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<$filename>
275 is the expanded name of the C<require>d file (as found via C<%INC>).
277 =head3 IMPORTANT INTERNAL VARIABLES
281 Used to control when the debugger will attempt to acquire another TTY to be
286 =item * 1 - on C<fork()>
288 =item * 2 - debugger is started inside debugger
290 =item * 4 - on startup
296 The value -2 indicates that no return value should be printed.
297 Any other positive value causes C<DB::sub> to print return values.
301 The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
302 contents of C<@_> when C<DB::eval> is called.
306 Determines what messages (if any) will get printed when a subroutine (or eval)
307 is entered or exited.
311 =item * 0 - No enter/exit messages
313 =item * 1 - Print I<entering> messages on subroutine entry
315 =item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
317 =item * 4 - Extended messages: C<< <in|out> I<context>=I<fully-qualified sub name> from I<file>:I<line> >>. If no other flag is on, acts like 1+4.
319 =item * 8 - Adds parameter information to messages, and overloaded stringify and tied FETCH is enabled on the printed arguments. Ignored if C<4> is not on.
321 =item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is not on.
325 To get everything, use C<$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
519 BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
523 $^V =~ /^v(\d+\.\d+)/;
524 feature->import(":$1");
525 $_initial_cwd = Cwd::getcwd();
528 # Debugger for Perl 5.00x; perl5db.pl patch level:
529 use vars qw($VERSION $header);
531 # bump to X.XX in blead, only use X.XX_XX in maint
534 $header = "perl5db.pl version $VERSION";
536 =head1 DEBUGGER ROUTINES
540 This function replaces straight C<eval()> inside the debugger; it simplifies
541 the process of evaluating code in the user's context.
543 The code to be evaluated is passed via the package global variable
544 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
546 Before we do the C<eval()>, we preserve the current settings of C<$trace>,
547 C<$single>, C<$^D> and C<$usercontext>. The latter contains the
548 preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
549 user's current package, grabbed when C<DB::DB> got control. This causes the
550 proper context to be used when the eval is actually done. Afterward, we
551 restore C<$trace>, C<$single>, and C<$^D>.
553 Next we need to handle C<$@> without getting confused. We save C<$@> in a
554 local lexical, localize C<$saved[0]> (which is where C<save()> will put
555 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
556 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
557 considered sane by the debugger. If there was an C<eval()> error, we print
558 it on the debugger's output. If C<$onetimedump> is defined, we call
559 C<dumpit> if it's set to 'dump', or C<methods> if it's set to
560 'methods'. Setting it to something else causes the debugger to do the eval
561 but not print the result - handy if you want to do something else with it
562 (the "watch expressions" code does this to get the value of the watch
563 expression but not show it unless it matters).
565 In any case, we then return the list of output from C<eval> to the caller,
566 and unwinding restores the former version of C<$@> in C<@saved> as well
567 (the localization of C<$saved[0]> goes away at the end of this scope).
569 =head3 Parameters and variables influencing execution of DB::eval()
571 C<DB::eval> isn't parameterized in the standard way; this is to keep the
572 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
573 The variables listed below influence C<DB::eval()>'s execution directly.
577 =item C<$evalarg> - the thing to actually be eval'ed
579 =item C<$trace> - Current state of execution tracing
581 =item C<$single> - Current state of single-stepping
583 =item C<$onetimeDump> - what is to be displayed after the evaluation
585 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
589 The following variables are altered by C<DB::eval()> during its execution. They
590 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
594 =item C<@res> - used to capture output from actual C<eval>.
596 =item C<$otrace> - saved value of C<$trace>.
598 =item C<$osingle> - saved value of C<$single>.
600 =item C<$od> - saved value of C<$^D>.
602 =item C<$saved[0]> - saved value of C<$@>.
604 =item $\ - for output of C<$@> if there is an evaluation error.
608 =head3 The problem of lexicals
610 The context of C<DB::eval()> presents us with some problems. Obviously,
611 we want to be 'sandboxed' away from the debugger's internals when we do
612 the eval, but we need some way to control how punctuation variables and
613 debugger globals are used.
615 We can't use local, because the code inside C<DB::eval> can see localized
616 variables; and we can't use C<my> either for the same reason. The code
617 in this routine compromises and uses C<my>.
619 After this routine is over, we don't have user code executing in the debugger's
620 context, so we can use C<my> freely.
624 ############################################## Begin lexical danger zone
626 # 'my' variables used here could leak into (that is, be visible in)
627 # the context that the code being evaluated is executing in. This means that
628 # the code could modify the debugger's variables.
630 # Fiddling with the debugger's context could be Bad. We insulate things as
695 # Used to save @ARGV and extract any debugger-related flags.
698 # Used to prevent multiple entries to diesignal()
699 # (if for instance diesignal() itself dies)
702 # Used to prevent the debugger from running nonstop
706 sub _calc_usercontext {
709 # Cancel strict completely for the evaluated code, so the code
710 # the user evaluates won't be affected by it. (Shlomi Fish)
711 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
712 . "package $package;"; # this won't let them modify, alas
717 # 'my' would make it visible from user code
718 # but so does local! --tchrist
719 # Remember: this localizes @DB::res, not @main::res.
723 # Try to keep the user code from messing with us. Save these so that
724 # even if the eval'ed code changes them, we can put them back again.
725 # Needed because the user could refer directly to the debugger's
726 # package globals (and any 'my' variables in this containing scope)
727 # inside the eval(), and we want to try to stay safe.
728 local $otrace = $trace;
729 local $osingle = $single;
732 # Untaint the incoming eval() argument.
733 { ($evalarg) = $evalarg =~ /(.*)/s; }
735 # $usercontext built in DB::DB near the comment
736 # "set up the context for DB::eval ..."
737 # Evaluate and save any results.
738 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
740 # Restore those old values.
746 # Save the current value of $@, and preserve it in the debugger's copy
747 # of the saved precious globals.
750 # Since we're only saving $@, we only have to localize the array element
751 # that it will be stored in.
752 local $saved[0]; # Preserve the old value of $@
755 # Now see whether we need to report an error back to the user.
761 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
762 # are package globals.
763 elsif ($onetimeDump) {
764 if ( $onetimeDump eq 'dump' ) {
765 local $option{dumpDepth} = $onetimedumpDepth
766 if defined $onetimedumpDepth;
767 dumpit( $OUT, \@res );
769 elsif ( $onetimeDump eq 'methods' ) {
772 } ## end elsif ($onetimeDump)
776 ############################################## End lexical danger zone
778 # After this point it is safe to introduce lexicals.
779 # The code being debugged will be executing in its own context, and
780 # can't see the inside of the debugger.
782 # However, one should not overdo it: leave as much control from outside as
783 # possible. If you make something a lexical, it's not going to be addressable
784 # from outside the debugger even if you know its name.
786 # This file is automatically included if you do perl -d.
787 # It's probably not useful to include this yourself.
789 # Before venturing further into these twisty passages, it is
790 # wise to read the perldebguts man page or risk the ire of dragons.
792 # (It should be noted that perldebguts will tell you a lot about
793 # the underlying mechanics of how the debugger interfaces into the
794 # Perl interpreter, but not a lot about the debugger itself. The new
795 # comments in this code try to address this problem.)
797 # Note that no subroutine call is possible until &DB::sub is defined
798 # (for subroutines defined outside of the package DB). In fact the same is
799 # true if $deep is not defined.
801 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
803 # modified Perl debugger, to be run from Emacs in perldb-mode
804 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
805 # Johan Vromans -- upgrade to 4.0 pl 10
806 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
807 ########################################################################
809 =head1 DEBUGGER INITIALIZATION
811 The debugger starts up in phases.
815 First, it initializes the environment it wants to run in: turning off
816 warnings during its own compilation, defining variables which it will need
817 to avoid warnings later, setting itself up to not exit when the program
818 terminates, and defaulting to printing return values for the C<r> command.
822 # Needed for the statement after exec():
824 # This BEGIN block is simply used to switch off warnings during debugger
825 # compilation. Probably it would be better practice to fix the warnings,
826 # but this is how it's done at the moment.
831 } # Switch compilation warnings off until another BEGIN.
833 local ($^W) = 0; # Switch run-time warnings off during init.
835 =head2 THREADS SUPPORT
837 If we are running under a threaded Perl, we require threads and threads::shared
838 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
839 threaded debugger control. C<-dt> can also be used to set this.
841 Each new thread will be announced and the debugger prompt will always inform
842 you of each new thread created. It will also indicate the thread id in which
843 we are currently running within the prompt like this:
847 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
848 command prompt. The prompt will show: C<[0]> when running under threads, but
849 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
851 While running under threads, when you set or delete a breakpoint (etc.), this
852 will apply to all threads, not just the currently running one. When you are
853 in a currently executing thread, you will stay there until it completes. With
854 the current implementation it is not currently possible to hop from one thread
857 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
859 Note that threading support was built into the debugger as of Perl version
860 C<5.8.6> and debugger version C<1.2.8>.
865 # ensure we can share our non-threaded variables or no-op
866 if ($ENV{PERL5DB_THREADED}) {
868 require threads::shared;
869 import threads::shared qw(share);
873 print "Threads support enabled\n";
876 *share = sub(\[$@%]) {};
880 # These variables control the execution of 'dumpvar.pl'.
895 # used to control die() reporting in diesignal()
898 use vars qw($CarpLevel);
901 # without threads, $filename is not defined until DB::DB is called
902 share($main::{'_<'.$filename}) if defined $filename;
904 # Command-line + PERLLIB:
905 # Save the contents of @INC before they are modified elsewhere.
908 # This was an attempt to clear out the previous values of various
909 # trapped errors. Apparently it didn't help. XXX More info needed!
910 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
912 # We set these variables to safe values. We don't want to blindly turn
913 # off warnings, because other packages may still want them.
914 $trace = $signal = $single = 0; # Uninitialized warning suppression
915 # (local $^W cannot help - other packages!).
917 # Default to not exiting when program finishes; print the return
918 # value when the 'r' command is used to return from a subroutine.
919 $inhibit_exit = $option{PrintRet} = 1;
921 use vars qw($trace_to_depth);
923 # Default to 1E9 so it won't be limited to a certain recursion depth.
924 $trace_to_depth = 1E9;
926 =head1 OPTION PROCESSING
928 The debugger's options are actually spread out over the debugger itself and
929 C<dumpvar.pl>; some of these are variables to be set, while others are
930 subs to be called with a value. To try to make this a little easier to
931 manage, the debugger uses a few data structures to define what options
932 are legal and how they are to be processed.
934 First, the C<@options> array defines the I<names> of all the options that
940 CommandSet HistFile HistSize
941 hashDepth arrayDepth dumpDepth
942 DumpDBFiles DumpPackages DumpReused
943 compactDump veryCompact quote
944 HighBit undefPrint globPrint
945 PrintRet UsageOnly frame
947 ReadLine NonStop LineInfo
948 maxTraceLen recallCommand ShellBang
949 pager tkRunning ornaments
950 signalLevel warnLevel dieLevel
951 inhibit_exit ImmediateStop bareStringify
952 CreateTTY RemotePort windowSize
956 @RememberOnROptions = qw(DollarCaretP);
960 Second, C<optionVars> lists the variables that each option uses to save its
965 use vars qw(%optionVars);
968 hashDepth => \$dumpvar::hashDepth,
969 arrayDepth => \$dumpvar::arrayDepth,
970 CommandSet => \$CommandSet,
971 DumpDBFiles => \$dumpvar::dumpDBFiles,
972 DumpPackages => \$dumpvar::dumpPackages,
973 DumpReused => \$dumpvar::dumpReused,
974 HighBit => \$dumpvar::quoteHighBit,
975 undefPrint => \$dumpvar::printUndef,
976 globPrint => \$dumpvar::globPrint,
977 UsageOnly => \$dumpvar::usageOnly,
978 CreateTTY => \$CreateTTY,
979 bareStringify => \$dumpvar::bareStringify,
981 AutoTrace => \$trace,
982 inhibit_exit => \$inhibit_exit,
983 maxTraceLen => \$maxtrace,
984 ImmediateStop => \$ImmediateStop,
985 RemotePort => \$remoteport,
986 windowSize => \$window,
987 HistFile => \$histfile,
988 HistSize => \$histsize,
993 Third, C<%optionAction> defines the subroutine to be called to process each
998 use vars qw(%optionAction);
1001 compactDump => \&dumpvar::compactDump,
1002 veryCompact => \&dumpvar::veryCompact,
1003 quote => \&dumpvar::quote,
1006 ReadLine => \&ReadLine,
1007 NonStop => \&NonStop,
1008 LineInfo => \&LineInfo,
1009 recallCommand => \&recallCommand,
1010 ShellBang => \&shellBang,
1012 signalLevel => \&signalLevel,
1013 warnLevel => \&warnLevel,
1014 dieLevel => \&dieLevel,
1015 tkRunning => \&tkRunning,
1016 ornaments => \&ornaments,
1017 RemotePort => \&RemotePort,
1018 DollarCaretP => \&DollarCaretP,
1023 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1028 # Note that this list is not complete: several options not listed here
1029 # actually require that dumpvar.pl be loaded for them to work, but are
1030 # not in the table. A subsequent patch will correct this problem; for
1031 # the moment, we're just recommenting, and we are NOT going to change
1033 use vars qw(%optionRequire);
1036 compactDump => 'dumpvar.pl',
1037 veryCompact => 'dumpvar.pl',
1038 quote => 'dumpvar.pl',
1043 There are a number of initialization-related variables which can be set
1044 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1045 variable. These are:
1049 =item C<$rl> - readline control XXX needs more explanation
1051 =item C<$warnLevel> - whether or not debugger takes over warning handling
1053 =item C<$dieLevel> - whether or not debugger takes over die handling
1055 =item C<$signalLevel> - whether or not debugger takes over signal handling
1057 =item C<$pre> - preprompt actions (array reference)
1059 =item C<$post> - postprompt actions (array reference)
1063 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1065 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1071 # These guys may be defined in $ENV{PERL5DB} :
1072 $rl = 1 unless defined $rl;
1073 $warnLevel = 1 unless defined $warnLevel;
1074 $dieLevel = 1 unless defined $dieLevel;
1075 $signalLevel = 1 unless defined $signalLevel;
1076 $pre = [] unless defined $pre;
1077 $post = [] unless defined $post;
1078 $pretype = [] unless defined $pretype;
1079 $CreateTTY = 3 unless defined $CreateTTY;
1080 $CommandSet = '580' unless defined $CommandSet;
1085 share($signalLevel);
1095 The default C<die>, C<warn>, and C<signal> handlers are set up.
1099 warnLevel($warnLevel);
1100 dieLevel($dieLevel);
1101 signalLevel($signalLevel);
1105 The pager to be used is needed next. We try to get it from the
1106 environment first. If it's not defined there, we try to find it in
1107 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1108 then call the C<pager()> function to save the pager name.
1112 # This routine makes sure $pager is set up so that '|' can use it.
1115 # If PAGER is defined in the environment, use it.
1119 # If not, see if Config.pm defines it.
1120 : eval { require Config }
1121 && defined $Config::Config{pager}
1122 ? $Config::Config{pager}
1124 # If not, fall back to 'more'.
1127 unless defined $pager;
1131 We set up the command to be used to access the man pages, the command
1132 recall character (C<!> unless otherwise defined) and the shell escape
1133 character (C<!> unless otherwise defined). Yes, these do conflict, and
1134 neither works in the debugger at the moment.
1140 # Set up defaults for command recall and shell escape (note:
1141 # these currently don't work in linemode debugging).
1142 recallCommand("!") unless defined $prc;
1143 shellBang("!") unless defined $psh;
1147 We then set up the gigantic string containing the debugger help.
1148 We also set the limit on the number of arguments we'll display during a
1155 # If we didn't get a default for the length of eval/stack trace args,
1157 $maxtrace = 400 unless defined $maxtrace;
1159 =head2 SETTING UP THE DEBUGGER GREETING
1161 The debugger I<greeting> helps to inform the user how many debuggers are
1162 running, and whether the current debugger is the primary or a child.
1164 If we are the primary, we just hang onto our pid so we'll have it when
1165 or if we start a child debugger. If we are a child, we'll set things up
1166 so we'll have a unique greeting and so the parent will give us our own
1169 We save the current contents of the C<PERLDB_PIDS> environment variable
1170 because we mess around with it. We'll also need to hang onto it because
1171 we'll need it if we restart.
1173 Child debuggers make a label out of the current PID structure recorded in
1174 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1175 yet so the parent will give them one later via C<resetterm()>.
1179 # Save the current contents of the environment; we're about to
1180 # much with it. We'll need this if we have to restart.
1181 use vars qw($ini_pids);
1182 $ini_pids = $ENV{PERLDB_PIDS};
1184 use vars qw ($pids $term_pid);
1186 if ( defined $ENV{PERLDB_PIDS} ) {
1188 # We're a child. Make us a label out of the current PID structure
1189 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1190 # a term yet so the parent will give us one later via resetterm().
1192 my $env_pids = $ENV{PERLDB_PIDS};
1193 $pids = "[$env_pids]";
1195 # Unless we are on OpenVMS, all programs under the DCL shell run under
1198 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1202 $ENV{PERLDB_PIDS} .= "->$$";
1206 } ## end if (defined $ENV{PERLDB_PIDS...
1209 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1210 # child debugger, and mark us as the parent, so we'll know to set up
1211 # more TTY's is we have to.
1212 $ENV{PERLDB_PIDS} = "$$";
1217 use vars qw($pidprompt);
1220 # Sets up $emacs as a synonym for $slave_editor.
1221 our ($slave_editor);
1222 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1224 =head2 READING THE RC FILE
1226 The debugger will read a file of initialization options if supplied. If
1227 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1231 # As noted, this test really doesn't check accurately that the debugger
1232 # is running at a terminal or not.
1234 use vars qw($rcfile);
1236 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1237 # this is the wrong metric!
1238 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
1243 The debugger does a safety test of the file to be read. It must be owned
1244 either by the current user or root, and must only be writable by the owner.
1248 # This wraps a safety test around "do" to read and evaluate the init file.
1250 # This isn't really safe, because there's a race
1251 # between checking and opening. The solution is to
1252 # open and fstat the handle, but then you have to read and
1253 # eval the contents. But then the silly thing gets
1254 # your lexical scope, which is unfortunate at best.
1258 # Just exactly what part of the word "CORE::" don't you understand?
1259 local $SIG{__WARN__};
1260 local $SIG{__DIE__};
1262 unless ( is_safe_file($file) ) {
1263 CORE::warn <<EO_GRIPE;
1264 perldb: Must not source insecure rcfile $file.
1265 You or the superuser must be the owner, and it must not
1266 be writable by anyone but its owner.
1269 } ## end unless (is_safe_file($file...
1272 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1273 } ## end sub safe_do
1275 # This is the safety test itself.
1277 # Verifies that owner is either real user or superuser and that no
1278 # one but owner may write to it. This function is of limited use
1279 # when called on a path instead of upon a handle, because there are
1280 # no guarantees that filename (by dirent) whose file (by ino) is
1281 # eventually accessed is the same as the one tested.
1282 # Assumes that the file's existence is not in doubt.
1285 stat($path) || return; # mysteriously vaporized
1286 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1288 return 0 if $uid != 0 && $uid != $<;
1289 return 0 if $mode & 022;
1291 } ## end sub is_safe_file
1293 # If the rcfile (whichever one we decided was the right one to read)
1294 # exists, we safely do it.
1296 safe_do("./$rcfile");
1299 # If there isn't one here, try the user's home directory.
1300 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1301 safe_do("$ENV{HOME}/$rcfile");
1304 # Else try the login directory.
