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_04';
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 # These variables control the execution of 'dumpvar.pl'.
886 # used to control die() reporting in diesignal()
889 use vars qw($CarpLevel);
892 # without threads, $filename is not defined until DB::DB is called
893 foreach my $k (keys (%INC)) {
894 share(\$main::{'_<'.$filename}) if defined $filename;
897 # Command-line + PERLLIB:
898 # Save the contents of @INC before they are modified elsewhere.
901 # This was an attempt to clear out the previous values of various
902 # trapped errors. Apparently it didn't help. XXX More info needed!
903 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
905 # We set these variables to safe values. We don't want to blindly turn
906 # off warnings, because other packages may still want them.
907 $trace = $signal = $single = 0; # Uninitialized warning suppression
908 # (local $^W cannot help - other packages!).
910 # Default to not exiting when program finishes; print the return
911 # value when the 'r' command is used to return from a subroutine.
912 $inhibit_exit = $option{PrintRet} = 1;
914 use vars qw($trace_to_depth);
916 # Default to 1E9 so it won't be limited to a certain recursion depth.
917 $trace_to_depth = 1E9;
919 =head1 OPTION PROCESSING
921 The debugger's options are actually spread out over the debugger itself and
922 C<dumpvar.pl>; some of these are variables to be set, while others are
923 subs to be called with a value. To try to make this a little easier to
924 manage, the debugger uses a few data structures to define what options
925 are legal and how they are to be processed.
927 First, the C<@options> array defines the I<names> of all the options that
933 CommandSet HistFile HistSize
934 hashDepth arrayDepth dumpDepth
935 DumpDBFiles DumpPackages DumpReused
936 compactDump veryCompact quote
937 HighBit undefPrint globPrint
938 PrintRet UsageOnly frame
940 ReadLine NonStop LineInfo
941 maxTraceLen recallCommand ShellBang
942 pager tkRunning ornaments
943 signalLevel warnLevel dieLevel
944 inhibit_exit ImmediateStop bareStringify
945 CreateTTY RemotePort windowSize
949 @RememberOnROptions = qw(DollarCaretP);
953 Second, C<optionVars> lists the variables that each option uses to save its
958 use vars qw(%optionVars);
961 hashDepth => \$dumpvar::hashDepth,
962 arrayDepth => \$dumpvar::arrayDepth,
963 CommandSet => \$CommandSet,
964 DumpDBFiles => \$dumpvar::dumpDBFiles,
965 DumpPackages => \$dumpvar::dumpPackages,
966 DumpReused => \$dumpvar::dumpReused,
967 HighBit => \$dumpvar::quoteHighBit,
968 undefPrint => \$dumpvar::printUndef,
969 globPrint => \$dumpvar::globPrint,
970 UsageOnly => \$dumpvar::usageOnly,
971 CreateTTY => \$CreateTTY,
972 bareStringify => \$dumpvar::bareStringify,
974 AutoTrace => \$trace,
975 inhibit_exit => \$inhibit_exit,
976 maxTraceLen => \$maxtrace,
977 ImmediateStop => \$ImmediateStop,
978 RemotePort => \$remoteport,
979 windowSize => \$window,
980 HistFile => \$histfile,
981 HistSize => \$histsize,
986 Third, C<%optionAction> defines the subroutine to be called to process each
991 use vars qw(%optionAction);
994 compactDump => \&dumpvar::compactDump,
995 veryCompact => \&dumpvar::veryCompact,
996 quote => \&dumpvar::quote,
999 ReadLine => \&ReadLine,
1000 NonStop => \&NonStop,
1001 LineInfo => \&LineInfo,
1002 recallCommand => \&recallCommand,
1003 ShellBang => \&shellBang,
1005 signalLevel => \&signalLevel,
1006 warnLevel => \&warnLevel,
1007 dieLevel => \&dieLevel,
1008 tkRunning => \&tkRunning,
1009 ornaments => \&ornaments,
1010 RemotePort => \&RemotePort,
1011 DollarCaretP => \&DollarCaretP,
1016 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1021 # Note that this list is not complete: several options not listed here
1022 # actually require that dumpvar.pl be loaded for them to work, but are
1023 # not in the table. A subsequent patch will correct this problem; for
1024 # the moment, we're just recommenting, and we are NOT going to change
1026 use vars qw(%optionRequire);
1029 compactDump => 'dumpvar.pl',
1030 veryCompact => 'dumpvar.pl',
1031 quote => 'dumpvar.pl',
1036 There are a number of initialization-related variables which can be set
1037 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1038 variable. These are:
1042 =item C<$rl> - readline control XXX needs more explanation
1044 =item C<$warnLevel> - whether or not debugger takes over warning handling
1046 =item C<$dieLevel> - whether or not debugger takes over die handling
1048 =item C<$signalLevel> - whether or not debugger takes over signal handling
1050 =item C<$pre> - preprompt actions (array reference)
1052 =item C<$post> - postprompt actions (array reference)
1056 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1058 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1064 # These guys may be defined in $ENV{PERL5DB} :
1065 $rl = 1 unless defined $rl;
1066 $warnLevel = 1 unless defined $warnLevel;
1067 $dieLevel = 1 unless defined $dieLevel;
1068 $signalLevel = 1 unless defined $signalLevel;
1069 $pre = [] unless defined $pre;
1070 $post = [] unless defined $post;
1071 $pretype = [] unless defined $pretype;
1072 $CreateTTY = 3 unless defined $CreateTTY;
1073 $CommandSet = '580' unless defined $CommandSet;
1078 share($signalLevel);
1088 The default C<die>, C<warn>, and C<signal> handlers are set up.
1092 warnLevel($warnLevel);
1093 dieLevel($dieLevel);
1094 signalLevel($signalLevel);
1098 The pager to be used is needed next. We try to get it from the
1099 environment first. If it's not defined there, we try to find it in
1100 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1101 then call the C<pager()> function to save the pager name.
1105 # This routine makes sure $pager is set up so that '|' can use it.
1108 # If PAGER is defined in the environment, use it.
1112 # If not, see if Config.pm defines it.
1113 : eval { require Config }
1114 && defined $Config::Config{pager}
1115 ? $Config::Config{pager}
1117 # If not, fall back to 'more'.
1120 unless defined $pager;
1124 We set up the command to be used to access the man pages, the command
1125 recall character (C<!> unless otherwise defined) and the shell escape
1126 character (C<!> unless otherwise defined). Yes, these do conflict, and
1127 neither works in the debugger at the moment.
1133 # Set up defaults for command recall and shell escape (note:
1134 # these currently don't work in linemode debugging).
1135 recallCommand("!") unless defined $prc;
1136 shellBang("!") unless defined $psh;
1140 We then set up the gigantic string containing the debugger help.
1141 We also set the limit on the number of arguments we'll display during a
1148 # If we didn't get a default for the length of eval/stack trace args,
1150 $maxtrace = 400 unless defined $maxtrace;
1152 =head2 SETTING UP THE DEBUGGER GREETING
1154 The debugger I<greeting> helps to inform the user how many debuggers are
1155 running, and whether the current debugger is the primary or a child.
1157 If we are the primary, we just hang onto our pid so we'll have it when
1158 or if we start a child debugger. If we are a child, we'll set things up
1159 so we'll have a unique greeting and so the parent will give us our own
1162 We save the current contents of the C<PERLDB_PIDS> environment variable
1163 because we mess around with it. We'll also need to hang onto it because
1164 we'll need it if we restart.
1166 Child debuggers make a label out of the current PID structure recorded in
1167 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1168 yet so the parent will give them one later via C<resetterm()>.
1172 # Save the current contents of the environment; we're about to
1173 # much with it. We'll need this if we have to restart.
1174 use vars qw($ini_pids);
1175 $ini_pids = $ENV{PERLDB_PIDS};
1177 use vars qw ($pids $term_pid);
1179 if ( defined $ENV{PERLDB_PIDS} ) {
1181 # We're a child. Make us a label out of the current PID structure
1182 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1183 # a term yet so the parent will give us one later via resetterm().
1185 my $env_pids = $ENV{PERLDB_PIDS};
1186 $pids = "[$env_pids]";
1188 # Unless we are on OpenVMS, all programs under the DCL shell run under
1191 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1195 $ENV{PERLDB_PIDS} .= "->$$";
1199 } ## end if (defined $ENV{PERLDB_PIDS...
1202 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1203 # child debugger, and mark us as the parent, so we'll know to set up
1204 # more TTY's is we have to.
1205 $ENV{PERLDB_PIDS} = "$$";
1210 use vars qw($pidprompt);
1213 # Sets up $emacs as a synonym for $slave_editor.
1214 use vars qw($slave_editor);
1215 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1217 =head2 READING THE RC FILE
1219 The debugger will read a file of initialization options if supplied. If
1220 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1224 # As noted, this test really doesn't check accurately that the debugger
1225 # is running at a terminal or not.
1227 use vars qw($rcfile);
1229 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1230 # this is the wrong metric!
1231 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
1236 The debugger does a safety test of the file to be read. It must be owned
1237 either by the current user or root, and must only be writable by the owner.
1241 # This wraps a safety test around "do" to read and evaluate the init file.
1243 # This isn't really safe, because there's a race
1244 # between checking and opening. The solution is to
1245 # open and fstat the handle, but then you have to read and
1246 # eval the contents. But then the silly thing gets
1247 # your lexical scope, which is unfortunate at best.
1251 # Just exactly what part of the word "CORE::" don't you understand?
1252 local $SIG{__WARN__};
1253 local $SIG{__DIE__};
1255 unless ( is_safe_file($file) ) {
1256 CORE::warn <<EO_GRIPE;
1257 perldb: Must not source insecure rcfile $file.
1258 You or the superuser must be the owner, and it must not
1259 be writable by anyone but its owner.
1262 } ## end unless (is_safe_file($file...
1265 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1266 } ## end sub safe_do
1268 # This is the safety test itself.
1270 # Verifies that owner is either real user or superuser and that no
1271 # one but owner may write to it. This function is of limited use
1272 # when called on a path instead of upon a handle, because there are
1273 # no guarantees that filename (by dirent) whose file (by ino) is
1274 # eventually accessed is the same as the one tested.
1275 # Assumes that the file's existence is not in doubt.
1278 stat($path) || return; # mysteriously vaporized
1279 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1281 return 0 if $uid != 0 && $uid != $<;
1282 return 0 if $mode & 022;
1284 } ## end sub is_safe_file
1286 # If the rcfile (whichever one we decided was the right one to read)
1287 # exists, we safely do it.
1289 safe_do("./$rcfile");
1292 # If there isn't one here, try the user's home directory.
1293 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1294 safe_do("$ENV{HOME}/$rcfile");
1297 # Else try the login directory.
1298 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1299 safe_do("$ENV{LOGDIR}/$rcfile");
1302 # If the PERLDB_OPTS variable has options in it, parse those out next.
1303 if ( defined $ENV{PERLDB_OPTS} ) {
1304 parse_options( $ENV{PERLDB_OPTS} );
1309 The last thing we do during initialization is determine which subroutine is
1310 to be used to obtain a new terminal when a new debugger is started. Right now,
1311 the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
1316 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1317 # Works if you're running an xterm or xterm-like window, or you're on
1318 # OS/2, or on Mac OS X. This may need some expansion.
1320 if (not defined &get_fork_TTY) # only if no routine exists
1322 if ( defined $remoteport ) {
1323 # Expect an inetd-like server
1324 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1326 elsif (defined $ENV{TERM} # If we know what kind
1327 # of terminal this is,
1328 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1329 and defined $ENV{DISPLAY} # and what display it's on,
1332 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1334 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1335 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1337 elsif ( $^O eq 'darwin' # If this is Mac OS X
1338 and defined $ENV{TERM_PROGRAM} # and we're running inside
1339 and $ENV{TERM_PROGRAM}
1340 eq 'Apple_Terminal' # Terminal.app
1343 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1345 } ## end if (not defined &get_fork_TTY...
1347 # untaint $^O, which may have been tainted by the last statement.
1348 # see bug [perl #24674]
1352 # Here begin the unreadable code. It needs fixing.
1354 =head2 RESTART PROCESSING
1356 This section handles the restart command. When the C<R> command is invoked, it
1357 tries to capture all of the state it can into environment variables, and
1358 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1359 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1360 the R command stuffed into the environment variables.
1362 PERLDB_RESTART - flag only, contains no restart data itself.
1363 PERLDB_HIST - command history, if it's available
1364 PERLDB_ON_LOAD - breakpoints set by the rc file
1365 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1366 PERLDB_VISITED - files that had breakpoints
1367 PERLDB_FILE_... - breakpoints for a file
1368 PERLDB_OPT - active options
1369 PERLDB_INC - the original @INC
1370 PERLDB_PRETYPE - preprompt debugger actions
1371 PERLDB_PRE - preprompt Perl code
1372 PERLDB_POST - post-prompt Perl code
1373 PERLDB_TYPEAHEAD - typeahead captured by readline()
1375 We chug through all these variables and plug the values saved in them
1376 back into the appropriate spots in the debugger.
1380 use vars qw(@hist @truehist %postponed_file @typeahead);
1382 if ( exists $ENV{PERLDB_RESTART} ) {
1384 # We're restarting, so we don't need the flag that says to restart anymore.
1385 delete $ENV{PERLDB_RESTART};
1388 @hist = get_list('PERLDB_HIST');
1389 %break_on_load = get_list("PERLDB_ON_LOAD");
1390 %postponed = get_list("PERLDB_POSTPONE");
1394 share(%break_on_load);
1397 # restore breakpoints/actions
1398 my @had_breakpoints = get_list("PERLDB_VISITED");
1399 for my $file_idx ( 0 .. $#had_breakpoints ) {
1400 my $filename = $had_breakpoints[$file_idx];
1401 my %pf = get_list("PERLDB_FILE_$file_idx");
1402 $postponed_file{ $filename } = \%pf if %pf;
1403 my @lines = sort {$a <=> $b} keys(%pf);
1404 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1405 for my $line_idx (0 .. $#lines) {
1406 _set_breakpoint_enabled_status(
1409 ($enabled_statuses[$line_idx] ? 1 : ''),
1415 my %opt = get_list("PERLDB_OPT");
1417 while ( ( $opt, $val ) = each %opt ) {
1418 $val =~ s/[\\\']/\\$1/g;
1419 parse_options("$opt'$val'");
1422 # restore original @INC
1423 @INC = get_list("PERLDB_INC");
1426 # return pre/postprompt actions and typeahead buffer
1427 $pretype = [ get_list("PERLDB_PRETYPE") ];
1428 $pre = [ get_list("PERLDB_PRE") ];
1429 $post = [ get_list("PERLDB_POST") ];
1430 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1431 } ## end if (exists $ENV{PERLDB_RESTART...
1433 =head2 SETTING UP THE TERMINAL
1435 Now, we'll decide how the debugger is going to interact with the user.
1436 If there's no TTY, we set the debugger to run non-stop; there's not going
1437 to be anyone there to enter commands.
1441 use vars qw($notty $runnonstop $console $tty $LINEINFO);
1442 use vars qw($lineinfo $doccmd);
1451 If there is a TTY, we have to determine who it belongs to before we can
1452 proceed. If this is a slave editor or graphical debugger (denoted by
1453 the first command-line switch being '-emacs'), we shift this off and
1454 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1460 # Is Perl being run from a slave editor or graphical debugger?
1461 # If so, don't use readline, and set $slave_editor = 1.
1463 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1464 $rl = 0, shift(@main::ARGV) if $slave_editor;
1466 #require Term::ReadLine;
1470 We then determine what the console should be on various systems:
1474 =item * Cygwin - We use C<stdin> instead of a separate device.
1478 if ( $^O eq 'cygwin' ) {
1480 # /dev/tty is binary. use stdin for textmode
1484 =item * Unix - use C</dev/tty>.
1488 elsif ( -e "/dev/tty" ) {
1489 $console = "/dev/tty";
1492 =item * Windows or MSDOS - use C<con>.
1496 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1500 =item * VMS - use C<sys$command>.
1506 # everything else is ...
1507 $console = "sys\$command";
1514 Several other systems don't use a specific console. We C<undef $console>
1515 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1516 with a slave editor, Epoc).
1520 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1522 # /dev/tty is binary. use stdin for textmode
1526 if ( $^O eq 'NetWare' ) {
1528 # /dev/tty is binary. use stdin for textmode
1532 # In OS/2, we need to use STDIN to get textmode too, even though
1533 # it pretty much looks like Unix otherwise.
1534 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1539 # EPOC also falls into the 'got to use STDIN' camp.
1540 if ( $^O eq 'epoc' ) {
1546 If there is a TTY hanging around from a parent, we use that as the console.
1550 $console = $tty if defined $tty;
1552 =head2 SOCKET HANDLING
1554 The debugger is capable of opening a socket and carrying out a debugging
1555 session over the socket.
1557 If C<RemotePort> was defined in the options, the debugger assumes that it
1558 should try to start a debugging session on that port. It builds the socket
1559 and then tries to connect the input and output filehandles to it.
1563 # Handle socket stuff.
1565 if ( defined $remoteport ) {
1567 # If RemotePort was defined in the options, connect input and output
1569 $IN = $OUT = connect_remoteport();
1570 } ## end if (defined $remoteport)
1574 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1575 this is probably a situation where multiple debuggers are running (for example,
1576 a backticked command that starts up another debugger). We create a new IN and
1577 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1585 # Two debuggers running (probably a system or a backtick that invokes
1586 # the debugger itself under the running one). create a new IN and OUT
1587 # filehandle, and do the necessary mojo to create a new tty if we
1588 # know how, and we can.
1589 create_IN_OUT(4) if $CreateTTY & 4;
1592 # If we have a console, check to see if there are separate ins and
1593 # outs to open. (They are assumed identical if not.)
1595 my ( $i, $o ) = split /,/, $console;
1596 $o = $i unless defined $o;
1598 # read/write on in, or just read, or read on STDIN.
1600 || open( IN, "<$i" )
1601 || open( IN, "<&STDIN" );
1603 # read/write/create/clobber out, or write/create/clobber out,
1604 # or merge with STDERR, or merge with STDOUT.
1606 || open( OUT, ">$o" )
1607 || open( OUT, ">&STDERR" )
1608 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1610 } ## end if ($console)
1611 elsif ( not defined $console ) {
1613 # No console. Open STDIN.
1614 open( IN, "<&STDIN" );
1616 # merge with STDERR, or with STDOUT.
1617 open( OUT, ">&STDERR" )
1618 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1619 $console = 'STDIN/OUT';
1620 } ## end elsif (not defined $console)
1622 # Keep copies of the filehandles so that when the pager runs, it
1623 # can close standard input without clobbering ours.
1624 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1625 } ## end elsif (from if(defined $remoteport))
1627 # Unbuffer DB::OUT. We need to see responses right away.
1630 # Line info goes to debugger output unless pointed elsewhere.
1631 # Pointing elsewhere makes it possible for slave editors to
1632 # keep track of file and position. We have both a filehandle
1633 # and a I/O description to keep track of.
1634 $LINEINFO = $OUT unless defined $LINEINFO;
1635 $lineinfo = $console unless defined $lineinfo;
1636 # share($LINEINFO); # <- unable to share globs
1641 To finish initialization, we show the debugger greeting,
1642 and then call the C<afterinit()> subroutine if there is one.
1646 # Show the debugger greeting.
1647 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1648 unless ($runnonstop) {
1651 if ( $term_pid eq '-1' ) {
1652 print $OUT "\nDaughter DB session started...\n";
1655 print $OUT "\nLoading DB routines from $header\n";
1658 $slave_editor ? "enabled" : "available", ".\n"
1661 "\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
1662 } ## end else [ if ($term_pid eq '-1')
1663 } ## end unless ($runnonstop)
1664 } ## end else [ if ($notty)
1666 # XXX This looks like a bug to me.
1667 # Why copy to @ARGS and then futz with @args?
1670 # Make sure backslashes before single quotes are stripped out, and
1671 # keep args unless they are numeric (XXX why?)
1672 # s/\'/\\\'/g; # removed while not justified understandably
1673 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1676 # If there was an afterinit() sub defined, call it. It will get
1677 # executed in our scope, so it can fiddle with debugger globals.
1678 if ( defined &afterinit ) { # May be defined in $rcfile
1682 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1683 use vars qw($I_m_init);
1687 ############################################################ Subroutines
1693 This gigantic subroutine is the heart of the debugger. Called before every
1694 statement, its job is to determine if a breakpoint has been reached, and
1695 stop if so; read commands from the user, parse them, and execute
1696 them, and then send execution off to the next statement.
1698 Note that the order in which the commands are processed is very important;
1699 some commands earlier in the loop will actually alter the C<$cmd> variable
1700 to create other commands to be executed later. This is all highly I<optimized>
1701 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1702 see what's happening in any given command.
1733 # lock the debugger and get the thread id for the prompt
1737 my ($prefix, $after, $infix);
1740 if ($ENV{PERL5DB_THREADED}) {
1741 $tid = eval { "[".threads->tid."]" };
1744 # Check for whether we should be running continuously or not.
1745 # _After_ the perl program is compiled, $single is set to 1:
1746 if ( $single and not $second_time++ ) {
1748 # Options say run non-stop. Run until we get an interrupt.
1749 if ($runnonstop) { # Disable until signal
1750 # If there's any call stack in place, turn off single
1751 # stepping into subs throughout the stack.
1752 for my $i (0 .. $stack_depth) {
1756 # And we are now no longer in single-step mode.
1759 # If we simply returned at this point, we wouldn't get
1760 # the trace info. Fall on through.
1762 } ## end if ($runnonstop)
1764 elsif ($ImmediateStop) {
1766 # We are supposed to stop here; XXX probably a break.
1767 $ImmediateStop = 0; # We've processed it; turn it off
1768 $signal = 1; # Simulate an interrupt to force
1769 # us into the command loop
1771 } ## end if ($single and not $second_time...
1773 # If we're in single-step mode, or an interrupt (real or fake)
1774 # has occurred, turn off non-stop mode.
1775 $runnonstop = 0 if $single or $signal;
1777 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1778 # The code being debugged may have altered them.
1781 # Since DB::DB gets called after every line, we can use caller() to
1782 # figure out where we last were executing. Sneaky, eh? This works because
1783 # caller is returning all the extra information when called from the
1785 local ( $package, $filename, $line ) = caller;
1786 $filename_ini = $filename;
1788 # set up the context for DB::eval, so it can properly execute
1789 # code on behalf of the user. We add the package in so that the
1790 # code is eval'ed in the proper package (not in the debugger!).
1791 local $usercontext = _calc_usercontext($package);
1793 # Create an alias to the active file magical array to simplify
1795 local (*dbline) = $main::{ '_<' . $filename };
1797 # Last line in the program.
1800 # if we have something here, see if we should break.
1802 # $stop is lexical and local to this block - $action on the other hand
1807 && _is_breakpoint_enabled($filename, $line)
1808 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1811 # Stop if the stop criterion says to just stop.
1812 if ( $stop eq '1' ) {
1816 # It's a conditional stop; eval it in the user's context and
1817 # see if we should stop. If so, remove the one-time sigil.
1819 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1821 # If the breakpoint is temporary, then delete its enabled status.
1822 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1823 _cancel_breakpoint_temp_enabled_status($filename, $line);
1826 } ## end if ($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 .. $#to_watch) {
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 $n (0 ..
1857 } ## end if ($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 if ($cmd =~ s/\\\z/\n/) {
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<$?>.
2231 =head4 C<t> - trace [n]
2233 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2234 If level is specified, set C<$trace_to_depth>.
2238 if (my ($levels) = $cmd =~ /\At(?:\s+(\d+))?\z/) {
2241 $trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
2242 print $OUT "Trace = "
2244 ? ( $levels ? "on (to level $trace_to_depth)" : "on" )
2249 =head4 C<S> - list subroutines matching/not matching a pattern
2251 Walks through C<%sub>, checking to see whether or not to print the name.
2255 if (my ($print_all_subs, $should_reverse, $Spatt)
2256 = $cmd =~ /\AS(\s+(!)?(.+))?\z/) {
2257 # $Spatt is the pattern (if any) to use.
2259 my $Srev = defined $should_reverse;
2260 # No args - print all subs.
2261 my $Snocheck = !defined $print_all_subs;
2263 # Need to make these sane here.
2267 # Search through the debugger's magical hash of subs.
2268 # If $nocheck is true, just print the sub name.
2269 # Otherwise, check it against the pattern. We then use
2270 # the XOR trick to reverse the condition as required.
2271 foreach $subname ( sort( keys %sub ) ) {
2272 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2273 print $OUT $subname, "\n";
2279 =head4 C<X> - list variables in current package
2281 Since the C<V> command actually processes this, just change this to the
2282 appropriate C<V> command and fall through.
