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 $filename for C<eval>ed strings looks
194 =head1 DEBUGGER STARTUP
196 When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
197 non-interactive sessions, C<.perldb> for interactive ones) that can set a number
198 of options. In addition, this file may define a subroutine C<&afterinit>
199 that will be executed (in the debugger's context) after the debugger has
202 Next, it checks the C<PERLDB_OPTS> environment variable and treats its
203 contents as the argument of a C<o> command in the debugger.
205 =head2 STARTUP-ONLY OPTIONS
207 The following options can only be specified at startup.
208 To set them in your rcfile, add a call to
209 C<&parse_options("optionName=new_value")>.
215 the TTY to use for debugging i/o.
219 if set, goes in NonStop mode. On interrupt, if TTY is not set,
220 uses the value of noTTY or F<$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
515 BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
519 $^V =~ /^v(\d+\.\d+)/;
520 feature->import(":$1");
523 # Debugger for Perl 5.00x; perl5db.pl patch level:
524 use vars qw($VERSION $header);
526 $VERSION = '1.39_01';
528 $header = "perl5db.pl version $VERSION";
530 =head1 DEBUGGER ROUTINES
534 This function replaces straight C<eval()> inside the debugger; it simplifies
535 the process of evaluating code in the user's context.
537 The code to be evaluated is passed via the package global variable
538 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
540 Before we do the C<eval()>, we preserve the current settings of C<$trace>,
541 C<$single>, C<$^D> and C<$usercontext>. The latter contains the
542 preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
543 user's current package, grabbed when C<DB::DB> got control. This causes the
544 proper context to be used when the eval is actually done. Afterward, we
545 restore C<$trace>, C<$single>, and C<$^D>.
547 Next we need to handle C<$@> without getting confused. We save C<$@> in a
548 local lexical, localize C<$saved[0]> (which is where C<save()> will put
549 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
550 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
551 considered sane by the debugger. If there was an C<eval()> error, we print
552 it on the debugger's output. If C<$onetimedump> is defined, we call
553 C<dumpit> if it's set to 'dump', or C<methods> if it's set to
554 'methods'. Setting it to something else causes the debugger to do the eval
555 but not print the result - handy if you want to do something else with it
556 (the "watch expressions" code does this to get the value of the watch
557 expression but not show it unless it matters).
559 In any case, we then return the list of output from C<eval> to the caller,
560 and unwinding restores the former version of C<$@> in C<@saved> as well
561 (the localization of C<$saved[0]> goes away at the end of this scope).
563 =head3 Parameters and variables influencing execution of DB::eval()
565 C<DB::eval> isn't parameterized in the standard way; this is to keep the
566 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
567 The variables listed below influence C<DB::eval()>'s execution directly.
571 =item C<$evalarg> - the thing to actually be eval'ed
573 =item C<$trace> - Current state of execution tracing
575 =item C<$single> - Current state of single-stepping
577 =item C<$onetimeDump> - what is to be displayed after the evaluation
579 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
583 The following variables are altered by C<DB::eval()> during its execution. They
584 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
588 =item C<@res> - used to capture output from actual C<eval>.
590 =item C<$otrace> - saved value of C<$trace>.
592 =item C<$osingle> - saved value of C<$single>.
594 =item C<$od> - saved value of C<$^D>.
596 =item C<$saved[0]> - saved value of C<$@>.
598 =item $\ - for output of C<$@> if there is an evaluation error.
602 =head3 The problem of lexicals
604 The context of C<DB::eval()> presents us with some problems. Obviously,
605 we want to be 'sandboxed' away from the debugger's internals when we do
606 the eval, but we need some way to control how punctuation variables and
607 debugger globals are used.
609 We can't use local, because the code inside C<DB::eval> can see localized
610 variables; and we can't use C<my> either for the same reason. The code
611 in this routine compromises and uses C<my>.
613 After this routine is over, we don't have user code executing in the debugger's
614 context, so we can use C<my> freely.
618 ############################################## Begin lexical danger zone
620 # 'my' variables used here could leak into (that is, be visible in)
621 # the context that the code being evaluated is executing in. This means that
622 # the code could modify the debugger's variables.
624 # Fiddling with the debugger's context could be Bad. We insulate things as
686 # Used to save @ARGV and extract any debugger-related flags.
689 # Used to prevent multiple entries to diesignal()
690 # (if for instance diesignal() itself dies)
693 # Used to prevent the debugger from running nonstop
695 use vars qw($second_time);
697 sub _calc_usercontext {
700 # Cancel strict completely for the evaluated code, so the code
701 # the user evaluates won't be affected by it. (Shlomi Fish)
702 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @saved;'
703 . "package $package;"; # this won't let them modify, alas
708 # 'my' would make it visible from user code
709 # but so does local! --tchrist
710 # Remember: this localizes @DB::res, not @main::res.
714 # Try to keep the user code from messing with us. Save these so that
715 # even if the eval'ed code changes them, we can put them back again.
716 # Needed because the user could refer directly to the debugger's
717 # package globals (and any 'my' variables in this containing scope)
718 # inside the eval(), and we want to try to stay safe.
719 local $otrace = $trace;
720 local $osingle = $single;
723 # Untaint the incoming eval() argument.
724 { ($evalarg) = $evalarg =~ /(.*)/s; }
726 # $usercontext built in DB::DB near the comment
727 # "set up the context for DB::eval ..."
728 # Evaluate and save any results.
729 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
731 # Restore those old values.
737 # Save the current value of $@, and preserve it in the debugger's copy
738 # of the saved precious globals.
741 # Since we're only saving $@, we only have to localize the array element
742 # that it will be stored in.
743 local $saved[0]; # Preserve the old value of $@
746 # Now see whether we need to report an error back to the user.
752 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
753 # are package globals.
754 elsif ($onetimeDump) {
755 if ( $onetimeDump eq 'dump' ) {
756 local $option{dumpDepth} = $onetimedumpDepth
757 if defined $onetimedumpDepth;
758 dumpit( $OUT, \@res );
760 elsif ( $onetimeDump eq 'methods' ) {
763 } ## end elsif ($onetimeDump)
767 ############################################## End lexical danger zone
769 # After this point it is safe to introduce lexicals.
770 # The code being debugged will be executing in its own context, and
771 # can't see the inside of the debugger.
773 # However, one should not overdo it: leave as much control from outside as
774 # possible. If you make something a lexical, it's not going to be addressable
775 # from outside the debugger even if you know its name.
777 # This file is automatically included if you do perl -d.
778 # It's probably not useful to include this yourself.
780 # Before venturing further into these twisty passages, it is
781 # wise to read the perldebguts man page or risk the ire of dragons.
783 # (It should be noted that perldebguts will tell you a lot about
784 # the underlying mechanics of how the debugger interfaces into the
785 # Perl interpreter, but not a lot about the debugger itself. The new
786 # comments in this code try to address this problem.)
788 # Note that no subroutine call is possible until &DB::sub is defined
789 # (for subroutines defined outside of the package DB). In fact the same is
790 # true if $deep is not defined.
792 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
794 # modified Perl debugger, to be run from Emacs in perldb-mode
795 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
796 # Johan Vromans -- upgrade to 4.0 pl 10
797 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
798 ########################################################################
800 =head1 DEBUGGER INITIALIZATION
802 The debugger starts up in phases.
806 First, it initializes the environment it wants to run in: turning off
807 warnings during its own compilation, defining variables which it will need
808 to avoid warnings later, setting itself up to not exit when the program
809 terminates, and defaulting to printing return values for the C<r> command.
813 # Needed for the statement after exec():
815 # This BEGIN block is simply used to switch off warnings during debugger
816 # compilation. Probably it would be better practice to fix the warnings,
817 # but this is how it's done at the moment.
822 } # Switch compilation warnings off until another BEGIN.
824 local ($^W) = 0; # Switch run-time warnings off during init.
826 =head2 THREADS SUPPORT
828 If we are running under a threaded Perl, we require threads and threads::shared
829 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
830 threaded debugger control. C<-dt> can also be used to set this.
832 Each new thread will be announced and the debugger prompt will always inform
833 you of each new thread created. It will also indicate the thread id in which
834 we are currently running within the prompt like this:
838 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
839 command prompt. The prompt will show: C<[0]> when running under threads, but
840 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
842 While running under threads, when you set or delete a breakpoint (etc.), this
843 will apply to all threads, not just the currently running one. When you are
844 in a currently executing thread, you will stay there until it completes. With
845 the current implementation it is not currently possible to hop from one thread
848 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
850 Note that threading support was built into the debugger as of Perl version
851 C<5.8.6> and debugger version C<1.2.8>.
856 # ensure we can share our non-threaded variables or no-op
857 if ($ENV{PERL5DB_THREADED}) {
859 require threads::shared;
860 import threads::shared qw(share);
864 print "Threads support enabled\n";
871 # This would probably be better done with "use vars", but that wasn't around
872 # when this code was originally written. (Neither was "use strict".) And on
873 # the principle of not fiddling with something that was working, this was
876 # These variables control the execution of 'dumpvar.pl'.
878 $dumpvar::arrayDepth,
879 $dumpvar::dumpDBFiles,
880 $dumpvar::dumpPackages,
881 $dumpvar::quoteHighBit,
882 $dumpvar::printUndef,
886 # used to control die() reporting in diesignal()
893 # without threads, $filename is not defined until DB::DB is called
894 foreach my $k (keys (%INC)) {
895 &share(\$main::{'_<'.$filename}) if defined $filename;
898 # Command-line + PERLLIB:
899 # Save the contents of @INC before they are modified elsewhere.
902 # This was an attempt to clear out the previous values of various
903 # trapped errors. Apparently it didn't help. XXX More info needed!
904 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
906 # We set these variables to safe values. We don't want to blindly turn
907 # off warnings, because other packages may still want them.
908 $trace = $signal = $single = 0; # Uninitialized warning suppression
909 # (local $^W cannot help - other packages!).
911 # Default to not exiting when program finishes; print the return
912 # value when the 'r' command is used to return from a subroutine.
913 $inhibit_exit = $option{PrintRet} = 1;
915 use vars qw($trace_to_depth);
917 # Default to 1 so the prompt will display the first line.
920 =head1 OPTION PROCESSING
922 The debugger's options are actually spread out over the debugger itself and
923 C<dumpvar.pl>; some of these are variables to be set, while others are
924 subs to be called with a value. To try to make this a little easier to
925 manage, the debugger uses a few data structures to define what options
926 are legal and how they are to be processed.
928 First, the C<@options> array defines the I<names> of all the options that
934 CommandSet HistFile HistSize
935 hashDepth arrayDepth dumpDepth
936 DumpDBFiles DumpPackages DumpReused
937 compactDump veryCompact quote
938 HighBit undefPrint globPrint
939 PrintRet UsageOnly frame
941 ReadLine NonStop LineInfo
942 maxTraceLen recallCommand ShellBang
943 pager tkRunning ornaments
944 signalLevel warnLevel dieLevel
945 inhibit_exit ImmediateStop bareStringify
946 CreateTTY RemotePort windowSize
950 @RememberOnROptions = qw(DollarCaretP);
954 Second, C<optionVars> lists the variables that each option uses to save its
959 use vars qw(%optionVars);
962 hashDepth => \$dumpvar::hashDepth,
963 arrayDepth => \$dumpvar::arrayDepth,
964 CommandSet => \$CommandSet,
965 DumpDBFiles => \$dumpvar::dumpDBFiles,
966 DumpPackages => \$dumpvar::dumpPackages,
967 DumpReused => \$dumpvar::dumpReused,
968 HighBit => \$dumpvar::quoteHighBit,
969 undefPrint => \$dumpvar::printUndef,
970 globPrint => \$dumpvar::globPrint,
971 UsageOnly => \$dumpvar::usageOnly,
972 CreateTTY => \$CreateTTY,
973 bareStringify => \$dumpvar::bareStringify,
975 AutoTrace => \$trace,
976 inhibit_exit => \$inhibit_exit,
977 maxTraceLen => \$maxtrace,
978 ImmediateStop => \$ImmediateStop,
979 RemotePort => \$remoteport,
980 windowSize => \$window,
981 HistFile => \$histfile,
982 HistSize => \$histsize,
987 Third, C<%optionAction> defines the subroutine to be called to process each
992 use vars qw(%optionAction);
995 compactDump => \&dumpvar::compactDump,
996 veryCompact => \&dumpvar::veryCompact,
997 quote => \&dumpvar::quote,
1000 ReadLine => \&ReadLine,
1001 NonStop => \&NonStop,
1002 LineInfo => \&LineInfo,
1003 recallCommand => \&recallCommand,
1004 ShellBang => \&shellBang,
1006 signalLevel => \&signalLevel,
1007 warnLevel => \&warnLevel,
1008 dieLevel => \&dieLevel,
1009 tkRunning => \&tkRunning,
1010 ornaments => \&ornaments,
1011 RemotePort => \&RemotePort,
1012 DollarCaretP => \&DollarCaretP,
1017 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1022 # Note that this list is not complete: several options not listed here
1023 # actually require that dumpvar.pl be loaded for them to work, but are
1024 # not in the table. A subsequent patch will correct this problem; for
1025 # the moment, we're just recommenting, and we are NOT going to change
1027 use vars qw(%optionRequire);
1030 compactDump => 'dumpvar.pl',
1031 veryCompact => 'dumpvar.pl',
1032 quote => 'dumpvar.pl',
1037 There are a number of initialization-related variables which can be set
1038 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1039 variable. These are:
1043 =item C<$rl> - readline control XXX needs more explanation
1045 =item C<$warnLevel> - whether or not debugger takes over warning handling
1047 =item C<$dieLevel> - whether or not debugger takes over die handling
1049 =item C<$signalLevel> - whether or not debugger takes over signal handling
1051 =item C<$pre> - preprompt actions (array reference)
1053 =item C<$post> - postprompt actions (array reference)
1057 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1059 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1065 # These guys may be defined in $ENV{PERL5DB} :
1066 $rl = 1 unless defined $rl;
1067 $warnLevel = 1 unless defined $warnLevel;
1068 $dieLevel = 1 unless defined $dieLevel;
1069 $signalLevel = 1 unless defined $signalLevel;
1070 $pre = [] unless defined $pre;
1071 $post = [] unless defined $post;
1072 $pretype = [] unless defined $pretype;
1073 $CreateTTY = 3 unless defined $CreateTTY;
1074 $CommandSet = '580' unless defined $CommandSet;
1079 share($signalLevel);
1089 The default C<die>, C<warn>, and C<signal> handlers are set up.
1093 warnLevel($warnLevel);
1094 dieLevel($dieLevel);
1095 signalLevel($signalLevel);
1099 The pager to be used is needed next. We try to get it from the
1100 environment first. If it's not defined there, we try to find it in
1101 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1102 then call the C<pager()> function to save the pager name.
1106 # This routine makes sure $pager is set up so that '|' can use it.
1109 # If PAGER is defined in the environment, use it.
1113 # If not, see if Config.pm defines it.
1114 : eval { require Config }
1115 && defined $Config::Config{pager}
1116 ? $Config::Config{pager}
1118 # If not, fall back to 'more'.
1121 unless defined $pager;
1125 We set up the command to be used to access the man pages, the command
1126 recall character (C<!> unless otherwise defined) and the shell escape
1127 character (C<!> unless otherwise defined). Yes, these do conflict, and
1128 neither works in the debugger at the moment.
1134 # Set up defaults for command recall and shell escape (note:
1135 # these currently don't work in linemode debugging).
1136 &recallCommand("!") unless defined $prc;
1137 &shellBang("!") unless defined $psh;
1141 We then set up the gigantic string containing the debugger help.
1142 We also set the limit on the number of arguments we'll display during a
1149 # If we didn't get a default for the length of eval/stack trace args,
1151 $maxtrace = 400 unless defined $maxtrace;
1153 =head2 SETTING UP THE DEBUGGER GREETING
1155 The debugger I<greeting> helps to inform the user how many debuggers are
1156 running, and whether the current debugger is the primary or a child.
1158 If we are the primary, we just hang onto our pid so we'll have it when
1159 or if we start a child debugger. If we are a child, we'll set things up
1160 so we'll have a unique greeting and so the parent will give us our own
1163 We save the current contents of the C<PERLDB_PIDS> environment variable
1164 because we mess around with it. We'll also need to hang onto it because
1165 we'll need it if we restart.
1167 Child debuggers make a label out of the current PID structure recorded in
1168 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1169 yet so the parent will give them one later via C<resetterm()>.
1173 # Save the current contents of the environment; we're about to
1174 # much with it. We'll need this if we have to restart.
1175 use vars qw($ini_pids);
1176 $ini_pids = $ENV{PERLDB_PIDS};
1178 use vars qw ($pids $term_pid);
1180 if ( defined $ENV{PERLDB_PIDS} ) {
1182 # We're a child. Make us a label out of the current PID structure
1183 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1184 # a term yet so the parent will give us one later via resetterm().
1186 my $env_pids = $ENV{PERLDB_PIDS};
1187 $pids = "[$env_pids]";
1189 # Unless we are on OpenVMS, all programs under the DCL shell run under
1192 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1196 $ENV{PERLDB_PIDS} .= "->$$";
1200 } ## end if (defined $ENV{PERLDB_PIDS...
1203 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1204 # child debugger, and mark us as the parent, so we'll know to set up
1205 # more TTY's is we have to.
1206 $ENV{PERLDB_PIDS} = "$$";
1211 use vars qw($pidprompt);
1214 # Sets up $emacs as a synonym for $slave_editor.
1215 use vars qw($slave_editor);
1216 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1218 =head2 READING THE RC FILE
1220 The debugger will read a file of initialization options if supplied. If
1221 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1225 # As noted, this test really doesn't check accurately that the debugger
1226 # is running at a terminal or not.
1228 my $dev_tty = '/dev/tty';
1229 $dev_tty = 'TT:' if ($^O eq 'VMS');
1230 use vars qw($rcfile);
1231 if ( -e $dev_tty ) { # this is the wrong metric!
1232 $rcfile = ".perldb";
1235 $rcfile = "perldb.ini";
1240 The debugger does a safety test of the file to be read. It must be owned
1241 either by the current user or root, and must only be writable by the owner.
1245 # This wraps a safety test around "do" to read and evaluate the init file.
1247 # This isn't really safe, because there's a race
1248 # between checking and opening. The solution is to
1249 # open and fstat the handle, but then you have to read and
1250 # eval the contents. But then the silly thing gets
1251 # your lexical scope, which is unfortunate at best.
1255 # Just exactly what part of the word "CORE::" don't you understand?
1256 local $SIG{__WARN__};
1257 local $SIG{__DIE__};
1259 unless ( is_safe_file($file) ) {
1260 CORE::warn <<EO_GRIPE;
1261 perldb: Must not source insecure rcfile $file.
1262 You or the superuser must be the owner, and it must not
1263 be writable by anyone but its owner.
1266 } ## end unless (is_safe_file($file...
1269 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1270 } ## end sub safe_do
1272 # This is the safety test itself.
1274 # Verifies that owner is either real user or superuser and that no
1275 # one but owner may write to it. This function is of limited use
1276 # when called on a path instead of upon a handle, because there are
1277 # no guarantees that filename (by dirent) whose file (by ino) is
1278 # eventually accessed is the same as the one tested.
1279 # Assumes that the file's existence is not in doubt.
1282 stat($path) || return; # mysteriously vaporized
1283 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1285 return 0 if $uid != 0 && $uid != $<;
1286 return 0 if $mode & 022;
1288 } ## end sub is_safe_file
1290 # If the rcfile (whichever one we decided was the right one to read)
1291 # exists, we safely do it.
1293 safe_do("./$rcfile");
1296 # If there isn't one here, try the user's home directory.
1297 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1298 safe_do("$ENV{HOME}/$rcfile");
1301 # Else try the login directory.
1302 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1303 safe_do("$ENV{LOGDIR}/$rcfile");
1306 # If the PERLDB_OPTS variable has options in it, parse those out next.
1307 if ( defined $ENV{PERLDB_OPTS} ) {
1308 parse_options( $ENV{PERLDB_OPTS} );
1313 The last thing we do during initialization is determine which subroutine is
1314 to be used to obtain a new terminal when a new debugger is started. Right now,
1315 the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
1320 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1321 # Works if you're running an xterm or xterm-like window, or you're on
1322 # OS/2, or on Mac OS X. This may need some expansion.
1324 if (not defined &get_fork_TTY) # only if no routine exists
1326 if ( defined $remoteport ) {
1327 # Expect an inetd-like server
1328 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1330 elsif (defined $ENV{TERM} # If we know what kind
1331 # of terminal this is,
1332 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1333 and defined $ENV{DISPLAY} # and what display it's on,
1336 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1338 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1339 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1341 elsif ( $^O eq 'darwin' # If this is Mac OS X
1342 and defined $ENV{TERM_PROGRAM} # and we're running inside
1343 and $ENV{TERM_PROGRAM}
1344 eq 'Apple_Terminal' # Terminal.app
1347 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1349 } ## end if (not defined &get_fork_TTY...
1351 # untaint $^O, which may have been tainted by the last statement.
1352 # see bug [perl #24674]
1356 # Here begin the unreadable code. It needs fixing.
1358 =head2 RESTART PROCESSING
1360 This section handles the restart command. When the C<R> command is invoked, it
1361 tries to capture all of the state it can into environment variables, and
1362 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1363 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1364 the R command stuffed into the environment variables.
1366 PERLDB_RESTART - flag only, contains no restart data itself.
1367 PERLDB_HIST - command history, if it's available
1368 PERLDB_ON_LOAD - breakpoints set by the rc file
1369 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1370 PERLDB_VISITED - files that had breakpoints
1371 PERLDB_FILE_... - breakpoints for a file
1372 PERLDB_OPT - active options
1373 PERLDB_INC - the original @INC
1374 PERLDB_PRETYPE - preprompt debugger actions
1375 PERLDB_PRE - preprompt Perl code
1376 PERLDB_POST - post-prompt Perl code
1377 PERLDB_TYPEAHEAD - typeahead captured by readline()
1379 We chug through all these variables and plug the values saved in them
1380 back into the appropriate spots in the debugger.
1384 use vars qw(@hist @truehist %postponed_file @typeahead);
1386 if ( exists $ENV{PERLDB_RESTART} ) {
1388 # We're restarting, so we don't need the flag that says to restart anymore.
1389 delete $ENV{PERLDB_RESTART};
1392 @hist = get_list('PERLDB_HIST');
1393 %break_on_load = get_list("PERLDB_ON_LOAD");
1394 %postponed = get_list("PERLDB_POSTPONE");
1398 share(%break_on_load);
1401 # restore breakpoints/actions
1402 my @had_breakpoints = get_list("PERLDB_VISITED");
1403 for my $file_idx ( 0 .. $#had_breakpoints ) {
1404 my $filename = $had_breakpoints[$file_idx];
1405 my %pf = get_list("PERLDB_FILE_$file_idx");
1406 $postponed_file{ $filename } = \%pf if %pf;
1407 my @lines = sort {$a <=> $b} keys(%pf);
1408 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1409 for my $line_idx (0 .. $#lines) {
1410 _set_breakpoint_enabled_status(
1413 ($enabled_statuses[$line_idx] ? 1 : ''),
1419 my %opt = get_list("PERLDB_OPT");
1421 while ( ( $opt, $val ) = each %opt ) {
1422 $val =~ s/[\\\']/\\$1/g;
1423 parse_options("$opt'$val'");
1426 # restore original @INC
1427 @INC = get_list("PERLDB_INC");
1430 # return pre/postprompt actions and typeahead buffer
1431 $pretype = [ get_list("PERLDB_PRETYPE") ];
1432 $pre = [ get_list("PERLDB_PRE") ];
1433 $post = [ get_list("PERLDB_POST") ];
1434 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1435 } ## end if (exists $ENV{PERLDB_RESTART...
1437 =head2 SETTING UP THE TERMINAL
1439 Now, we'll decide how the debugger is going to interact with the user.
1440 If there's no TTY, we set the debugger to run non-stop; there's not going
1441 to be anyone there to enter commands.
1445 use vars qw($notty $runnonstop $console $tty $LINEINFO);
1446 use vars qw($lineinfo $doccmd);
1455 If there is a TTY, we have to determine who it belongs to before we can
1456 proceed. If this is a slave editor or graphical debugger (denoted by
1457 the first command-line switch being '-emacs'), we shift this off and
1458 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1464 # Is Perl being run from a slave editor or graphical debugger?
1465 # If so, don't use readline, and set $slave_editor = 1.
1467 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1468 $rl = 0, shift(@main::ARGV) if $slave_editor;
1470 #require Term::ReadLine;
1474 We then determine what the console should be on various systems:
1478 =item * Cygwin - We use C<stdin> instead of a separate device.
1482 if ( $^O eq 'cygwin' ) {
1484 # /dev/tty is binary. use stdin for textmode
1488 =item * Unix - use C</dev/tty>.
1492 elsif ( -e "/dev/tty" ) {
1493 $console = "/dev/tty";
1496 =item * Windows or MSDOS - use C<con>.
1500 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1504 =item * VMS - use C<sys$command>.
1510 # everything else is ...
1511 $console = "sys\$command";
1518 Several other systems don't use a specific console. We C<undef $console>
1519 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1520 with a slave editor, Epoc).
1524 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1526 # /dev/tty is binary. use stdin for textmode
1530 if ( $^O eq 'NetWare' ) {
1532 # /dev/tty is binary. use stdin for textmode
1536 # In OS/2, we need to use STDIN to get textmode too, even though
1537 # it pretty much looks like Unix otherwise.
1538 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1543 # EPOC also falls into the 'got to use STDIN' camp.
1544 if ( $^O eq 'epoc' ) {
1550 If there is a TTY hanging around from a parent, we use that as the console.
1554 $console = $tty if defined $tty;
1556 =head2 SOCKET HANDLING
1558 The debugger is capable of opening a socket and carrying out a debugging
1559 session over the socket.
1561 If C<RemotePort> was defined in the options, the debugger assumes that it
1562 should try to start a debugging session on that port. It builds the socket
1563 and then tries to connect the input and output filehandles to it.
1567 # Handle socket stuff.
1569 if ( defined $remoteport ) {
1571 # If RemotePort was defined in the options, connect input and output
1573 $IN = $OUT = connect_remoteport();
1574 } ## end if (defined $remoteport)
1578 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1579 this is probably a situation where multiple debuggers are running (for example,
1580 a backticked command that starts up another debugger). We create a new IN and
1581 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1589 # Two debuggers running (probably a system or a backtick that invokes
1590 # the debugger itself under the running one). create a new IN and OUT
1591 # filehandle, and do the necessary mojo to create a new tty if we
1592 # know how, and we can.
1593 create_IN_OUT(4) if $CreateTTY & 4;
1596 # If we have a console, check to see if there are separate ins and
1597 # outs to open. (They are assumed identical if not.)
