We save the last line listed in the C<$start> global for further listing
4772 my $current_line = $line;
4776 # If this is '-something', delete any spaces after the dash.
4777 $line =~ s/^-\s*$/-/;
4779 # If the line is '$something', assume this is a scalar containing a
4781 if ( $line =~ /^(\$.*)/s ) {
4783 # Set up for DB::eval() - evaluate in *user* context.
4788 # Ooops. Bad scalar.
4789 print( $OUT "Error: $@\n" ), next CMD if $@;
4791 # Good scalar. If it's a reference, find what it points to.
4793 print( $OUT "Interpreted as: $1 $s\n" );
4796 # Call self recursively to really do the command.
4798 } ## end if ($line =~ /^(\$.*)/s)
4800 # l name. Try to find a sub by that name.
4801 elsif ( $line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s ) {
4802 my $s = $subname = $1;
4805 $subname =~ s/\'/::/;
4807 # Put it in this package unless it starts with ::.
4808 $subname = $package . "::" . $subname unless $subname =~ /::/;
4810 # Put it in CORE::GLOBAL if t doesn't start with :: and
4811 # it doesn't live in this package and it lives in CORE::GLOBAL.
4812 $subname = "CORE::GLOBAL::$s"
4813 if not defined &$subname
4815 and defined &{"CORE::GLOBAL::$s"};
4817 # Put leading '::' names into 'main::'.
4818 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4820 # Get name:start-stop from find_sub, and break this up at
4822 @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
4824 # Pull off start-stop.
4825 $subrange = pop @pieces;
4827 # If the name contained colons, the split broke it up.
4828 # Put it back together.
4829 $file = join( ':', @pieces );
4831 # If we're not in that file, switch over to it.
4832 if ( $file ne $filename ) {
4833 print $OUT "Switching to file '$file'.\n"
4834 unless $slave_editor;
4836 # Switch debugger's magic structures.
4837 *dbline = $main::{ '_<' . $file };
4840 } ## end if ($file ne $filename)
4842 # Subrange is 'start-stop'. If this is less than a window full,
4843 # swap it to 'start+', which will list a window from the start point.
4845 if ( eval($subrange) < -$window ) {
4846 $subrange =~ s/-.*/+/;
4849 # Call self recursively to list the range.
4851 &cmd_l( 'l', $subrange );
4852 } ## end if ($subrange)
4856 print $OUT "Subroutine $subname not found.\n";
4858 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
4861 elsif ( $line =~ /^\s*$/ ) {
4863 # Compute new range to list.
4864 $incr = $window - 1;
4865 $line = $start . '-' . ( $start + $incr );
4868 &cmd_l( 'l', $line );
4871 # l [start]+number_of_lines
4872 elsif ( $line =~ /^(\d*)\+(\d*)$/ ) {
4874 # Don't reset start for 'l +nnn'.
4877 # Increment for list. Use window size if not specified.
4878 # (Allows 'l +' to work.)
4880 $incr = $window - 1 unless $incr;
4882 # Create a line range we'll understand, and recurse to do it.
4883 $line = $start . '-' . ( $start + $incr );
4884 &cmd_l( 'l', $line );
4885 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
4887 # l start-stop or l start,stop
4888 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) {
4890 # Determine end point; use end of file if not specified.
4891 $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 );
4893 # Go on to the end, and then stop.
4894 $end = $max if $end > $max;
4896 # Determine start line.
4898 $i = $line if $i eq '.';
4902 # If we're running under a slave editor, force it to show the lines.
4903 if ($slave_editor) {
4904 print $OUT "\032\032$filename:$i:0\n";
4908 # We're doing it ourselves. We want to show the line and special
4910 # - the current line in execution
4911 # - whether a line is breakable or not
4912 # - whether a line has a break or not
4913 # - whether a line has an action or not
4915 for ( ; $i <= $end ; $i++ ) {
4917 # Check for breakpoints and actions.
4918 my ( $stop, $action );
4919 ( $stop, $action ) = split( /\0/, $dbline{$i} )
4922 # ==> if this is the current line in execution,
4923 # : if it's breakable.
4925 ( $i == $current_line and $filename eq $filename_ini )
4927 : ( $dbline[$i] + 0 ? ':' : ' ' );
4929 # Add break and action indicators.
4930 $arrow .= 'b' if $stop;
4931 $arrow .= 'a' if $action;
4934 print $OUT "$i$arrow\t", $dbline[$i];
4936 # Move on to the next line. Drop out on an interrupt.
4937 $i++, last if $signal;
4938 } ## end for (; $i <= $end ; $i++)
4940 # Line the prompt up; print a newline if the last line listed
4941 # didn't have a newline.
4942 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/;
4943 } ## end else [ if ($slave_editor)
4945 # Save the point we last listed to in case another relative 'l'
4946 # command is desired. Don't let it run off the end.
4948 $start = $max if $start > $max;
4949 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
4952 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
4954 To list breakpoints, the command has to look determine where all of them are
4955 first. It starts a C<%had_breakpoints>, which tells us what all files have
4956 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
4957 magic source and breakpoint data structures) to the file, and then look
4958 through C<%dbline> for lines with breakpoints and/or actions, listing them
4959 out. We look through C<%postponed> not-yet-compiled subroutines that have
4960 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
4961 that have breakpoints.
4963 Watchpoints are simpler: we just list the entries in C<@to_watch>.
4970 # If no argument, list everything. Pre-5.8.0 version always lists
4972 my $arg = shift || 'abw';
4973 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
4975 # See what is wanted.
4976 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0;
4977 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0;
4978 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0;
4980 # Breaks and actions are found together, so we look in the same place
4982 if ( $break_wanted or $action_wanted ) {
4984 # Look in all the files with breakpoints...
4985 for my $file ( keys %had_breakpoints ) {
4987 # Temporary switch to this file.
4988 local *dbline = $main::{ '_<' . $file };
4990 # Set up to look through the whole file.
4992 my $was; # Flag: did we print something
4995 # For each line in the file ...
4996 for ( $i = 1 ; $i <= $max ; $i++ ) {
4998 # We've got something on this line.
4999 if ( defined $dbline{$i} ) {
5001 # Print the header if we haven't.
5002 print $OUT "$file:\n" unless $was++;
5005 print $OUT " $i:\t", $dbline[$i];
5007 # Pull out the condition and the action.
5008 ( $stop, $action ) = split( /\0/, $dbline{$i} );
5010 # Print the break if there is one and it's wanted.
5011 print $OUT " break if (", $stop, ")\n"
5015 # Print the action if there is one and it's wanted.
5016 print $OUT " action: ", $action, "\n"
5020 # Quit if the user hit interrupt.
5022 } ## end if (defined $dbline{$i...
5023 } ## end for ($i = 1 ; $i <= $max...
5024 } ## end for my $file (keys %had_breakpoints)
5025 } ## end if ($break_wanted or $action_wanted)
5027 # Look for breaks in not-yet-compiled subs:
5028 if ( %postponed and $break_wanted ) {
5029 print $OUT "Postponed breakpoints in subroutines:\n";
5031 for $subname ( keys %postponed ) {
5032 print $OUT " $subname\t$postponed{$subname}\n";
5035 } ## end if (%postponed and $break_wanted)
5037 # Find files that have not-yet-loaded breaks:
5038 my @have = map { # Combined keys
5039 keys %{ $postponed_file{$_} }
5040 } keys %postponed_file;
5042 # If there are any, list them.
5043 if ( @have and ( $break_wanted or $action_wanted ) ) {
5044 print $OUT "Postponed breakpoints in files:\n";
5045 my ( $file, $line );
5047 for $file ( keys %postponed_file ) {
5048 my $db = $postponed_file{$file};
5049 print $OUT " $file:\n";
5050 for $line ( sort { $a <=> $b } keys %$db ) {
5051 print $OUT " $line:\n";
5052 my ( $stop, $action ) = split( /\0/, $$db{$line} );
5053 print $OUT " break if (", $stop, ")\n"
5056 print $OUT " action: ", $action, "\n"
5060 } ## end for $line (sort { $a <=>...
5062 } ## end for $file (keys %postponed_file)
5063 } ## end if (@have and ($break_wanted...
5064 if ( %break_on_load and $break_wanted ) {
5065 print $OUT "Breakpoints on load:\n";
5067 for $file ( keys %break_on_load ) {
5068 print $OUT " $file\n";
5071 } ## end if (%break_on_load and...
5072 if ($watch_wanted) {
5074 print $OUT "Watch-expressions:\n" if @to_watch;
5075 for my $expr (@to_watch) {
5076 print $OUT " $expr\n";
5079 } ## end if ($trace & 2)
5080 } ## end if ($watch_wanted)
5083 =head3 C<cmd_M> - list modules (command)
5085 Just call C<list_modules>.
5093 =head3 C<cmd_o> - options (command)
5095 If this is just C<o> by itself, we list the current settings via
5096 C<dump_option>. If there's a nonblank value following it, we pass that on to
5097 C<parse_options> for processing.
5103 my $opt = shift || ''; # opt[=val]
5105 # Nonblank. Try to parse and process.
5106 if ( $opt =~ /^(\S.*)/ ) {
5110 # Blank. List the current option settings.
5118 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5120 Advises the user that the O command has been renamed.
5125 print $OUT "The old O command is now the o command.\n"; # hint
5126 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5127 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5130 =head3 C<cmd_v> - view window (command)
5132 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5133 move back a few lines to list the selected line in context. Uses C<cmd_l>
5134 to do the actual listing after figuring out the range of line to request.
5142 # Extract the line to list around. (Astute readers will have noted that
5143 # this pattern will match whether or not a numeric line is specified,
5144 # which means that we'll always enter this loop (though a non-numeric
5145 # argument results in no action at all)).
5146 if ( $line =~ /^(\d*)$/ ) {
5148 # Total number of lines to list (a windowful).
5149 $incr = $window - 1;
5151 # Set the start to the argument given (if there was one).
5154 # Back up by the context amount.
5157 # Put together a linespec that cmd_l will like.
5158 $line = $start . '-' . ( $start + $incr );
5161 &cmd_l( 'l', $line );
5162 } ## end if ($line =~ /^(\d*)$/)
5165 =head3 C<cmd_w> - add a watch expression (command)
5167 The 5.8 version of this command adds a watch expression if one is specified;
5168 it does nothing if entered with no operands.
5170 We extract the expression, save it, evaluate it in the user's context, and
5171 save the value. We'll re-evaluate it each time the debugger passes a line,
5172 and will stop (see the code at the top of the command loop) if the value
5173 of any of the expressions changes.
5180 # Null expression if no arguments.
5181 my $expr = shift || '';
5183 # If expression is not null ...
5184 if ( $expr =~ /^(\S.*)/ ) {
5187 push @to_watch, $expr;
5189 # Parameterize DB::eval and call it to get the expression's value
5190 # in the user's context. This version can handle expressions which
5191 # return a list value.
5193 my ($val) = join( ' ', &eval );
5194 $val = ( defined $val ) ? "'$val'" : 'undef';
5196 # Save the current value of the expression.
5197 push @old_watch, $val;
5199 # We are now watching expressions.
5201 } ## end if ($expr =~ /^(\S.*)/)
5203 # You have to give one to get one.
5205 print $OUT "Adding a watch-expression requires an expression\n"; # hint
5209 =head3 C<cmd_W> - delete watch expressions (command)
5211 This command accepts either a watch expression to be removed from the list
5212 of watch expressions, or C<*> to delete them all.
5214 If C<*> is specified, we simply empty the watch expression list and the
5215 watch expression value list. We also turn off the bit that says we've got
5218 If an expression (or partial expression) is specified, we pattern-match
5219 through the expressions and remove the ones that match. We also discard
5220 the corresponding values. If no watch expressions are left, we turn off
5221 the I<watching expressions> bit.
5227 my $expr = shift || '';
5230 if ( $expr eq '*' ) {
5235 print $OUT "Deleting all watch expressions ...\n";
5238 @to_watch = @old_watch = ();
5241 # Delete one of them.
5242 elsif ( $expr =~ /^(\S.*)/ ) {
5244 # Where we are in the list.
5247 # For each expression ...
5248 foreach (@to_watch) {
5249 my $val = $to_watch[$i_cnt];
5251 # Does this one match the command argument?
5252 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
5253 # Yes. Turn it off, and its value too.
5254 splice( @to_watch, $i_cnt, 1 );
5255 splice( @old_watch, $i_cnt, 1 );
5258 } ## end foreach (@to_watch)
5260 # We don't bother to turn watching off because
5261 # a) we don't want to stop calling watchfunction() it it exists
5262 # b) foreach over a null list doesn't do anything anyway
5264 } ## end elsif ($expr =~ /^(\S.*)/)
5266 # No command arguments entered.
5269 "Deleting a watch-expression requires an expression, or '*' for all\n"
5274 ### END of the API section
5276 =head1 SUPPORT ROUTINES
5278 These are general support routines that are used in a number of places
5279 throughout the debugger.