1305 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1306 safe_do("$ENV{LOGDIR}/$rcfile");
1309 # If the PERLDB_OPTS variable has options in it, parse those out next.
1310 if ( defined $ENV{PERLDB_OPTS} ) {
1311 parse_options( $ENV{PERLDB_OPTS} );
1316 The last thing we do during initialization is determine which subroutine is
1317 to be used to obtain a new terminal when a new debugger is started. Right now,
1318 the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
1323 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1324 # Works if you're running an xterm or xterm-like window, or you're on
1325 # OS/2, or on Mac OS X. This may need some expansion.
1327 if (not defined &get_fork_TTY) # only if no routine exists
1329 if ( defined $remoteport ) {
1330 # Expect an inetd-like server
1331 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1333 elsif (defined $ENV{TERM} # If we know what kind
1334 # of terminal this is,
1335 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1336 and defined $ENV{DISPLAY} # and what display it's on,
1339 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1341 elsif ( $ENV{TMUX} ) {
1342 *get_fork_TTY = \&tmux_get_fork_TTY;
1344 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1345 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1347 elsif ( $^O eq 'darwin' # If this is Mac OS X
1348 and defined $ENV{TERM_PROGRAM} # and we're running inside
1349 and $ENV{TERM_PROGRAM}
1350 eq 'Apple_Terminal' # Terminal.app
1353 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1355 } ## end if (not defined &get_fork_TTY...
1357 # untaint $^O, which may have been tainted by the last statement.
1358 # see bug [perl #24674]
1362 # Here begin the unreadable code. It needs fixing.
1364 =head2 RESTART PROCESSING
1366 This section handles the restart command. When the C<R> command is invoked, it
1367 tries to capture all of the state it can into environment variables, and
1368 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1369 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1370 the R command stuffed into the environment variables.
1372 PERLDB_RESTART - flag only, contains no restart data itself.
1373 PERLDB_HIST - command history, if it's available
1374 PERLDB_ON_LOAD - breakpoints set by the rc file
1375 PERLDB_POSTPONE - subs that have been loaded/not executed,
1377 PERLDB_VISITED - files that had breakpoints
1378 PERLDB_FILE_... - breakpoints for a file
1379 PERLDB_OPT - active options
1380 PERLDB_INC - the original @INC
1381 PERLDB_PRETYPE - preprompt debugger actions
1382 PERLDB_PRE - preprompt Perl code
1383 PERLDB_POST - post-prompt Perl code
1384 PERLDB_TYPEAHEAD - typeahead captured by readline()
1386 We chug through all these variables and plug the values saved in them
1387 back into the appropriate spots in the debugger.
1391 use vars qw(%postponed_file @typeahead);
1393 our (@hist, @truehist);
1395 sub _restore_shared_globals_after_restart
1397 @hist = get_list('PERLDB_HIST');
1398 %break_on_load = get_list("PERLDB_ON_LOAD");
1399 %postponed = get_list("PERLDB_POSTPONE");
1403 share(%break_on_load);
1407 sub _restore_breakpoints_and_actions {
1409 my @had_breakpoints = get_list("PERLDB_VISITED");
1411 for my $file_idx ( 0 .. $#had_breakpoints ) {
1412 my $filename = $had_breakpoints[$file_idx];
1413 my %pf = get_list("PERLDB_FILE_$file_idx");
1414 $postponed_file{ $filename } = \%pf if %pf;
1415 my @lines = sort {$a <=> $b} keys(%pf);
1416 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1417 for my $line_idx (0 .. $#lines) {
1418 _set_breakpoint_enabled_status(
1421 ($enabled_statuses[$line_idx] ? 1 : ''),
1429 sub _restore_options_after_restart
1431 my %options_map = get_list("PERLDB_OPT");
1433 while ( my ( $opt, $val ) = each %options_map ) {
1434 $val =~ s/[\\\']/\\$1/g;
1435 parse_options("$opt'$val'");
1441 sub _restore_globals_after_restart
1443 # restore original @INC
1444 @INC = get_list("PERLDB_INC");
1447 # return pre/postprompt actions and typeahead buffer
1448 $pretype = [ get_list("PERLDB_PRETYPE") ];
1449 $pre = [ get_list("PERLDB_PRE") ];
1450 $post = [ get_list("PERLDB_POST") ];
1451 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1457 if ( exists $ENV{PERLDB_RESTART} ) {
1459 # We're restarting, so we don't need the flag that says to restart anymore.
1460 delete $ENV{PERLDB_RESTART};
1463 _restore_shared_globals_after_restart();
1465 _restore_breakpoints_and_actions();
1468 _restore_options_after_restart();
1470 _restore_globals_after_restart();
1471 } ## end if (exists $ENV{PERLDB_RESTART...
1473 =head2 SETTING UP THE TERMINAL
1475 Now, we'll decide how the debugger is going to interact with the user.
1476 If there's no TTY, we set the debugger to run non-stop; there's not going
1477 to be anyone there to enter commands.
1481 use vars qw($notty $console $tty $LINEINFO);
1482 use vars qw($lineinfo $doccmd);
1486 # Local autoflush to avoid rt#116769,
1487 # as calling IO::File methods causes an unresolvable loop
1488 # that results in debugger failure.
1490 my $o = select($_[0]);
1502 If there is a TTY, we have to determine who it belongs to before we can
1503 proceed. If this is a slave editor or graphical debugger (denoted by
1504 the first command-line switch being '-emacs'), we shift this off and
1505 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1511 # Is Perl being run from a slave editor or graphical debugger?
1512 # If so, don't use readline, and set $slave_editor = 1.
1513 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1518 #require Term::ReadLine;
1522 We then determine what the console should be on various systems:
1526 =item * Cygwin - We use C<stdin> instead of a separate device.
1530 if ( $^O eq 'cygwin' ) {
1532 # /dev/tty is binary. use stdin for textmode
1536 =item * Windows or MSDOS - use C<con>.
1540 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1544 =item * AmigaOS - use C<CONSOLE:>.
1548 elsif ( $^O eq 'amigaos' ) {
1549 $console = "CONSOLE:";
1552 =item * VMS - use C<sys$command>.
1556 elsif ($^O eq 'VMS') {
1557 $console = 'sys$command';
1560 # Keep this penultimate, on the grounds that it satisfies a wide variety of
1561 # Unix-like systems that would otherwise need to be identified individually.
1563 =item * Unix - use F</dev/tty>.
1567 elsif ( -e "/dev/tty" ) {
1568 $console = "/dev/tty";
1574 _db_warn("Can't figure out your console, using stdin");
1582 Several other systems don't use a specific console. We C<undef $console>
1583 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1584 with a slave editor).
1588 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1590 # /dev/tty is binary. use stdin for textmode
1594 if ( $^O eq 'NetWare' ) {
1596 # /dev/tty is binary. use stdin for textmode
1600 # In OS/2, we need to use STDIN to get textmode too, even though
1601 # it pretty much looks like Unix otherwise.
1602 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1609 If there is a TTY hanging around from a parent, we use that as the console.
1613 $console = $tty if defined $tty;
1615 =head2 SOCKET HANDLING
1617 The debugger is capable of opening a socket and carrying out a debugging
1618 session over the socket.
1620 If C<RemotePort> was defined in the options, the debugger assumes that it
1621 should try to start a debugging session on that port. It builds the socket
1622 and then tries to connect the input and output filehandles to it.
1626 # Handle socket stuff.
1628 if ( defined $remoteport ) {
1630 # If RemotePort was defined in the options, connect input and output
1632 $IN = $OUT = connect_remoteport();
1633 } ## end if (defined $remoteport)
1637 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1638 this is probably a situation where multiple debuggers are running (for example,
1639 a backticked command that starts up another debugger). We create a new IN and
1640 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1648 # Two debuggers running (probably a system or a backtick that invokes
1649 # the debugger itself under the running one). create a new IN and OUT
1650 # filehandle, and do the necessary mojo to create a new tty if we
1651 # know how, and we can.
1652 create_IN_OUT(4) if $CreateTTY & 4;
1655 # If we have a console, check to see if there are separate ins and
1656 # outs to open. (They are assumed identical if not.)
1658 my ( $i, $o ) = split /,/, $console;
1659 $o = $i unless defined $o;
1661 # read/write on in, or just read, or read on STDIN.
1662 open( IN, '+<', $i )
1663 || open( IN, '<', $i )
1664 || open( IN, "<&STDIN" );
1666 # read/write/create/clobber out, or write/create/clobber out,
1667 # or merge with STDERR, or merge with STDOUT.
1668 open( OUT, '+>', $o )
1669 || open( OUT, '>', $o )
1670 || open( OUT, ">&STDERR" )
1671 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1673 } ## end if ($console)
1674 elsif ( not defined $console ) {
1676 # No console. Open STDIN.
1677 open( IN, "<&STDIN" );
1679 # merge with STDERR, or with STDOUT.
1680 open( OUT, ">&STDERR" )
1681 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1682 $console = 'STDIN/OUT';
1683 } ## end elsif (not defined $console)
1685 # Keep copies of the filehandles so that when the pager runs, it
1686 # can close standard input without clobbering ours.
1687 if ($console or (not defined($console))) {
1691 } ## end elsif (from if(defined $remoteport))
1693 # Unbuffer DB::OUT. We need to see responses right away.
1696 # Line info goes to debugger output unless pointed elsewhere.
1697 # Pointing elsewhere makes it possible for slave editors to
1698 # keep track of file and position. We have both a filehandle
1699 # and a I/O description to keep track of.
1700 $LINEINFO = $OUT unless defined $LINEINFO;
1701 $lineinfo = $console unless defined $lineinfo;
1702 # share($LINEINFO); # <- unable to share globs
1707 To finish initialization, we show the debugger greeting,
1708 and then call the C<afterinit()> subroutine if there is one.
1712 # Show the debugger greeting.
1713 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1714 unless ($runnonstop) {
1717 if ( $term_pid eq '-1' ) {
1718 print $OUT "\nDaughter DB session started...\n";
1721 print $OUT "\nLoading DB routines from $header\n";
1724 $slave_editor ? "enabled" : "available", ".\n"
1727 "\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
1728 } ## end else [ if ($term_pid eq '-1')
1729 } ## end unless ($runnonstop)
1730 } ## end else [ if ($notty)
1732 # XXX This looks like a bug to me.
1733 # Why copy to @ARGS and then futz with @args?
1736 # Make sure backslashes before single quotes are stripped out, and
1737 # keep args unless they are numeric (XXX why?)
1738 # s/\'/\\\'/g; # removed while not justified understandably
1739 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1742 # If there was an afterinit() sub defined, call it. It will get
1743 # executed in our scope, so it can fiddle with debugger globals.
1744 if ( defined &afterinit ) { # May be defined in $rcfile
1748 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1749 use vars qw($I_m_init);
1753 ############################################################ Subroutines
1759 This gigantic subroutine is the heart of the debugger. Called before every
1760 statement, its job is to determine if a breakpoint has been reached, and
1761 stop if so; read commands from the user, parse them, and execute
1762 them, and then send execution off to the next statement.
1764 Note that the order in which the commands are processed is very important;
1765 some commands earlier in the loop will actually alter the C<$cmd> variable
1766 to create other commands to be executed later. This is all highly I<optimized>
1767 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1768 see what's happening in any given command.
1772 # $cmd cannot be an our() variable unfortunately (possible perl bug?).
1802 sub _DB__determine_if_we_should_break
1804 # if we have something here, see if we should break.
1805 # $stop is lexical and local to this block - $action on the other hand
1810 && _is_breakpoint_enabled($filename, $line)
1811 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1814 # Stop if the stop criterion says to just stop.
1815 if ( $stop eq '1' ) {
1819 # It's a conditional stop; eval it in the user's context and
1820 # see if we should stop. If so, remove the one-time sigil.
1822 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1823 # The &-call is here to ascertain the mutability of @_.
1825 # If the breakpoint is temporary, then delete its enabled status.
1826 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1827 _cancel_breakpoint_temp_enabled_status($filename, $line);
1830 } ## end if ($dbline{$line} && ...
1833 sub _DB__is_finished {
1834 if ($finished and $level <= 1) {
1843 sub _DB__read_next_cmd
1847 # We have a terminal, or can get one ...
1852 # ... and it belongs to this PID or we get one for this PID ...
1853 if ($term_pid != $$) {
1857 # ... and we got a line of command input ...
1858 $cmd = DB::readline(
1859 "$pidprompt $tid DB"
1862 . ( '>' x $level ) . " "
1865 return defined($cmd);
1868 sub _DB__trim_command_and_return_first_component {
1871 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1872 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1874 # A single-character debugger command can be immediately followed by its
1875 # argument if they aren't both alphanumeric; otherwise require space
1876 # between commands and arguments:
1877 my ($verb, $args) = $cmd =~ m{\A(.\b|\S*)\s*(.*)}s;
1879 $obj->cmd_verb($verb);
1880 $obj->cmd_args($args);
1885 sub _DB__handle_f_command {
1888 if ($file = $obj->cmd_args) {
1889 # help for no arguments (old-style was return from sub).
1892 "The old f command is now the r command.\n"; # hint
1893 print $OUT "The new f command switches filenames.\n";
1895 } ## end if (!$file)
1897 # if not in magic file list, try a close match.
1898 if ( !defined $main::{ '_<' . $file } ) {
1899 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1901 $try = substr( $try, 2 );
1902 print $OUT "Choosing $try matching '$file':\n";
1905 } ## end if (($try) = grep(m#^_<.*$file#...
1906 } ## end if (!defined $main::{ ...
1908 # If not successfully switched now, we failed.
1909 if ( !defined $main::{ '_<' . $file } ) {
1910 print $OUT "No file matching '$file' is loaded.\n";
1914 # We switched, so switch the debugger internals around.
1915 elsif ( $file ne $filename ) {
1916 *dbline = $main::{ '_<' . $file };
1921 } ## end elsif ($file ne $filename)
1923 # We didn't switch; say we didn't.
1925 print $OUT "Already in $file.\n";
1933 sub _DB__handle_dot_command {
1937 if ($obj->_is_full('.')) {
1938 $incr = -1; # stay at current line
1940 # Reset everything to the old location.
1942 $filename = $filename_ini;
1943 *dbline = $main::{ '_<' . $filename };
1947 print_lineinfo($obj->position());
1954 sub _DB__handle_y_command {
1957 if (my ($match_level, $match_vars)
1958 = $obj->cmd_args =~ /\A(?:(\d*)\s*(.*))?\z/) {
1960 # See if we've got the necessary support.
1963 pop @INC if $INC[-1] eq '.';
1964 require PadWalker; PadWalker->VERSION(0.08) }) {
1968 ? "PadWalker module not found - please install\n"
1974 # Load up dumpvar if we don't have it. If we can, that is.
1975 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1976 defined &main::dumpvar
1977 or print $OUT "dumpvar.pl not available.\n"
1980 # Got all the modules we need. Find them and print them.
1981 my @vars = split( ' ', $match_vars || '' );
1984 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 2 ) };
1986 # Oops. Can't find it.
1993 # Show the desired vars with dumplex().
1994 my $savout = select($OUT);
1996 # Have dumplex dump the lexicals.
1997 foreach my $key (sort keys %$h) {
1998 dumpvar::dumplex( $key, $h->{$key},
1999 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
2007 sub _DB__handle_c_command {
2010 my $i = $obj->cmd_args;
2012 if ($i =~ m#\A[\w:]*\z#) {
2014 # Hey, show's over. The debugged program finished
2015 # executing already.
2016 next CMD if _DB__is_finished();
2018 # Capture the place to put a one-time break.
2021 # Probably not needed, since we finish an interactive
2022 # sub-session anyway...
2023 # local $filename = $filename;
2024 # local *dbline = *dbline; # XXX Would this work?!
2026 # The above question wonders if localizing the alias
2027 # to the magic array works or not. Since it's commented
2028 # out, we'll just leave that to speculation for now.
2030 # If the "subname" isn't all digits, we'll assume it
2031 # is a subroutine name, and try to find it.
2032 if ( $subname =~ /\D/ ) { # subroutine name
2033 # Qualify it to the current package unless it's
2034 # already qualified.
2035 $subname = $package . "::" . $subname
2036 unless $subname =~ /::/;
2038 # find_sub will return "file:line_number" corresponding
2039 # to where the subroutine is defined; we call find_sub,
2040 # break up the return value, and assign it in one
2042 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2044 # Force the line number to be numeric.
2047 # If we got a line number, we found the sub.
2050 # Switch all the debugger's internals around so
2051 # we're actually working with that file.
2053 *dbline = $main::{ '_<' . $filename };
2055 # Mark that there's a breakpoint in this file.
2056 $had_breakpoints{$filename} |= 1;
2058 # Scan forward to the first executable line
2059 # after the 'sub whatever' line.
2062 while ($dbline[$_line_num] == 0 && $_line_num< $max)
2069 # We didn't find a sub by that name.
2071 print $OUT "Subroutine $subname not found.\n";
2074 } ## end if ($subname =~ /\D/)
2076 # At this point, either the subname was all digits (an
2077 # absolute line-break request) or we've scanned through
2078 # the code following the definition of the sub, looking
2079 # for an executable, which we may or may not have found.
2081 # If $i (which we set $subname from) is non-zero, we
2082 # got a request to break at some line somewhere. On
2083 # one hand, if there wasn't any real subroutine name
2084 # involved, this will be a request to break in the current
2085 # file at the specified line, so we have to check to make
2086 # sure that the line specified really is breakable.
2088 # On the other hand, if there was a subname supplied, the
2089 # preceding block has moved us to the proper file and
2090 # location within that file, and then scanned forward
2091 # looking for the next executable line. We have to make
2092 # sure that one was found.
2094 # On the gripping hand, we can't do anything unless the
2095 # current value of $i points to a valid breakable line.
2100 if ( $dbline[$i] == 0 ) {
2101 print $OUT "Line $i not breakable.\n";
2105 # Yes. Set up the one-time-break sigil.
2106 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2107 _enable_breakpoint_temp_enabled_status($filename, $i);
2110 # Turn off stack tracing from here up.
2111 for my $j (0 .. $stack_depth) {
2120 sub _DB__handle_forward_slash_command {
2123 # The pattern as a string.
2124 use vars qw($inpat);
2126 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2128 # Remove the final slash.
2129 $inpat =~ s:([^\\])/$:$1:;
2131 # If the pattern isn't null ...
2132 if ( $inpat ne "" ) {
2134 # Turn off warn and die processing for a bit.
2135 local $SIG{__DIE__};
2136 local $SIG{__WARN__};
2138 # Create the pattern.
2139 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2142 # Oops. Bad pattern. No biscuit.
2143 # Print the eval error and go back for more
2149 } ## end if ($inpat ne "")
2151 # Set up to stop on wrap-around.
2154 # Don't move off the current line.
2157 my $pat = $obj->pat;
2159 # Done in eval so nothing breaks if the pattern
2160 # does something weird.
2165 # Move ahead one line.
2168 # Wrap if we pass the last line.
2169 if ($start > $max) {
2173 # Stop if we have gotten back to this line again,
2174 last if ($start == $end);
2176 # A hit! (Note, though, that we are doing
2177 # case-insensitive matching. Maybe a qr//
2178 # expression would be better, so the user could
2179 # do case-sensitive matching if desired.
2180 if ($dbline[$start] =~ m/$pat/i) {
2181 if ($slave_editor) {
2182 # Handle proper escaping in the slave.
2183 print {$OUT} "\032\032$filename:$start:0\n";
2186 # Just print the line normally.
2187 print {$OUT} "$start:\t",$dbline[$start],"\n";
2189 # And quit since we found something.
2199 # If we wrapped, there never was a match.
2200 if ( $start == $end ) {
2201 print {$OUT} "/$pat/: not found\n";
2209 sub _DB__handle_question_mark_command {
2212 # ? - backward pattern search.