1599 my ( $i, $o ) = split /,/, $console;
1600 $o = $i unless defined $o;
1602 # read/write on in, or just read, or read on STDIN.
1604 || open( IN, "<$i" )
1605 || open( IN, "<&STDIN" );
1607 # read/write/create/clobber out, or write/create/clobber out,
1608 # or merge with STDERR, or merge with STDOUT.
1610 || open( OUT, ">$o" )
1611 || open( OUT, ">&STDERR" )
1612 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1614 } ## end if ($console)
1615 elsif ( not defined $console ) {
1617 # No console. Open STDIN.
1618 open( IN, "<&STDIN" );
1620 # merge with STDERR, or with STDOUT.
1621 open( OUT, ">&STDERR" )
1622 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1623 $console = 'STDIN/OUT';
1624 } ## end elsif (not defined $console)
1626 # Keep copies of the filehandles so that when the pager runs, it
1627 # can close standard input without clobbering ours.
1628 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1629 } ## end elsif (from if(defined $remoteport))
1631 # Unbuffer DB::OUT. We need to see responses right away.
1632 my $previous = select($OUT);
1633 $| = 1; # for DB::OUT
1636 # Line info goes to debugger output unless pointed elsewhere.
1637 # Pointing elsewhere makes it possible for slave editors to
1638 # keep track of file and position. We have both a filehandle
1639 # and a I/O description to keep track of.
1640 $LINEINFO = $OUT unless defined $LINEINFO;
1641 $lineinfo = $console unless defined $lineinfo;
1642 # share($LINEINFO); # <- unable to share globs
1647 To finish initialization, we show the debugger greeting,
1648 and then call the C<afterinit()> subroutine if there is one.
1652 # Show the debugger greeting.
1653 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1654 unless ($runnonstop) {
1657 if ( $term_pid eq '-1' ) {
1658 print $OUT "\nDaughter DB session started...\n";
1661 print $OUT "\nLoading DB routines from $header\n";
1664 $slave_editor ? "enabled" : "available", ".\n"
1667 "\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
1668 } ## end else [ if ($term_pid eq '-1')
1669 } ## end unless ($runnonstop)
1670 } ## end else [ if ($notty)
1672 # XXX This looks like a bug to me.
1673 # Why copy to @ARGS and then futz with @args?
1676 # Make sure backslashes before single quotes are stripped out, and
1677 # keep args unless they are numeric (XXX why?)
1678 # s/\'/\\\'/g; # removed while not justified understandably
1679 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1682 # If there was an afterinit() sub defined, call it. It will get
1683 # executed in our scope, so it can fiddle with debugger globals.
1684 if ( defined &afterinit ) { # May be defined in $rcfile
1688 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1689 use vars qw($I_m_init);
1693 ############################################################ Subroutines
1699 This gigantic subroutine is the heart of the debugger. Called before every
1700 statement, its job is to determine if a breakpoint has been reached, and
1701 stop if so; read commands from the user, parse them, and execute
1702 them, and then send execution off to the next statement.
1704 Note that the order in which the commands are processed is very important;
1705 some commands earlier in the loop will actually alter the C<$cmd> variable
1706 to create other commands to be executed later. This is all highly I<optimized>
1707 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1708 see what's happening in any given command.
1738 # lock the debugger and get the thread id for the prompt
1742 my ($prefix, $after, $infix);
1746 if ($ENV{PERL5DB_THREADED}) {
1747 $tid = eval { "[".threads->tid."]" };
1750 # Check for whether we should be running continuously or not.
1751 # _After_ the perl program is compiled, $single is set to 1:
1752 if ( $single and not $second_time++ ) {
1754 # Options say run non-stop. Run until we get an interrupt.
1755 if ($runnonstop) { # Disable until signal
1756 # If there's any call stack in place, turn off single
1757 # stepping into subs throughout the stack.
1758 for ( my $i = 0 ; $i <= $stack_depth ; ) {
1759 $stack[ $i++ ] &= ~1;
1762 # And we are now no longer in single-step mode.
1765 # If we simply returned at this point, we wouldn't get
1766 # the trace info. Fall on through.
1768 } ## end if ($runnonstop)
1770 elsif ($ImmediateStop) {
1772 # We are supposed to stop here; XXX probably a break.
1773 $ImmediateStop = 0; # We've processed it; turn it off
1774 $signal = 1; # Simulate an interrupt to force
1775 # us into the command loop
1777 } ## end if ($single and not $second_time...
1779 # If we're in single-step mode, or an interrupt (real or fake)
1780 # has occurred, turn off non-stop mode.
1781 $runnonstop = 0 if $single or $signal;
1783 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1784 # The code being debugged may have altered them.
1787 # Since DB::DB gets called after every line, we can use caller() to
1788 # figure out where we last were executing. Sneaky, eh? This works because
1789 # caller is returning all the extra information when called from the
1791 local ( $package, $filename, $line ) = caller;
1792 $filename_ini = $filename;
1794 # set up the context for DB::eval, so it can properly execute
1795 # code on behalf of the user. We add the package in so that the
1796 # code is eval'ed in the proper package (not in the debugger!).
1797 local $usercontext = _calc_usercontext($package);
1799 # Create an alias to the active file magical array to simplify
1801 local (*dbline) = $main::{ '_<' . $filename };
1803 # Last line in the program.
1806 # if we have something here, see if we should break.
1808 && _is_breakpoint_enabled($filename, $line)
1809 && ( my ( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1812 # Stop if the stop criterion says to just stop.
1813 if ( $stop eq '1' ) {
1817 # It's a conditional stop; eval it in the user's context and
1818 # see if we should stop. If so, remove the one-time sigil.
1820 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1822 # If the breakpoint is temporary, then delete its enabled status.
1823 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1824 _cancel_breakpoint_temp_enabled_status($filename, $line);
1827 } ## end if ($dbline{$line} && ...
1829 # Preserve the current stop-or-not, and see if any of the W
1830 # (watch expressions) has changed.
1831 my $was_signal = $signal;
1833 # If we have any watch expressions ...
1835 for ( my $n = 0 ; $n <= $#to_watch ; $n++ ) {
1836 $evalarg = $to_watch[$n];
1837 local $onetimeDump; # Tell DB::eval() to not output results
1839 # Fix context DB::eval() wants to return an array, but
1840 # we need a scalar here.
1841 my ($val) = join( "', '", &eval );
1842 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
1845 if ( $val ne $old_watch[$n] ) {
1847 # Yep! Show the difference, and fake an interrupt.
1850 Watchpoint $n:\t$to_watch[$n] changed:
1851 old value:\t$old_watch[$n]
1854 $old_watch[$n] = $val;
1855 } ## end if ($val ne $old_watch...
1856 } ## end for (my $n = 0 ; $n <= ...
1857 } ## end if ($trace & 2)
1859 =head2 C<watchfunction()>
1861 C<watchfunction()> is a function that can be defined by the user; it is a
1862 function which will be run on each entry to C<DB::DB>; it gets the
1863 current package, filename, and line as its parameters.
1865 The watchfunction can do anything it likes; it is executing in the
1866 debugger's context, so it has access to all of the debugger's internal
1867 data structures and functions.
1869 C<watchfunction()> can control the debugger's actions. Any of the following
1870 will cause the debugger to return control to the user's program after
1871 C<watchfunction()> executes:
1877 Returning a false value from the C<watchfunction()> itself.
1881 Altering C<$single> to a false value.
1885 Altering C<$signal> to a false value.
1889 Turning off the C<4> bit in C<$trace> (this also disables the
1890 check for C<watchfunction()>. This can be done with
1898 # If there's a user-defined DB::watchfunction, call it with the
1899 # current package, filename, and line. The function executes in
1901 if ( $trace & 4 ) { # User-installed watch
1903 if watchfunction( $package, $filename, $line )
1906 and not( $trace & ~4 );
1907 } ## end if ($trace & 4)
1909 # Pick up any alteration to $signal in the watchfunction, and
1910 # turn off the signal now.
1911 $was_signal = $signal;
1914 =head2 GETTING READY TO EXECUTE COMMANDS
1916 The debugger decides to take control if single-step mode is on, the
1917 C<t> command was entered, or the user generated a signal. If the program
1918 has fallen off the end, we set things up so that entering further commands
1919 won't cause trouble, and we say that the program is over.
1923 # Make sure that we always print if asked for explicitly regardless
1924 # of $trace_to_depth .
1925 my $explicit_stop = ($single || $was_signal);
1927 # Check to see if we should grab control ($single true,
1928 # trace set appropriately, or we got a signal).
1929 if ( $explicit_stop || ( $trace & 1 ) ) {
1931 # Yes, grab control.
1932 if ($slave_editor) {
1934 # Tell the editor to update its position.
1935 $position = "\032\032$filename:$line:0\n";
1936 print_lineinfo($position);
1941 Special check: if we're in package C<DB::fake>, we've gone through the
1942 C<END> block at least once. We set up everything so that we can continue
1943 to enter commands and have a valid context to be in.
1947 elsif ( $package eq 'DB::fake' ) {
1949 # Fallen off the end already.
1952 Debugged program terminated. Use B<q> to quit or B<R> to restart,
1953 use B<o> I<inhibit_exit> to avoid stopping after program termination,
1954 B<h q>, B<h R> or B<h o> to get additional info.
1957 # Set the DB::eval context appropriately.
1959 $usercontext = _calc_usercontext($package);
1960 } ## end elsif ($package eq 'DB::fake')
1964 If the program hasn't finished executing, we scan forward to the
1965 next executable line, print that out, build the prompt from the file and line
1966 number information, and print that.
1973 # Still somewhere in the midst of execution. Set up the
1975 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
1976 # Perl 5 ones (sorry, we don't print Klingon
1979 $prefix = $sub =~ /::/ ? "" : ($package . '::');
1980 $prefix .= "$sub($filename:";
1981 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" );
1983 # Break up the prompt if it's really long.
1984 if ( length($prefix) > 30 ) {
1985 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
1991 $position = "$prefix$line$infix$dbline[$line]$after";
1994 # Print current line info, indenting if necessary.
1996 print_lineinfo( ' ' x $stack_depth,
1997 "$line:\t$dbline[$line]$after" );
2000 depth_print_lineinfo($explicit_stop, $position);
2003 # Scan forward, stopping at either the end or the next
2005 for ( my $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i )
2008 # Drop out on null statements, block closers, and comments.
2009 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
2011 # Drop out if the user interrupted us.
2014 # Append a newline if the line doesn't have one. Can happen
2015 # in eval'ed text, for instance.
2016 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" );
2018 # Next executable line.
2019 my $incr_pos = "$prefix$i$infix$dbline[$i]$after";
2020 $position .= $incr_pos;
2023 # Print it indented if tracing is on.
2024 print_lineinfo( ' ' x $stack_depth,
2025 "$i:\t$dbline[$i]$after" );
2028 depth_print_lineinfo($explicit_stop, $incr_pos);
2030 } ## end for ($i = $line + 1 ; $i...
2031 } ## end else [ if ($slave_editor)
2032 } ## end if ($single || ($trace...
2036 If there's an action to be executed for the line we stopped at, execute it.
2037 If there are any preprompt actions, execute those as well.
2041 # If there's an action, do it now.
2042 $evalarg = $action, &eval if $action;
2044 # Are we nested another level (e.g., did we evaluate a function
2045 # that had a breakpoint in it at the debugger prompt)?
2046 if ( $single || $was_signal ) {
2048 # Yes, go down a level.
2049 local $level = $level + 1;
2051 # Do any pre-prompt actions.
2052 foreach $evalarg (@$pre) {
2056 # Complain about too much recursion if we passed the limit.
2057 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
2060 # The line we're currently on. Set $incr to -1 to stay here
2061 # until we get a command that tells us to advance.
2063 $incr = -1; # for backward motion.
2065 # Tack preprompt debugger actions ahead of any actual input.
2066 @typeahead = ( @$pretype, @typeahead );
2068 =head2 WHERE ARE WE?
2070 XXX Relocate this section?
2072 The debugger normally shows the line corresponding to the current line of
2073 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2074 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2076 C<$incr> controls by how many lines the I<current> line should move forward
2077 after a command is executed. If set to -1, this indicates that the I<current>
2078 line shouldn't change.
2080 C<$start> is the I<current> line. It is used for things like knowing where to
2081 move forwards or backwards from when doing an C<L> or C<-> command.
2083 C<$max> tells the debugger where the last line of the current file is. It's
2084 used to terminate loops most often.
2086 =head2 THE COMMAND LOOP
2088 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2095 The outer part of the loop, starting at the C<CMD> label. This loop
2096 reads a command and then executes it.
2100 The inner part of the loop, starting at the C<PIPE> label. This part
2101 is wholly contained inside the C<CMD> block and only executes a command.
2102 Used to handle commands running inside a pager.
2106 So why have two labels to restart the loop? Because sometimes, it's easier to
2107 have a command I<generate> another command and then re-execute the loop to do
2108 the new command. This is faster, but perhaps a bit more convoluted.
2112 # The big command dispatch loop. It keeps running until the
2113 # user yields up control again.
2115 # If we have a terminal for input, and we get something back
2116 # from readline(), keep on processing.
2123 # We have a terminal, or can get one ...
2124 ( $term || &setterm ),
2126 # ... and it belogs to this PID or we get one for this PID ...
2127 ( $term_pid == $$ or resetterm(1) ),
2129 # ... and we got a line of command input ...
2132 "$pidprompt $tid DB"
2135 . ( '>' x $level ) . " "
2142 # ... try to execute the input as debugger commands.
2144 # Don't stop running.
2147 # No signal is active.
2150 # Handle continued commands (ending with \):
2151 $cmd =~ s/\\$/\n/ && do {
2152 $cmd .= &readline(" cont: ");
2156 =head4 The null command
2158 A newline entered by itself means I<re-execute the last command>. We grab the
2159 command out of C<$laststep> (where it was recorded previously), and copy it
2160 back into C<$cmd> to be executed below. If there wasn't any previous command,
2161 we'll do nothing below (no command will match). If there was, we also save it
2162 in the command history and fall through to allow the command parsing to pick
2167 # Empty input means repeat the last command.
2168 $cmd =~ /^$/ && ( $cmd = $laststep );
2169 chomp($cmd); # get rid of the annoying extra newline
2170 push( @hist, $cmd ) if length($cmd) > 1;
2171 push( @truehist, $cmd );
2175 # This is a restart point for commands that didn't arrive
2176 # via direct user input. It allows us to 'redo PIPE' to
2177 # re-execute command processing without reading a new command.
2179 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2180 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
2181 my ($i) = split( /\s+/, $cmd );
2183 =head3 COMMAND ALIASES
2185 The debugger can create aliases for commands (these are stored in the
2186 C<%alias> hash). Before a command is executed, the command loop looks it up
2187 in the alias hash and substitutes the contents of the alias for the command,
2188 completely replacing it.
2192 # See if there's an alias for the command, and set it up if so.
2195 # Squelch signal handling; we want to keep control here
2196 # if something goes loco during the alias eval.
2197 local $SIG{__DIE__};
2198 local $SIG{__WARN__};
2200 # This is a command, so we eval it in the DEBUGGER's
2201 # scope! Otherwise, we can't see the special debugger
2202 # variables, or get to the debugger's subs. (Well, we
2203 # _could_, but why make it even more complicated?)
2204 eval "\$cmd =~ $alias{$i}";
2207 print $OUT "Couldn't evaluate '$i' alias: $@";
2210 } ## end if ($alias{$i})
2212 =head3 MAIN-LINE COMMANDS
2214 All of these commands work up to and after the program being debugged has
2219 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2220 try to execute further, cleaning any restart-related stuff out of the
2221 environment, and executing with the last value of C<$?>.
2225 $cmd =~ /^q$/ && do {
2231 =head4 C<t> - trace [n]
2233 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2234 If level is specified, set C<$trace_to_depth>.
2238 $cmd =~ /^t(?:\s+(\d+))?$/ && do {
2242 $trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
2243 print $OUT "Trace = "
2245 ? ( $levels ? "on (to level $trace_to_depth)" : "on" )
2250 =head4 C<S> - list subroutines matching/not matching a pattern
2252 Walks through C<%sub>, checking to see whether or not to print the name.
2256 $cmd =~ /^S(\s+(!)?(.+))?$/ && do {
2258 my $Srev = defined $2; # Reverse scan?
2259 my $Spatt = $3; # The pattern (if any) to use.
2260 my $Snocheck = !defined $1; # No args - print all subs.
2262 # Need to make these sane here.
2266 # Search through the debugger's magical hash of subs.
2267 # If $nocheck is true, just print the sub name.
2268 # Otherwise, check it against the pattern. We then use
2269 # the XOR trick to reverse the condition as required.
2270 foreach $subname ( sort( keys %sub ) ) {
2271 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2272 print $OUT $subname, "\n";
2278 =head4 C<X> - list variables in current package
2280 Since the C<V> command actually processes this, just change this to the
2281 appropriate C<V> command and fall through.
2285 $cmd =~ s/^X\b/V $package/;
2287 =head4 C<V> - list variables
2289 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2293 # Bare V commands get the currently-being-debugged package
2295 $cmd =~ /^V$/ && do {
2296 $cmd = "V $package";
2299 # V - show variables in package.
2300 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
2302 # Save the currently selected filehandle and
2303 # force output to debugger's filehandle (dumpvar
2304 # just does "print" for output).
2305 my $savout = select($OUT);
2307 # Grab package name and variables to dump.
2309 my @vars = split( ' ', $2 );
2311 # If main::dumpvar isn't here, get it.
2312 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
2313 if ( defined &main::dumpvar ) {
2315 # We got it. Turn off subroutine entry/exit messages
2316 # for the moment, along with return values.
2320 # must detect sigpipe failures - not catching
2321 # then will cause the debugger to die.
2325 defined $option{dumpDepth}
2326 ? $option{dumpDepth}
2327 : -1, # assume -1 unless specified
2332 # The die doesn't need to include the $@, because
2333 # it will automatically get propagated for us.
2335 die unless $@ =~ /dumpvar print failed/;
2337 } ## end if (defined &main::dumpvar)
2340 # Couldn't load dumpvar.
2341 print $OUT "dumpvar.pl not available.\n";
2344 # Restore the output filehandle, and go round again.
2349 =head4 C<x> - evaluate and print an expression
2351 Hands the expression off to C<DB::eval>, setting it up to print the value
2352 via C<dumpvar.pl> instead of just printing it directly.
2356 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval()
2357 $onetimeDump = 'dump'; # main::dumpvar shows the output
2359 # handle special "x 3 blah" syntax XXX propagate
2360 # doc back to special variables.
2361 if ( $cmd =~ s/^\s*(\d+)(?=\s)/ / ) {
2362 $onetimedumpDepth = $1;
2366 =head4 C<m> - print methods
2368 Just uses C<DB::methods> to determine what methods are available.
2372 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do {
2377 # m expr - set up DB::eval to do the work
2378 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval()
2379 $onetimeDump = 'methods'; # method output gets used there
2382 =head4 C<f> - switch files
2386 $cmd =~ /^f\b\s*(.*)/ && do {
2390 # help for no arguments (old-style was return from sub).
2393 "The old f command is now the r command.\n"; # hint
2394 print $OUT "The new f command switches filenames.\n";
2396 } ## end if (!$file)
2398 # if not in magic file list, try a close match.
2399 if ( !defined $main::{ '_<' . $file } ) {
2400 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2402 $try = substr( $try, 2 );
2403 print $OUT "Choosing $try matching '$file':\n";
2406 } ## end if (($try) = grep(m#^_<.*$file#...
2407 } ## end if (!defined $main::{ ...
2409 # If not successfully switched now, we failed.
2410 if ( !defined $main::{ '_<' . $file } ) {
2411 print $OUT "No file matching '$file' is loaded.\n";
2415 # We switched, so switch the debugger internals around.
2416 elsif ( $file ne $filename ) {
2417 *dbline = $main::{ '_<' . $file };
2422 } ## end elsif ($file ne $filename)
2424 # We didn't switch; say we didn't.
2426 print $OUT "Already in $file.\n";
2431 =head4 C<.> - return to last-executed line.
2433 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2434 and then we look up the line in the magical C<%dbline> hash.
2439 $cmd =~ /^\.$/ && do {
2440 $incr = -1; # stay at current line
2442 # Reset everything to the old location.
2444 $filename = $filename_ini;
2445 *dbline = $main::{ '_<' . $filename };
2449 print_lineinfo($position);
2453 =head4 C<-> - back one window
2455 We change C<$start> to be one window back; if we go back past the first line,
2456 we set it to be the first line. We ser C<$incr> to put us back at the
2457 currently-executing line, and then put a C<l $start +> (list one window from
2458 C<$start>) in C<$cmd> to be executed later.
2462 # - - back a window.
2463 $cmd =~ /^-$/ && do {
2465 # back up by a window; go to 1 if back too far.
2466 $start -= $incr + $window + 1;
2467 $start = 1 if $start <= 0;
2468 $incr = $window - 1;
2470 # Generate and execute a "l +" command (handled below).
2471 $cmd = 'l ' . ($start) . '+';
2474 =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>, {, {{>
2476 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2477 problems, most notably that the default case of several commands destroying
2478 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2479 retain the old commands for those who were used to using them or who preferred
2480 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2481 deal with them instead of processing them in-line.
2485 # All of these commands were remapped in perl 5.8.0;
2486 # we send them off to the secondary dispatcher (see below).
2487 $cmd =~ /^([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do {
2488 &cmd_wrapper( $1, $2, $line );
2492 =head4 C<y> - List lexicals in higher scope
2494 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2495 above the current one and then displays then using C<dumpvar.pl>.
2499 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do {
2501 # See if we've got the necessary support.
2502 eval { require PadWalker; PadWalker->VERSION(0.08) }
2505 ? "PadWalker module not found - please install\n"
2510 # Load up dumpvar if we don't have it. If we can, that is.
2511 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
2512 defined &main::dumpvar
2513 or print $OUT "dumpvar.pl not available.\n"
2516 # Got all the modules we need. Find them and print them.
2517 my @vars = split( ' ', $2 || '' );
2520 my $h = eval { PadWalker::peek_my( ( $1 || 0 ) + 1 ) };
2522 # Oops. Can't find it.
2523 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2525 # Show the desired vars with dumplex().
2526 my $savout = select($OUT);
2528 # Have dumplex dump the lexicals.
2529 dumpvar::dumplex( $_, $h->{$_},
2530 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
2537 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2539 All of the commands below this point don't work after the program being
2540 debugged has ended. All of them check to see if the program has ended; this
2541 allows the commands to be relocated without worrying about a 'line of
2542 demarcation' above which commands can be entered anytime, and below which
2545 =head4 C<n> - single step, but don't trace down into subs
2547 Done by setting C<$single> to 2, which forces subs to execute straight through
2548 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2549 so a null command knows what to re-execute.
2554 $cmd =~ /^n$/ && do {
2555 end_report(), next CMD if $finished and $level <= 1;
2557 # Single step, but don't enter subs.
2560 # Save for empty command (repeat last).
2565 =head4 C<s> - single-step, entering subs
2567 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2568 subs. Also saves C<s> as C<$lastcmd>.
2573 $cmd =~ /^s$/ && do {
2575 # Get out and restart the command loop if program
2577 end_report(), next CMD if $finished and $level <= 1;
2579 # Single step should enter subs.
2582 # Save for empty command (repeat last).
2587 =head4 C<c> - run continuously, setting an optional breakpoint
2589 Most of the code for this command is taken up with locating the optional
2590 breakpoint, which is either a subroutine name or a line number. We set
2591 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2592 in this and all call levels above this one.
2596 # c - start continuous execution.
2597 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do {
2599 # Hey, show's over. The debugged program finished
2600 # executing already.
2601 end_report(), next CMD if $finished and $level <= 1;
2603 # Capture the place to put a one-time break.
2606 # Probably not needed, since we finish an interactive
2607 # sub-session anyway...
2608 # local $filename = $filename;
2609 # local *dbline = *dbline; # XXX Would this work?!
2611 # The above question wonders if localizing the alias
2612 # to the magic array works or not. Since it's commented
2613 # out, we'll just leave that to speculation for now.
2615 # If the "subname" isn't all digits, we'll assume it
2616 # is a subroutine name, and try to find it.
2617 if ( $subname =~ /\D/ ) { # subroutine name
2618 # Qualify it to the current package unless it's
2619 # already qualified.
2620 $subname = $package . "::" . $subname
2621 unless $subname =~ /::/;
2623 # find_sub will return "file:line_number" corresponding
2624 # to where the subroutine is defined; we call find_sub,
2625 # break up the return value, and assign it in one
2627 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2629 # Force the line number to be numeric.
2632 # If we got a line number, we found the sub.
2635 # Switch all the debugger's internals around so
2636 # we're actually working with that file.
2638 *dbline = $main::{ '_<' . $filename };
2640 # Mark that there's a breakpoint in this file.
2641 $had_breakpoints{$filename} |= 1;
2643 # Scan forward to the first executable line
2644 # after the 'sub whatever' line.
2646 ++$i while $dbline[$i] == 0 && $i < $max;
2649 # We didn't find a sub by that name.
2651 print $OUT "Subroutine $subname not found.\n";
2654 } ## end if ($subname =~ /\D/)
2656 # At this point, either the subname was all digits (an
2657 # absolute line-break request) or we've scanned through
2658 # the code following the definition of the sub, looking
2659 # for an executable, which we may or may not have found.
2661 # If $i (which we set $subname from) is non-zero, we
2662 # got a request to break at some line somewhere. On
2663 # one hand, if there wasn't any real subroutine name
2664 # involved, this will be a request to break in the current
2665 # file at the specified line, so we have to check to make
2666 # sure that the line specified really is breakable.
2668 # On the other hand, if there was a subname supplied, the
2669 # preceding block has moved us to the proper file and
2670 # location within that file, and then scanned forward
2671 # looking for the next executable line. We have to make
2672 # sure that one was found.
2674 # On the gripping hand, we can't do anything unless the
2675 # current value of $i points to a valid breakable line.
2680 if ( $dbline[$i] == 0 ) {
2681 print $OUT "Line $i not breakable.\n";
2685 # Yes. Set up the one-time-break sigil.
2686 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2687 _enable_breakpoint_temp_enabled_status($filename, $i);
2690 # Turn off stack tracing from here up.
2691 for ( $i = 0 ; $i <= $stack_depth ; ) {
2692 $stack[ $i++ ] &= ~1;
2697 =head4 C<r> - return from a subroutine
2699 For C<r> to work properly, the debugger has to stop execution again
2700 immediately after the return is executed. This is done by forcing
2701 single-stepping to be on in the call level above the current one. If
2702 we are printing return values when a C<r> is executed, set C<$doret>
2703 appropriately, and force us out of the command loop.
2707 # r - return from the current subroutine.
2708 $cmd =~ /^r$/ && do {
2710 # Can't do anything if the program's over.