2286 $cmd =~ s/^X\b/V $package/;
2288 =head4 C<V> - list variables
2290 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2294 # Bare V commands get the currently-being-debugged package
2297 $cmd = "V $package";
2300 # V - show variables in package.
2301 if (my ($new_packname, $new_vars_str) =
2302 $cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
2304 # Save the currently selected filehandle and
2305 # force output to debugger's filehandle (dumpvar
2306 # just does "print" for output).
2307 my $savout = select($OUT);
2309 # Grab package name and variables to dump.
2310 $packname = $new_packname;
2311 my @vars = split( ' ', $new_vars_str );
2313 # If main::dumpvar isn't here, get it.
2314 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
2315 if ( defined &main::dumpvar ) {
2317 # We got it. Turn off subroutine entry/exit messages
2318 # for the moment, along with return values.
2322 # must detect sigpipe failures - not catching
2323 # then will cause the debugger to die.
2327 defined $option{dumpDepth}
2328 ? $option{dumpDepth}
2329 : -1, # assume -1 unless specified
2334 # The die doesn't need to include the $@, because
2335 # it will automatically get propagated for us.
2337 die unless $@ =~ /dumpvar print failed/;
2339 } ## end if (defined &main::dumpvar)
2342 # Couldn't load dumpvar.
2343 print $OUT "dumpvar.pl not available.\n";
2346 # Restore the output filehandle, and go round again.
2351 =head4 C<x> - evaluate and print an expression
2353 Hands the expression off to C<DB::eval>, setting it up to print the value
2354 via C<dumpvar.pl> instead of just printing it directly.
2358 if ($cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
2359 $onetimeDump = 'dump'; # main::dumpvar shows the output
2361 # handle special "x 3 blah" syntax XXX propagate
2362 # doc back to special variables.
2363 if ( $cmd =~ s#\A\s*(\d+)(?=\s)# #) {
2364 $onetimedumpDepth = $1;
2368 =head4 C<m> - print methods
2370 Just uses C<DB::methods> to determine what methods are available.
2374 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2379 # m expr - set up DB::eval to do the work
2380 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2381 $onetimeDump = 'methods'; # method output gets used there
2384 =head4 C<f> - switch files
2388 if (($file) = $cmd =~ /\Af\b\s*(.*)/) {
2391 # help for no arguments (old-style was return from sub).
2394 "The old f command is now the r command.\n"; # hint
2395 print $OUT "The new f command switches filenames.\n";
2397 } ## end if (!$file)
2399 # if not in magic file list, try a close match.
2400 if ( !defined $main::{ '_<' . $file } ) {
2401 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2403 $try = substr( $try, 2 );
2404 print $OUT "Choosing $try matching '$file':\n";
2407 } ## end if (($try) = grep(m#^_<.*$file#...
2408 } ## end if (!defined $main::{ ...
2410 # If not successfully switched now, we failed.
2411 if ( !defined $main::{ '_<' . $file } ) {
2412 print $OUT "No file matching '$file' is loaded.\n";
2416 # We switched, so switch the debugger internals around.
2417 elsif ( $file ne $filename ) {
2418 *dbline = $main::{ '_<' . $file };
2423 } ## end elsif ($file ne $filename)
2425 # We didn't switch; say we didn't.
2427 print $OUT "Already in $file.\n";
2432 =head4 C<.> - return to last-executed line.
2434 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2435 and then we look up the line in the magical C<%dbline> hash.
2441 $incr = -1; # stay at current line
2443 # Reset everything to the old location.
2445 $filename = $filename_ini;
2446 *dbline = $main::{ '_<' . $filename };
2450 print_lineinfo($position);
2454 =head4 C<-> - back one window
2456 We change C<$start> to be one window back; if we go back past the first line,
2457 we set it to be the first line. We ser C<$incr> to put us back at the
2458 currently-executing line, and then put a C<l $start +> (list one window from
2459 C<$start>) in C<$cmd> to be executed later.
2463 # - - back a window.
2466 # back up by a window; go to 1 if back too far.
2467 $start -= $incr + $window + 1;
2468 $start = 1 if $start <= 0;
2469 $incr = $window - 1;
2471 # Generate and execute a "l +" command (handled below).
2472 $cmd = 'l ' . ($start) . '+';
2475 =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>, {, {{>
2477 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2478 problems, most notably that the default case of several commands destroying
2479 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2480 retain the old commands for those who were used to using them or who preferred
2481 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2482 deal with them instead of processing them in-line.
2486 # All of these commands were remapped in perl 5.8.0;
2487 # we send them off to the secondary dispatcher (see below).
2488 if (my ($cmd_letter, $my_arg) = $cmd =~ /\A([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so) {
2489 &cmd_wrapper( $cmd_letter, $my_arg, $line );
2493 =head4 C<y> - List lexicals in higher scope
2495 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2496 above the current one and then displays then using C<dumpvar.pl>.
2500 if (my ($match_level, $match_vars)
2501 = $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/) {
2503 # See if we've got the necessary support.
2504 eval { require PadWalker; PadWalker->VERSION(0.08) }
2507 ? "PadWalker module not found - please install\n"
2512 # Load up dumpvar if we don't have it. If we can, that is.
2513 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
2514 defined &main::dumpvar
2515 or print $OUT "dumpvar.pl not available.\n"
2518 # Got all the modules we need. Find them and print them.
2519 my @vars = split( ' ', $match_vars || '' );
2522 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
2524 # Oops. Can't find it.
2525 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2527 # Show the desired vars with dumplex().
2528 my $savout = select($OUT);
2530 # Have dumplex dump the lexicals.
2531 dumpvar::dumplex( $_, $h->{$_},
2532 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
2539 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2541 All of the commands below this point don't work after the program being
2542 debugged has ended. All of them check to see if the program has ended; this
2543 allows the commands to be relocated without worrying about a 'line of
2544 demarcation' above which commands can be entered anytime, and below which
2547 =head4 C<n> - single step, but don't trace down into subs
2549 Done by setting C<$single> to 2, which forces subs to execute straight through
2550 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2551 so a null command knows what to re-execute.
2557 end_report(), next CMD if $finished and $level <= 1;
2559 # Single step, but don't enter subs.
2562 # Save for empty command (repeat last).
2567 =head4 C<s> - single-step, entering subs
2569 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2570 subs. Also saves C<s> as C<$lastcmd>.
2577 # Get out and restart the command loop if program
2579 end_report(), next CMD if $finished and $level <= 1;
2581 # Single step should enter subs.
2584 # Save for empty command (repeat last).
2589 =head4 C<c> - run continuously, setting an optional breakpoint
2591 Most of the code for this command is taken up with locating the optional
2592 breakpoint, which is either a subroutine name or a line number. We set
2593 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2594 in this and all call levels above this one.
2598 # c - start continuous execution.
2599 if (($i) = $cmd =~ m#\Ac\b\s*([\w:]*)\s*\z#) {
2601 # Hey, show's over. The debugged program finished
2602 # executing already.
2603 end_report(), next CMD if $finished and $level <= 1;
2605 # Capture the place to put a one-time break.
2608 # Probably not needed, since we finish an interactive
2609 # sub-session anyway...
2610 # local $filename = $filename;
2611 # local *dbline = *dbline; # XXX Would this work?!
2613 # The above question wonders if localizing the alias
2614 # to the magic array works or not. Since it's commented
2615 # out, we'll just leave that to speculation for now.
2617 # If the "subname" isn't all digits, we'll assume it
2618 # is a subroutine name, and try to find it.
2619 if ( $subname =~ /\D/ ) { # subroutine name
2620 # Qualify it to the current package unless it's
2621 # already qualified.
2622 $subname = $package . "::" . $subname
2623 unless $subname =~ /::/;
2625 # find_sub will return "file:line_number" corresponding
2626 # to where the subroutine is defined; we call find_sub,
2627 # break up the return value, and assign it in one
2629 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2631 # Force the line number to be numeric.
2634 # If we got a line number, we found the sub.
2637 # Switch all the debugger's internals around so
2638 # we're actually working with that file.
2640 *dbline = $main::{ '_<' . $filename };
2642 # Mark that there's a breakpoint in this file.
2643 $had_breakpoints{$filename} |= 1;
2645 # Scan forward to the first executable line
2646 # after the 'sub whatever' line.
2648 ++$i while $dbline[$i] == 0 && $i < $max;
2651 # We didn't find a sub by that name.
2653 print $OUT "Subroutine $subname not found.\n";
2656 } ## end if ($subname =~ /\D/)
2658 # At this point, either the subname was all digits (an
2659 # absolute line-break request) or we've scanned through
2660 # the code following the definition of the sub, looking
2661 # for an executable, which we may or may not have found.
2663 # If $i (which we set $subname from) is non-zero, we
2664 # got a request to break at some line somewhere. On
2665 # one hand, if there wasn't any real subroutine name
2666 # involved, this will be a request to break in the current
2667 # file at the specified line, so we have to check to make
2668 # sure that the line specified really is breakable.
2670 # On the other hand, if there was a subname supplied, the
2671 # preceding block has moved us to the proper file and
2672 # location within that file, and then scanned forward
2673 # looking for the next executable line. We have to make
2674 # sure that one was found.
2676 # On the gripping hand, we can't do anything unless the
2677 # current value of $i points to a valid breakable line.
2682 if ( $dbline[$i] == 0 ) {
2683 print $OUT "Line $i not breakable.\n";
2687 # Yes. Set up the one-time-break sigil.
2688 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2689 _enable_breakpoint_temp_enabled_status($filename, $i);
2692 # Turn off stack tracing from here up.
2693 for my $i (0 .. $stack_depth) {
2699 =head4 C<r> - return from a subroutine
2701 For C<r> to work properly, the debugger has to stop execution again
2702 immediately after the return is executed. This is done by forcing
2703 single-stepping to be on in the call level above the current one. If
2704 we are printing return values when a C<r> is executed, set C<$doret>
2705 appropriately, and force us out of the command loop.
2709 # r - return from the current subroutine.
2712 # Can't do anything if the program's over.
2713 end_report(), next CMD if $finished and $level <= 1;
2715 # Turn on stack trace.
2716 $stack[$stack_depth] |= 1;
2718 # Print return value unless the stack is empty.
2719 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2723 =head4 C<T> - stack trace
2725 Just calls C<DB::print_trace>.
2730 print_trace( $OUT, 1 ); # skip DB
2734 =head4 C<w> - List window around current line.
2736 Just calls C<DB::cmd_w>.
2740 if (my ($arg) = $cmd =~ /\Aw\b\s*(.*)/s) {
2741 &cmd_w( 'w', $arg );
2745 =head4 C<W> - watch-expression processing.
2747 Just calls C<DB::cmd_W>.
2751 if (my ($arg) = $cmd =~ /\AW\b\s*(.*)/s) {
2752 &cmd_W( 'W', $arg );
2756 =head4 C</> - search forward for a string in the source
2758 We take the argument and treat it as a pattern. If it turns out to be a
2759 bad one, we return the error we got from trying to C<eval> it and exit.
2760 If not, we create some code to do the search and C<eval> it so it can't
2765 # The pattern as a string.
2766 use vars qw($inpat);
2768 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2770 # Remove the final slash.
2771 $inpat =~ s:([^\\])/$:$1:;
2773 # If the pattern isn't null ...
2774 if ( $inpat ne "" ) {
2776 # Turn of warn and die procesing for a bit.
2777 local $SIG{__DIE__};
2778 local $SIG{__WARN__};
2780 # Create the pattern.
2781 eval '$inpat =~ m' . "\a$inpat\a";
2784 # Oops. Bad pattern. No biscuit.
2785 # Print the eval error and go back for more
2791 } ## end if ($inpat ne "")
2793 # Set up to stop on wrap-around.
2796 # Don't move off the current line.
2799 # Done in eval so nothing breaks if the pattern
2800 # does something weird.
2803 # Move ahead one line.
2806 # Wrap if we pass the last line.
2807 $start = 1 if ($start > $max);
2809 # Stop if we have gotten back to this line again,
2810 last if ($start == $end);
2812 # A hit! (Note, though, that we are doing
2813 # case-insensitive matching. Maybe a qr//
2814 # expression would be better, so the user could
2815 # do case-sensitive matching if desired.
2816 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2817 if ($slave_editor) {
2818 # Handle proper escaping in the slave.
2819 print $OUT "\032\032$filename:$start:0\n";
2822 # Just print the line normally.
2823 print $OUT "$start:\t",$dbline[$start],"\n";
2825 # And quit since we found something.
2830 # If we wrapped, there never was a match.
2831 print $OUT "/$pat/: not found\n" if ( $start == $end );
2835 =head4 C<?> - search backward for a string in the source
2837 Same as for C</>, except the loop runs backwards.
2841 # ? - backward pattern search.
2842 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2844 # Get the pattern, remove trailing question mark.
2845 $inpat =~ s:([^\\])\?$:$1:;
2847 # If we've got one ...
2848 if ( $inpat ne "" ) {
2850 # Turn off die & warn handlers.
2851 local $SIG{__DIE__};
2852 local $SIG{__WARN__};
2853 eval '$inpat =~ m' . "\a$inpat\a";
2857 # Ouch. Not good. Print the error.
2862 } ## end if ($inpat ne "")
2864 # Where we are now is where to stop after wraparound.
2867 # Don't move away from this line.
2870 # Search inside the eval to prevent pattern badness
2877 # Wrap if we pass the first line.
2879 $start = $max if ($start <= 0);
2881 # Quit if we get back where we started,
2882 last if ($start == $end);
2885 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2886 if ($slave_editor) {
2887 # Yep, follow slave editor requirements.
2888 print $OUT "\032\032$filename:$start:0\n";
2891 # Yep, just print normally.
2892 print $OUT "$start:\t",$dbline[$start],"\n";
2900 # Say we failed if the loop never found anything,
2901 print $OUT "?$pat?: not found\n" if ( $start == $end );
2905 =head4 C<$rc> - Recall command
2907 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2908 that the terminal supports history). It find the the command required, puts it
2909 into C<$cmd>, and redoes the loop to execute it.
2913 # $rc - recall command.
2914 if (my ($minus, $arg) = $cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
2916 # No arguments, take one thing off history.
2917 pop(@hist) if length($cmd) > 1;
2919 # Relative (- found)?
2920 # Y - index back from most recent (by 1 if bare minus)
2921 # N - go to that particular command slot or the last
2922 # thing if nothing following.
2923 $i = $minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist );
2925 # Pick out the command desired.
2928 # Print the command to be executed and restart the loop
2929 # with that command in the buffer.
2930 print $OUT $cmd, "\n";
2934 =head4 C<$sh$sh> - C<system()> command
2936 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2937 C<STDOUT> from getting messed up.
2941 # $sh$sh - run a shell command (if it's all ASCII).
2942 # Can't run shell commands with Unicode in the debugger, hmm.
2943 if (my ($arg) = $cmd =~ m#\A$sh$sh\s*(.*)#ms) {
2950 =head4 C<$rc I<pattern> $rc> - Search command history
2952 Another command to manipulate C<@hist>: this one searches it with a pattern.
2953 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
2957 # $rc pattern $rc - find a command in the history.
2958 if (my ($arg) = $cmd =~ /\A$rc([^$rc].*)\z/) {
2960 # Create the pattern to use.
2963 # Toss off last entry if length is >1 (and it always is).
2964 pop(@hist) if length($cmd) > 1;
2966 # Look backward through the history.
2967 for ( $i = $#hist ; $i ; --$i ) {
2968 # Stop if we find it.
2969 last if $hist[$i] =~ /$pat/;
2975 print $OUT "No such command!\n\n";
2979 # Found it. Put it in the buffer, print it, and process it.
2981 print $OUT $cmd, "\n";
2985 =head4 C<$sh> - Invoke a shell
2987 Uses C<DB::system> to invoke a shell.
2991 # $sh - start a shell.
2992 if ($cmd =~ /\A$sh\z/) {
2994 # Run the user's shell. If none defined, run Bourne.
2995 # We resume execution when the shell terminates.
2996 &system( $ENV{SHELL} || "/bin/sh" );
3000 =head4 C<$sh I<command>> - Force execution of a command in a shell
3002 Like the above, but the command is passed to the shell. Again, we use
3003 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3007 # $sh command - start a shell and run a command in it.
3008 if (my ($arg) = $cmd =~ m#\A$sh\s*(.*)#ms) {
3010 # XXX: using csh or tcsh destroys sigint retvals!
3011 #&system($1); # use this instead
3013 # use the user's shell, or Bourne if none defined.
3014 &system( $ENV{SHELL} || "/bin/sh", "-c", $arg );
3018 =head4 C<H> - display commands in history
3020 Prints the contents of C<@hist> (if any).
3024 if ($cmd =~ /\AH\b\s*\*/) {
3025 @hist = @truehist = ();
3026 print $OUT "History cleansed\n";
3031 = $cmd =~ /\AH\b\s*(?:-(\d+))?/) {
3033 # Anything other than negative numbers is ignored by
3034 # the (incorrect) pattern, so this test does nothing.
3035 $end = $num ? ( $#hist - $num ) : 0;
3037 # Set to the minimum if less than zero.
3038 $hist = 0 if $hist < 0;
3040 # Start at the end of the array.
3041 # Stay in while we're still above the ending value.
3042 # Tick back by one each time around the loop.
3043 for ( $i = $#hist ; $i > $end ; $i-- ) {
3045 # Print the command unless it has no arguments.
3046 print $OUT "$i: ", $hist[$i], "\n"
3047 unless $hist[$i] =~ /^.?$/;
3052 =head4 C<man, doc, perldoc> - look up documentation
3054 Just calls C<runman()> to print the appropriate document.
3058 # man, perldoc, doc - show manual pages.
3060 = $cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
3067 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3068 the bottom of the loop.
3072 my $print_cmd = 'print {$DB::OUT} ';
3073 # p - print (no args): print $_.
3075 $cmd = $print_cmd . '$_';
3078 # p - print the given expression.
3079 $cmd =~ s/\Ap\b/$print_cmd /;
3081 =head4 C<=> - define command alias
3083 Manipulates C<%alias> to add or list command aliases.
3087 # = - set up a command alias.
3088 if ($cmd =~ s/\A=\s*//) {
3090 if ( length $cmd == 0 ) {
3092 # No args, get current aliases.
3093 @keys = sort keys %alias;
3095 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3097 # Creating a new alias. $k is alias name, $v is
3100 # can't use $_ or kill //g state
3101 for my $x ( $k, $v ) {
3103 # Escape "alarm" characters.
3107 # Substitute key for value, using alarm chars
3108 # as separators (which is why we escaped them in
3110 $alias{$k} = "s\a$k\a$v\a";
3112 # Turn off standard warn and die behavior.
3113 local $SIG{__DIE__};
3114 local $SIG{__WARN__};
3117 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3119 # Nope. Bad alias. Say so and get out.
3120 print $OUT "Can't alias $k to $v: $@\n";
3125 # We'll only list the new one.
3127 } ## end elsif (my ($k, $v) = ($cmd...
3129 # The argument is the alias to list.
3137 # Messy metaquoting: Trim the substitution code off.
3138 # We use control-G as the delimiter because it's not
3139 # likely to appear in the alias.
3140 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3143 print $OUT "$k\t= $1\n";
3145 elsif ( defined $alias{$k} ) {
3147 # Couldn't trim it off; just print the alias code.
3148 print $OUT "$k\t$alias{$k}\n";
3153 print "No alias for $k\n";
3155 } ## end for my $k (@keys)
3159 =head4 C<source> - read commands from a file.
3161 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3166 # source - read commands from a file (or pipe!) and execute.
3167 if (my ($sourced_fn) = $cmd =~ /\Asource\s+(.*\S)/) {
3168 if ( open my $fh, $sourced_fn ) {
3170 # Opened OK; stick it in the list of file handles.
3176 &warn("Can't execute '$sourced_fn': $!\n");
3181 if (my ($which_cmd, $position)
3182 = $cmd =~ /^(enable|disable)\s+(\S+)\s*$/) {
3184 my ($fn, $line_num);
3185 if ($position =~ m{\A\d+\z})
3188 $line_num = $position;
3190 elsif (my ($new_fn, $new_line_num)
3191 = $position =~ m{\A(.*):(\d+)\z}) {
3192 ($fn, $line_num) = ($new_fn, $new_line_num);
3196 &warn("Wrong spec for enable/disable argument.\n");
3200 if (_has_breakpoint_data_ref($fn, $line_num)) {
3201 _set_breakpoint_enabled_status($fn, $line_num,
3202 ($which_cmd eq 'enable' ? 1 : '')
3206 &warn("No breakpoint set at ${fn}:${line_num}\n");
3213 =head4 C<save> - send current history to a file
3215 Takes the complete history, (not the shrunken version you see with C<H>),
3216 and saves it to the given filename, so it can be replayed using C<source>.
3218 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3222 # save source - write commands to a file for later use
3223 if (my ($new_fn) = $cmd =~ /\Asave\s*(.*)\z/) {
3224 my $filename = $new_fn || '.perl5dbrc'; # default?
3225 if ( open my $fh, '>', $filename ) {
3227 # chomp to remove extraneous newlines from source'd files
3228 chomp( my @truelist =
3229 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3231 print $fh join( "\n", @truelist );
3232 print "commands saved in $file\n";
3235 &warn("Can't save debugger commands in '$new_fn': $!\n");
3240 =head4 C<R> - restart
3242 Restart the debugger session.
3244 =head4 C<rerun> - rerun the current session
3246 Return to any given position in the B<true>-history list
3250 # R - restart execution.
3251 # rerun - controlled restart execution.
3252 if (my ($cmd_cmd, $cmd_params) =
3253 $cmd =~ /\A((?:R)|(?:rerun\s*(.*)))\z/) {
3254 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
3256 # Close all non-system fds for a clean restart. A more
3257 # correct method would be to close all fds that were not
3258 # open when the process started, but this seems to be
3259 # hard. See "debugger 'R'estart and open database
3260 # connections" on p5p.
3262 my $max_fd = 1024; # default if POSIX can't be loaded
3263 if (eval { require POSIX }) {
3264 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
3267 if (defined $max_fd) {
3268 foreach ($^F+1 .. $max_fd-1) {
3269 next unless open FD_TO_CLOSE, "<&=$_";
3274 # And run Perl again. We use exec() to keep the
3275 # PID stable (and that way $ini_pids is still valid).
3276 exec(@args) || print $OUT "exec failed: $!\n";
3281 =head4 C<|, ||> - pipe output through the pager.
3283 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3284 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3285 pipe to the pager (restoring the output filehandles if this fails). If this
3286 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3287 set C<$signal>, sending us back into the debugger.
3289 We then trim off the pipe symbols and C<redo> the command loop at the
3290 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3295 # || - run command in the pager, with output to DB::OUT.
3296 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
3297 if ( $pager =~ /^\|/ ) {
3299 # Default pager is into a pipe. Redirect I/O.
3300 open( SAVEOUT, ">&STDOUT" )
3301 || &warn("Can't save STDOUT");
3302 open( STDOUT, ">&OUT" )
3303 || &warn("Can't redirect STDOUT");
3304 } ## end if ($pager =~ /^\|/)
3307 # Not into a pipe. STDOUT is safe.
3308 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3311 # Fix up environment to record we have less if so.
3314 unless ( $piped = open( OUT, $pager ) ) {
3316 # Couldn't open pipe to pager.
3317 &warn("Can't pipe output to '$pager'");
3318 if ( $pager =~ /^\|/ ) {
3320 # Redirect I/O back again.
3321 open( OUT, ">&STDOUT" ) # XXX: lost message
3322 || &warn("Can't restore DB::OUT");
3323 open( STDOUT, ">&SAVEOUT" )
3324 || &warn("Can't restore STDOUT");
3326 } ## end if ($pager =~ /^\|/)
3329 # Redirect I/O. STDOUT already safe.
3330 open( OUT, ">&STDOUT" ) # XXX: lost message
3331 || &warn("Can't restore DB::OUT");
3334 } ## end unless ($piped = open(OUT,...
3336 # Set up broken-pipe handler if necessary.
3337 $SIG{PIPE} = \&DB::catch
3339 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
3342 # Save current filehandle, and put it back.
3343 $selected = select(OUT);
3344 # Don't put it back if pager was a pipe.
3345 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
3347 # Trim off the pipe symbols and run the command now.
3348 $cmd =~ s#\A\|+\s*##;
3352 =head3 END OF COMMAND PARSING
3354 Anything left in C<$cmd> at this point is a Perl expression that we want to
3355 evaluate. We'll always evaluate in the user's context, and fully qualify
3356 any variables we might want to address in the C<DB> package.