5283 save() saves the user's versions of globals that would mess us up in C<@saved>,
5284 and installs the versions we like better.
5290 # Save eval failure, command failure, extended OS error, output field
5291 # separator, input record separator, output record separator and
5292 # the warning setting.
5293 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
5295 $, = ""; # output field separator is null string
5296 $/ = "\n"; # input record separator is newline
5297 $\ = ""; # output record separator is null string
5298 $^W = 0; # warnings are off
5301 =head2 C<print_lineinfo> - show where we are now
5303 print_lineinfo prints whatever it is that it is handed; it prints it to the
5304 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5305 us to feed line information to a slave editor without messing up the
5310 sub print_lineinfo {
5312 # Make the terminal sensible if we're not the primary debugger.
5313 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5317 } ## end sub print_lineinfo
5319 =head2 C<postponed_sub>
5321 Handles setting postponed breakpoints in subroutines once they're compiled.
5322 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5323 range for the subroutine, then mark the file as having a breakpoint,
5324 temporarily switch the C<*dbline> glob over to the source file, and then
5325 search the given range of lines to find a breakable line. If we find one,
5326 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
5330 # The following takes its argument via $evalarg to preserve current @_
5334 # Get the subroutine name.
5335 my $subname = shift;
5337 # If this is a 'break +<n> if <condition>' ...
5338 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
5340 # If there's no offset, use '+0'.
5341 my $offset = $1 || 0;
5343 # find_sub's value is 'fullpath-filename:start-stop'. It's
5344 # possible that the filename might have colons in it too.
5345 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
5348 # We got the start line. Add the offset '+<n>' from
5349 # $postponed{subname}.
5352 # Switch to the file this sub is in, temporarily.
5353 local *dbline = $main::{ '_<' . $file };
5355 # No warnings, please.
5356 local $^W = 0; # != 0 is magical below
5358 # This file's got a breakpoint in it.
5359 $had_breakpoints{$file} |= 1;
5361 # Last line in file.
5364 # Search forward until we hit a breakable line or get to
5365 # the end of the file.
5366 ++$i until $dbline[$i] != 0 or $i >= $max;
5368 # Copy the breakpoint in and delete it from %postponed.
5369 $dbline{$i} = delete $postponed{$subname};
5372 # find_sub didn't find the sub.
5375 print $OUT "Subroutine $subname not found.\n";
5378 } ## end if ($postponed{$subname...
5379 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
5381 #print $OUT "In postponed_sub for '$subname'.\n";
5382 } ## end sub postponed_sub
5386 Called after each required file is compiled, but before it is executed;
5387 also called if the name of a just-compiled subroutine is a key of
5388 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
5389 etc.) into the just-compiled code.
5391 If this is a C<require>'d file, the incoming parameter is the glob
5392 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
5394 If it's a subroutine, the incoming parameter is the subroutine name.
5400 # If there's a break, process it.
5401 if ($ImmediateStop) {
5403 # Right, we've stopped. Turn it off.
5406 # Enter the command loop when DB::DB gets called.
5410 # If this is a subroutine, let postponed_sub() deal with it.
5411 return &postponed_sub unless ref \$_[0] eq 'GLOB';
5413 # Not a subroutine. Deal with the file.
5414 local *dbline = shift;
5415 my $filename = $dbline;
5416 $filename =~ s/^_<//;
5418 $signal = 1, print $OUT "'$filename' loaded...\n"
5419 if $break_on_load{$filename};
5420 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
5422 # Do we have any breakpoints to put in this file?
5423 return unless $postponed_file{$filename};
5425 # Yes. Mark this file as having breakpoints.
5426 $had_breakpoints{$filename} |= 1;
5428 # "Cannot be done: insufficient magic" - we can't just put the
5429 # breakpoints saved in %postponed_file into %dbline by assigning
5430 # the whole hash; we have to do it one item at a time for the
5431 # breakpoints to be set properly.
5432 #%dbline = %{$postponed_file{$filename}};
5434 # Set the breakpoints, one at a time.
5437 for $key ( keys %{ $postponed_file{$filename} } ) {
5439 # Stash the saved breakpoint into the current file's magic line array.
5440 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
5443 # This file's been compiled; discard the stored breakpoints.
5444 delete $postponed_file{$filename};
5446 } ## end sub postponed
5450 C<dumpit> is the debugger's wrapper around dumpvar.pl.
5452 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
5453 a reference to a variable (the thing to be dumped) as its input.
5455 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
5456 the currently-selected filehandle, thank you very much). The current
5457 values of the package globals C<$single> and C<$trace> are backed up in
5458 lexicals, and they are turned off (this keeps the debugger from trying
5459 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
5460 preserve its current value and it is set to zero to prevent entry/exit
5461 messages from printing, and C<$doret> is localized as well and set to -2 to
5462 prevent return values from being shown.
5464 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
5465 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
5466 installed version in C<@INC>, yours will be used instead. Possible security
5469 It then checks to see if the subroutine C<main::dumpValue> is now defined
5470 (it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
5471 localizes the globals necessary for things to be sane when C<main::dumpValue()>
5472 is called, and picks up the variable to be dumped from the parameter list.
5474 It checks the package global C<%options> to see if there's a C<dumpDepth>
5475 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
5476 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
5477 structure: -1 means dump everything.
5479 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
5482 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
5483 and we then return to the caller.
5489 # Save the current output filehandle and switch to the one
5490 # passed in as the first parameter.
5491 local ($savout) = select(shift);
5493 # Save current settings of $single and $trace, and then turn them off.
5494 my $osingle = $single;
5495 my $otrace = $trace;
5496 $single = $trace = 0;
5498 # XXX Okay, what do $frame and $doret do, again?
5502 # Load dumpvar.pl unless we've already got the sub we need from it.
5503 unless ( defined &main::dumpValue ) {
5504 do 'dumpvar.pl' or die $@;
5507 # If the load succeeded (or we already had dumpvalue()), go ahead
5509 if ( defined &main::dumpValue ) {
5514 my $maxdepth = shift || $option{dumpDepth};
5515 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
5516 &main::dumpValue( $v, $maxdepth );
5517 } ## end if (defined &main::dumpValue)
5519 # Oops, couldn't load dumpvar.pl.
5522 print $OUT "dumpvar.pl not available.\n";
5525 # Reset $single and $trace to their old values.
5529 # Restore the old filehandle.
5533 =head2 C<print_trace>
5535 C<print_trace>'s job is to print a stack trace. It does this via the
5536 C<dump_trace> routine, which actually does all the ferreting-out of the
5537 stack trace data. C<print_trace> takes care of formatting it nicely and
5538 printing it to the proper filehandle.
5546 The filehandle to print to.
5550 How many frames to skip before starting trace.
5554 How many frames to print.
5558 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
5562 The original comment below seems to be noting that the traceback may not be
5563 correct if this routine is called in a tied method.
5567 # Tied method do not create a context, so may get wrong message:
5573 # If this is going to a slave editor, but we're not the primary
5574 # debugger, reset it first.
5576 if $fh eq $LINEINFO # slave editor
5577 and $LINEINFO eq $OUT # normal output
5578 and $term_pid != $$; # not the primary
5580 # Collect the actual trace information to be formatted.
5581 # This is an array of hashes of subroutine call info.
5582 my @sub = dump_trace( $_[0] + 1, $_[1] );
5584 # Grab the "short report" flag from @_.
5585 my $short = $_[2]; # Print short report, next one for sub name
5587 # Run through the traceback info, format it, and print it.
5589 for ( $i = 0 ; $i <= $#sub ; $i++ ) {
5591 # Drop out if the user has lost interest and hit control-C.
5594 # Set the separator so arrys print nice.
5597 # Grab and stringify the arguments if they are there.
5599 defined $sub[$i]{args}
5600 ? "(@{ $sub[$i]{args} })"
5603 # Shorten them up if $maxtrace says they're too long.
5604 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
5605 if length $args > $maxtrace;
5607 # Get the file name.
5608 my $file = $sub[$i]{file};
5610 # Put in a filename header if short is off.
5611 $file = $file eq '-e' ? $file : "file '$file'" unless $short;
5613 # Get the actual sub's name, and shorten to $maxtrace's requirement.
5615 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
5617 # Short report uses trimmed file and sub names.
5619 my $sub = @_ >= 4 ? $_[3] : $s;
5620 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
5621 } ## end if ($short)
5623 # Non-short report includes full names.
5625 print $fh "$sub[$i]{context} = $s$args"
5626 . " called from $file"
5627 . " line $sub[$i]{line}\n";
5629 } ## end for ($i = 0 ; $i <= $#sub...
5630 } ## end sub print_trace
5632 =head2 dump_trace(skip[,count])
5634 Actually collect the traceback information available via C<caller()>. It does
5635 some filtering and cleanup of the data, but mostly it just collects it to
5636 make C<print_trace()>'s job easier.
5638 C<skip> defines the number of stack frames to be skipped, working backwards
5639 from the most current. C<count> determines the total number of frames to
5640 be returned; all of them (well, the first 10^9) are returned if C<count>
5643 This routine returns a list of hashes, from most-recent to least-recent
5644 stack frame. Each has the following keys and values:
5648 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
5650 =item * C<sub> - subroutine name, or C<eval> information
5652 =item * C<args> - undef, or a reference to an array of arguments
5654 =item * C<file> - the file in which this item was defined (if any)
5656 =item * C<line> - the line on which it was defined
5664 # How many levels to skip.
5667 # How many levels to show. (1e9 is a cheap way of saying "all of them";
5668 # it's unlikely that we'll have more than a billion stack frames. If you
5669 # do, you've got an awfully big machine...)
5670 my $count = shift || 1e9;
5672 # We increment skip because caller(1) is the first level *back* from
5673 # the current one. Add $skip to the count of frames so we have a
5674 # simple stop criterion, counting from $skip to $count+$skip.
5678 # These variables are used to capture output from caller();
5679 my ( $p, $file, $line, $sub, $h, $context );
5681 my ( $e, $r, @a, @sub, $args );
5683 # XXX Okay... why'd we do that?
5684 my $nothard = not $frame & 8;
5687 # Do not want to trace this.
5688 my $otrace = $trace;
5691 # Start out at the skip count.
5692 # If we haven't reached the number of frames requested, and caller() is
5693 # still returning something, stay in the loop. (If we pass the requested
5694 # number of stack frames, or we run out - caller() returns nothing - we
5696 # Up the stack frame index to go back one more level each time.
5700 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
5705 # Go through the arguments and save them for later.
5709 if ( not defined $arg ) { # undefined parameter
5713 elsif ( $nothard and tied $arg ) { # tied parameter
5716 elsif ( $nothard and $type = ref $arg ) { # reference
5717 push @a, "ref($type)";
5719 else { # can be stringified
5721 "$arg"; # Safe to stringify now - should not call f().
5723 # Backslash any single-quotes or backslashes.
5726 # Single-quote it unless it's a number or a colon-separated
5729 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
5731 # Turn high-bit characters into meta-whatever.
5732 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
5734 # Turn control characters into ^-whatever.
5735 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
5738 } ## end else [ if (not defined $arg)
5739 } ## end for $arg (@args)
5741 # If context is true, this is array (@)context.
5742 # If context is false, this is scalar ($) context.
5743 # If neither, context isn't defined. (This is apparently a 'can't
5745 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
5747 # if the sub has args ($h true), make an anonymous array of the
5749 $args = $h ? [@a] : undef;
5751 # remove trailing newline-whitespace-semicolon-end of line sequence
5752 # from the eval text, if any.
5753 $e =~ s/\n\s*\;\s*\Z// if $e;
5755 # Escape backslashed single-quotes again if necessary.
5756 $e =~ s/([\\\'])/\\$1/g if $e;
5758 # if the require flag is true, the eval text is from a require.
5760 $sub = "require '$e'";
5763 # if it's false, the eval text is really from an eval.
5764 elsif ( defined $r ) {
5768 # If the sub is '(eval)', this is a block eval, meaning we don't
5769 # know what the eval'ed text actually was.
5770 elsif ( $sub eq '(eval)' ) {
5771 $sub = "eval {...}";
5774 # Stick the collected information into @sub as an anonymous hash.
5778 context => $context,
5786 # Stop processing frames if the user hit control-C.
5788 } ## end for ($i = $skip ; $i < ...
5790 # Restore the trace value again.
5793 } ## end sub dump_trace
5797 C<action()> takes input provided as the argument to an add-action command,
5798 either pre- or post-, and makes sure it's a complete command. It doesn't do
5799 any fancy parsing; it just keeps reading input until it gets a string
5800 without a trailing backslash.
5807 while ( $action =~ s/\\$// ) {
5809 # We have a backslash on the end. Read more.
5811 } ## end while ($action =~ s/\\$//)
5813 # Return the assembled action.
5819 This routine mostly just packages up a regular expression to be used
5820 to check that the thing it's being matched against has properly-matched
5823 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
5824 speeds things up by only creating the qr//'ed expression once; if it's
5825 already defined, we don't try to define it again. A speed hack.