2711 end_report(), next CMD if $finished and $level <= 1;
2713 # Turn on stack trace.
2714 $stack[$stack_depth] |= 1;
2716 # Print return value unless the stack is empty.
2717 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2721 =head4 C<T> - stack trace
2723 Just calls C<DB::print_trace>.
2727 $cmd =~ /^T$/ && do {
2728 print_trace( $OUT, 1 ); # skip DB
2732 =head4 C<w> - List window around current line.
2734 Just calls C<DB::cmd_w>.
2738 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w( 'w', $1 ); next CMD; };
2740 =head4 C<W> - watch-expression processing.
2742 Just calls C<DB::cmd_W>.
2746 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W( 'W', $1 ); next CMD; };
2748 =head4 C</> - search forward for a string in the source
2750 We take the argument and treat it as a pattern. If it turns out to be a
2751 bad one, we return the error we got from trying to C<eval> it and exit.
2752 If not, we create some code to do the search and C<eval> it so it can't
2757 $cmd =~ /^\/(.*)$/ && do {
2759 # The pattern as a string.
2762 # Remove the final slash.
2763 $inpat =~ s:([^\\])/$:$1:;
2765 # If the pattern isn't null ...
2766 if ( $inpat ne "" ) {
2768 # Turn of warn and die procesing for a bit.
2769 local $SIG{__DIE__};
2770 local $SIG{__WARN__};
2772 # Create the pattern.
2773 eval '$inpat =~ m' . "\a$inpat\a";
2776 # Oops. Bad pattern. No biscuit.
2777 # Print the eval error and go back for more
2783 } ## end if ($inpat ne "")
2785 # Set up to stop on wrap-around.
2788 # Don't move off the current line.
2791 # Done in eval so nothing breaks if the pattern
2792 # does something weird.
2795 # Move ahead one line.
2798 # Wrap if we pass the last line.
2799 $start = 1 if ($start > $max);
2801 # Stop if we have gotten back to this line again,
2802 last if ($start == $end);
2804 # A hit! (Note, though, that we are doing
2805 # case-insensitive matching. Maybe a qr//
2806 # expression would be better, so the user could
2807 # do case-sensitive matching if desired.
2808 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2809 if ($slave_editor) {
2810 # Handle proper escaping in the slave.
2811 print $OUT "\032\032$filename:$start:0\n";
2814 # Just print the line normally.
2815 print $OUT "$start:\t",$dbline[$start],"\n";
2817 # And quit since we found something.
2822 # If we wrapped, there never was a match.
2823 print $OUT "/$pat/: not found\n" if ( $start == $end );
2827 =head4 C<?> - search backward for a string in the source
2829 Same as for C</>, except the loop runs backwards.
2833 # ? - backward pattern search.
2834 $cmd =~ /^\?(.*)$/ && do {
2836 # Get the pattern, remove trailing question mark.
2838 $inpat =~ s:([^\\])\?$:$1:;
2840 # If we've got one ...
2841 if ( $inpat ne "" ) {
2843 # Turn off die & warn handlers.
2844 local $SIG{__DIE__};
2845 local $SIG{__WARN__};
2846 eval '$inpat =~ m' . "\a$inpat\a";
2850 # Ouch. Not good. Print the error.
2855 } ## end if ($inpat ne "")
2857 # Where we are now is where to stop after wraparound.
2860 # Don't move away from this line.
2863 # Search inside the eval to prevent pattern badness
2870 # Wrap if we pass the first line.
2872 $start = $max if ($start <= 0);
2874 # Quit if we get back where we started,
2875 last if ($start == $end);
2878 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2879 if ($slave_editor) {
2880 # Yep, follow slave editor requirements.
2881 print $OUT "\032\032$filename:$start:0\n";
2884 # Yep, just print normally.
2885 print $OUT "$start:\t",$dbline[$start],"\n";
2893 # Say we failed if the loop never found anything,
2894 print $OUT "?$pat?: not found\n" if ( $start == $end );
2898 =head4 C<$rc> - Recall command
2900 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2901 that the terminal supports history). It find the the command required, puts it
2902 into C<$cmd>, and redoes the loop to execute it.
2906 # $rc - recall command.
2907 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do {
2909 # No arguments, take one thing off history.
2910 pop(@hist) if length($cmd) > 1;
2912 # Relative (- found)?
2913 # Y - index back from most recent (by 1 if bare minus)
2914 # N - go to that particular command slot or the last
2915 # thing if nothing following.
2916 $i = $1 ? ( $#hist - ( $2 || 1 ) ) : ( $2 || $#hist );
2918 # Pick out the command desired.
2921 # Print the command to be executed and restart the loop
2922 # with that command in the buffer.
2923 print $OUT $cmd, "\n";
2927 =head4 C<$sh$sh> - C<system()> command
2929 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2930 C<STDOUT> from getting messed up.
2934 # $sh$sh - run a shell command (if it's all ASCII).
2935 # Can't run shell commands with Unicode in the debugger, hmm.
2936 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do {
2943 =head4 C<$rc I<pattern> $rc> - Search command history
2945 Another command to manipulate C<@hist>: this one searches it with a pattern.
2946 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
2950 # $rc pattern $rc - find a command in the history.
2951 $cmd =~ /^$rc([^$rc].*)$/ && do {
2953 # Create the pattern to use.
2956 # Toss off last entry if length is >1 (and it always is).
2957 pop(@hist) if length($cmd) > 1;
2959 # Look backward through the history.
2960 for ( $i = $#hist ; $i ; --$i ) {
2962 # Stop if we find it.
2963 last if $hist[$i] =~ /$pat/;
2969 print $OUT "No such command!\n\n";
2973 # Found it. Put it in the buffer, print it, and process it.
2975 print $OUT $cmd, "\n";
2979 =head4 C<$sh> - Invoke a shell
2981 Uses C<DB::system> to invoke a shell.
2985 # $sh - start a shell.
2986 $cmd =~ /^$sh$/ && do {
2988 # Run the user's shell. If none defined, run Bourne.
2989 # We resume execution when the shell terminates.
2990 &system( $ENV{SHELL} || "/bin/sh" );
2994 =head4 C<$sh I<command>> - Force execution of a command in a shell
2996 Like the above, but the command is passed to the shell. Again, we use
2997 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3001 # $sh command - start a shell and run a command in it.
3002 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do {
3004 # XXX: using csh or tcsh destroys sigint retvals!
3005 #&system($1); # use this instead
3007 # use the user's shell, or Bourne if none defined.
3008 &system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3012 =head4 C<H> - display commands in history
3014 Prints the contents of C<@hist> (if any).
3018 $cmd =~ /^H\b\s*\*/ && do {
3019 @hist = @truehist = ();
3020 print $OUT "History cleansed\n";
3024 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
3026 # Anything other than negative numbers is ignored by
3027 # the (incorrect) pattern, so this test does nothing.
3028 $end = $2 ? ( $#hist - $2 ) : 0;
3030 # Set to the minimum if less than zero.
3031 $hist = 0 if $hist < 0;
3033 # Start at the end of the array.
3034 # Stay in while we're still above the ending value.
3035 # Tick back by one each time around the loop.
3036 for ( $i = $#hist ; $i > $end ; $i-- ) {
3038 # Print the command unless it has no arguments.
3039 print $OUT "$i: ", $hist[$i], "\n"
3040 unless $hist[$i] =~ /^.?$/;
3045 =head4 C<man, doc, perldoc> - look up documentation
3047 Just calls C<runman()> to print the appropriate document.
3051 # man, perldoc, doc - show manual pages.
3052 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do {
3059 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3060 the bottom of the loop.
3064 # p - print (no args): print $_.
3065 $cmd =~ s/^p$/print {\$DB::OUT} \$_/;
3067 # p - print the given expression.
3068 $cmd =~ s/^p\b/print {\$DB::OUT} /;
3070 =head4 C<=> - define command alias
3072 Manipulates C<%alias> to add or list command aliases.
3076 # = - set up a command alias.
3077 $cmd =~ s/^=\s*// && do {
3079 if ( length $cmd == 0 ) {
3081 # No args, get current aliases.
3082 @keys = sort keys %alias;
3084 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3086 # Creating a new alias. $k is alias name, $v is
3089 # can't use $_ or kill //g state
3090 for my $x ( $k, $v ) {
3092 # Escape "alarm" characters.
3096 # Substitute key for value, using alarm chars
3097 # as separators (which is why we escaped them in
3099 $alias{$k} = "s\a$k\a$v\a";
3101 # Turn off standard warn and die behavior.
3102 local $SIG{__DIE__};
3103 local $SIG{__WARN__};
3106 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3108 # Nope. Bad alias. Say so and get out.
3109 print $OUT "Can't alias $k to $v: $@\n";
3114 # We'll only list the new one.
3116 } ## end elsif (my ($k, $v) = ($cmd...
3118 # The argument is the alias to list.
3126 # Messy metaquoting: Trim the substitution code off.
3127 # We use control-G as the delimiter because it's not
3128 # likely to appear in the alias.
3129 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3132 print $OUT "$k\t= $1\n";
3134 elsif ( defined $alias{$k} ) {
3136 # Couldn't trim it off; just print the alias code.
3137 print $OUT "$k\t$alias{$k}\n";
3142 print "No alias for $k\n";
3144 } ## end for my $k (@keys)
3148 =head4 C<source> - read commands from a file.
3150 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3155 # source - read commands from a file (or pipe!) and execute.
3156 $cmd =~ /^source\s+(.*\S)/ && do {
3157 if ( open my $fh, $1 ) {
3159 # Opened OK; stick it in the list of file handles.
3165 &warn("Can't execute '$1': $!\n");
3170 $cmd =~ /^(enable|disable)\s+(\S+)\s*$/ && do {
3171 my ($cmd, $position) = ($1, $2);
3173 my ($fn, $line_num);
3174 if ($position =~ m{\A\d+\z})
3177 $line_num = $position;
3179 elsif ($position =~ m{\A(.*):(\d+)\z})
3181 ($fn, $line_num) = ($1, $2);
3185 &warn("Wrong spec for enable/disable argument.\n");
3189 if (_has_breakpoint_data_ref($fn, $line_num)) {
3190 _set_breakpoint_enabled_status($fn, $line_num,
3191 ($cmd eq 'enable' ? 1 : '')
3195 &warn("No breakpoint set at ${fn}:${line_num}\n");
3202 =head4 C<save> - send current history to a file
3204 Takes the complete history, (not the shrunken version you see with C<H>),
3205 and saves it to the given filename, so it can be replayed using C<source>.
3207 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3211 # save source - write commands to a file for later use
3212 $cmd =~ /^save\s*(.*)$/ && do {
3213 my $file = $1 || '.perl5dbrc'; # default?
3214 if ( open my $fh, "> $file" ) {
3216 # chomp to remove extraneous newlines from source'd files
3217 chomp( my @truelist =
3218 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3220 print $fh join( "\n", @truelist );
3221 print "commands saved in $file\n";
3224 &warn("Can't save debugger commands in '$1': $!\n");
3229 =head4 C<R> - restart
3231 Restart the debugger session.
3233 =head4 C<rerun> - rerun the current session
3235 Return to any given position in the B<true>-history list
3239 # R - restart execution.
3240 # rerun - controlled restart execution.
3241 $cmd =~ /^(R|rerun\s*(.*))$/ && do {
3242 my @args = ($1 eq 'R' ? restart() : rerun($2));
3244 # Close all non-system fds for a clean restart. A more
3245 # correct method would be to close all fds that were not
3246 # open when the process started, but this seems to be
3247 # hard. See "debugger 'R'estart and open database
3248 # connections" on p5p.
3250 my $max_fd = 1024; # default if POSIX can't be loaded
3251 if (eval { require POSIX }) {
3252 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
3255 if (defined $max_fd) {
3256 foreach ($^F+1 .. $max_fd-1) {
3257 next unless open FD_TO_CLOSE, "<&=$_";
3262 # And run Perl again. We use exec() to keep the
3263 # PID stable (and that way $ini_pids is still valid).
3264 exec(@args) || print $OUT "exec failed: $!\n";
3269 =head4 C<|, ||> - pipe output through the pager.
3271 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3272 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3273 pipe to the pager (restoring the output filehandles if this fails). If this
3274 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3275 set C<$signal>, sending us back into the debugger.
3277 We then trim off the pipe symbols and C<redo> the command loop at the
3278 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3283 # || - run command in the pager, with output to DB::OUT.
3284 $cmd =~ /^\|\|?\s*[^|]/ && do {
3285 if ( $pager =~ /^\|/ ) {
3287 # Default pager is into a pipe. Redirect I/O.
3288 open( SAVEOUT, ">&STDOUT" )
3289 || &warn("Can't save STDOUT");
3290 open( STDOUT, ">&OUT" )
3291 || &warn("Can't redirect STDOUT");
3292 } ## end if ($pager =~ /^\|/)
3295 # Not into a pipe. STDOUT is safe.
3296 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3299 # Fix up environment to record we have less if so.
3302 unless ( $piped = open( OUT, $pager ) ) {
3304 # Couldn't open pipe to pager.
3305 &warn("Can't pipe output to '$pager'");
3306 if ( $pager =~ /^\|/ ) {
3308 # Redirect I/O back again.
3309 open( OUT, ">&STDOUT" ) # XXX: lost message
3310 || &warn("Can't restore DB::OUT");
3311 open( STDOUT, ">&SAVEOUT" )
3312 || &warn("Can't restore STDOUT");
3314 } ## end if ($pager =~ /^\|/)
3317 # Redirect I/O. STDOUT already safe.
3318 open( OUT, ">&STDOUT" ) # XXX: lost message
3319 || &warn("Can't restore DB::OUT");
3322 } ## end unless ($piped = open(OUT,...
3324 # Set up broken-pipe handler if necessary.
3325 $SIG{PIPE} = \&DB::catch
3327 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
3329 # Save current filehandle, unbuffer out, and put it back.
3330 $selected = select(OUT);
3333 # Don't put it back if pager was a pipe.
3334 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
3336 # Trim off the pipe symbols and run the command now.
3337 $cmd =~ s/^\|+\s*//;
3341 =head3 END OF COMMAND PARSING
3343 Anything left in C<$cmd> at this point is a Perl expression that we want to
3344 evaluate. We'll always evaluate in the user's context, and fully qualify
3345 any variables we might want to address in the C<DB> package.
3349 # t - turn trace on.
3350 $cmd =~ s/^t\s+(\d+)?/\$DB::trace |= 1;\n/ && do {
3351 $trace_to_depth = $1 ? $stack_depth||0 + $1 : 1E9;
3354 # s - single-step. Remember the last command was 's'.
3355 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' };
3357 # n - single-step, but not into subs. Remember last command
3359 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' };
3363 # Make sure the flag that says "the debugger's running" is
3364 # still on, to make sure we get control again.
3365 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3367 # Run *our* eval that executes in the caller's context.
3370 # Turn off the one-time-dump stuff now.
3372 $onetimeDump = undef;
3373 $onetimedumpDepth = undef;
3375 elsif ( $term_pid == $$ ) {
3376 eval { # May run under miniperl, when not available...
3381 # XXX If this is the master pid, print a newline.
3384 } ## end while (($term || &setterm...
3386 =head3 POST-COMMAND PROCESSING
3388 After each command, we check to see if the command output was piped anywhere.
3389 If so, we go through the necessary code to unhook the pipe and go back to
3390 our standard filehandles for input and output.
3396 # At the end of every command:
3399 # Unhook the pipe mechanism now.
3400 if ( $pager =~ /^\|/ ) {
3402 # No error from the child.
3405 # we cannot warn here: the handle is missing --tchrist
3406 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
3408 # most of the $? crud was coping with broken cshisms
3409 # $? is explicitly set to 0, so this never runs.
3411 print SAVEOUT "Pager '$pager' failed: ";
3413 print SAVEOUT "shell returned -1\n";
3416 print SAVEOUT ( $? & 127 )
3417 ? " (SIG#" . ( $? & 127 ) . ")"
3418 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3421 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3425 # Reopen filehandle for our output (if we can) and
3426 # restore STDOUT (if we can).
3427 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3428 open( STDOUT, ">&SAVEOUT" )
3429 || &warn("Can't restore STDOUT");
3431 # Turn off pipe exception handler if necessary.
3432 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
3434 # Will stop ignoring SIGPIPE if done like nohup(1)
3435 # does SIGINT but Perl doesn't give us a choice.
3436 } ## end if ($pager =~ /^\|/)
3439 # Non-piped "pager". Just restore STDOUT.
3440 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3443 # Close filehandle pager was using, restore the normal one
3446 select($selected), $selected = "" unless $selected eq "";
3450 } ## end if ($piped)
3453 =head3 COMMAND LOOP TERMINATION
3455 When commands have finished executing, we come here. If the user closed the
3456 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3457 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3458 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3459 The interpreter will then execute the next line and then return control to us
3464 # No more commands? Quit.
3465 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
3467 # Evaluate post-prompt commands.
3468 foreach $evalarg (@$post) {
3471 } # if ($single || $signal)
3473 # Put the user's globals back where you found them.
3474 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3478 # The following code may be executed now:
3483 C<sub> is called whenever a subroutine call happens in the program being
3484 debugged. The variable C<$DB::sub> contains the name of the subroutine
3487 The core function of this subroutine is to actually call the sub in the proper
3488 context, capturing its output. This of course causes C<DB::DB> to get called
3489 again, repeating until the subroutine ends and returns control to C<DB::sub>
3490 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3491 return value, and returns its captured copy of the return value as its own
3492 return value. The value then feeds back into the program being debugged as if
3493 C<DB::sub> hadn't been there at all.
3495 C<sub> does all the work of printing the subroutine entry and exit messages
3496 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3497 and also prints the return value if needed (for the C<r> command and if
3498 the 16 bit is set in C<$frame>).
3500 It also tracks the subroutine call depth by saving the current setting of
3501 C<$single> in the C<@stack> package global; if this exceeds the value in
3502 C<$deep>, C<sub> automatically turns on printing of the current depth by
3503 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
3504 of stop/don't stop on entry to subs set as it currently is set.
3506 =head3 C<caller()> support
3508 If C<caller()> is called from the package C<DB>, it provides some
3509 additional data, in the following order:
3515 The package name the sub was in
3517 =item * C<$filename>
3519 The filename it was defined in
3523 The line number it was defined on
3525 =item * C<$subroutine>
3527 The subroutine name; C<(eval)> if an C<eval>().
3531 1 if it has arguments, 0 if not
3533 =item * C<$wantarray>
3535 1 if array context, 0 if scalar context
3537 =item * C<$evaltext>
3539 The C<eval>() text, if any (undefined for C<eval BLOCK>)
3541 =item * C<$is_require>
3543 frame was created by a C<use> or C<require> statement
3547 pragma information; subject to change between versions
3551 pragma information; subject to change between versions
3553 =item * C<@DB::args>
3555 arguments with which the subroutine was invoked
3563 # We need to fully qualify the name ("DB::sub") to make "use strict;"
3564 # happy. -- Shlomi Fish
3566 # Do not use a regex in this subroutine -> results in corrupted memory
3567 # See: [perl #66110]
3569 # lock ourselves under threads
3572 # Whether or not the autoloader was running, a scalar to put the
3573 # sub's return value in (if needed), and an array to put the sub's
3574 # return value in (if needed).
3575 my ( $al, $ret, @ret ) = "";
3576 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
3577 print "creating new thread\n";
3580 # If the last ten characters are '::AUTOLOAD', note we've traced
3581 # into AUTOLOAD for $sub.
3582 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3584 $al = " for $$sub" if defined $$sub;
3587 # We stack the stack pointer and then increment it to protect us
3588 # from a situation that might unwind a whole bunch of call frames
3589 # at once. Localizing the stack pointer means that it will automatically
3590 # unwind the same amount when multiple stack frames are unwound.
3591 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3594 $#stack = $stack_depth;
3596 # Save current single-step setting.
3597 $stack[-1] = $single;
3599 # Turn off all flags except single-stepping.
3602 # If we've gotten really deeply recursed, turn on the flag that will
3603 # make us stop with the 'deep recursion' message.
3604 $single |= 4 if $stack_depth == $deep;
3606 # If frame messages are on ...
3608 $frame & 4 # Extended frame entry message
3610 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3612 # Why -1? But it works! :-(
3613 # Because print_trace will call add 1 to it and then call
3614 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3616 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3618 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3620 # standard frame entry message
3624 # Determine the sub's return type, and capture appropriately.
3627 # Called in array context. call sub and capture output.
3628 # DB::DB will recursively get control again if appropriate; we'll come
3629 # back here when the sub is finished.
3635 # Pop the single-step value back off the stack.
3636 $single |= $stack[ $stack_depth-- ];
3638 # Check for exit trace messages...
3640 $frame & 4 # Extended exit message
3642 print_lineinfo( ' ' x $stack_depth, "out " ),
3643 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3645 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3647 # Standard exit message
3651 # Print the return info if we need to.
3652 if ( $doret eq $stack_depth or $frame & 16 ) {
3654 # Turn off output record separator.
3656 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3658 # Indent if we're printing because of $frame tracing.
3659 print $fh ' ' x $stack_depth if $frame & 16;
3661 # Print the return value.
3662 print $fh "list context return from $sub:\n";
3663 dumpit( $fh, \@ret );
3665 # And don't print it again.
3667 } ## end if ($doret eq $stack_depth...
3668 # And we have to return the return value now.
3670 } ## end if (wantarray)
3674 if ( defined wantarray ) {
3676 # Save the value if it's wanted at all.
3681 # Void return, explicitly.
3686 # Pop the single-step value off the stack.
3687 $single |= $stack[ $stack_depth-- ];
3689 # If we're doing exit messages...
3691 $frame & 4 # Extended messages
3693 print_lineinfo( ' ' x $stack_depth, "out " ),
3694 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3696 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3702 # If we are supposed to show the return value... same as before.
3703 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
3705 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3706 print $fh ( ' ' x $stack_depth ) if $frame & 16;
3709 ? "scalar context return from $sub: "
3710 : "void context return from $sub\n"
3712 dumpit( $fh, $ret ) if defined wantarray;
3714 } ## end if ($doret eq $stack_depth...
3716 # Return the appropriate scalar value.
3718 } ## end else [ if (wantarray)
3725 # lock ourselves under threads
3728 # Whether or not the autoloader was running, a scalar to put the
3729 # sub's return value in (if needed), and an array to put the sub's
3730 # return value in (if needed).
3731 my ( $al, $ret, @ret ) = "";
3732 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3733 print "creating new thread\n";
3736 # If the last ten characters are C'::AUTOLOAD', note we've traced
3737 # into AUTOLOAD for $sub.
3738 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3742 # We stack the stack pointer and then increment it to protect us
3743 # from a situation that might unwind a whole bunch of call frames
3744 # at once. Localizing the stack pointer means that it will automatically
3745 # unwind the same amount when multiple stack frames are unwound.
3746 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3749 $#stack = $stack_depth;
3751 # Save current single-step setting.
3752 $stack[-1] = $single;
3754 # Turn off all flags except single-stepping.
3757 # If we've gotten really deeply recursed, turn on the flag that will
3758 # make us stop with the 'deep recursion' message.
3759 $single |= 4 if $stack_depth == $deep;
3761 # If frame messages are on ...
3763 $frame & 4 # Extended frame entry message
3765 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3767 # Why -1? But it works! :-(
3768 # Because print_trace will call add 1 to it and then call
3769 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3771 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3773 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3775 # standard frame entry message
3779 # Pop the single-step value back off the stack.
3780 $single |= $stack[ $stack_depth-- ];
3782 # call the original lvalue sub.
3786 # Abstracting common code from multiple places elsewhere:
3787 sub depth_print_lineinfo {
3788 my $always_print = shift;
3790 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth);
3793 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
3795 In Perl 5.8.0, there was a major realignment of the commands and what they did,
3796 Most of the changes were to systematize the command structure and to eliminate
3797 commands that threw away user input without checking.
3799 The following sections describe the code added to make it easy to support
3800 multiple command sets with conflicting command names. This section is a start
3801 at unifying all command processing to make it simpler to develop commands.
3803 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
3804 number, and C<$dbline> (the current line) as arguments.
3806 Support functions in this section which have multiple modes of failure C<die>
3807 on error; the rest simply return a false value.
3809 The user-interface functions (all of the C<cmd_*> functions) just output
3814 The C<%set> hash defines the mapping from command letter to subroutine
3817 C<%set> is a two-level hash, indexed by set name and then by command name.
3818 Note that trying to set the CommandSet to C<foobar> simply results in the
3819 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
3828 'A' => 'pre580_null',
3830 'B' => 'pre580_null',
3831 'd' => 'pre580_null',
3834 'M' => 'pre580_null',
3836 'o' => 'pre580_null',
3842 '<' => 'pre590_prepost',
3843 '<<' => 'pre590_prepost',
3844 '>' => 'pre590_prepost',
3845 '>>' => 'pre590_prepost',
3846 '{' => 'pre590_prepost',
3847 '{{' => 'pre590_prepost',
3851 my %breakpoints_data;
3853 sub _has_breakpoint_data_ref {
3854 my ($filename, $line) = @_;
3857 exists( $breakpoints_data{$filename} )
3859 exists( $breakpoints_data{$filename}{$line} )
3863 sub _get_breakpoint_data_ref {
3864 my ($filename, $line) = @_;
3866 return ($breakpoints_data{$filename}{$line} ||= +{});
3869 sub _delete_breakpoint_data_ref {
3870 my ($filename, $line) = @_;
3872 delete($breakpoints_data{$filename}{$line});
3873 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) {
3874 delete($breakpoints_data{$filename});
3880 sub _set_breakpoint_enabled_status {
3881 my ($filename, $line, $status) = @_;
3883 _get_breakpoint_data_ref($filename, $line)->{'enabled'} =
3890 sub _enable_breakpoint_temp_enabled_status {
3891 my ($filename, $line) = @_;
3893 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1;
3898 sub _cancel_breakpoint_temp_enabled_status {
3899 my ($filename, $line) = @_;
3901 my $ref = _get_breakpoint_data_ref($filename, $line);
3903 delete ($ref->{'temp_enabled'});
3906 _delete_breakpoint_data_ref($filename, $line);
3912 sub _is_breakpoint_enabled {
3913 my ($filename, $line) = @_;
3915 my $data_ref = _get_breakpoint_data_ref($filename, $line);
3916 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'});
3919 =head2 C<cmd_wrapper()> (API)
3921 C<cmd_wrapper()> allows the debugger to switch command sets
3922 depending on the value of the C<CommandSet> option.
3924 It tries to look up the command in the C<%set> package-level I<lexical>
3925 (which means external entities can't fiddle with it) and create the name of
3926 the sub to call based on the value found in the hash (if it's there). I<All>
3927 of the commands to be handled in a set have to be added to C<%set>; if they
3928 aren't found, the 5.8.0 equivalent is called (if there is one).