2213 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2215 # Get the pattern, remove trailing question mark.
2216 $inpat =~ s:([^\\])\?$:$1:;
2218 # If we've got one ...
2219 if ( $inpat ne "" ) {
2221 # Turn off die & warn handlers.
2222 local $SIG{__DIE__};
2223 local $SIG{__WARN__};
2224 eval '$inpat =~ m' . "\a$inpat\a";
2228 # Ouch. Not good. Print the error.
2233 } ## end if ($inpat ne "")
2235 # Where we are now is where to stop after wraparound.
2238 # Don't move away from this line.
2241 my $pat = $obj->pat;
2242 # Search inside the eval to prevent pattern badness
2250 # Wrap if we pass the first line.
2252 $start = $max if ($start <= 0);
2254 # Quit if we get back where we started,
2255 last if ($start == $end);
2258 if ($dbline[$start] =~ m/$pat/i) {
2259 if ($slave_editor) {
2260 # Yep, follow slave editor requirements.
2261 print $OUT "\032\032$filename:$start:0\n";
2264 # Yep, just print normally.
2265 print $OUT "$start:\t",$dbline[$start],"\n";
2274 # Say we failed if the loop never found anything,
2275 if ( $start == $end ) {
2276 print {$OUT} "?$pat?: not found\n";
2284 sub _DB__handle_restart_and_rerun_commands {
2287 my $cmd_cmd = $obj->cmd_verb;
2288 my $cmd_params = $obj->cmd_args;
2289 # R - restart execution.
2290 # rerun - controlled restart execution.
2291 if ($cmd_cmd eq 'rerun' or $cmd_params eq '') {
2293 # Change directory to the initial current working directory on
2294 # the script startup, so if the debugged program changed the
2295 # directory, then we will still be able to find the path to the
2296 # the program. (perl 5 RT #121509 ).
2297 chdir ($_initial_cwd);
2299 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
2301 # Close all non-system fds for a clean restart. A more
2302 # correct method would be to close all fds that were not
2303 # open when the process started, but this seems to be
2304 # hard. See "debugger 'R'estart and open database
2305 # connections" on p5p.
2307 my $max_fd = 1024; # default if POSIX can't be loaded
2308 if (eval { require POSIX }) {
2309 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
2312 if (defined $max_fd) {
2313 foreach ($^F+1 .. $max_fd-1) {
2314 next unless open FD_TO_CLOSE, "<&=$_";
2319 # And run Perl again. We use exec() to keep the
2320 # PID stable (and that way $ini_pids is still valid).
2321 exec(@args) or print {$OUT} "exec failed: $!\n";
2329 sub _DB__handle_run_command_in_pager_command {
2332 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
2333 if ( $pager =~ /^\|/ ) {
2335 # Default pager is into a pipe. Redirect I/O.
2336 open( SAVEOUT, ">&STDOUT" )
2337 || _db_warn("Can't save STDOUT");
2338 open( STDOUT, ">&OUT" )
2339 || _db_warn("Can't redirect STDOUT");
2340 } ## end if ($pager =~ /^\|/)
2343 # Not into a pipe. STDOUT is safe.
2344 open( SAVEOUT, ">&OUT" ) || _db_warn("Can't save DB::OUT");
2347 # Fix up environment to record we have less if so.
2350 unless ( $obj->piped(scalar ( open( OUT, $pager ) ) ) ) {
2352 # Couldn't open pipe to pager.
2353 _db_warn("Can't pipe output to '$pager'");
2354 if ( $pager =~ /^\|/ ) {
2356 # Redirect I/O back again.
2357 open( OUT, ">&STDOUT" ) # XXX: lost message
2358 || _db_warn("Can't restore DB::OUT");
2359 open( STDOUT, ">&SAVEOUT" )
2360 || _db_warn("Can't restore STDOUT");
2362 } ## end if ($pager =~ /^\|/)
2365 # Redirect I/O. STDOUT already safe.
2366 open( OUT, ">&STDOUT" ) # XXX: lost message
2367 || _db_warn("Can't restore DB::OUT");
2370 } ## end unless ($piped = open(OUT,...
2372 # Set up broken-pipe handler if necessary.
2373 $SIG{PIPE} = \&DB::catch
2375 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
2378 # Save current filehandle, and put it back.
2379 $obj->selected(scalar( select(OUT) ));
2380 # Don't put it back if pager was a pipe.
2381 if ($cmd !~ /\A\|\|/)
2383 select($obj->selected());
2387 # Trim off the pipe symbols and run the command now.
2388 $cmd =~ s#\A\|+\s*##;
2395 sub _DB__handle_m_command {
2398 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2403 # m expr - set up DB::eval to do the work
2404 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2405 $onetimeDump = 'methods'; # method output gets used there
2411 sub _DB__at_end_of_every_command {
2414 # At the end of every command:
2417 # Unhook the pipe mechanism now.
2418 if ( $pager =~ /^\|/ ) {
2420 # No error from the child.
2423 # we cannot warn here: the handle is missing --tchrist
2424 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
2426 # most of the $? crud was coping with broken cshisms
2427 # $? is explicitly set to 0, so this never runs.
2429 print SAVEOUT "Pager '$pager' failed: ";
2431 print SAVEOUT "shell returned -1\n";
2434 print SAVEOUT ( $? & 127 )
2435 ? " (SIG#" . ( $? & 127 ) . ")"
2436 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
2439 print SAVEOUT "status ", ( $? >> 8 ), "\n";
2443 # Reopen filehandle for our output (if we can) and
2444 # restore STDOUT (if we can).
2445 open( OUT, ">&STDOUT" ) || _db_warn("Can't restore DB::OUT");
2446 open( STDOUT, ">&SAVEOUT" )
2447 || _db_warn("Can't restore STDOUT");
2449 # Turn off pipe exception handler if necessary.
2450 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
2452 # Will stop ignoring SIGPIPE if done like nohup(1)
2453 # does SIGINT but Perl doesn't give us a choice.
2454 } ## end if ($pager =~ /^\|/)
2457 # Non-piped "pager". Just restore STDOUT.
2458 open( OUT, ">&SAVEOUT" ) || _db_warn("Can't restore DB::OUT");
2461 # Let Readline know about the new filehandles.
2462 reset_IN_OUT( \*IN, \*OUT );
2464 # Close filehandle pager was using, restore the normal one
2468 if ($obj->selected() ne "") {
2469 select($obj->selected);
2475 } ## end if ($piped)
2480 sub _DB__handle_watch_expressions
2484 if ( $DB::trace & 2 ) {
2485 for my $n (0 .. $#DB::to_watch) {
2486 $DB::evalarg = $DB::to_watch[$n];
2487 local $DB::onetimeDump; # Tell DB::eval() to not output results
2489 # Fix context DB::eval() wants to return an array, but
2490 # we need a scalar here.
2491 my ($val) = join( "', '", DB::eval(@_) );
2492 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
2495 if ( $val ne $DB::old_watch[$n] ) {
2497 # Yep! Show the difference, and fake an interrupt.
2499 print {$DB::OUT} <<EOP;
2500 Watchpoint $n:\t$DB::to_watch[$n] changed:
2501 old value:\t$DB::old_watch[$n]
2504 $DB::old_watch[$n] = $val;
2505 } ## end if ($val ne $old_watch...
2506 } ## end for my $n (0 ..
2507 } ## end if ($trace & 2)
2514 # 'v' is the value (i.e: method name or subroutine ref).
2515 # 's' is subroutine.
2522 '-' => { t => 'm', v => '_handle_dash_command', },
2523 '.' => { t => 's', v => \&_DB__handle_dot_command, },
2524 '=' => { t => 'm', v => '_handle_equal_sign_command', },
2525 'H' => { t => 'm', v => '_handle_H_command', },
2526 'S' => { t => 'm', v => '_handle_S_command', },
2527 'T' => { t => 'm', v => '_handle_T_command', },
2528 'W' => { t => 'm', v => '_handle_W_command', },
2529 'c' => { t => 's', v => \&_DB__handle_c_command, },
2530 'f' => { t => 's', v => \&_DB__handle_f_command, },
2531 'm' => { t => 's', v => \&_DB__handle_m_command, },
2532 'n' => { t => 'm', v => '_handle_n_command', },
2533 'p' => { t => 'm', v => '_handle_p_command', },
2534 'q' => { t => 'm', v => '_handle_q_command', },
2535 'r' => { t => 'm', v => '_handle_r_command', },
2536 's' => { t => 'm', v => '_handle_s_command', },
2537 'save' => { t => 'm', v => '_handle_save_command', },
2538 'source' => { t => 'm', v => '_handle_source_command', },
2539 't' => { t => 'm', v => '_handle_t_command', },
2540 'w' => { t => 'm', v => '_handle_w_command', },
2541 'x' => { t => 'm', v => '_handle_x_command', },
2542 'y' => { t => 's', v => \&_DB__handle_y_command, },
2543 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, }
2545 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, }
2546 qw(enable disable)),
2548 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, },
2550 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, }
2551 qw(a A b B e E h i l L M o O v w W)),
2557 # lock the debugger and get the thread id for the prompt
2561 my ($prefix, $after, $infix);
2567 if ($ENV{PERL5DB_THREADED}) {
2568 $tid = eval { "[".threads->tid."]" };
2574 my $obj = DB::Obj->new(
2576 position => \$position,
2579 explicit_stop => \$explicit_stop,
2581 cmd_args => \$cmd_args,
2582 cmd_verb => \$cmd_verb,
2585 selected => \$selected,
2589 $obj->_DB_on_init__initialize_globals(@_);
2591 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2592 # The code being debugged may have altered them.
2595 # Since DB::DB gets called after every line, we can use caller() to
2596 # figure out where we last were executing. Sneaky, eh? This works because
2597 # caller is returning all the extra information when called from the
2599 local ( $package, $filename, $line ) = caller;
2600 $filename_ini = $filename;
2602 # set up the context for DB::eval, so it can properly execute
2603 # code on behalf of the user. We add the package in so that the
2604 # code is eval'ed in the proper package (not in the debugger!).
2605 local $usercontext = _calc_usercontext($package);
2607 # Create an alias to the active file magical array to simplify
2609 local (*dbline) = $main::{ '_<' . $filename };
2611 # Last line in the program.
2614 # The &-call is here to ascertain the mutability of @_.
2615 &_DB__determine_if_we_should_break;
2617 # Preserve the current stop-or-not, and see if any of the W
2618 # (watch expressions) has changed.
2619 my $was_signal = $signal;
2621 # If we have any watch expressions ...
2622 _DB__handle_watch_expressions($obj);
2624 =head2 C<watchfunction()>
2626 C<watchfunction()> is a function that can be defined by the user; it is a
2627 function which will be run on each entry to C<DB::DB>; it gets the
2628 current package, filename, and line as its parameters.
2630 The watchfunction can do anything it likes; it is executing in the
2631 debugger's context, so it has access to all of the debugger's internal
2632 data structures and functions.
2634 C<watchfunction()> can control the debugger's actions. Any of the following
2635 will cause the debugger to return control to the user's program after
2636 C<watchfunction()> executes:
2642 Returning a false value from the C<watchfunction()> itself.
2646 Altering C<$single> to a false value.
2650 Altering C<$signal> to a false value.
2654 Turning off the C<4> bit in C<$trace> (this also disables the
2655 check for C<watchfunction()>. This can be done with
2663 # If there's a user-defined DB::watchfunction, call it with the
2664 # current package, filename, and line. The function executes in
2666 if ( $trace & 4 ) { # User-installed watch
2668 if watchfunction( $package, $filename, $line )
2671 and not( $trace & ~4 );
2672 } ## end if ($trace & 4)
2674 # Pick up any alteration to $signal in the watchfunction, and
2675 # turn off the signal now.
2676 $was_signal = $signal;
2679 =head2 GETTING READY TO EXECUTE COMMANDS
2681 The debugger decides to take control if single-step mode is on, the
2682 C<t> command was entered, or the user generated a signal. If the program
2683 has fallen off the end, we set things up so that entering further commands
2684 won't cause trouble, and we say that the program is over.
2688 # Make sure that we always print if asked for explicitly regardless
2689 # of $trace_to_depth .
2690 $explicit_stop = ($single || $was_signal);
2692 # Check to see if we should grab control ($single true,
2693 # trace set appropriately, or we got a signal).
2694 if ( $explicit_stop || ( $trace & 1 ) ) {
2695 $obj->_DB__grab_control(@_);
2696 } ## end if ($single || ($trace...
2700 If there's an action to be executed for the line we stopped at, execute it.
2701 If there are any preprompt actions, execute those as well.
2705 # If there's an action, do it now.
2708 # The &-call is here to ascertain the mutability of @_.
2712 # Are we nested another level (e.g., did we evaluate a function
2713 # that had a breakpoint in it at the debugger prompt)?
2714 if ( $single || $was_signal ) {
2716 # Yes, go down a level.
2717 local $level = $level + 1;
2719 # Do any pre-prompt actions.
2720 foreach $evalarg (@$pre) {
2721 # The &-call is here to ascertain the mutability of @_.
2725 # Complain about too much recursion if we passed the limit.
2727 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2730 # The line we're currently on. Set $incr to -1 to stay here
2731 # until we get a command that tells us to advance.
2733 $incr = -1; # for backward motion.
2735 # Tack preprompt debugger actions ahead of any actual input.
2736 @typeahead = ( @$pretype, @typeahead );
2738 =head2 WHERE ARE WE?
2740 XXX Relocate this section?
2742 The debugger normally shows the line corresponding to the current line of
2743 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2744 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2746 C<$incr> controls by how many lines the I<current> line should move forward
2747 after a command is executed. If set to -1, this indicates that the I<current>
2748 line shouldn't change.
2750 C<$start> is the I<current> line. It is used for things like knowing where to
2751 move forwards or backwards from when doing an C<L> or C<-> command.
2753 C<$max> tells the debugger where the last line of the current file is. It's
2754 used to terminate loops most often.
2756 =head2 THE COMMAND LOOP
2758 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2765 The outer part of the loop, starting at the C<CMD> label. This loop
2766 reads a command and then executes it.
2770 The inner part of the loop, starting at the C<PIPE> label. This part
2771 is wholly contained inside the C<CMD> block and only executes a command.
2772 Used to handle commands running inside a pager.
2776 So why have two labels to restart the loop? Because sometimes, it's easier to
2777 have a command I<generate> another command and then re-execute the loop to do
2778 the new command. This is faster, but perhaps a bit more convoluted.
2782 # The big command dispatch loop. It keeps running until the
2783 # user yields up control again.
2785 # If we have a terminal for input, and we get something back
2786 # from readline(), keep on processing.
2789 while (_DB__read_next_cmd($tid))
2793 # ... try to execute the input as debugger commands.
2795 # Don't stop running.
2798 # No signal is active.
2801 # Handle continued commands (ending with \):
2802 if ($cmd =~ s/\\\z/\n/) {
2803 $cmd .= DB::readline(" cont: ");
2807 =head4 The null command
2809 A newline entered by itself means I<re-execute the last command>. We grab the
2810 command out of C<$laststep> (where it was recorded previously), and copy it
2811 back into C<$cmd> to be executed below. If there wasn't any previous command,
2812 we'll do nothing below (no command will match). If there was, we also save it
2813 in the command history and fall through to allow the command parsing to pick
2818 # Empty input means repeat the last command.
2822 chomp($cmd); # get rid of the annoying extra newline
2823 if (length($cmd) >= 2) {
2824 push( @hist, $cmd );
2826 push( @truehist, $cmd );
2830 # This is a restart point for commands that didn't arrive
2831 # via direct user input. It allows us to 'redo PIPE' to
2832 # re-execute command processing without reading a new command.
2834 _DB__trim_command_and_return_first_component($obj);
2836 =head3 COMMAND ALIASES
2838 The debugger can create aliases for commands (these are stored in the
2839 C<%alias> hash). Before a command is executed, the command loop looks it up
2840 in the alias hash and substitutes the contents of the alias for the command,
2841 completely replacing it.
2845 # See if there's an alias for the command, and set it up if so.
2846 if ( $alias{$cmd_verb} ) {
2848 # Squelch signal handling; we want to keep control here
2849 # if something goes loco during the alias eval.
2850 local $SIG{__DIE__};
2851 local $SIG{__WARN__};
2853 # This is a command, so we eval it in the DEBUGGER's
2854 # scope! Otherwise, we can't see the special debugger
2855 # variables, or get to the debugger's subs. (Well, we
2856 # _could_, but why make it even more complicated?)
2857 eval "\$cmd =~ $alias{$cmd_verb}";
2860 print $OUT "Couldn't evaluate '$cmd_verb' alias: $@";
2863 _DB__trim_command_and_return_first_component($obj);
2864 } ## end if ($alias{$cmd_verb})
2866 =head3 MAIN-LINE COMMANDS
2868 All of these commands work up to and after the program being debugged has
2873 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2874 try to execute further, cleaning any restart-related stuff out of the
2875 environment, and executing with the last value of C<$?>.
2879 # All of these commands were remapped in perl 5.8.0;
2880 # we send them off to the secondary dispatcher (see below).
2881 $obj->_handle_special_char_cmd_wrapper_commands;
2882 _DB__trim_command_and_return_first_component($obj);
2884 if (my $cmd_rec = $cmd_lookup{$cmd_verb}) {
2885 my $type = $cmd_rec->{t};
2886 my $val = $cmd_rec->{v};
2890 elsif ($type eq 's') {
2895 =head4 C<t> - trace [n]
2897 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2898 If level is specified, set C<$trace_to_depth>.
2900 =head4 C<S> - list subroutines matching/not matching a pattern
2902 Walks through C<%sub>, checking to see whether or not to print the name.
2904 =head4 C<X> - list variables in current package
2906 Since the C<V> command actually processes this, just change this to the
2907 appropriate C<V> command and fall through.
2909 =head4 C<V> - list variables
2911 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2913 =head4 C<x> - evaluate and print an expression
2915 Hands the expression off to C<DB::eval>, setting it up to print the value
2916 via C<dumpvar.pl> instead of just printing it directly.
2918 =head4 C<m> - print methods
2920 Just uses C<DB::methods> to determine what methods are available.
2922 =head4 C<f> - switch files
2924 Switch to a different filename.
2926 =head4 C<.> - return to last-executed line.
2928 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2929 and then we look up the line in the magical C<%dbline> hash.
2931 =head4 C<-> - back one window
2933 We change C<$start> to be one window back; if we go back past the first line,
2934 we set it to be the first line. We set C<$incr> to put us back at the
2935 currently-executing line, and then put a C<l $start +> (list one window from
2936 C<$start>) in C<$cmd> to be executed later.
2938 =head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
2940 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2941 problems, most notably that the default case of several commands destroying
2942 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2943 retain the old commands for those who were used to using them or who preferred
2944 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2945 deal with them instead of processing them in-line.
2947 =head4 C<y> - List lexicals in higher scope
2949 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2950 above the current one and then displays then using C<dumpvar.pl>.
2952 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2954 All of the commands below this point don't work after the program being
2955 debugged has ended. All of them check to see if the program has ended; this
2956 allows the commands to be relocated without worrying about a 'line of
2957 demarcation' above which commands can be entered anytime, and below which
2960 =head4 C<n> - single step, but don't trace down into subs
2962 Done by setting C<$single> to 2, which forces subs to execute straight through
2963 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2964 so a null command knows what to re-execute.
2966 =head4 C<s> - single-step, entering subs
2968 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2969 subs. Also saves C<s> as C<$lastcmd>.
2971 =head4 C<c> - run continuously, setting an optional breakpoint
2973 Most of the code for this command is taken up with locating the optional
2974 breakpoint, which is either a subroutine name or a line number. We set
2975 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2976 in this and all call levels above this one.