5831 # I hate using globals!
5832 $balanced_brace_re ||= qr{
5835 (?> [^{}] + ) # Non-parens without backtracking
5837 (??{ $balanced_brace_re }) # Group with matching parens
5841 return $_[0] !~ m/$balanced_brace_re/;
5842 } ## end sub unbalanced
5846 C<gets()> is a primitive (very primitive) routine to read continuations.
5847 It was devised for reading continuations for actions.
5848 it just reads more input with C<readline()> and returns it.
5853 &readline("cont: ");
5856 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger
5858 The C<system()> function assumes that it can just go ahead and use STDIN and
5859 STDOUT, but under the debugger, we want it to use the debugger's input and
5862 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes
5863 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
5864 and then puts everything back again.
5870 # We save, change, then restore STDIN and STDOUT to avoid fork() since
5871 # some non-Unix systems can do system() but have problems with fork().
5872 open( SAVEIN, "<&STDIN" ) || &warn("Can't save STDIN");
5873 open( SAVEOUT, ">&STDOUT" ) || &warn("Can't save STDOUT");
5874 open( STDIN, "<&IN" ) || &warn("Can't redirect STDIN");
5875 open( STDOUT, ">&OUT" ) || &warn("Can't redirect STDOUT");
5877 # XXX: using csh or tcsh destroys sigint retvals!
5879 open( STDIN, "<&SAVEIN" ) || &warn("Can't restore STDIN");
5880 open( STDOUT, ">&SAVEOUT" ) || &warn("Can't restore STDOUT");
5884 # most of the $? crud was coping with broken cshisms
5886 &warn( "(Command exited ", ( $? >> 8 ), ")\n" );
5890 "(Command died of SIG#",
5892 ( ( $? & 128 ) ? " -- core dumped" : "" ),
5901 =head1 TTY MANAGEMENT
5903 The subs here do some of the terminal management for multiple debuggers.
5907 Top-level function called when we want to set up a new terminal for use
5910 If the C<noTTY> debugger option was set, we'll either use the terminal
5911 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
5912 to find one. If we're a forked debugger, we call C<resetterm> to try to
5913 get a whole new terminal if we can.
5915 In either case, we set up the terminal next. If the C<ReadLine> option was
5916 true, we'll get a C<Term::ReadLine> object for the current terminal and save
5917 the appropriate attributes. We then
5923 # Load Term::Readline, but quietly; don't debug it and don't trace it.
5926 require Term::ReadLine;
5928 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
5931 my ( $i, $o ) = split $tty, /,/;
5932 $o = $i unless defined $o;
5933 open( IN, "<$i" ) or die "Cannot open TTY '$i' for read: $!";
5934 open( OUT, ">$o" ) or die "Cannot open TTY '$o' for write: $!";
5937 my $sel = select($OUT);
5942 # We don't have a TTY - try to find one via Term::Rendezvous.
5944 require Term::Rendezvous;
5946 # See if we have anything to pass to Term::Rendezvous.
5947 # Use $HOME/.perldbtty$$ if not.
5948 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
5950 # Rendezvous and get the filehandles.
5951 my $term_rv = Term::Rendezvous->new( $rv );
5953 $OUT = $term_rv->OUT;
5954 } ## end else [ if ($tty)
5955 } ## end if ($notty)
5957 # We're a daughter debugger. Try to fork off another TTY.
5958 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
5962 # If we shouldn't use Term::ReadLine, don't.
5964 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
5967 # We're using Term::ReadLine. Get all the attributes for this terminal.
5969 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
5971 $rl_attribs = $term->Attribs;
5972 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
5973 if defined $rl_attribs->{basic_word_break_characters}
5974 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
5975 $rl_attribs->{special_prefixes} = '$@&%';
5976 $rl_attribs->{completer_word_break_characters} .= '$@&%';
5977 $rl_attribs->{completion_function} = \&db_complete;
5978 } ## end else [ if (!$rl)
5980 # Set up the LINEINFO filehandle.
5981 $LINEINFO = $OUT unless defined $LINEINFO;
5982 $lineinfo = $console unless defined $lineinfo;
5988 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
5989 $term->SetHistory(@hist);
5992 # XXX Ornaments are turned on unconditionally, which is not
5993 # always a good thing.
5994 ornaments($ornaments) if defined $ornaments;
5996 } ## end sub setterm
5999 $histfile //= option_val("HistFile", undef);
6000 return unless defined $histfile;
6001 open my $fh, "<", $histfile or return;
6012 return unless defined $histfile;
6013 eval { require File::Path } or return;
6014 eval { require File::Basename } or return;
6015 File::Path::mkpath(File::Basename::dirname($histfile));
6016 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6017 $histsize //= option_val("HistSize",100);
6018 my @copy = grep { $_ ne '?' } @hist;
6019 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6020 for ($start .. $#copy) {
6021 print $fh "$copy[$_]\n";
6023 close $fh or die "Could not write '$histfile': $!";
6026 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6028 When the process being debugged forks, or the process invokes a command
6029 via C<system()> which starts a new debugger, we need to be able to get a new
6030 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6031 fight over the terminal, and you can never quite be sure who's going to get the
6032 input you're typing.
6034 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6035 is tasked with doing all the necessary operating system mojo to get a new
6036 TTY (and probably another window) and to direct the new debugger to read and
6039 The debugger provides C<get_fork_TTY> functions which work for TCP
6040 socket servers, X11, OS/2, and Mac OS X. Other systems are not
6041 supported. You are encouraged to write C<get_fork_TTY> functions which
6042 work for I<your> platform and contribute them.
6044 =head3 C<socket_get_fork_TTY>
6048 sub connect_remoteport {
6051 my $socket = IO::Socket::INET->new(
6053 PeerAddr => $remoteport,
6057 die "Unable to connect to remote host: $remoteport\n";
6062 sub socket_get_fork_TTY {
6063 $tty = $LINEINFO = $IN = $OUT = connect_remoteport();
6065 # Do I need to worry about setting $term?
6067 reset_IN_OUT( $IN, $OUT );
6071 =head3 C<xterm_get_fork_TTY>
6073 This function provides the C<get_fork_TTY> function for X11. If a
6074 program running under the debugger forks, a new <xterm> window is opened and
6075 the subsidiary debugger is directed there.
6077 The C<open()> call is of particular note here. We have the new C<xterm>
6078 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6079 command (which prints the device name of the TTY we'll want to use for input
6080 and output to STDOUT, then C<sleep> for a very long time, routing this output
6081 to file number 3. This way we can simply read from the <XT> filehandle (which
6082 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6084 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6089 sub xterm_get_fork_TTY {
6090 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6092 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6095 # Get the output from 'tty' and clean it up a little.
6099 $pidprompt = ''; # Shown anyway in titlebar
6101 # We need $term defined or we can not switch to the newly created xterm
6102 if ($tty ne '' && !defined $term) {
6103 require Term::ReadLine;
6105 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6108 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6111 # There's our new TTY.
6113 } ## end sub xterm_get_fork_TTY
6115 =head3 C<os2_get_fork_TTY>
6117 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6121 # This example function resets $IN, $OUT itself
6123 sub os2_get_fork_TTY { # A simplification of the following (and works without):
6125 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6126 my %opt = ( title => "Daughter Perl debugger $pids $name",
6127 ($rl ? (read_by_key => 1) : ()) );
6128 require OS2::Process;
6129 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
6131 $pidprompt = ''; # Shown anyway in titlebar
6132 reset_IN_OUT($in, $out);
6134 return ''; # Indicate that reset_IN_OUT is called
6135 } ## end sub os2_get_fork_TTY
6137 =head3 C<macosx_get_fork_TTY>
6139 The Mac OS X version uses AppleScript to tell Terminal.app to create
6144 # Notes about Terminal.app's AppleScript support,
6145 # (aka things that might break in future OS versions).
6147 # The "do script" command doesn't return a reference to the new window
6148 # it creates, but since it appears frontmost and windows are enumerated
6149 # front to back, we can use "first window" === "window 1".
6151 # Since "do script" is implemented by supplying the argument (plus a
6152 # return character) as terminal input, there's a potential race condition
6153 # where the debugger could beat the shell to reading the command.
6154 # To prevent this, we wait for the screen to clear before proceeding.
6157 # There's no direct accessor for the tty device name, so we fiddle
6158 # with the window title options until it says what we want.
6161 # There _is_ a direct accessor for the tty device name, _and_ there's
6162 # a new possible component of the window title (the name of the settings
6163 # set). A separate version is needed.
6165 my @script_versions=
6167 ([237, <<'__LEOPARD__'],
6168 tell application "Terminal"
6169 do script "clear;exec sleep 100000"
6170 tell first tab of first window
6172 set custom title to "forked perl debugger"
6173 set title displays custom title to true
6174 repeat while (length of first paragraph of (get contents)) > 0
6182 [100, <<'__JAGUAR_TIGER__'],
6183 tell application "Terminal"
6184 do script "clear;exec sleep 100000"
6186 set title displays shell path to false
6187 set title displays window size to false
6188 set title displays file name to false
6189 set title displays device name to true
6190 set title displays custom title to true
6191 set custom title to ""
6192 copy "/dev/" & name to thetty
6193 set custom title to "forked perl debugger"
6194 repeat while (length of first paragraph of (get contents)) > 0
6204 sub macosx_get_fork_TTY
6206 my($version,$script,$pipe,$tty);
6208 return unless $version=$ENV{TERM_PROGRAM_VERSION};
6209 foreach my $entry (@script_versions) {
6210 if ($version>=$entry->[0]) {
6211 $script=$entry->[1];
6215 return unless defined($script);
6216 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
6217 $tty=readline($pipe);
6219 return unless defined($tty) && $tty =~ m(^/dev/);
6224 =head2 C<create_IN_OUT($flags)>
6226 Create a new pair of filehandles, pointing to a new TTY. If impossible,
6227 try to diagnose why.
6233 =item * 1 - Don't know how to create a new TTY.
6235 =item * 2 - Debugger has forked, but we can't get a new TTY.
6237 =item * 4 - standard debugger startup is happening.
6243 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
6245 # If we know how to get a new TTY, do it! $in will have
6246 # the TTY name if get_fork_TTY works.
6247 my $in = &get_fork_TTY if defined &get_fork_TTY;
6249 # It used to be that
6250 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
6252 if ( not defined $in ) {
6255 # We don't know how.
6256 print_help(<<EOP) if $why == 1;
6257 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6261 print_help(<<EOP) if $why == 2;
6262 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6263 This may be an asynchronous session, so the parent debugger may be active.
6266 # Note that both debuggers are fighting over the same input.
6267 print_help(<<EOP) if $why != 4;
6268 Since two debuggers fight for the same TTY, input is severely entangled.
6272 I know how to switch the output to a different window in xterms, OS/2
6273 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
6274 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
6275 B<DB::get_fork_TTY()> returning this.
6277 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6278 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6281 } ## end if (not defined $in)
6282 elsif ( $in ne '' ) {
6286 $console = ''; # Indicate no need to open-from-the-console
6289 } ## end sub create_IN_OUT
6293 Handles rejiggering the prompt when we've forked off a new debugger.
6295 If the new debugger happened because of a C<system()> that invoked a
6296 program under the debugger, the arrow between the old pid and the new
6297 in the prompt has I<two> dashes instead of one.
6299 We take the current list of pids and add this one to the end. If there
6300 isn't any list yet, we make one up out of the initial pid associated with
6301 the terminal and our new pid, sticking an arrow (either one-dashed or
6302 two dashed) in between them.
6304 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6305 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6310 sub resetterm { # We forked, so we need a different TTY
6312 # Needs to be passed to create_IN_OUT() as well.
6315 # resetterm(2): got in here because of a system() starting a debugger.
6316 # resetterm(1): just forked.
6317 my $systemed = $in > 1 ? '-' : '';
6319 # If there's already a list of pids, add this to the end.
6321 $pids =~ s/\]/$systemed->$$]/;
6324 # No pid list. Time to make one.
6326 $pids = "[$term_pid->$$]";
6329 # The prompt we're going to be using for this debugger.
6332 # We now 0wnz this terminal.
6335 # Just return if we're not supposed to try to create a new TTY.
6336 return unless $CreateTTY & $in;
6338 # Try to create a new IN/OUT pair.
6340 } ## end sub resetterm
6344 First, we handle stuff in the typeahead buffer. If there is any, we shift off
6345 the next line, print a message saying we got it, add it to the terminal
6346 history (if possible), and return it.
6348 If there's nothing in the typeahead buffer, check the command filehandle stack.
6349 If there are any filehandles there, read from the last one, and return the line
6350 if we got one. If not, we pop the filehandle off and close it, and try the
6351 next one up the stack.
6353 If we've emptied the filehandle stack, we check to see if we've got a socket
6354 open, and we read that and return it if we do. If we don't, we just call the
6355 core C<readline()> and return its value.
6361 # Localize to prevent it from being smashed in the program being debugged.