3360 # t - turn trace on.
3361 if ($cmd =~ s#\At\s+(\d+)?#\$DB::trace |= 1;\n#) {
3363 $trace_to_depth = $trace_arg ? $stack_depth||0 + $1 : 1E9;
3366 # s - single-step. Remember the last command was 's'.
3367 if ($cmd =~ s/\As\s/\$DB::single = 1;\n/) {
3371 # n - single-step, but not into subs. Remember last command
3373 if ($cmd =~ s#\An\s#\$DB::single = 2;\n#) {
3379 # Make sure the flag that says "the debugger's running" is
3380 # still on, to make sure we get control again.
3381 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3383 # Run *our* eval that executes in the caller's context.
3386 # Turn off the one-time-dump stuff now.
3388 $onetimeDump = undef;
3389 $onetimedumpDepth = undef;
3391 elsif ( $term_pid == $$ ) {
3392 eval { # May run under miniperl, when not available...
3397 # XXX If this is the master pid, print a newline.
3400 } ## end while (($term || &setterm...
3402 =head3 POST-COMMAND PROCESSING
3404 After each command, we check to see if the command output was piped anywhere.
3405 If so, we go through the necessary code to unhook the pipe and go back to
3406 our standard filehandles for input and output.
3412 # At the end of every command:
3415 # Unhook the pipe mechanism now.
3416 if ( $pager =~ /^\|/ ) {
3418 # No error from the child.
3421 # we cannot warn here: the handle is missing --tchrist
3422 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
3424 # most of the $? crud was coping with broken cshisms
3425 # $? is explicitly set to 0, so this never runs.
3427 print SAVEOUT "Pager '$pager' failed: ";
3429 print SAVEOUT "shell returned -1\n";
3432 print SAVEOUT ( $? & 127 )
3433 ? " (SIG#" . ( $? & 127 ) . ")"
3434 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3437 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3441 # Reopen filehandle for our output (if we can) and
3442 # restore STDOUT (if we can).
3443 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3444 open( STDOUT, ">&SAVEOUT" )
3445 || &warn("Can't restore STDOUT");
3447 # Turn off pipe exception handler if necessary.
3448 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
3450 # Will stop ignoring SIGPIPE if done like nohup(1)
3451 # does SIGINT but Perl doesn't give us a choice.
3452 } ## end if ($pager =~ /^\|/)
3455 # Non-piped "pager". Just restore STDOUT.
3456 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3459 # Close filehandle pager was using, restore the normal one
3462 select($selected), $selected = "" unless $selected eq "";
3466 } ## end if ($piped)
3469 =head3 COMMAND LOOP TERMINATION
3471 When commands have finished executing, we come here. If the user closed the
3472 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3473 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3474 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3475 The interpreter will then execute the next line and then return control to us
3480 # No more commands? Quit.
3481 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
3483 # Evaluate post-prompt commands.
3484 foreach $evalarg (@$post) {
3487 } # if ($single || $signal)
3489 # Put the user's globals back where you found them.
3490 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3494 # The following code may be executed now:
3499 C<sub> is called whenever a subroutine call happens in the program being
3500 debugged. The variable C<$DB::sub> contains the name of the subroutine
3503 The core function of this subroutine is to actually call the sub in the proper
3504 context, capturing its output. This of course causes C<DB::DB> to get called
3505 again, repeating until the subroutine ends and returns control to C<DB::sub>
3506 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3507 return value, and returns its captured copy of the return value as its own
3508 return value. The value then feeds back into the program being debugged as if
3509 C<DB::sub> hadn't been there at all.
3511 C<sub> does all the work of printing the subroutine entry and exit messages
3512 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3513 and also prints the return value if needed (for the C<r> command and if
3514 the 16 bit is set in C<$frame>).
3516 It also tracks the subroutine call depth by saving the current setting of
3517 C<$single> in the C<@stack> package global; if this exceeds the value in
3518 C<$deep>, C<sub> automatically turns on printing of the current depth by
3519 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
3520 of stop/don't stop on entry to subs set as it currently is set.
3522 =head3 C<caller()> support
3524 If C<caller()> is called from the package C<DB>, it provides some
3525 additional data, in the following order:
3531 The package name the sub was in
3533 =item * C<$filename>
3535 The filename it was defined in
3539 The line number it was defined on
3541 =item * C<$subroutine>
3543 The subroutine name; C<(eval)> if an C<eval>().
3547 1 if it has arguments, 0 if not
3549 =item * C<$wantarray>
3551 1 if array context, 0 if scalar context
3553 =item * C<$evaltext>
3555 The C<eval>() text, if any (undefined for C<eval BLOCK>)
3557 =item * C<$is_require>
3559 frame was created by a C<use> or C<require> statement
3563 pragma information; subject to change between versions
3567 pragma information; subject to change between versions
3569 =item * C<@DB::args>
3571 arguments with which the subroutine was invoked
3579 # We need to fully qualify the name ("DB::sub") to make "use strict;"
3580 # happy. -- Shlomi Fish
3582 # Do not use a regex in this subroutine -> results in corrupted memory
3583 # See: [perl #66110]
3585 # lock ourselves under threads
3588 # Whether or not the autoloader was running, a scalar to put the
3589 # sub's return value in (if needed), and an array to put the sub's
3590 # return value in (if needed).
3591 my ( $al, $ret, @ret ) = "";
3592 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
3593 print "creating new thread\n";
3596 # If the last ten characters are '::AUTOLOAD', note we've traced
3597 # into AUTOLOAD for $sub.
3598 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3600 $al = " for $$sub" if defined $$sub;
3603 # We stack the stack pointer and then increment it to protect us
3604 # from a situation that might unwind a whole bunch of call frames
3605 # at once. Localizing the stack pointer means that it will automatically
3606 # unwind the same amount when multiple stack frames are unwound.
3607 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3610 $#stack = $stack_depth;
3612 # Save current single-step setting.
3613 $stack[-1] = $single;
3615 # Turn off all flags except single-stepping.
3618 # If we've gotten really deeply recursed, turn on the flag that will
3619 # make us stop with the 'deep recursion' message.
3620 $single |= 4 if $stack_depth == $deep;
3622 # If frame messages are on ...
3624 $frame & 4 # Extended frame entry message
3626 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3628 # Why -1? But it works! :-(
3629 # Because print_trace will call add 1 to it and then call
3630 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3632 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3634 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3636 # standard frame entry message
3640 # Determine the sub's return type, and capture appropriately.
3643 # Called in array context. call sub and capture output.
3644 # DB::DB will recursively get control again if appropriate; we'll come
3645 # back here when the sub is finished.
3651 # Pop the single-step value back off the stack.
3652 $single |= $stack[ $stack_depth-- ];
3654 # Check for exit trace messages...
3656 $frame & 4 # Extended exit message
3658 print_lineinfo( ' ' x $stack_depth, "out " ),
3659 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3661 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3663 # Standard exit message
3667 # Print the return info if we need to.
3668 if ( $doret eq $stack_depth or $frame & 16 ) {
3670 # Turn off output record separator.
3672 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3674 # Indent if we're printing because of $frame tracing.
3675 print $fh ' ' x $stack_depth if $frame & 16;
3677 # Print the return value.
3678 print $fh "list context return from $sub:\n";
3679 dumpit( $fh, \@ret );
3681 # And don't print it again.
3683 } ## end if ($doret eq $stack_depth...
3684 # And we have to return the return value now.
3686 } ## end if (wantarray)
3690 if ( defined wantarray ) {
3692 # Save the value if it's wanted at all.
3697 # Void return, explicitly.
3702 # Pop the single-step value off the stack.
3703 $single |= $stack[ $stack_depth-- ];
3705 # If we're doing exit messages...
3707 $frame & 4 # Extended messages
3709 print_lineinfo( ' ' x $stack_depth, "out " ),
3710 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3712 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3718 # If we are supposed to show the return value... same as before.
3719 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
3721 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3722 print $fh ( ' ' x $stack_depth ) if $frame & 16;
3725 ? "scalar context return from $sub: "
3726 : "void context return from $sub\n"
3728 dumpit( $fh, $ret ) if defined wantarray;
3730 } ## end if ($doret eq $stack_depth...
3732 # Return the appropriate scalar value.
3734 } ## end else [ if (wantarray)
3741 # lock ourselves under threads
3744 # Whether or not the autoloader was running, a scalar to put the
3745 # sub's return value in (if needed), and an array to put the sub's
3746 # return value in (if needed).
3747 my ( $al, $ret, @ret ) = "";
3748 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3749 print "creating new thread\n";
3752 # If the last ten characters are C'::AUTOLOAD', note we've traced
3753 # into AUTOLOAD for $sub.
3754 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3758 # We stack the stack pointer and then increment it to protect us
3759 # from a situation that might unwind a whole bunch of call frames
3760 # at once. Localizing the stack pointer means that it will automatically
3761 # unwind the same amount when multiple stack frames are unwound.
3762 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3765 $#stack = $stack_depth;
3767 # Save current single-step setting.
3768 $stack[-1] = $single;
3770 # Turn off all flags except single-stepping.
3773 # If we've gotten really deeply recursed, turn on the flag that will
3774 # make us stop with the 'deep recursion' message.
3775 $single |= 4 if $stack_depth == $deep;
3777 # If frame messages are on ...
3779 $frame & 4 # Extended frame entry message
3781 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3783 # Why -1? But it works! :-(
3784 # Because print_trace will call add 1 to it and then call
3785 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3787 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3789 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3791 # standard frame entry message
3795 # Pop the single-step value back off the stack.
3796 $single |= $stack[ $stack_depth-- ];
3798 # call the original lvalue sub.
3802 # Abstracting common code from multiple places elsewhere:
3803 sub depth_print_lineinfo {
3804 my $always_print = shift;
3806 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth);
3809 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
3811 In Perl 5.8.0, there was a major realignment of the commands and what they did,
3812 Most of the changes were to systematize the command structure and to eliminate
3813 commands that threw away user input without checking.
3815 The following sections describe the code added to make it easy to support
3816 multiple command sets with conflicting command names. This section is a start
3817 at unifying all command processing to make it simpler to develop commands.
3819 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
3820 number, and C<$dbline> (the current line) as arguments.
3822 Support functions in this section which have multiple modes of failure C<die>
3823 on error; the rest simply return a false value.
3825 The user-interface functions (all of the C<cmd_*> functions) just output
3830 The C<%set> hash defines the mapping from command letter to subroutine
3833 C<%set> is a two-level hash, indexed by set name and then by command name.
3834 Note that trying to set the CommandSet to C<foobar> simply results in the
3835 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
3844 'A' => 'pre580_null',
3846 'B' => 'pre580_null',
3847 'd' => 'pre580_null',
3850 'M' => 'pre580_null',
3852 'o' => 'pre580_null',
3858 '<' => 'pre590_prepost',
3859 '<<' => 'pre590_prepost',
3860 '>' => 'pre590_prepost',
3861 '>>' => 'pre590_prepost',
3862 '{' => 'pre590_prepost',
3863 '{{' => 'pre590_prepost',
3867 my %breakpoints_data;
3869 sub _has_breakpoint_data_ref {
3870 my ($filename, $line) = @_;
3873 exists( $breakpoints_data{$filename} )
3875 exists( $breakpoints_data{$filename}{$line} )
3879 sub _get_breakpoint_data_ref {
3880 my ($filename, $line) = @_;
3882 return ($breakpoints_data{$filename}{$line} ||= +{});
3885 sub _delete_breakpoint_data_ref {
3886 my ($filename, $line) = @_;
3888 delete($breakpoints_data{$filename}{$line});
3889 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) {
3890 delete($breakpoints_data{$filename});
3896 sub _set_breakpoint_enabled_status {
3897 my ($filename, $line, $status) = @_;
3899 _get_breakpoint_data_ref($filename, $line)->{'enabled'} =
3906 sub _enable_breakpoint_temp_enabled_status {
3907 my ($filename, $line) = @_;
3909 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1;
3914 sub _cancel_breakpoint_temp_enabled_status {
3915 my ($filename, $line) = @_;
3917 my $ref = _get_breakpoint_data_ref($filename, $line);
3919 delete ($ref->{'temp_enabled'});
3922 _delete_breakpoint_data_ref($filename, $line);
3928 sub _is_breakpoint_enabled {
3929 my ($filename, $line) = @_;
3931 my $data_ref = _get_breakpoint_data_ref($filename, $line);
3932 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'});
3935 =head2 C<cmd_wrapper()> (API)
3937 C<cmd_wrapper()> allows the debugger to switch command sets
3938 depending on the value of the C<CommandSet> option.
3940 It tries to look up the command in the C<%set> package-level I<lexical>
3941 (which means external entities can't fiddle with it) and create the name of
3942 the sub to call based on the value found in the hash (if it's there). I<All>
3943 of the commands to be handled in a set have to be added to C<%set>; if they
3944 aren't found, the 5.8.0 equivalent is called (if there is one).
3946 This code uses symbolic references.
3953 my $dblineno = shift;
3955 # Assemble the command subroutine's name by looking up the
3956 # command set and command name in %set. If we can't find it,
3957 # default to the older version of the command.
3959 . ( $set{$CommandSet}{$cmd}
3960 || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) );
3962 # Call the command subroutine, call it by name.
3963 return __PACKAGE__->can($call)->( $cmd, $line, $dblineno );
3964 } ## end sub cmd_wrapper
3966 =head3 C<cmd_a> (command)
3968 The C<a> command handles pre-execution actions. These are associated with a
3969 particular line, so they're stored in C<%dbline>. We default to the current
3970 line if none is specified.
3976 my $line = shift || ''; # [.|line] expr
3979 # If it's dot (here), or not all digits, use the current line.
3980 $line =~ s/^(\.|(?:[^\d]))/$dbline/;
3982 # Should be a line number followed by an expression.
3983 if ( $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
3984 my ( $lineno, $expr ) = ( $1, $2 );
3986 # If we have an expression ...
3987 if ( length $expr ) {
3989 # ... but the line isn't breakable, complain.
3990 if ( $dbline[$lineno] == 0 ) {
3992 "Line $lineno($dbline[$lineno]) does not have an action?\n";
3996 # It's executable. Record that the line has an action.
3997 $had_breakpoints{$filename} |= 2;
3999 # Remove any action, temp breakpoint, etc.
4000 $dbline{$lineno} =~ s/\0[^\0]*//;
4002 # Add the action to the line.
4003 $dbline{$lineno} .= "\0" . action($expr);
4005 _set_breakpoint_enabled_status($filename, $lineno, 1);
4007 } ## end if (length $expr)
4008 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
4013 "Adding an action requires an optional lineno and an expression\n"
4018 =head3 C<cmd_A> (command)
4020 Delete actions. Similar to above, except the delete code is in a separate
4021 subroutine, C<delete_action>.
4027 my $line = shift || '';
4031 $line =~ s/^\./$dbline/;
4033 # Call delete_action with a null param to delete them all.
4034 # The '1' forces the eval to be true. It'll be false only
4035 # if delete_action blows up for some reason, in which case
4036 # we print $@ and get out.
4037 if ( $line eq '*' ) {
4038 eval { &delete_action(); 1 } or print $OUT $@ and return;
4041 # There's a real line number. Pass it to delete_action.
4042 # Error trapping is as above.
4043 elsif ( $line =~ /^(\S.*)/ ) {
4044 eval { &delete_action($1); 1 } or print $OUT $@ and return;
4047 # Swing and a miss. Bad syntax.
4050 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4054 =head3 C<delete_action> (API)
4056 C<delete_action> accepts either a line number or C<undef>. If a line number
4057 is specified, we check for the line being executable (if it's not, it
4058 couldn't have had an action). If it is, we just take the action off (this
4059 will get any kind of an action, including breakpoints).
4065 if ( defined($i) ) {
4068 die "Line $i has no action .\n" if $dbline[$i] == 0;
4070 # Nuke whatever's there.
4071 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4072 delete $dbline{$i} if $dbline{$i} eq '';
4075 print $OUT "Deleting all actions...\n";
4076 for my $file ( keys %had_breakpoints ) {
4077 local *dbline = $main::{ '_<' . $file };
4080 for $i (1 .. $max) {
4081 if ( defined $dbline{$i} ) {
4082 $dbline{$i} =~ s/\0[^\0]*//;
4083 delete $dbline{$i} if $dbline{$i} eq '';
4085 unless ( $had_breakpoints{$file} &= ~2 ) {
4086 delete $had_breakpoints{$file};
4088 } ## end for ($i = 1 .. $max)
4089 } ## end for my $file (keys %had_breakpoints)
4090 } ## end else [ if (defined($i))
4091 } ## end sub delete_action
4093 =head3 C<cmd_b> (command)
4095 Set breakpoints. Since breakpoints can be set in so many places, in so many
4096 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4097 we try to parse the command type, and then shuttle it off to an appropriate
4098 subroutine to actually do the work of setting the breakpoint in the right
4105 my $line = shift; # [.|line] [cond]
4108 # Make . the current line number if it's there..
4109 $line =~ s/^\.(\s|\z)/$dbline$1/;
4111 # No line number, no condition. Simple break on current line.
4112 if ( $line =~ /^\s*$/ ) {
4113 &cmd_b_line( $dbline, 1 );
4116 # Break on load for a file.
4117 elsif ( $line =~ /^load\b\s*(.*)/ ) {
4123 # b compile|postpone <some sub> [<condition>]
4124 # The interpreter actually traps this one for us; we just put the
4125 # necessary condition in the %postponed hash.
4126 elsif ( $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4128 # Capture the condition if there is one. Make it true if none.
4129 my $cond = length $3 ? $3 : '1';
4131 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
4132 # if it was 'compile'.
4133 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
4135 # De-Perl4-ify the name - ' separators to ::.
4136 $subname =~ s/\'/::/g;
4138 # Qualify it into the current package unless it's already qualified.
4139 $subname = "${package}::" . $subname unless $subname =~ /::/;
4141 # Add main if it starts with ::.
4142 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4144 # Save the break type for this sub.
4145 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
4146 } ## end elsif ($line =~ ...
4147 # b <filename>:<line> [<condition>]
4148 elsif ($line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) {
4149 my ($filename, $line_num, $cond) = ($1, $2, $3);
4150 cmd_b_filename_line(
4153 (length($cond) ? $cond : '1'),
4156 # b <sub name> [<condition>]
4157 elsif ( $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4161 my $cond = length $2 ? $2 : '1';
4162 &cmd_b_sub( $subname, $cond );
4165 # b <line> [<condition>].
4166 elsif ( $line =~ /^(\d*)\s*(.*)/ ) {
4168 # Capture the line. If none, it's the current line.
4169 $line = $1 || $dbline;
4171 # If there's no condition, make it '1'.
4172 my $cond = length $2 ? $2 : '1';
4175 &cmd_b_line( $line, $cond );
4178 # Line didn't make sense.
4180 print "confused by line($line)?\n";
4184 =head3 C<break_on_load> (API)
4186 We want to break when this file is loaded. Mark this file in the
4187 C<%break_on_load> hash, and note that it has a breakpoint in
4188 C<%had_breakpoints>.
4194 $break_on_load{$file} = 1;
4195 $had_breakpoints{$file} |= 1;
4198 =head3 C<report_break_on_load> (API)
4200 Gives us an array of filenames that are set to break on load. Note that
4201 only files with break-on-load are in here, so simply showing the keys
4206 sub report_break_on_load {
4207 sort keys %break_on_load;
4210 =head3 C<cmd_b_load> (command)
4212 We take the file passed in and try to find it in C<%INC> (which maps modules
4213 to files they came from). We mark those files for break-on-load via
4214 C<break_on_load> and then report that it was done.
4222 # This is a block because that way we can use a redo inside it
4223 # even without there being any looping structure at all outside it.
4226 # Save short name and full path if found.
4228 push @files, $::INC{$file} if $::INC{$file};
4230 # Tack on .pm and do it again unless there was a '.' in the name
4232 $file .= '.pm', redo unless $file =~ /\./;
4235 # Do the real work here.
4236 break_on_load($_) for @files;
4238 # All the files that have break-on-load breakpoints.
4239 @files = report_break_on_load;
4241 # Normalize for the purposes of our printing this.
4244 print $OUT "Will stop on load of '@files'.\n";
4245 } ## end sub cmd_b_load
4247 =head3 C<$filename_error> (API package global)
4249 Several of the functions we need to implement in the API need to work both
4250 on the current file and on other files. We don't want to duplicate code, so
4251 C<$filename_error> is used to contain the name of the file that's being
4252 worked on (if it's not the current one).
4254 We can now build functions in pairs: the basic function works on the current
4255 file, and uses C<$filename_error> as part of its error message. Since this is
4256 initialized to C<"">, no filename will appear when we are working on the
4259 The second function is a wrapper which does the following:
4265 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4269 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4273 Calls the first function.
4275 The first function works on the I<current> file (i.e., the one we changed to),
4276 and prints C<$filename_error> in the error message (the name of the other file)
4277 if it needs to. When the functions return, C<*dbline> is restored to point
4278 to the actual current file (the one we're executing in) and
4279 C<$filename_error> is restored to C<"">. This restores everything to
4280 the way it was before the second function was called at all.
4282 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4289 use vars qw($filename_error);
4290 $filename_error = '';
4292 =head3 breakable_line(from, to) (API)
4294 The subroutine decides whether or not a line in the current file is breakable.
4295 It walks through C<@dbline> within the range of lines specified, looking for
4296 the first line that is breakable.
4298 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4299 first line I<after> C<$to> that's breakable, if there is one.
4301 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4302 first line I<before> C<$to> that's breakable, if there is one.
4306 sub breakable_line {
4308 my ( $from, $to ) = @_;
4310 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4313 # If there are at least 2 arguments, we're trying to search a range.
4316 # $delta is positive for a forward search, negative for a backward one.
4317 my $delta = $from < $to ? +1 : -1;
4319 # Keep us from running off the ends of the file.
4320 my $limit = $delta > 0 ? $#dbline : 1;
4322 # Clever test. If you're a mathematician, it's obvious why this
4323 # test works. If not:
4324 # If $delta is positive (going forward), $limit will be $#dbline.
4325 # If $to is less than $limit, ($limit - $to) will be positive, times
4326 # $delta of 1 (positive), so the result is > 0 and we should use $to
4327 # as the stopping point.
4329 # If $to is greater than $limit, ($limit - $to) is negative,
4330 # times $delta of 1 (positive), so the result is < 0 and we should
4331 # use $limit ($#dbline) as the stopping point.
4333 # If $delta is negative (going backward), $limit will be 1.
4334 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4335 # (negative) so the result is > 0, and we use $to as the stopping
4338 # If $to is less than zero, ($limit - $to) will be positive,
4339 # times $delta of -1 (negative), so the result is not > 0, and
4340 # we use $limit (1) as the stopping point.
4342 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4343 # (negative), still giving zero; the result is not > 0, and
4344 # we use $limit (1) as the stopping point.
4346 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4347 # (negative), giving a positive (>0) value, so we'll set $limit to
4350 $limit = $to if ( $limit - $to ) * $delta > 0;
4352 # The real search loop.
4353 # $i starts at $from (the point we want to start searching from).
4354 # We move through @dbline in the appropriate direction (determined
4355 # by $delta: either -1 (back) or +1 (ahead).
4356 # We stay in as long as we haven't hit an executable line
4357 # ($dbline[$i] == 0 means not executable) and we haven't reached
4358 # the limit yet (test similar to the above).
4359 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4361 } ## end if (@_ >= 2)
4363 # If $i points to a line that is executable, return that.
4364 return $i unless $dbline[$i] == 0;
4366 # Format the message and print it: no breakable lines in range.
4367 my ( $pl, $upto ) = ( '', '' );
4368 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4370 # If there's a filename in filename_error, we'll see it.
4372 die "Line$pl $from$upto$filename_error not breakable\n";
4373 } ## end sub breakable_line
4375 =head3 breakable_line_in_filename(file, from, to) (API)
4377 Like C<breakable_line>, but look in another file.
4381 sub breakable_line_in_filename {
4383 # Capture the file name.
4386 # Swap the magic line array over there temporarily.
4387 local *dbline = $main::{ '_<' . $f };
4389 # If there's an error, it's in this other file.
4390 local $filename_error = " of '$f'";
4392 # Find the breakable line.
4395 # *dbline and $filename_error get restored when this block ends.
4397 } ## end sub breakable_line_in_filename
4399 =head3 break_on_line(lineno, [condition]) (API)
4401 Adds a breakpoint with the specified condition (or 1 if no condition was
4402 specified) to the specified line. Dies if it can't.