2978 =head4 C<r> - return from a subroutine
2980 For C<r> to work properly, the debugger has to stop execution again
2981 immediately after the return is executed. This is done by forcing
2982 single-stepping to be on in the call level above the current one. If
2983 we are printing return values when a C<r> is executed, set C<$doret>
2984 appropriately, and force us out of the command loop.
2986 =head4 C<T> - stack trace
2988 Just calls C<DB::print_trace>.
2990 =head4 C<w> - List window around current line.
2992 Just calls C<DB::cmd_w>.
2994 =head4 C<W> - watch-expression processing.
2996 Just calls C<DB::cmd_W>.
2998 =head4 C</> - search forward for a string in the source
3000 We take the argument and treat it as a pattern. If it turns out to be a
3001 bad one, we return the error we got from trying to C<eval> it and exit.
3002 If not, we create some code to do the search and C<eval> it so it can't
3007 _DB__handle_forward_slash_command($obj);
3009 =head4 C<?> - search backward for a string in the source
3011 Same as for C</>, except the loop runs backwards.
3015 _DB__handle_question_mark_command($obj);
3017 =head4 C<$rc> - Recall command
3019 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
3020 that the terminal supports history). It finds the command required, puts it
3021 into C<$cmd>, and redoes the loop to execute it.
3025 # $rc - recall command.
3026 $obj->_handle_rc_recall_command;
3028 =head4 C<$sh$sh> - C<system()> command
3030 Calls the C<_db_system()> to handle the command. This keeps the C<STDIN> and
3031 C<STDOUT> from getting messed up.
3035 $obj->_handle_sh_command;
3037 =head4 C<$rc I<pattern> $rc> - Search command history
3039 Another command to manipulate C<@hist>: this one searches it with a pattern.
3040 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
3044 $obj->_handle_rc_search_history_command;
3046 =head4 C<$sh> - Invoke a shell
3048 Uses C<_db_system()> to invoke a shell.
3052 =head4 C<$sh I<command>> - Force execution of a command in a shell
3054 Like the above, but the command is passed to the shell. Again, we use
3055 C<_db_system()> to avoid problems with C<STDIN> and C<STDOUT>.
3057 =head4 C<H> - display commands in history
3059 Prints the contents of C<@hist> (if any).
3061 =head4 C<man, doc, perldoc> - look up documentation
3063 Just calls C<runman()> to print the appropriate document.
3067 $obj->_handle_doc_command;
3071 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3072 the bottom of the loop.
3074 =head4 C<=> - define command alias
3076 Manipulates C<%alias> to add or list command aliases.
3078 =head4 C<source> - read commands from a file.
3080 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3083 =head4 C<enable> C<disable> - enable or disable breakpoints
3085 This enables or disables breakpoints.
3087 =head4 C<save> - send current history to a file
3089 Takes the complete history, (not the shrunken version you see with C<H>),
3090 and saves it to the given filename, so it can be replayed using C<source>.
3092 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3094 =head4 C<R> - restart
3096 Restart the debugger session.
3098 =head4 C<rerun> - rerun the current session
3100 Return to any given position in the B<true>-history list
3102 =head4 C<|, ||> - pipe output through the pager.
3104 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3105 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3106 pipe to the pager (restoring the output filehandles if this fails). If this
3107 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3108 set C<$signal>, sending us back into the debugger.
3110 We then trim off the pipe symbols and C<redo> the command loop at the
3111 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3116 # || - run command in the pager, with output to DB::OUT.
3117 _DB__handle_run_command_in_pager_command($obj);
3119 =head3 END OF COMMAND PARSING
3121 Anything left in C<$cmd> at this point is a Perl expression that we want to
3122 evaluate. We'll always evaluate in the user's context, and fully qualify
3123 any variables we might want to address in the C<DB> package.
3129 # trace an expression
3130 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3132 # Make sure the flag that says "the debugger's running" is
3133 # still on, to make sure we get control again.
3134 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3136 # Run *our* eval that executes in the caller's context.
3137 # The &-call is here to ascertain the mutability of @_.
3140 # Turn off the one-time-dump stuff now.
3142 $onetimeDump = undef;
3143 $onetimedumpDepth = undef;
3145 elsif ( $term_pid == $$ ) {
3146 eval { # May run under miniperl, when not available...
3151 # XXX If this is the master pid, print a newline.
3154 } ## end while (($term || &setterm...
3156 =head3 POST-COMMAND PROCESSING
3158 After each command, we check to see if the command output was piped anywhere.
3159 If so, we go through the necessary code to unhook the pipe and go back to
3160 our standard filehandles for input and output.
3165 _DB__at_end_of_every_command($obj);
3168 =head3 COMMAND LOOP TERMINATION
3170 When commands have finished executing, we come here. If the user closed the
3171 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3172 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3173 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3174 The interpreter will then execute the next line and then return control to us
3179 # No more commands? Quit.
3180 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
3182 # Evaluate post-prompt commands.
3183 foreach $evalarg (@$post) {
3184 # The &-call is here to ascertain the mutability of @_.
3187 } # if ($single || $signal)
3189 # Put the user's globals back where you found them.
3190 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3194 # Because DB::Obj is used above,
3196 # my $obj = DB::Obj->new(
3198 # The following package declaration must come before that,
3199 # or else runtime errors will occur with
3201 # PERLDB_OPTS="autotrace nonstop"
3211 my $self = bless {}, $class;
3219 my ($self, $args) = @_;
3221 %{$self} = (%$self, %$args);
3228 foreach my $slot_name (qw(
3229 after explicit_stop infix pat piped position prefix selected cmd_verb
3232 my $slot = $slot_name;
3237 ${ $self->{$slot} } = shift;
3240 return ${ $self->{$slot} };
3243 *{"append_to_$slot"} = sub {
3247 return $self->$slot($self->$slot . $s);
3252 sub _DB_on_init__initialize_globals
3256 # Check for whether we should be running continuously or not.
3257 # _After_ the perl program is compiled, $single is set to 1:
3258 if ( $single and not $second_time++ ) {
3260 # Options say run non-stop. Run until we get an interrupt.
3261 if ($runnonstop) { # Disable until signal
3262 # If there's any call stack in place, turn off single
3263 # stepping into subs throughout the stack.
3264 for my $i (0 .. $stack_depth) {
3268 # And we are now no longer in single-step mode.
3271 # If we simply returned at this point, we wouldn't get
3272 # the trace info. Fall on through.
3274 } ## end if ($runnonstop)
3276 elsif ($ImmediateStop) {
3278 # We are supposed to stop here; XXX probably a break.
3279 $ImmediateStop = 0; # We've processed it; turn it off
3280 $signal = 1; # Simulate an interrupt to force
3281 # us into the command loop
3283 } ## end if ($single and not $second_time...
3285 # If we're in single-step mode, or an interrupt (real or fake)
3286 # has occurred, turn off non-stop mode.
3287 $runnonstop = 0 if $single or $signal;
3292 sub _my_print_lineinfo
3294 my ($self, $i, $incr_pos) = @_;
3297 # Print it indented if tracing is on.
3298 DB::print_lineinfo( ' ' x $stack_depth,
3299 "$i:\t$DB::dbline[$i]" . $self->after );
3302 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3307 return $DB::dbline[$line];
3311 my ($self, $letter) = @_;
3313 return ($DB::cmd eq $letter);
3316 sub _DB__grab_control
3320 # Yes, grab control.
3321 if ($slave_editor) {
3323 # Tell the editor to update its position.
3324 $self->position("\032\032${DB::filename}:$line:0\n");
3325 DB::print_lineinfo($self->position());
3330 Special check: if we're in package C<DB::fake>, we've gone through the
3331 C<END> block at least once. We set up everything so that we can continue
3332 to enter commands and have a valid context to be in.
3336 elsif ( $DB::package eq 'DB::fake' ) {
3338 # Fallen off the end already.
3343 DB::print_help(<<EOP);
3344 Debugged program terminated. Use B<q> to quit or B<R> to restart,
3345 use B<o> I<inhibit_exit> to avoid stopping after program termination,
3346 B<h q>, B<h R> or B<h o> to get additional info.
3349 # Set the DB::eval context appropriately.
3350 # At program termination disable any user actions.
3351 $DB::action = undef;
3353 $DB::package = 'main';
3354 $DB::usercontext = DB::_calc_usercontext($DB::package);
3355 } ## end elsif ($package eq 'DB::fake')
3359 If the program hasn't finished executing, we scan forward to the
3360 next executable line, print that out, build the prompt from the file and line
3361 number information, and print that.
3368 # Still somewhere in the midst of execution. Set up the
3370 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3371 # Perl 5 ones (sorry, we don't print Klingon
3374 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
3375 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
3376 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
3378 # Break up the prompt if it's really long.
3379 if ( length($self->prefix()) > 30 ) {
3380 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
3382 $self->infix(":\t");
3385 $self->infix("):\t");
3387 $self->prefix . $line. $self->infix
3388 . $self->_curr_line . $self->after
3392 # Print current line info, indenting if necessary.
3393 $self->_my_print_lineinfo($line, $self->position);
3396 my $line_i = sub { return $DB::dbline[$i]; };
3398 # Scan forward, stopping at either the end or the next
3400 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
3403 # Drop out on null statements, block closers, and comments.
3404 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
3406 # Drop out if the user interrupted us.
3409 # Append a newline if the line doesn't have one. Can happen
3410 # in eval'ed text, for instance.
3411 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
3413 # Next executable line.
3414 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
3416 $self->append_to_position($incr_pos);
3417 $self->_my_print_lineinfo($i, $incr_pos);
3418 } ## end for ($i = $line + 1 ; $i...
3419 } ## end else [ if ($slave_editor)
3424 sub _handle_t_command {
3427 my $levels = $self->cmd_args();
3429 if ((!length($levels)) or ($levels !~ /\D/)) {
3432 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3433 print {$OUT} "Trace = "
3435 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3444 sub _handle_S_command {
3447 if (my ($print_all_subs, $should_reverse, $Spatt)
3448 = $self->cmd_args =~ /\A((!)?(.+))?\z/) {
3449 # $Spatt is the pattern (if any) to use.
3451 my $Srev = defined $should_reverse;
3452 # No args - print all subs.
3453 my $Snocheck = !defined $print_all_subs;
3455 # Need to make these sane here.
3459 # Search through the debugger's magical hash of subs.
3460 # If $nocheck is true, just print the sub name.
3461 # Otherwise, check it against the pattern. We then use
3462 # the XOR trick to reverse the condition as required.
3463 foreach $subname ( sort( keys %sub ) ) {
3464 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3465 print $OUT $subname, "\n";
3474 sub _handle_V_command_and_X_command {
3477 $DB::cmd =~ s/^X\b/V $DB::package/;
3479 # Bare V commands get the currently-being-debugged package
3481 if ($self->_is_full('V')) {
3482 $DB::cmd = "V $DB::package";
3485 # V - show variables in package.
3486 if (my ($new_packname, $new_vars_str) =
3487 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3489 # Save the currently selected filehandle and
3490 # force output to debugger's filehandle (dumpvar
3491 # just does "print" for output).
3492 my $savout = select($OUT);
3494 # Grab package name and variables to dump.
3495 $packname = $new_packname;
3496 my @vars = split( ' ', $new_vars_str );
3498 # If main::dumpvar isn't here, get it.
3499 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3500 if ( defined &main::dumpvar ) {
3502 # We got it. Turn off subroutine entry/exit messages
3503 # for the moment, along with return values.
3507 # must detect sigpipe failures - not catching
3508 # then will cause the debugger to die.
3512 defined $option{dumpDepth}
3513 ? $option{dumpDepth}
3514 : -1, # assume -1 unless specified
3519 # The die doesn't need to include the $@, because
3520 # it will automatically get propagated for us.
3522 die unless $@ =~ /dumpvar print failed/;
3524 } ## end if (defined &main::dumpvar)
3527 # Couldn't load dumpvar.
3528 print $OUT "dumpvar.pl not available.\n";
3531 # Restore the output filehandle, and go round again.
3539 sub _handle_dash_command {
3542 if ($self->_is_full('-')) {
3544 # back up by a window; go to 1 if back too far.
3545 $start -= $incr + $window + 1;
3546 $start = 1 if $start <= 0;
3547 $incr = $window - 1;
3549 # Generate and execute a "l +" command (handled below).
3550 $DB::cmd = 'l ' . ($start) . '+';
3556 sub _n_or_s_commands_generic {
3557 my ($self, $new_val) = @_;
3559 next CMD if DB::_DB__is_finished();
3561 # Single step, but don't enter subs.
3564 # Save for empty command (repeat last).
3565 $laststep = $DB::cmd;
3570 my ($self, $letter, $new_val) = @_;
3572 if ($self->_is_full($letter)) {
3573 $self->_n_or_s_commands_generic($new_val);
3576 $self->_n_or_s_and_arg_commands_generic($letter, $new_val);
3582 sub _handle_n_command {
3585 return $self->_n_or_s('n', 2);
3588 sub _handle_s_command {
3591 return $self->_n_or_s('s', 1);
3594 sub _handle_r_command {
3597 # r - return from the current subroutine.
3598 if ($self->_is_full('r')) {
3600 # Can't do anything if the program's over.
3601 next CMD if DB::_DB__is_finished();
3603 # Turn on stack trace.
3604 $stack[$stack_depth] |= 1;
3606 # Print return value unless the stack is empty.
3607 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3614 sub _handle_T_command {
3617 if ($self->_is_full('T')) {
3618 DB::print_trace( $OUT, 1 ); # skip DB
3625 sub _handle_w_command {
3628 DB::cmd_w( 'w', $self->cmd_args() );
3634 sub _handle_W_command {
3637 if (my $arg = $self->cmd_args) {
3638 DB::cmd_W( 'W', $arg );
3645 sub _handle_rc_recall_command {
3648 # $rc - recall command.
3649 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3651 # No arguments, take one thing off history.
3652 pop(@hist) if length($DB::cmd) > 1;
3654 # Relative (- found)?
3655 # Y - index back from most recent (by 1 if bare minus)
3656 # N - go to that particular command slot or the last
3657 # thing if nothing following.
3660 scalar($minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist ))
3663 # Pick out the command desired.
3664 $DB::cmd = $hist[$self->cmd_verb];
3666 # Print the command to be executed and restart the loop
3667 # with that command in the buffer.
3668 print {$OUT} $DB::cmd, "\n";
3675 sub _handle_rc_search_history_command {
3678 # $rc pattern $rc - find a command in the history.
3679 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) {
3681 # Create the pattern to use.
3685 # Toss off last entry if length is >1 (and it always is).
3686 pop(@hist) if length($DB::cmd) > 1;
3690 # Look backward through the history.
3692 for ( $i = $#hist ; $i ; --$i ) {
3693 # Stop if we find it.
3694 last SEARCH_HIST if $hist[$i] =~ /$pat/;
3700 print $OUT "No such command!\n\n";
3704 # Found it. Put it in the buffer, print it, and process it.
3705 $DB::cmd = $hist[$i];
3706 print $OUT $DB::cmd, "\n";
3713 sub _handle_H_command {
3716 if ($self->cmd_args =~ m#\A\*#) {
3717 @hist = @truehist = ();
3718 print $OUT "History cleansed\n";
3722 if (my ($num) = $self->cmd_args =~ /\A(?:-(\d+))?/) {
3724 # Anything other than negative numbers is ignored by
3725 # the (incorrect) pattern, so this test does nothing.
3726 $end = $num ? ( $#hist - $num ) : 0;
3728 # Set to the minimum if less than zero.
3729 $hist = 0 if $hist < 0;
3731 # Start at the end of the array.
3732 # Stay in while we're still above the ending value.
3733 # Tick back by one each time around the loop.
3736 for ( $i = $#hist ; $i > $end ; $i-- ) {
3738 # Print the command unless it has no arguments.
3739 print $OUT "$i: ", $hist[$i], "\n"
3740 unless $hist[$i] =~ /^.?$/;
3749 sub _handle_doc_command {
3752 # man, perldoc, doc - show manual pages.
3754 = $DB::cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
3755 DB::runman($man_page);
3762 sub _handle_p_command {
3765 my $print_cmd = 'print {$DB::OUT} ';
3766 # p - print (no args): print $_.
3767 if ($self->_is_full('p')) {
3768 $DB::cmd = $print_cmd . '$_';
3771 # p - print the given expression.
3772 $DB::cmd =~ s/\Ap\b/$print_cmd /;
3778 sub _handle_equal_sign_command {
3781 if ($DB::cmd =~ s/\A=\s*//) {
3783 if ( length $DB::cmd == 0 ) {
3785 # No args, get current aliases.
3786 @keys = sort keys %alias;
3788 elsif ( my ( $k, $v ) = ( $DB::cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3790 # Creating a new alias. $k is alias name, $v is
3793 # can't use $_ or kill //g state
3794 for my $x ( $k, $v ) {
3796 # Escape "alarm" characters.
3800 # Substitute key for value, using alarm chars
3801 # as separators (which is why we escaped them in
3803 $alias{$k} = "s\a$k\a$v\a";
3805 # Turn off standard warn and die behavior.
3806 local $SIG{__DIE__};
3807 local $SIG{__WARN__};
3810 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3812 # Nope. Bad alias. Say so and get out.
3813 print $OUT "Can't alias $k to $v: $@\n";
3818 # We'll only list the new one.
3820 } ## end elsif (my ($k, $v) = ($DB::cmd...
3822 # The argument is the alias to list.
3830 # Messy metaquoting: Trim the substitution code off.
3831 # We use control-G as the delimiter because it's not
3832 # likely to appear in the alias.
3833 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3836 print $OUT "$k\t= $1\n";
3838 elsif ( defined $alias{$k} ) {
3840 # Couldn't trim it off; just print the alias code.
3841 print $OUT "$k\t$alias{$k}\n";
3846 print "No alias for $k\n";
3848 } ## end for my $k (@keys)
3855 sub _handle_source_command {
3858 # source - read commands from a file (or pipe!) and execute.
3859 if (my $sourced_fn = $self->cmd_args) {
3860 if ( open my $fh, $sourced_fn ) {
3862 # Opened OK; stick it in the list of file handles.
3868 DB::_db_warn("Can't execute '$sourced_fn': $!\n");
3876 sub _handle_enable_disable_commands {
3879 my $which_cmd = $self->cmd_verb;
3880 my $position = $self->cmd_args;
3882 if ($position !~ /\s/) {
3883 my ($fn, $line_num);
3884 if ($position =~ m{\A\d+\z})
3886 $fn = $DB::filename;
3887 $line_num = $position;
3889 elsif (my ($new_fn, $new_line_num)
3890 = $position =~ m{\A(.*):(\d+)\z}) {
3891 ($fn, $line_num) = ($new_fn, $new_line_num);
3895 DB::_db_warn("Wrong spec for enable/disable argument.\n");
3899 if (DB::_has_breakpoint_data_ref($fn, $line_num)) {
3900 DB::_set_breakpoint_enabled_status($fn, $line_num,
3901 ($which_cmd eq 'enable' ? 1 : '')
3905 DB::_db_warn("No breakpoint set at ${fn}:${line_num}\n");
3915 sub _handle_save_command {
3918 if (my $new_fn = $self->cmd_args) {
3919 my $filename = $new_fn || '.perl5dbrc'; # default?
3920 if ( open my $fh, '>', $filename ) {
3922 # chomp to remove extraneous newlines from source'd files
3923 chomp( my @truelist =
3924 map { m/\A\s*(save|source)/ ? "#$_" : $_ }
3926 print {$fh} join( "\n", @truelist );
3927 print "commands saved in $filename\n";
3930 DB::_db_warn("Can't save debugger commands in '$new_fn': $!\n");
3938 sub _n_or_s_and_arg_commands_generic {
3939 my ($self, $letter, $new_val) = @_;
3941 # s - single-step. Remember the last command was 's'.