6364 # Pull a line out of the typeahead if there's stuff there.
6367 # How many lines left.
6368 my $left = @typeahead;
6370 # Get the next line.
6371 my $got = shift @typeahead;
6373 # Print a message saying we got input from the typeahead.
6375 print $OUT "auto(-$left)", shift, $got, "\n";
6377 # Add it to the terminal history (if possible).
6378 $term->AddHistory($got)
6380 and defined $term->Features->{addHistory};
6382 } ## end if (@typeahead)
6384 # We really need to read some input. Turn off entry/exit trace and
6385 # return value printing.
6389 # If there are stacked filehandles to read from ...
6392 # Read from the last one in the stack.
6393 my $line = CORE::readline( $cmdfhs[-1] );
6395 # If we got a line ...
6397 ? ( print $OUT ">> $line" and return $line ) # Echo and return
6398 : close pop @cmdfhs; # Pop and close
6399 } ## end while (@cmdfhs)
6401 # Nothing on the filehandle stack. Socket?
6402 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
6404 # Send anything we have to send.
6405 $OUT->write( join( '', @_ ) );
6407 # Receive anything there is to receive.
6412 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
6413 # XXX Don't know. You tell me.
6414 } while length $buf and ($stuff .= $buf) !~ /\n/;
6418 } ## end if (ref $OUT and UNIVERSAL::isa...
6420 # No socket. Just read from the terminal.
6422 $term->readline(@_);
6424 } ## end sub readline
6426 =head1 OPTIONS SUPPORT ROUTINES
6428 These routines handle listing and setting option values.
6430 =head2 C<dump_option> - list the current value of an option setting
6432 This routine uses C<option_val> to look up the value for an option.
6433 It cleans up escaped single-quotes and then displays the option and
6439 my ( $opt, $val ) = @_;
6440 $val = option_val( $opt, 'N/A' );
6441 $val =~ s/([\\\'])/\\$1/g;
6442 printf $OUT "%20s = '%s'\n", $opt, $val;
6443 } ## end sub dump_option
6445 sub options2remember {
6446 foreach my $k (@RememberOnROptions) {
6447 $option{$k} = option_val( $k, 'N/A' );
6452 =head2 C<option_val> - find the current value of an option
6454 This can't just be a simple hash lookup because of the indirect way that
6455 the option values are stored. Some are retrieved by calling a subroutine,
6456 some are just variables.
6458 You must supply a default value to be used in case the option isn't set.
6463 my ( $opt, $default ) = @_;
6466 # Does this option exist, and is it a variable?
6467 # If so, retrieve the value via the value in %optionVars.
6468 if ( defined $optionVars{$opt}
6469 and defined ${ $optionVars{$opt} } )
6471 $val = ${ $optionVars{$opt} };
6474 # Does this option exist, and it's a subroutine?
6475 # If so, call the subroutine via the ref in %optionAction
6476 # and capture the value.
6477 elsif ( defined $optionAction{$opt}
6478 and defined &{ $optionAction{$opt} } )
6480 $val = &{ $optionAction{$opt} }();
6483 # If there's an action or variable for the supplied option,
6484 # but no value was set, use the default.
6485 elsif (defined $optionAction{$opt} and not defined $option{$opt}
6486 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
6491 # Otherwise, do the simple hash lookup.
6493 $val = $option{$opt};
6496 # If the value isn't defined, use the default.
6497 # Then return whatever the value is.
6498 $val = $default unless defined $val;
6500 } ## end sub option_val
6502 =head2 C<parse_options>
6504 Handles the parsing and execution of option setting/displaying commands.
6506 An option entered by itself is assumed to be I<set me to 1> (the default value)
6507 if the option is a boolean one. If not, the user is prompted to enter a valid
6508 value or to query the current value (via C<option? >).
6510 If C<option=value> is entered, we try to extract a quoted string from the
6511 value (if it is quoted). If it's not, we just use the whole value as-is.
6513 We load any modules required to service this option, and then we set it: if
6514 it just gets stuck in a variable, we do that; if there's a subroutine to
6515 handle setting the option, we call that.
6517 Finally, if we're running in interactive mode, we display the effect of the
6518 user's command back to the terminal, skipping this if we're setting things
6519 during initialization.
6527 # These options need a value. Don't allow them to be clobbered by accident.
6528 my %opt_needs_val = map { ( $_ => 1 ) } qw{
6529 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
6530 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
6536 # Clean off excess leading whitespace.
6539 # Options are always all word characters, followed by a non-word
6541 s/^(\w+)(\W?)// or print( $OUT "Invalid option '$_'\n" ), last;
6542 my ( $opt, $sep ) = ( $1, $2 );
6544 # Make sure that such an option exists.
6545 my $matches = grep( /^\Q$opt/ && ( $option = $_ ), @options )
6546 || grep( /^\Q$opt/i && ( $option = $_ ), @options );
6548 print( $OUT "Unknown option '$opt'\n" ), next unless $matches;
6549 print( $OUT "Ambiguous option '$opt'\n" ), next if $matches > 1;
6552 # '?' as separator means query, but must have whitespace after it.
6553 if ( "?" eq $sep ) {
6554 print( $OUT "Option query '$opt?' followed by non-space '$_'\n" ),
6558 #&dump_option($opt);
6559 } ## end if ("?" eq $sep)
6561 # Separator is whitespace (or just a carriage return).
6562 # They're going for a default, which we assume is 1.
6563 elsif ( $sep !~ /\S/ ) {
6565 $val = "1"; # this is an evil default; make 'em set it!
6568 # Separator is =. Trying to set a value.
6569 elsif ( $sep eq "=" ) {
6571 # If quoted, extract a quoted string.
6572 if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
6574 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
6577 # Not quoted. Use the whole thing. Warn about 'option='.
6581 print OUT qq(Option better cleared using $opt=""\n)
6583 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
6585 } ## end elsif ($sep eq "=")
6587 # "Quoted" with [], <>, or {}.
6588 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
6590 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
6591 s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
6592 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last;
6593 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
6594 } ## end else [ if ("?" eq $sep)
6596 # Exclude non-booleans from getting set to 1 by default.
6597 if ( $opt_needs_val{$option} && $val_defaulted ) {
6598 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
6600 "Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n";
6602 } ## end if ($opt_needs_val{$option...
6604 # Save the option value.
6605 $option{$option} = $val if defined $val;
6607 # Load any module that this option requires.
6611 require '$optionRequire{$option}';
6613 } || die $@ # XXX: shouldn't happen
6614 if defined $optionRequire{$option}
6618 # Stick it in the proper variable if it goes in a variable.
6619 ${ $optionVars{$option} } = $val
6620 if defined $optionVars{$option}
6623 # Call the appropriate sub if it gets set via sub.
6624 &{ $optionAction{$option} }($val)
6625 if defined $optionAction{$option}
6626 && defined &{ $optionAction{$option} }
6629 # Not initialization - echo the value we set it to.
6630 dump_option($option) unless $OUT eq \*STDERR;
6631 } ## end while (length)
6632 } ## end sub parse_options
6634 =head1 RESTART SUPPORT
6636 These routines are used to store (and restore) lists of items in environment
6637 variables during a restart.
6641 Set_list packages up items to be stored in a set of environment variables
6642 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
6643 the values). Values outside the standard ASCII charset are stored by encoding
6644 then as hexadecimal values.
6649 my ( $stem, @list ) = @_;
6652 # VAR_n: how many we have. Scalar assignment gets the number of items.
6653 $ENV{"${stem}_n"} = @list;
6655 # Grab each item in the list, escape the backslashes, encode the non-ASCII
6656 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
6657 for $i ( 0 .. $#list ) {
6659 $val =~ s/\\/\\\\/g;
6660 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
6661 $ENV{"${stem}_$i"} = $val;
6662 } ## end for $i (0 .. $#list)
6663 } ## end sub set_list
6667 Reverse the set_list operation: grab VAR_n to see how many we should be getting
6668 back, and then pull VAR_0, VAR_1. etc. back out.
6675 my $n = delete $ENV{"${stem}_n"};
6677 for $i ( 0 .. $n - 1 ) {
6678 $val = delete $ENV{"${stem}_$i"};
6679 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
6683 } ## end sub get_list
6685 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
6689 The C<catch()> subroutine is the essence of fast and low-impact. We simply
6690 set an already-existing global scalar variable to a constant value. This
6691 avoids allocating any memory possibly in the middle of something that will
6692 get all confused if we do, particularly under I<unsafe signals>.
6698 return; # Put nothing on the stack - malloc/free land!
6703 C<warn> emits a warning, by joining together its arguments and printing
6704 them, with couple of fillips.
6706 If the composited message I<doesn't> end with a newline, we automatically
6707 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
6708 to be set to the filehandle to be used to output warnings; it makes no
6709 assumptions about what filehandles are available.
6714 my ($msg) = join( "", @_ );
6715 $msg .= ": $!\n" unless $msg =~ /\n$/;
6720 =head1 INITIALIZATION TTY SUPPORT
6722 =head2 C<reset_IN_OUT>
6724 This routine handles restoring the debugger's input and output filehandles
6725 after we've tried and failed to move them elsewhere. In addition, it assigns
6726 the debugger's output filehandle to $LINEINFO if it was already open there.
6731 my $switch_li = $LINEINFO eq $OUT;
6733 # If there's a term and it's able to get a new tty, try to get one.
6734 if ( $term and $term->Features->{newTTY} ) {
6735 ( $IN, $OUT ) = ( shift, shift );
6736 $term->newTTY( $IN, $OUT );
6739 # This term can't get a new tty now. Better luck later.
6741 &warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n");
6744 # Set the filehndles up as they were.
6746 ( $IN, $OUT ) = ( shift, shift );
6749 # Unbuffer the output filehandle.
6750 my $o = select $OUT;
6754 # Point LINEINFO to the same output filehandle if it was there before.
6755 $LINEINFO = $OUT if $switch_li;
6756 } ## end sub reset_IN_OUT
6758 =head1 OPTION SUPPORT ROUTINES
6760 The following routines are used to process some of the more complicated
6765 Sets the input and output filehandles to the specified files or pipes.
6766 If the terminal supports switching, we go ahead and do it. If not, and
6767 there's already a terminal in place, we save the information to take effect
6770 If there's no terminal yet (for instance, during debugger initialization),
6771 we go ahead and set C<$console> and C<$tty> to the file indicated.
6777 if ( @_ and $term and $term->Features->{newTTY} ) {
6779 # This terminal supports switching to a new TTY.
6780 # Can be a list of two files, or on string containing both names,
6782 # XXX Should this perhaps be an assignment from @_?
6783 my ( $in, $out ) = shift;
6786 # Split list apart if supplied.
6787 ( $in, $out ) = split /,/, $in, 2;
6791 # Use the same file for both input and output.
6795 # Open file onto the debugger's filehandles, if you can.
6796 open IN, $in or die "cannot open '$in' for read: $!";
6797 open OUT, ">$out" or die "cannot open '$out' for write: $!";
6799 # Swap to the new filehandles.
6800 reset_IN_OUT( \*IN, \*OUT );
6802 # Save the setting for later.
6804 } ## end if (@_ and $term and $term...
6806 # Terminal doesn't support new TTY, or doesn't support readline.
6807 # Can't do it now, try restarting.
6808 &warn("Too late to set TTY, enabled on next 'R'!\n") if $term and @_;
6810 # Useful if done through PERLDB_OPTS:
6811 $console = $tty = shift if @_;
6813 # Return whatever the TTY is.
6819 Sets the C<$notty> global, controlling whether or not the debugger tries to
6820 get a terminal to read from. If called after a terminal is already in place,
6821 we save the value to use it if we're restarted.
6827 &warn("Too late to set noTTY, enabled on next 'R'!\n") if @_;
6829 $notty = shift if @_;
6835 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
6836 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
6837 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
6838 the value in case a restart is done so we can change it then.
6844 &warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_;
6848 } ## end sub ReadLine
6850 =head2 C<RemotePort>
6852 Sets the port that the debugger will try to connect to when starting up.
6853 If the terminal's already been set up, we can't do it, but we remember the
6854 setting in case the user does a restart.
6860 &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
6862 $remoteport = shift if @_;
6864 } ## end sub RemotePort
6868 Checks with the terminal to see if C<Tk> is running, and returns true or
6869 false. Returns false if the current terminal doesn't support C<readline>.
6874 if ( ${ $term->Features }{tkRunning} ) {
6875 return $term->tkRunning(@_);
6879 print $OUT "tkRunning not supported by current ReadLine package.\n";
6882 } ## end sub tkRunning
6886 Sets nonstop mode. If a terminal's already been set up, it's too late; the
6887 debugger remembers the setting in case you restart, though.
6893 &warn("Too late to set up NonStop mode, enabled on next 'R'!\n")
6896 $runnonstop = shift if @_;
6898 } ## end sub NonStop
6902 &warn("Some flag changes could not take effect until next 'R'!\n")
6905 $^P = parse_DollarCaretP_flags(shift) if @_;
6906 expand_DollarCaretP_flags($^P);
6911 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
6919 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
6926 Sets the shell escape command, and generates a printable copy to be used
6933 # If we got an argument, meta-quote it, and add '\b' if it
6934 # ends in a word character.