4407 my ( $i, $cond ) = @_;
4409 # Always true if no condition supplied.
4410 $cond = 1 unless @_ >= 2;
4416 # Woops, not a breakable line. $filename_error allows us to say
4417 # if it was in a different file.
4418 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4420 # Mark this file as having breakpoints in it.
4421 $had_breakpoints{$filename} |= 1;
4423 # If there is an action or condition here already ...
4424 if ( $dbline{$i} ) {
4426 # ... swap this condition for the existing one.
4427 $dbline{$i} =~ s/^[^\0]*/$cond/;
4431 # Nothing here - just add the condition.
4432 $dbline{$i} = $cond;
4434 _set_breakpoint_enabled_status($filename, $i, 1);
4436 } ## end sub break_on_line
4438 =head3 cmd_b_line(line, [condition]) (command)
4440 Wrapper for C<break_on_line>. Prints the failure message if it
4446 if (not eval { break_on_line(@_); 1 }) {
4448 print $OUT $@ and return;
4452 } ## end sub cmd_b_line
4454 =head3 cmd_b_filename_line(line, [condition]) (command)
4456 Wrapper for C<break_on_filename_line>. Prints the failure message if it
4461 sub cmd_b_filename_line {
4462 if (not eval { break_on_filename_line(@_); 1 }) {
4464 print $OUT $@ and return;
4470 =head3 break_on_filename_line(file, line, [condition]) (API)
4472 Switches to the file specified and then calls C<break_on_line> to set
4477 sub break_on_filename_line {
4478 my ( $f, $i, $cond ) = @_;
4480 # Always true if condition left off.
4481 $cond = 1 unless @_ >= 3;
4483 # Switch the magical hash temporarily.
4484 local *dbline = $main::{ '_<' . $f };
4486 # Localize the variables that break_on_line uses to make its message.
4487 local $filename_error = " of '$f'";
4488 local $filename = $f;
4490 # Add the breakpoint.
4491 break_on_line( $i, $cond );
4492 } ## end sub break_on_filename_line
4494 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4496 Switch to another file, search the range of lines specified for an
4497 executable one, and put a breakpoint on the first one you find.
4501 sub break_on_filename_line_range {
4502 my ( $f, $from, $to, $cond ) = @_;
4504 # Find a breakable line if there is one.
4505 my $i = breakable_line_in_filename( $f, $from, $to );
4507 # Always true if missing.
4508 $cond = 1 unless @_ >= 3;
4510 # Add the breakpoint.
4511 break_on_filename_line( $f, $i, $cond );
4512 } ## end sub break_on_filename_line_range
4514 =head3 subroutine_filename_lines(subname, [condition]) (API)
4516 Search for a subroutine within a given file. The condition is ignored.
4517 Uses C<find_sub> to locate the desired subroutine.
4521 sub subroutine_filename_lines {
4522 my ( $subname, $cond ) = @_;
4524 # Returned value from find_sub() is fullpathname:startline-endline.
4525 # The match creates the list (fullpathname, start, end). Falling off
4526 # the end of the subroutine returns this implicitly.
4527 find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/;
4528 } ## end sub subroutine_filename_lines
4530 =head3 break_subroutine(subname) (API)
4532 Places a break on the first line possible in the specified subroutine. Uses
4533 C<subroutine_filename_lines> to find the subroutine, and
4534 C<break_on_filename_line_range> to place the break.
4538 sub break_subroutine {
4539 my $subname = shift;
4541 # Get filename, start, and end.
4542 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
4543 or die "Subroutine $subname not found.\n";
4546 # Null condition changes to '1' (always true).
4547 my $cond = @_ ? shift(@_) : 1;
4549 # Put a break the first place possible in the range of lines
4550 # that make up this subroutine.
4551 break_on_filename_line_range( $file, $s, $e, $cond );
4552 } ## end sub break_subroutine
4554 =head3 cmd_b_sub(subname, [condition]) (command)
4556 We take the incoming subroutine name and fully-qualify it as best we can.
4560 =item 1. If it's already fully-qualified, leave it alone.
4562 =item 2. Try putting it in the current package.
4564 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
4566 =item 4. If it starts with '::', put it in 'main::'.
4570 After all this cleanup, we call C<break_subroutine> to try to set the
4576 my ( $subname, $cond ) = @_;
4578 # Add always-true condition if we have none.
4579 $cond = 1 unless @_ >= 2;
4581 # If the subname isn't a code reference, qualify it so that
4582 # break_subroutine() will work right.
4583 unless ( ref $subname eq 'CODE' ) {
4586 $subname =~ s/\'/::/g;
4589 # Put it in this package unless it's already qualified.
4590 $subname = "${package}::" . $subname
4591 unless $subname =~ /::/;
4593 # Requalify it into CORE::GLOBAL if qualifying it into this
4594 # package resulted in its not being defined, but only do so
4595 # if it really is in CORE::GLOBAL.
4596 $subname = "CORE::GLOBAL::$s"
4597 if not defined &$subname
4599 and defined &{"CORE::GLOBAL::$s"};
4601 # Put it in package 'main' if it has a leading ::.
4602 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4604 } ## end unless (ref $subname eq 'CODE')
4606 # Try to set the breakpoint.
4607 if (not eval { break_subroutine( $subname, $cond ); 1 }) {
4609 print $OUT $@ and return;
4613 } ## end sub cmd_b_sub
4615 =head3 C<cmd_B> - delete breakpoint(s) (command)
4617 The command mostly parses the command line and tries to turn the argument
4618 into a line spec. If it can't, it uses the current line. It then calls
4619 C<delete_breakpoint> to actually do the work.
4621 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
4622 thereby deleting all the breakpoints.
4629 # No line spec? Use dbline.
4630 # If there is one, use it if it's non-zero, or wipe it out if it is.
4631 my $line = ( $_[0] =~ /\A\./ ) ? $dbline : (shift || '');
4634 # If the line was dot, make the line the current one.
4635 $line =~ s/^\./$dbline/;
4637 # If it's * we're deleting all the breakpoints.
4638 if ( $line eq '*' ) {
4639 if (not eval { delete_breakpoint(); 1 }) {
4644 # If there is a line spec, delete the breakpoint on that line.
4645 elsif ( $line =~ /\A(\S.*)/ ) {
4646 if (not eval { delete_breakpoint( $line || $dbline ); 1 }) {
4650 } ## end elsif ($line =~ /^(\S.*)/)
4655 "Deleting a breakpoint requires a line number, or '*' for all\n"
4662 =head3 delete_breakpoint([line]) (API)
4664 This actually does the work of deleting either a single breakpoint, or all
4667 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
4668 just drop out with a message saying so. If it is, we remove the condition
4669 part of the 'condition\0action' that says there's a breakpoint here. If,
4670 after we've done that, there's nothing left, we delete the corresponding
4671 line in C<%dbline> to signal that no action needs to be taken for this line.
4673 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
4674 which lists all currently-loaded files which have breakpoints. We then look
4675 at each line in each of these files, temporarily switching the C<%dbline>
4676 and C<@dbline> structures to point to the files in question, and do what
4677 we did in the single line case: delete the condition in C<@dbline>, and
4678 delete the key in C<%dbline> if nothing's left.
4680 We then wholesale delete C<%postponed>, C<%postponed_file>, and
4681 C<%break_on_load>, because these structures contain breakpoints for files
4682 and code that haven't been loaded yet. We can just kill these off because there
4683 are no magical debugger structures associated with them.
4687 sub _remove_breakpoint_entry {
4691 _delete_breakpoint_data_ref($fn, $i);
4696 sub _delete_all_breakpoints {
4697 print {$OUT} "Deleting all breakpoints...\n";
4699 # %had_breakpoints lists every file that had at least one
4701 for my $fn ( keys %had_breakpoints ) {
4703 # Switch to the desired file temporarily.
4704 local *dbline = $main::{ '_<' . $fn };
4708 # For all lines in this file ...
4709 for my $i (1 .. $max) {
4711 # If there's a breakpoint or action on this line ...
4712 if ( defined $dbline{$i} ) {
4714 # ... remove the breakpoint.
4715 $dbline{$i} =~ s/\A[^\0]+//;
4716 if ( $dbline{$i} =~ s/\A\0?\z// ) {
4717 # Remove the entry altogether if no action is there.
4718 _remove_breakpoint_entry($fn, $i);
4720 } ## end if (defined $dbline{$i...
4721 } ## end for $i (1 .. $max)
4723 # If, after we turn off the "there were breakpoints in this file"
4724 # bit, the entry in %had_breakpoints for this file is zero,
4725 # we should remove this file from the hash.
4726 if ( not $had_breakpoints{$fn} &= (~1) ) {
4727 delete $had_breakpoints{$fn};
4729 } ## end for my $fn (keys %had_breakpoints)
4731 # Kill off all the other breakpoints that are waiting for files that
4732 # haven't been loaded yet.
4734 undef %postponed_file;
4735 undef %break_on_load;
4740 sub _delete_breakpoint_from_line {
4743 # Woops. This line wasn't breakable at all.
4744 die "Line $i not breakable.\n" if $dbline[$i] == 0;
4746 # Kill the condition, but leave any action.
4747 $dbline{$i} =~ s/\A[^\0]*//;
4749 # Remove the entry entirely if there's no action left.
4750 if ($dbline{$i} eq '') {
4751 _remove_breakpoint_entry($filename, $i);
4757 sub delete_breakpoint {
4760 # If we got a line, delete just that one.
4761 if ( defined($i) ) {
4762 _delete_breakpoint_from_line($i);
4764 # No line; delete them all.
4766 _delete_all_breakpoints();
4772 =head3 cmd_stop (command)
4774 This is meant to be part of the new command API, but it isn't called or used
4775 anywhere else in the debugger. XXX It is probably meant for use in development
4780 sub cmd_stop { # As on ^C, but not signal-safy.
4784 =head3 C<cmd_e> - threads
4786 Display the current thread id:
4790 This could be how (when implemented) to send commands to this thread id (e cmd)
4791 or that thread id (e tid cmd).
4798 unless (exists($INC{'threads.pm'})) {
4799 print "threads not loaded($ENV{PERL5DB_THREADED})
4800 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4802 my $tid = threads->tid;
4803 print "thread id: $tid\n";
4807 =head3 C<cmd_E> - list of thread ids
4809 Display the list of available thread ids:
4813 This could be used (when implemented) to send commands to all threads (E cmd).
4820 unless (exists($INC{'threads.pm'})) {
4821 print "threads not loaded($ENV{PERL5DB_THREADED})
4822 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4824 my $tid = threads->tid;
4825 print "thread ids: ".join(', ',
4826 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
4831 =head3 C<cmd_h> - help command (command)
4833 Does the work of either
4839 Showing all the debugger help
4843 Showing help for a specific command
4850 use vars qw($summary);
4855 # If we have no operand, assume null.
4856 my $line = shift || '';
4858 # 'h h'. Print the long-format help.
4859 if ( $line =~ /\Ah\s*\z/ ) {
4863 # 'h <something>'. Search for the command and print only its help.
4864 elsif ( my ($asked) = $line =~ /\A(\S.*)\z/ ) {
4866 # support long commands; otherwise bogus errors
4867 # happen when you ask for h on <CR> for example
4868 my $qasked = quotemeta($asked); # for searching; we don't
4869 # want to use it as a pattern.
4870 # XXX: finds CR but not <CR>
4872 # Search the help string for the command.
4874 $help =~ /^ # Start of a line
4876 (?:[IB]<) # Optional markup
4877 $qasked # The requested command
4882 # It's there; pull it out and print it.
4886 (?:[IB]<) # Optional markup
4887 $qasked # The command
4888 ([\s\S]*?) # Description line(s)
4889 \n) # End of last description line
4890 (?!\s) # Next line not starting with
4899 # Not found; not a debugger command.
4901 print_help("B<$asked> is not a debugger command.\n");
4903 } ## end elsif ($line =~ /^(\S.*)$/)
4905 # 'h' - print the summary help.
4907 print_help($summary);
4911 =head3 C<cmd_i> - inheritance display
4913 Display the (nested) parentage of the module or object given.
4920 foreach my $isa ( split( /\s+/, $line ) ) {
4929 defined( ${"$_\::VERSION"} )
4930 ? ' ' . ${"$_\::VERSION"}
4932 } @{mro::get_linear_isa(ref($isa) || $isa)}
4938 =head3 C<cmd_l> - list lines (command)
4940 Most of the command is taken up with transforming all the different line
4941 specification syntaxes into 'start-stop'. After that is done, the command
4942 runs a loop over C<@dbline> for the specified range of lines. It handles
4943 the printing of each line and any markers (C<==E<gt>> for current line,
4944 C<b> for break on this line, C<a> for action on this line, C<:> for this
4947 We save the last line listed in the C<$start> global for further listing
4953 my $current_line = $line;
4957 # If this is '-something', delete any spaces after the dash.
4958 $line =~ s/^-\s*$/-/;
4960 # If the line is '$something', assume this is a scalar containing a
4962 if ( $line =~ /^(\$.*)/s ) {
4964 # Set up for DB::eval() - evaluate in *user* context.
4969 # Ooops. Bad scalar.
4971 print {$OUT} "Error: $@\n";
4975 # Good scalar. If it's a reference, find what it points to.
4977 print {$OUT} "Interpreted as: $1 $s\n";
4980 # Call self recursively to really do the command.
4982 } ## end if ($line =~ /^(\$.*)/s)
4984 # l name. Try to find a sub by that name.
4985 elsif ( ($subname) = $line =~ /\A([\':A-Za-z_][\':\w]*(?:\[.*\])?)/s ) {
4989 $subname =~ s/\'/::/;
4991 # Put it in this package unless it starts with ::.
4992 $subname = $package . "::" . $subname unless $subname =~ /::/;
4994 # Put it in CORE::GLOBAL if t doesn't start with :: and
4995 # it doesn't live in this package and it lives in CORE::GLOBAL.
4996 $subname = "CORE::GLOBAL::$s"
4997 if not defined &$subname
4999 and defined &{"CORE::GLOBAL::$s"};
5001 # Put leading '::' names into 'main::'.
5002 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
5004 # Get name:start-stop from find_sub, and break this up at
5006 my @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
5008 # Pull off start-stop.
5009 my $subrange = pop @pieces;
5011 # If the name contained colons, the split broke it up.
5012 # Put it back together.
5013 $file = join( ':', @pieces );
5015 # If we're not in that file, switch over to it.
5016 if ( $file ne $filename ) {
5017 print $OUT "Switching to file '$file'.\n"
5018 unless $slave_editor;
5020 # Switch debugger's magic structures.
5021 *dbline = $main::{ '_<' . $file };
5024 } ## end if ($file ne $filename)
5026 # Subrange is 'start-stop'. If this is less than a window full,
5027 # swap it to 'start+', which will list a window from the start point.
5029 if ( eval($subrange) < -$window ) {
5030 $subrange =~ s/-.*/+/;
5033 # Call self recursively to list the range.
5035 cmd_l( 'l', $subrange );
5036 } ## end if ($subrange)
5040 print $OUT "Subroutine $subname not found.\n";
5042 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
5045 elsif ( $line !~ /\S/ ) {
5047 # Compute new range to list.
5048 $incr = $window - 1;
5049 $line = $start . '-' . ( $start + $incr );
5052 cmd_l( 'l', $line );
5055 # l [start]+number_of_lines
5056 elsif ( my ($new_start, $new_incr) = $line =~ /\A(\d*)\+(\d*)\z/ ) {
5058 # Don't reset start for 'l +nnn'.
5059 $start = $new_start if $new_start;
5061 # Increment for list. Use window size if not specified.
5062 # (Allows 'l +' to work.)
5064 $incr = $window - 1 unless $incr;
5066 # Create a line range we'll understand, and recurse to do it.
5067 $line = $start . '-' . ( $start + $incr );
5068 cmd_l( 'l', $line );
5069 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
5071 # l start-stop or l start,stop
5072 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) {
5074 # Determine end point; use end of file if not specified.
5075 my $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 );
5077 # Go on to the end, and then stop.
5078 $end = $max if $end > $max;
5080 # Determine start line.
5082 $i = $line if $i eq '.';
5086 # If we're running under a slave editor, force it to show the lines.
5087 if ($slave_editor) {
5088 print $OUT "\032\032$filename:$i:0\n";
5092 # We're doing it ourselves. We want to show the line and special
5094 # - the current line in execution
5095 # - whether a line is breakable or not
5096 # - whether a line has a break or not
5097 # - whether a line has an action or not
5099 for ( ; $i <= $end ; $i++ ) {
5101 # Check for breakpoints and actions.
5102 my ( $stop, $action );
5103 ( $stop, $action ) = split( /\0/, $dbline{$i} )
5106 # ==> if this is the current line in execution,
5107 # : if it's breakable.
5109 ( $i == $current_line and $filename eq $filename_ini )
5111 : ( $dbline[$i] + 0 ? ':' : ' ' );
5113 # Add break and action indicators.
5114 $arrow .= 'b' if $stop;
5115 $arrow .= 'a' if $action;
5118 print $OUT "$i$arrow\t", $dbline[$i];
5120 # Move on to the next line. Drop out on an interrupt.
5121 $i++, last if $signal;
5122 } ## end for (; $i <= $end ; $i++)
5124 # Line the prompt up; print a newline if the last line listed
5125 # didn't have a newline.
5126 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/;
5127 } ## end else [ if ($slave_editor)
5129 # Save the point we last listed to in case another relative 'l'
5130 # command is desired. Don't let it run off the end.
5132 $start = $max if $start > $max;
5133 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
5136 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5138 To list breakpoints, the command has to look determine where all of them are
5139 first. It starts a C<%had_breakpoints>, which tells us what all files have
5140 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5141 magic source and breakpoint data structures) to the file, and then look
5142 through C<%dbline> for lines with breakpoints and/or actions, listing them
5143 out. We look through C<%postponed> not-yet-compiled subroutines that have
5144 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5145 that have breakpoints.
5147 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5154 # If no argument, list everything. Pre-5.8.0 version always lists
5156 my $arg = shift || 'abw';
5157 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
5159 # See what is wanted.
5160 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0;
5161 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0;
5162 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0;
5164 # Breaks and actions are found together, so we look in the same place
5166 if ( $break_wanted or $action_wanted ) {
5168 # Look in all the files with breakpoints...
5169 for my $file ( keys %had_breakpoints ) {
5171 # Temporary switch to this file.
5172 local *dbline = $main::{ '_<' . $file };
5174 # Set up to look through the whole file.
5176 my $was; # Flag: did we print something
5179 # For each line in the file ...
5180 for my $i (1 .. $max) {
5182 # We've got something on this line.
5183 if ( defined $dbline{$i} ) {
5185 # Print the header if we haven't.
5186 print $OUT "$file:\n" unless $was++;
5189 print $OUT " $i:\t", $dbline[$i];
5191 # Pull out the condition and the action.
5192 my ( $stop, $action ) = split( /\0/, $dbline{$i} );
5194 # Print the break if there is one and it's wanted.
5195 print $OUT " break if (", $stop, ")\n"
5199 # Print the action if there is one and it's wanted.
5200 print $OUT " action: ", $action, "\n"
5204 # Quit if the user hit interrupt.
5206 } ## end if (defined $dbline{$i...
5207 } ## end for my $i (1 .. $max)
5208 } ## end for my $file (keys %had_breakpoints)
5209 } ## end if ($break_wanted or $action_wanted)
5211 # Look for breaks in not-yet-compiled subs:
5212 if ( %postponed and $break_wanted ) {
5213 print $OUT "Postponed breakpoints in subroutines:\n";
5215 for $subname ( keys %postponed ) {
5216 print $OUT " $subname\t$postponed{$subname}\n";
5219 } ## end if (%postponed and $break_wanted)
5221 # Find files that have not-yet-loaded breaks:
5222 my @have = map { # Combined keys
5223 keys %{ $postponed_file{$_} }
5224 } keys %postponed_file;
5226 # If there are any, list them.
5227 if ( @have and ( $break_wanted or $action_wanted ) ) {
5228 print $OUT "Postponed breakpoints in files:\n";
5229 for my $file ( keys %postponed_file ) {
5230 my $db = $postponed_file{$file};
5231 print $OUT " $file:\n";
5232 for my $line ( sort { $a <=> $b } keys %$db ) {
5233 print $OUT " $line:\n";
5234 my ( $stop, $action ) = split( /\0/, $$db{$line} );
5235 print $OUT " break if (", $stop, ")\n"
5238 print $OUT " action: ", $action, "\n"
5242 } ## end for $line (sort { $a <=>...
5244 } ## end for $file (keys %postponed_file)
5245 } ## end if (@have and ($break_wanted...
5246 if ( %break_on_load and $break_wanted ) {
5247 print {$OUT} "Breakpoints on load:\n";
5248 BREAK_ON_LOAD: for my $filename ( keys %break_on_load ) {
5249 print {$OUT} " $filename\n";
5250 last BREAK_ON_LOAD if $signal;
5252 } ## end if (%break_on_load and...
5253 if ($watch_wanted and ( $trace & 2 )) {
5254 print {$OUT} "Watch-expressions:\n" if @to_watch;
5255 TO_WATCH: for my $expr (@to_watch) {
5256 print {$OUT} " $expr\n";
5257 last TO_WATCH if $signal;
5262 =head3 C<cmd_M> - list modules (command)
5264 Just call C<list_modules>.
5274 =head3 C<cmd_o> - options (command)
5276 If this is just C<o> by itself, we list the current settings via
5277 C<dump_option>. If there's a nonblank value following it, we pass that on to
5278 C<parse_options> for processing.
5284 my $opt = shift || ''; # opt[=val]
5286 # Nonblank. Try to parse and process.
5287 if ( $opt =~ /^(\S.*)/ ) {
5291 # Blank. List the current option settings.
5299 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5301 Advises the user that the O command has been renamed.
5306 print $OUT "The old O command is now the o command.\n"; # hint
5307 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5308 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5311 =head3 C<cmd_v> - view window (command)
5313 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5314 move back a few lines to list the selected line in context. Uses C<cmd_l>
5315 to do the actual listing after figuring out the range of line to request.
5319 use vars qw($preview);
5325 # Extract the line to list around. (Astute readers will have noted that
5326 # this pattern will match whether or not a numeric line is specified,
5327 # which means that we'll always enter this loop (though a non-numeric
5328 # argument results in no action at all)).
5329 if ( $line =~ /^(\d*)$/ ) {
5331 # Total number of lines to list (a windowful).
5332 $incr = $window - 1;
5334 # Set the start to the argument given (if there was one).
5337 # Back up by the context amount.
5340 # Put together a linespec that cmd_l will like.
5341 $line = $start . '-' . ( $start + $incr );
5344 cmd_l( 'l', $line );
5345 } ## end if ($line =~ /^(\d*)$/)
5348 =head3 C<cmd_w> - add a watch expression (command)
5350 The 5.8 version of this command adds a watch expression if one is specified;
5351 it does nothing if entered with no operands.
5353 We extract the expression, save it, evaluate it in the user's context, and
5354 save the value. We'll re-evaluate it each time the debugger passes a line,
5355 and will stop (see the code at the top of the command loop) if the value
5356 of any of the expressions changes.
5363 # Null expression if no arguments.
5364 my $expr = shift || '';
5366 # If expression is not null ...
5367 if ( $expr =~ /^(\S.*)/ ) {
5370 push @to_watch, $expr;
5372 # Parameterize DB::eval and call it to get the expression's value
5373 # in the user's context. This version can handle expressions which
5374 # return a list value.
5376 my ($val) = join( ' ', &eval );
5377 $val = ( defined $val ) ? "'$val'" : 'undef';
5379 # Save the current value of the expression.
5380 push @old_watch, $val;
5382 # We are now watching expressions.
5384 } ## end if ($expr =~ /^(\S.*)/)
5386 # You have to give one to get one.
5388 print $OUT "Adding a watch-expression requires an expression\n"; # hint
5392 =head3 C<cmd_W> - delete watch expressions (command)
5394 This command accepts either a watch expression to be removed from the list
5395 of watch expressions, or C<*> to delete them all.
5397 If C<*> is specified, we simply empty the watch expression list and the
5398 watch expression value list. We also turn off the bit that says we've got
5401 If an expression (or partial expression) is specified, we pattern-match
5402 through the expressions and remove the ones that match. We also discard
5403 the corresponding values. If no watch expressions are left, we turn off
5404 the I<watching expressions> bit.
5410 my $expr = shift || '';
5413 if ( $expr eq '*' ) {
5418 print $OUT "Deleting all watch expressions ...\n";
5421 @to_watch = @old_watch = ();
5424 # Delete one of them.
5425 elsif ( $expr =~ /^(\S.*)/ ) {
5427 # Where we are in the list.