3942 if ($DB::cmd =~ s#\A\Q$letter\E\s#\$DB::single = $new_val;\n#) {
3943 $laststep = $letter;
3949 sub _handle_sh_command {
3952 # $sh$sh - run a shell command (if it's all ASCII).
3953 # Can't run shell commands with Unicode in the debugger, hmm.
3954 my $my_cmd = $DB::cmd;
3955 if ($my_cmd =~ m#\A$sh#gms) {
3957 if ($my_cmd =~ m#\G\z#cgms) {
3958 # Run the user's shell. If none defined, run Bourne.
3959 # We resume execution when the shell terminates.
3960 DB::_db_system( $ENV{SHELL} || "/bin/sh" );
3963 elsif ($my_cmd =~ m#\G$sh\s*(.*)#cgms) {
3968 elsif ($my_cmd =~ m#\G\s*(.*)#cgms) {
3969 DB::_db_system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3975 sub _handle_x_command {
3978 if ($DB::cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
3979 $onetimeDump = 'dump'; # main::dumpvar shows the output
3981 # handle special "x 3 blah" syntax XXX propagate
3982 # doc back to special variables.
3983 if ( $DB::cmd =~ s#\A\s*(\d+)(?=\s)# #) {
3984 $onetimedumpDepth = $1;
3991 sub _handle_q_command {
3994 if ($self->_is_full('q')) {
4003 sub _handle_cmd_wrapper_commands {
4006 DB::cmd_wrapper( $self->cmd_verb, $self->cmd_args, $line );
4010 sub _handle_special_char_cmd_wrapper_commands {
4013 # All of these commands were remapped in perl 5.8.0;
4014 # we send them off to the secondary dispatcher (see below).
4015 if (my ($cmd_letter, $my_arg) = $DB::cmd =~ /\A([<>\{]{1,2})\s*(.*)/so) {
4016 DB::cmd_wrapper( $cmd_letter, $my_arg, $line );
4027 # The following code may be executed now:
4032 C<sub> is called whenever a subroutine call happens in the program being
4033 debugged. The variable C<$DB::sub> contains the name of the subroutine
4036 The core function of this subroutine is to actually call the sub in the proper
4037 context, capturing its output. This of course causes C<DB::DB> to get called
4038 again, repeating until the subroutine ends and returns control to C<DB::sub>
4039 again. Once control returns, C<DB::sub> figures out whether or not to dump the
4040 return value, and returns its captured copy of the return value as its own
4041 return value. The value then feeds back into the program being debugged as if
4042 C<DB::sub> hadn't been there at all.
4044 C<sub> does all the work of printing the subroutine entry and exit messages
4045 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
4046 and also prints the return value if needed (for the C<r> command and if
4047 the 16 bit is set in C<$frame>).
4049 It also tracks the subroutine call depth by saving the current setting of
4050 C<$single> in the C<@stack> package global; if this exceeds the value in
4051 C<$deep>, C<sub> automatically turns on printing of the current depth by
4052 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
4053 of stop/don't stop on entry to subs set as it currently is set.
4055 =head3 C<caller()> support
4057 If C<caller()> is called from the package C<DB>, it provides some
4058 additional data, in the following order:
4064 The package name the sub was in
4066 =item * C<$filename>
4068 The filename it was defined in
4072 The line number it was defined on
4074 =item * C<$subroutine>
4076 The subroutine name; C<(eval)> if an C<eval>().
4080 1 if it has arguments, 0 if not
4082 =item * C<$wantarray>
4084 1 if array context, 0 if scalar context
4086 =item * C<$evaltext>
4088 The C<eval>() text, if any (undefined for C<eval BLOCK>)
4090 =item * C<$is_require>
4092 frame was created by a C<use> or C<require> statement
4096 pragma information; subject to change between versions
4100 pragma information; subject to change between versions
4102 =item * C<@DB::args>
4104 arguments with which the subroutine was invoked
4112 # We need to fully qualify the name ("DB::sub") to make "use strict;"
4113 # happy. -- Shlomi Fish
4115 sub _indent_print_line_info {
4116 my ($offset, $str) = @_;
4118 print_lineinfo( ' ' x ($stack_depth - $offset), $str);
4123 sub _print_frame_message {
4127 if ($frame & 4) { # Extended frame entry message
4128 _indent_print_line_info(-1, "in ");
4130 # Why -1? But it works! :-(
4131 # Because print_trace will call add 1 to it and then call
4132 # dump_trace; this results in our skipping -1+1 = 0 stack frames
4135 # Now it's 0 because we extracted a function.
4136 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" );
4139 _indent_print_line_info(-1, "entering $sub$al\n" );
4147 my ( $al, $ret, @ret ) = "";
4149 # We stack the stack pointer and then increment it to protect us
4150 # from a situation that might unwind a whole bunch of call frames
4151 # at once. Localizing the stack pointer means that it will automatically
4152 # unwind the same amount when multiple stack frames are unwound.
4153 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4156 # lock ourselves under threads
4157 # While lock() permits recursive locks, there's two cases where it's bad
4158 # that we keep a hold on the lock while we call the sub:
4159 # - during cloning, Package::CLONE might be called in the context of the new
4160 # thread, which will deadlock if we hold the lock across the threads::new call
4161 # - for any function that waits any significant time
4162 # This also deadlocks if the parent thread joins(), since holding the lock
4163 # will prevent any child threads passing this point.
4164 # So release the lock for the function call.
4167 # Whether or not the autoloader was running, a scalar to put the
4168 # sub's return value in (if needed), and an array to put the sub's
4169 # return value in (if needed).
4170 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
4171 print "creating new thread\n";
4174 # If the last ten characters are '::AUTOLOAD', note we've traced
4175 # into AUTOLOAD for $sub.
4176 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4178 $al = " for $$sub" if defined $$sub;
4182 $#stack = $stack_depth;
4184 # Save current single-step setting.
4185 $stack[-1] = $single;
4187 # Turn off all flags except single-stepping.
4190 # If we've gotten really deeply recursed, turn on the flag that will
4191 # make us stop with the 'deep recursion' message.
4192 $single |= 4 if $stack_depth == $deep;
4194 # If frame messages are on ...
4196 _print_frame_message($al);
4199 # Determine the sub's return type, and capture appropriately.
4202 # Called in array context. call sub and capture output.
4203 # DB::DB will recursively get control again if appropriate; we'll come
4204 # back here when the sub is finished.
4208 elsif ( defined wantarray ) {
4210 # Save the value if it's wanted at all.
4215 # Void return, explicitly.
4223 # Pop the single-step value back off the stack.
4224 $single |= $stack[ $stack_depth-- ];
4227 if ($frame & 4) { # Extended exit message
4228 _indent_print_line_info(0, "out ");
4229 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" );
4232 _indent_print_line_info(0, "exited $sub$al\n" );
4237 # Print the return info if we need to.
4238 if ( $doret eq $stack_depth or $frame & 16 ) {
4240 # Turn off output record separator.
4242 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4244 # Indent if we're printing because of $frame tracing.
4247 print {$fh} ' ' x $stack_depth;
4250 # Print the return value.
4251 print {$fh} "list context return from $sub:\n";
4252 dumpit( $fh, \@ret );
4254 # And don't print it again.
4256 } ## end if ($doret eq $stack_depth...
4257 # And we have to return the return value now.
4259 } ## end if (wantarray)
4262 # If we are supposed to show the return value... same as before.
4263 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
4265 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4266 print $fh ( ' ' x $stack_depth ) if $frame & 16;
4269 ? "scalar context return from $sub: "
4270 : "void context return from $sub\n"
4272 dumpit( $fh, $ret ) if defined wantarray;
4274 } ## end if ($doret eq $stack_depth...
4276 # Return the appropriate scalar value.
4278 } ## end else [ if (wantarray)
4284 # We stack the stack pointer and then increment it to protect us
4285 # from a situation that might unwind a whole bunch of call frames
4286 # at once. Localizing the stack pointer means that it will automatically
4287 # unwind the same amount when multiple stack frames are unwound.
4288 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4291 $#stack = $stack_depth;
4293 # Save current single-step setting.
4294 $stack[-1] = $single;
4296 # Turn off all flags except single-stepping.
4297 # Use local so the single-step value is popped back off the
4299 local $single = $single & 1;
4303 # lock ourselves under threads
4306 # Whether or not the autoloader was running, a scalar to put the
4307 # sub's return value in (if needed), and an array to put the sub's
4308 # return value in (if needed).
4309 my ( $al, $ret, @ret ) = "";
4310 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
4311 print "creating new thread\n";
4314 # If the last ten characters are C'::AUTOLOAD', note we've traced
4315 # into AUTOLOAD for $sub.
4316 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4320 # If we've gotten really deeply recursed, turn on the flag that will
4321 # make us stop with the 'deep recursion' message.
4322 $single |= 4 if $stack_depth == $deep;
4324 # If frame messages are on ...
4325 _print_frame_message($al);
4328 # call the original lvalue sub.
4332 # Abstracting common code from multiple places elsewhere:
4333 sub depth_print_lineinfo {
4334 my $always_print = shift;
4336 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth);
4339 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
4341 In Perl 5.8.0, there was a major realignment of the commands and what they did,
4342 Most of the changes were to systematize the command structure and to eliminate
4343 commands that threw away user input without checking.
4345 The following sections describe the code added to make it easy to support
4346 multiple command sets with conflicting command names. This section is a start
4347 at unifying all command processing to make it simpler to develop commands.
4349 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
4350 number, and C<$dbline> (the current line) as arguments.
4352 Support functions in this section which have multiple modes of failure C<die>
4353 on error; the rest simply return a false value.
4355 The user-interface functions (all of the C<cmd_*> functions) just output
4360 The C<%set> hash defines the mapping from command letter to subroutine
4363 C<%set> is a two-level hash, indexed by set name and then by command name.
4364 Note that trying to set the CommandSet to C<foobar> simply results in the
4365 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
4374 'A' => 'pre580_null',
4376 'B' => 'pre580_null',
4377 'd' => 'pre580_null',
4380 'M' => 'pre580_null',
4382 'o' => 'pre580_null',
4388 '<' => 'pre590_prepost',
4389 '<<' => 'pre590_prepost',
4390 '>' => 'pre590_prepost',
4391 '>>' => 'pre590_prepost',
4392 '{' => 'pre590_prepost',
4393 '{{' => 'pre590_prepost',
4397 my %breakpoints_data;
4399 sub _has_breakpoint_data_ref {
4400 my ($filename, $line) = @_;
4403 exists( $breakpoints_data{$filename} )
4405 exists( $breakpoints_data{$filename}{$line} )
4409 sub _get_breakpoint_data_ref {
4410 my ($filename, $line) = @_;
4412 return ($breakpoints_data{$filename}{$line} ||= +{});
4415 sub _delete_breakpoint_data_ref {
4416 my ($filename, $line) = @_;
4418 delete($breakpoints_data{$filename}{$line});
4419 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) {
4420 delete($breakpoints_data{$filename});
4426 sub _set_breakpoint_enabled_status {
4427 my ($filename, $line, $status) = @_;
4429 _get_breakpoint_data_ref($filename, $line)->{'enabled'} =
4436 sub _enable_breakpoint_temp_enabled_status {
4437 my ($filename, $line) = @_;
4439 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1;
4444 sub _cancel_breakpoint_temp_enabled_status {
4445 my ($filename, $line) = @_;
4447 my $ref = _get_breakpoint_data_ref($filename, $line);
4449 delete ($ref->{'temp_enabled'});
4452 _delete_breakpoint_data_ref($filename, $line);
4458 sub _is_breakpoint_enabled {
4459 my ($filename, $line) = @_;
4461 my $data_ref = _get_breakpoint_data_ref($filename, $line);
4462 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'});
4465 =head2 C<cmd_wrapper()> (API)
4467 C<cmd_wrapper()> allows the debugger to switch command sets
4468 depending on the value of the C<CommandSet> option.
4470 It tries to look up the command in the C<%set> package-level I<lexical>
4471 (which means external entities can't fiddle with it) and create the name of
4472 the sub to call based on the value found in the hash (if it's there). I<All>
4473 of the commands to be handled in a set have to be added to C<%set>; if they
4474 aren't found, the 5.8.0 equivalent is called (if there is one).
4476 This code uses symbolic references.
4483 my $dblineno = shift;
4485 # Assemble the command subroutine's name by looking up the
4486 # command set and command name in %set. If we can't find it,
4487 # default to the older version of the command.
4489 . ( $set{$CommandSet}{$cmd}
4490 || ( $cmd =~ /\A[<>{]+/o ? 'prepost' : $cmd ) );
4492 # Call the command subroutine, call it by name.
4493 return __PACKAGE__->can($call)->( $cmd, $line, $dblineno );
4494 } ## end sub cmd_wrapper
4496 =head3 C<cmd_a> (command)
4498 The C<a> command handles pre-execution actions. These are associated with a
4499 particular line, so they're stored in C<%dbline>. We default to the current
4500 line if none is specified.
4506 my $line = shift || ''; # [.|line] expr
4509 # If it's dot (here), or not all digits, use the current line.
4510 $line =~ s/\A\./$dbline/;
4512 # Should be a line number followed by an expression.
4513 if ( my ($lineno, $expr) = $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
4515 if (! length($lineno)) {
4519 # If we have an expression ...
4520 if ( length $expr ) {
4522 # ... but the line isn't breakable, complain.
4523 if ( $dbline[$lineno] == 0 ) {
4525 "Line $lineno($dbline[$lineno]) does not have an action?\n";
4529 # It's executable. Record that the line has an action.
4530 $had_breakpoints{$filename} |= 2;
4532 # Remove any action, temp breakpoint, etc.
4533 $dbline{$lineno} =~ s/\0[^\0]*//;
4535 # Add the action to the line.
4536 $dbline{$lineno} .= "\0" . action($expr);
4538 _set_breakpoint_enabled_status($filename, $lineno, 1);
4540 } ## end if (length $expr)
4541 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
4546 "Adding an action requires an optional lineno and an expression\n"
4551 =head3 C<cmd_A> (command)
4553 Delete actions. Similar to above, except the delete code is in a separate
4554 subroutine, C<delete_action>.
4560 my $line = shift || '';
4564 $line =~ s/^\./$dbline/;
4566 # Call delete_action with a null param to delete them all.
4567 # The '1' forces the eval to be true. It'll be false only
4568 # if delete_action blows up for some reason, in which case
4569 # we print $@ and get out.
4570 if ( $line eq '*' ) {
4571 if (! eval { _delete_all_actions(); 1 }) {
4577 # There's a real line number. Pass it to delete_action.
4578 # Error trapping is as above.
4579 elsif ( $line =~ /^(\S.*)/ ) {
4580 if (! eval { delete_action($1); 1 }) {
4586 # Swing and a miss. Bad syntax.
4589 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4593 =head3 C<delete_action> (API)
4595 C<delete_action> accepts either a line number or C<undef>. If a line number
4596 is specified, we check for the line being executable (if it's not, it
4597 couldn't have had an action). If it is, we just take the action off (this
4598 will get any kind of an action, including breakpoints).
4602 sub _remove_action_from_dbline {
4605 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4606 delete $dbline{$i} if $dbline{$i} eq '';
4611 sub _delete_all_actions {
4612 print {$OUT} "Deleting all actions...\n";
4614 for my $file ( keys %had_breakpoints ) {
4615 local *dbline = $main::{ '_<' . $file };
4618 for my $i (1 .. $max) {
4619 if ( defined $dbline{$i} ) {
4620 _remove_action_from_dbline($i);
4624 unless ( $had_breakpoints{$file} &= ~2 ) {
4625 delete $had_breakpoints{$file};
4635 if ( defined($i) ) {
4637 die "Line $i has no action .\n" if $dbline[$i] == 0;
4639 # Nuke whatever's there.
4640 _remove_action_from_dbline($i);
4643 _delete_all_actions();
4647 =head3 C<cmd_b> (command)
4649 Set breakpoints. Since breakpoints can be set in so many places, in so many
4650 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4651 we try to parse the command type, and then shuttle it off to an appropriate
4652 subroutine to actually do the work of setting the breakpoint in the right
4659 my $line = shift; # [.|line] [cond]
4662 my $default_cond = sub {
4664 return length($cond) ? $cond : '1';
4667 # Make . the current line number if it's there..
4668 $line =~ s/^\.(\s|\z)/$dbline$1/;
4670 # No line number, no condition. Simple break on current line.
4671 if ( $line =~ /^\s*$/ ) {
4672 cmd_b_line( $dbline, 1 );
4675 # Break on load for a file.
4676 elsif ( my ($file) = $line =~ /^load\b\s*(.*)/ ) {
4681 # b compile|postpone <some sub> [<condition>]
4682 # The interpreter actually traps this one for us; we just put the
4683 # necessary condition in the %postponed hash.
4684 elsif ( my ($action, $subname, $cond)
4685 = $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4687 # De-Perl4-ify the name - ' separators to ::.
4688 $subname =~ s/'/::/g;
4690 # Qualify it into the current package unless it's already qualified.
4691 $subname = "${package}::" . $subname unless $subname =~ /::/;
4693 # Add main if it starts with ::.
4694 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4696 # Save the break type for this sub.
4697 $postponed{$subname} = (($action eq 'postpone')
4698 ? ( "break +0 if " . $default_cond->($cond) )
4700 } ## end elsif ($line =~ ...
4701 # b <filename>:<line> [<condition>]
4702 elsif (my ($filename, $line_num, $cond)
4703 = $line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) {
4704 cmd_b_filename_line(
4707 (length($cond) ? $cond : '1'),
4710 # b <sub name> [<condition>]
4711 elsif ( my ($new_subname, $new_cond) =
4712 $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4715 $subname = $new_subname;
4716 cmd_b_sub( $subname, $default_cond->($new_cond) );
4719 # b <line> [<condition>].
4720 elsif ( my ($line_n, $cond) = $line =~ /^(\d*)\s*(.*)/ ) {
4722 # Capture the line. If none, it's the current line.
4723 $line = $line_n || $dbline;
4726 cmd_b_line( $line, $default_cond->($cond) );
4729 # Line didn't make sense.
4731 print "confused by line($line)?\n";
4737 =head3 C<break_on_load> (API)
4739 We want to break when this file is loaded. Mark this file in the
4740 C<%break_on_load> hash, and note that it has a breakpoint in
4741 C<%had_breakpoints>.
4747 $break_on_load{$file} = 1;
4748 $had_breakpoints{$file} |= 1;
4751 =head3 C<report_break_on_load> (API)
4753 Gives us an array of filenames that are set to break on load. Note that
4754 only files with break-on-load are in here, so simply showing the keys
4759 sub report_break_on_load {
4760 sort keys %break_on_load;
4763 =head3 C<cmd_b_load> (command)
4765 We take the file passed in and try to find it in C<%INC> (which maps modules
4766 to files they came from). We mark those files for break-on-load via
4767 C<break_on_load> and then report that it was done.
4775 # This is a block because that way we can use a redo inside it
4776 # even without there being any looping structure at all outside it.
4779 # Save short name and full path if found.
4781 push @files, $::INC{$file} if $::INC{$file};
4783 # Tack on .pm and do it again unless there was a '.' in the name
4785 $file .= '.pm', redo unless $file =~ /\./;
4788 # Do the real work here.
4789 break_on_load($_) for @files;
4791 # All the files that have break-on-load breakpoints.
4792 @files = report_break_on_load;
4794 # Normalize for the purposes of our printing this.