3930 This code uses symbolic references.
3937 my $dblineno = shift;
3939 # Assemble the command subroutine's name by looking up the
3940 # command set and command name in %set. If we can't find it,
3941 # default to the older version of the command.
3943 . ( $set{$CommandSet}{$cmd}
3944 || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) );
3946 # Call the command subroutine, call it by name.
3947 return __PACKAGE__->can($call)->( $cmd, $line, $dblineno );
3948 } ## end sub cmd_wrapper
3950 =head3 C<cmd_a> (command)
3952 The C<a> command handles pre-execution actions. These are associated with a
3953 particular line, so they're stored in C<%dbline>. We default to the current
3954 line if none is specified.
3960 my $line = shift || ''; # [.|line] expr
3963 # If it's dot (here), or not all digits, use the current line.
3964 $line =~ s/^(\.|(?:[^\d]))/$dbline/;
3966 # Should be a line number followed by an expression.
3967 if ( $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
3968 my ( $lineno, $expr ) = ( $1, $2 );
3970 # If we have an expression ...
3971 if ( length $expr ) {
3973 # ... but the line isn't breakable, complain.
3974 if ( $dbline[$lineno] == 0 ) {
3976 "Line $lineno($dbline[$lineno]) does not have an action?\n";
3980 # It's executable. Record that the line has an action.
3981 $had_breakpoints{$filename} |= 2;
3983 # Remove any action, temp breakpoint, etc.
3984 $dbline{$lineno} =~ s/\0[^\0]*//;
3986 # Add the action to the line.
3987 $dbline{$lineno} .= "\0" . action($expr);
3989 } ## end if (length $expr)
3990 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
3995 "Adding an action requires an optional lineno and an expression\n"
4000 =head3 C<cmd_A> (command)
4002 Delete actions. Similar to above, except the delete code is in a separate
4003 subroutine, C<delete_action>.
4009 my $line = shift || '';
4013 $line =~ s/^\./$dbline/;
4015 # Call delete_action with a null param to delete them all.
4016 # The '1' forces the eval to be true. It'll be false only
4017 # if delete_action blows up for some reason, in which case
4018 # we print $@ and get out.
4019 if ( $line eq '*' ) {
4020 eval { &delete_action(); 1 } or print $OUT $@ and return;
4023 # There's a real line number. Pass it to delete_action.
4024 # Error trapping is as above.
4025 elsif ( $line =~ /^(\S.*)/ ) {
4026 eval { &delete_action($1); 1 } or print $OUT $@ and return;
4029 # Swing and a miss. Bad syntax.
4032 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4036 =head3 C<delete_action> (API)
4038 C<delete_action> accepts either a line number or C<undef>. If a line number
4039 is specified, we check for the line being executable (if it's not, it
4040 couldn't have had an action). If it is, we just take the action off (this
4041 will get any kind of an action, including breakpoints).
4047 if ( defined($i) ) {
4050 die "Line $i has no action .\n" if $dbline[$i] == 0;
4052 # Nuke whatever's there.
4053 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4054 delete $dbline{$i} if $dbline{$i} eq '';
4057 print $OUT "Deleting all actions...\n";
4058 for my $file ( keys %had_breakpoints ) {
4059 local *dbline = $main::{ '_<' . $file };
4062 for ( $i = 1 ; $i <= $max ; $i++ ) {
4063 if ( defined $dbline{$i} ) {
4064 $dbline{$i} =~ s/\0[^\0]*//;
4065 delete $dbline{$i} if $dbline{$i} eq '';
4067 unless ( $had_breakpoints{$file} &= ~2 ) {
4068 delete $had_breakpoints{$file};
4070 } ## end for ($i = 1 ; $i <= $max...
4071 } ## end for my $file (keys %had_breakpoints)
4072 } ## end else [ if (defined($i))
4073 } ## end sub delete_action
4075 =head3 C<cmd_b> (command)
4077 Set breakpoints. Since breakpoints can be set in so many places, in so many
4078 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4079 we try to parse the command type, and then shuttle it off to an appropriate
4080 subroutine to actually do the work of setting the breakpoint in the right
4087 my $line = shift; # [.|line] [cond]
4090 # Make . the current line number if it's there..
4091 $line =~ s/^\.(\s|\z)/$dbline$1/;
4093 # No line number, no condition. Simple break on current line.
4094 if ( $line =~ /^\s*$/ ) {
4095 &cmd_b_line( $dbline, 1 );
4098 # Break on load for a file.
4099 elsif ( $line =~ /^load\b\s*(.*)/ ) {
4105 # b compile|postpone <some sub> [<condition>]
4106 # The interpreter actually traps this one for us; we just put the
4107 # necessary condition in the %postponed hash.
4108 elsif ( $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4110 # Capture the condition if there is one. Make it true if none.
4111 my $cond = length $3 ? $3 : '1';
4113 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
4114 # if it was 'compile'.
4115 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
4117 # De-Perl4-ify the name - ' separators to ::.
4118 $subname =~ s/\'/::/g;
4120 # Qualify it into the current package unless it's already qualified.
4121 $subname = "${package}::" . $subname unless $subname =~ /::/;
4123 # Add main if it starts with ::.
4124 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4126 # Save the break type for this sub.
4127 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
4128 } ## end elsif ($line =~ ...
4129 # b <filename>:<line> [<condition>]
4130 elsif ($line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) {
4131 my ($filename, $line_num, $cond) = ($1, $2, $3);
4132 cmd_b_filename_line(
4135 (length($cond) ? $cond : '1'),
4138 # b <sub name> [<condition>]
4139 elsif ( $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4143 my $cond = length $2 ? $2 : '1';
4144 &cmd_b_sub( $subname, $cond );
4147 # b <line> [<condition>].
4148 elsif ( $line =~ /^(\d*)\s*(.*)/ ) {
4150 # Capture the line. If none, it's the current line.
4151 $line = $1 || $dbline;
4153 # If there's no condition, make it '1'.
4154 my $cond = length $2 ? $2 : '1';
4157 &cmd_b_line( $line, $cond );
4160 # Line didn't make sense.
4162 print "confused by line($line)?\n";
4166 =head3 C<break_on_load> (API)
4168 We want to break when this file is loaded. Mark this file in the
4169 C<%break_on_load> hash, and note that it has a breakpoint in
4170 C<%had_breakpoints>.
4176 $break_on_load{$file} = 1;
4177 $had_breakpoints{$file} |= 1;
4180 =head3 C<report_break_on_load> (API)
4182 Gives us an array of filenames that are set to break on load. Note that
4183 only files with break-on-load are in here, so simply showing the keys
4188 sub report_break_on_load {
4189 sort keys %break_on_load;
4192 =head3 C<cmd_b_load> (command)
4194 We take the file passed in and try to find it in C<%INC> (which maps modules
4195 to files they came from). We mark those files for break-on-load via
4196 C<break_on_load> and then report that it was done.
4204 # This is a block because that way we can use a redo inside it
4205 # even without there being any looping structure at all outside it.
4208 # Save short name and full path if found.
4210 push @files, $::INC{$file} if $::INC{$file};
4212 # Tack on .pm and do it again unless there was a '.' in the name
4214 $file .= '.pm', redo unless $file =~ /\./;
4217 # Do the real work here.
4218 break_on_load($_) for @files;
4220 # All the files that have break-on-load breakpoints.
4221 @files = report_break_on_load;
4223 # Normalize for the purposes of our printing this.
4226 print $OUT "Will stop on load of '@files'.\n";
4227 } ## end sub cmd_b_load
4229 =head3 C<$filename_error> (API package global)
4231 Several of the functions we need to implement in the API need to work both
4232 on the current file and on other files. We don't want to duplicate code, so
4233 C<$filename_error> is used to contain the name of the file that's being
4234 worked on (if it's not the current one).
4236 We can now build functions in pairs: the basic function works on the current
4237 file, and uses C<$filename_error> as part of its error message. Since this is
4238 initialized to C<"">, no filename will appear when we are working on the
4241 The second function is a wrapper which does the following:
4247 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4251 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4255 Calls the first function.
4257 The first function works on the I<current> file (i.e., the one we changed to),
4258 and prints C<$filename_error> in the error message (the name of the other file)
4259 if it needs to. When the functions return, C<*dbline> is restored to point
4260 to the actual current file (the one we're executing in) and
4261 C<$filename_error> is restored to C<"">. This restores everything to
4262 the way it was before the second function was called at all.
4264 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4271 use vars qw($filename_error);
4272 $filename_error = '';
4274 =head3 breakable_line(from, to) (API)
4276 The subroutine decides whether or not a line in the current file is breakable.
4277 It walks through C<@dbline> within the range of lines specified, looking for
4278 the first line that is breakable.
4280 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4281 first line I<after> C<$to> that's breakable, if there is one.
4283 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4284 first line I<before> C<$to> that's breakable, if there is one.
4288 sub breakable_line {
4290 my ( $from, $to ) = @_;
4292 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4295 # If there are at least 2 arguments, we're trying to search a range.
4298 # $delta is positive for a forward search, negative for a backward one.
4299 my $delta = $from < $to ? +1 : -1;
4301 # Keep us from running off the ends of the file.
4302 my $limit = $delta > 0 ? $#dbline : 1;
4304 # Clever test. If you're a mathematician, it's obvious why this
4305 # test works. If not:
4306 # If $delta is positive (going forward), $limit will be $#dbline.
4307 # If $to is less than $limit, ($limit - $to) will be positive, times
4308 # $delta of 1 (positive), so the result is > 0 and we should use $to
4309 # as the stopping point.
4311 # If $to is greater than $limit, ($limit - $to) is negative,
4312 # times $delta of 1 (positive), so the result is < 0 and we should
4313 # use $limit ($#dbline) as the stopping point.
4315 # If $delta is negative (going backward), $limit will be 1.
4316 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4317 # (negative) so the result is > 0, and we use $to as the stopping
4320 # If $to is less than zero, ($limit - $to) will be positive,
4321 # times $delta of -1 (negative), so the result is not > 0, and
4322 # we use $limit (1) as the stopping point.
4324 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4325 # (negative), still giving zero; the result is not > 0, and
4326 # we use $limit (1) as the stopping point.
4328 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4329 # (negative), giving a positive (>0) value, so we'll set $limit to
4332 $limit = $to if ( $limit - $to ) * $delta > 0;
4334 # The real search loop.
4335 # $i starts at $from (the point we want to start searching from).
4336 # We move through @dbline in the appropriate direction (determined
4337 # by $delta: either -1 (back) or +1 (ahead).
4338 # We stay in as long as we haven't hit an executable line
4339 # ($dbline[$i] == 0 means not executable) and we haven't reached
4340 # the limit yet (test similar to the above).
4341 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4343 } ## end if (@_ >= 2)
4345 # If $i points to a line that is executable, return that.
4346 return $i unless $dbline[$i] == 0;
4348 # Format the message and print it: no breakable lines in range.
4349 my ( $pl, $upto ) = ( '', '' );
4350 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4352 # If there's a filename in filename_error, we'll see it.
4354 die "Line$pl $from$upto$filename_error not breakable\n";
4355 } ## end sub breakable_line
4357 =head3 breakable_line_in_filename(file, from, to) (API)
4359 Like C<breakable_line>, but look in another file.
4363 sub breakable_line_in_filename {
4365 # Capture the file name.
4368 # Swap the magic line array over there temporarily.
4369 local *dbline = $main::{ '_<' . $f };
4371 # If there's an error, it's in this other file.
4372 local $filename_error = " of '$f'";
4374 # Find the breakable line.
4377 # *dbline and $filename_error get restored when this block ends.
4379 } ## end sub breakable_line_in_filename
4381 =head3 break_on_line(lineno, [condition]) (API)
4383 Adds a breakpoint with the specified condition (or 1 if no condition was
4384 specified) to the specified line. Dies if it can't.
4389 my ( $i, $cond ) = @_;
4391 # Always true if no condition supplied.
4392 $cond = 1 unless @_ >= 2;
4398 # Woops, not a breakable line. $filename_error allows us to say
4399 # if it was in a different file.
4400 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4402 # Mark this file as having breakpoints in it.
4403 $had_breakpoints{$filename} |= 1;
4405 # If there is an action or condition here already ...
4406 if ( $dbline{$i} ) {
4408 # ... swap this condition for the existing one.
4409 $dbline{$i} =~ s/^[^\0]*/$cond/;
4413 # Nothing here - just add the condition.
4414 $dbline{$i} = $cond;
4416 _set_breakpoint_enabled_status($filename, $i, 1);
4418 } ## end sub break_on_line
4420 =head3 cmd_b_line(line, [condition]) (command)
4422 Wrapper for C<break_on_line>. Prints the failure message if it
4428 eval { break_on_line(@_); 1 } or do {
4430 print $OUT $@ and return;
4432 } ## end sub cmd_b_line
4434 =head3 cmd_b_filename_line(line, [condition]) (command)
4436 Wrapper for C<break_on_filename_line>. Prints the failure message if it
4441 sub cmd_b_filename_line {
4442 eval { break_on_filename_line(@_); 1 } or do {
4444 print $OUT $@ and return;
4448 =head3 break_on_filename_line(file, line, [condition]) (API)
4450 Switches to the file specified and then calls C<break_on_line> to set
4455 sub break_on_filename_line {
4456 my ( $f, $i, $cond ) = @_;
4458 # Always true if condition left off.
4459 $cond = 1 unless @_ >= 3;
4461 # Switch the magical hash temporarily.
4462 local *dbline = $main::{ '_<' . $f };
4464 # Localize the variables that break_on_line uses to make its message.
4465 local $filename_error = " of '$f'";
4466 local $filename = $f;
4468 # Add the breakpoint.
4469 break_on_line( $i, $cond );
4470 } ## end sub break_on_filename_line
4472 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4474 Switch to another file, search the range of lines specified for an
4475 executable one, and put a breakpoint on the first one you find.
4479 sub break_on_filename_line_range {
4480 my ( $f, $from, $to, $cond ) = @_;
4482 # Find a breakable line if there is one.
4483 my $i = breakable_line_in_filename( $f, $from, $to );
4485 # Always true if missing.
4486 $cond = 1 unless @_ >= 3;
4488 # Add the breakpoint.
4489 break_on_filename_line( $f, $i, $cond );
4490 } ## end sub break_on_filename_line_range
4492 =head3 subroutine_filename_lines(subname, [condition]) (API)
4494 Search for a subroutine within a given file. The condition is ignored.
4495 Uses C<find_sub> to locate the desired subroutine.
4499 sub subroutine_filename_lines {
4500 my ( $subname, $cond ) = @_;
4502 # Returned value from find_sub() is fullpathname:startline-endline.
4503 # The match creates the list (fullpathname, start, end). Falling off
4504 # the end of the subroutine returns this implicitly.
4505 find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/;
4506 } ## end sub subroutine_filename_lines
4508 =head3 break_subroutine(subname) (API)
4510 Places a break on the first line possible in the specified subroutine. Uses
4511 C<subroutine_filename_lines> to find the subroutine, and
4512 C<break_on_filename_line_range> to place the break.
4516 sub break_subroutine {
4517 my $subname = shift;
4519 # Get filename, start, and end.
4520 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
4521 or die "Subroutine $subname not found.\n";
4524 # Null condition changes to '1' (always true).
4525 my $cond = @_ ? shift(@_) : 1;
4527 # Put a break the first place possible in the range of lines
4528 # that make up this subroutine.
4529 break_on_filename_line_range( $file, $s, $e, $cond );
4530 } ## end sub break_subroutine
4532 =head3 cmd_b_sub(subname, [condition]) (command)
4534 We take the incoming subroutine name and fully-qualify it as best we can.
4538 =item 1. If it's already fully-qualified, leave it alone.
4540 =item 2. Try putting it in the current package.
4542 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
4544 =item 4. If it starts with '::', put it in 'main::'.
4548 After all this cleanup, we call C<break_subroutine> to try to set the
4554 my ( $subname, $cond ) = @_;
4556 # Add always-true condition if we have none.
4557 $cond = 1 unless @_ >= 2;
4559 # If the subname isn't a code reference, qualify it so that
4560 # break_subroutine() will work right.
4561 unless ( ref $subname eq 'CODE' ) {
4564 $subname =~ s/\'/::/g;
4567 # Put it in this package unless it's already qualified.
4568 $subname = "${package}::" . $subname
4569 unless $subname =~ /::/;
4571 # Requalify it into CORE::GLOBAL if qualifying it into this
4572 # package resulted in its not being defined, but only do so
4573 # if it really is in CORE::GLOBAL.
4574 $subname = "CORE::GLOBAL::$s"
4575 if not defined &$subname
4577 and defined &{"CORE::GLOBAL::$s"};
4579 # Put it in package 'main' if it has a leading ::.
4580 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4582 } ## end unless (ref $subname eq 'CODE')
4584 # Try to set the breakpoint.
4585 eval { break_subroutine( $subname, $cond ); 1 } or do {
4587 print $OUT $@ and return;
4589 } ## end sub cmd_b_sub
4591 =head3 C<cmd_B> - delete breakpoint(s) (command)
4593 The command mostly parses the command line and tries to turn the argument
4594 into a line spec. If it can't, it uses the current line. It then calls
4595 C<delete_breakpoint> to actually do the work.
4597 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
4598 thereby deleting all the breakpoints.
4605 # No line spec? Use dbline.
4606 # If there is one, use it if it's non-zero, or wipe it out if it is.
4607 my $line = ( $_[0] =~ /^\./ ) ? $dbline : shift || '';
4610 # If the line was dot, make the line the current one.
4611 $line =~ s/^\./$dbline/;
4613 # If it's * we're deleting all the breakpoints.
4614 if ( $line eq '*' ) {
4615 eval { &delete_breakpoint(); 1 } or print $OUT $@ and return;
4618 # If there is a line spec, delete the breakpoint on that line.
4619 elsif ( $line =~ /^(\S.*)/ ) {
4620 eval { &delete_breakpoint( $line || $dbline ); 1 } or do {
4622 print $OUT $@ and return;
4624 } ## end elsif ($line =~ /^(\S.*)/)
4629 "Deleting a breakpoint requires a line number, or '*' for all\n"
4634 =head3 delete_breakpoint([line]) (API)
4636 This actually does the work of deleting either a single breakpoint, or all
4639 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
4640 just drop out with a message saying so. If it is, we remove the condition
4641 part of the 'condition\0action' that says there's a breakpoint here. If,
4642 after we've done that, there's nothing left, we delete the corresponding
4643 line in C<%dbline> to signal that no action needs to be taken for this line.
4645 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
4646 which lists all currently-loaded files which have breakpoints. We then look
4647 at each line in each of these files, temporarily switching the C<%dbline>
4648 and C<@dbline> structures to point to the files in question, and do what
4649 we did in the single line case: delete the condition in C<@dbline>, and
4650 delete the key in C<%dbline> if nothing's left.
4652 We then wholesale delete C<%postponed>, C<%postponed_file>, and
4653 C<%break_on_load>, because these structures contain breakpoints for files
4654 and code that haven't been loaded yet. We can just kill these off because there
4655 are no magical debugger structures associated with them.
4659 sub delete_breakpoint {
4664 # If we got a line, delete just that one.
4665 if ( defined($i) ) {
4667 # Woops. This line wasn't breakable at all.
4668 die "Line $i not breakable.\n" if $dbline[$i] == 0;
4670 # Kill the condition, but leave any action.
4671 $dbline{$i} =~ s/^[^\0]*//;
4673 # Remove the entry entirely if there's no action left.
4674 if ($dbline{$i} eq '') {
4676 _delete_breakpoint_data_ref($fn, $i);
4680 # No line; delete them all.
4682 print $OUT "Deleting all breakpoints...\n";
4684 # %had_breakpoints lists every file that had at least one
4686 for my $file ( keys %had_breakpoints ) {
4688 # Switch to the desired file temporarily.
4689 local *dbline = $main::{ '_<' . $file };
4694 # For all lines in this file ...
4695 for ( $i = 1 ; $i <= $max ; $i++ ) {
4697 # If there's a breakpoint or action on this line ...
4698 if ( defined $dbline{$i} ) {
4700 # ... remove the breakpoint.
4701 $dbline{$i} =~ s/^[^\0]+//;
4702 if ( $dbline{$i} =~ s/^\0?$// ) {
4704 # Remove the entry altogether if no action is there.
4706 _delete_breakpoint_data_ref($file, $i);
4708 } ## end if (defined $dbline{$i...
4709 } ## end for ($i = 1 ; $i <= $max...
4711 # If, after we turn off the "there were breakpoints in this file"
4712 # bit, the entry in %had_breakpoints for this file is zero,
4713 # we should remove this file from the hash.
4714 if ( not $had_breakpoints{$file} &= ~1 ) {
4715 delete $had_breakpoints{$file};
4717 } ## end for my $file (keys %had_breakpoints)
4719 # Kill off all the other breakpoints that are waiting for files that
4720 # haven't been loaded yet.
4722 undef %postponed_file;
4723 undef %break_on_load;
4724 } ## end else [ if (defined($i))
4725 } ## end sub delete_breakpoint
4727 =head3 cmd_stop (command)
4729 This is meant to be part of the new command API, but it isn't called or used
4730 anywhere else in the debugger. XXX It is probably meant for use in development
4735 sub cmd_stop { # As on ^C, but not signal-safy.
4739 =head3 C<cmd_e> - threads
4741 Display the current thread id:
4745 This could be how (when implemented) to send commands to this thread id (e cmd)
4746 or that thread id (e tid cmd).
4753 unless (exists($INC{'threads.pm'})) {
4754 print "threads not loaded($ENV{PERL5DB_THREADED})
4755 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4757 my $tid = threads->tid;
4758 print "thread id: $tid\n";
4762 =head3 C<cmd_E> - list of thread ids
4764 Display the list of available thread ids:
4768 This could be used (when implemented) to send commands to all threads (E cmd).
4775 unless (exists($INC{'threads.pm'})) {
4776 print "threads not loaded($ENV{PERL5DB_THREADED})
4777 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4779 my $tid = threads->tid;
4780 print "thread ids: ".join(', ',
4781 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
4786 =head3 C<cmd_h> - help command (command)
4788 Does the work of either
4794 Showing all the debugger help
4798 Showing help for a specific command
4805 use vars qw($summary);
4810 # If we have no operand, assume null.
4811 my $line = shift || '';
4813 # 'h h'. Print the long-format help.
4814 if ( $line =~ /^h\s*/ ) {
4818 # 'h <something>'. Search for the command and print only its help.
4819 elsif ( $line =~ /^(\S.*)$/ ) {
4821 # support long commands; otherwise bogus errors
4822 # happen when you ask for h on <CR> for example
4823 my $asked = $1; # the command requested
4824 # (for proper error message)
4826 my $qasked = quotemeta($asked); # for searching; we don't
4827 # want to use it as a pattern.
4828 # XXX: finds CR but not <CR>
4830 # Search the help string for the command.
4832 $help =~ /^ # Start of a line
4834 (?:[IB]<) # Optional markup
4835 $qasked # The requested command
4840 # It's there; pull it out and print it.
4844 (?:[IB]<) # Optional markup
4845 $qasked # The command
4846 ([\s\S]*?) # Description line(s)
4847 \n) # End of last description line
4848 (?!\s) # Next line not starting with
4857 # Not found; not a debugger command.
4859 print_help("B<$asked> is not a debugger command.\n");
4861 } ## end elsif ($line =~ /^(\S.*)$/)
4863 # 'h' - print the summary help.
4865 print_help($summary);
4869 =head3 C<cmd_i> - inheritance display
4871 Display the (nested) parentage of the module or object given.
4878 foreach my $isa ( split( /\s+/, $line ) ) {
4887 defined( ${"$_\::VERSION"} )
4888 ? ' ' . ${"$_\::VERSION"}
4890 } @{mro::get_linear_isa(ref($isa) || $isa)}
4896 =head3 C<cmd_l> - list lines (command)
4898 Most of the command is taken up with transforming all the different line
4899 specification syntaxes into 'start-stop'. After that is done, the command
4900 runs a loop over C<@dbline> for the specified range of lines. It handles
4901 the printing of each line and any markers (C<==E<gt>> for current line,
4902 C<b> for break on this line, C<a> for action on this line, C<:> for this
4905 We save the last line listed in the C<$start> global for further listing
4911 my $current_line = $line;
4915 # If this is '-something', delete any spaces after the dash.
4916 $line =~ s/^-\s*$/-/;
4918 # If the line is '$something', assume this is a scalar containing a
4920 if ( $line =~ /^(\$.*)/s ) {
4922 # Set up for DB::eval() - evaluate in *user* context.
4927 # Ooops. Bad scalar.
4928 print( $OUT "Error: $@\n" ), next CMD if $@;
4930 # Good scalar. If it's a reference, find what it points to.
4932 print( $OUT "Interpreted as: $1 $s\n" );
4935 # Call self recursively to really do the command.
4937 } ## end if ($line =~ /^(\$.*)/s)
4939 # l name. Try to find a sub by that name.
4940 elsif ( $line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s ) {
4941 my $s = $subname = $1;
4944 $subname =~ s/\'/::/;
4946 # Put it in this package unless it starts with ::.
4947 $subname = $package . "::" . $subname unless $subname =~ /::/;
4949 # Put it in CORE::GLOBAL if t doesn't start with :: and
4950 # it doesn't live in this package and it lives in CORE::GLOBAL.
4951 $subname = "CORE::GLOBAL::$s"
4952 if not defined &$subname
4954 and defined &{"CORE::GLOBAL::$s"};
4956 # Put leading '::' names into 'main::'.
4957 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4959 # Get name:start-stop from find_sub, and break this up at
4961 my @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
4963 # Pull off start-stop.
4964 my $subrange = pop @pieces;
4966 # If the name contained colons, the split broke it up.
4967 # Put it back together.
4968 $file = join( ':', @pieces );
4970 # If we're not in that file, switch over to it.
4971 if ( $file ne $filename ) {
4972 print $OUT "Switching to file '$file'.\n"
4973 unless $slave_editor;
4975 # Switch debugger's magic structures.
4976 *dbline = $main::{ '_<' . $file };
4979 } ## end if ($file ne $filename)
4981 # Subrange is 'start-stop'. If this is less than a window full,
4982 # swap it to 'start+', which will list a window from the start point.
4984 if ( eval($subrange) < -$window ) {
4985 $subrange =~ s/-.*/+/;
4988 # Call self recursively to list the range.
4990 &cmd_l( 'l', $subrange );
4991 } ## end if ($subrange)
4995 print $OUT "Subroutine $subname not found.\n";
4997 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
5000 elsif ( $line =~ /^\s*$/ ) {
5002 # Compute new range to list.
5003 $incr = $window - 1;
5004 $line = $start . '-' . ( $start + $incr );
5007 &cmd_l( 'l', $line );
5010 # l [start]+number_of_lines
5011 elsif ( $line =~ /^(\d*)\+(\d*)$/ ) {
5013 # Don't reset start for 'l +nnn'.