5430 # For each expression ...
5431 foreach (@to_watch) {
5432 my $val = $to_watch[$i_cnt];
5434 # Does this one match the command argument?
5435 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
5436 # Yes. Turn it off, and its value too.
5437 splice( @to_watch, $i_cnt, 1 );
5438 splice( @old_watch, $i_cnt, 1 );
5441 } ## end foreach (@to_watch)
5443 # We don't bother to turn watching off because
5444 # a) we don't want to stop calling watchfunction() it it exists
5445 # b) foreach over a null list doesn't do anything anyway
5447 } ## end elsif ($expr =~ /^(\S.*)/)
5449 # No command arguments entered.
5452 "Deleting a watch-expression requires an expression, or '*' for all\n"
5457 ### END of the API section
5459 =head1 SUPPORT ROUTINES
5461 These are general support routines that are used in a number of places
5462 throughout the debugger.
5466 save() saves the user's versions of globals that would mess us up in C<@saved>,
5467 and installs the versions we like better.
5473 # Save eval failure, command failure, extended OS error, output field
5474 # separator, input record separator, output record separator and
5475 # the warning setting.
5476 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
5478 $, = ""; # output field separator is null string
5479 $/ = "\n"; # input record separator is newline
5480 $\ = ""; # output record separator is null string
5481 $^W = 0; # warnings are off
5484 =head2 C<print_lineinfo> - show where we are now
5486 print_lineinfo prints whatever it is that it is handed; it prints it to the
5487 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5488 us to feed line information to a slave editor without messing up the
5493 sub print_lineinfo {
5495 # Make the terminal sensible if we're not the primary debugger.
5496 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5500 } ## end sub print_lineinfo
5502 =head2 C<postponed_sub>
5504 Handles setting postponed breakpoints in subroutines once they're compiled.
5505 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5506 range for the subroutine, then mark the file as having a breakpoint,
5507 temporarily switch the C<*dbline> glob over to the source file, and then
5508 search the given range of lines to find a breakable line. If we find one,
5509 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
5513 # The following takes its argument via $evalarg to preserve current @_
5517 # Get the subroutine name.
5518 my $subname = shift;
5520 # If this is a 'break +<n> if <condition>' ...
5521 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
5523 # If there's no offset, use '+0'.
5524 my $offset = $1 || 0;
5526 # find_sub's value is 'fullpath-filename:start-stop'. It's
5527 # possible that the filename might have colons in it too.
5528 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
5531 # We got the start line. Add the offset '+<n>' from
5532 # $postponed{subname}.
5535 # Switch to the file this sub is in, temporarily.
5536 local *dbline = $main::{ '_<' . $file };
5538 # No warnings, please.
5539 local $^W = 0; # != 0 is magical below
5541 # This file's got a breakpoint in it.
5542 $had_breakpoints{$file} |= 1;
5544 # Last line in file.
5547 # Search forward until we hit a breakable line or get to
5548 # the end of the file.
5549 ++$i until $dbline[$i] != 0 or $i >= $max;
5551 # Copy the breakpoint in and delete it from %postponed.
5552 $dbline{$i} = delete $postponed{$subname};
5555 # find_sub didn't find the sub.
5558 print $OUT "Subroutine $subname not found.\n";
5561 } ## end if ($postponed{$subname...
5562 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
5564 #print $OUT "In postponed_sub for '$subname'.\n";
5565 } ## end sub postponed_sub
5569 Called after each required file is compiled, but before it is executed;
5570 also called if the name of a just-compiled subroutine is a key of
5571 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
5572 etc.) into the just-compiled code.
5574 If this is a C<require>'d file, the incoming parameter is the glob
5575 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
5577 If it's a subroutine, the incoming parameter is the subroutine name.
5583 # If there's a break, process it.
5584 if ($ImmediateStop) {
5586 # Right, we've stopped. Turn it off.
5589 # Enter the command loop when DB::DB gets called.
5593 # If this is a subroutine, let postponed_sub() deal with it.
5594 return &postponed_sub unless ref \$_[0] eq 'GLOB';
5596 # Not a subroutine. Deal with the file.
5597 local *dbline = shift;
5598 my $filename = $dbline;
5599 $filename =~ s/^_<//;
5601 $signal = 1, print $OUT "'$filename' loaded...\n"
5602 if $break_on_load{$filename};
5603 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
5605 # Do we have any breakpoints to put in this file?
5606 return unless $postponed_file{$filename};
5608 # Yes. Mark this file as having breakpoints.
5609 $had_breakpoints{$filename} |= 1;
5611 # "Cannot be done: insufficient magic" - we can't just put the
5612 # breakpoints saved in %postponed_file into %dbline by assigning
5613 # the whole hash; we have to do it one item at a time for the
5614 # breakpoints to be set properly.
5615 #%dbline = %{$postponed_file{$filename}};
5617 # Set the breakpoints, one at a time.
5620 for $key ( keys %{ $postponed_file{$filename} } ) {
5622 # Stash the saved breakpoint into the current file's magic line array.
5623 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
5626 # This file's been compiled; discard the stored breakpoints.
5627 delete $postponed_file{$filename};
5629 } ## end sub postponed
5633 C<dumpit> is the debugger's wrapper around dumpvar.pl.
5635 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
5636 a reference to a variable (the thing to be dumped) as its input.
5638 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
5639 the currently-selected filehandle, thank you very much). The current
5640 values of the package globals C<$single> and C<$trace> are backed up in
5641 lexicals, and they are turned off (this keeps the debugger from trying
5642 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
5643 preserve its current value and it is set to zero to prevent entry/exit
5644 messages from printing, and C<$doret> is localized as well and set to -2 to
5645 prevent return values from being shown.
5647 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
5648 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
5649 installed version in C<@INC>, yours will be used instead. Possible security
5652 It then checks to see if the subroutine C<main::dumpValue> is now defined
5653 it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
5654 localizes the globals necessary for things to be sane when C<main::dumpValue()>
5655 is called, and picks up the variable to be dumped from the parameter list.
5657 It checks the package global C<%options> to see if there's a C<dumpDepth>
5658 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
5659 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
5660 structure: -1 means dump everything.
5662 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
5665 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
5666 and we then return to the caller.
5672 # Save the current output filehandle and switch to the one
5673 # passed in as the first parameter.
5674 my $savout = select(shift);
5676 # Save current settings of $single and $trace, and then turn them off.
5677 my $osingle = $single;
5678 my $otrace = $trace;
5679 $single = $trace = 0;
5681 # XXX Okay, what do $frame and $doret do, again?
5685 # Load dumpvar.pl unless we've already got the sub we need from it.
5686 unless ( defined &main::dumpValue ) {
5687 do 'dumpvar.pl' or die $@;
5690 # If the load succeeded (or we already had dumpvalue()), go ahead
5692 if ( defined &main::dumpValue ) {
5697 my $maxdepth = shift || $option{dumpDepth};
5698 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
5699 &main::dumpValue( $v, $maxdepth );
5700 } ## end if (defined &main::dumpValue)
5702 # Oops, couldn't load dumpvar.pl.
5705 print $OUT "dumpvar.pl not available.\n";
5708 # Reset $single and $trace to their old values.
5712 # Restore the old filehandle.
5716 =head2 C<print_trace>
5718 C<print_trace>'s job is to print a stack trace. It does this via the
5719 C<dump_trace> routine, which actually does all the ferreting-out of the
5720 stack trace data. C<print_trace> takes care of formatting it nicely and
5721 printing it to the proper filehandle.
5729 The filehandle to print to.
5733 How many frames to skip before starting trace.
5737 How many frames to print.
5741 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
5745 The original comment below seems to be noting that the traceback may not be
5746 correct if this routine is called in a tied method.
5750 # Tied method do not create a context, so may get wrong message:
5756 # If this is going to a slave editor, but we're not the primary
5757 # debugger, reset it first.
5759 if $fh eq $LINEINFO # slave editor
5760 and $LINEINFO eq $OUT # normal output
5761 and $term_pid != $$; # not the primary
5763 # Collect the actual trace information to be formatted.
5764 # This is an array of hashes of subroutine call info.
5765 my @sub = dump_trace( $_[0] + 1, $_[1] );
5767 # Grab the "short report" flag from @_.
5768 my $short = $_[2]; # Print short report, next one for sub name
5770 # Run through the traceback info, format it, and print it.
5772 for my $i (0 .. $#sub) {
5774 # Drop out if the user has lost interest and hit control-C.
5777 # Set the separator so arrys print nice.
5780 # Grab and stringify the arguments if they are there.
5782 defined $sub[$i]{args}
5783 ? "(@{ $sub[$i]{args} })"
5786 # Shorten them up if $maxtrace says they're too long.
5787 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
5788 if length $args > $maxtrace;
5790 # Get the file name.
5791 my $file = $sub[$i]{file};
5793 # Put in a filename header if short is off.
5794 $file = $file eq '-e' ? $file : "file '$file'" unless $short;
5796 # Get the actual sub's name, and shorten to $maxtrace's requirement.
5798 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
5800 # Short report uses trimmed file and sub names.
5802 my $sub = @_ >= 4 ? $_[3] : $s;
5803 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
5804 } ## end if ($short)
5806 # Non-short report includes full names.
5808 print $fh "$sub[$i]{context} = $s$args"
5809 . " called from $file"
5810 . " line $sub[$i]{line}\n";
5812 } ## end for my $i (0 .. $#sub)
5813 } ## end sub print_trace
5815 =head2 dump_trace(skip[,count])
5817 Actually collect the traceback information available via C<caller()>. It does
5818 some filtering and cleanup of the data, but mostly it just collects it to
5819 make C<print_trace()>'s job easier.
5821 C<skip> defines the number of stack frames to be skipped, working backwards
5822 from the most current. C<count> determines the total number of frames to
5823 be returned; all of them (well, the first 10^9) are returned if C<count>
5826 This routine returns a list of hashes, from most-recent to least-recent
5827 stack frame. Each has the following keys and values:
5831 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
5833 =item * C<sub> - subroutine name, or C<eval> information
5835 =item * C<args> - undef, or a reference to an array of arguments
5837 =item * C<file> - the file in which this item was defined (if any)
5839 =item * C<line> - the line on which it was defined
5847 # How many levels to skip.
5850 # How many levels to show. (1e9 is a cheap way of saying "all of them";
5851 # it's unlikely that we'll have more than a billion stack frames. If you
5852 # do, you've got an awfully big machine...)
5853 my $count = shift || 1e9;
5855 # We increment skip because caller(1) is the first level *back* from
5856 # the current one. Add $skip to the count of frames so we have a
5857 # simple stop criterion, counting from $skip to $count+$skip.
5861 # These variables are used to capture output from caller();
5862 my ( $p, $file, $line, $sub, $h, $context );
5864 my ( $e, $r, @a, @sub, $args );
5866 # XXX Okay... why'd we do that?
5867 my $nothard = not $frame & 8;
5870 # Do not want to trace this.
5871 my $otrace = $trace;
5874 # Start out at the skip count.
5875 # If we haven't reached the number of frames requested, and caller() is
5876 # still returning something, stay in the loop. (If we pass the requested
5877 # number of stack frames, or we run out - caller() returns nothing - we
5879 # Up the stack frame index to go back one more level each time.
5883 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
5888 # Go through the arguments and save them for later.
5890 for my $arg (@args) {
5892 if ( not defined $arg ) { # undefined parameter
5896 elsif ( $nothard and tied $arg ) { # tied parameter
5899 elsif ( $nothard and $type = ref $arg ) { # reference
5900 push @a, "ref($type)";
5902 else { # can be stringified
5904 "$arg"; # Safe to stringify now - should not call f().
5906 # Backslash any single-quotes or backslashes.
5909 # Single-quote it unless it's a number or a colon-separated
5912 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
5914 # Turn high-bit characters into meta-whatever.
5915 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
5917 # Turn control characters into ^-whatever.
5918 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
5921 } ## end else [ if (not defined $arg)
5922 } ## end for $arg (@args)
5924 # If context is true, this is array (@)context.
5925 # If context is false, this is scalar ($) context.
5926 # If neither, context isn't defined. (This is apparently a 'can't
5928 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
5930 # if the sub has args ($h true), make an anonymous array of the
5932 $args = $h ? [@a] : undef;
5934 # remove trailing newline-whitespace-semicolon-end of line sequence
5935 # from the eval text, if any.
5936 $e =~ s/\n\s*\;\s*\Z// if $e;
5938 # Escape backslashed single-quotes again if necessary.
5939 $e =~ s/([\\\'])/\\$1/g if $e;
5941 # if the require flag is true, the eval text is from a require.
5943 $sub = "require '$e'";
5946 # if it's false, the eval text is really from an eval.
5947 elsif ( defined $r ) {
5951 # If the sub is '(eval)', this is a block eval, meaning we don't
5952 # know what the eval'ed text actually was.
5953 elsif ( $sub eq '(eval)' ) {
5954 $sub = "eval {...}";
5957 # Stick the collected information into @sub as an anonymous hash.
5961 context => $context,
5969 # Stop processing frames if the user hit control-C.
5971 } ## end for ($i = $skip ; $i < ...
5973 # Restore the trace value again.
5976 } ## end sub dump_trace
5980 C<action()> takes input provided as the argument to an add-action command,
5981 either pre- or post-, and makes sure it's a complete command. It doesn't do
5982 any fancy parsing; it just keeps reading input until it gets a string
5983 without a trailing backslash.
5990 while ( $action =~ s/\\$// ) {
5992 # We have a backslash on the end. Read more.
5994 } ## end while ($action =~ s/\\$//)
5996 # Return the assembled action.
6002 This routine mostly just packages up a regular expression to be used
6003 to check that the thing it's being matched against has properly-matched
6006 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
6007 speeds things up by only creating the qr//'ed expression once; if it's
6008 already defined, we don't try to define it again. A speed hack.
6012 use vars qw($balanced_brace_re);
6016 # I hate using globals!
6017 $balanced_brace_re ||= qr{
6020 (?> [^{}] + ) # Non-parens without backtracking
6022 (??{ $balanced_brace_re }) # Group with matching parens
6026 return $_[0] !~ m/$balanced_brace_re/;
6027 } ## end sub unbalanced
6031 C<gets()> is a primitive (very primitive) routine to read continuations.
6032 It was devised for reading continuations for actions.
6033 it just reads more input with C<readline()> and returns it.
6038 &readline("cont: ");
6041 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger
6043 The C<system()> function assumes that it can just go ahead and use STDIN and
6044 STDOUT, but under the debugger, we want it to use the debugger's input and
6047 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes
6048 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
6049 and then puts everything back again.
6055 # We save, change, then restore STDIN and STDOUT to avoid fork() since
6056 # some non-Unix systems can do system() but have problems with fork().
6057 open( SAVEIN, "<&STDIN" ) || &warn("Can't save STDIN");
6058 open( SAVEOUT, ">&STDOUT" ) || &warn("Can't save STDOUT");
6059 open( STDIN, "<&IN" ) || &warn("Can't redirect STDIN");
6060 open( STDOUT, ">&OUT" ) || &warn("Can't redirect STDOUT");
6062 # XXX: using csh or tcsh destroys sigint retvals!
6064 open( STDIN, "<&SAVEIN" ) || &warn("Can't restore STDIN");
6065 open( STDOUT, ">&SAVEOUT" ) || &warn("Can't restore STDOUT");
6069 # most of the $? crud was coping with broken cshisms
6071 &warn( "(Command exited ", ( $? >> 8 ), ")\n" );
6075 "(Command died of SIG#",
6077 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6086 =head1 TTY MANAGEMENT
6088 The subs here do some of the terminal management for multiple debuggers.
6092 Top-level function called when we want to set up a new terminal for use
6095 If the C<noTTY> debugger option was set, we'll either use the terminal
6096 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6097 to find one. If we're a forked debugger, we call C<resetterm> to try to
6098 get a whole new terminal if we can.
6100 In either case, we set up the terminal next. If the C<ReadLine> option was
6101 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6102 the appropriate attributes. We then
6106 use vars qw($ornaments);
6107 use vars qw($rl_attribs);
6111 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6114 require Term::ReadLine;
6116 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6119 my ( $i, $o ) = split $tty, /,/;
6120 $o = $i unless defined $o;
6121 open( IN, "<$i" ) or die "Cannot open TTY '$i' for read: $!";
6122 open( OUT, ">$o" ) or die "Cannot open TTY '$o' for write: $!";
6128 # We don't have a TTY - try to find one via Term::Rendezvous.
6130 require Term::Rendezvous;
6132 # See if we have anything to pass to Term::Rendezvous.
6133 # Use $HOME/.perldbtty$$ if not.
6134 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6136 # Rendezvous and get the filehandles.
6137 my $term_rv = Term::Rendezvous->new( $rv );
6139 $OUT = $term_rv->OUT;
6140 } ## end else [ if ($tty)
6141 } ## end if ($notty)
6143 # We're a daughter debugger. Try to fork off another TTY.
6144 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6148 # If we shouldn't use Term::ReadLine, don't.
6150 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6153 # We're using Term::ReadLine. Get all the attributes for this terminal.
6155 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6157 $rl_attribs = $term->Attribs;
6158 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6159 if defined $rl_attribs->{basic_word_break_characters}
6160 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6161 $rl_attribs->{special_prefixes} = '$@&%';
6162 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6163 $rl_attribs->{completion_function} = \&db_complete;
6164 } ## end else [ if (!$rl)
6166 # Set up the LINEINFO filehandle.
6167 $LINEINFO = $OUT unless defined $LINEINFO;
6168 $lineinfo = $console unless defined $lineinfo;
6174 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6175 $term->SetHistory(@hist);
6178 # XXX Ornaments are turned on unconditionally, which is not
6179 # always a good thing.
6180 ornaments($ornaments) if defined $ornaments;
6182 } ## end sub setterm
6185 $histfile //= option_val("HistFile", undef);
6186 return unless defined $histfile;
6187 open my $fh, "<", $histfile or return;
6198 return unless defined $histfile;
6199 eval { require File::Path } or return;
6200 eval { require File::Basename } or return;
6201 File::Path::mkpath(File::Basename::dirname($histfile));
6202 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6203 $histsize //= option_val("HistSize",100);
6204 my @copy = grep { $_ ne '?' } @hist;
6205 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6206 for ($start .. $#copy) {
6207 print $fh "$copy[$_]\n";
6209 close $fh or die "Could not write '$histfile': $!";
6212 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6214 When the process being debugged forks, or the process invokes a command
6215 via C<system()> which starts a new debugger, we need to be able to get a new
6216 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6217 fight over the terminal, and you can never quite be sure who's going to get the
6218 input you're typing.
6220 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6221 is tasked with doing all the necessary operating system mojo to get a new
6222 TTY (and probably another window) and to direct the new debugger to read and
6225 The debugger provides C<get_fork_TTY> functions which work for TCP
6226 socket servers, X11, OS/2, and Mac OS X. Other systems are not
6227 supported. You are encouraged to write C<get_fork_TTY> functions which
6228 work for I<your> platform and contribute them.
6230 =head3 C<socket_get_fork_TTY>
6234 sub connect_remoteport {
6237 my $socket = IO::Socket::INET->new(
6239 PeerAddr => $remoteport,
6243 die "Unable to connect to remote host: $remoteport\n";
6248 sub socket_get_fork_TTY {
6249 $tty = $LINEINFO = $IN = $OUT = connect_remoteport();
6251 # Do I need to worry about setting $term?
6253 reset_IN_OUT( $IN, $OUT );
6257 =head3 C<xterm_get_fork_TTY>
6259 This function provides the C<get_fork_TTY> function for X11. If a
6260 program running under the debugger forks, a new <xterm> window is opened and
6261 the subsidiary debugger is directed there.
6263 The C<open()> call is of particular note here. We have the new C<xterm>
6264 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6265 command (which prints the device name of the TTY we'll want to use for input
6266 and output to STDOUT, then C<sleep> for a very long time, routing this output
6267 to file number 3. This way we can simply read from the <XT> filehandle (which
6268 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6270 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6275 sub xterm_get_fork_TTY {
6276 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6278 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6281 # Get the output from 'tty' and clean it up a little.
6285 $pidprompt = ''; # Shown anyway in titlebar
6287 # We need $term defined or we can not switch to the newly created xterm
6288 if ($tty ne '' && !defined $term) {
6289 require Term::ReadLine;
6291 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6294 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6297 # There's our new TTY.
6299 } ## end sub xterm_get_fork_TTY
6301 =head3 C<os2_get_fork_TTY>
6303 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6307 # This example function resets $IN, $OUT itself
6309 sub os2_get_fork_TTY { # A simplification of the following (and works without):
6311 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6312 my %opt = ( title => "Daughter Perl debugger $pids $name",
6313 ($rl ? (read_by_key => 1) : ()) );
6314 require OS2::Process;
6315 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
6317 $pidprompt = ''; # Shown anyway in titlebar
6318 reset_IN_OUT($in, $out);
6320 return ''; # Indicate that reset_IN_OUT is called
6321 } ## end sub os2_get_fork_TTY
6323 =head3 C<macosx_get_fork_TTY>
6325 The Mac OS X version uses AppleScript to tell Terminal.app to create
6330 # Notes about Terminal.app's AppleScript support,
6331 # (aka things that might break in future OS versions).
6333 # The "do script" command doesn't return a reference to the new window
6334 # it creates, but since it appears frontmost and windows are enumerated
6335 # front to back, we can use "first window" === "window 1".
6337 # Since "do script" is implemented by supplying the argument (plus a
6338 # return character) as terminal input, there's a potential race condition
6339 # where the debugger could beat the shell to reading the command.
6340 # To prevent this, we wait for the screen to clear before proceeding.
6343 # There's no direct accessor for the tty device name, so we fiddle
6344 # with the window title options until it says what we want.
6347 # There _is_ a direct accessor for the tty device name, _and_ there's
6348 # a new possible component of the window title (the name of the settings
6349 # set). A separate version is needed.
6351 my @script_versions=
6353 ([237, <<'__LEOPARD__'],
6354 tell application "Terminal"
6355 do script "clear;exec sleep 100000"
6356 tell first tab of first window
6358 set custom title to "forked perl debugger"
6359 set title displays custom title to true
6360 repeat while (length of first paragraph of (get contents)) > 0
6368 [100, <<'__JAGUAR_TIGER__'],
6369 tell application "Terminal"
6370 do script "clear;exec sleep 100000"
6372 set title displays shell path to false
6373 set title displays window size to false
6374 set title displays file name to false
6375 set title displays device name to true
6376 set title displays custom title to true
6377 set custom title to ""
6378 copy "/dev/" & name to thetty
6379 set custom title to "forked perl debugger"
6380 repeat while (length of first paragraph of (get contents)) > 0
6390 sub macosx_get_fork_TTY
6392 my($version,$script,$pipe,$tty);
6394 return unless $version=$ENV{TERM_PROGRAM_VERSION};
6395 foreach my $entry (@script_versions) {
6396 if ($version>=$entry->[0]) {
6397 $script=$entry->[1];
6401 return unless defined($script);
6402 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
6403 $tty=readline($pipe);
6405 return unless defined($tty) && $tty =~ m(^/dev/);
6410 =head2 C<create_IN_OUT($flags)>
6412 Create a new pair of filehandles, pointing to a new TTY. If impossible,
6413 try to diagnose why.
6419 =item * 1 - Don't know how to create a new TTY.
6421 =item * 2 - Debugger has forked, but we can't get a new TTY.
6423 =item * 4 - standard debugger startup is happening.
6429 use vars qw($fork_TTY);
6431 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
6433 # If we know how to get a new TTY, do it! $in will have
6434 # the TTY name if get_fork_TTY works.
6435 my $in = &get_fork_TTY if defined &get_fork_TTY;
6437 # It used to be that
6438 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
6440 if ( not defined $in ) {
6443 # We don't know how.
6444 print_help(<<EOP) if $why == 1;
6445 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6449 print_help(<<EOP) if $why == 2;
6450 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6451 This may be an asynchronous session, so the parent debugger may be active.
6454 # Note that both debuggers are fighting over the same input.
6455 print_help(<<EOP) if $why != 4;
6456 Since two debuggers fight for the same TTY, input is severely entangled.
6460 I know how to switch the output to a different window in xterms, OS/2
6461 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
6462 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
6463 B<DB::get_fork_TTY()> returning this.
6465 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6466 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6469 } ## end if (not defined $in)
6470 elsif ( $in ne '' ) {
6474 $console = ''; # Indicate no need to open-from-the-console
6477 } ## end sub create_IN_OUT
6481 Handles rejiggering the prompt when we've forked off a new debugger.
6483 If the new debugger happened because of a C<system()> that invoked a
6484 program under the debugger, the arrow between the old pid and the new
6485 in the prompt has I<two> dashes instead of one.