6936 $sh = quotemeta shift;
6937 $sh .= "\\b" if $sh =~ /\w$/;
6940 # Generate the printable version for the help:
6941 $psh = $sh; # copy it
6942 $psh =~ s/\\b$//; # Take off trailing \b if any
6943 $psh =~ s/\\(.)/$1/g; # De-escape
6944 $psh; # return the printable version
6945 } ## end sub shellBang
6949 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
6950 was passed as the argument. (This means you can't override the terminal's
6956 if ( defined $term ) {
6958 # We don't want to show warning backtraces, but we do want die() ones.
6959 local ( $warnLevel, $dieLevel ) = ( 0, 1 );
6961 # No ornaments if the terminal doesn't support them.
6962 return '' unless $term->Features->{ornaments};
6963 eval { $term->ornaments(@_) } || '';
6966 # Use what was passed in if we can't determine it ourselves.
6970 } ## end sub ornaments
6972 =head2 C<recallCommand>
6974 Sets the recall command, and builds a printable version which will appear in
6981 # If there is input, metaquote it. Add '\b' if it ends with a word
6984 $rc = quotemeta shift;
6985 $rc .= "\\b" if $rc =~ /\w$/;
6988 # Build it into a printable version.
6989 $prc = $rc; # Copy it
6990 $prc =~ s/\\b$//; # Remove trailing \b
6991 $prc =~ s/\\(.)/$1/g; # Remove escapes
6992 $prc; # Return the printable version
6993 } ## end sub recallCommand
6995 =head2 C<LineInfo> - where the line number information goes
6997 Called with no arguments, returns the file or pipe that line info should go to.
6999 Called with an argument (a file or a pipe), it opens that onto the
7000 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7001 file or pipe again to the caller.
7006 return $lineinfo unless @_;
7009 # If this is a valid "thing to be opened for output", tack a
7010 # '>' onto the front.
7011 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7013 # If this is a pipe, the stream points to a slave editor.
7014 $slave_editor = ( $stream =~ /^\|/ );
7016 # Open it up and unbuffer it.
7017 open( LINEINFO, "$stream" ) || &warn("Cannot open '$stream' for write");
7018 $LINEINFO = \*LINEINFO;
7019 my $save = select($LINEINFO);
7023 # Hand the file or pipe back again.
7025 } ## end sub LineInfo
7027 =head1 COMMAND SUPPORT ROUTINES
7029 These subroutines provide functionality for various commands.
7031 =head2 C<list_modules>
7033 For the C<M> command: list modules loaded and their versions.
7034 Essentially just runs through the keys in %INC, picks each package's
7035 C<$VERSION> variable, gets the file name, and formats the information
7040 sub list_modules { # versions
7044 # keys are the "as-loaded" name, values are the fully-qualified path
7045 # to the file itself.
7047 $file = $_; # get the module name
7048 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7049 s,/,::,g; # change '/' to '::'
7050 s/^perl5db$/DB/; # Special case: debugger
7051 # moves to package DB
7052 s/^Term::ReadLine::readline$/readline/; # simplify readline
7054 # If the package has a $VERSION package global (as all good packages
7055 # should!) decode it and save as partial message.
7056 if ( defined ${ $_ . '::VERSION' } ) {
7057 $version{$file} = "${ $_ . '::VERSION' } from ";
7060 # Finish up the message with the file the package came from.
7061 $version{$file} .= $INC{$file};
7062 } ## end for (keys %INC)
7064 # Hey, dumpit() formats a hash nicely, so why not use it?
7065 dumpit( $OUT, \%version );
7066 } ## end sub list_modules
7070 Sets up the monster string used to format and print the help.
7072 =head3 HELP MESSAGE FORMAT
7074 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
7075 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
7076 easy to parse and portable, but which still allows the help to be a little
7077 nicer than just plain text.
7079 Essentially, you define the command name (usually marked up with C<< B<> >>
7080 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
7081 newline. The descriptive text can also be marked up in the same way. If you
7082 need to continue the descriptive text to another line, start that line with
7083 just tabs and then enter the marked-up text.
7085 If you are modifying the help text, I<be careful>. The help-string parser is
7086 not very sophisticated, and if you don't follow these rules it will mangle the
7087 help beyond hope until you fix the string.
7093 # XXX: make sure there are tabs between the command and explanation,
7094 # or print_help will screw up your formatting if you have
7095 # eeevil ornaments enabled. This is an insane mess.
7098 Help is currently only available for the new 5.8 command set.
7099 No help is available for the old command set.
7100 We assume you know what you're doing if you switch to it.
7103 B<s> [I<expr>] Single step [in I<expr>].
7104 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7105 <B<CR>> Repeat last B<n> or B<s> command.
7106 B<r> Return from current subroutine.
7107 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7108 at the specified position.
7109 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7110 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7111 B<l> I<line> List single I<line>.
7112 B<l> I<subname> List first window of lines from subroutine.
7113 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7114 B<l> List next window of lines.
7115 B<-> List previous window of lines.
7116 B<v> [I<line>] View window around I<line>.
7117 B<.> Return to the executed line.
7118 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7119 I<filename> may be either the full name of the file, or a regular
7120 expression matching the full file name:
7121 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7122 Evals (with saved bodies) are considered to be filenames:
7123 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7124 (in the order of execution).
7125 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7126 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7127 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
7128 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7129 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth).
7130 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
7131 B<b> Sets breakpoint on current line)
7132 B<b> [I<line>] [I<condition>]
7133 Set breakpoint; I<line> defaults to the current execution line;
7134 I<condition> breaks if it evaluates to true, defaults to '1'.
7135 B<b> I<subname> [I<condition>]
7136 Set breakpoint at first line of subroutine.
7137 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7138 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7139 B<b> B<postpone> I<subname> [I<condition>]
7140 Set breakpoint at first line of subroutine after
7142 B<b> B<compile> I<subname>
7143 Stop after the subroutine is compiled.
7144 B<B> [I<line>] Delete the breakpoint for I<line>.
7145 B<B> I<*> Delete all breakpoints.
7146 B<a> [I<line>] I<command>
7147 Set an action to be done before the I<line> is executed;
7148 I<line> defaults to the current execution line.
7149 Sequence is: check for breakpoint/watchpoint, print line
7150 if necessary, do action, prompt user if necessary,
7153 B<A> [I<line>] Delete the action for I<line>.
7154 B<A> I<*> Delete all actions.
7155 B<w> I<expr> Add a global watch-expression.
7157 B<W> I<expr> Delete a global watch-expression.
7158 B<W> I<*> Delete all watch-expressions.
7159 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7160 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7161 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7162 B<x> I<expr> Evals expression in list context, dumps the result.
7163 B<m> I<expr> Evals expression in list context, prints methods callable
7164 on the first element of the result.
7165 B<m> I<class> Prints methods callable via the given class.
7166 B<M> Show versions of loaded modules.
7167 B<i> I<class> Prints nested parents of given class.
7168 B<e> Display current thread id.
7169 B<E> Display all thread ids the current one will be identified: <n>.
7170 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7172 B<<> ? List Perl commands to run before each prompt.
7173 B<<> I<expr> Define Perl command to run before each prompt.
7174 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7175 B<< *> Delete the list of perl commands to run before each prompt.
7176 B<>> ? List Perl commands to run after each prompt.
7177 B<>> I<expr> Define Perl command to run after each prompt.
7178 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7179 B<>>B< *> Delete the list of Perl commands to run after each prompt.
7180 B<{> I<db_command> Define debugger command to run before each prompt.
7181 B<{> ? List debugger commands to run before each prompt.
7182 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7183 B<{ *> Delete the list of debugger commands to run before each prompt.
7184 B<$prc> I<number> Redo a previous command (default previous command).
7185 B<$prc> I<-number> Redo number'th-to-last command.
7186 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7187 See 'B<O> I<recallCommand>' too.
7188 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7193 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7195 See 'B<O> I<shellBang>' too.
7196 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7197 B<save> I<file> Save current debugger session (actual history) to I<file>.
7198 B<rerun> Rerun session to current position.
7199 B<rerun> I<n> Rerun session to numbered command.
7200 B<rerun> I<-n> Rerun session to number'th-to-last command.
7201 B<H> I<-number> Display last number commands (default all).
7202 B<H> I<*> Delete complete history.
7203 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7204 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7205 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well.
7206 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7207 I<command> Execute as a perl statement in current package.
7208 B<R> Pure-man-restart of debugger, some of debugger state
7209 and command-line options may be lost.
7210 Currently the following settings are preserved:
7211 history, breakpoints and actions, debugger B<O>ptions
7212 and the following command-line options: I<-w>, I<-I>, I<-e>.
7214 B<o> [I<opt>] ... Set boolean option to true
7215 B<o> [I<opt>B<?>] Query options
7216 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7217 Set options. Use quotes if spaces in value.
7218 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7219 I<pager> program for output of \"|cmd\";
7220 I<tkRunning> run Tk while prompting (with ReadLine);
7221 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7222 I<inhibit_exit> Allows stepping off the end of the script.
7223 I<ImmediateStop> Debugger should stop as early as possible.
7224 I<RemotePort> Remote hostname:port for remote debugging
7225 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7226 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7227 I<compactDump>, I<veryCompact> change style of array and hash dump;
7228 I<globPrint> whether to print contents of globs;
7229 I<DumpDBFiles> dump arrays holding debugged files;
7230 I<DumpPackages> dump symbol tables of packages;
7231 I<DumpReused> dump contents of \"reused\" addresses;
7232 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7233 I<bareStringify> Do not print the overload-stringified value;
7234 Other options include:
7235 I<PrintRet> affects printing of return value after B<r> command,
7236 I<frame> affects printing messages on subroutine entry/exit.
7237 I<AutoTrace> affects printing messages on possible breaking points.
7238 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7239 I<ornaments> affects screen appearance of the command line.
7240 I<CreateTTY> bits control attempts to create a new TTY on events:
7241 1: on fork() 2: debugger is started inside debugger
7243 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7244 You can put additional initialization options I<TTY>, I<noTTY>,
7245 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7246 B<R> after you set them).
7248 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7249 B<h> Summary of debugger commands.
7250 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7251 B<h h> Long help for debugger commands
7252 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7253 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7254 Set B<\$DB::doccmd> to change viewer.
7256 Type '|h h' for a paged display if this was too hard to read.
7258 "; # Fix balance of vi % matching: }}}}
7260 # note: tabs in the following section are not-so-helpful
7261 $summary = <<"END_SUM";
7262 I<List/search source lines:> I<Control script execution:>
7263 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7264 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7265 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7266 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7267 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7268 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7269 I<Debugger controls:> B<L> List break/watch/actions
7270 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr]
7271 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7272 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7273 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7274 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7275 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7276 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7277 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7278 B<q> or B<^D> Quit B<R> Attempt a restart
7279 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7280 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7281 B<p> I<expr> Print expression (uses script's current package).
7282 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7283 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7284 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
7285 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7286 B<e> Display thread id B<E> Display all thread ids.
7287 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7290 # ')}}; # Fix balance of vi % matching
7292 # and this is really numb...
7295 B<s> [I<expr>] Single step [in I<expr>].
7296 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7297 B<CR>> Repeat last B<n> or B<s> command.
7298 B<r> Return from current subroutine.
7299 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7300 at the specified position.
7301 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7302 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7303 B<l> I<line> List single I<line>.
7304 B<l> I<subname> List first window of lines from subroutine.
7305 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7306 B<l> List next window of lines.
7307 B<-> List previous window of lines.
7308 B<w> [I<line>] List window around I<line>.
7309 B<.> Return to the executed line.
7310 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7311 I<filename> may be either the full name of the file, or a regular
7312 expression matching the full file name:
7313 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7314 Evals (with saved bodies) are considered to be filenames:
7315 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7316 (in the order of execution).
7317 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7318 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7319 B<L> List all breakpoints and actions.
7320 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7321 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) .
7322 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
7323 B<b> [I<line>] [I<condition>]
7324 Set breakpoint; I<line> defaults to the current execution line;
7325 I<condition> breaks if it evaluates to true, defaults to '1'.
7326 B<b> I<subname> [I<condition>]
7327 Set breakpoint at first line of subroutine.
7328 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7329 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7330 B<b> B<postpone> I<subname> [I<condition>]
7331 Set breakpoint at first line of subroutine after
7333 B<b> B<compile> I<subname>
7334 Stop after the subroutine is compiled.
7335 B<d> [I<line>] Delete the breakpoint for I<line>.
7336 B<D> Delete all breakpoints.
7337 B<a> [I<line>] I<command>
7338 Set an action to be done before the I<line> is executed;
7339 I<line> defaults to the current execution line.
7340 Sequence is: check for breakpoint/watchpoint, print line
7341 if necessary, do action, prompt user if necessary,
7343 B<a> [I<line>] Delete the action for I<line>.
7344 B<A> Delete all actions.
7345 B<W> I<expr> Add a global watch-expression.
7346 B<W> Delete all watch-expressions.
7347 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7348 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7349 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7350 B<x> I<expr> Evals expression in list context, dumps the result.