5016 # Increment for list. Use window size if not specified.
5017 # (Allows 'l +' to work.)
5019 $incr = $window - 1 unless $incr;
5021 # Create a line range we'll understand, and recurse to do it.
5022 $line = $start . '-' . ( $start + $incr );
5023 &cmd_l( 'l', $line );
5024 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
5026 # l start-stop or l start,stop
5027 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) {
5029 # Determine end point; use end of file if not specified.
5030 my $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 );
5032 # Go on to the end, and then stop.
5033 $end = $max if $end > $max;
5035 # Determine start line.
5037 $i = $line if $i eq '.';
5041 # If we're running under a slave editor, force it to show the lines.
5042 if ($slave_editor) {
5043 print $OUT "\032\032$filename:$i:0\n";
5047 # We're doing it ourselves. We want to show the line and special
5049 # - the current line in execution
5050 # - whether a line is breakable or not
5051 # - whether a line has a break or not
5052 # - whether a line has an action or not
5054 for ( ; $i <= $end ; $i++ ) {
5056 # Check for breakpoints and actions.
5057 my ( $stop, $action );
5058 ( $stop, $action ) = split( /\0/, $dbline{$i} )
5061 # ==> if this is the current line in execution,
5062 # : if it's breakable.
5064 ( $i == $current_line and $filename eq $filename_ini )
5066 : ( $dbline[$i] + 0 ? ':' : ' ' );
5068 # Add break and action indicators.
5069 $arrow .= 'b' if $stop;
5070 $arrow .= 'a' if $action;
5073 print $OUT "$i$arrow\t", $dbline[$i];
5075 # Move on to the next line. Drop out on an interrupt.
5076 $i++, last if $signal;
5077 } ## end for (; $i <= $end ; $i++)
5079 # Line the prompt up; print a newline if the last line listed
5080 # didn't have a newline.
5081 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/;
5082 } ## end else [ if ($slave_editor)
5084 # Save the point we last listed to in case another relative 'l'
5085 # command is desired. Don't let it run off the end.
5087 $start = $max if $start > $max;
5088 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
5091 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5093 To list breakpoints, the command has to look determine where all of them are
5094 first. It starts a C<%had_breakpoints>, which tells us what all files have
5095 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5096 magic source and breakpoint data structures) to the file, and then look
5097 through C<%dbline> for lines with breakpoints and/or actions, listing them
5098 out. We look through C<%postponed> not-yet-compiled subroutines that have
5099 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5100 that have breakpoints.
5102 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5109 # If no argument, list everything. Pre-5.8.0 version always lists
5111 my $arg = shift || 'abw';
5112 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
5114 # See what is wanted.
5115 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0;
5116 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0;
5117 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0;
5119 # Breaks and actions are found together, so we look in the same place
5121 if ( $break_wanted or $action_wanted ) {
5123 # Look in all the files with breakpoints...
5124 for my $file ( keys %had_breakpoints ) {
5126 # Temporary switch to this file.
5127 local *dbline = $main::{ '_<' . $file };
5129 # Set up to look through the whole file.
5131 my $was; # Flag: did we print something
5134 # For each line in the file ...
5135 for ( my $i = 1 ; $i <= $max ; $i++ ) {
5137 # We've got something on this line.
5138 if ( defined $dbline{$i} ) {
5140 # Print the header if we haven't.
5141 print $OUT "$file:\n" unless $was++;
5144 print $OUT " $i:\t", $dbline[$i];
5146 # Pull out the condition and the action.
5147 my ( $stop, $action ) = split( /\0/, $dbline{$i} );
5149 # Print the break if there is one and it's wanted.
5150 print $OUT " break if (", $stop, ")\n"
5154 # Print the action if there is one and it's wanted.
5155 print $OUT " action: ", $action, "\n"
5159 # Quit if the user hit interrupt.
5161 } ## end if (defined $dbline{$i...
5162 } ## end for ($i = 1 ; $i <= $max...
5163 } ## end for my $file (keys %had_breakpoints)
5164 } ## end if ($break_wanted or $action_wanted)
5166 # Look for breaks in not-yet-compiled subs:
5167 if ( %postponed and $break_wanted ) {
5168 print $OUT "Postponed breakpoints in subroutines:\n";
5170 for $subname ( keys %postponed ) {
5171 print $OUT " $subname\t$postponed{$subname}\n";
5174 } ## end if (%postponed and $break_wanted)
5176 # Find files that have not-yet-loaded breaks:
5177 my @have = map { # Combined keys
5178 keys %{ $postponed_file{$_} }
5179 } keys %postponed_file;
5181 # If there are any, list them.
5182 if ( @have and ( $break_wanted or $action_wanted ) ) {
5183 print $OUT "Postponed breakpoints in files:\n";
5184 my ( $file, $line );
5186 for $file ( keys %postponed_file ) {
5187 my $db = $postponed_file{$file};
5188 print $OUT " $file:\n";
5189 for $line ( sort { $a <=> $b } keys %$db ) {
5190 print $OUT " $line:\n";
5191 my ( $stop, $action ) = split( /\0/, $$db{$line} );
5192 print $OUT " break if (", $stop, ")\n"
5195 print $OUT " action: ", $action, "\n"
5199 } ## end for $line (sort { $a <=>...
5201 } ## end for $file (keys %postponed_file)
5202 } ## end if (@have and ($break_wanted...
5203 if ( %break_on_load and $break_wanted ) {
5204 print $OUT "Breakpoints on load:\n";
5206 for $file ( keys %break_on_load ) {
5207 print $OUT " $file\n";
5210 } ## end if (%break_on_load and...
5211 if ($watch_wanted) {
5213 print $OUT "Watch-expressions:\n" if @to_watch;
5214 for my $expr (@to_watch) {
5215 print $OUT " $expr\n";
5218 } ## end if ($trace & 2)
5219 } ## end if ($watch_wanted)
5222 =head3 C<cmd_M> - list modules (command)
5224 Just call C<list_modules>.
5232 =head3 C<cmd_o> - options (command)
5234 If this is just C<o> by itself, we list the current settings via
5235 C<dump_option>. If there's a nonblank value following it, we pass that on to
5236 C<parse_options> for processing.
5242 my $opt = shift || ''; # opt[=val]
5244 # Nonblank. Try to parse and process.
5245 if ( $opt =~ /^(\S.*)/ ) {
5249 # Blank. List the current option settings.
5257 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5259 Advises the user that the O command has been renamed.
5264 print $OUT "The old O command is now the o command.\n"; # hint
5265 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5266 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5269 =head3 C<cmd_v> - view window (command)
5271 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5272 move back a few lines to list the selected line in context. Uses C<cmd_l>
5273 to do the actual listing after figuring out the range of line to request.
5277 use vars qw($preview);
5283 # Extract the line to list around. (Astute readers will have noted that
5284 # this pattern will match whether or not a numeric line is specified,
5285 # which means that we'll always enter this loop (though a non-numeric
5286 # argument results in no action at all)).
5287 if ( $line =~ /^(\d*)$/ ) {
5289 # Total number of lines to list (a windowful).
5290 $incr = $window - 1;
5292 # Set the start to the argument given (if there was one).
5295 # Back up by the context amount.
5298 # Put together a linespec that cmd_l will like.
5299 $line = $start . '-' . ( $start + $incr );
5302 &cmd_l( 'l', $line );
5303 } ## end if ($line =~ /^(\d*)$/)
5306 =head3 C<cmd_w> - add a watch expression (command)
5308 The 5.8 version of this command adds a watch expression if one is specified;
5309 it does nothing if entered with no operands.
5311 We extract the expression, save it, evaluate it in the user's context, and
5312 save the value. We'll re-evaluate it each time the debugger passes a line,
5313 and will stop (see the code at the top of the command loop) if the value
5314 of any of the expressions changes.
5321 # Null expression if no arguments.
5322 my $expr = shift || '';
5324 # If expression is not null ...
5325 if ( $expr =~ /^(\S.*)/ ) {
5328 push @to_watch, $expr;
5330 # Parameterize DB::eval and call it to get the expression's value
5331 # in the user's context. This version can handle expressions which
5332 # return a list value.
5334 my ($val) = join( ' ', &eval );
5335 $val = ( defined $val ) ? "'$val'" : 'undef';
5337 # Save the current value of the expression.
5338 push @old_watch, $val;
5340 # We are now watching expressions.
5342 } ## end if ($expr =~ /^(\S.*)/)
5344 # You have to give one to get one.
5346 print $OUT "Adding a watch-expression requires an expression\n"; # hint
5350 =head3 C<cmd_W> - delete watch expressions (command)
5352 This command accepts either a watch expression to be removed from the list
5353 of watch expressions, or C<*> to delete them all.
5355 If C<*> is specified, we simply empty the watch expression list and the
5356 watch expression value list. We also turn off the bit that says we've got
5359 If an expression (or partial expression) is specified, we pattern-match
5360 through the expressions and remove the ones that match. We also discard
5361 the corresponding values. If no watch expressions are left, we turn off
5362 the I<watching expressions> bit.
5368 my $expr = shift || '';
5371 if ( $expr eq '*' ) {
5376 print $OUT "Deleting all watch expressions ...\n";
5379 @to_watch = @old_watch = ();
5382 # Delete one of them.
5383 elsif ( $expr =~ /^(\S.*)/ ) {
5385 # Where we are in the list.
5388 # For each expression ...
5389 foreach (@to_watch) {
5390 my $val = $to_watch[$i_cnt];
5392 # Does this one match the command argument?
5393 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
5394 # Yes. Turn it off, and its value too.
5395 splice( @to_watch, $i_cnt, 1 );
5396 splice( @old_watch, $i_cnt, 1 );
5399 } ## end foreach (@to_watch)
5401 # We don't bother to turn watching off because
5402 # a) we don't want to stop calling watchfunction() it it exists
5403 # b) foreach over a null list doesn't do anything anyway
5405 } ## end elsif ($expr =~ /^(\S.*)/)
5407 # No command arguments entered.
5410 "Deleting a watch-expression requires an expression, or '*' for all\n"
5415 ### END of the API section
5417 =head1 SUPPORT ROUTINES
5419 These are general support routines that are used in a number of places
5420 throughout the debugger.
5424 save() saves the user's versions of globals that would mess us up in C<@saved>,
5425 and installs the versions we like better.
5431 # Save eval failure, command failure, extended OS error, output field
5432 # separator, input record separator, output record separator and
5433 # the warning setting.
5434 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
5436 $, = ""; # output field separator is null string
5437 $/ = "\n"; # input record separator is newline
5438 $\ = ""; # output record separator is null string
5439 $^W = 0; # warnings are off
5442 =head2 C<print_lineinfo> - show where we are now
5444 print_lineinfo prints whatever it is that it is handed; it prints it to the
5445 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5446 us to feed line information to a slave editor without messing up the
5451 sub print_lineinfo {
5453 # Make the terminal sensible if we're not the primary debugger.
5454 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5458 } ## end sub print_lineinfo
5460 =head2 C<postponed_sub>
5462 Handles setting postponed breakpoints in subroutines once they're compiled.
5463 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5464 range for the subroutine, then mark the file as having a breakpoint,
5465 temporarily switch the C<*dbline> glob over to the source file, and then
5466 search the given range of lines to find a breakable line. If we find one,
5467 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
5471 # The following takes its argument via $evalarg to preserve current @_
5475 # Get the subroutine name.
5476 my $subname = shift;
5478 # If this is a 'break +<n> if <condition>' ...
5479 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
5481 # If there's no offset, use '+0'.
5482 my $offset = $1 || 0;
5484 # find_sub's value is 'fullpath-filename:start-stop'. It's
5485 # possible that the filename might have colons in it too.
5486 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
5489 # We got the start line. Add the offset '+<n>' from
5490 # $postponed{subname}.
5493 # Switch to the file this sub is in, temporarily.
5494 local *dbline = $main::{ '_<' . $file };
5496 # No warnings, please.
5497 local $^W = 0; # != 0 is magical below
5499 # This file's got a breakpoint in it.
5500 $had_breakpoints{$file} |= 1;
5502 # Last line in file.
5505 # Search forward until we hit a breakable line or get to
5506 # the end of the file.
5507 ++$i until $dbline[$i] != 0 or $i >= $max;
5509 # Copy the breakpoint in and delete it from %postponed.
5510 $dbline{$i} = delete $postponed{$subname};
5513 # find_sub didn't find the sub.
5516 print $OUT "Subroutine $subname not found.\n";
5519 } ## end if ($postponed{$subname...
5520 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
5522 #print $OUT "In postponed_sub for '$subname'.\n";
5523 } ## end sub postponed_sub
5527 Called after each required file is compiled, but before it is executed;
5528 also called if the name of a just-compiled subroutine is a key of
5529 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
5530 etc.) into the just-compiled code.
5532 If this is a C<require>'d file, the incoming parameter is the glob
5533 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
5535 If it's a subroutine, the incoming parameter is the subroutine name.
5541 # If there's a break, process it.
5542 if ($ImmediateStop) {
5544 # Right, we've stopped. Turn it off.
5547 # Enter the command loop when DB::DB gets called.
5551 # If this is a subroutine, let postponed_sub() deal with it.
5552 return &postponed_sub unless ref \$_[0] eq 'GLOB';
5554 # Not a subroutine. Deal with the file.
5555 local *dbline = shift;
5556 my $filename = $dbline;
5557 $filename =~ s/^_<//;
5559 $signal = 1, print $OUT "'$filename' loaded...\n"
5560 if $break_on_load{$filename};
5561 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
5563 # Do we have any breakpoints to put in this file?
5564 return unless $postponed_file{$filename};
5566 # Yes. Mark this file as having breakpoints.
5567 $had_breakpoints{$filename} |= 1;
5569 # "Cannot be done: insufficient magic" - we can't just put the
5570 # breakpoints saved in %postponed_file into %dbline by assigning
5571 # the whole hash; we have to do it one item at a time for the
5572 # breakpoints to be set properly.
5573 #%dbline = %{$postponed_file{$filename}};
5575 # Set the breakpoints, one at a time.
5578 for $key ( keys %{ $postponed_file{$filename} } ) {
5580 # Stash the saved breakpoint into the current file's magic line array.
5581 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
5584 # This file's been compiled; discard the stored breakpoints.
5585 delete $postponed_file{$filename};
5587 } ## end sub postponed
5591 C<dumpit> is the debugger's wrapper around dumpvar.pl.
5593 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
5594 a reference to a variable (the thing to be dumped) as its input.
5596 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
5597 the currently-selected filehandle, thank you very much). The current
5598 values of the package globals C<$single> and C<$trace> are backed up in
5599 lexicals, and they are turned off (this keeps the debugger from trying
5600 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
5601 preserve its current value and it is set to zero to prevent entry/exit
5602 messages from printing, and C<$doret> is localized as well and set to -2 to
5603 prevent return values from being shown.
5605 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
5606 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
5607 installed version in C<@INC>, yours will be used instead. Possible security
5610 It then checks to see if the subroutine C<main::dumpValue> is now defined
5611 (it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
5612 localizes the globals necessary for things to be sane when C<main::dumpValue()>
5613 is called, and picks up the variable to be dumped from the parameter list.
5615 It checks the package global C<%options> to see if there's a C<dumpDepth>
5616 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
5617 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
5618 structure: -1 means dump everything.
5620 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
5623 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
5624 and we then return to the caller.
5630 # Save the current output filehandle and switch to the one
5631 # passed in as the first parameter.
5632 my $savout = select(shift);
5634 # Save current settings of $single and $trace, and then turn them off.
5635 my $osingle = $single;
5636 my $otrace = $trace;
5637 $single = $trace = 0;
5639 # XXX Okay, what do $frame and $doret do, again?
5643 # Load dumpvar.pl unless we've already got the sub we need from it.
5644 unless ( defined &main::dumpValue ) {
5645 do 'dumpvar.pl' or die $@;
5648 # If the load succeeded (or we already had dumpvalue()), go ahead
5650 if ( defined &main::dumpValue ) {
5655 my $maxdepth = shift || $option{dumpDepth};
5656 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
5657 &main::dumpValue( $v, $maxdepth );
5658 } ## end if (defined &main::dumpValue)
5660 # Oops, couldn't load dumpvar.pl.
5663 print $OUT "dumpvar.pl not available.\n";
5666 # Reset $single and $trace to their old values.
5670 # Restore the old filehandle.
5674 =head2 C<print_trace>
5676 C<print_trace>'s job is to print a stack trace. It does this via the
5677 C<dump_trace> routine, which actually does all the ferreting-out of the
5678 stack trace data. C<print_trace> takes care of formatting it nicely and
5679 printing it to the proper filehandle.
5687 The filehandle to print to.
5691 How many frames to skip before starting trace.
5695 How many frames to print.
5699 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
5703 The original comment below seems to be noting that the traceback may not be
5704 correct if this routine is called in a tied method.
5708 # Tied method do not create a context, so may get wrong message:
5714 # If this is going to a slave editor, but we're not the primary
5715 # debugger, reset it first.
5717 if $fh eq $LINEINFO # slave editor
5718 and $LINEINFO eq $OUT # normal output
5719 and $term_pid != $$; # not the primary
5721 # Collect the actual trace information to be formatted.
5722 # This is an array of hashes of subroutine call info.
5723 my @sub = dump_trace( $_[0] + 1, $_[1] );
5725 # Grab the "short report" flag from @_.
5726 my $short = $_[2]; # Print short report, next one for sub name
5728 # Run through the traceback info, format it, and print it.
5730 for ( my $i = 0 ; $i <= $#sub ; $i++ ) {
5732 # Drop out if the user has lost interest and hit control-C.
5735 # Set the separator so arrys print nice.
5738 # Grab and stringify the arguments if they are there.
5740 defined $sub[$i]{args}
5741 ? "(@{ $sub[$i]{args} })"
5744 # Shorten them up if $maxtrace says they're too long.
5745 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
5746 if length $args > $maxtrace;
5748 # Get the file name.
5749 my $file = $sub[$i]{file};
5751 # Put in a filename header if short is off.
5752 $file = $file eq '-e' ? $file : "file '$file'" unless $short;
5754 # Get the actual sub's name, and shorten to $maxtrace's requirement.
5756 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
5758 # Short report uses trimmed file and sub names.
5760 my $sub = @_ >= 4 ? $_[3] : $s;
5761 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
5762 } ## end if ($short)
5764 # Non-short report includes full names.
5766 print $fh "$sub[$i]{context} = $s$args"
5767 . " called from $file"
5768 . " line $sub[$i]{line}\n";
5770 } ## end for ($i = 0 ; $i <= $#sub...
5771 } ## end sub print_trace
5773 =head2 dump_trace(skip[,count])
5775 Actually collect the traceback information available via C<caller()>. It does
5776 some filtering and cleanup of the data, but mostly it just collects it to
5777 make C<print_trace()>'s job easier.
5779 C<skip> defines the number of stack frames to be skipped, working backwards
5780 from the most current. C<count> determines the total number of frames to
5781 be returned; all of them (well, the first 10^9) are returned if C<count>
5784 This routine returns a list of hashes, from most-recent to least-recent
5785 stack frame. Each has the following keys and values:
5789 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
5791 =item * C<sub> - subroutine name, or C<eval> information
5793 =item * C<args> - undef, or a reference to an array of arguments
5795 =item * C<file> - the file in which this item was defined (if any)
5797 =item * C<line> - the line on which it was defined
5805 # How many levels to skip.
5808 # How many levels to show. (1e9 is a cheap way of saying "all of them";
5809 # it's unlikely that we'll have more than a billion stack frames. If you
5810 # do, you've got an awfully big machine...)
5811 my $count = shift || 1e9;
5813 # We increment skip because caller(1) is the first level *back* from
5814 # the current one. Add $skip to the count of frames so we have a
5815 # simple stop criterion, counting from $skip to $count+$skip.
5819 # These variables are used to capture output from caller();
5820 my ( $p, $file, $line, $sub, $h, $context );
5822 my ( $e, $r, @a, @sub, $args );
5824 # XXX Okay... why'd we do that?
5825 my $nothard = not $frame & 8;
5828 # Do not want to trace this.
5829 my $otrace = $trace;
5832 # Start out at the skip count.
5833 # If we haven't reached the number of frames requested, and caller() is
5834 # still returning something, stay in the loop. (If we pass the requested
5835 # number of stack frames, or we run out - caller() returns nothing - we
5837 # Up the stack frame index to go back one more level each time.
5841 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
5846 # Go through the arguments and save them for later.
5848 for my $arg (@args) {
5850 if ( not defined $arg ) { # undefined parameter
5854 elsif ( $nothard and tied $arg ) { # tied parameter
5857 elsif ( $nothard and $type = ref $arg ) { # reference
5858 push @a, "ref($type)";
5860 else { # can be stringified
5862 "$arg"; # Safe to stringify now - should not call f().
5864 # Backslash any single-quotes or backslashes.
5867 # Single-quote it unless it's a number or a colon-separated
5870 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
5872 # Turn high-bit characters into meta-whatever.
5873 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
5875 # Turn control characters into ^-whatever.
5876 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
5879 } ## end else [ if (not defined $arg)
5880 } ## end for $arg (@args)
5882 # If context is true, this is array (@)context.
5883 # If context is false, this is scalar ($) context.
5884 # If neither, context isn't defined. (This is apparently a 'can't
5886 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
5888 # if the sub has args ($h true), make an anonymous array of the
5890 $args = $h ? [@a] : undef;
5892 # remove trailing newline-whitespace-semicolon-end of line sequence
5893 # from the eval text, if any.
5894 $e =~ s/\n\s*\;\s*\Z// if $e;
5896 # Escape backslashed single-quotes again if necessary.
5897 $e =~ s/([\\\'])/\\$1/g if $e;
5899 # if the require flag is true, the eval text is from a require.
5901 $sub = "require '$e'";
5904 # if it's false, the eval text is really from an eval.
5905 elsif ( defined $r ) {
5909 # If the sub is '(eval)', this is a block eval, meaning we don't
5910 # know what the eval'ed text actually was.
5911 elsif ( $sub eq '(eval)' ) {
5912 $sub = "eval {...}";
5915 # Stick the collected information into @sub as an anonymous hash.
5919 context => $context,
5927 # Stop processing frames if the user hit control-C.
5929 } ## end for ($i = $skip ; $i < ...
5931 # Restore the trace value again.
5934 } ## end sub dump_trace
5938 C<action()> takes input provided as the argument to an add-action command,
5939 either pre- or post-, and makes sure it's a complete command. It doesn't do
5940 any fancy parsing; it just keeps reading input until it gets a string
5941 without a trailing backslash.
5948 while ( $action =~ s/\\$// ) {
5950 # We have a backslash on the end. Read more.
5952 } ## end while ($action =~ s/\\$//)
5954 # Return the assembled action.
5960 This routine mostly just packages up a regular expression to be used
5961 to check that the thing it's being matched against has properly-matched
5964 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
5965 speeds things up by only creating the qr//'ed expression once; if it's
5966 already defined, we don't try to define it again. A speed hack.
5970 use vars qw($balanced_brace_re);
5974 # I hate using globals!
5975 $balanced_brace_re ||= qr{
5978 (?> [^{}] + ) # Non-parens without backtracking
5980 (??{ $balanced_brace_re }) # Group with matching parens
5984 return $_[0] !~ m/$balanced_brace_re/;
5985 } ## end sub unbalanced
5989 C<gets()> is a primitive (very primitive) routine to read continuations.
5990 It was devised for reading continuations for actions.
5991 it just reads more input with C<readline()> and returns it.
5996 &readline("cont: ");
5999 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger
6001 The C<system()> function assumes that it can just go ahead and use STDIN and
6002 STDOUT, but under the debugger, we want it to use the debugger's input and
6005 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes
6006 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
6007 and then puts everything back again.
6013 # We save, change, then restore STDIN and STDOUT to avoid fork() since
6014 # some non-Unix systems can do system() but have problems with fork().
6015 open( SAVEIN, "<&STDIN" ) || &warn("Can't save STDIN");
6016 open( SAVEOUT, ">&STDOUT" ) || &warn("Can't save STDOUT");
6017 open( STDIN, "<&IN" ) || &warn("Can't redirect STDIN");
6018 open( STDOUT, ">&OUT" ) || &warn("Can't redirect STDOUT");
6020 # XXX: using csh or tcsh destroys sigint retvals!
6022 open( STDIN, "<&SAVEIN" ) || &warn("Can't restore STDIN");
6023 open( STDOUT, ">&SAVEOUT" ) || &warn("Can't restore STDOUT");
6027 # most of the $? crud was coping with broken cshisms
6029 &warn( "(Command exited ", ( $? >> 8 ), ")\n" );
6033 "(Command died of SIG#",
6035 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6044 =head1 TTY MANAGEMENT
6046 The subs here do some of the terminal management for multiple debuggers.
6050 Top-level function called when we want to set up a new terminal for use
6053 If the C<noTTY> debugger option was set, we'll either use the terminal
6054 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6055 to find one. If we're a forked debugger, we call C<resetterm> to try to
6056 get a whole new terminal if we can.
6058 In either case, we set up the terminal next. If the C<ReadLine> option was
6059 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6060 the appropriate attributes. We then
6064 use vars qw($ornaments);
6065 use vars qw($rl_attribs);
6069 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6072 require Term::ReadLine;
6074 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6077 my ( $i, $o ) = split $tty, /,/;
6078 $o = $i unless defined $o;
6079 open( IN, "<$i" ) or die "Cannot open TTY '$i' for read: $!";
6080 open( OUT, ">$o" ) or die "Cannot open TTY '$o' for write: $!";
6083 my $sel = select($OUT);
6088 # We don't have a TTY - try to find one via Term::Rendezvous.
6090 require Term::Rendezvous;
6092 # See if we have anything to pass to Term::Rendezvous.
6093 # Use $HOME/.perldbtty$$ if not.
6094 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6096 # Rendezvous and get the filehandles.
6097 my $term_rv = Term::Rendezvous->new( $rv );
6099 $OUT = $term_rv->OUT;
6100 } ## end else [ if ($tty)
6101 } ## end if ($notty)
6103 # We're a daughter debugger. Try to fork off another TTY.
6104 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6108 # If we shouldn't use Term::ReadLine, don't.
6110 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6113 # We're using Term::ReadLine. Get all the attributes for this terminal.
6115 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6117 $rl_attribs = $term->Attribs;
6118 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6119 if defined $rl_attribs->{basic_word_break_characters}
6120 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6121 $rl_attribs->{special_prefixes} = '$@&%';
6122 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6123 $rl_attribs->{completion_function} = \&db_complete;
6124 } ## end else [ if (!$rl)
6126 # Set up the LINEINFO filehandle.
6127 $LINEINFO = $OUT unless defined $LINEINFO;
6128 $lineinfo = $console unless defined $lineinfo;
6134 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6135 $term->SetHistory(@hist);
6138 # XXX Ornaments are turned on unconditionally, which is not
6139 # always a good thing.