6487 We take the current list of pids and add this one to the end. If there
6488 isn't any list yet, we make one up out of the initial pid associated with
6489 the terminal and our new pid, sticking an arrow (either one-dashed or
6490 two dashed) in between them.
6492 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6493 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6498 sub resetterm { # We forked, so we need a different TTY
6500 # Needs to be passed to create_IN_OUT() as well.
6503 # resetterm(2): got in here because of a system() starting a debugger.
6504 # resetterm(1): just forked.
6505 my $systemed = $in > 1 ? '-' : '';
6507 # If there's already a list of pids, add this to the end.
6509 $pids =~ s/\]/$systemed->$$]/;
6512 # No pid list. Time to make one.
6514 $pids = "[$term_pid->$$]";
6517 # The prompt we're going to be using for this debugger.
6520 # We now 0wnz this terminal.
6523 # Just return if we're not supposed to try to create a new TTY.
6524 return unless $CreateTTY & $in;
6526 # Try to create a new IN/OUT pair.
6528 } ## end sub resetterm
6532 First, we handle stuff in the typeahead buffer. If there is any, we shift off
6533 the next line, print a message saying we got it, add it to the terminal
6534 history (if possible), and return it.
6536 If there's nothing in the typeahead buffer, check the command filehandle stack.
6537 If there are any filehandles there, read from the last one, and return the line
6538 if we got one. If not, we pop the filehandle off and close it, and try the
6539 next one up the stack.
6541 If we've emptied the filehandle stack, we check to see if we've got a socket
6542 open, and we read that and return it if we do. If we don't, we just call the
6543 core C<readline()> and return its value.
6549 # Localize to prevent it from being smashed in the program being debugged.
6552 # If there are stacked filehandles to read from ...
6553 # (Handle it before the typeahead, because we may call source/etc. from
6557 # Read from the last one in the stack.
6558 my $line = CORE::readline( $cmdfhs[-1] );
6560 # If we got a line ...
6562 ? ( print $OUT ">> $line" and return $line ) # Echo and return
6563 : close pop @cmdfhs; # Pop and close
6564 } ## end while (@cmdfhs)
6566 # Pull a line out of the typeahead if there's stuff there.
6569 # How many lines left.
6570 my $left = @typeahead;
6572 # Get the next line.
6573 my $got = shift @typeahead;
6575 # Print a message saying we got input from the typeahead.
6577 print $OUT "auto(-$left)", shift, $got, "\n";
6579 # Add it to the terminal history (if possible).
6580 $term->AddHistory($got)
6582 and defined $term->Features->{addHistory};
6584 } ## end if (@typeahead)
6586 # We really need to read some input. Turn off entry/exit trace and
6587 # return value printing.
6591 # Nothing on the filehandle stack. Socket?
6592 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
6594 # Send anything we have to send.
6595 $OUT->write( join( '', @_ ) );
6597 # Receive anything there is to receive.
6602 while ($first_time or (length($buf) && ($stuff .= $buf) !~ /\n/))
6605 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
6606 # XXX Don't know. You tell me.
6611 } ## end if (ref $OUT and UNIVERSAL::isa...
6613 # No socket. Just read from the terminal.
6615 return $term->readline(@_);
6617 } ## end sub readline
6619 =head1 OPTIONS SUPPORT ROUTINES
6621 These routines handle listing and setting option values.
6623 =head2 C<dump_option> - list the current value of an option setting
6625 This routine uses C<option_val> to look up the value for an option.
6626 It cleans up escaped single-quotes and then displays the option and
6632 my ( $opt, $val ) = @_;
6633 $val = option_val( $opt, 'N/A' );
6634 $val =~ s/([\\\'])/\\$1/g;
6635 printf $OUT "%20s = '%s'\n", $opt, $val;
6636 } ## end sub dump_option
6638 sub options2remember {
6639 foreach my $k (@RememberOnROptions) {
6640 $option{$k} = option_val( $k, 'N/A' );
6645 =head2 C<option_val> - find the current value of an option
6647 This can't just be a simple hash lookup because of the indirect way that
6648 the option values are stored. Some are retrieved by calling a subroutine,
6649 some are just variables.
6651 You must supply a default value to be used in case the option isn't set.
6656 my ( $opt, $default ) = @_;
6659 # Does this option exist, and is it a variable?
6660 # If so, retrieve the value via the value in %optionVars.
6661 if ( defined $optionVars{$opt}
6662 and defined ${ $optionVars{$opt} } )
6664 $val = ${ $optionVars{$opt} };
6667 # Does this option exist, and it's a subroutine?
6668 # If so, call the subroutine via the ref in %optionAction
6669 # and capture the value.
6670 elsif ( defined $optionAction{$opt}
6671 and defined &{ $optionAction{$opt} } )
6673 $val = &{ $optionAction{$opt} }();
6676 # If there's an action or variable for the supplied option,
6677 # but no value was set, use the default.
6678 elsif (defined $optionAction{$opt} and not defined $option{$opt}
6679 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
6684 # Otherwise, do the simple hash lookup.
6686 $val = $option{$opt};
6689 # If the value isn't defined, use the default.
6690 # Then return whatever the value is.
6691 $val = $default unless defined $val;
6693 } ## end sub option_val
6695 =head2 C<parse_options>
6697 Handles the parsing and execution of option setting/displaying commands.
6699 An option entered by itself is assumed to be I<set me to 1> (the default value)
6700 if the option is a boolean one. If not, the user is prompted to enter a valid
6701 value or to query the current value (via C<option? >).
6703 If C<option=value> is entered, we try to extract a quoted string from the
6704 value (if it is quoted). If it's not, we just use the whole value as-is.
6706 We load any modules required to service this option, and then we set it: if
6707 it just gets stuck in a variable, we do that; if there's a subroutine to
6708 handle setting the option, we call that.
6710 Finally, if we're running in interactive mode, we display the effect of the
6711 user's command back to the terminal, skipping this if we're setting things
6712 during initialization.
6722 # These options need a value. Don't allow them to be clobbered by accident.
6723 my %opt_needs_val = map { ( $_ => 1 ) } qw{
6724 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
6725 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
6728 while (length($s)) {
6731 # Clean off excess leading whitespace.
6732 $s =~ s/^\s+// && next;
6734 # Options are always all word characters, followed by a non-word
6736 if ($s !~ s/^(\w+)(\W?)//) {
6737 print {$OUT} "Invalid option '$s'\n";
6740 my ( $opt, $sep ) = ( $1, $2 );
6742 # Make sure that such an option exists.
6743 my $matches = ( grep { /^\Q$opt/ && ( $option = $_ ) } @options )
6744 || ( grep { /^\Q$opt/i && ( $option = $_ ) } @options );
6747 print {$OUT} "Unknown option '$opt'\n";
6751 print {$OUT} "Ambiguous option '$opt'\n";
6756 # '?' as separator means query, but must have whitespace after it.
6757 if ( "?" eq $sep ) {
6759 print {$OUT} "Option query '$opt?' followed by non-space '$s'\n" ;
6764 #&dump_option($opt);
6765 } ## end if ("?" eq $sep)
6767 # Separator is whitespace (or just a carriage return).
6768 # They're going for a default, which we assume is 1.
6769 elsif ( $sep !~ /\S/ ) {
6771 $val = "1"; # this is an evil default; make 'em set it!
6774 # Separator is =. Trying to set a value.
6775 elsif ( $sep eq "=" ) {
6777 # If quoted, extract a quoted string.
6778 if ($s =~ s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
6780 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
6783 # Not quoted. Use the whole thing. Warn about 'option='.
6787 print OUT qq(Option better cleared using $opt=""\n)
6789 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
6791 } ## end elsif ($sep eq "=")
6793 # "Quoted" with [], <>, or {}.
6794 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
6796 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
6797 $s =~ s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
6798 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last;
6799 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
6800 } ## end else [ if ("?" eq $sep)
6802 # Exclude non-booleans from getting set to 1 by default.
6803 if ( $opt_needs_val{$option} && $val_defaulted ) {
6804 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
6806 "Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n";
6808 } ## end if ($opt_needs_val{$option...
6810 # Save the option value.
6811 $option{$option} = $val if defined $val;
6813 # Load any module that this option requires.
6814 if ( defined($optionRequire{$option}) && defined($val) ) {
6818 require '$optionRequire{$option}';
6820 } || die $@ # XXX: shouldn't happen
6824 # Stick it in the proper variable if it goes in a variable.
6825 if (defined($optionVars{$option}) && defined($val)) {
6826 ${ $optionVars{$option} } = $val;
6829 # Call the appropriate sub if it gets set via sub.
6830 if (defined($optionAction{$option})
6831 && defined (&{ $optionAction{$option} })
6834 &{ $optionAction{$option} }($val);
6837 # Not initialization - echo the value we set it to.
6838 dump_option($option) if ($OUT ne \*STDERR);
6839 } ## end while (length)
6840 } ## end sub parse_options
6842 =head1 RESTART SUPPORT
6844 These routines are used to store (and restore) lists of items in environment
6845 variables during a restart.
6849 Set_list packages up items to be stored in a set of environment variables
6850 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
6851 the values). Values outside the standard ASCII charset are stored by encoding
6852 then as hexadecimal values.
6857 my ( $stem, @list ) = @_;
6860 # VAR_n: how many we have. Scalar assignment gets the number of items.
6861 $ENV{"${stem}_n"} = @list;
6863 # Grab each item in the list, escape the backslashes, encode the non-ASCII
6864 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
6865 for my $i ( 0 .. $#list ) {
6867 $val =~ s/\\/\\\\/g;
6868 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
6869 $ENV{"${stem}_$i"} = $val;
6870 } ## end for $i (0 .. $#list)
6871 } ## end sub set_list
6875 Reverse the set_list operation: grab VAR_n to see how many we should be getting
6876 back, and then pull VAR_0, VAR_1. etc. back out.
6883 my $n = delete $ENV{"${stem}_n"};
6885 for my $i ( 0 .. $n - 1 ) {
6886 $val = delete $ENV{"${stem}_$i"};
6887 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
6891 } ## end sub get_list
6893 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
6897 The C<catch()> subroutine is the essence of fast and low-impact. We simply
6898 set an already-existing global scalar variable to a constant value. This
6899 avoids allocating any memory possibly in the middle of something that will
6900 get all confused if we do, particularly under I<unsafe signals>.
6906 return; # Put nothing on the stack - malloc/free land!
6911 C<warn> emits a warning, by joining together its arguments and printing
6912 them, with couple of fillips.
6914 If the composited message I<doesn't> end with a newline, we automatically
6915 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
6916 to be set to the filehandle to be used to output warnings; it makes no
6917 assumptions about what filehandles are available.
6922 my ($msg) = join( "", @_ );
6923 $msg .= ": $!\n" unless $msg =~ /\n$/;
6928 =head1 INITIALIZATION TTY SUPPORT
6930 =head2 C<reset_IN_OUT>
6932 This routine handles restoring the debugger's input and output filehandles
6933 after we've tried and failed to move them elsewhere. In addition, it assigns
6934 the debugger's output filehandle to $LINEINFO if it was already open there.
6939 my $switch_li = $LINEINFO eq $OUT;
6941 # If there's a term and it's able to get a new tty, try to get one.
6942 if ( $term and $term->Features->{newTTY} ) {
6943 ( $IN, $OUT ) = ( shift, shift );
6944 $term->newTTY( $IN, $OUT );
6947 # This term can't get a new tty now. Better luck later.
6949 &warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n");
6952 # Set the filehndles up as they were.
6954 ( $IN, $OUT ) = ( shift, shift );
6957 # Unbuffer the output filehandle.
6960 # Point LINEINFO to the same output filehandle if it was there before.
6961 $LINEINFO = $OUT if $switch_li;
6962 } ## end sub reset_IN_OUT
6964 =head1 OPTION SUPPORT ROUTINES
6966 The following routines are used to process some of the more complicated
6971 Sets the input and output filehandles to the specified files or pipes.
6972 If the terminal supports switching, we go ahead and do it. If not, and
6973 there's already a terminal in place, we save the information to take effect
6976 If there's no terminal yet (for instance, during debugger initialization),
6977 we go ahead and set C<$console> and C<$tty> to the file indicated.
6983 if ( @_ and $term and $term->Features->{newTTY} ) {
6985 # This terminal supports switching to a new TTY.
6986 # Can be a list of two files, or on string containing both names,
6988 # XXX Should this perhaps be an assignment from @_?
6989 my ( $in, $out ) = shift;
6992 # Split list apart if supplied.
6993 ( $in, $out ) = split /,/, $in, 2;
6997 # Use the same file for both input and output.
7001 # Open file onto the debugger's filehandles, if you can.
7002 open IN, $in or die "cannot open '$in' for read: $!";
7003 open OUT, ">$out" or die "cannot open '$out' for write: $!";
7005 # Swap to the new filehandles.
7006 reset_IN_OUT( \*IN, \*OUT );
7008 # Save the setting for later.
7010 } ## end if (@_ and $term and $term...
7012 # Terminal doesn't support new TTY, or doesn't support readline.
7013 # Can't do it now, try restarting.
7014 &warn("Too late to set TTY, enabled on next 'R'!\n") if $term and @_;
7016 # Useful if done through PERLDB_OPTS:
7017 $console = $tty = shift if @_;
7019 # Return whatever the TTY is.
7025 Sets the C<$notty> global, controlling whether or not the debugger tries to
7026 get a terminal to read from. If called after a terminal is already in place,
7027 we save the value to use it if we're restarted.
7033 &warn("Too late to set noTTY, enabled on next 'R'!\n") if @_;
7035 $notty = shift if @_;
7041 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
7042 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
7043 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
7044 the value in case a restart is done so we can change it then.
7050 &warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_;
7054 } ## end sub ReadLine
7056 =head2 C<RemotePort>
7058 Sets the port that the debugger will try to connect to when starting up.
7059 If the terminal's already been set up, we can't do it, but we remember the
7060 setting in case the user does a restart.
7066 &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
7068 $remoteport = shift if @_;
7070 } ## end sub RemotePort
7074 Checks with the terminal to see if C<Tk> is running, and returns true or
7075 false. Returns false if the current terminal doesn't support C<readline>.
7080 if ( ${ $term->Features }{tkRunning} ) {
7081 return $term->tkRunning(@_);
7085 print $OUT "tkRunning not supported by current ReadLine package.\n";
7088 } ## end sub tkRunning
7092 Sets nonstop mode. If a terminal's already been set up, it's too late; the
7093 debugger remembers the setting in case you restart, though.
7099 &warn("Too late to set up NonStop mode, enabled on next 'R'!\n")
7102 $runnonstop = shift if @_;
7104 } ## end sub NonStop
7108 &warn("Some flag changes could not take effect until next 'R'!\n")
7111 $^P = parse_DollarCaretP_flags(shift) if @_;
7112 expand_DollarCaretP_flags($^P);
7117 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
7125 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7132 Sets the shell escape command, and generates a printable copy to be used
7139 # If we got an argument, meta-quote it, and add '\b' if it
7140 # ends in a word character.
7142 $sh = quotemeta shift;
7143 $sh .= "\\b" if $sh =~ /\w$/;
7146 # Generate the printable version for the help:
7147 $psh = $sh; # copy it
7148 $psh =~ s/\\b$//; # Take off trailing \b if any
7149 $psh =~ s/\\(.)/$1/g; # De-escape
7150 $psh; # return the printable version
7151 } ## end sub shellBang
7155 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7156 was passed as the argument. (This means you can't override the terminal's
7162 if ( defined $term ) {
7164 # We don't want to show warning backtraces, but we do want die() ones.
7165 local ( $warnLevel, $dieLevel ) = ( 0, 1 );
7167 # No ornaments if the terminal doesn't support them.
7168 return '' unless $term->Features->{ornaments};
7169 eval { $term->ornaments(@_) } || '';
7172 # Use what was passed in if we can't determine it ourselves.
7176 } ## end sub ornaments
7178 =head2 C<recallCommand>
7180 Sets the recall command, and builds a printable version which will appear in
7187 # If there is input, metaquote it. Add '\b' if it ends with a word
7190 $rc = quotemeta shift;
7191 $rc .= "\\b" if $rc =~ /\w$/;
7194 # Build it into a printable version.
7195 $prc = $rc; # Copy it
7196 $prc =~ s/\\b$//; # Remove trailing \b
7197 $prc =~ s/\\(.)/$1/g; # Remove escapes
7198 $prc; # Return the printable version
7199 } ## end sub recallCommand
7201 =head2 C<LineInfo> - where the line number information goes
7203 Called with no arguments, returns the file or pipe that line info should go to.
7205 Called with an argument (a file or a pipe), it opens that onto the
7206 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7207 file or pipe again to the caller.
7215 # If this is a valid "thing to be opened for output", tack a
7216 # '>' onto the front.
7217 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7219 # If this is a pipe, the stream points to a slave editor.
7220 $slave_editor = ( $stream =~ /^\|/ );
7222 # Open it up and unbuffer it.
7223 open( LINEINFO, $stream ) || &warn("Cannot open '$stream' for write");
7224 $LINEINFO = \*LINEINFO;
7225 $LINEINFO->autoflush(1);
7229 } ## end sub LineInfo
7231 =head1 COMMAND SUPPORT ROUTINES
7233 These subroutines provide functionality for various commands.
7235 =head2 C<list_modules>
7237 For the C<M> command: list modules loaded and their versions.
7238 Essentially just runs through the keys in %INC, picks each package's
7239 C<$VERSION> variable, gets the file name, and formats the information
7244 sub list_modules { # versions
7248 # keys are the "as-loaded" name, values are the fully-qualified path
7249 # to the file itself.
7251 $file = $_; # get the module name
7252 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7253 s,/,::,g; # change '/' to '::'
7254 s/^perl5db$/DB/; # Special case: debugger
7255 # moves to package DB
7256 s/^Term::ReadLine::readline$/readline/; # simplify readline
7258 # If the package has a $VERSION package global (as all good packages
7259 # should!) decode it and save as partial message.
7260 my $pkg_version = do { no strict 'refs'; ${ $_ . '::VERSION' } };
7261 if ( defined $pkg_version ) {
7262 $version{$file} = "$pkg_version from ";
7265 # Finish up the message with the file the package came from.
7266 $version{$file} .= $INC{$file};
7267 } ## end for (keys %INC)
7269 # Hey, dumpit() formats a hash nicely, so why not use it?
7270 dumpit( $OUT, \%version );
7271 } ## end sub list_modules
7275 Sets up the monster string used to format and print the help.
7277 =head3 HELP MESSAGE FORMAT
7279 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
7280 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
7281 easy to parse and portable, but which still allows the help to be a little
7282 nicer than just plain text.
7284 Essentially, you define the command name (usually marked up with C<< B<> >>
7285 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
7286 newline. The descriptive text can also be marked up in the same way. If you
7287 need to continue the descriptive text to another line, start that line with
7288 just tabs and then enter the marked-up text.
7290 If you are modifying the help text, I<be careful>. The help-string parser is
7291 not very sophisticated, and if you don't follow these rules it will mangle the
7292 help beyond hope until you fix the string.
7296 use vars qw($pre580_help);
7297 use vars qw($pre580_summary);
7301 # XXX: make sure there are tabs between the command and explanation,
7302 # or print_help will screw up your formatting if you have
7303 # eeevil ornaments enabled. This is an insane mess.
7306 Help is currently only available for the new 5.8 command set.
7307 No help is available for the old command set.
7308 We assume you know what you're doing if you switch to it.
7311 B<s> [I<expr>] Single step [in I<expr>].
7312 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7313 <B<CR>> Repeat last B<n> or B<s> command.
7314 B<r> Return from current subroutine.
7315 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7316 at the specified position.
7317 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7318 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7319 B<l> I<line> List single I<line>.
7320 B<l> I<subname> List first window of lines from subroutine.
7321 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7322 B<l> List next window of lines.
7323 B<-> List previous window of lines.
7324 B<v> [I<line>] View window around I<line>.
7325 B<.> Return to the executed line.
7326 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7327 I<filename> may be either the full name of the file, or a regular
7328 expression matching the full file name:
7329 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7330 Evals (with saved bodies) are considered to be filenames:
7331 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7332 (in the order of execution).
7333 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7334 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7335 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
7336 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7337 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth).
7338 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
7339 B<b> Sets breakpoint on current line)
7340 B<b> [I<line>] [I<condition>]
7341 Set breakpoint; I<line> defaults to the current execution line;
7342 I<condition> breaks if it evaluates to true, defaults to '1'.
7343 B<b> I<subname> [I<condition>]
7344 Set breakpoint at first line of subroutine.
7345 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7346 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7347 B<b> B<postpone> I<subname> [I<condition>]
7348 Set breakpoint at first line of subroutine after
7350 B<b> B<compile> I<subname>
7351 Stop after the subroutine is compiled.
7352 B<B> [I<line>] Delete the breakpoint for I<line>.
7353 B<B> I<*> Delete all breakpoints.
7354 B<a> [I<line>] I<command>
7355 Set an action to be done before the I<line> is executed;
7356 I<line> defaults to the current execution line.
7357 Sequence is: check for breakpoint/watchpoint, print line
7358 if necessary, do action, prompt user if necessary,
7361 B<A> [I<line>] Delete the action for I<line>.
7362 B<A> I<*> Delete all actions.
7363 B<w> I<expr> Add a global watch-expression.
7365 B<W> I<expr> Delete a global watch-expression.
7366 B<W> I<*> Delete all watch-expressions.
7367 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7368 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7369 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7370 B<x> I<expr> Evals expression in list context, dumps the result.
7371 B<m> I<expr> Evals expression in list context, prints methods callable
7372 on the first element of the result.
7373 B<m> I<class> Prints methods callable via the given class.
7374 B<M> Show versions of loaded modules.
7375 B<i> I<class> Prints nested parents of given class.
7376 B<e> Display current thread id.
7377 B<E> Display all thread ids the current one will be identified: <n>.
7378 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7380 B<<> ? List Perl commands to run before each prompt.
7381 B<<> I<expr> Define Perl command to run before each prompt.
7382 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7383 B<< *> Delete the list of perl commands to run before each prompt.
7384 B<>> ? List Perl commands to run after each prompt.
7385 B<>> I<expr> Define Perl command to run after each prompt.
7386 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7387 B<>>B< *> Delete the list of Perl commands to run after each prompt.
7388 B<{> I<db_command> Define debugger command to run before each prompt.
7389 B<{> ? List debugger commands to run before each prompt.
7390 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7391 B<{ *> Delete the list of debugger commands to run before each prompt.
7392 B<$prc> I<number> Redo a previous command (default previous command).
7393 B<$prc> I<-number> Redo number'th-to-last command.
7394 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7395 See 'B<O> I<recallCommand>' too.
7396 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7401 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7403 See 'B<O> I<shellBang>' too.
7404 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7405 B<save> I<file> Save current debugger session (actual history) to I<file>.
7406 B<rerun> Rerun session to current position.
7407 B<rerun> I<n> Rerun session to numbered command.
7408 B<rerun> I<-n> Rerun session to number'th-to-last command.
7409 B<H> I<-number> Display last number commands (default all).
7410 B<H> I<*> Delete complete history.
7411 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7412 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7413 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well.
7414 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7415 I<command> Execute as a perl statement in current package.
7416 B<R> Pure-man-restart of debugger, some of debugger state
7417 and command-line options may be lost.
7418 Currently the following settings are preserved:
7419 history, breakpoints and actions, debugger B<O>ptions
7420 and the following command-line options: I<-w>, I<-I>, I<-e>.
7422 B<o> [I<opt>] ... Set boolean option to true
7423 B<o> [I<opt>B<?>] Query options
7424 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7425 Set options. Use quotes if spaces in value.
7426 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7427 I<pager> program for output of \"|cmd\";
7428 I<tkRunning> run Tk while prompting (with ReadLine);
7429 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7430 I<inhibit_exit> Allows stepping off the end of the script.
7431 I<ImmediateStop> Debugger should stop as early as possible.
7432 I<RemotePort> Remote hostname:port for remote debugging
7433 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7434 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7435 I<compactDump>, I<veryCompact> change style of array and hash dump;
7436 I<globPrint> whether to print contents of globs;
7437 I<DumpDBFiles> dump arrays holding debugged files;
7438 I<DumpPackages> dump symbol tables of packages;
7439 I<DumpReused> dump contents of \"reused\" addresses;
7440 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7441 I<bareStringify> Do not print the overload-stringified value;
7442 Other options include:
7443 I<PrintRet> affects printing of return value after B<r> command,
7444 I<frame> affects printing messages on subroutine entry/exit.
7445 I<AutoTrace> affects printing messages on possible breaking points.
7446 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7447 I<ornaments> affects screen appearance of the command line.