7351 B<m> I<expr> Evals expression in list context, prints methods callable
7352 on the first element of the result.
7353 B<m> I<class> Prints methods callable via the given class.
7355 B<<> ? List Perl commands to run before each prompt.
7356 B<<> I<expr> Define Perl command to run before each prompt.
7357 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7358 B<>> ? List Perl commands to run after each prompt.
7359 B<>> I<expr> Define Perl command to run after each prompt.
7360 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7361 B<{> I<db_command> Define debugger command to run before each prompt.
7362 B<{> ? List debugger commands to run before each prompt.
7363 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7364 B<$prc> I<number> Redo a previous command (default previous command).
7365 B<$prc> I<-number> Redo number'th-to-last command.
7366 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7367 See 'B<O> I<recallCommand>' too.
7368 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7373 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7375 See 'B<O> I<shellBang>' too.
7376 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7377 B<H> I<-number> Display last number commands (default all).
7378 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7379 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7380 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7381 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7382 I<command> Execute as a perl statement in current package.
7383 B<v> Show versions of loaded modules.
7384 B<R> Pure-man-restart of debugger, some of debugger state
7385 and command-line options may be lost.
7386 Currently the following settings are preserved:
7387 history, breakpoints and actions, debugger B<O>ptions
7388 and the following command-line options: I<-w>, I<-I>, I<-e>.
7390 B<O> [I<opt>] ... Set boolean option to true
7391 B<O> [I<opt>B<?>] Query options
7392 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7393 Set options. Use quotes if spaces in value.
7394 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7395 I<pager> program for output of \"|cmd\";
7396 I<tkRunning> run Tk while prompting (with ReadLine);
7397 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7398 I<inhibit_exit> Allows stepping off the end of the script.
7399 I<ImmediateStop> Debugger should stop as early as possible.
7400 I<RemotePort> Remote hostname:port for remote debugging
7401 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7402 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7403 I<compactDump>, I<veryCompact> change style of array and hash dump;
7404 I<globPrint> whether to print contents of globs;
7405 I<DumpDBFiles> dump arrays holding debugged files;
7406 I<DumpPackages> dump symbol tables of packages;
7407 I<DumpReused> dump contents of \"reused\" addresses;
7408 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7409 I<bareStringify> Do not print the overload-stringified value;
7410 Other options include:
7411 I<PrintRet> affects printing of return value after B<r> command,
7412 I<frame> affects printing messages on subroutine entry/exit.
7413 I<AutoTrace> affects printing messages on possible breaking points.
7414 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7415 I<ornaments> affects screen appearance of the command line.
7416 I<CreateTTY> bits control attempts to create a new TTY on events:
7417 1: on fork() 2: debugger is started inside debugger
7419 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7420 You can put additional initialization options I<TTY>, I<noTTY>,
7421 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7422 B<R> after you set them).
7424 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7425 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7426 B<h h> Summary of debugger commands.
7427 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7428 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7429 Set B<\$DB::doccmd> to change viewer.
7431 Type '|h' for a paged display if this was too hard to read.
7433 "; # Fix balance of vi % matching: }}}}
7435 # note: tabs in the following section are not-so-helpful
7436 $pre580_summary = <<"END_SUM";
7437 I<List/search source lines:> I<Control script execution:>
7438 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7439 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7440 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
7441 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7442 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7443 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
7444 I<Debugger controls:> B<L> List break/watch/actions
7445 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7446 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7447 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
7448 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7449 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
7450 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
7451 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7452 B<q> or B<^D> Quit B<R> Attempt a restart
7453 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7454 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7455 B<p> I<expr> Print expression (uses script's current package).
7456 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7457 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7458 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
7459 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7460 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7463 # ')}}; # Fix balance of vi % matching
7465 } ## end sub sethelp
7467 =head2 C<print_help()>
7469 Most of what C<print_help> does is just text formatting. It finds the
7470 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
7471 terminal control characters to simulate them (courtesy of
7472 C<Term::ReadLine::TermCap>).
7479 # Restore proper alignment destroyed by eeevil I<> and B<>
7480 # ornaments: A pox on both their houses!
7482 # A help command will have everything up to and including
7483 # the first tab sequence padded into a field 16 (or if indented 20)
7484 # wide. If it's wider than that, an extra space will be added.
7486 ^ # only matters at start of line
7487 ( \040{4} | \t )* # some subcommands are indented
7488 ( < ? # so <CR> works
7489 [BI] < [^\t\n] + ) # find an eeevil ornament
7490 ( \t+ ) # original separation, discarded
7491 ( .* ) # this will now start (no earlier) than
7494 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
7495 my $clean = $command;
7496 $clean =~ s/[BI]<([^>]*)>/$1/g;
7498 # replace with this whole string:
7499 ($leadwhite ? " " x 4 : "")
7501 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
7506 s{ # handle bold ornaments
7507 B < ( [^>] + | > ) >
7509 $Term::ReadLine::TermCap::rl_term_set[2]
7511 . $Term::ReadLine::TermCap::rl_term_set[3]
7514 s{ # handle italic ornaments
7515 I < ( [^>] + | > ) >
7517 $Term::ReadLine::TermCap::rl_term_set[0]
7519 . $Term::ReadLine::TermCap::rl_term_set[1]
7524 } ## end sub print_help
7528 This routine does a lot of gyrations to be sure that the pager is C<less>.
7529 It checks for C<less> masquerading as C<more> and records the result in
7530 C<$fixed_less> so we don't have to go through doing the stats again.
7536 # We already know if this is set.
7537 return if $fixed_less;
7539 # Pager is less for sure.
7540 my $is_less = $pager =~ /\bless\b/;
7541 if ( $pager =~ /\bmore\b/ ) {
7543 # Nope, set to more. See what's out there.
7544 my @st_more = stat('/usr/bin/more');
7545 my @st_less = stat('/usr/bin/less');
7547 # is it really less, pretending to be more?
7550 && $st_more[0] == $st_less[0]
7551 && $st_more[1] == $st_less[1];
7552 } ## end if ($pager =~ /\bmore\b/)
7554 # changes environment!
7555 # 'r' added so we don't do (slow) stats again.
7556 $fixed_less = 1 if $is_less;
7557 } ## end sub fix_less
7559 =head1 DIE AND WARN MANAGEMENT
7563 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
7564 to debug a debugger problem.
7566 It does its best to report the error that occurred, and then forces the
7567 program, debugger, and everything to die.
7573 # No entry/exit messages.
7576 # No return value prints.
7579 # set the abort signal handling to the default (just terminate).
7580 $SIG{'ABRT'} = 'DEFAULT';
7582 # If we enter the signal handler recursively, kill myself with an
7583 # abort signal (so we just terminate).
7584 kill 'ABRT', $$ if $panic++;
7586 # If we can show detailed info, do so.
7587 if ( defined &Carp::longmess ) {
7589 # Don't recursively enter the warn handler, since we're carping.
7590 local $SIG{__WARN__} = '';
7592 # Skip two levels before reporting traceback: we're skipping
7593 # mydie and confess.
7594 local $Carp::CarpLevel = 2; # mydie + confess
7596 # Tell us all about it.
7597 &warn( Carp::longmess("Signal @_") );
7600 # No Carp. Tell us about the signal as best we can.
7603 print $DB::OUT "Got signal @_\n";
7608 } ## end sub diesignal
7612 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
7613 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
7619 # No entry/exit trace.
7622 # No return value printing.
7625 # Turn off warn and die handling to prevent recursive entries to this
7627 local $SIG{__WARN__} = '';
7628 local $SIG{__DIE__} = '';
7630 # Load Carp if we can. If $^S is false (current thing being compiled isn't
7631 # done yet), we may not be able to do a require.
7632 eval { require Carp }
7633 if defined $^S; # If error/warning during compilation,
7634 # require may be broken.
7636 # Use the core warn() unless Carp loaded OK.
7638 "\nCannot print stack trace, load with -MCarp option to see stack" ),
7640 unless defined &Carp::longmess;
7642 # Save the current values of $single and $trace, and then turn them off.
7643 my ( $mysingle, $mytrace ) = ( $single, $trace );
7647 # We can call Carp::longmess without its being "debugged" (which we
7648 # don't want - we just want to use it!). Capture this for later.
7649 my $mess = Carp::longmess(@_);
7651 # Restore $single and $trace to their original values.
7652 ( $single, $trace ) = ( $mysingle, $mytrace );
7654 # Use the debugger's own special way of printing warnings to print
7655 # the stack trace message.
7661 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
7662 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
7663 single stepping and tracing during the call to C<Carp::longmess> to avoid
7664 debugging it - we just want to use it.
7666 If C<dieLevel> is zero, we let the program being debugged handle the
7667 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
7668 the debugger takes over all exception handling, printing a backtrace and
7669 displaying the exception via its C<dbwarn()> routine.
7676 local $SIG{__DIE__} = '';
7677 local $SIG{__WARN__} = '';
7681 if ( $dieLevel > 2 ) {
7682 local $SIG{__WARN__} = \&dbwarn;
7683 &warn(@_); # Yell no matter what
7686 if ( $dieLevel < 2 ) {
7687 die @_ if $^S; # in eval propagate
7690 # The code used to check $^S to see if compilation of the current thing
7691 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
7692 eval { require Carp };
7695 "\nCannot print stack trace, load with -MCarp option to see stack" )
7696 unless defined &Carp::longmess;
7698 # We do not want to debug this chunk (automatic disabling works
7699 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
7700 # get the stack trace from Carp::longmess (if possible), restore $signal
7701 # and $trace, and then die with the stack trace.
7702 my ( $mysingle, $mytrace ) = ( $single, $trace );
7708 package Carp; # Do not include us in the list
7709 eval { $mess = Carp::longmess(@_); };
7711 ( $single, $trace ) = ( $mysingle, $mytrace );
7715 =head2 C<warnlevel()>
7717 Set the C<$DB::warnLevel> variable that stores the value of the
7718 C<warnLevel> option. Calling C<warnLevel()> with a positive value
7719 results in the debugger taking over all warning handlers. Setting
7720 C<warnLevel> to zero leaves any warning handlers set up by the program
7721 being debugged in place.
7727 $prevwarn = $SIG{__WARN__} unless $warnLevel;
7730 $SIG{__WARN__} = \&DB::dbwarn;
7733 $SIG{__WARN__} = $prevwarn;
7735 undef $SIG{__WARN__};
7739 } ## end sub warnLevel
7743 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
7744 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
7745 zero lets you use your own C<die()> handler.
7752 $prevdie = $SIG{__DIE__} unless $dieLevel;
7756 # Always set it to dbdie() for non-zero values.
7757 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
7759 # No longer exists, so don't try to use it.
7760 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
7762 # If we've finished initialization, mention that stack dumps
7763 # are enabled, If dieLevel is 1, we won't stack dump if we die
7765 print $OUT "Stack dump during die enabled",
7766 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
7769 # XXX This is probably obsolete, given that diehard() is gone.
7770 print $OUT "Dump printed too.\n" if $dieLevel > 2;
7771 } ## end if ($dieLevel)
7773 # Put the old one back if there was one.
7775 $SIG{__DIE__} = $prevdie;
7776 print $OUT "Default die handler restored.\n";
7778 undef $SIG{__DIE__};
7779 print $OUT "Die handler removed.\n";
7783 } ## end sub dieLevel
7785 =head2 C<signalLevel>
7787 Number three in a series: set C<signalLevel> to zero to keep your own
7788 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
7789 takes over and handles them with C<DB::diesignal()>.
7795 $prevsegv = $SIG{SEGV} unless $signalLevel;
7796 $prevbus = $SIG{BUS} unless $signalLevel;
7797 $signalLevel = shift;
7799 $SIG{SEGV} = \&DB::diesignal;
7800 $SIG{BUS} = \&DB::diesignal;
7803 $SIG{SEGV} = $prevsegv;
7804 $SIG{BUS} = $prevbus;
7808 } ## end sub signalLevel
7810 =head1 SUBROUTINE DECODING SUPPORT
7812 These subroutines are used during the C<x> and C<X> commands to try to
7813 produce as much information as possible about a code reference. They use
7814 L<Devel::Peek> to try to find the glob in which this code reference lives
7815 (if it does) - this allows us to actually code references which correspond
7816 to named subroutines (including those aliased via glob assignment).
7818 =head2 C<CvGV_name()>
7820 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
7821 via that routine. If this fails, return the reference again (when the
7822 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
7828 my $name = CvGV_name_or_bust($in);
7829 defined $name ? $name : $in;
7832 =head2 C<CvGV_name_or_bust> I<coderef>
7834 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
7835 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
7836 find a glob for this ref.