4797 print $OUT "Will stop on load of '@files'.\n";
4798 } ## end sub cmd_b_load
4800 =head3 C<$filename_error> (API package global)
4802 Several of the functions we need to implement in the API need to work both
4803 on the current file and on other files. We don't want to duplicate code, so
4804 C<$filename_error> is used to contain the name of the file that's being
4805 worked on (if it's not the current one).
4807 We can now build functions in pairs: the basic function works on the current
4808 file, and uses C<$filename_error> as part of its error message. Since this is
4809 initialized to C<"">, no filename will appear when we are working on the
4812 The second function is a wrapper which does the following:
4818 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4822 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4826 Calls the first function.
4828 The first function works on the I<current> file (i.e., the one we changed to),
4829 and prints C<$filename_error> in the error message (the name of the other file)
4830 if it needs to. When the functions return, C<*dbline> is restored to point
4831 to the actual current file (the one we're executing in) and
4832 C<$filename_error> is restored to C<"">. This restores everything to
4833 the way it was before the second function was called at all.
4835 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4842 use vars qw($filename_error);
4843 $filename_error = '';
4845 =head3 breakable_line(from, to) (API)
4847 The subroutine decides whether or not a line in the current file is breakable.
4848 It walks through C<@dbline> within the range of lines specified, looking for
4849 the first line that is breakable.
4851 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4852 first line I<after> C<$to> that's breakable, if there is one.
4854 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4855 first line I<before> C<$to> that's breakable, if there is one.
4859 sub breakable_line {
4861 my ( $from, $to ) = @_;
4863 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4866 # If there are at least 2 arguments, we're trying to search a range.
4869 # $delta is positive for a forward search, negative for a backward one.
4870 my $delta = $from < $to ? +1 : -1;
4872 # Keep us from running off the ends of the file.
4873 my $limit = $delta > 0 ? $#dbline : 1;
4875 # Clever test. If you're a mathematician, it's obvious why this
4876 # test works. If not:
4877 # If $delta is positive (going forward), $limit will be $#dbline.
4878 # If $to is less than $limit, ($limit - $to) will be positive, times
4879 # $delta of 1 (positive), so the result is > 0 and we should use $to
4880 # as the stopping point.
4882 # If $to is greater than $limit, ($limit - $to) is negative,
4883 # times $delta of 1 (positive), so the result is < 0 and we should
4884 # use $limit ($#dbline) as the stopping point.
4886 # If $delta is negative (going backward), $limit will be 1.
4887 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4888 # (negative) so the result is > 0, and we use $to as the stopping
4891 # If $to is less than zero, ($limit - $to) will be positive,
4892 # times $delta of -1 (negative), so the result is not > 0, and
4893 # we use $limit (1) as the stopping point.
4895 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4896 # (negative), still giving zero; the result is not > 0, and
4897 # we use $limit (1) as the stopping point.
4899 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4900 # (negative), giving a positive (>0) value, so we'll set $limit to
4903 $limit = $to if ( $limit - $to ) * $delta > 0;
4905 # The real search loop.
4906 # $i starts at $from (the point we want to start searching from).
4907 # We move through @dbline in the appropriate direction (determined
4908 # by $delta: either -1 (back) or +1 (ahead).
4909 # We stay in as long as we haven't hit an executable line
4910 # ($dbline[$i] == 0 means not executable) and we haven't reached
4911 # the limit yet (test similar to the above).
4912 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4914 } ## end if (@_ >= 2)
4916 # If $i points to a line that is executable, return that.
4917 return $i unless $dbline[$i] == 0;
4919 # Format the message and print it: no breakable lines in range.
4920 my ( $pl, $upto ) = ( '', '' );
4921 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4923 # If there's a filename in filename_error, we'll see it.
4925 die "Line$pl $from$upto$filename_error not breakable\n";
4926 } ## end sub breakable_line
4928 =head3 breakable_line_in_filename(file, from, to) (API)
4930 Like C<breakable_line>, but look in another file.
4934 sub breakable_line_in_filename {
4936 # Capture the file name.
4939 # Swap the magic line array over there temporarily.
4940 local *dbline = $main::{ '_<' . $f };
4942 # If there's an error, it's in this other file.
4943 local $filename_error = " of '$f'";
4945 # Find the breakable line.
4948 # *dbline and $filename_error get restored when this block ends.
4950 } ## end sub breakable_line_in_filename
4952 =head3 break_on_line(lineno, [condition]) (API)
4954 Adds a breakpoint with the specified condition (or 1 if no condition was
4955 specified) to the specified line. Dies if it can't.
4961 my $cond = @_ ? shift(@_) : 1;
4967 # Woops, not a breakable line. $filename_error allows us to say
4968 # if it was in a different file.
4969 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4971 # Mark this file as having breakpoints in it.
4972 $had_breakpoints{$filename} |= 1;
4974 # If there is an action or condition here already ...
4975 if ( $dbline{$i} ) {
4977 # ... swap this condition for the existing one.
4978 $dbline{$i} =~ s/^[^\0]*/$cond/;
4982 # Nothing here - just add the condition.
4983 $dbline{$i} = $cond;
4985 _set_breakpoint_enabled_status($filename, $i, 1);
4989 } ## end sub break_on_line
4991 =head3 cmd_b_line(line, [condition]) (command)
4993 Wrapper for C<break_on_line>. Prints the failure message if it
4999 if (not eval { break_on_line(@_); 1 }) {
5001 print $OUT $@ and return;
5005 } ## end sub cmd_b_line
5007 =head3 cmd_b_filename_line(line, [condition]) (command)
5009 Wrapper for C<break_on_filename_line>. Prints the failure message if it
5014 sub cmd_b_filename_line {
5015 if (not eval { break_on_filename_line(@_); 1 }) {
5017 print $OUT $@ and return;
5023 =head3 break_on_filename_line(file, line, [condition]) (API)
5025 Switches to the file specified and then calls C<break_on_line> to set
5030 sub break_on_filename_line {
5033 my $cond = @_ ? shift(@_) : 1;
5035 # Switch the magical hash temporarily.
5036 local *dbline = $main::{ '_<' . $f };
5038 # Localize the variables that break_on_line uses to make its message.
5039 local $filename_error = " of '$f'";
5040 local $filename = $f;
5042 # Add the breakpoint.
5043 break_on_line( $i, $cond );
5046 } ## end sub break_on_filename_line
5048 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
5050 Switch to another file, search the range of lines specified for an
5051 executable one, and put a breakpoint on the first one you find.
5055 sub break_on_filename_line_range {
5059 my $cond = @_ ? shift(@_) : 1;
5061 # Find a breakable line if there is one.
5062 my $i = breakable_line_in_filename( $f, $from, $to );
5064 # Add the breakpoint.
5065 break_on_filename_line( $f, $i, $cond );
5068 } ## end sub break_on_filename_line_range
5070 =head3 subroutine_filename_lines(subname, [condition]) (API)
5072 Search for a subroutine within a given file. The condition is ignored.
5073 Uses C<find_sub> to locate the desired subroutine.
5077 sub subroutine_filename_lines {
5078 my ( $subname ) = @_;
5080 # Returned value from find_sub() is fullpathname:startline-endline.
5081 # The match creates the list (fullpathname, start, end).
5082 return (find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/);
5083 } ## end sub subroutine_filename_lines
5085 =head3 break_subroutine(subname) (API)
5087 Places a break on the first line possible in the specified subroutine. Uses
5088 C<subroutine_filename_lines> to find the subroutine, and
5089 C<break_on_filename_line_range> to place the break.
5093 sub break_subroutine {
5094 my $subname = shift;
5096 # Get filename, start, and end.
5097 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
5098 or die "Subroutine $subname not found.\n";
5101 # Null condition changes to '1' (always true).
5102 my $cond = @_ ? shift(@_) : 1;
5104 # Put a break the first place possible in the range of lines
5105 # that make up this subroutine.
5106 break_on_filename_line_range( $file, $s, $e, $cond );
5109 } ## end sub break_subroutine
5111 =head3 cmd_b_sub(subname, [condition]) (command)
5113 We take the incoming subroutine name and fully-qualify it as best we can.
5117 =item 1. If it's already fully-qualified, leave it alone.
5119 =item 2. Try putting it in the current package.
5121 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
5123 =item 4. If it starts with '::', put it in 'main::'.
5127 After all this cleanup, we call C<break_subroutine> to try to set the
5133 my $subname = shift;
5134 my $cond = @_ ? shift : 1;
5136 # If the subname isn't a code reference, qualify it so that
5137 # break_subroutine() will work right.
5138 if ( ref($subname) ne 'CODE' ) {
5141 $subname =~ s/'/::/g;
5144 # Put it in this package unless it's already qualified.
5145 if ($subname !~ /::/)
5147 $subname = $package . '::' . $subname;
5150 # Requalify it into CORE::GLOBAL if qualifying it into this
5151 # package resulted in its not being defined, but only do so
5152 # if it really is in CORE::GLOBAL.
5153 my $core_name = "CORE::GLOBAL::$s";
5154 if ((!defined(&$subname))
5156 and (defined &{$core_name}))
5158 $subname = $core_name;
5161 # Put it in package 'main' if it has a leading ::.
5162 if ($subname =~ /\A::/)
5164 $subname = "main" . $subname;
5166 } ## end if ( ref($subname) ne 'CODE' ) {
5168 # Try to set the breakpoint.
5169 if (not eval { break_subroutine( $subname, $cond ); 1 }) {
5176 } ## end sub cmd_b_sub
5178 =head3 C<cmd_B> - delete breakpoint(s) (command)
5180 The command mostly parses the command line and tries to turn the argument
5181 into a line spec. If it can't, it uses the current line. It then calls
5182 C<delete_breakpoint> to actually do the work.
5184 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
5185 thereby deleting all the breakpoints.
5192 # No line spec? Use dbline.
5193 # If there is one, use it if it's non-zero, or wipe it out if it is.
5194 my $line = ( $_[0] =~ /\A\./ ) ? $dbline : (shift || '');
5197 # If the line was dot, make the line the current one.
5198 $line =~ s/^\./$dbline/;
5200 # If it's * we're deleting all the breakpoints.
5201 if ( $line eq '*' ) {
5202 if (not eval { delete_breakpoint(); 1 }) {
5207 # If there is a line spec, delete the breakpoint on that line.
5208 elsif ( $line =~ /\A(\S.*)/ ) {
5209 if (not eval { delete_breakpoint( $line || $dbline ); 1 }) {
5213 } ## end elsif ($line =~ /^(\S.*)/)
5218 "Deleting a breakpoint requires a line number, or '*' for all\n"
5225 =head3 delete_breakpoint([line]) (API)
5227 This actually does the work of deleting either a single breakpoint, or all
5230 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
5231 just drop out with a message saying so. If it is, we remove the condition
5232 part of the 'condition\0action' that says there's a breakpoint here. If,
5233 after we've done that, there's nothing left, we delete the corresponding
5234 line in C<%dbline> to signal that no action needs to be taken for this line.
5236 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
5237 which lists all currently-loaded files which have breakpoints. We then look
5238 at each line in each of these files, temporarily switching the C<%dbline>
5239 and C<@dbline> structures to point to the files in question, and do what
5240 we did in the single line case: delete the condition in C<@dbline>, and
5241 delete the key in C<%dbline> if nothing's left.
5243 We then wholesale delete C<%postponed>, C<%postponed_file>, and
5244 C<%break_on_load>, because these structures contain breakpoints for files
5245 and code that haven't been loaded yet. We can just kill these off because there
5246 are no magical debugger structures associated with them.
5250 sub _remove_breakpoint_entry {
5254 _delete_breakpoint_data_ref($fn, $i);
5259 sub _delete_all_breakpoints {
5260 print {$OUT} "Deleting all breakpoints...\n";
5262 # %had_breakpoints lists every file that had at least one
5264 for my $fn ( keys %had_breakpoints ) {
5266 # Switch to the desired file temporarily.
5267 local *dbline = $main::{ '_<' . $fn };
5271 # For all lines in this file ...
5272 for my $i (1 .. $max) {
5274 # If there's a breakpoint or action on this line ...
5275 if ( defined $dbline{$i} ) {
5277 # ... remove the breakpoint.
5278 $dbline{$i} =~ s/\A[^\0]+//;
5279 if ( $dbline{$i} =~ s/\A\0?\z// ) {
5280 # Remove the entry altogether if no action is there.
5281 _remove_breakpoint_entry($fn, $i);
5283 } ## end if (defined $dbline{$i...
5284 } ## end for $i (1 .. $max)
5286 # If, after we turn off the "there were breakpoints in this file"
5287 # bit, the entry in %had_breakpoints for this file is zero,
5288 # we should remove this file from the hash.
5289 if ( not $had_breakpoints{$fn} &= (~1) ) {
5290 delete $had_breakpoints{$fn};
5292 } ## end for my $fn (keys %had_breakpoints)
5294 # Kill off all the other breakpoints that are waiting for files that
5295 # haven't been loaded yet.
5297 undef %postponed_file;
5298 undef %break_on_load;
5303 sub _delete_breakpoint_from_line {
5306 # Woops. This line wasn't breakable at all.
5307 die "Line $i not breakable.\n" if $dbline[$i] == 0;
5309 # Kill the condition, but leave any action.
5310 $dbline{$i} =~ s/\A[^\0]*//;
5312 # Remove the entry entirely if there's no action left.
5313 if ($dbline{$i} eq '') {
5314 _remove_breakpoint_entry($filename, $i);
5320 sub delete_breakpoint {
5323 # If we got a line, delete just that one.
5324 if ( defined($i) ) {
5325 _delete_breakpoint_from_line($i);
5327 # No line; delete them all.
5329 _delete_all_breakpoints();
5335 =head3 cmd_stop (command)
5337 This is meant to be part of the new command API, but it isn't called or used
5338 anywhere else in the debugger. XXX It is probably meant for use in development
5343 sub cmd_stop { # As on ^C, but not signal-safy.
5347 =head3 C<cmd_e> - threads
5349 Display the current thread id:
5353 This could be how (when implemented) to send commands to this thread id (e cmd)
5354 or that thread id (e tid cmd).
5361 unless (exists($INC{'threads.pm'})) {
5362 print "threads not loaded($ENV{PERL5DB_THREADED})
5363 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5365 my $tid = threads->tid;
5366 print "thread id: $tid\n";
5370 =head3 C<cmd_E> - list of thread ids
5372 Display the list of available thread ids:
5376 This could be used (when implemented) to send commands to all threads (E cmd).
5383 unless (exists($INC{'threads.pm'})) {
5384 print "threads not loaded($ENV{PERL5DB_THREADED})
5385 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5387 my $tid = threads->tid;
5388 print "thread ids: ".join(', ',
5389 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
5394 =head3 C<cmd_h> - help command (command)
5396 Does the work of either
5402 Showing all the debugger help
5406 Showing help for a specific command
5413 use vars qw($summary);
5418 # If we have no operand, assume null.
5419 my $line = shift || '';
5421 # 'h h'. Print the long-format help.
5422 if ( $line =~ /\Ah\s*\z/ ) {
5426 # 'h <something>'. Search for the command and print only its help.
5427 elsif ( my ($asked) = $line =~ /\A(\S.*)\z/ ) {
5429 # support long commands; otherwise bogus errors
5430 # happen when you ask for h on <CR> for example
5431 my $qasked = quotemeta($asked); # for searching; we don't
5432 # want to use it as a pattern.
5433 # XXX: finds CR but not <CR>
5435 # Search the help string for the command.
5437 $help =~ /^ # Start of a line
5439 (?:[IB]<) # Optional markup
5440 $qasked # The requested command
5445 # It's there; pull it out and print it.
5449 (?:[IB]<) # Optional markup
5450 $qasked # The command
5451 ([\s\S]*?) # Description line(s)
5452 \n) # End of last description line
5453 (?!\s) # Next line not starting with
5462 # Not found; not a debugger command.
5464 print_help("B<$asked> is not a debugger command.\n");
5466 } ## end elsif ($line =~ /^(\S.*)$/)
5468 # 'h' - print the summary help.
5470 print_help($summary);
5474 =head3 C<cmd_i> - inheritance display
5476 Display the (nested) parentage of the module or object given.
5483 foreach my $isa ( split( /\s+/, $line ) ) {
5485 # The &-call is here to ascertain the mutability of @_.
5493 defined( ${"$_\::VERSION"} )
5494 ? ' ' . ${"$_\::VERSION"}
5496 } @{mro::get_linear_isa(ref($isa) || $isa)}
5502 =head3 C<cmd_l> - list lines (command)
5504 Most of the command is taken up with transforming all the different line
5505 specification syntaxes into 'start-stop'. After that is done, the command
5506 runs a loop over C<@dbline> for the specified range of lines. It handles
5507 the printing of each line and any markers (C<==E<gt>> for current line,
5508 C<b> for break on this line, C<a> for action on this line, C<:> for this
5511 We save the last line listed in the C<$start> global for further listing
5518 foreach my $v (@_) {
5528 foreach my $v (@_) {
5536 sub _minify_to_max {
5539 $$ref = _min($$ref, $max);
5544 sub _cmd_l_handle_var_name {
5545 my $var_name = shift;
5547 $evalarg = $var_name;
5549 my ($s) = DB::eval();
5551 # Ooops. Bad scalar.
5553 print {$OUT} "Error: $@\n";
5557 # Good scalar. If it's a reference, find what it points to.
5559 print {$OUT} "Interpreted as: $1 $s\n";
5562 # Call self recursively to really do the command.
5563 return _cmd_l_main( $s );
5566 sub _cmd_l_handle_subname {
5571 $subname =~ s/\'/::/;
5573 # Put it in this package unless it starts with ::.
5574 $subname = $package . "::" . $subname unless $subname =~ /::/;
5576 # Put it in CORE::GLOBAL if t doesn't start with :: and
5577 # it doesn't live in this package and it lives in CORE::GLOBAL.
5578 $subname = "CORE::GLOBAL::$s"
5579 if not defined &$subname
5581 and defined &{"CORE::GLOBAL::$s"};
5583 # Put leading '::' names into 'main::'.
5584 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
5586 # Get name:start-stop from find_sub, and break this up at
5588 my @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
5590 # Pull off start-stop.
5591 my $subrange = pop @pieces;
5593 # If the name contained colons, the split broke it up.
5594 # Put it back together.
5595 $file = join( ':', @pieces );
5597 # If we're not in that file, switch over to it.
5598 if ( $file ne $filename ) {
5599 if (! $slave_editor) {
5600 print {$OUT} "Switching to file '$file'.\n";
5603 # Switch debugger's magic structures.
5604 *dbline = $main::{ '_<' . $file };
5607 } ## end if ($file ne $filename)
5609 # Subrange is 'start-stop'. If this is less than a window full,
5610 # swap it to 'start+', which will list a window from the start point.
5612 if ( eval($subrange) < -$window ) {
5613 $subrange =~ s/-.*/+/;
5616 # Call self recursively to list the range.
5617 return _cmd_l_main( $subrange );
5618 } ## end if ($subrange)
5622 print {$OUT} "Subroutine $subname not found.\n";
5628 # Compute new range to list.
5629 $incr = $window - 1;
5632 return _cmd_l_main( $start . '-' . ( $start + $incr ) );
5636 my ($new_start, $new_incr) = @_;
5638 # Don't reset start for 'l +nnn'.
5639 $start = $new_start if $new_start;
5641 # Increment for list. Use window size if not specified.
5642 # (Allows 'l +' to work.)
5643 $incr = $new_incr || ($window - 1);
5645 # Create a line range we'll understand, and recurse to do it.
5646 return _cmd_l_main( $start . '-' . ( $start + $incr ) );
5649 sub _cmd_l_calc_initial_end_and_i {
5650 my ($spec, $start_match, $end_match) = @_;
5652 # Determine end point; use end of file if not specified.