6140 ornaments($ornaments) if defined $ornaments;
6142 } ## end sub setterm
6145 $histfile //= option_val("HistFile", undef);
6146 return unless defined $histfile;
6147 open my $fh, "<", $histfile or return;
6158 return unless defined $histfile;
6159 eval { require File::Path } or return;
6160 eval { require File::Basename } or return;
6161 File::Path::mkpath(File::Basename::dirname($histfile));
6162 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6163 $histsize //= option_val("HistSize",100);
6164 my @copy = grep { $_ ne '?' } @hist;
6165 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6166 for ($start .. $#copy) {
6167 print $fh "$copy[$_]\n";
6169 close $fh or die "Could not write '$histfile': $!";
6172 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6174 When the process being debugged forks, or the process invokes a command
6175 via C<system()> which starts a new debugger, we need to be able to get a new
6176 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6177 fight over the terminal, and you can never quite be sure who's going to get the
6178 input you're typing.
6180 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6181 is tasked with doing all the necessary operating system mojo to get a new
6182 TTY (and probably another window) and to direct the new debugger to read and
6185 The debugger provides C<get_fork_TTY> functions which work for TCP
6186 socket servers, X11, OS/2, and Mac OS X. Other systems are not
6187 supported. You are encouraged to write C<get_fork_TTY> functions which
6188 work for I<your> platform and contribute them.
6190 =head3 C<socket_get_fork_TTY>
6194 sub connect_remoteport {
6197 my $socket = IO::Socket::INET->new(
6199 PeerAddr => $remoteport,
6203 die "Unable to connect to remote host: $remoteport\n";
6208 sub socket_get_fork_TTY {
6209 $tty = $LINEINFO = $IN = $OUT = connect_remoteport();
6211 # Do I need to worry about setting $term?
6213 reset_IN_OUT( $IN, $OUT );
6217 =head3 C<xterm_get_fork_TTY>
6219 This function provides the C<get_fork_TTY> function for X11. If a
6220 program running under the debugger forks, a new <xterm> window is opened and
6221 the subsidiary debugger is directed there.
6223 The C<open()> call is of particular note here. We have the new C<xterm>
6224 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6225 command (which prints the device name of the TTY we'll want to use for input
6226 and output to STDOUT, then C<sleep> for a very long time, routing this output
6227 to file number 3. This way we can simply read from the <XT> filehandle (which
6228 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6230 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6235 sub xterm_get_fork_TTY {
6236 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6238 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6241 # Get the output from 'tty' and clean it up a little.
6245 $pidprompt = ''; # Shown anyway in titlebar
6247 # We need $term defined or we can not switch to the newly created xterm
6248 if ($tty ne '' && !defined $term) {
6249 require Term::ReadLine;
6251 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6254 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6257 # There's our new TTY.
6259 } ## end sub xterm_get_fork_TTY
6261 =head3 C<os2_get_fork_TTY>
6263 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6267 # This example function resets $IN, $OUT itself
6269 sub os2_get_fork_TTY { # A simplification of the following (and works without):
6271 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6272 my %opt = ( title => "Daughter Perl debugger $pids $name",
6273 ($rl ? (read_by_key => 1) : ()) );
6274 require OS2::Process;
6275 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
6277 $pidprompt = ''; # Shown anyway in titlebar
6278 reset_IN_OUT($in, $out);
6280 return ''; # Indicate that reset_IN_OUT is called
6281 } ## end sub os2_get_fork_TTY
6283 =head3 C<macosx_get_fork_TTY>
6285 The Mac OS X version uses AppleScript to tell Terminal.app to create
6290 # Notes about Terminal.app's AppleScript support,
6291 # (aka things that might break in future OS versions).
6293 # The "do script" command doesn't return a reference to the new window
6294 # it creates, but since it appears frontmost and windows are enumerated
6295 # front to back, we can use "first window" === "window 1".
6297 # Since "do script" is implemented by supplying the argument (plus a
6298 # return character) as terminal input, there's a potential race condition
6299 # where the debugger could beat the shell to reading the command.
6300 # To prevent this, we wait for the screen to clear before proceeding.
6303 # There's no direct accessor for the tty device name, so we fiddle
6304 # with the window title options until it says what we want.
6307 # There _is_ a direct accessor for the tty device name, _and_ there's
6308 # a new possible component of the window title (the name of the settings
6309 # set). A separate version is needed.
6311 my @script_versions=
6313 ([237, <<'__LEOPARD__'],
6314 tell application "Terminal"
6315 do script "clear;exec sleep 100000"
6316 tell first tab of first window
6318 set custom title to "forked perl debugger"
6319 set title displays custom title to true
6320 repeat while (length of first paragraph of (get contents)) > 0
6328 [100, <<'__JAGUAR_TIGER__'],
6329 tell application "Terminal"
6330 do script "clear;exec sleep 100000"
6332 set title displays shell path to false
6333 set title displays window size to false
6334 set title displays file name to false
6335 set title displays device name to true
6336 set title displays custom title to true
6337 set custom title to ""
6338 copy "/dev/" & name to thetty
6339 set custom title to "forked perl debugger"
6340 repeat while (length of first paragraph of (get contents)) > 0
6350 sub macosx_get_fork_TTY
6352 my($version,$script,$pipe,$tty);
6354 return unless $version=$ENV{TERM_PROGRAM_VERSION};
6355 foreach my $entry (@script_versions) {
6356 if ($version>=$entry->[0]) {
6357 $script=$entry->[1];
6361 return unless defined($script);
6362 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
6363 $tty=readline($pipe);
6365 return unless defined($tty) && $tty =~ m(^/dev/);
6370 =head2 C<create_IN_OUT($flags)>
6372 Create a new pair of filehandles, pointing to a new TTY. If impossible,
6373 try to diagnose why.
6379 =item * 1 - Don't know how to create a new TTY.
6381 =item * 2 - Debugger has forked, but we can't get a new TTY.
6383 =item * 4 - standard debugger startup is happening.
6389 use vars qw($fork_TTY);
6391 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
6393 # If we know how to get a new TTY, do it! $in will have
6394 # the TTY name if get_fork_TTY works.
6395 my $in = &get_fork_TTY if defined &get_fork_TTY;
6397 # It used to be that
6398 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
6400 if ( not defined $in ) {
6403 # We don't know how.
6404 print_help(<<EOP) if $why == 1;
6405 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6409 print_help(<<EOP) if $why == 2;
6410 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6411 This may be an asynchronous session, so the parent debugger may be active.
6414 # Note that both debuggers are fighting over the same input.
6415 print_help(<<EOP) if $why != 4;
6416 Since two debuggers fight for the same TTY, input is severely entangled.
6420 I know how to switch the output to a different window in xterms, OS/2
6421 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
6422 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
6423 B<DB::get_fork_TTY()> returning this.
6425 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6426 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6429 } ## end if (not defined $in)
6430 elsif ( $in ne '' ) {
6434 $console = ''; # Indicate no need to open-from-the-console
6437 } ## end sub create_IN_OUT
6441 Handles rejiggering the prompt when we've forked off a new debugger.
6443 If the new debugger happened because of a C<system()> that invoked a
6444 program under the debugger, the arrow between the old pid and the new
6445 in the prompt has I<two> dashes instead of one.
6447 We take the current list of pids and add this one to the end. If there
6448 isn't any list yet, we make one up out of the initial pid associated with
6449 the terminal and our new pid, sticking an arrow (either one-dashed or
6450 two dashed) in between them.
6452 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6453 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6458 sub resetterm { # We forked, so we need a different TTY
6460 # Needs to be passed to create_IN_OUT() as well.
6463 # resetterm(2): got in here because of a system() starting a debugger.
6464 # resetterm(1): just forked.
6465 my $systemed = $in > 1 ? '-' : '';
6467 # If there's already a list of pids, add this to the end.
6469 $pids =~ s/\]/$systemed->$$]/;
6472 # No pid list. Time to make one.
6474 $pids = "[$term_pid->$$]";
6477 # The prompt we're going to be using for this debugger.
6480 # We now 0wnz this terminal.
6483 # Just return if we're not supposed to try to create a new TTY.
6484 return unless $CreateTTY & $in;
6486 # Try to create a new IN/OUT pair.
6488 } ## end sub resetterm
6492 First, we handle stuff in the typeahead buffer. If there is any, we shift off
6493 the next line, print a message saying we got it, add it to the terminal
6494 history (if possible), and return it.
6496 If there's nothing in the typeahead buffer, check the command filehandle stack.
6497 If there are any filehandles there, read from the last one, and return the line
6498 if we got one. If not, we pop the filehandle off and close it, and try the
6499 next one up the stack.
6501 If we've emptied the filehandle stack, we check to see if we've got a socket
6502 open, and we read that and return it if we do. If we don't, we just call the
6503 core C<readline()> and return its value.
6509 # Localize to prevent it from being smashed in the program being debugged.
6512 # Pull a line out of the typeahead if there's stuff there.
6515 # How many lines left.
6516 my $left = @typeahead;
6518 # Get the next line.
6519 my $got = shift @typeahead;
6521 # Print a message saying we got input from the typeahead.
6523 print $OUT "auto(-$left)", shift, $got, "\n";
6525 # Add it to the terminal history (if possible).
6526 $term->AddHistory($got)
6528 and defined $term->Features->{addHistory};
6530 } ## end if (@typeahead)
6532 # We really need to read some input. Turn off entry/exit trace and
6533 # return value printing.
6537 # If there are stacked filehandles to read from ...
6540 # Read from the last one in the stack.
6541 my $line = CORE::readline( $cmdfhs[-1] );
6543 # If we got a line ...
6545 ? ( print $OUT ">> $line" and return $line ) # Echo and return
6546 : close pop @cmdfhs; # Pop and close
6547 } ## end while (@cmdfhs)
6549 # Nothing on the filehandle stack. Socket?
6550 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
6552 # Send anything we have to send.
6553 $OUT->write( join( '', @_ ) );
6555 # Receive anything there is to receive.
6559 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
6560 # XXX Don't know. You tell me.
6561 } while length $buf and ($stuff .= $buf) !~ /\n/;
6565 } ## end if (ref $OUT and UNIVERSAL::isa...
6567 # No socket. Just read from the terminal.
6569 $term->readline(@_);
6571 } ## end sub readline
6573 =head1 OPTIONS SUPPORT ROUTINES
6575 These routines handle listing and setting option values.
6577 =head2 C<dump_option> - list the current value of an option setting
6579 This routine uses C<option_val> to look up the value for an option.
6580 It cleans up escaped single-quotes and then displays the option and
6586 my ( $opt, $val ) = @_;
6587 $val = option_val( $opt, 'N/A' );
6588 $val =~ s/([\\\'])/\\$1/g;
6589 printf $OUT "%20s = '%s'\n", $opt, $val;
6590 } ## end sub dump_option
6592 sub options2remember {
6593 foreach my $k (@RememberOnROptions) {
6594 $option{$k} = option_val( $k, 'N/A' );
6599 =head2 C<option_val> - find the current value of an option
6601 This can't just be a simple hash lookup because of the indirect way that
6602 the option values are stored. Some are retrieved by calling a subroutine,
6603 some are just variables.
6605 You must supply a default value to be used in case the option isn't set.
6610 my ( $opt, $default ) = @_;
6613 # Does this option exist, and is it a variable?
6614 # If so, retrieve the value via the value in %optionVars.
6615 if ( defined $optionVars{$opt}
6616 and defined ${ $optionVars{$opt} } )
6618 $val = ${ $optionVars{$opt} };
6621 # Does this option exist, and it's a subroutine?
6622 # If so, call the subroutine via the ref in %optionAction
6623 # and capture the value.
6624 elsif ( defined $optionAction{$opt}
6625 and defined &{ $optionAction{$opt} } )
6627 $val = &{ $optionAction{$opt} }();
6630 # If there's an action or variable for the supplied option,
6631 # but no value was set, use the default.
6632 elsif (defined $optionAction{$opt} and not defined $option{$opt}
6633 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
6638 # Otherwise, do the simple hash lookup.
6640 $val = $option{$opt};
6643 # If the value isn't defined, use the default.
6644 # Then return whatever the value is.
6645 $val = $default unless defined $val;
6647 } ## end sub option_val
6649 =head2 C<parse_options>
6651 Handles the parsing and execution of option setting/displaying commands.
6653 An option entered by itself is assumed to be I<set me to 1> (the default value)
6654 if the option is a boolean one. If not, the user is prompted to enter a valid
6655 value or to query the current value (via C<option? >).
6657 If C<option=value> is entered, we try to extract a quoted string from the
6658 value (if it is quoted). If it's not, we just use the whole value as-is.
6660 We load any modules required to service this option, and then we set it: if
6661 it just gets stuck in a variable, we do that; if there's a subroutine to
6662 handle setting the option, we call that.
6664 Finally, if we're running in interactive mode, we display the effect of the
6665 user's command back to the terminal, skipping this if we're setting things
6666 during initialization.
6676 # These options need a value. Don't allow them to be clobbered by accident.
6677 my %opt_needs_val = map { ( $_ => 1 ) } qw{
6678 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
6679 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
6685 # Clean off excess leading whitespace.
6688 # Options are always all word characters, followed by a non-word
6690 s/^(\w+)(\W?)// or print( $OUT "Invalid option '$_'\n" ), last;
6691 my ( $opt, $sep ) = ( $1, $2 );
6693 # Make sure that such an option exists.
6694 my $matches = grep( /^\Q$opt/ && ( $option = $_ ), @options )
6695 || grep( /^\Q$opt/i && ( $option = $_ ), @options );
6697 print( $OUT "Unknown option '$opt'\n" ), next unless $matches;
6698 print( $OUT "Ambiguous option '$opt'\n" ), next if $matches > 1;
6701 # '?' as separator means query, but must have whitespace after it.
6702 if ( "?" eq $sep ) {
6703 print( $OUT "Option query '$opt?' followed by non-space '$_'\n" ),
6707 #&dump_option($opt);
6708 } ## end if ("?" eq $sep)
6710 # Separator is whitespace (or just a carriage return).
6711 # They're going for a default, which we assume is 1.
6712 elsif ( $sep !~ /\S/ ) {
6714 $val = "1"; # this is an evil default; make 'em set it!
6717 # Separator is =. Trying to set a value.
6718 elsif ( $sep eq "=" ) {
6720 # If quoted, extract a quoted string.
6721 if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
6723 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
6726 # Not quoted. Use the whole thing. Warn about 'option='.
6730 print OUT qq(Option better cleared using $opt=""\n)
6732 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
6734 } ## end elsif ($sep eq "=")
6736 # "Quoted" with [], <>, or {}.
6737 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
6739 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
6740 s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
6741 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last;
6742 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
6743 } ## end else [ if ("?" eq $sep)
6745 # Exclude non-booleans from getting set to 1 by default.
6746 if ( $opt_needs_val{$option} && $val_defaulted ) {
6747 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
6749 "Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n";
6751 } ## end if ($opt_needs_val{$option...
6753 # Save the option value.
6754 $option{$option} = $val if defined $val;
6756 # Load any module that this option requires.
6760 require '$optionRequire{$option}';
6762 } || die $@ # XXX: shouldn't happen
6763 if defined $optionRequire{$option}
6767 # Stick it in the proper variable if it goes in a variable.
6768 ${ $optionVars{$option} } = $val
6769 if defined $optionVars{$option}
6772 # Call the appropriate sub if it gets set via sub.
6773 &{ $optionAction{$option} }($val)
6774 if defined $optionAction{$option}
6775 && defined &{ $optionAction{$option} }
6778 # Not initialization - echo the value we set it to.
6779 dump_option($option) unless $OUT eq \*STDERR;
6780 } ## end while (length)
6781 } ## end sub parse_options
6783 =head1 RESTART SUPPORT
6785 These routines are used to store (and restore) lists of items in environment
6786 variables during a restart.
6790 Set_list packages up items to be stored in a set of environment variables
6791 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
6792 the values). Values outside the standard ASCII charset are stored by encoding
6793 then as hexadecimal values.
6798 my ( $stem, @list ) = @_;
6801 # VAR_n: how many we have. Scalar assignment gets the number of items.
6802 $ENV{"${stem}_n"} = @list;
6804 # Grab each item in the list, escape the backslashes, encode the non-ASCII
6805 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
6806 for my $i ( 0 .. $#list ) {
6808 $val =~ s/\\/\\\\/g;
6809 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
6810 $ENV{"${stem}_$i"} = $val;
6811 } ## end for $i (0 .. $#list)
6812 } ## end sub set_list
6816 Reverse the set_list operation: grab VAR_n to see how many we should be getting
6817 back, and then pull VAR_0, VAR_1. etc. back out.
6824 my $n = delete $ENV{"${stem}_n"};
6826 for my $i ( 0 .. $n - 1 ) {
6827 $val = delete $ENV{"${stem}_$i"};
6828 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
6832 } ## end sub get_list
6834 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
6838 The C<catch()> subroutine is the essence of fast and low-impact. We simply
6839 set an already-existing global scalar variable to a constant value. This
6840 avoids allocating any memory possibly in the middle of something that will
6841 get all confused if we do, particularly under I<unsafe signals>.
6847 return; # Put nothing on the stack - malloc/free land!
6852 C<warn> emits a warning, by joining together its arguments and printing
6853 them, with couple of fillips.
6855 If the composited message I<doesn't> end with a newline, we automatically
6856 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
6857 to be set to the filehandle to be used to output warnings; it makes no
6858 assumptions about what filehandles are available.
6863 my ($msg) = join( "", @_ );
6864 $msg .= ": $!\n" unless $msg =~ /\n$/;
6869 =head1 INITIALIZATION TTY SUPPORT
6871 =head2 C<reset_IN_OUT>
6873 This routine handles restoring the debugger's input and output filehandles
6874 after we've tried and failed to move them elsewhere. In addition, it assigns
6875 the debugger's output filehandle to $LINEINFO if it was already open there.
6880 my $switch_li = $LINEINFO eq $OUT;
6882 # If there's a term and it's able to get a new tty, try to get one.
6883 if ( $term and $term->Features->{newTTY} ) {
6884 ( $IN, $OUT ) = ( shift, shift );
6885 $term->newTTY( $IN, $OUT );
6888 # This term can't get a new tty now. Better luck later.
6890 &warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n");
6893 # Set the filehndles up as they were.
6895 ( $IN, $OUT ) = ( shift, shift );
6898 # Unbuffer the output filehandle.
6899 my $o = select $OUT;
6903 # Point LINEINFO to the same output filehandle if it was there before.
6904 $LINEINFO = $OUT if $switch_li;
6905 } ## end sub reset_IN_OUT
6907 =head1 OPTION SUPPORT ROUTINES
6909 The following routines are used to process some of the more complicated
6914 Sets the input and output filehandles to the specified files or pipes.
6915 If the terminal supports switching, we go ahead and do it. If not, and
6916 there's already a terminal in place, we save the information to take effect
6919 If there's no terminal yet (for instance, during debugger initialization),
6920 we go ahead and set C<$console> and C<$tty> to the file indicated.
6926 if ( @_ and $term and $term->Features->{newTTY} ) {
6928 # This terminal supports switching to a new TTY.
6929 # Can be a list of two files, or on string containing both names,
6931 # XXX Should this perhaps be an assignment from @_?
6932 my ( $in, $out ) = shift;
6935 # Split list apart if supplied.
6936 ( $in, $out ) = split /,/, $in, 2;
6940 # Use the same file for both input and output.
6944 # Open file onto the debugger's filehandles, if you can.
6945 open IN, $in or die "cannot open '$in' for read: $!";
6946 open OUT, ">$out" or die "cannot open '$out' for write: $!";
6948 # Swap to the new filehandles.
6949 reset_IN_OUT( \*IN, \*OUT );
6951 # Save the setting for later.
6953 } ## end if (@_ and $term and $term...
6955 # Terminal doesn't support new TTY, or doesn't support readline.
6956 # Can't do it now, try restarting.
6957 &warn("Too late to set TTY, enabled on next 'R'!\n") if $term and @_;
6959 # Useful if done through PERLDB_OPTS:
6960 $console = $tty = shift if @_;
6962 # Return whatever the TTY is.
6968 Sets the C<$notty> global, controlling whether or not the debugger tries to
6969 get a terminal to read from. If called after a terminal is already in place,
6970 we save the value to use it if we're restarted.
6976 &warn("Too late to set noTTY, enabled on next 'R'!\n") if @_;
6978 $notty = shift if @_;
6984 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
6985 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
6986 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
6987 the value in case a restart is done so we can change it then.
6993 &warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_;
6997 } ## end sub ReadLine
6999 =head2 C<RemotePort>
7001 Sets the port that the debugger will try to connect to when starting up.
7002 If the terminal's already been set up, we can't do it, but we remember the
7003 setting in case the user does a restart.
7009 &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
7011 $remoteport = shift if @_;
7013 } ## end sub RemotePort
7017 Checks with the terminal to see if C<Tk> is running, and returns true or
7018 false. Returns false if the current terminal doesn't support C<readline>.
7023 if ( ${ $term->Features }{tkRunning} ) {
7024 return $term->tkRunning(@_);
7028 print $OUT "tkRunning not supported by current ReadLine package.\n";
7031 } ## end sub tkRunning
7035 Sets nonstop mode. If a terminal's already been set up, it's too late; the
7036 debugger remembers the setting in case you restart, though.
7042 &warn("Too late to set up NonStop mode, enabled on next 'R'!\n")
7045 $runnonstop = shift if @_;
7047 } ## end sub NonStop
7051 &warn("Some flag changes could not take effect until next 'R'!\n")
7054 $^P = parse_DollarCaretP_flags(shift) if @_;
7055 expand_DollarCaretP_flags($^P);
7060 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
7068 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7075 Sets the shell escape command, and generates a printable copy to be used
7082 # If we got an argument, meta-quote it, and add '\b' if it
7083 # ends in a word character.
7085 $sh = quotemeta shift;
7086 $sh .= "\\b" if $sh =~ /\w$/;
7089 # Generate the printable version for the help:
7090 $psh = $sh; # copy it
7091 $psh =~ s/\\b$//; # Take off trailing \b if any
7092 $psh =~ s/\\(.)/$1/g; # De-escape
7093 $psh; # return the printable version
7094 } ## end sub shellBang
7098 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7099 was passed as the argument. (This means you can't override the terminal's
7105 if ( defined $term ) {
7107 # We don't want to show warning backtraces, but we do want die() ones.
7108 local ( $warnLevel, $dieLevel ) = ( 0, 1 );
7110 # No ornaments if the terminal doesn't support them.
7111 return '' unless $term->Features->{ornaments};
7112 eval { $term->ornaments(@_) } || '';
7115 # Use what was passed in if we can't determine it ourselves.
7119 } ## end sub ornaments
7121 =head2 C<recallCommand>
7123 Sets the recall command, and builds a printable version which will appear in
7130 # If there is input, metaquote it. Add '\b' if it ends with a word
7133 $rc = quotemeta shift;
7134 $rc .= "\\b" if $rc =~ /\w$/;
7137 # Build it into a printable version.
7138 $prc = $rc; # Copy it
7139 $prc =~ s/\\b$//; # Remove trailing \b
7140 $prc =~ s/\\(.)/$1/g; # Remove escapes
7141 $prc; # Return the printable version
7142 } ## end sub recallCommand
7144 =head2 C<LineInfo> - where the line number information goes
7146 Called with no arguments, returns the file or pipe that line info should go to.
7148 Called with an argument (a file or a pipe), it opens that onto the
7149 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7150 file or pipe again to the caller.
7155 return $lineinfo unless @_;
7158 # If this is a valid "thing to be opened for output", tack a
7159 # '>' onto the front.
7160 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7162 # If this is a pipe, the stream points to a slave editor.
7163 $slave_editor = ( $stream =~ /^\|/ );
7165 # Open it up and unbuffer it.
7166 open( LINEINFO, "$stream" ) || &warn("Cannot open '$stream' for write");
7167 $LINEINFO = \*LINEINFO;
7168 my $save = select($LINEINFO);
7172 # Hand the file or pipe back again.
7174 } ## end sub LineInfo
7176 =head1 COMMAND SUPPORT ROUTINES
7178 These subroutines provide functionality for various commands.
7180 =head2 C<list_modules>
7182 For the C<M> command: list modules loaded and their versions.
7183 Essentially just runs through the keys in %INC, picks each package's
7184 C<$VERSION> variable, gets the file name, and formats the information
7189 sub list_modules { # versions
7193 # keys are the "as-loaded" name, values are the fully-qualified path
7194 # to the file itself.
7196 $file = $_; # get the module name
7197 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7198 s,/,::,g; # change '/' to '::'
7199 s/^perl5db$/DB/; # Special case: debugger
7200 # moves to package DB
7201 s/^Term::ReadLine::readline$/readline/; # simplify readline
7203 # If the package has a $VERSION package global (as all good packages
7204 # should!) decode it and save as partial message.
7205 my $pkg_version = do { no strict 'refs'; ${ $_ . '::VERSION' } };
7206 if ( defined $pkg_version ) {
7207 $version{$file} = "$pkg_version from ";
7210 # Finish up the message with the file the package came from.
7211 $version{$file} .= $INC{$file};
7212 } ## end for (keys %INC)
7214 # Hey, dumpit() formats a hash nicely, so why not use it?
7215 dumpit( $OUT, \%version );
7216 } ## end sub list_modules
7220 Sets up the monster string used to format and print the help.
7222 =head3 HELP MESSAGE FORMAT
7224 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
7225 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
7226 easy to parse and portable, but which still allows the help to be a little
7227 nicer than just plain text.
7229 Essentially, you define the command name (usually marked up with C<< B<> >>
7230 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
7231 newline. The descriptive text can also be marked up in the same way. If you
7232 need to continue the descriptive text to another line, start that line with
7233 just tabs and then enter the marked-up text.
7235 If you are modifying the help text, I<be careful>. The help-string parser is
7236 not very sophisticated, and if you don't follow these rules it will mangle the
7237 help beyond hope until you fix the string.
7241 use vars qw($pre580_help);
7242 use vars qw($pre580_summary);
7246 # XXX: make sure there are tabs between the command and explanation,
7247 # or print_help will screw up your formatting if you have
7248 # eeevil ornaments enabled. This is an insane mess.
7251 Help is currently only available for the new 5.8 command set.
7252 No help is available for the old command set.
7253 We assume you know what you're doing if you switch to it.
7256 B<s> [I<expr>] Single step [in I<expr>].
7257 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7258 <B<CR>> Repeat last B<n> or B<s> command.
7259 B<r> Return from current subroutine.
7260 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7261 at the specified position.
7262 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7263 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7264 B<l> I<line> List single I<line>.
7265 B<l> I<subname> List first window of lines from subroutine.
7266 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7267 B<l> List next window of lines.