7448 I<CreateTTY> bits control attempts to create a new TTY on events:
7449 1: on fork() 2: debugger is started inside debugger
7451 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7452 You can put additional initialization options I<TTY>, I<noTTY>,
7453 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7454 B<R> after you set them).
7456 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7457 B<h> Summary of debugger commands.
7458 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7459 B<h h> Long help for debugger commands
7460 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7461 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7462 Set B<\$DB::doccmd> to change viewer.
7464 Type '|h h' for a paged display if this was too hard to read.
7466 "; # Fix balance of vi % matching: }}}}
7468 # note: tabs in the following section are not-so-helpful
7469 $summary = <<"END_SUM";
7470 I<List/search source lines:> I<Control script execution:>
7471 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7472 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7473 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7474 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7475 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7476 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7477 I<Debugger controls:> B<L> List break/watch/actions
7478 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr]
7479 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7480 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7481 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7482 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7483 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7484 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7485 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7486 B<q> or B<^D> Quit B<R> Attempt a restart
7487 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7488 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7489 B<p> I<expr> Print expression (uses script's current package).
7490 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7491 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7492 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
7493 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7494 B<e> Display thread id B<E> Display all thread ids.
7495 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7498 # ')}}; # Fix balance of vi % matching
7500 # and this is really numb...
7503 B<s> [I<expr>] Single step [in I<expr>].
7504 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7505 B<CR>> Repeat last B<n> or B<s> command.
7506 B<r> Return from current subroutine.
7507 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7508 at the specified position.
7509 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7510 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7511 B<l> I<line> List single I<line>.
7512 B<l> I<subname> List first window of lines from subroutine.
7513 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7514 B<l> List next window of lines.
7515 B<-> List previous window of lines.
7516 B<w> [I<line>] List window around I<line>.
7517 B<.> Return to the executed line.
7518 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7519 I<filename> may be either the full name of the file, or a regular
7520 expression matching the full file name:
7521 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7522 Evals (with saved bodies) are considered to be filenames:
7523 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7524 (in the order of execution).
7525 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7526 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7527 B<L> List all breakpoints and actions.
7528 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7529 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) .
7530 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
7531 B<b> [I<line>] [I<condition>]
7532 Set breakpoint; I<line> defaults to the current execution line;
7533 I<condition> breaks if it evaluates to true, defaults to '1'.
7534 B<b> I<subname> [I<condition>]
7535 Set breakpoint at first line of subroutine.
7536 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7537 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7538 B<b> B<postpone> I<subname> [I<condition>]
7539 Set breakpoint at first line of subroutine after
7541 B<b> B<compile> I<subname>
7542 Stop after the subroutine is compiled.
7543 B<d> [I<line>] Delete the breakpoint for I<line>.
7544 B<D> Delete all breakpoints.
7545 B<a> [I<line>] I<command>
7546 Set an action to be done before the I<line> is executed;
7547 I<line> defaults to the current execution line.
7548 Sequence is: check for breakpoint/watchpoint, print line
7549 if necessary, do action, prompt user if necessary,
7551 B<a> [I<line>] Delete the action for I<line>.
7552 B<A> Delete all actions.
7553 B<W> I<expr> Add a global watch-expression.
7554 B<W> Delete all watch-expressions.
7555 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7556 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7557 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7558 B<x> I<expr> Evals expression in list context, dumps the result.
7559 B<m> I<expr> Evals expression in list context, prints methods callable
7560 on the first element of the result.
7561 B<m> I<class> Prints methods callable via the given class.
7563 B<<> ? List Perl commands to run before each prompt.
7564 B<<> I<expr> Define Perl command to run before each prompt.
7565 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7566 B<>> ? List Perl commands to run after each prompt.
7567 B<>> I<expr> Define Perl command to run after each prompt.
7568 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7569 B<{> I<db_command> Define debugger command to run before each prompt.
7570 B<{> ? List debugger commands to run before each prompt.
7571 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7572 B<$prc> I<number> Redo a previous command (default previous command).
7573 B<$prc> I<-number> Redo number'th-to-last command.
7574 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7575 See 'B<O> I<recallCommand>' too.
7576 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7581 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7583 See 'B<O> I<shellBang>' too.
7584 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7585 B<H> I<-number> Display last number commands (default all).
7586 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7587 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7588 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7589 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7590 I<command> Execute as a perl statement in current package.
7591 B<v> Show versions of loaded modules.
7592 B<R> Pure-man-restart of debugger, some of debugger state
7593 and command-line options may be lost.
7594 Currently the following settings are preserved:
7595 history, breakpoints and actions, debugger B<O>ptions
7596 and the following command-line options: I<-w>, I<-I>, I<-e>.
7598 B<O> [I<opt>] ... Set boolean option to true
7599 B<O> [I<opt>B<?>] Query options
7600 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7601 Set options. Use quotes if spaces in value.
7602 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7603 I<pager> program for output of \"|cmd\";
7604 I<tkRunning> run Tk while prompting (with ReadLine);
7605 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7606 I<inhibit_exit> Allows stepping off the end of the script.
7607 I<ImmediateStop> Debugger should stop as early as possible.
7608 I<RemotePort> Remote hostname:port for remote debugging
7609 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7610 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7611 I<compactDump>, I<veryCompact> change style of array and hash dump;
7612 I<globPrint> whether to print contents of globs;
7613 I<DumpDBFiles> dump arrays holding debugged files;
7614 I<DumpPackages> dump symbol tables of packages;
7615 I<DumpReused> dump contents of \"reused\" addresses;
7616 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7617 I<bareStringify> Do not print the overload-stringified value;
7618 Other options include:
7619 I<PrintRet> affects printing of return value after B<r> command,
7620 I<frame> affects printing messages on subroutine entry/exit.
7621 I<AutoTrace> affects printing messages on possible breaking points.
7622 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7623 I<ornaments> affects screen appearance of the command line.
7624 I<CreateTTY> bits control attempts to create a new TTY on events:
7625 1: on fork() 2: debugger is started inside debugger
7627 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7628 You can put additional initialization options I<TTY>, I<noTTY>,
7629 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7630 B<R> after you set them).
7632 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7633 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7634 B<h h> Summary of debugger commands.
7635 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7636 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7637 Set B<\$DB::doccmd> to change viewer.
7639 Type '|h' for a paged display if this was too hard to read.
7641 "; # Fix balance of vi % matching: }}}}
7643 # note: tabs in the following section are not-so-helpful
7644 $pre580_summary = <<"END_SUM";
7645 I<List/search source lines:> I<Control script execution:>
7646 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7647 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7648 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
7649 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7650 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7651 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
7652 I<Debugger controls:> B<L> List break/watch/actions
7653 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7654 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7655 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
7656 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7657 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
7658 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
7659 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7660 B<q> or B<^D> Quit B<R> Attempt a restart
7661 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7662 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7663 B<p> I<expr> Print expression (uses script's current package).
7664 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7665 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7666 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
7667 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7668 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7671 # ')}}; # Fix balance of vi % matching
7673 } ## end sub sethelp
7675 =head2 C<print_help()>
7677 Most of what C<print_help> does is just text formatting. It finds the
7678 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
7679 terminal control characters to simulate them (courtesy of
7680 C<Term::ReadLine::TermCap>).
7685 my $help_str = (@_);
7687 # Restore proper alignment destroyed by eeevil I<> and B<>
7688 # ornaments: A pox on both their houses!
7690 # A help command will have everything up to and including
7691 # the first tab sequence padded into a field 16 (or if indented 20)
7692 # wide. If it's wider than that, an extra space will be added.
7694 ^ # only matters at start of line
7695 ( \040{4} | \t )* # some subcommands are indented
7696 ( < ? # so <CR> works
7697 [BI] < [^\t\n] + ) # find an eeevil ornament
7698 ( \t+ ) # original separation, discarded
7699 ( .* ) # this will now start (no earlier) than
7702 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
7703 my $clean = $command;
7704 $clean =~ s/[BI]<([^>]*)>/$1/g;
7706 # replace with this whole string:
7707 ($leadwhite ? " " x 4 : "")
7709 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
7714 $help_str =~ s{ # handle bold ornaments
7715 B < ( [^>] + | > ) >
7717 $Term::ReadLine::TermCap::rl_term_set[2]
7719 . $Term::ReadLine::TermCap::rl_term_set[3]
7722 $help_str =~ s{ # handle italic ornaments
7723 I < ( [^>] + | > ) >
7725 $Term::ReadLine::TermCap::rl_term_set[0]
7727 . $Term::ReadLine::TermCap::rl_term_set[1]
7731 print {$OUT} $help_str;
7734 } ## end sub print_help
7738 This routine does a lot of gyrations to be sure that the pager is C<less>.
7739 It checks for C<less> masquerading as C<more> and records the result in
7740 C<$fixed_less> so we don't have to go through doing the stats again.
7744 use vars qw($fixed_less);
7747 if ($pager =~ /\bless\b/)
7751 elsif ($pager =~ /\bmore\b/)
7753 # Nope, set to more. See what's out there.
7754 my @st_more = stat('/usr/bin/more');
7755 my @st_less = stat('/usr/bin/less');
7757 # is it really less, pretending to be more?
7761 && $st_more[0] == $st_less[0]
7762 && $st_more[1] == $st_less[1]
7772 # We already know if this is set.
7773 return if $fixed_less;
7775 # changes environment!
7776 # 'r' added so we don't do (slow) stats again.
7777 $fixed_less = 1 if _calc_is_less();
7780 } ## end sub fix_less
7782 =head1 DIE AND WARN MANAGEMENT
7786 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
7787 to debug a debugger problem.
7789 It does its best to report the error that occurred, and then forces the
7790 program, debugger, and everything to die.
7796 # No entry/exit messages.
7799 # No return value prints.
7802 # set the abort signal handling to the default (just terminate).
7803 $SIG{'ABRT'} = 'DEFAULT';
7805 # If we enter the signal handler recursively, kill myself with an
7806 # abort signal (so we just terminate).
7807 kill 'ABRT', $$ if $panic++;
7809 # If we can show detailed info, do so.
7810 if ( defined &Carp::longmess ) {
7812 # Don't recursively enter the warn handler, since we're carping.
7813 local $SIG{__WARN__} = '';
7815 # Skip two levels before reporting traceback: we're skipping
7816 # mydie and confess.
7817 local $Carp::CarpLevel = 2; # mydie + confess
7819 # Tell us all about it.
7820 &warn( Carp::longmess("Signal @_") );
7823 # No Carp. Tell us about the signal as best we can.
7826 print $DB::OUT "Got signal @_\n";
7831 } ## end sub diesignal
7835 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
7836 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
7842 # No entry/exit trace.
7845 # No return value printing.
7848 # Turn off warn and die handling to prevent recursive entries to this
7850 local $SIG{__WARN__} = '';
7851 local $SIG{__DIE__} = '';
7853 # Load Carp if we can. If $^S is false (current thing being compiled isn't
7854 # done yet), we may not be able to do a require.
7855 eval { require Carp }
7856 if defined $^S; # If error/warning during compilation,
7857 # require may be broken.
7859 # Use the core warn() unless Carp loaded OK.
7861 "\nCannot print stack trace, load with -MCarp option to see stack" ),
7863 unless defined &Carp::longmess;
7865 # Save the current values of $single and $trace, and then turn them off.
7866 my ( $mysingle, $mytrace ) = ( $single, $trace );
7870 # We can call Carp::longmess without its being "debugged" (which we
7871 # don't want - we just want to use it!). Capture this for later.
7872 my $mess = Carp::longmess(@_);
7874 # Restore $single and $trace to their original values.
7875 ( $single, $trace ) = ( $mysingle, $mytrace );
7877 # Use the debugger's own special way of printing warnings to print
7878 # the stack trace message.
7884 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
7885 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
7886 single stepping and tracing during the call to C<Carp::longmess> to avoid
7887 debugging it - we just want to use it.
7889 If C<dieLevel> is zero, we let the program being debugged handle the
7890 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
7891 the debugger takes over all exception handling, printing a backtrace and
7892 displaying the exception via its C<dbwarn()> routine.
7899 local $SIG{__DIE__} = '';
7900 local $SIG{__WARN__} = '';
7904 if ( $dieLevel > 2 ) {
7905 local $SIG{__WARN__} = \&dbwarn;
7906 &warn(@_); # Yell no matter what
7909 if ( $dieLevel < 2 ) {
7910 die @_ if $^S; # in eval propagate
7913 # The code used to check $^S to see if compilation of the current thing
7914 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
7915 eval { require Carp };
7918 "\nCannot print stack trace, load with -MCarp option to see stack" )
7919 unless defined &Carp::longmess;
7921 # We do not want to debug this chunk (automatic disabling works
7922 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
7923 # get the stack trace from Carp::longmess (if possible), restore $signal
7924 # and $trace, and then die with the stack trace.
7925 my ( $mysingle, $mytrace ) = ( $single, $trace );
7931 package Carp; # Do not include us in the list
7932 eval { $mess = Carp::longmess(@_); };
7934 ( $single, $trace ) = ( $mysingle, $mytrace );
7938 =head2 C<warnlevel()>
7940 Set the C<$DB::warnLevel> variable that stores the value of the
7941 C<warnLevel> option. Calling C<warnLevel()> with a positive value
7942 results in the debugger taking over all warning handlers. Setting
7943 C<warnLevel> to zero leaves any warning handlers set up by the program
7944 being debugged in place.
7950 my $prevwarn = $SIG{__WARN__} unless $warnLevel;
7953 $SIG{__WARN__} = \&DB::dbwarn;
7956 $SIG{__WARN__} = $prevwarn;
7958 undef $SIG{__WARN__};
7962 } ## end sub warnLevel
7966 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
7967 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
7968 zero lets you use your own C<die()> handler.
7975 my $prevdie = $SIG{__DIE__} unless $dieLevel;
7979 # Always set it to dbdie() for non-zero values.
7980 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
7982 # No longer exists, so don't try to use it.
7983 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
7985 # If we've finished initialization, mention that stack dumps
7986 # are enabled, If dieLevel is 1, we won't stack dump if we die
7988 print $OUT "Stack dump during die enabled",
7989 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
7992 # XXX This is probably obsolete, given that diehard() is gone.
7993 print $OUT "Dump printed too.\n" if $dieLevel > 2;
7994 } ## end if ($dieLevel)
7996 # Put the old one back if there was one.
7998 $SIG{__DIE__} = $prevdie;
7999 print $OUT "Default die handler restored.\n";
8001 undef $SIG{__DIE__};
8002 print $OUT "Die handler removed.\n";
8006 } ## end sub dieLevel
8008 =head2 C<signalLevel>
8010 Number three in a series: set C<signalLevel> to zero to keep your own
8011 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
8012 takes over and handles them with C<DB::diesignal()>.
8018 my $prevsegv = $SIG{SEGV} unless $signalLevel;
8019 my $prevbus = $SIG{BUS} unless $signalLevel;
8020 $signalLevel = shift;
8022 $SIG{SEGV} = \&DB::diesignal;
8023 $SIG{BUS} = \&DB::diesignal;
8026 $SIG{SEGV} = $prevsegv;
8027 $SIG{BUS} = $prevbus;
8031 } ## end sub signalLevel
8033 =head1 SUBROUTINE DECODING SUPPORT
8035 These subroutines are used during the C<x> and C<X> commands to try to
8036 produce as much information as possible about a code reference. They use
8037 L<Devel::Peek> to try to find the glob in which this code reference lives
8038 (if it does) - this allows us to actually code references which correspond
8039 to named subroutines (including those aliased via glob assignment).
8041 =head2 C<CvGV_name()>
8043 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
8044 via that routine. If this fails, return the reference again (when the
8045 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
8051 my $name = CvGV_name_or_bust($in);
8052 defined $name ? $name : $in;
8055 =head2 C<CvGV_name_or_bust> I<coderef>
8057 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
8058 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
8059 find a glob for this ref.
8061 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
8065 use vars qw($skipCvGV);
8067 sub CvGV_name_or_bust {
8069 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
8070 return unless ref $in;
8071 $in = \&$in; # Hard reference...
8072 eval { require Devel::Peek; 1 } or return;
8073 my $gv = Devel::Peek::CvGV($in) or return;
8074 *$gv{PACKAGE} . '::' . *$gv{NAME};
8075 } ## end sub CvGV_name_or_bust
8079 A utility routine used in various places; finds the file where a subroutine
8080 was defined, and returns that filename and a line-number range.
8082 Tries to use C<@sub> first; if it can't find it there, it tries building a
8083 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
8084 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
8085 this way, it brute-force searches C<%sub>, checking for identical references.
8089 sub _find_sub_helper {
8092 return unless defined &$subr;
8093 my $name = CvGV_name_or_bust($subr);
8095 $data = $sub{$name} if defined $name;
8096 return $data if defined $data;
8099 $subr = \&$subr; # Hard reference
8102 $s = $_, last if $subr eq \&$_;
8117 return ( $sub{$subr} || _find_sub_helper($subr) );
8118 } ## end sub find_sub
8122 A subroutine that uses the utility function C<methods_via> to find all the
8123 methods in the class corresponding to the current reference and in
8132 # Figure out the class - either this is the class or it's a reference
8133 # to something blessed into that class.
8135 $class = ref $class if ref $class;
8139 # Show the methods that this class has.
8140 methods_via( $class, '', 1 );
8142 # Show the methods that UNIVERSAL has.
8143 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
8144 } ## end sub methods
8146 =head2 C<methods_via($class, $prefix, $crawl_upward)>
8148 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
8149 all the parent class methods. C<$class> is the name of the next class to
8150 try; C<$prefix> is the message prefix, which gets built up as we go up the
8151 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
8152 higher in the C<@ISA> tree, 0 if we should stop.
8158 # If we've processed this class already, just quit.
8160 return if $seen{$class}++;
8162 # This is a package that is contributing the methods we're about to print.
8164 my $prepend = $prefix ? "via $prefix: " : '';
8167 # Extract from all the symbols in this class.
8168 my $class_ref = do { no strict "refs"; \%{$class . '::'} };
8169 while (my ($name, $glob) = each %$class_ref) {
8170 # references directly in the symbol table are Proxy Constant
8171 # Subroutines, and are by their very nature defined
8172 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8173 # to a subroutine reference, which can be tested by defined.
8174 # $glob might also be the value -1 (from sub foo;)
8175 # or (say) '$$' (from sub foo ($$);)
8176 # \$glob will be SCALAR in both cases.
8177 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8178 && !$seen{$name}++) {
8179 push @to_print, "$prepend$name\n";
8186 print $DB::OUT $_ foreach sort @to_print;
8189 # If the $crawl_upward argument is false, just quit here.
8190 return unless shift;
8192 # $crawl_upward true: keep going up the tree.
8193 # Find all the classes this one is a subclass of.
8194 my $class_ISA_ref = do { no strict "refs"; \@{"${class}::ISA"} };
8195 for my $name ( @$class_ISA_ref ) {
8197 # Set up the new prefix.
8198 $prepend = $prefix ? $prefix . " -> $name" : $name;
8200 # Crawl up the tree and keep trying to crawl up.
8201 methods_via( $name, $prepend, 1 );
8203 } ## end sub methods_via
8205 =head2 C<setman> - figure out which command to use to show documentation
8207 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8212 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|NetWare)\z/s
8213 ? "man" # O Happy Day!
8214 : "perldoc"; # Alas, poor unfortunates
8217 =head2 C<runman> - run the appropriate command to show documentation
8219 Accepts a man page name; runs the appropriate command to display it (set up
8220 during debugger initialization). Uses C<DB::system> to avoid mucking up the
8221 program's STDIN and STDOUT.
8225 my %_is_in_pods = (map { $_ => 1 }
8363 &system("$doccmd $doccmd");
8367 # this way user can override, like with $doccmd="man -Mwhatever"
8368 # or even just "man " to disable the path check.
8369 unless ( $doccmd eq 'man' ) {
8370 &system("$doccmd $page");
8374 $page = 'perl' if lc($page) eq 'help';
8377 my $man1dir = $Config::Config{'man1dir'};
8378 my $man3dir = $Config::Config{'man3dir'};
8379 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8381 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8382 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8383 chop $manpath if $manpath;
8385 # harmless if missing, I figure
8386 my $oldpath = $ENV{MANPATH};
8387 $ENV{MANPATH} = $manpath if $manpath;
8388 my $nopathopt = $^O =~ /dunno what goes here/;
8393 # I just *know* there are men without -M
8394 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8399 unless ( $page =~ /^perl\w/ ) {
8400 # do it this way because its easier to slurp in to keep up to date - clunky though.
8401 if (exists($_is_in_pods{$page})) {
8402 CORE::system( $doccmd,
8403 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8407 } ## end if (CORE::system($doccmd...
8408 if ( defined $oldpath ) {
8409 $ENV{MANPATH} = $manpath;
8412 delete $ENV{MANPATH};
8416 #use Carp; # This did break, left for debugging
8418 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
8420 Because of the way the debugger interface to the Perl core is designed, any
8421 debugger package globals that C<DB::sub()> requires have to be defined before
8422 any subroutines can be called. These are defined in the second C<BEGIN> block.
8424 This block sets things up so that (basically) the world is sane
8425 before the debugger starts executing. We set up various variables that the
8426 debugger has to have set up before the Perl core starts running:
8432 The debugger's own filehandles (copies of STD and STDOUT for now).
8436 Characters for shell escapes, the recall command, and the history command.
8440 The maximum recursion depth.
8444 The size of a C<w> command's window.
8448 The before-this-line context to be printed in a C<v> (view a window around this line) command.
8452 The fact that we're not in a sub at all right now.
8456 The default SIGINT handler for the debugger.
8460 The appropriate value of the flag in C<$^D> that says the debugger is running
8464 The current debugger recursion level
8468 The list of postponed items and the C<$single> stack (XXX define this)
8472 That we want no return values and no subroutine entry/exit trace.
8478 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
8480 use vars qw($db_stop);
8482 BEGIN { # This does not compile, alas. (XXX eh?)
8483 $IN = \*STDIN; # For bugs before DB::OUT has been opened
8484 $OUT = \*STDERR; # For errors before DB::OUT has been opened
8486 # Define characters used by command parsing.
8487 $sh = '!'; # Shell escape (does not work)
8488 $rc = ','; # Recall command (does not work)
8489 @hist = ('?'); # Show history (does not work)
8490 @truehist = (); # Can be saved for replay (per session)
8492 # This defines the point at which you get the 'deep recursion'
8493 # warning. It MUST be defined or the debugger will not load.
8496 # Number of lines around the current one that are shown in the
8500 # How much before-the-current-line context the 'v' command should
8501 # use in calculating the start of the window it will display.
8504 # We're not in any sub yet, but we need this to be a defined value.
8507 # Set up the debugger's interrupt handler. It simply sets a flag
8508 # ($signal) that DB::DB() will check before each command is executed.
8509 $SIG{INT} = \&DB::catch;
8511 # The following lines supposedly, if uncommented, allow the debugger to
8512 # debug itself. Perhaps we can try that someday.
8513 # This may be enabled to debug debugger:
8514 #$warnLevel = 1 unless defined $warnLevel;
8515 #$dieLevel = 1 unless defined $dieLevel;
8516 #$signalLevel = 1 unless defined $signalLevel;
8518 # This is the flag that says "a debugger is running, please call
8519 # DB::DB and DB::sub". We will turn it on forcibly before we try to
8520 # execute anything in the user's context, because we always want to
8522 $db_stop = 0; # Compiler warning ...
8523 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
8525 # This variable records how many levels we're nested in debugging. Used
8526 # Used in the debugger prompt, and in determining whether it's all over or
8528 $level = 0; # Level of recursive debugging
8530 # "Triggers bug (?) in perl if we postpone this until runtime."
8531 # XXX No details on this yet, or whether we should fix the bug instead
8532 # of work around it. Stay tuned.
8535 # Used to track the current stack depth using the auto-stacked-variable
8537 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
8539 # Don't print return values on exiting a subroutine.
8542 # No extry/exit tracing.
8547 BEGIN { $^W = $ini_warn; } # Switch warnings back
8549 =head1 READLINE SUPPORT - COMPLETION FUNCTION
8553 C<readline> support - adds command completion to basic C<readline>.
8555 Returns a list of possible completions to C<readline> when invoked. C<readline>
8556 will print the longest common substring following the text already entered.
8558 If there is only a single possible completion, C<readline> will use it in full.
8560 This code uses C<map> and C<grep> heavily to create lists of possible
8561 completion. Think LISP in this section.