7838 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
7842 sub CvGV_name_or_bust {
7844 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
7845 return unless ref $in;
7846 $in = \&$in; # Hard reference...
7847 eval { require Devel::Peek; 1 } or return;
7848 my $gv = Devel::Peek::CvGV($in) or return;
7849 *$gv{PACKAGE} . '::' . *$gv{NAME};
7850 } ## end sub CvGV_name_or_bust
7854 A utility routine used in various places; finds the file where a subroutine
7855 was defined, and returns that filename and a line-number range.
7857 Tries to use C<@sub> first; if it can't find it there, it tries building a
7858 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
7859 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
7860 this way, it brute-force searches C<%sub>, checking for identical references.
7867 return unless defined &$subr;
7868 my $name = CvGV_name_or_bust($subr);
7870 $data = $sub{$name} if defined $name;
7871 return $data if defined $data;
7874 $subr = \&$subr; # Hard reference
7877 $s = $_, last if $subr eq \&$_;
7881 } ## end sub find_sub
7885 A subroutine that uses the utility function C<methods_via> to find all the
7886 methods in the class corresponding to the current reference and in
7893 # Figure out the class - either this is the class or it's a reference
7894 # to something blessed into that class.
7896 $class = ref $class if ref $class;
7900 # Show the methods that this class has.
7901 methods_via( $class, '', 1 );
7903 # Show the methods that UNIVERSAL has.
7904 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
7905 } ## end sub methods
7907 =head2 C<methods_via($class, $prefix, $crawl_upward)>
7909 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
7910 all the parent class methods. C<$class> is the name of the next class to
7911 try; C<$prefix> is the message prefix, which gets built up as we go up the
7912 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
7913 higher in the C<@ISA> tree, 0 if we should stop.
7919 # If we've processed this class already, just quit.
7921 return if $seen{$class}++;
7923 # This is a package that is contributing the methods we're about to print.
7925 my $prepend = $prefix ? "via $prefix: " : '';
7928 # Extract from all the symbols in this class.
7929 while (my ($name, $glob) = each %{"${class}::"}) {
7930 # references directly in the symbol table are Proxy Constant
7931 # Subroutines, and are by their very nature defined
7932 # Otherwise, check if the thing is a typeglob, and if it is, it decays
7933 # to a subroutine reference, which can be tested by defined.
7934 # $glob might also be the value -1 (from sub foo;)
7935 # or (say) '$$' (from sub foo ($$);)
7936 # \$glob will be SCALAR in both cases.
7937 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
7938 && !$seen{$name}++) {
7939 push @to_print, "$prepend$name\n";
7946 print $DB::OUT $_ foreach sort @to_print;
7949 # If the $crawl_upward argument is false, just quit here.
7950 return unless shift;
7952 # $crawl_upward true: keep going up the tree.
7953 # Find all the classes this one is a subclass of.
7954 for $name ( @{"${class}::ISA"} ) {
7956 # Set up the new prefix.
7957 $prepend = $prefix ? $prefix . " -> $name" : $name;
7959 # Crawl up the tree and keep trying to crawl up.
7960 methods_via( $name, $prepend, 1 );
7962 } ## end sub methods_via
7964 =head2 C<setman> - figure out which command to use to show documentation
7966 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
7971 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|NetWare)\z/s
7972 ? "man" # O Happy Day!
7973 : "perldoc"; # Alas, poor unfortunates
7976 =head2 C<runman> - run the appropriate command to show documentation
7978 Accepts a man page name; runs the appropriate command to display it (set up
7979 during debugger initialization). Uses C<DB::system> to avoid mucking up the
7980 program's STDIN and STDOUT.
7987 &system("$doccmd $doccmd");
7991 # this way user can override, like with $doccmd="man -Mwhatever"
7992 # or even just "man " to disable the path check.
7993 unless ( $doccmd eq 'man' ) {
7994 &system("$doccmd $page");
7998 $page = 'perl' if lc($page) eq 'help';
8001 my $man1dir = $Config::Config{'man1dir'};
8002 my $man3dir = $Config::Config{'man3dir'};
8003 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8005 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8006 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8007 chop $manpath if $manpath;
8009 # harmless if missing, I figure
8010 my $oldpath = $ENV{MANPATH};
8011 $ENV{MANPATH} = $manpath if $manpath;
8012 my $nopathopt = $^O =~ /dunno what goes here/;
8017 # I just *know* there are men without -M
8018 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8023 unless ( $page =~ /^perl\w/ ) {
8024 # 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)
8541 If it's C<main>, delete main to just get C<::> leading.
8545 $pack = ( $package eq 'main' ? '' : $package ) . '::';
8551 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
8555 $prefix = substr $text, 0, 1;
8556 $text = substr $text, 1;
8564 We look for the lexical scope above DB::DB and auto-complete lexical variables
8565 if PadWalker could be loaded.
8569 if (not $text =~ /::/ and eval { require PadWalker } ) {
8572 my @info = caller($level);
8576 last if $info[3] eq 'DB::DB';
8579 my $lexicals = PadWalker::peek_my($level);
8580 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
8588 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
8592 push @out, map "$prefix$_", grep /^\Q$text/,
8593 ( grep /^_?[a-zA-Z]/, keys %$pack ),
8594 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
8598 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
8604 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8605 return db_complete( $out[0], $line, $start );
8608 # Return the list of possibles.
8610 } ## end if ($text =~ /^[\$@%]/)
8614 We use C<option_val()> to look up the current value of the option. If there's
8615 only a single value, we complete the command in such a way that it is a
8616 complete command for setting the option in question. If there are multiple
8617 possible values, we generate a command consisting of the option plus a trailing
8618 question mark, which, if executed, will list the current value of the option.
8622 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
8623 { # Options after space
8624 # We look for the text to be matched in the list of possible options,
8625 # and fetch the current value.
8626 my @out = grep /^\Q$text/, @options;
8627 my $val = option_val( $out[0], undef );
8629 # Set up a 'query option's value' command.
8631 if ( not defined $val or $val =~ /[\n\r]/ ) {
8633 # There's really nothing else we can do.
8636 # We have a value. Create a proper option-setting command.
8637 elsif ( $val =~ /\s/ ) {
8639 # XXX This may be an extraneous variable.
8642 # We'll want to quote the string (because of the embedded
8643 # whtespace), but we want to make sure we don't end up with
8644 # mismatched quote characters. We try several possibilities.
8645 foreach $l ( split //, qq/\"\'\#\|/ ) {
8647 # If we didn't find this quote character in the value,
8648 # quote it using this quote character.
8649 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
8651 } ## end elsif ($val =~ /\s/)
8653 # Don't need any quotes.
8658 # If there were multiple possible values, return '? ', which
8659 # makes the command into a query command. If there was just one,
8660 # have readline append that.
8661 $rl_attribs->{completer_terminator_character} =
8662 ( @out == 1 ? $out : '? ' );
8664 # Return list of possibilities.
8666 } ## end if ((substr $line, 0, ...
8668 =head3 Filename completion
8670 For entering filenames. We simply call C<readline>'s C<filename_list()>
8671 method with the completion text to get the possible completions.
8675 return $term->filename_list($text); # filenames
8677 } ## end sub db_complete
8679 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
8681 Functions that possibly ought to be somewhere else.
8691 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n";
8696 If we have $ini_pids, save it in the environment; else remove it from the
8697 environment. Used by the C<R> (restart) command.
8702 if ( defined($ini_pids) ) {
8703 $ENV{PERLDB_PIDS} = $ini_pids;
8706 delete( $ENV{PERLDB_PIDS} );
8708 } ## end sub clean_ENV
8710 # PERLDBf_... flag names from perl.h
8711 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
8714 %DollarCaretP_flags = (
8715 PERLDBf_SUB => 0x01, # Debug sub enter/exit
8716 PERLDBf_LINE => 0x02, # Keep line #
8717 PERLDBf_NOOPT => 0x04, # Switch off optimizations
8718 PERLDBf_INTER => 0x08, # Preserve more data
8719 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
8720 PERLDBf_SINGLE => 0x20, # Start with single-step on
8721 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
8722 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
8723 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
8724 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
8725 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
8726 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
8728 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
8729 # doesn't need to set it. It's provided for the benefit of profilers and
8730 # other code analysers.
8732 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
8735 sub parse_DollarCaretP_flags {
8740 foreach my $f ( split /\s*\|\s*/, $flags ) {
8742 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
8745 elsif ( $f =~ /^(\d+)$/ ) {
8748 elsif ( $f =~ /^DEFAULT$/i ) {
8749 $value = $DollarCaretP_flags{PERLDB_ALL};
8752 $f =~ /^(?:PERLDBf_)?(.*)$/i;
8753 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
8754 unless ( defined $value ) {
8756 "Unrecognized \$^P flag '$f'!\n",
8757 "Acceptable flags are: "
8758 . join( ', ', sort keys %DollarCaretP_flags ),
8759 ", and hexadecimal and decimal numbers.\n"
8769 sub expand_DollarCaretP_flags {
8770 my $DollarCaretP = shift;
8773 my $n = ( 1 << $_ );
8774 ( $DollarCaretP & $n )
8775 ? ( $DollarCaretP_flags_r{$n}
8776 || sprintf( '0x%x', $n ) )
8780 return @bits ? join( '|', @bits ) : 0;
8787 Rerun the current session to:
8789 rerun current position
8791 rerun 4 command number 4
8793 rerun -4 current command minus 4 (go back 4 steps)
8795 Whether this always makes sense, in the current context is unknowable, and is
8796 in part left as a useful exercise for the reader. This sub returns the
8797 appropriate arguments to rerun the current session.
8804 pop(@truehist); # strim
8805 unless (defined $truehist[$i]) {
8806 print "Unable to return to non-existent command: $i\n";
8808 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
8809 my @temp = @truehist; # store
8810 push(@DB::typeahead, @truehist); # saved
8811 @truehist = @hist = (); # flush
8812 @args = &restart(); # setup
8813 &get_list("PERLDB_HIST"); # clean
8814 &set_list("PERLDB_HIST", @temp); # reset
8821 Restarting the debugger is a complex operation that occurs in several phases.
8822 First, we try to reconstruct the command line that was used to invoke Perl
8828 # I may not be able to resurrect you, but here goes ...
8830 "Warning: some settings and command-line options may be lost!\n";
8831 my ( @script, @flags, $cl );
8833 # If warn was on before, turn it on again.
8834 push @flags, '-w' if $ini_warn;
8836 # Rebuild the -I flags that were on the initial
8839 push @flags, '-I', $_;
8842 # Turn on taint if it was on before.
8843 push @flags, '-T' if ${^TAINT};
8845 # Arrange for setting the old INC:
8846 # Save the current @init_INC in the environment.
8847 set_list( "PERLDB_INC", @ini_INC );
8849 # If this was a perl one-liner, go to the "file"
8850 # corresponding to the one-liner read all the lines
8851 # out of it (except for the first one, which is going
8852 # to be added back on again when 'perl -d' runs: that's
8853 # the 'require perl5db.pl;' line), and add them back on
8854 # to the command line to be executed.
8856 for ( 1 .. $#{'::_<-e'} ) { # The first line is PERL5DB
8857 chomp( $cl = ${'::_<-e'}[$_] );
8858 push @script, '-e', $cl;
8860 } ## end if ($0 eq '-e')
8862 # Otherwise we just reuse the original name we had
8870 After the command line has been reconstructed, the next step is to save
8871 the debugger's status in environment variables. The C<DB::set_list> routine
8872 is used to save aggregate variables (both hashes and arrays); scalars are
8873 just popped into environment variables directly.
8877 # If the terminal supported history, grab it and
8878 # save that in the environment.
8879 set_list( "PERLDB_HIST",
8880 $term->Features->{getHistory}
8884 # Find all the files that were visited during this
8885 # session (i.e., the debugger had magic hashes
8886 # corresponding to them) and stick them in the environment.
8887 my @had_breakpoints = keys %had_breakpoints;
8888 set_list( "PERLDB_VISITED", @had_breakpoints );
8890 # Save the debugger options we chose.
8891 set_list( "PERLDB_OPT", %option );
8892 # set_list( "PERLDB_OPT", options2remember() );
8894 # Save the break-on-loads.
8895 set_list( "PERLDB_ON_LOAD", %break_on_load );
8899 The most complex part of this is the saving of all of the breakpoints. They
8900 can live in an awful lot of places, and we have to go through all of them,
8901 find the breakpoints, and then save them in the appropriate environment
8902 variable via C<DB::set_list>.
8906 # Go through all the breakpoints and make sure they're
8909 for ( 0 .. $#had_breakpoints ) {
8911 # We were in this file.
8912 my $file = $had_breakpoints[$_];
8914 # Grab that file's magic line hash.
8915 *dbline = $main::{ '_<' . $file };
8917 # Skip out if it doesn't exist, or if the breakpoint
8918 # is in a postponed file (we'll do postponed ones
8920 next unless %dbline or $postponed_file{$file};
8922 # In an eval. This is a little harder, so we'll
8923 # do more processing on that below.