7268 B<-> List previous window of lines.
7269 B<v> [I<line>] View window around I<line>.
7270 B<.> Return to the executed line.
7271 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7272 I<filename> may be either the full name of the file, or a regular
7273 expression matching the full file name:
7274 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7275 Evals (with saved bodies) are considered to be filenames:
7276 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7277 (in the order of execution).
7278 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7279 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7280 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
7281 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7282 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth).
7283 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
7284 B<b> Sets breakpoint on current line)
7285 B<b> [I<line>] [I<condition>]
7286 Set breakpoint; I<line> defaults to the current execution line;
7287 I<condition> breaks if it evaluates to true, defaults to '1'.
7288 B<b> I<subname> [I<condition>]
7289 Set breakpoint at first line of subroutine.
7290 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7291 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7292 B<b> B<postpone> I<subname> [I<condition>]
7293 Set breakpoint at first line of subroutine after
7295 B<b> B<compile> I<subname>
7296 Stop after the subroutine is compiled.
7297 B<B> [I<line>] Delete the breakpoint for I<line>.
7298 B<B> I<*> Delete all breakpoints.
7299 B<a> [I<line>] I<command>
7300 Set an action to be done before the I<line> is executed;
7301 I<line> defaults to the current execution line.
7302 Sequence is: check for breakpoint/watchpoint, print line
7303 if necessary, do action, prompt user if necessary,
7306 B<A> [I<line>] Delete the action for I<line>.
7307 B<A> I<*> Delete all actions.
7308 B<w> I<expr> Add a global watch-expression.
7310 B<W> I<expr> Delete a global watch-expression.
7311 B<W> I<*> Delete all watch-expressions.
7312 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7313 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7314 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7315 B<x> I<expr> Evals expression in list context, dumps the result.
7316 B<m> I<expr> Evals expression in list context, prints methods callable
7317 on the first element of the result.
7318 B<m> I<class> Prints methods callable via the given class.
7319 B<M> Show versions of loaded modules.
7320 B<i> I<class> Prints nested parents of given class.
7321 B<e> Display current thread id.
7322 B<E> Display all thread ids the current one will be identified: <n>.
7323 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7325 B<<> ? List Perl commands to run before each prompt.
7326 B<<> I<expr> Define Perl command to run before each prompt.
7327 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7328 B<< *> Delete the list of perl commands to run before each prompt.
7329 B<>> ? List Perl commands to run after each prompt.
7330 B<>> I<expr> Define Perl command to run after each prompt.
7331 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7332 B<>>B< *> Delete the list of Perl commands to run after each prompt.
7333 B<{> I<db_command> Define debugger command to run before each prompt.
7334 B<{> ? List debugger commands to run before each prompt.
7335 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7336 B<{ *> Delete the list of debugger commands to run before each prompt.
7337 B<$prc> I<number> Redo a previous command (default previous command).
7338 B<$prc> I<-number> Redo number'th-to-last command.
7339 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7340 See 'B<O> I<recallCommand>' too.
7341 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7346 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7348 See 'B<O> I<shellBang>' too.
7349 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7350 B<save> I<file> Save current debugger session (actual history) to I<file>.
7351 B<rerun> Rerun session to current position.
7352 B<rerun> I<n> Rerun session to numbered command.
7353 B<rerun> I<-n> Rerun session to number'th-to-last command.
7354 B<H> I<-number> Display last number commands (default all).
7355 B<H> I<*> Delete complete history.
7356 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7357 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7358 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well.
7359 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7360 I<command> Execute as a perl statement in current package.
7361 B<R> Pure-man-restart of debugger, some of debugger state
7362 and command-line options may be lost.
7363 Currently the following settings are preserved:
7364 history, breakpoints and actions, debugger B<O>ptions
7365 and the following command-line options: I<-w>, I<-I>, I<-e>.
7367 B<o> [I<opt>] ... Set boolean option to true
7368 B<o> [I<opt>B<?>] Query options
7369 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7370 Set options. Use quotes if spaces in value.
7371 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7372 I<pager> program for output of \"|cmd\";
7373 I<tkRunning> run Tk while prompting (with ReadLine);
7374 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7375 I<inhibit_exit> Allows stepping off the end of the script.
7376 I<ImmediateStop> Debugger should stop as early as possible.
7377 I<RemotePort> Remote hostname:port for remote debugging
7378 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7379 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7380 I<compactDump>, I<veryCompact> change style of array and hash dump;
7381 I<globPrint> whether to print contents of globs;
7382 I<DumpDBFiles> dump arrays holding debugged files;
7383 I<DumpPackages> dump symbol tables of packages;
7384 I<DumpReused> dump contents of \"reused\" addresses;
7385 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7386 I<bareStringify> Do not print the overload-stringified value;
7387 Other options include:
7388 I<PrintRet> affects printing of return value after B<r> command,
7389 I<frame> affects printing messages on subroutine entry/exit.
7390 I<AutoTrace> affects printing messages on possible breaking points.
7391 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7392 I<ornaments> affects screen appearance of the command line.
7393 I<CreateTTY> bits control attempts to create a new TTY on events:
7394 1: on fork() 2: debugger is started inside debugger
7396 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7397 You can put additional initialization options I<TTY>, I<noTTY>,
7398 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7399 B<R> after you set them).
7401 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7402 B<h> Summary of debugger commands.
7403 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7404 B<h h> Long help for debugger commands
7405 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7406 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7407 Set B<\$DB::doccmd> to change viewer.
7409 Type '|h h' for a paged display if this was too hard to read.
7411 "; # Fix balance of vi % matching: }}}}
7413 # note: tabs in the following section are not-so-helpful
7414 $summary = <<"END_SUM";
7415 I<List/search source lines:> I<Control script execution:>
7416 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7417 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7418 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7419 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7420 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7421 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7422 I<Debugger controls:> B<L> List break/watch/actions
7423 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr]
7424 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7425 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7426 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7427 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7428 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7429 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7430 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7431 B<q> or B<^D> Quit B<R> Attempt a restart
7432 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7433 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7434 B<p> I<expr> Print expression (uses script's current package).
7435 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7436 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7437 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
7438 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7439 B<e> Display thread id B<E> Display all thread ids.
7440 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7443 # ')}}; # Fix balance of vi % matching
7445 # and this is really numb...
7448 B<s> [I<expr>] Single step [in I<expr>].
7449 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7450 B<CR>> Repeat last B<n> or B<s> command.
7451 B<r> Return from current subroutine.
7452 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7453 at the specified position.
7454 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7455 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7456 B<l> I<line> List single I<line>.
7457 B<l> I<subname> List first window of lines from subroutine.
7458 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7459 B<l> List next window of lines.
7460 B<-> List previous window of lines.
7461 B<w> [I<line>] List window around I<line>.
7462 B<.> Return to the executed line.
7463 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7464 I<filename> may be either the full name of the file, or a regular
7465 expression matching the full file name:
7466 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7467 Evals (with saved bodies) are considered to be filenames:
7468 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7469 (in the order of execution).
7470 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7471 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7472 B<L> List all breakpoints and actions.
7473 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7474 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) .
7475 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
7476 B<b> [I<line>] [I<condition>]
7477 Set breakpoint; I<line> defaults to the current execution line;
7478 I<condition> breaks if it evaluates to true, defaults to '1'.
7479 B<b> I<subname> [I<condition>]
7480 Set breakpoint at first line of subroutine.
7481 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7482 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7483 B<b> B<postpone> I<subname> [I<condition>]
7484 Set breakpoint at first line of subroutine after
7486 B<b> B<compile> I<subname>
7487 Stop after the subroutine is compiled.
7488 B<d> [I<line>] Delete the breakpoint for I<line>.
7489 B<D> Delete all breakpoints.
7490 B<a> [I<line>] I<command>
7491 Set an action to be done before the I<line> is executed;
7492 I<line> defaults to the current execution line.
7493 Sequence is: check for breakpoint/watchpoint, print line
7494 if necessary, do action, prompt user if necessary,
7496 B<a> [I<line>] Delete the action for I<line>.
7497 B<A> Delete all actions.
7498 B<W> I<expr> Add a global watch-expression.
7499 B<W> Delete all watch-expressions.
7500 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7501 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7502 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7503 B<x> I<expr> Evals expression in list context, dumps the result.
7504 B<m> I<expr> Evals expression in list context, prints methods callable
7505 on the first element of the result.
7506 B<m> I<class> Prints methods callable via the given class.
7508 B<<> ? List Perl commands to run before each prompt.
7509 B<<> I<expr> Define Perl command to run before each prompt.
7510 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7511 B<>> ? List Perl commands to run after each prompt.
7512 B<>> I<expr> Define Perl command to run after each prompt.
7513 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7514 B<{> I<db_command> Define debugger command to run before each prompt.
7515 B<{> ? List debugger commands to run before each prompt.
7516 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7517 B<$prc> I<number> Redo a previous command (default previous command).
7518 B<$prc> I<-number> Redo number'th-to-last command.
7519 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7520 See 'B<O> I<recallCommand>' too.
7521 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7526 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7528 See 'B<O> I<shellBang>' too.
7529 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7530 B<H> I<-number> Display last number commands (default all).
7531 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7532 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7533 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7534 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7535 I<command> Execute as a perl statement in current package.
7536 B<v> Show versions of loaded modules.
7537 B<R> Pure-man-restart of debugger, some of debugger state
7538 and command-line options may be lost.
7539 Currently the following settings are preserved:
7540 history, breakpoints and actions, debugger B<O>ptions
7541 and the following command-line options: I<-w>, I<-I>, I<-e>.
7543 B<O> [I<opt>] ... Set boolean option to true
7544 B<O> [I<opt>B<?>] Query options
7545 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7546 Set options. Use quotes if spaces in value.
7547 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7548 I<pager> program for output of \"|cmd\";
7549 I<tkRunning> run Tk while prompting (with ReadLine);
7550 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7551 I<inhibit_exit> Allows stepping off the end of the script.
7552 I<ImmediateStop> Debugger should stop as early as possible.
7553 I<RemotePort> Remote hostname:port for remote debugging
7554 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7555 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7556 I<compactDump>, I<veryCompact> change style of array and hash dump;
7557 I<globPrint> whether to print contents of globs;
7558 I<DumpDBFiles> dump arrays holding debugged files;
7559 I<DumpPackages> dump symbol tables of packages;
7560 I<DumpReused> dump contents of \"reused\" addresses;
7561 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7562 I<bareStringify> Do not print the overload-stringified value;
7563 Other options include:
7564 I<PrintRet> affects printing of return value after B<r> command,
7565 I<frame> affects printing messages on subroutine entry/exit.
7566 I<AutoTrace> affects printing messages on possible breaking points.
7567 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7568 I<ornaments> affects screen appearance of the command line.
7569 I<CreateTTY> bits control attempts to create a new TTY on events:
7570 1: on fork() 2: debugger is started inside debugger
7572 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7573 You can put additional initialization options I<TTY>, I<noTTY>,
7574 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7575 B<R> after you set them).
7577 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7578 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7579 B<h h> Summary of debugger commands.
7580 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7581 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7582 Set B<\$DB::doccmd> to change viewer.
7584 Type '|h' for a paged display if this was too hard to read.
7586 "; # Fix balance of vi % matching: }}}}
7588 # note: tabs in the following section are not-so-helpful
7589 $pre580_summary = <<"END_SUM";
7590 I<List/search source lines:> I<Control script execution:>
7591 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7592 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7593 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
7594 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7595 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7596 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
7597 I<Debugger controls:> B<L> List break/watch/actions
7598 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7599 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7600 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
7601 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7602 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
7603 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
7604 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7605 B<q> or B<^D> Quit B<R> Attempt a restart
7606 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7607 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7608 B<p> I<expr> Print expression (uses script's current package).
7609 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7610 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7611 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
7612 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7613 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7616 # ')}}; # Fix balance of vi % matching
7618 } ## end sub sethelp
7620 =head2 C<print_help()>
7622 Most of what C<print_help> does is just text formatting. It finds the
7623 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
7624 terminal control characters to simulate them (courtesy of
7625 C<Term::ReadLine::TermCap>).
7632 # Restore proper alignment destroyed by eeevil I<> and B<>
7633 # ornaments: A pox on both their houses!
7635 # A help command will have everything up to and including
7636 # the first tab sequence padded into a field 16 (or if indented 20)
7637 # wide. If it's wider than that, an extra space will be added.
7639 ^ # only matters at start of line
7640 ( \040{4} | \t )* # some subcommands are indented
7641 ( < ? # so <CR> works
7642 [BI] < [^\t\n] + ) # find an eeevil ornament
7643 ( \t+ ) # original separation, discarded
7644 ( .* ) # this will now start (no earlier) than
7647 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
7648 my $clean = $command;
7649 $clean =~ s/[BI]<([^>]*)>/$1/g;
7651 # replace with this whole string:
7652 ($leadwhite ? " " x 4 : "")
7654 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
7659 s{ # handle bold ornaments
7660 B < ( [^>] + | > ) >
7662 $Term::ReadLine::TermCap::rl_term_set[2]
7664 . $Term::ReadLine::TermCap::rl_term_set[3]
7667 s{ # handle italic ornaments
7668 I < ( [^>] + | > ) >
7670 $Term::ReadLine::TermCap::rl_term_set[0]
7672 . $Term::ReadLine::TermCap::rl_term_set[1]
7677 } ## end sub print_help
7681 This routine does a lot of gyrations to be sure that the pager is C<less>.
7682 It checks for C<less> masquerading as C<more> and records the result in
7683 C<$fixed_less> so we don't have to go through doing the stats again.
7687 use vars qw($fixed_less);
7691 # We already know if this is set.
7692 return if $fixed_less;
7694 # Pager is less for sure.
7695 my $is_less = $pager =~ /\bless\b/;
7696 if ( $pager =~ /\bmore\b/ ) {
7698 # Nope, set to more. See what's out there.
7699 my @st_more = stat('/usr/bin/more');
7700 my @st_less = stat('/usr/bin/less');
7702 # is it really less, pretending to be more?
7705 && $st_more[0] == $st_less[0]
7706 && $st_more[1] == $st_less[1];
7707 } ## end if ($pager =~ /\bmore\b/)
7709 # changes environment!
7710 # 'r' added so we don't do (slow) stats again.
7711 $fixed_less = 1 if $is_less;
7712 } ## end sub fix_less
7714 =head1 DIE AND WARN MANAGEMENT
7718 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
7719 to debug a debugger problem.
7721 It does its best to report the error that occurred, and then forces the
7722 program, debugger, and everything to die.
7728 # No entry/exit messages.
7731 # No return value prints.
7734 # set the abort signal handling to the default (just terminate).
7735 $SIG{'ABRT'} = 'DEFAULT';
7737 # If we enter the signal handler recursively, kill myself with an
7738 # abort signal (so we just terminate).
7739 kill 'ABRT', $$ if $panic++;
7741 # If we can show detailed info, do so.
7742 if ( defined &Carp::longmess ) {
7744 # Don't recursively enter the warn handler, since we're carping.
7745 local $SIG{__WARN__} = '';
7747 # Skip two levels before reporting traceback: we're skipping
7748 # mydie and confess.
7749 local $Carp::CarpLevel = 2; # mydie + confess
7751 # Tell us all about it.
7752 &warn( Carp::longmess("Signal @_") );
7755 # No Carp. Tell us about the signal as best we can.
7758 print $DB::OUT "Got signal @_\n";
7763 } ## end sub diesignal
7767 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
7768 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
7774 # No entry/exit trace.
7777 # No return value printing.
7780 # Turn off warn and die handling to prevent recursive entries to this
7782 local $SIG{__WARN__} = '';
7783 local $SIG{__DIE__} = '';
7785 # Load Carp if we can. If $^S is false (current thing being compiled isn't
7786 # done yet), we may not be able to do a require.
7787 eval { require Carp }
7788 if defined $^S; # If error/warning during compilation,
7789 # require may be broken.
7791 # Use the core warn() unless Carp loaded OK.
7793 "\nCannot print stack trace, load with -MCarp option to see stack" ),
7795 unless defined &Carp::longmess;
7797 # Save the current values of $single and $trace, and then turn them off.
7798 my ( $mysingle, $mytrace ) = ( $single, $trace );
7802 # We can call Carp::longmess without its being "debugged" (which we
7803 # don't want - we just want to use it!). Capture this for later.
7804 my $mess = Carp::longmess(@_);
7806 # Restore $single and $trace to their original values.
7807 ( $single, $trace ) = ( $mysingle, $mytrace );
7809 # Use the debugger's own special way of printing warnings to print
7810 # the stack trace message.
7816 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
7817 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
7818 single stepping and tracing during the call to C<Carp::longmess> to avoid
7819 debugging it - we just want to use it.
7821 If C<dieLevel> is zero, we let the program being debugged handle the
7822 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
7823 the debugger takes over all exception handling, printing a backtrace and
7824 displaying the exception via its C<dbwarn()> routine.
7831 local $SIG{__DIE__} = '';
7832 local $SIG{__WARN__} = '';
7836 if ( $dieLevel > 2 ) {
7837 local $SIG{__WARN__} = \&dbwarn;
7838 &warn(@_); # Yell no matter what
7841 if ( $dieLevel < 2 ) {
7842 die @_ if $^S; # in eval propagate
7845 # The code used to check $^S to see if compilation of the current thing
7846 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
7847 eval { require Carp };
7850 "\nCannot print stack trace, load with -MCarp option to see stack" )
7851 unless defined &Carp::longmess;
7853 # We do not want to debug this chunk (automatic disabling works
7854 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
7855 # get the stack trace from Carp::longmess (if possible), restore $signal
7856 # and $trace, and then die with the stack trace.
7857 my ( $mysingle, $mytrace ) = ( $single, $trace );
7863 package Carp; # Do not include us in the list
7864 eval { $mess = Carp::longmess(@_); };
7866 ( $single, $trace ) = ( $mysingle, $mytrace );
7870 =head2 C<warnlevel()>
7872 Set the C<$DB::warnLevel> variable that stores the value of the
7873 C<warnLevel> option. Calling C<warnLevel()> with a positive value
7874 results in the debugger taking over all warning handlers. Setting
7875 C<warnLevel> to zero leaves any warning handlers set up by the program
7876 being debugged in place.
7882 my $prevwarn = $SIG{__WARN__} unless $warnLevel;
7885 $SIG{__WARN__} = \&DB::dbwarn;
7888 $SIG{__WARN__} = $prevwarn;
7890 undef $SIG{__WARN__};
7894 } ## end sub warnLevel
7898 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
7899 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
7900 zero lets you use your own C<die()> handler.
7907 my $prevdie = $SIG{__DIE__} unless $dieLevel;
7911 # Always set it to dbdie() for non-zero values.
7912 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
7914 # No longer exists, so don't try to use it.
7915 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
7917 # If we've finished initialization, mention that stack dumps
7918 # are enabled, If dieLevel is 1, we won't stack dump if we die
7920 print $OUT "Stack dump during die enabled",
7921 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
7924 # XXX This is probably obsolete, given that diehard() is gone.
7925 print $OUT "Dump printed too.\n" if $dieLevel > 2;
7926 } ## end if ($dieLevel)
7928 # Put the old one back if there was one.
7930 $SIG{__DIE__} = $prevdie;
7931 print $OUT "Default die handler restored.\n";
7933 undef $SIG{__DIE__};
7934 print $OUT "Die handler removed.\n";
7938 } ## end sub dieLevel
7940 =head2 C<signalLevel>
7942 Number three in a series: set C<signalLevel> to zero to keep your own
7943 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
7944 takes over and handles them with C<DB::diesignal()>.
7950 my $prevsegv = $SIG{SEGV} unless $signalLevel;
7951 my $prevbus = $SIG{BUS} unless $signalLevel;
7952 $signalLevel = shift;
7954 $SIG{SEGV} = \&DB::diesignal;
7955 $SIG{BUS} = \&DB::diesignal;
7958 $SIG{SEGV} = $prevsegv;
7959 $SIG{BUS} = $prevbus;
7963 } ## end sub signalLevel
7965 =head1 SUBROUTINE DECODING SUPPORT
7967 These subroutines are used during the C<x> and C<X> commands to try to
7968 produce as much information as possible about a code reference. They use
7969 L<Devel::Peek> to try to find the glob in which this code reference lives
7970 (if it does) - this allows us to actually code references which correspond
7971 to named subroutines (including those aliased via glob assignment).
7973 =head2 C<CvGV_name()>
7975 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
7976 via that routine. If this fails, return the reference again (when the
7977 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
7983 my $name = CvGV_name_or_bust($in);
7984 defined $name ? $name : $in;
7987 =head2 C<CvGV_name_or_bust> I<coderef>
7989 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
7990 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
7991 find a glob for this ref.
7993 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
7997 use vars qw($skipCvGV);
7999 sub CvGV_name_or_bust {
8001 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
8002 return unless ref $in;
8003 $in = \&$in; # Hard reference...
8004 eval { require Devel::Peek; 1 } or return;
8005 my $gv = Devel::Peek::CvGV($in) or return;
8006 *$gv{PACKAGE} . '::' . *$gv{NAME};
8007 } ## end sub CvGV_name_or_bust
8011 A utility routine used in various places; finds the file where a subroutine
8012 was defined, and returns that filename and a line-number range.
8014 Tries to use C<@sub> first; if it can't find it there, it tries building a
8015 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
8016 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
8017 this way, it brute-force searches C<%sub>, checking for identical references.
8024 return unless defined &$subr;
8025 my $name = CvGV_name_or_bust($subr);
8027 $data = $sub{$name} if defined $name;
8028 return $data if defined $data;
8031 $subr = \&$subr; # Hard reference
8034 $s = $_, last if $subr eq \&$_;
8038 } ## end sub find_sub
8042 A subroutine that uses the utility function C<methods_via> to find all the
8043 methods in the class corresponding to the current reference and in
8052 # Figure out the class - either this is the class or it's a reference
8053 # to something blessed into that class.
8055 $class = ref $class if ref $class;
8059 # Show the methods that this class has.
8060 methods_via( $class, '', 1 );
8062 # Show the methods that UNIVERSAL has.
8063 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
8064 } ## end sub methods
8066 =head2 C<methods_via($class, $prefix, $crawl_upward)>
8068 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
8069 all the parent class methods. C<$class> is the name of the next class to
8070 try; C<$prefix> is the message prefix, which gets built up as we go up the
8071 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
8072 higher in the C<@ISA> tree, 0 if we should stop.
8078 # If we've processed this class already, just quit.
8080 return if $seen{$class}++;
8082 # This is a package that is contributing the methods we're about to print.
8084 my $prepend = $prefix ? "via $prefix: " : '';
8087 # Extract from all the symbols in this class.
8088 my $class_ref = do { no strict "refs"; \%{$class . '::'} };
8089 while (my ($name, $glob) = each %$class_ref) {
8090 # references directly in the symbol table are Proxy Constant
8091 # Subroutines, and are by their very nature defined
8092 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8093 # to a subroutine reference, which can be tested by defined.
8094 # $glob might also be the value -1 (from sub foo;)
8095 # or (say) '$$' (from sub foo ($$);)
8096 # \$glob will be SCALAR in both cases.
8097 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8098 && !$seen{$name}++) {
8099 push @to_print, "$prepend$name\n";
8106 print $DB::OUT $_ foreach sort @to_print;
8109 # If the $crawl_upward argument is false, just quit here.
8110 return unless shift;
8112 # $crawl_upward true: keep going up the tree.
8113 # Find all the classes this one is a subclass of.
8114 my $class_ISA_ref = do { no strict "refs"; \@{"${class}::ISA"} };
8115 for my $name ( @$class_ISA_ref ) {
8117 # Set up the new prefix.
8118 $prepend = $prefix ? $prefix . " -> $name" : $name;
8120 # Crawl up the tree and keep trying to crawl up.
8121 methods_via( $name, $prepend, 1 );
8123 } ## end sub methods_via
8125 =head2 C<setman> - figure out which command to use to show documentation
8127 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8132 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|NetWare)\z/s
8133 ? "man" # O Happy Day!
8134 : "perldoc"; # Alas, poor unfortunates
8137 =head2 C<runman> - run the appropriate command to show documentation
8139 Accepts a man page name; runs the appropriate command to display it (set up
8140 during debugger initialization). Uses C<DB::system> to avoid mucking up the
8141 program's STDIN and STDOUT.
8148 &system("$doccmd $doccmd");
8152 # this way user can override, like with $doccmd="man -Mwhatever"
8153 # or even just "man " to disable the path check.
8154 unless ( $doccmd eq 'man' ) {
8155 &system("$doccmd $page");
8159 $page = 'perl' if lc($page) eq 'help';
8162 my $man1dir = $Config::Config{'man1dir'};
8163 my $man3dir = $Config::Config{'man3dir'};
8164 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8166 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8167 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8168 chop $manpath if $manpath;
8170 # harmless if missing, I figure
8171 my $oldpath = $ENV{MANPATH};
8172 $ENV{MANPATH} = $manpath if $manpath;
8173 my $nopathopt = $^O =~ /dunno what goes here/;
8178 # I just *know* there are men without -M
8179 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8184 unless ( $page =~ /^perl\w/ ) {
8185 # do it this way because its easier to slurp in to keep up to date - clunky though.
8320 if (grep { $page eq $_ } @pods) {
8322 CORE::system( $doccmd,
8323 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8325 } ## end if (grep { $page eq $_...
8326 } ## end unless ($page =~ /^perl\w/)
8327 } ## end if (CORE::system($doccmd...
8328 if ( defined $oldpath ) {
8329 $ENV{MANPATH} = $manpath;
8332 delete $ENV{MANPATH};
8336 #use Carp; # This did break, left for debugging
8338 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
8340 Because of the way the debugger interface to the Perl core is designed, any
8341 debugger package globals that C<DB::sub()> requires have to be defined before
8342 any subroutines can be called. These are defined in the second C<BEGIN> block.
8344 This block sets things up so that (basically) the world is sane
8345 before the debugger starts executing. We set up various variables that the
8346 debugger has to have set up before the Perl core starts running:
8352 The debugger's own filehandles (copies of STD and STDOUT for now).
8356 Characters for shell escapes, the recall command, and the history command.
8360 The maximum recursion depth.
8364 The size of a C<w> command's window.
8368 The before-this-line context to be printed in a C<v> (view a window around this line) command.
8372 The fact that we're not in a sub at all right now.
8376 The default SIGINT handler for the debugger.
8380 The appropriate value of the flag in C<$^D> that says the debugger is running
8384 The current debugger recursion level
8388 The list of postponed items and the C<$single> stack (XXX define this)
8392 That we want no return values and no subroutine entry/exit trace.
8398 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
8400 use vars qw($db_stop);
8402 BEGIN { # This does not compile, alas. (XXX eh?)
8403 $IN = \*STDIN; # For bugs before DB::OUT has been opened
8404 $OUT = \*STDERR; # For errors before DB::OUT has been opened
8406 # Define characters used by command parsing.