8567 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
8568 # $text is the text to be completed.
8569 # $line is the incoming line typed by the user.
8570 # $start is the start of the text to be completed in the incoming line.
8571 my ( $text, $line, $start ) = @_;
8573 # Save the initial text.
8574 # The search pattern is current package, ::, extract the next qualifier
8575 # Prefix and pack are set to undef.
8576 my ( $itext, $search, $prefix, $pack ) =
8577 ( $text, "^\Q${package}::\E([^:]+)\$" );
8579 =head3 C<b postpone|compile>
8585 Find all the subroutines that might match in this package
8589 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
8593 Include all the rest of the subs that are known
8597 C<grep> out the ones that match the text we have so far
8601 Return this as the list of possible completions
8607 return sort grep /^\Q$text/, ( keys %sub ),
8608 qw(postpone load compile), # subroutines
8609 ( map { /$search/ ? ($1) : () } keys %sub )
8610 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
8614 Get all the possible files from C<@INC> as it currently stands and
8615 select the ones that match the text so far.
8619 return sort grep /^\Q$text/, values %INC # files
8620 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
8622 =head3 C<V> (list variable) and C<m> (list modules)
8624 There are two entry points for these commands:
8626 =head4 Unqualified package names
8628 Get the top-level packages and grab everything that matches the text
8629 so far. For each match, recursively complete the partial packages to
8630 get all possible matching packages. Return this sorted list.
8634 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8635 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
8636 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
8638 =head4 Qualified package names
8640 Take a partially-qualified package and find all subpackages for it
8641 by getting all the subpackages for the package so far, matching all
8642 the subpackages against the text, and discarding all of them which
8643 start with 'main::'. Return this list.
8647 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8648 grep !/^main::/, grep /^\Q$text/,
8649 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () }
8650 do { no strict 'refs'; keys %{ $prefix . '::' } }
8651 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
8652 and $text =~ /^(.*[^:])::?(\w*)$/
8655 =head3 C<f> - switch files
8657 Here, we want to get a fully-qualified filename for the C<f> command.
8662 =item 1. The original source file itself
8664 =item 2. A file from C<@INC>
8666 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
8672 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
8673 # We might possibly want to switch to an eval (which has a "filename"
8674 # like '(eval 9)'), so we may need to clean up the completion text
8675 # before proceeding.
8676 $prefix = length($1) - length($text);
8681 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
8682 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
8683 out of C<%main::>, add the initial source file, and extract the ones that
8684 match the completion text so far.
8689 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
8691 } ## end if ($line =~ /^\|*f\s+(.*)/)
8693 =head3 Subroutine name completion
8695 We look through all of the defined subs (the keys of C<%sub>) and
8696 return both all the possible matches to the subroutine name plus
8697 all the matches qualified to the current package.
8701 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
8702 $text = substr $text, 1;
8704 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
8706 map { /$search/ ? ($1) : () }
8709 } ## end if ((substr $text, 0, ...
8711 =head3 Scalar, array, and hash completion: partially qualified package
8713 Much like the above, except we have to do a little more cleanup:
8717 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
8725 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
8729 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
8735 Figure out the prefix vs. what needs completing.
8739 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
8746 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
8752 map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
8760 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.
8764 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8765 return db_complete( $out[0], $line, $start );
8768 # Return the list of possibles.
8771 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
8777 =head3 Symbol completion: current package or package C<main>.
8781 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
8788 If it's C<main>, delete main to just get C<::> leading.
8792 $pack = ( $package eq 'main' ? '' : $package ) . '::';
8798 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
8802 $prefix = substr $text, 0, 1;
8803 $text = substr $text, 1;
8811 We look for the lexical scope above DB::DB and auto-complete lexical variables
8812 if PadWalker could be loaded.
8816 if (not $text =~ /::/ and eval { require PadWalker } ) {
8819 my @info = caller($level);
8823 last if $info[3] eq 'DB::DB';
8826 my $lexicals = PadWalker::peek_my($level);
8827 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
8835 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
8839 push @out, map "$prefix$_", grep /^\Q$text/,
8840 ( grep /^_?[a-zA-Z]/, keys %$pack ),
8841 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
8845 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
8851 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8852 return db_complete( $out[0], $line, $start );
8855 # Return the list of possibles.
8857 } ## end if ($text =~ /^[\$@%]/)
8861 We use C<option_val()> to look up the current value of the option. If there's
8862 only a single value, we complete the command in such a way that it is a
8863 complete command for setting the option in question. If there are multiple
8864 possible values, we generate a command consisting of the option plus a trailing
8865 question mark, which, if executed, will list the current value of the option.
8869 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
8870 { # Options after space
8871 # We look for the text to be matched in the list of possible options,
8872 # and fetch the current value.
8873 my @out = grep /^\Q$text/, @options;
8874 my $val = option_val( $out[0], undef );
8876 # Set up a 'query option's value' command.
8878 if ( not defined $val or $val =~ /[\n\r]/ ) {
8880 # There's really nothing else we can do.
8883 # We have a value. Create a proper option-setting command.
8884 elsif ( $val =~ /\s/ ) {
8886 # XXX This may be an extraneous variable.
8889 # We'll want to quote the string (because of the embedded
8890 # whtespace), but we want to make sure we don't end up with
8891 # mismatched quote characters. We try several possibilities.
8892 foreach my $l ( split //, qq/\"\'\#\|/ ) {
8894 # If we didn't find this quote character in the value,
8895 # quote it using this quote character.
8896 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
8898 } ## end elsif ($val =~ /\s/)
8900 # Don't need any quotes.
8905 # If there were multiple possible values, return '? ', which
8906 # makes the command into a query command. If there was just one,
8907 # have readline append that.
8908 $rl_attribs->{completer_terminator_character} =
8909 ( @out == 1 ? $out : '? ' );
8911 # Return list of possibilities.
8913 } ## end if ((substr $line, 0, ...
8915 =head3 Filename completion
8917 For entering filenames. We simply call C<readline>'s C<filename_list()>
8918 method with the completion text to get the possible completions.
8922 return $term->filename_list($text); # filenames
8924 } ## end sub db_complete
8926 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
8928 Functions that possibly ought to be somewhere else.
8938 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n";
8943 If we have $ini_pids, save it in the environment; else remove it from the
8944 environment. Used by the C<R> (restart) command.
8949 if ( defined($ini_pids) ) {
8950 $ENV{PERLDB_PIDS} = $ini_pids;
8953 delete( $ENV{PERLDB_PIDS} );
8955 } ## end sub clean_ENV
8957 # PERLDBf_... flag names from perl.h
8958 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
8961 %DollarCaretP_flags = (
8962 PERLDBf_SUB => 0x01, # Debug sub enter/exit
8963 PERLDBf_LINE => 0x02, # Keep line #
8964 PERLDBf_NOOPT => 0x04, # Switch off optimizations
8965 PERLDBf_INTER => 0x08, # Preserve more data
8966 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
8967 PERLDBf_SINGLE => 0x20, # Start with single-step on
8968 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
8969 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
8970 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
8971 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
8972 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
8973 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
8975 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
8976 # doesn't need to set it. It's provided for the benefit of profilers and
8977 # other code analysers.
8979 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
8982 sub parse_DollarCaretP_flags {
8987 foreach my $f ( split /\s*\|\s*/, $flags ) {
8989 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
8992 elsif ( $f =~ /^(\d+)$/ ) {
8995 elsif ( $f =~ /^DEFAULT$/i ) {
8996 $value = $DollarCaretP_flags{PERLDB_ALL};
8999 $f =~ /^(?:PERLDBf_)?(.*)$/i;
9000 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
9001 unless ( defined $value ) {
9003 "Unrecognized \$^P flag '$f'!\n",
9004 "Acceptable flags are: "
9005 . join( ', ', sort keys %DollarCaretP_flags ),
9006 ", and hexadecimal and decimal numbers.\n"
9016 sub expand_DollarCaretP_flags {
9017 my $DollarCaretP = shift;
9020 my $n = ( 1 << $_ );
9021 ( $DollarCaretP & $n )
9022 ? ( $DollarCaretP_flags_r{$n}
9023 || sprintf( '0x%x', $n ) )
9027 return @bits ? join( '|', @bits ) : 0;
9034 Rerun the current session to:
9036 rerun current position
9038 rerun 4 command number 4
9040 rerun -4 current command minus 4 (go back 4 steps)
9042 Whether this always makes sense, in the current context is unknowable, and is
9043 in part left as a useful exercise for the reader. This sub returns the
9044 appropriate arguments to rerun the current session.
9051 pop(@truehist); # strim
9052 unless (defined $truehist[$i]) {
9053 print "Unable to return to non-existent command: $i\n";
9055 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
9056 my @temp = @truehist; # store
9057 push(@DB::typeahead, @truehist); # saved
9058 @truehist = @hist = (); # flush
9059 @args = &restart(); # setup
9060 &get_list("PERLDB_HIST"); # clean
9061 &set_list("PERLDB_HIST", @temp); # reset
9068 Restarting the debugger is a complex operation that occurs in several phases.
9069 First, we try to reconstruct the command line that was used to invoke Perl
9075 # I may not be able to resurrect you, but here goes ...
9077 "Warning: some settings and command-line options may be lost!\n";
9078 my ( @script, @flags, $cl );
9080 # If warn was on before, turn it on again.
9081 push @flags, '-w' if $ini_warn;
9083 # Rebuild the -I flags that were on the initial
9086 push @flags, '-I', $_;
9089 # Turn on taint if it was on before.
9090 push @flags, '-T' if ${^TAINT};
9092 # Arrange for setting the old INC:
9093 # Save the current @init_INC in the environment.
9094 set_list( "PERLDB_INC", @ini_INC );
9096 # If this was a perl one-liner, go to the "file"
9097 # corresponding to the one-liner read all the lines
9098 # out of it (except for the first one, which is going
9099 # to be added back on again when 'perl -d' runs: that's
9100 # the 'require perl5db.pl;' line), and add them back on
9101 # to the command line to be executed.
9103 my $lines = *{$main::{'_<-e'}}{ARRAY};
9104 for ( 1 .. $#$lines ) { # The first line is PERL5DB
9105 chomp( $cl = $lines->[$_] );
9106 push @script, '-e', $cl;
9108 } ## end if ($0 eq '-e')
9110 # Otherwise we just reuse the original name we had
9118 After the command line has been reconstructed, the next step is to save
9119 the debugger's status in environment variables. The C<DB::set_list> routine
9120 is used to save aggregate variables (both hashes and arrays); scalars are
9121 just popped into environment variables directly.
9125 # If the terminal supported history, grab it and
9126 # save that in the environment.
9127 set_list( "PERLDB_HIST",
9128 $term->Features->{getHistory}
9132 # Find all the files that were visited during this
9133 # session (i.e., the debugger had magic hashes
9134 # corresponding to them) and stick them in the environment.
9135 my @had_breakpoints = keys %had_breakpoints;
9136 set_list( "PERLDB_VISITED", @had_breakpoints );
9138 # Save the debugger options we chose.
9139 set_list( "PERLDB_OPT", %option );
9140 # set_list( "PERLDB_OPT", options2remember() );
9142 # Save the break-on-loads.
9143 set_list( "PERLDB_ON_LOAD", %break_on_load );
9147 The most complex part of this is the saving of all of the breakpoints. They
9148 can live in an awful lot of places, and we have to go through all of them,
9149 find the breakpoints, and then save them in the appropriate environment
9150 variable via C<DB::set_list>.
9154 # Go through all the breakpoints and make sure they're
9157 for ( 0 .. $#had_breakpoints ) {
9159 # We were in this file.
9160 my $file = $had_breakpoints[$_];
9162 # Grab that file's magic line hash.
9163 *dbline = $main::{ '_<' . $file };
9165 # Skip out if it doesn't exist, or if the breakpoint
9166 # is in a postponed file (we'll do postponed ones
9168 next unless %dbline or $postponed_file{$file};
9170 # In an eval. This is a little harder, so we'll
9171 # do more processing on that below.
9172 ( push @hard, $file ), next
9173 if $file =~ /^\(\w*eval/;
9175 # XXX I have no idea what this is doing. Yet.
9177 @add = %{ $postponed_file{$file} }
9178 if $postponed_file{$file};
9180 # Save the list of all the breakpoints for this file.
9181 set_list( "PERLDB_FILE_$_", %dbline, @add );
9183 # Serialize the extra data %breakpoints_data hash.
9185 set_list( "PERLDB_FILE_ENABLED_$_",
9186 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 }
9187 sort { $a <=> $b } keys(%dbline)
9189 } ## end for (0 .. $#had_breakpoints)
9191 # The breakpoint was inside an eval. This is a little
9192 # more difficult. XXX and I don't understand it.
9194 # Get over to the eval in question.
9195 *dbline = $main::{ '_<' . $_ };
9196 my ( $quoted, $sub, %subs, $line ) = quotemeta $_;
9197 for $sub ( keys %sub ) {
9198 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
9199 $subs{$sub} = [ $1, $2 ];
9203 "No subroutines in $_, ignoring breakpoints.\n";
9206 LINES: for $line ( keys %dbline ) {
9208 # One breakpoint per sub only:
9209 my ( $offset, $sub, $found );
9210 SUBS: for $sub ( keys %subs ) {
9213 $line # Not after the subroutine
9215 not defined $offset # Not caught
9221 $offset = $line - $subs{$sub}->[0];
9222 $offset = "+$offset", last SUBS
9224 } ## end if ($subs{$sub}->[1] >=...
9225 } ## end for $sub (keys %subs)
9226 if ( defined $offset ) {
9227 $postponed{$found} =
9228 "break $offset if $dbline{$line}";
9232 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
9234 } ## end for $line (keys %dbline)
9235 } ## end for (@hard)
9237 # Save the other things that don't need to be
9239 set_list( "PERLDB_POSTPONE", %postponed );
9240 set_list( "PERLDB_PRETYPE", @$pretype );
9241 set_list( "PERLDB_PRE", @$pre );
9242 set_list( "PERLDB_POST", @$post );
9243 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9245 # We are officially restarting.
9246 $ENV{PERLDB_RESTART} = 1;
9248 # We are junking all child debuggers.
9249 delete $ENV{PERLDB_PIDS}; # Restore ini state
9251 # Set this back to the initial pid.
9252 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9256 After all the debugger status has been saved, we take the command we built up
9257 and then return it, so we can C<exec()> it. The debugger will spot the
9258 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9259 from the environment.
9263 # And run Perl again. Add the "-d" flag, all the
9264 # flags we built up, the script (whether a one-liner
9265 # or a file), add on the -emacs flag for a slave editor,
9266 # and then the old arguments.
9268 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9274 =head1 END PROCESSING - THE C<END> BLOCK
9276 Come here at the very end of processing. We want to go into a
9277 loop where we allow the user to enter commands and interact with the
9278 debugger, but we don't want anything else to execute.
9280 First we set the C<$finished> variable, so that some commands that
9281 shouldn't be run after the end of program quit working.
9283 We then figure out whether we're truly done (as in the user entered a C<q>
9284 command, or we finished execution while running nonstop). If we aren't,
9285 we set C<$single> to 1 (causing the debugger to get control again).
9287 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9288 message and returns control to the debugger. Repeat.
9290 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9291 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9292 break, run to completion.).
9297 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9298 $fall_off_end = 1 unless $inhibit_exit;
9300 # Do not stop in at_exit() and destructors on exit:
9301 if ($fall_off_end or $runnonstop) {
9305 DB::fake::at_exit();
9309 =head1 PRE-5.8 COMMANDS
9311 Some of the commands changed function quite a bit in the 5.8 command
9312 realignment, so much so that the old code had to be replaced completely.
9313 Because we wanted to retain the option of being able to go back to the
9314 former command set, we moved the old code off to this section.
9316 There's an awful lot of duplicated code here. We've duplicated the
9317 comments to keep things clear.
9321 Does nothing. Used to I<turn off> commands.
9325 sub cmd_pre580_null {
9330 =head2 Old C<a> command.
9332 This version added actions if you supplied them, and deleted them
9341 # Argument supplied. Add the action.
9342 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9344 # If the line isn't there, use the current line.
9345 my $i = $1 || $line;
9348 # If there is an action ...
9351 # ... but the line isn't breakable, skip it.
9352 if ( $dbline[$i] == 0 ) {
9353 print $OUT "Line $i may not have an action.\n";
9357 # ... and the line is breakable:
9358 # Mark that there's an action in this file.
9359 $had_breakpoints{$filename} |= 2;
9361 # Delete any current action.
9362 $dbline{$i} =~ s/\0[^\0]*//;
9364 # Add the new action, continuing the line as needed.
9365 $dbline{$i} .= "\0" . action($j);
9367 } ## end if (length $j)
9369 # No action supplied.
9372 # Delete the action.
9373 $dbline{$i} =~ s/\0[^\0]*//;
9375 # Mark as having no break or action if nothing's left.
9376 delete $dbline{$i} if $dbline{$i} eq '';
9378 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9379 } ## end sub cmd_pre580_a
9381 =head2 Old C<b> command
9393 if ( $cmd =~ /^load\b\s*(.*)/ ) {
9399 # b compile|postpone <some sub> [<condition>]
9400 # The interpreter actually traps this one for us; we just put the
9401 # necessary condition in the %postponed hash.
9402 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
9404 # Capture the condition if there is one. Make it true if none.
9405 my $cond = length $3 ? $3 : '1';
9407 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
9408 # if it was 'compile'.
9409 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
9411 # De-Perl4-ify the name - ' separators to ::.
9412 $subname =~ s/\'/::/g;
9414 # Qualify it into the current package unless it's already qualified.
9415 $subname = "${package}::" . $subname
9416 unless $subname =~ /::/;
9418 # Add main if it starts with ::.
9419 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
9421 # Save the break type for this sub.
9422 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
9423 } ## end elsif ($cmd =~ ...
9425 # b <sub name> [<condition>]
9426 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
9428 my $cond = length $2 ? $2 : '1';
9429 &cmd_b_sub( $subname, $cond );
9431 # b <line> [<condition>].
9432 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9433 my $i = $1 || $dbline;
9434 my $cond = length $2 ? $2 : '1';
9435 &cmd_b_line( $i, $cond );
9437 } ## end sub cmd_pre580_b
9439 =head2 Old C<D> command.
9441 Delete all breakpoints unconditionally.
9448 if ( $cmd =~ /^\s*$/ ) {
9449 print $OUT "Deleting all breakpoints...\n";
9451 # %had_breakpoints lists every file that had at least one
9454 for $file ( keys %had_breakpoints ) {
9456 # Switch to the desired file temporarily.
9457 local *dbline = $main::{ '_<' . $file };
9462 # For all lines in this file ...
9463 for my $i (1 .. $max) {
9465 # If there's a breakpoint or action on this line ...
9466 if ( defined $dbline{$i} ) {
9468 # ... remove the breakpoint.
9469 $dbline{$i} =~ s/^[^\0]+//;
9470 if ( $dbline{$i} =~ s/^\0?$// ) {
9472 # Remove the entry altogether if no action is there.
9475 } ## end if (defined $dbline{$i...
9476 } ## end for my $i (1 .. $max)
9478 # If, after we turn off the "there were breakpoints in this file"
9479 # bit, the entry in %had_breakpoints for this file is zero,
9480 # we should remove this file from the hash.
9481 if ( not $had_breakpoints{$file} &= ~1 ) {
9482 delete $had_breakpoints{$file};
9484 } ## end for $file (keys %had_breakpoints)
9486 # Kill off all the other breakpoints that are waiting for files that
9487 # haven't been loaded yet.
9489 undef %postponed_file;
9490 undef %break_on_load;
9491 } ## end if ($cmd =~ /^\s*$/)
9492 } ## end sub cmd_pre580_D
9494 =head2 Old C<h> command
9496 Print help. Defaults to printing the long-form help; the 5.8 version
9497 prints the summary by default.
9505 # Print the *right* help, long format.
9506 if ( $cmd =~ /^\s*$/ ) {
9507 print_help($pre580_help);
9510 # 'h h' - explicitly-requested summary.
9511 elsif ( $cmd =~ /^h\s*/ ) {
9512 print_help($pre580_summary);
9515 # Find and print a command's help.
9516 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
9517 my $asked = $1; # for proper errmsg
9518 my $qasked = quotemeta($asked); # for searching
9519 # XXX: finds CR but not <CR>
9523 (?:[IB]<) # Optional markup
9524 $qasked # The command name
9531 ( # The command help:
9533 (?:[IB]<) # Optional markup
9534 $qasked # The command name
9535 ([\s\S]*?) # Lines starting with tabs
9539 ) # Line not starting with space
9540 # (Next command's help)
9544 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
9548 print_help("B<$asked> is not a debugger command.\n");
9550 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
9551 } ## end sub cmd_pre580_h
9553 =head2 Old C<W> command
9555 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
9563 # Delete all watch expressions.
9564 if ( $cmd =~ /^$/ ) {
9566 # No watching is going on.
9569 # Kill all the watch expressions and values.
9570 @to_watch = @old_watch = ();
9573 # Add a watch expression.
9574 elsif ( $cmd =~ /^(.*)/s ) {
9576 # add it to the list to be watched.
9579 # Get the current value of the expression.
9580 # Doesn't handle expressions returning list values!
9583 $val = ( defined $val ) ? "'$val'" : 'undef';
9586 push @old_watch, $val;
9588 # We're watching stuff.
9591 } ## end elsif ($cmd =~ /^(.*)/s)
9592 } ## end sub cmd_pre580_W
9594 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
9596 The debugger used to have a bunch of nearly-identical code to handle
9597 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
9598 C<cmd_prepost> unify all this into one set of code to handle the
9599 appropriate actions.
9601 =head2 C<cmd_pre590_prepost>
9603 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
9604 do something destructive. In pre 5.8 debuggers, the default action was to
9605 delete all the actions.
9609 sub cmd_pre590_prepost {
9611 my $line = shift || '*';
9614 return &cmd_prepost( $cmd, $line, $dbline );
9615 } ## end sub cmd_pre590_prepost
9617 =head2 C<cmd_prepost>
9619 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
9620 Since the lists of actions are all held in arrays that are pointed to by
9621 references anyway, all we have to do is pick the right array reference and
9622 then use generic code to all, delete, or list actions.
9629 # No action supplied defaults to 'list'.
9630 my $line = shift || '?';
9632 # Figure out what to put in the prompt.
9635 # Make sure we have some array or another to address later.
9636 # This means that if ssome reason the tests fail, we won't be
9637 # trying to stash actions or delete them from the wrong place.
9640 # < - Perl code to run before prompt.
9641 if ( $cmd =~ /^\</o ) {
9642 $which = 'pre-perl';
9646 # > - Perl code to run after prompt.
9647 elsif ( $cmd =~ /^\>/o ) {
9648 $which = 'post-perl';
9652 # { - first check for properly-balanced braces.
9653 elsif ( $cmd =~ /^\{/o ) {
9654 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
9656 "$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n";
9659 # Properly balanced. Pre-prompt debugger actions.
9661 $which = 'pre-debugger';
9664 } ## end elsif ( $cmd =~ /^\{/o )
9666 # Did we find something that makes sense?
9668 print $OUT "Confused by command: $cmd\n";
9675 if ( $line =~ /^\s*\?\s*$/o ) {
9678 # Nothing there. Complain.
9679 print $OUT "No $which actions.\n";
9683 # List the actions in the selected list.
9684 print $OUT "$which commands:\n";
9685 foreach my $action (@$aref) {
9686 print $OUT "\t$cmd -- $action\n";
9689 } ## end if ( $line =~ /^\s*\?\s*$/o)
9691 # Might be a delete.
9693 if ( length($cmd) == 1 ) {
9694 if ( $line =~ /^\s*\*\s*$/o ) {
9696 # It's a delete. Get rid of the old actions in the
9699 print $OUT "All $cmd actions cleared.\n";
9703 # Replace all the actions. (This is a <, >, or {).
9704 @$aref = action($line);
9706 } ## end if ( length($cmd) == 1)
9707 elsif ( length($cmd) == 2 ) {
9709 # Add the action to the line. (This is a <<, >>, or {{).
9710 push @$aref, action($line);
9714 # <<<, >>>>, {{{{{{ ... something not a command.
9716 "Confused by strange length of $which command($cmd)...\n";
9718 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
9720 } ## end sub cmd_prepost
9724 Contains the C<at_exit> routine that the debugger uses to issue the
9725 C<Debugged program terminated ...> message after the program completes. See
9726 the C<END> block documentation for more details.
9733 "Debugged program terminated. Use 'q' to quit or 'R' to restart.";
9736 package DB; # Do not trace this 1; below!