5653 my $end = ( !defined $start_match ) ? $max :
5654 ( $end_match ? $end_match : $start_match );
5656 # Go on to the end, and then stop.
5657 _minify_to_max(\$end);
5659 # Determine start line.
5660 my $i = $start_match;
5674 my ($spec, $current_line, $start_match, $end_match) = @_;
5677 _cmd_l_calc_initial_end_and_i($spec, $start_match, $end_match);
5679 # If we're running under a slave editor, force it to show the lines.
5680 if ($slave_editor) {
5681 print {$OUT} "\032\032$filename:$i:0\n";
5684 # We're doing it ourselves. We want to show the line and special
5686 # - the current line in execution
5687 # - whether a line is breakable or not
5688 # - whether a line has a break or not
5689 # - whether a line has an action or not
5692 for ( ; $i <= $end ; $i++ ) {
5694 # Check for breakpoints and actions.
5695 my ( $stop, $action );
5697 ( $stop, $action ) = split( /\0/, $dbline{$i} );
5700 # ==> if this is the current line in execution,
5701 # : if it's breakable.
5703 ( $i == $current_line and $filename eq $filename_ini )
5705 : ( $dbline[$i] + 0 ? ':' : ' ' );
5707 # Add break and action indicators.
5708 $arrow .= 'b' if $stop;
5709 $arrow .= 'a' if $action;
5712 print {$OUT} "$i$arrow\t", $dbline[$i];
5714 # Move on to the next line. Drop out on an interrupt.
5719 } ## end for (; $i <= $end ; $i++)
5721 # Line the prompt up; print a newline if the last line listed
5722 # didn't have a newline.
5723 if ($dbline[ $i - 1 ] !~ /\n\z/) {
5726 } ## end else [ if ($slave_editor)
5728 # Save the point we last listed to in case another relative 'l'
5729 # command is desired. Don't let it run off the end.
5731 _minify_to_max(\$start);
5739 # If this is '-something', delete any spaces after the dash.
5740 $spec =~ s/\A-\s*\z/-/;
5742 # If the line is '$something', assume this is a scalar containing a
5744 # Set up for DB::eval() - evaluate in *user* context.
5745 if ( my ($var_name) = $spec =~ /\A(\$.*)/s ) {
5746 return _cmd_l_handle_var_name($var_name);
5748 # l name. Try to find a sub by that name.
5749 elsif ( ($subname) = $spec =~ /\A([\':A-Za-z_][\':\w]*(?:\[.*\])?)/s ) {
5750 return _cmd_l_handle_subname();
5753 elsif ( $spec !~ /\S/ ) {
5754 return _cmd_l_empty();
5756 # l [start]+number_of_lines
5757 elsif ( my ($new_start, $new_incr) = $spec =~ /\A(\d*)\+(\d*)\z/ ) {
5758 return _cmd_l_plus($new_start, $new_incr);
5760 # l start-stop or l start,stop
5761 elsif (my ($s, $e) = $spec =~ /^(?:(-?[\d\$\.]+)(?:[-,]([\d\$\.]+))?)?/ ) {
5762 return _cmd_l_range($spec, $line, $s, $e);
5769 my (undef, $line) = @_;
5771 return _cmd_l_main($line);
5774 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5776 To list breakpoints, the command has to look determine where all of them are
5777 first. It starts a C<%had_breakpoints>, which tells us what all files have
5778 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5779 magic source and breakpoint data structures) to the file, and then look
5780 through C<%dbline> for lines with breakpoints and/or actions, listing them
5781 out. We look through C<%postponed> not-yet-compiled subroutines that have
5782 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5783 that have breakpoints.
5785 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5789 sub _cmd_L_calc_arg {
5790 # If no argument, list everything. Pre-5.8.0 version always lists
5792 my $arg = shift || 'abw';
5793 if ($CommandSet ne '580')
5801 sub _cmd_L_calc_wanted_flags {
5802 my $arg = _cmd_L_calc_arg(shift);
5804 return (map { index($arg, $_) >= 0 ? 1 : 0 } qw(a b w));
5808 sub _cmd_L_handle_breakpoints {
5809 my ($handle_db_line) = @_;
5812 # Look in all the files with breakpoints...
5813 for my $file ( keys %had_breakpoints ) {
5815 # Temporary switch to this file.
5816 local *dbline = $main::{ '_<' . $file };
5818 # Set up to look through the whole file.
5820 my $was; # Flag: did we print something
5823 # For each line in the file ...
5824 for my $i (1 .. $max) {
5826 # We've got something on this line.
5827 if ( defined $dbline{$i} ) {
5829 # Print the header if we haven't.
5831 print {$OUT} "$file:\n";
5835 print {$OUT} " $i:\t", $dbline[$i];
5837 $handle_db_line->($dbline{$i});
5839 # Quit if the user hit interrupt.
5841 last BREAKPOINTS_SCAN;
5843 } ## end if (defined $dbline{$i...
5844 } ## end for my $i (1 .. $max)
5845 } ## end for my $file (keys %had_breakpoints)
5850 sub _cmd_L_handle_postponed_breakpoints {
5851 my ($handle_db_line) = @_;
5853 print {$OUT} "Postponed breakpoints in files:\n";
5856 for my $file ( keys %postponed_file ) {
5857 my $db = $postponed_file{$file};
5858 print {$OUT} " $file:\n";
5859 for my $line ( sort { $a <=> $b } keys %$db ) {
5860 print {$OUT} " $line:\n";
5862 $handle_db_line->($db->{$line});
5865 last POSTPONED_SCANS;
5869 last POSTPONED_SCANS;
5880 my ($action_wanted, $break_wanted, $watch_wanted) =
5881 _cmd_L_calc_wanted_flags(shift);
5883 my $handle_db_line = sub {
5886 my ( $stop, $action ) = split( /\0/, $l );
5888 if ($stop and $break_wanted) {
5889 print {$OUT} " break if (", $stop, ")\n"
5892 if ($action && $action_wanted) {
5893 print {$OUT} " action: ", $action, "\n"
5899 # Breaks and actions are found together, so we look in the same place
5901 if ( $break_wanted or $action_wanted ) {
5902 _cmd_L_handle_breakpoints($handle_db_line);
5905 # Look for breaks in not-yet-compiled subs:
5906 if ( %postponed and $break_wanted ) {
5907 print {$OUT} "Postponed breakpoints in subroutines:\n";
5910 for $subname ( keys %postponed ) {
5911 print {$OUT} " $subname\t$postponed{$subname}\n";
5916 } ## end if (%postponed and $break_wanted)
5918 # Find files that have not-yet-loaded breaks:
5919 my @have = map { # Combined keys
5920 keys %{ $postponed_file{$_} }
5921 } keys %postponed_file;
5923 # If there are any, list them.
5924 if ( @have and ( $break_wanted or $action_wanted ) ) {
5925 _cmd_L_handle_postponed_breakpoints($handle_db_line);
5926 } ## end if (@have and ($break_wanted...
5928 if ( %break_on_load and $break_wanted ) {
5929 print {$OUT} "Breakpoints on load:\n";
5930 BREAK_ON_LOAD: for my $filename ( keys %break_on_load ) {
5931 print {$OUT} " $filename\n";
5932 last BREAK_ON_LOAD if $signal;
5934 } ## end if (%break_on_load and...
5936 if ($watch_wanted and ( $trace & 2 )) {
5937 print {$OUT} "Watch-expressions:\n" if @to_watch;
5938 TO_WATCH: for my $expr (@to_watch) {
5939 print {$OUT} " $expr\n";
5940 last TO_WATCH if $signal;
5947 =head3 C<cmd_M> - list modules (command)
5949 Just call C<list_modules>.
5959 =head3 C<cmd_o> - options (command)
5961 If this is just C<o> by itself, we list the current settings via
5962 C<dump_option>. If there's a nonblank value following it, we pass that on to
5963 C<parse_options> for processing.
5969 my $opt = shift || ''; # opt[=val]
5971 # Nonblank. Try to parse and process.
5972 if ( $opt =~ /^(\S.*)/ ) {
5976 # Blank. List the current option settings.
5984 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5986 Advises the user that the O command has been renamed.
5991 print $OUT "The old O command is now the o command.\n"; # hint
5992 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5993 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5996 =head3 C<cmd_v> - view window (command)
5998 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5999 move back a few lines to list the selected line in context. Uses C<cmd_l>
6000 to do the actual listing after figuring out the range of line to request.
6004 use vars qw($preview);
6010 # Extract the line to list around. (Astute readers will have noted that
6011 # this pattern will match whether or not a numeric line is specified,
6012 # which means that we'll always enter this loop (though a non-numeric
6013 # argument results in no action at all)).
6014 if ( $line =~ /^(\d*)$/ ) {
6016 # Total number of lines to list (a windowful).
6017 $incr = $window - 1;
6019 # Set the start to the argument given (if there was one).
6022 # Back up by the context amount.
6025 # Put together a linespec that cmd_l will like.
6026 $line = $start . '-' . ( $start + $incr );
6029 cmd_l( 'l', $line );
6030 } ## end if ($line =~ /^(\d*)$/)
6033 =head3 C<cmd_w> - add a watch expression (command)
6035 The 5.8 version of this command adds a watch expression if one is specified;
6036 it does nothing if entered with no operands.
6038 We extract the expression, save it, evaluate it in the user's context, and
6039 save the value. We'll re-evaluate it each time the debugger passes a line,
6040 and will stop (see the code at the top of the command loop) if the value
6041 of any of the expressions changes.
6045 sub _add_watch_expr {
6049 push @to_watch, $expr;
6051 # Parameterize DB::eval and call it to get the expression's value
6052 # in the user's context. This version can handle expressions which
6053 # return a list value.
6055 # The &-call is here to ascertain the mutability of @_.
6056 my ($val) = join( ' ', &DB::eval);
6057 $val = ( defined $val ) ? "'$val'" : 'undef';
6059 # Save the current value of the expression.
6060 push @old_watch, $val;
6062 # We are now watching expressions.
6071 # Null expression if no arguments.
6072 my $expr = shift || '';
6074 # If expression is not null ...
6075 if ( $expr =~ /\A\S/ ) {
6076 _add_watch_expr($expr);
6077 } ## end if ($expr =~ /^(\S.*)/)
6079 # You have to give one to get one.
6081 print $OUT "Adding a watch-expression requires an expression\n"; # hint
6087 =head3 C<cmd_W> - delete watch expressions (command)
6089 This command accepts either a watch expression to be removed from the list
6090 of watch expressions, or C<*> to delete them all.
6092 If C<*> is specified, we simply empty the watch expression list and the
6093 watch expression value list. We also turn off the bit that says we've got
6096 If an expression (or partial expression) is specified, we pattern-match
6097 through the expressions and remove the ones that match. We also discard
6098 the corresponding values. If no watch expressions are left, we turn off
6099 the I<watching expressions> bit.
6105 my $expr = shift || '';
6108 if ( $expr eq '*' ) {
6113 print $OUT "Deleting all watch expressions ...\n";
6116 @to_watch = @old_watch = ();
6119 # Delete one of them.
6120 elsif ( $expr =~ /^(\S.*)/ ) {
6122 # Where we are in the list.
6125 # For each expression ...
6126 foreach (@to_watch) {
6127 my $val = $to_watch[$i_cnt];
6129 # Does this one match the command argument?
6130 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
6131 # Yes. Turn it off, and its value too.
6132 splice( @to_watch, $i_cnt, 1 );
6133 splice( @old_watch, $i_cnt, 1 );
6136 } ## end foreach (@to_watch)
6138 # We don't bother to turn watching off because
6139 # a) we don't want to stop calling watchfunction() if it exists
6140 # b) foreach over a null list doesn't do anything anyway
6142 } ## end elsif ($expr =~ /^(\S.*)/)
6144 # No command arguments entered.
6147 "Deleting a watch-expression requires an expression, or '*' for all\n"
6152 ### END of the API section
6154 =head1 SUPPORT ROUTINES
6156 These are general support routines that are used in a number of places
6157 throughout the debugger.
6161 save() saves the user's versions of globals that would mess us up in C<@saved>,
6162 and installs the versions we like better.
6168 # Save eval failure, command failure, extended OS error, output field
6169 # separator, input record separator, output record separator and
6170 # the warning setting.
6171 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
6173 $, = ""; # output field separator is null string
6174 $/ = "\n"; # input record separator is newline
6175 $\ = ""; # output record separator is null string
6176 $^W = 0; # warnings are off
6179 =head2 C<print_lineinfo> - show where we are now
6181 print_lineinfo prints whatever it is that it is handed; it prints it to the
6182 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
6183 us to feed line information to a slave editor without messing up the
6188 sub print_lineinfo {
6190 # Make the terminal sensible if we're not the primary debugger.
6191 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
6194 # $LINEINFO may be undef if $noTTY is set or some other issue.
6197 print {$LINEINFO} @_;
6199 } ## end sub print_lineinfo
6201 =head2 C<postponed_sub>
6203 Handles setting postponed breakpoints in subroutines once they're compiled.
6204 For breakpoints, we use C<DB::find_sub> to locate the source file and line
6205 range for the subroutine, then mark the file as having a breakpoint,
6206 temporarily switch the C<*dbline> glob over to the source file, and then
6207 search the given range of lines to find a breakable line. If we find one,
6208 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
6212 # The following takes its argument via $evalarg to preserve current @_
6216 # Get the subroutine name.
6217 my $subname = shift;
6219 # If this is a 'break +<n> if <condition>' ...
6220 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
6222 # If there's no offset, use '+0'.
6223 my $offset = $1 || 0;
6225 # find_sub's value is 'fullpath-filename:start-stop'. It's
6226 # possible that the filename might have colons in it too.
6227 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
6230 # We got the start line. Add the offset '+<n>' from
6231 # $postponed{subname}.
6234 # Switch to the file this sub is in, temporarily.
6235 local *dbline = $main::{ '_<' . $file };
6237 # No warnings, please.
6238 local $^W = 0; # != 0 is magical below
6240 # This file's got a breakpoint in it.
6241 $had_breakpoints{$file} |= 1;
6243 # Last line in file.
6246 # Search forward until we hit a breakable line or get to
6247 # the end of the file.
6248 ++$i until $dbline[$i] != 0 or $i >= $max;
6250 # Copy the breakpoint in and delete it from %postponed.
6251 $dbline{$i} = delete $postponed{$subname};
6254 # find_sub didn't find the sub.
6257 print $OUT "Subroutine $subname not found.\n";
6260 } ## end if ($postponed{$subname...
6261 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
6263 #print $OUT "In postponed_sub for '$subname'.\n";
6264 } ## end sub postponed_sub
6268 Called after each required file is compiled, but before it is executed;
6269 also called if the name of a just-compiled subroutine is a key of
6270 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
6271 etc.) into the just-compiled code.
6273 If this is a C<require>'d file, the incoming parameter is the glob
6274 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
6276 If it's a subroutine, the incoming parameter is the subroutine name.
6282 # If there's a break, process it.
6283 if ($ImmediateStop) {
6285 # Right, we've stopped. Turn it off.
6288 # Enter the command loop when DB::DB gets called.
6292 # If this is a subroutine, let postponed_sub() deal with it.
6293 if (ref(\$_[0]) ne 'GLOB') {
6294 return postponed_sub(@_);
6297 # Not a subroutine. Deal with the file.
6298 local *dbline = shift;
6299 my $filename = $dbline;
6300 $filename =~ s/^_<//;
6302 $signal = 1, print $OUT "'$filename' loaded...\n"
6303 if $break_on_load{$filename};
6304 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
6306 # Do we have any breakpoints to put in this file?
6307 return unless $postponed_file{$filename};
6309 # Yes. Mark this file as having breakpoints.
6310 $had_breakpoints{$filename} |= 1;
6312 # "Cannot be done: insufficient magic" - we can't just put the
6313 # breakpoints saved in %postponed_file into %dbline by assigning
6314 # the whole hash; we have to do it one item at a time for the
6315 # breakpoints to be set properly.
6316 #%dbline = %{$postponed_file{$filename}};
6318 # Set the breakpoints, one at a time.
6321 for $key ( keys %{ $postponed_file{$filename} } ) {
6323 # Stash the saved breakpoint into the current file's magic line array.
6324 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
6327 # This file's been compiled; discard the stored breakpoints.
6328 delete $postponed_file{$filename};
6330 } ## end sub postponed
6334 C<dumpit> is the debugger's wrapper around dumpvar.pl.
6336 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
6337 a reference to a variable (the thing to be dumped) as its input.
6339 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
6340 the currently-selected filehandle, thank you very much). The current
6341 values of the package globals C<$single> and C<$trace> are backed up in
6342 lexicals, and they are turned off (this keeps the debugger from trying
6343 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
6344 preserve its current value and it is set to zero to prevent entry/exit
6345 messages from printing, and C<$doret> is localized as well and set to -2 to
6346 prevent return values from being shown.
6348 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
6349 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
6350 installed version in C<@INC>, yours will be used instead. Possible security
6353 It then checks to see if the subroutine C<main::dumpValue> is now defined
6354 it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
6355 localizes the globals necessary for things to be sane when C<main::dumpValue()>
6356 is called, and picks up the variable to be dumped from the parameter list.
6358 It checks the package global C<%options> to see if there's a C<dumpDepth>
6359 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
6360 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
6361 structure: -1 means dump everything.
6363 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
6366 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
6367 and we then return to the caller.
6373 # Save the current output filehandle and switch to the one
6374 # passed in as the first parameter.
6375 my $savout = select(shift);
6377 # Save current settings of $single and $trace, and then turn them off.
6378 my $osingle = $single;
6379 my $otrace = $trace;
6380 $single = $trace = 0;
6382 # XXX Okay, what do $frame and $doret do, again?
6386 # Load dumpvar.pl unless we've already got the sub we need from it.
6387 unless ( defined &main::dumpValue ) {
6388 do 'dumpvar.pl' or die $@;
6391 # If the load succeeded (or we already had dumpvalue()), go ahead
6393 if ( defined &main::dumpValue ) {
6398 my $maxdepth = shift || $option{dumpDepth};
6399 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
6400 main::dumpValue( $v, $maxdepth );
6401 } ## end if (defined &main::dumpValue)
6403 # Oops, couldn't load dumpvar.pl.
6406 print $OUT "dumpvar.pl not available.\n";
6409 # Reset $single and $trace to their old values.
6413 # Restore the old filehandle.
6417 =head2 C<print_trace>
6419 C<print_trace>'s job is to print a stack trace. It does this via the
6420 C<dump_trace> routine, which actually does all the ferreting-out of the
6421 stack trace data. C<print_trace> takes care of formatting it nicely and
6422 printing it to the proper filehandle.
6430 The filehandle to print to.
6434 How many frames to skip before starting trace.
6438 How many frames to print.
6442 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
6446 The original comment below seems to be noting that the traceback may not be
6447 correct if this routine is called in a tied method.
6451 # Tied method do not create a context, so may get wrong message:
6457 # If this is going to a slave editor, but we're not the primary
6458 # debugger, reset it first.
6460 if $fh eq $LINEINFO # slave editor
6461 and $LINEINFO eq $OUT # normal output
6462 and $term_pid != $$; # not the primary
6464 # Collect the actual trace information to be formatted.
6465 # This is an array of hashes of subroutine call info.
6466 my @sub = dump_trace( $_[0] + 1, $_[1] );
6468 # Grab the "short report" flag from @_.
6469 my $short = $_[2]; # Print short report, next one for sub name
6471 # Run through the traceback info, format it, and print it.
6473 for my $i (0 .. $#sub) {
6475 # Drop out if the user has lost interest and hit control-C.