8407 $sh = '!'; # Shell escape (does not work)
8408 $rc = ','; # Recall command (does not work)
8409 @hist = ('?'); # Show history (does not work)
8410 @truehist = (); # Can be saved for replay (per session)
8412 # This defines the point at which you get the 'deep recursion'
8413 # warning. It MUST be defined or the debugger will not load.
8416 # Number of lines around the current one that are shown in the
8420 # How much before-the-current-line context the 'v' command should
8421 # use in calculating the start of the window it will display.
8424 # We're not in any sub yet, but we need this to be a defined value.
8427 # Set up the debugger's interrupt handler. It simply sets a flag
8428 # ($signal) that DB::DB() will check before each command is executed.
8429 $SIG{INT} = \&DB::catch;
8431 # The following lines supposedly, if uncommented, allow the debugger to
8432 # debug itself. Perhaps we can try that someday.
8433 # This may be enabled to debug debugger:
8434 #$warnLevel = 1 unless defined $warnLevel;
8435 #$dieLevel = 1 unless defined $dieLevel;
8436 #$signalLevel = 1 unless defined $signalLevel;
8438 # This is the flag that says "a debugger is running, please call
8439 # DB::DB and DB::sub". We will turn it on forcibly before we try to
8440 # execute anything in the user's context, because we always want to
8442 $db_stop = 0; # Compiler warning ...
8443 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
8445 # This variable records how many levels we're nested in debugging. Used
8446 # Used in the debugger prompt, and in determining whether it's all over or
8448 $level = 0; # Level of recursive debugging
8450 # "Triggers bug (?) in perl if we postpone this until runtime."
8451 # XXX No details on this yet, or whether we should fix the bug instead
8452 # of work around it. Stay tuned.
8455 # Used to track the current stack depth using the auto-stacked-variable
8457 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
8459 # Don't print return values on exiting a subroutine.
8462 # No extry/exit tracing.
8467 BEGIN { $^W = $ini_warn; } # Switch warnings back
8469 =head1 READLINE SUPPORT - COMPLETION FUNCTION
8473 C<readline> support - adds command completion to basic C<readline>.
8475 Returns a list of possible completions to C<readline> when invoked. C<readline>
8476 will print the longest common substring following the text already entered.
8478 If there is only a single possible completion, C<readline> will use it in full.
8480 This code uses C<map> and C<grep> heavily to create lists of possible
8481 completion. Think LISP in this section.
8487 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
8488 # $text is the text to be completed.
8489 # $line is the incoming line typed by the user.
8490 # $start is the start of the text to be completed in the incoming line.
8491 my ( $text, $line, $start ) = @_;
8493 # Save the initial text.
8494 # The search pattern is current package, ::, extract the next qualifier
8495 # Prefix and pack are set to undef.
8496 my ( $itext, $search, $prefix, $pack ) =
8497 ( $text, "^\Q${package}::\E([^:]+)\$" );
8499 =head3 C<b postpone|compile>
8505 Find all the subroutines that might match in this package
8509 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
8513 Include all the rest of the subs that are known
8517 C<grep> out the ones that match the text we have so far
8521 Return this as the list of possible completions
8527 return sort grep /^\Q$text/, ( keys %sub ),
8528 qw(postpone load compile), # subroutines
8529 ( map { /$search/ ? ($1) : () } keys %sub )
8530 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
8534 Get all the possible files from C<@INC> as it currently stands and
8535 select the ones that match the text so far.
8539 return sort grep /^\Q$text/, values %INC # files
8540 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
8542 =head3 C<V> (list variable) and C<m> (list modules)
8544 There are two entry points for these commands:
8546 =head4 Unqualified package names
8548 Get the top-level packages and grab everything that matches the text
8549 so far. For each match, recursively complete the partial packages to
8550 get all possible matching packages. Return this sorted list.
8554 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8555 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
8556 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
8558 =head4 Qualified package names
8560 Take a partially-qualified package and find all subpackages for it
8561 by getting all the subpackages for the package so far, matching all
8562 the subpackages against the text, and discarding all of them which
8563 start with 'main::'. Return this list.
8567 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8568 grep !/^main::/, grep /^\Q$text/,
8569 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () }
8570 do { no strict 'refs'; keys %{ $prefix . '::' } }
8571 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
8572 and $text =~ /^(.*[^:])::?(\w*)$/
8575 =head3 C<f> - switch files
8577 Here, we want to get a fully-qualified filename for the C<f> command.
8582 =item 1. The original source file itself
8584 =item 2. A file from C<@INC>
8586 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
8592 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
8593 # We might possibly want to switch to an eval (which has a "filename"
8594 # like '(eval 9)'), so we may need to clean up the completion text
8595 # before proceeding.
8596 $prefix = length($1) - length($text);
8601 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
8602 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
8603 out of C<%main::>, add the initial source file, and extract the ones that
8604 match the completion text so far.
8609 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
8611 } ## end if ($line =~ /^\|*f\s+(.*)/)
8613 =head3 Subroutine name completion
8615 We look through all of the defined subs (the keys of C<%sub>) and
8616 return both all the possible matches to the subroutine name plus
8617 all the matches qualified to the current package.
8621 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
8622 $text = substr $text, 1;
8624 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
8626 map { /$search/ ? ($1) : () }
8629 } ## end if ((substr $text, 0, ...
8631 =head3 Scalar, array, and hash completion: partially qualified package
8633 Much like the above, except we have to do a little more cleanup:
8637 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
8645 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
8649 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
8655 Figure out the prefix vs. what needs completing.
8659 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
8666 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
8670 my @out = map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
8677 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.
8681 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8682 return db_complete( $out[0], $line, $start );
8685 # Return the list of possibles.
8688 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
8694 =head3 Symbol completion: current package or package C<main>.
8698 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
8705 If it's C<main>, delete main to just get C<::> leading.
8709 $pack = ( $package eq 'main' ? '' : $package ) . '::';
8715 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
8719 $prefix = substr $text, 0, 1;
8720 $text = substr $text, 1;
8728 We look for the lexical scope above DB::DB and auto-complete lexical variables
8729 if PadWalker could be loaded.
8733 if (not $text =~ /::/ and eval { require PadWalker } ) {
8736 my @info = caller($level);
8740 last if $info[3] eq 'DB::DB';
8743 my $lexicals = PadWalker::peek_my($level);
8744 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
8752 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
8756 push @out, map "$prefix$_", grep /^\Q$text/,
8757 ( grep /^_?[a-zA-Z]/, keys %$pack ),
8758 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
8762 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
8768 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8769 return db_complete( $out[0], $line, $start );
8772 # Return the list of possibles.
8774 } ## end if ($text =~ /^[\$@%]/)
8778 We use C<option_val()> to look up the current value of the option. If there's
8779 only a single value, we complete the command in such a way that it is a
8780 complete command for setting the option in question. If there are multiple
8781 possible values, we generate a command consisting of the option plus a trailing
8782 question mark, which, if executed, will list the current value of the option.
8786 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
8787 { # Options after space
8788 # We look for the text to be matched in the list of possible options,
8789 # and fetch the current value.
8790 my @out = grep /^\Q$text/, @options;
8791 my $val = option_val( $out[0], undef );
8793 # Set up a 'query option's value' command.
8795 if ( not defined $val or $val =~ /[\n\r]/ ) {
8797 # There's really nothing else we can do.
8800 # We have a value. Create a proper option-setting command.
8801 elsif ( $val =~ /\s/ ) {
8803 # XXX This may be an extraneous variable.
8806 # We'll want to quote the string (because of the embedded
8807 # whtespace), but we want to make sure we don't end up with
8808 # mismatched quote characters. We try several possibilities.
8809 foreach my $l ( split //, qq/\"\'\#\|/ ) {
8811 # If we didn't find this quote character in the value,
8812 # quote it using this quote character.
8813 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
8815 } ## end elsif ($val =~ /\s/)
8817 # Don't need any quotes.
8822 # If there were multiple possible values, return '? ', which
8823 # makes the command into a query command. If there was just one,
8824 # have readline append that.
8825 $rl_attribs->{completer_terminator_character} =
8826 ( @out == 1 ? $out : '? ' );
8828 # Return list of possibilities.
8830 } ## end if ((substr $line, 0, ...
8832 =head3 Filename completion
8834 For entering filenames. We simply call C<readline>'s C<filename_list()>
8835 method with the completion text to get the possible completions.
8839 return $term->filename_list($text); # filenames
8841 } ## end sub db_complete
8843 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
8845 Functions that possibly ought to be somewhere else.
8855 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n";
8860 If we have $ini_pids, save it in the environment; else remove it from the
8861 environment. Used by the C<R> (restart) command.
8866 if ( defined($ini_pids) ) {
8867 $ENV{PERLDB_PIDS} = $ini_pids;
8870 delete( $ENV{PERLDB_PIDS} );
8872 } ## end sub clean_ENV
8874 # PERLDBf_... flag names from perl.h
8875 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
8878 %DollarCaretP_flags = (
8879 PERLDBf_SUB => 0x01, # Debug sub enter/exit
8880 PERLDBf_LINE => 0x02, # Keep line #
8881 PERLDBf_NOOPT => 0x04, # Switch off optimizations
8882 PERLDBf_INTER => 0x08, # Preserve more data
8883 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
8884 PERLDBf_SINGLE => 0x20, # Start with single-step on
8885 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
8886 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
8887 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
8888 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
8889 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
8890 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
8892 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
8893 # doesn't need to set it. It's provided for the benefit of profilers and
8894 # other code analysers.
8896 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
8899 sub parse_DollarCaretP_flags {
8904 foreach my $f ( split /\s*\|\s*/, $flags ) {
8906 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
8909 elsif ( $f =~ /^(\d+)$/ ) {
8912 elsif ( $f =~ /^DEFAULT$/i ) {
8913 $value = $DollarCaretP_flags{PERLDB_ALL};
8916 $f =~ /^(?:PERLDBf_)?(.*)$/i;
8917 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
8918 unless ( defined $value ) {
8920 "Unrecognized \$^P flag '$f'!\n",
8921 "Acceptable flags are: "
8922 . join( ', ', sort keys %DollarCaretP_flags ),
8923 ", and hexadecimal and decimal numbers.\n"
8933 sub expand_DollarCaretP_flags {
8934 my $DollarCaretP = shift;
8937 my $n = ( 1 << $_ );
8938 ( $DollarCaretP & $n )
8939 ? ( $DollarCaretP_flags_r{$n}
8940 || sprintf( '0x%x', $n ) )
8944 return @bits ? join( '|', @bits ) : 0;
8951 Rerun the current session to:
8953 rerun current position
8955 rerun 4 command number 4
8957 rerun -4 current command minus 4 (go back 4 steps)
8959 Whether this always makes sense, in the current context is unknowable, and is
8960 in part left as a useful exercise for the reader. This sub returns the
8961 appropriate arguments to rerun the current session.
8968 pop(@truehist); # strim
8969 unless (defined $truehist[$i]) {
8970 print "Unable to return to non-existent command: $i\n";
8972 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
8973 my @temp = @truehist; # store
8974 push(@DB::typeahead, @truehist); # saved
8975 @truehist = @hist = (); # flush
8976 @args = &restart(); # setup
8977 &get_list("PERLDB_HIST"); # clean
8978 &set_list("PERLDB_HIST", @temp); # reset
8985 Restarting the debugger is a complex operation that occurs in several phases.
8986 First, we try to reconstruct the command line that was used to invoke Perl
8992 # I may not be able to resurrect you, but here goes ...
8994 "Warning: some settings and command-line options may be lost!\n";
8995 my ( @script, @flags, $cl );
8997 # If warn was on before, turn it on again.
8998 push @flags, '-w' if $ini_warn;
9000 # Rebuild the -I flags that were on the initial
9003 push @flags, '-I', $_;
9006 # Turn on taint if it was on before.
9007 push @flags, '-T' if ${^TAINT};
9009 # Arrange for setting the old INC:
9010 # Save the current @init_INC in the environment.
9011 set_list( "PERLDB_INC", @ini_INC );
9013 # If this was a perl one-liner, go to the "file"
9014 # corresponding to the one-liner read all the lines
9015 # out of it (except for the first one, which is going
9016 # to be added back on again when 'perl -d' runs: that's
9017 # the 'require perl5db.pl;' line), and add them back on
9018 # to the command line to be executed.
9020 my $lines = *{$main::{'_<-e'}}{ARRAY};
9021 for ( 1 .. $#$lines ) { # The first line is PERL5DB
9022 chomp( $cl = $lines->[$_] );
9023 push @script, '-e', $cl;
9025 } ## end if ($0 eq '-e')
9027 # Otherwise we just reuse the original name we had
9035 After the command line has been reconstructed, the next step is to save
9036 the debugger's status in environment variables. The C<DB::set_list> routine
9037 is used to save aggregate variables (both hashes and arrays); scalars are
9038 just popped into environment variables directly.
9042 # If the terminal supported history, grab it and
9043 # save that in the environment.
9044 set_list( "PERLDB_HIST",
9045 $term->Features->{getHistory}
9049 # Find all the files that were visited during this
9050 # session (i.e., the debugger had magic hashes
9051 # corresponding to them) and stick them in the environment.
9052 my @had_breakpoints = keys %had_breakpoints;
9053 set_list( "PERLDB_VISITED", @had_breakpoints );
9055 # Save the debugger options we chose.
9056 set_list( "PERLDB_OPT", %option );
9057 # set_list( "PERLDB_OPT", options2remember() );
9059 # Save the break-on-loads.
9060 set_list( "PERLDB_ON_LOAD", %break_on_load );
9064 The most complex part of this is the saving of all of the breakpoints. They
9065 can live in an awful lot of places, and we have to go through all of them,
9066 find the breakpoints, and then save them in the appropriate environment
9067 variable via C<DB::set_list>.
9071 # Go through all the breakpoints and make sure they're
9074 for ( 0 .. $#had_breakpoints ) {
9076 # We were in this file.
9077 my $file = $had_breakpoints[$_];
9079 # Grab that file's magic line hash.
9080 *dbline = $main::{ '_<' . $file };
9082 # Skip out if it doesn't exist, or if the breakpoint
9083 # is in a postponed file (we'll do postponed ones
9085 next unless %dbline or $postponed_file{$file};
9087 # In an eval. This is a little harder, so we'll
9088 # do more processing on that below.
9089 ( push @hard, $file ), next
9090 if $file =~ /^\(\w*eval/;
9092 # XXX I have no idea what this is doing. Yet.
9094 @add = %{ $postponed_file{$file} }
9095 if $postponed_file{$file};
9097 # Save the list of all the breakpoints for this file.
9098 set_list( "PERLDB_FILE_$_", %dbline, @add );
9100 # Serialize the extra data %breakpoints_data hash.
9102 set_list( "PERLDB_FILE_ENABLED_$_",
9103 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 }
9104 sort { $a <=> $b } keys(%dbline)
9106 } ## end for (0 .. $#had_breakpoints)
9108 # The breakpoint was inside an eval. This is a little
9109 # more difficult. XXX and I don't understand it.
9111 # Get over to the eval in question.
9112 *dbline = $main::{ '_<' . $_ };
9113 my ( $quoted, $sub, %subs, $line ) = quotemeta $_;
9114 for $sub ( keys %sub ) {
9115 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
9116 $subs{$sub} = [ $1, $2 ];
9120 "No subroutines in $_, ignoring breakpoints.\n";
9123 LINES: for $line ( keys %dbline ) {
9125 # One breakpoint per sub only:
9126 my ( $offset, $sub, $found );
9127 SUBS: for $sub ( keys %subs ) {
9130 $line # Not after the subroutine
9132 not defined $offset # Not caught
9138 $offset = $line - $subs{$sub}->[0];
9139 $offset = "+$offset", last SUBS
9141 } ## end if ($subs{$sub}->[1] >=...
9142 } ## end for $sub (keys %subs)
9143 if ( defined $offset ) {
9144 $postponed{$found} =
9145 "break $offset if $dbline{$line}";
9149 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
9151 } ## end for $line (keys %dbline)
9152 } ## end for (@hard)
9154 # Save the other things that don't need to be
9156 set_list( "PERLDB_POSTPONE", %postponed );
9157 set_list( "PERLDB_PRETYPE", @$pretype );
9158 set_list( "PERLDB_PRE", @$pre );
9159 set_list( "PERLDB_POST", @$post );
9160 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9162 # We are officially restarting.
9163 $ENV{PERLDB_RESTART} = 1;
9165 # We are junking all child debuggers.
9166 delete $ENV{PERLDB_PIDS}; # Restore ini state
9168 # Set this back to the initial pid.
9169 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9173 After all the debugger status has been saved, we take the command we built up
9174 and then return it, so we can C<exec()> it. The debugger will spot the
9175 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9176 from the environment.
9180 # And run Perl again. Add the "-d" flag, all the
9181 # flags we built up, the script (whether a one-liner
9182 # or a file), add on the -emacs flag for a slave editor,
9183 # and then the old arguments.
9185 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9191 =head1 END PROCESSING - THE C<END> BLOCK
9193 Come here at the very end of processing. We want to go into a
9194 loop where we allow the user to enter commands and interact with the
9195 debugger, but we don't want anything else to execute.
9197 First we set the C<$finished> variable, so that some commands that
9198 shouldn't be run after the end of program quit working.
9200 We then figure out whether we're truly done (as in the user entered a C<q>
9201 command, or we finished execution while running nonstop). If we aren't,
9202 we set C<$single> to 1 (causing the debugger to get control again).
9204 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9205 message and returns control to the debugger. Repeat.
9207 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9208 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9209 break, run to completion.).
9214 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9215 $fall_off_end = 1 unless $inhibit_exit;
9217 # Do not stop in at_exit() and destructors on exit:
9218 if ($fall_off_end or $runnonstop) {
9222 DB::fake::at_exit();
9226 =head1 PRE-5.8 COMMANDS
9228 Some of the commands changed function quite a bit in the 5.8 command
9229 realignment, so much so that the old code had to be replaced completely.
9230 Because we wanted to retain the option of being able to go back to the
9231 former command set, we moved the old code off to this section.
9233 There's an awful lot of duplicated code here. We've duplicated the
9234 comments to keep things clear.
9238 Does nothing. Used to I<turn off> commands.
9242 sub cmd_pre580_null {
9247 =head2 Old C<a> command.
9249 This version added actions if you supplied them, and deleted them
9258 # Argument supplied. Add the action.
9259 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9261 # If the line isn't there, use the current line.
9262 my $i = $1 || $line;
9265 # If there is an action ...
9268 # ... but the line isn't breakable, skip it.
9269 if ( $dbline[$i] == 0 ) {
9270 print $OUT "Line $i may not have an action.\n";
9274 # ... and the line is breakable:
9275 # Mark that there's an action in this file.
9276 $had_breakpoints{$filename} |= 2;
9278 # Delete any current action.
9279 $dbline{$i} =~ s/\0[^\0]*//;
9281 # Add the new action, continuing the line as needed.
9282 $dbline{$i} .= "\0" . action($j);
9284 } ## end if (length $j)
9286 # No action supplied.
9289 # Delete the action.
9290 $dbline{$i} =~ s/\0[^\0]*//;
9292 # Mark as having no break or action if nothing's left.
9293 delete $dbline{$i} if $dbline{$i} eq '';
9295 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9296 } ## end sub cmd_pre580_a
9298 =head2 Old C<b> command
9310 if ( $cmd =~ /^load\b\s*(.*)/ ) {
9316 # b compile|postpone <some sub> [<condition>]
9317 # The interpreter actually traps this one for us; we just put the
9318 # necessary condition in the %postponed hash.
9319 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
9321 # Capture the condition if there is one. Make it true if none.
9322 my $cond = length $3 ? $3 : '1';
9324 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
9325 # if it was 'compile'.
9326 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
9328 # De-Perl4-ify the name - ' separators to ::.
9329 $subname =~ s/\'/::/g;
9331 # Qualify it into the current package unless it's already qualified.
9332 $subname = "${package}::" . $subname
9333 unless $subname =~ /::/;
9335 # Add main if it starts with ::.
9336 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
9338 # Save the break type for this sub.
9339 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
9340 } ## end elsif ($cmd =~ ...
9342 # b <sub name> [<condition>]
9343 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
9345 my $cond = length $2 ? $2 : '1';
9346 &cmd_b_sub( $subname, $cond );
9348 # b <line> [<condition>].
9349 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9350 my $i = $1 || $dbline;
9351 my $cond = length $2 ? $2 : '1';
9352 &cmd_b_line( $i, $cond );
9354 } ## end sub cmd_pre580_b
9356 =head2 Old C<D> command.
9358 Delete all breakpoints unconditionally.
9365 if ( $cmd =~ /^\s*$/ ) {
9366 print $OUT "Deleting all breakpoints...\n";
9368 # %had_breakpoints lists every file that had at least one
9371 for $file ( keys %had_breakpoints ) {
9373 # Switch to the desired file temporarily.
9374 local *dbline = $main::{ '_<' . $file };
9379 # For all lines in this file ...
9380 for ( my $i = 1 ; $i <= $max ; $i++ ) {
9382 # If there's a breakpoint or action on this line ...
9383 if ( defined $dbline{$i} ) {
9385 # ... remove the breakpoint.
9386 $dbline{$i} =~ s/^[^\0]+//;
9387 if ( $dbline{$i} =~ s/^\0?$// ) {
9389 # Remove the entry altogether if no action is there.
9392 } ## end if (defined $dbline{$i...
9393 } ## end for ($i = 1 ; $i <= $max...
9395 # If, after we turn off the "there were breakpoints in this file"
9396 # bit, the entry in %had_breakpoints for this file is zero,
9397 # we should remove this file from the hash.
9398 if ( not $had_breakpoints{$file} &= ~1 ) {
9399 delete $had_breakpoints{$file};
9401 } ## end for $file (keys %had_breakpoints)
9403 # Kill off all the other breakpoints that are waiting for files that
9404 # haven't been loaded yet.
9406 undef %postponed_file;
9407 undef %break_on_load;
9408 } ## end if ($cmd =~ /^\s*$/)
9409 } ## end sub cmd_pre580_D
9411 =head2 Old C<h> command
9413 Print help. Defaults to printing the long-form help; the 5.8 version
9414 prints the summary by default.
9422 # Print the *right* help, long format.
9423 if ( $cmd =~ /^\s*$/ ) {
9424 print_help($pre580_help);
9427 # 'h h' - explicitly-requested summary.
9428 elsif ( $cmd =~ /^h\s*/ ) {
9429 print_help($pre580_summary);
9432 # Find and print a command's help.
9433 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
9434 my $asked = $1; # for proper errmsg
9435 my $qasked = quotemeta($asked); # for searching
9436 # XXX: finds CR but not <CR>
9440 (?:[IB]<) # Optional markup
9441 $qasked # The command name
9448 ( # The command help:
9450 (?:[IB]<) # Optional markup
9451 $qasked # The command name
9452 ([\s\S]*?) # Lines starting with tabs
9456 ) # Line not starting with space
9457 # (Next command's help)
9461 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
9465 print_help("B<$asked> is not a debugger command.\n");
9467 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
9468 } ## end sub cmd_pre580_h
9470 =head2 Old C<W> command
9472 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
9480 # Delete all watch expressions.
9481 if ( $cmd =~ /^$/ ) {
9483 # No watching is going on.
9486 # Kill all the watch expressions and values.
9487 @to_watch = @old_watch = ();
9490 # Add a watch expression.
9491 elsif ( $cmd =~ /^(.*)/s ) {
9493 # add it to the list to be watched.
9496 # Get the current value of the expression.
9497 # Doesn't handle expressions returning list values!
9500 $val = ( defined $val ) ? "'$val'" : 'undef';
9503 push @old_watch, $val;
9505 # We're watching stuff.
9508 } ## end elsif ($cmd =~ /^(.*)/s)
9509 } ## end sub cmd_pre580_W
9511 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
9513 The debugger used to have a bunch of nearly-identical code to handle
9514 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
9515 C<cmd_prepost> unify all this into one set of code to handle the
9516 appropriate actions.
9518 =head2 C<cmd_pre590_prepost>
9520 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
9521 do something destructive. In pre 5.8 debuggers, the default action was to
9522 delete all the actions.
9526 sub cmd_pre590_prepost {
9528 my $line = shift || '*';
9531 return &cmd_prepost( $cmd, $line, $dbline );
9532 } ## end sub cmd_pre590_prepost
9534 =head2 C<cmd_prepost>
9536 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
9537 Since the lists of actions are all held in arrays that are pointed to by
9538 references anyway, all we have to do is pick the right array reference and
9539 then use generic code to all, delete, or list actions.
9546 # No action supplied defaults to 'list'.
9547 my $line = shift || '?';
9549 # Figure out what to put in the prompt.
9552 # Make sure we have some array or another to address later.
9553 # This means that if ssome reason the tests fail, we won't be
9554 # trying to stash actions or delete them from the wrong place.
9557 # < - Perl code to run before prompt.
9558 if ( $cmd =~ /^\</o ) {
9559 $which = 'pre-perl';
9563 # > - Perl code to run after prompt.
9564 elsif ( $cmd =~ /^\>/o ) {
9565 $which = 'post-perl';
9569 # { - first check for properly-balanced braces.
9570 elsif ( $cmd =~ /^\{/o ) {
9571 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
9573 "$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n";
9576 # Properly balanced. Pre-prompt debugger actions.
9578 $which = 'pre-debugger';
9581 } ## end elsif ( $cmd =~ /^\{/o )
9583 # Did we find something that makes sense?
9585 print $OUT "Confused by command: $cmd\n";
9592 if ( $line =~ /^\s*\?\s*$/o ) {
9595 # Nothing there. Complain.
9596 print $OUT "No $which actions.\n";
9600 # List the actions in the selected list.
9601 print $OUT "$which commands:\n";
9602 foreach my $action (@$aref) {
9603 print $OUT "\t$cmd -- $action\n";
9606 } ## end if ( $line =~ /^\s*\?\s*$/o)
9608 # Might be a delete.
9610 if ( length($cmd) == 1 ) {
9611 if ( $line =~ /^\s*\*\s*$/o ) {
9613 # It's a delete. Get rid of the old actions in the
9616 print $OUT "All $cmd actions cleared.\n";
9620 # Replace all the actions. (This is a <, >, or {).
9621 @$aref = action($line);
9623 } ## end if ( length($cmd) == 1)
9624 elsif ( length($cmd) == 2 ) {
9626 # Add the action to the line. (This is a <<, >>, or {{).
9627 push @$aref, action($line);
9631 # <<<, >>>>, {{{{{{ ... something not a command.
9633 "Confused by strange length of $which command($cmd)...\n";
9635 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
9637 } ## end sub cmd_prepost
9641 Contains the C<at_exit> routine that the debugger uses to issue the
9642 C<Debugged program terminated ...> message after the program completes. See
9643 the C<END> block documentation for more details.
9650 "Debugged program terminated. Use 'q' to quit or 'R' to restart.";
9653 package DB; # Do not trace this 1; below!