8924 ( push @hard, $file ), next
8925 if $file =~ /^\(\w*eval/;
8927 # XXX I have no idea what this is doing. Yet.
8929 @add = %{ $postponed_file{$file} }
8930 if $postponed_file{$file};
8932 # Save the list of all the breakpoints for this file.
8933 set_list( "PERLDB_FILE_$_", %dbline, @add );
8935 # Serialize the extra data %breakpoints_data hash.
8937 set_list( "PERLDB_FILE_ENABLED_$_",
8938 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 }
8939 sort { $a <=> $b } keys(%dbline)
8941 } ## end for (0 .. $#had_breakpoints)
8943 # The breakpoint was inside an eval. This is a little
8944 # more difficult. XXX and I don't understand it.
8946 # Get over to the eval in question.
8947 *dbline = $main::{ '_<' . $_ };
8948 my ( $quoted, $sub, %subs, $line ) = quotemeta $_;
8949 for $sub ( keys %sub ) {
8950 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
8951 $subs{$sub} = [ $1, $2 ];
8955 "No subroutines in $_, ignoring breakpoints.\n";
8958 LINES: for $line ( keys %dbline ) {
8960 # One breakpoint per sub only:
8961 my ( $offset, $sub, $found );
8962 SUBS: for $sub ( keys %subs ) {
8965 $line # Not after the subroutine
8967 not defined $offset # Not caught
8973 $offset = $line - $subs{$sub}->[0];
8974 $offset = "+$offset", last SUBS
8976 } ## end if ($subs{$sub}->[1] >=...
8977 } ## end for $sub (keys %subs)
8978 if ( defined $offset ) {
8979 $postponed{$found} =
8980 "break $offset if $dbline{$line}";
8984 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
8986 } ## end for $line (keys %dbline)
8987 } ## end for (@hard)
8989 # Save the other things that don't need to be
8991 set_list( "PERLDB_POSTPONE", %postponed );
8992 set_list( "PERLDB_PRETYPE", @$pretype );
8993 set_list( "PERLDB_PRE", @$pre );
8994 set_list( "PERLDB_POST", @$post );
8995 set_list( "PERLDB_TYPEAHEAD", @typeahead );
8997 # We are officially restarting.
8998 $ENV{PERLDB_RESTART} = 1;
9000 # We are junking all child debuggers.
9001 delete $ENV{PERLDB_PIDS}; # Restore ini state
9003 # Set this back to the initial pid.
9004 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9008 After all the debugger status has been saved, we take the command we built up
9009 and then return it, so we can C<exec()> it. The debugger will spot the
9010 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9011 from the environment.
9015 # And run Perl again. Add the "-d" flag, all the
9016 # flags we built up, the script (whether a one-liner
9017 # or a file), add on the -emacs flag for a slave editor,
9018 # and then the old arguments.
9020 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9026 =head1 END PROCESSING - THE C<END> BLOCK
9028 Come here at the very end of processing. We want to go into a
9029 loop where we allow the user to enter commands and interact with the
9030 debugger, but we don't want anything else to execute.
9032 First we set the C<$finished> variable, so that some commands that
9033 shouldn't be run after the end of program quit working.
9035 We then figure out whether we're truly done (as in the user entered a C<q>
9036 command, or we finished execution while running nonstop). If we aren't,
9037 we set C<$single> to 1 (causing the debugger to get control again).
9039 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9040 message and returns control to the debugger. Repeat.
9042 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9043 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9044 break, run to completion.).
9049 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9050 $fall_off_end = 1 unless $inhibit_exit;
9052 # Do not stop in at_exit() and destructors on exit:
9053 if ($fall_off_end or $runnonstop) {
9057 DB::fake::at_exit();
9061 =head1 PRE-5.8 COMMANDS
9063 Some of the commands changed function quite a bit in the 5.8 command
9064 realignment, so much so that the old code had to be replaced completely.
9065 Because we wanted to retain the option of being able to go back to the
9066 former command set, we moved the old code off to this section.
9068 There's an awful lot of duplicated code here. We've duplicated the
9069 comments to keep things clear.
9073 Does nothing. Used to I<turn off> commands.
9077 sub cmd_pre580_null {
9082 =head2 Old C<a> command.
9084 This version added actions if you supplied them, and deleted them
9093 # Argument supplied. Add the action.
9094 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9096 # If the line isn't there, use the current line.
9100 # If there is an action ...
9103 # ... but the line isn't breakable, skip it.
9104 if ( $dbline[$i] == 0 ) {
9105 print $OUT "Line $i may not have an action.\n";
9109 # ... and the line is breakable:
9110 # Mark that there's an action in this file.
9111 $had_breakpoints{$filename} |= 2;
9113 # Delete any current action.
9114 $dbline{$i} =~ s/\0[^\0]*//;
9116 # Add the new action, continuing the line as needed.
9117 $dbline{$i} .= "\0" . action($j);
9119 } ## end if (length $j)
9121 # No action supplied.
9124 # Delete the action.
9125 $dbline{$i} =~ s/\0[^\0]*//;
9127 # Mark as having no break or action if nothing's left.
9128 delete $dbline{$i} if $dbline{$i} eq '';
9130 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9131 } ## end sub cmd_pre580_a
9133 =head2 Old C<b> command
9145 if ( $cmd =~ /^load\b\s*(.*)/ ) {
9151 # b compile|postpone <some sub> [<condition>]
9152 # The interpreter actually traps this one for us; we just put the
9153 # necessary condition in the %postponed hash.
9154 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
9156 # Capture the condition if there is one. Make it true if none.
9157 my $cond = length $3 ? $3 : '1';
9159 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
9160 # if it was 'compile'.
9161 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
9163 # De-Perl4-ify the name - ' separators to ::.
9164 $subname =~ s/\'/::/g;
9166 # Qualify it into the current package unless it's already qualified.
9167 $subname = "${'package'}::" . $subname
9168 unless $subname =~ /::/;
9170 # Add main if it starts with ::.
9171 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
9173 # Save the break type for this sub.
9174 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
9175 } ## end elsif ($cmd =~ ...
9177 # b <sub name> [<condition>]
9178 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
9180 my $cond = length $2 ? $2 : '1';
9181 &cmd_b_sub( $subname, $cond );
9183 # b <line> [<condition>].
9184 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9185 my $i = $1 || $dbline;
9186 my $cond = length $2 ? $2 : '1';
9187 &cmd_b_line( $i, $cond );
9189 } ## end sub cmd_pre580_b
9191 =head2 Old C<D> command.
9193 Delete all breakpoints unconditionally.
9200 if ( $cmd =~ /^\s*$/ ) {
9201 print $OUT "Deleting all breakpoints...\n";
9203 # %had_breakpoints lists every file that had at least one
9206 for $file ( keys %had_breakpoints ) {
9208 # Switch to the desired file temporarily.
9209 local *dbline = $main::{ '_<' . $file };
9214 # For all lines in this file ...
9215 for ( $i = 1 ; $i <= $max ; $i++ ) {
9217 # If there's a breakpoint or action on this line ...
9218 if ( defined $dbline{$i} ) {
9220 # ... remove the breakpoint.
9221 $dbline{$i} =~ s/^[^\0]+//;
9222 if ( $dbline{$i} =~ s/^\0?$// ) {
9224 # Remove the entry altogether if no action is there.
9227 } ## end if (defined $dbline{$i...
9228 } ## end for ($i = 1 ; $i <= $max...
9230 # If, after we turn off the "there were breakpoints in this file"
9231 # bit, the entry in %had_breakpoints for this file is zero,
9232 # we should remove this file from the hash.
9233 if ( not $had_breakpoints{$file} &= ~1 ) {
9234 delete $had_breakpoints{$file};
9236 } ## end for $file (keys %had_breakpoints)
9238 # Kill off all the other breakpoints that are waiting for files that
9239 # haven't been loaded yet.
9241 undef %postponed_file;
9242 undef %break_on_load;
9243 } ## end if ($cmd =~ /^\s*$/)
9244 } ## end sub cmd_pre580_D
9246 =head2 Old C<h> command
9248 Print help. Defaults to printing the long-form help; the 5.8 version
9249 prints the summary by default.
9257 # Print the *right* help, long format.
9258 if ( $cmd =~ /^\s*$/ ) {
9259 print_help($pre580_help);
9262 # 'h h' - explicitly-requested summary.
9263 elsif ( $cmd =~ /^h\s*/ ) {
9264 print_help($pre580_summary);
9267 # Find and print a command's help.
9268 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
9269 my $asked = $1; # for proper errmsg
9270 my $qasked = quotemeta($asked); # for searching
9271 # XXX: finds CR but not <CR>
9275 (?:[IB]<) # Optional markup
9276 $qasked # The command name
9283 ( # The command help:
9285 (?:[IB]<) # Optional markup
9286 $qasked # The command name
9287 ([\s\S]*?) # Lines starting with tabs
9291 ) # Line not starting with space
9292 # (Next command's help)
9296 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
9300 print_help("B<$asked> is not a debugger command.\n");
9302 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
9303 } ## end sub cmd_pre580_h
9305 =head2 Old C<W> command
9307 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
9315 # Delete all watch expressions.
9316 if ( $cmd =~ /^$/ ) {
9318 # No watching is going on.
9321 # Kill all the watch expressions and values.
9322 @to_watch = @old_watch = ();
9325 # Add a watch expression.
9326 elsif ( $cmd =~ /^(.*)/s ) {
9328 # add it to the list to be watched.
9331 # Get the current value of the expression.
9332 # Doesn't handle expressions returning list values!
9335 $val = ( defined $val ) ? "'$val'" : 'undef';
9338 push @old_watch, $val;
9340 # We're watching stuff.
9343 } ## end elsif ($cmd =~ /^(.*)/s)
9344 } ## end sub cmd_pre580_W
9346 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
9348 The debugger used to have a bunch of nearly-identical code to handle
9349 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
9350 C<cmd_prepost> unify all this into one set of code to handle the
9351 appropriate actions.
9353 =head2 C<cmd_pre590_prepost>
9355 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
9356 do something destructive. In pre 5.8 debuggers, the default action was to
9357 delete all the actions.
9361 sub cmd_pre590_prepost {
9363 my $line = shift || '*';
9366 return &cmd_prepost( $cmd, $line, $dbline );
9367 } ## end sub cmd_pre590_prepost
9369 =head2 C<cmd_prepost>
9371 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
9372 Since the lists of actions are all held in arrays that are pointed to by
9373 references anyway, all we have to do is pick the right array reference and
9374 then use generic code to all, delete, or list actions.
9381 # No action supplied defaults to 'list'.
9382 my $line = shift || '?';
9384 # Figure out what to put in the prompt.
9387 # Make sure we have some array or another to address later.
9388 # This means that if ssome reason the tests fail, we won't be
9389 # trying to stash actions or delete them from the wrong place.
9392 # < - Perl code to run before prompt.
9393 if ( $cmd =~ /^\</o ) {
9394 $which = 'pre-perl';
9398 # > - Perl code to run after prompt.
9399 elsif ( $cmd =~ /^\>/o ) {
9400 $which = 'post-perl';
9404 # { - first check for properly-balanced braces.
9405 elsif ( $cmd =~ /^\{/o ) {
9406 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
9408 "$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n";
9411 # Properly balanced. Pre-prompt debugger actions.
9413 $which = 'pre-debugger';
9416 } ## end elsif ( $cmd =~ /^\{/o )
9418 # Did we find something that makes sense?
9420 print $OUT "Confused by command: $cmd\n";
9427 if ( $line =~ /^\s*\?\s*$/o ) {
9430 # Nothing there. Complain.
9431 print $OUT "No $which actions.\n";
9435 # List the actions in the selected list.
9436 print $OUT "$which commands:\n";
9437 foreach my $action (@$aref) {
9438 print $OUT "\t$cmd -- $action\n";
9441 } ## end if ( $line =~ /^\s*\?\s*$/o)
9443 # Might be a delete.
9445 if ( length($cmd) == 1 ) {
9446 if ( $line =~ /^\s*\*\s*$/o ) {
9448 # It's a delete. Get rid of the old actions in the
9451 print $OUT "All $cmd actions cleared.\n";
9455 # Replace all the actions. (This is a <, >, or {).
9456 @$aref = action($line);
9458 } ## end if ( length($cmd) == 1)
9459 elsif ( length($cmd) == 2 ) {
9461 # Add the action to the line. (This is a <<, >>, or {{).
9462 push @$aref, action($line);
9466 # <<<, >>>>, {{{{{{ ... something not a command.
9468 "Confused by strange length of $which command($cmd)...\n";
9470 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
9472 } ## end sub cmd_prepost
9476 Contains the C<at_exit> routine that the debugger uses to issue the
9477 C<Debugged program terminated ...> message after the program completes. See
9478 the C<END> block documentation for more details.
9485 "Debugged program terminated. Use 'q' to quit or 'R' to restart.";
9488 package DB; # Do not trace this 1; below!