6478 # Set the separator so arrays print nice.
6481 # Grab and stringify the arguments if they are there.
6483 defined $sub[$i]{args}
6484 ? "(@{ $sub[$i]{args} })"
6487 # Shorten them up if $maxtrace says they're too long.
6488 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
6489 if length $args > $maxtrace;
6491 # Get the file name.
6492 my $file = $sub[$i]{file};
6494 # Put in a filename header if short is off.
6495 $file = $file eq '-e' ? $file : "file '$file'" unless $short;
6497 # Get the actual sub's name, and shorten to $maxtrace's requirement.
6498 $s = $sub[$i]{'sub'};
6499 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
6501 # Short report uses trimmed file and sub names.
6503 my $sub = @_ >= 4 ? $_[3] : $s;
6504 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
6505 } ## end if ($short)
6507 # Non-short report includes full names.
6509 print $fh "$sub[$i]{context} = $s$args"
6510 . " called from $file"
6511 . " line $sub[$i]{line}\n";
6513 } ## end for my $i (0 .. $#sub)
6514 } ## end sub print_trace
6516 =head2 dump_trace(skip[,count])
6518 Actually collect the traceback information available via C<caller()>. It does
6519 some filtering and cleanup of the data, but mostly it just collects it to
6520 make C<print_trace()>'s job easier.
6522 C<skip> defines the number of stack frames to be skipped, working backwards
6523 from the most current. C<count> determines the total number of frames to
6524 be returned; all of them (well, the first 10^9) are returned if C<count>
6527 This routine returns a list of hashes, from most-recent to least-recent
6528 stack frame. Each has the following keys and values:
6532 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
6534 =item * C<sub> - subroutine name, or C<eval> information
6536 =item * C<args> - undef, or a reference to an array of arguments
6538 =item * C<file> - the file in which this item was defined (if any)
6540 =item * C<line> - the line on which it was defined
6546 sub _dump_trace_calc_saved_single_arg
6548 my ($nothard, $arg) = @_;
6551 if ( not defined $arg ) { # undefined parameter
6555 elsif ( $nothard and tied $arg ) { # tied parameter
6558 elsif ( $nothard and $type = ref $arg ) { # reference
6559 return "ref($type)";
6561 else { # can be stringified
6563 "$arg"; # Safe to stringify now - should not call f().
6565 # Backslash any single-quotes or backslashes.
6568 # Single-quote it unless it's a number or a colon-separated
6571 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
6573 # Turn high-bit characters into meta-whatever, and controls into like
6575 require 'meta_notation.pm';
6576 $_ = _meta_notation($_) if /[[:^print:]]/a;
6582 sub _dump_trace_calc_save_args {
6586 map { _dump_trace_calc_saved_single_arg($nothard, $_) } @args
6592 # How many levels to skip.
6595 # How many levels to show. (1e9 is a cheap way of saying "all of them";
6596 # it's unlikely that we'll have more than a billion stack frames. If you
6597 # do, you've got an awfully big machine...)
6598 my $count = shift || 1e9;
6600 # We increment skip because caller(1) is the first level *back* from
6601 # the current one. Add $skip to the count of frames so we have a
6602 # simple stop criterion, counting from $skip to $count+$skip.
6606 # These variables are used to capture output from caller();
6607 my ( $p, $file, $line, $sub, $h, $context );
6609 my ( $e, $r, @sub, $args );
6611 # XXX Okay... why'd we do that?
6612 my $nothard = not $frame & 8;
6615 # Do not want to trace this.
6616 my $otrace = $trace;
6619 # Start out at the skip count.
6620 # If we haven't reached the number of frames requested, and caller() is
6621 # still returning something, stay in the loop. (If we pass the requested
6622 # number of stack frames, or we run out - caller() returns nothing - we
6624 # Up the stack frame index to go back one more level each time.
6628 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
6632 # if the sub has args ($h true), make an anonymous array of the
6634 my $args = $h ? _dump_trace_calc_save_args($nothard) : undef;
6636 # If context is true, this is array (@)context.
6637 # If context is false, this is scalar ($) context.
6638 # If neither, context isn't defined. (This is apparently a 'can't
6640 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
6642 # remove trailing newline-whitespace-semicolon-end of line sequence
6643 # from the eval text, if any.
6644 $e =~ s/\n\s*\;\s*\Z// if $e;
6646 # Escape backslashed single-quotes again if necessary.
6647 $e =~ s/([\\\'])/\\$1/g if $e;
6649 # if the require flag is true, the eval text is from a require.
6651 $sub = "require '$e'";
6654 # if it's false, the eval text is really from an eval.
6655 elsif ( defined $r ) {
6659 # If the sub is '(eval)', this is a block eval, meaning we don't
6660 # know what the eval'ed text actually was.
6661 elsif ( $sub eq '(eval)' ) {
6662 $sub = "eval {...}";
6665 # Stick the collected information into @sub as an anonymous hash.
6669 context => $context,
6677 # Stop processing frames if the user hit control-C.
6679 } ## end for ($i = $skip ; $i < ...
6681 # Restore the trace value again.
6684 } ## end sub dump_trace
6688 C<action()> takes input provided as the argument to an add-action command,
6689 either pre- or post-, and makes sure it's a complete command. It doesn't do
6690 any fancy parsing; it just keeps reading input until it gets a string
6691 without a trailing backslash.
6698 while ( $action =~ s/\\$// ) {
6700 # We have a backslash on the end. Read more.
6702 } ## end while ($action =~ s/\\$//)
6704 # Return the assembled action.
6710 This routine mostly just packages up a regular expression to be used
6711 to check that the thing it's being matched against has properly-matched
6714 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
6715 speeds things up by only creating the qr//'ed expression once; if it's
6716 already defined, we don't try to define it again. A speed hack.
6720 use vars qw($balanced_brace_re);
6724 # I hate using globals!
6725 $balanced_brace_re ||= qr{
6728 (?> [^{}] + ) # Non-parens without backtracking
6730 (??{ $balanced_brace_re }) # Group with matching parens
6734 return $_[0] !~ m/$balanced_brace_re/;
6735 } ## end sub unbalanced
6739 C<gets()> is a primitive (very primitive) routine to read continuations.
6740 It was devised for reading continuations for actions.
6741 it just reads more input with C<readline()> and returns it.
6746 return DB::readline("cont: ");
6749 =head2 C<_db_system()> - handle calls to<system()> without messing up the debugger
6751 The C<system()> function assumes that it can just go ahead and use STDIN and
6752 STDOUT, but under the debugger, we want it to use the debugger's input and
6755 C<_db_system()> socks away the program's STDIN and STDOUT, and then substitutes
6756 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
6757 and then puts everything back again.
6763 # We save, change, then restore STDIN and STDOUT to avoid fork() since
6764 # some non-Unix systems can do system() but have problems with fork().
6765 open( SAVEIN, "<&STDIN" ) || _db_warn("Can't save STDIN");
6766 open( SAVEOUT, ">&STDOUT" ) || _db_warn("Can't save STDOUT");
6767 open( STDIN, "<&IN" ) || _db_warn("Can't redirect STDIN");
6768 open( STDOUT, ">&OUT" ) || _db_warn("Can't redirect STDOUT");
6770 # XXX: using csh or tcsh destroys sigint retvals!
6772 open( STDIN, "<&SAVEIN" ) || _db_warn("Can't restore STDIN");
6773 open( STDOUT, ">&SAVEOUT" ) || _db_warn("Can't restore STDOUT");
6777 # most of the $? crud was coping with broken cshisms
6779 _db_warn( "(Command exited ", ( $? >> 8 ), ")\n" );
6783 "(Command died of SIG#",
6785 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6794 *system = \&_db_system;
6796 =head1 TTY MANAGEMENT
6798 The subs here do some of the terminal management for multiple debuggers.
6802 Top-level function called when we want to set up a new terminal for use
6805 If the C<noTTY> debugger option was set, we'll either use the terminal
6806 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6807 to find one. If we're a forked debugger, we call C<resetterm> to try to
6808 get a whole new terminal if we can.
6810 In either case, we set up the terminal next. If the C<ReadLine> option was
6811 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6812 the appropriate attributes. We then
6816 use vars qw($ornaments);
6817 use vars qw($rl_attribs);
6821 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6824 require Term::ReadLine;
6826 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6829 my ( $i, $o ) = split $tty, /,/;
6830 $o = $i unless defined $o;
6831 open( IN, '<', $i ) or die "Cannot open TTY '$i' for read: $!";
6832 open( OUT, '>', $o ) or die "Cannot open TTY '$o' for write: $!";
6838 # We don't have a TTY - try to find one via Term::Rendezvous.
6840 require Term::Rendezvous;
6842 # See if we have anything to pass to Term::Rendezvous.
6843 # Use $HOME/.perldbtty$$ if not.
6844 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6846 # Rendezvous and get the filehandles.
6847 my $term_rv = Term::Rendezvous->new( $rv );
6849 $OUT = $term_rv->OUT;
6850 } ## end else [ if ($tty)
6851 } ## end if ($notty)
6853 # We're a daughter debugger. Try to fork off another TTY.
6854 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6858 # If we shouldn't use Term::ReadLine, don't.
6860 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6863 # We're using Term::ReadLine. Get all the attributes for this terminal.
6865 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6867 $rl_attribs = $term->Attribs;
6868 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6869 if defined $rl_attribs->{basic_word_break_characters}
6870 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6871 $rl_attribs->{special_prefixes} = '$@&%';
6872 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6873 $rl_attribs->{completion_function} = \&db_complete;
6874 } ## end else [ if (!$rl)
6876 # Set up the LINEINFO filehandle.
6877 $LINEINFO = $OUT unless defined $LINEINFO;
6878 $lineinfo = $console unless defined $lineinfo;
6884 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6885 $term->SetHistory(@hist);
6888 # XXX Ornaments are turned on unconditionally, which is not
6889 # always a good thing.
6890 ornaments($ornaments) if defined $ornaments;
6892 } ## end sub setterm
6895 $histfile //= option_val("HistFile", undef);
6896 return unless defined $histfile;
6897 open my $fh, "<", $histfile or return;
6908 return unless defined $histfile;
6909 eval { require File::Path } or return;
6910 eval { require File::Basename } or return;
6911 File::Path::mkpath(File::Basename::dirname($histfile));
6912 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6913 $histsize //= option_val("HistSize",100);
6914 my @copy = grep { $_ ne '?' } @hist;
6915 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6916 for ($start .. $#copy) {
6917 print $fh "$copy[$_]\n";
6919 close $fh or die "Could not write '$histfile': $!";
6922 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6924 When the process being debugged forks, or the process invokes a command
6925 via C<system()> which starts a new debugger, we need to be able to get a new
6926 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6927 fight over the terminal, and you can never quite be sure who's going to get the
6928 input you're typing.
6930 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6931 is tasked with doing all the necessary operating system mojo to get a new
6932 TTY (and probably another window) and to direct the new debugger to read and
6935 The debugger provides C<get_fork_TTY> functions which work for TCP
6936 socket servers, X11, OS/2, and Mac OS X. Other systems are not
6937 supported. You are encouraged to write C<get_fork_TTY> functions which
6938 work for I<your> platform and contribute them.
6940 =head3 C<socket_get_fork_TTY>
6944 sub connect_remoteport {
6947 my $socket = IO::Socket::INET->new(
6949 PeerAddr => $remoteport,
6953 die "Unable to connect to remote host: $remoteport\n";
6958 sub socket_get_fork_TTY {
6959 $tty = $LINEINFO = $IN = $OUT = connect_remoteport();
6961 # Do I need to worry about setting $term?
6963 reset_IN_OUT( $IN, $OUT );
6967 =head3 C<xterm_get_fork_TTY>
6969 This function provides the C<get_fork_TTY> function for X11. If a
6970 program running under the debugger forks, a new <xterm> window is opened and
6971 the subsidiary debugger is directed there.
6973 The C<open()> call is of particular note here. We have the new C<xterm>
6974 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6975 command (which prints the device name of the TTY we'll want to use for input
6976 and output to STDOUT, then C<sleep> for a very long time, routing this output
6977 to file number 3. This way we can simply read from the <XT> filehandle (which
6978 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6980 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6985 sub xterm_get_fork_TTY {
6986 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6988 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6991 # Get the output from 'tty' and clean it up a little.
6995 $pidprompt = ''; # Shown anyway in titlebar
6997 # We need $term defined or we can not switch to the newly created xterm
6998 if ($tty ne '' && !defined $term) {
6999 require Term::ReadLine;
7001 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
7004 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
7007 # There's our new TTY.
7009 } ## end sub xterm_get_fork_TTY
7011 =head3 C<os2_get_fork_TTY>
7013 XXX It behooves an OS/2 expert to write the necessary documentation for this!
7017 # This example function resets $IN, $OUT itself
7019 sub os2_get_fork_TTY { # A simplification of the following (and works without):
7021 ( my $name = $0 ) =~ s,^.*[/\\],,s;
7022 my %opt = ( title => "Daughter Perl debugger $pids $name",
7023 ($rl ? (read_by_key => 1) : ()) );
7024 require OS2::Process;
7025 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
7027 $pidprompt = ''; # Shown anyway in titlebar
7028 reset_IN_OUT($in, $out);
7030 return ''; # Indicate that reset_IN_OUT is called
7031 } ## end sub os2_get_fork_TTY
7033 =head3 C<macosx_get_fork_TTY>
7035 The Mac OS X version uses AppleScript to tell Terminal.app to create
7040 # Notes about Terminal.app's AppleScript support,
7041 # (aka things that might break in future OS versions).
7043 # The "do script" command doesn't return a reference to the new window
7044 # it creates, but since it appears frontmost and windows are enumerated
7045 # front to back, we can use "first window" === "window 1".
7047 # Since "do script" is implemented by supplying the argument (plus a
7048 # return character) as terminal input, there's a potential race condition
7049 # where the debugger could beat the shell to reading the command.
7050 # To prevent this, we wait for the screen to clear before proceeding.
7053 # There's no direct accessor for the tty device name, so we fiddle
7054 # with the window title options until it says what we want.
7057 # There _is_ a direct accessor for the tty device name, _and_ there's
7058 # a new possible component of the window title (the name of the settings
7059 # set). A separate version is needed.
7061 my @script_versions=
7063 ([237, <<'__LEOPARD__'],
7064 tell application "Terminal"
7065 do script "clear;exec sleep 100000"
7066 tell first tab of first window
7068 set custom title to "forked perl debugger"
7069 set title displays custom title to true
7070 repeat while (length of first paragraph of (get contents)) > 0
7078 [100, <<'__JAGUAR_TIGER__'],
7079 tell application "Terminal"
7080 do script "clear;exec sleep 100000"
7082 set title displays shell path to false
7083 set title displays window size to false
7084 set title displays file name to false
7085 set title displays device name to true
7086 set title displays custom title to true
7087 set custom title to ""
7088 copy "/dev/" & name to thetty
7089 set custom title to "forked perl debugger"
7090 repeat while (length of first paragraph of (get contents)) > 0
7100 sub macosx_get_fork_TTY
7102 my($version,$script,$pipe,$tty);
7104 return unless $version=$ENV{TERM_PROGRAM_VERSION};
7105 foreach my $entry (@script_versions) {
7106 if ($version>=$entry->[0]) {
7107 $script=$entry->[1];
7111 return unless defined($script);
7112 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
7113 $tty=readline($pipe);
7115 return unless defined($tty) && $tty =~ m(^/dev/);
7120 =head3 C<tmux_get_fork_TTY>
7122 Creates a split window for subprocesses when a process running under the
7123 perl debugger in Tmux forks.
7127 sub tmux_get_fork_TTY {
7128 return unless $ENV{TMUX};
7132 my $status = open $pipe, '-|', 'tmux', 'split-window',
7133 '-P', '-F', '#{pane_tty}', 'sleep 100000';
7145 if ( !defined $term ) {
7146 require Term::ReadLine;
7148 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
7151 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
7159 =head2 C<create_IN_OUT($flags)>
7161 Create a new pair of filehandles, pointing to a new TTY. If impossible,
7162 try to diagnose why.
7168 =item * 1 - Don't know how to create a new TTY.
7170 =item * 2 - Debugger has forked, but we can't get a new TTY.
7172 =item * 4 - standard debugger startup is happening.
7178 use vars qw($fork_TTY);
7180 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
7182 # If we know how to get a new TTY, do it! $in will have
7183 # the TTY name if get_fork_TTY works.
7184 my $in = get_fork_TTY(@_) if defined &get_fork_TTY;
7186 # It used to be that
7187 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
7189 if ( not defined $in ) {
7192 # We don't know how.
7193 print_help(<<EOP) if $why == 1;
7194 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
7198 print_help(<<EOP) if $why == 2;
7199 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
7200 This may be an asynchronous session, so the parent debugger may be active.
7203 # Note that both debuggers are fighting over the same input.
7204 print_help(<<EOP) if $why != 4;
7205 Since two debuggers fight for the same TTY, input is severely entangled.
7209 I know how to switch the output to a different window in xterms, OS/2
7210 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
7211 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
7212 B<DB::get_fork_TTY()> returning this.
7214 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
7215 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
7218 } ## end if (not defined $in)
7219 elsif ( $in ne '' ) {
7223 $console = ''; # Indicate no need to open-from-the-console
7226 } ## end sub create_IN_OUT
7230 Handles rejiggering the prompt when we've forked off a new debugger.
7232 If the new debugger happened because of a C<system()> that invoked a
7233 program under the debugger, the arrow between the old pid and the new
7234 in the prompt has I<two> dashes instead of one.
7236 We take the current list of pids and add this one to the end. If there
7237 isn't any list yet, we make one up out of the initial pid associated with
7238 the terminal and our new pid, sticking an arrow (either one-dashed or
7239 two dashed) in between them.
7241 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
7242 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
7247 sub resetterm { # We forked, so we need a different TTY
7249 # Needs to be passed to create_IN_OUT() as well.
7252 # resetterm(2): got in here because of a system() starting a debugger.
7253 # resetterm(1): just forked.
7254 my $systemed = $in > 1 ? '-' : '';
7256 # If there's already a list of pids, add this to the end.
7258 $pids =~ s/\]/$systemed->$$]/;
7261 # No pid list. Time to make one.
7263 $pids = "[$term_pid->$$]";
7266 # The prompt we're going to be using for this debugger.
7269 # We now 0wnz this terminal.
7272 # Just return if we're not supposed to try to create a new TTY.
7273 return unless $CreateTTY & $in;
7275 # Try to create a new IN/OUT pair.
7277 } ## end sub resetterm
7281 First, we handle stuff in the typeahead buffer. If there is any, we shift off
7282 the next line, print a message saying we got it, add it to the terminal
7283 history (if possible), and return it.
7285 If there's nothing in the typeahead buffer, check the command filehandle stack.
7286 If there are any filehandles there, read from the last one, and return the line
7287 if we got one. If not, we pop the filehandle off and close it, and try the
7288 next one up the stack.
7290 If we've emptied the filehandle stack, we check to see if we've got a socket
7291 open, and we read that and return it if we do. If we don't, we just call the
7292 core C<readline()> and return its value.
7298 # Localize to prevent it from being smashed in the program being debugged.
7301 # If there are stacked filehandles to read from ...
7302 # (Handle it before the typeahead, because we may call source/etc. from
7306 # Read from the last one in the stack.
7307 my $line = CORE::readline( $cmdfhs[-1] );
7309 # If we got a line ...
7311 ? ( print $OUT ">> $line" and return $line ) # Echo and return
7312 : close pop @cmdfhs; # Pop and close
7313 } ## end while (@cmdfhs)
7315 # Pull a line out of the typeahead if there's stuff there.
7318 # How many lines left.
7319 my $left = @typeahead;
7321 # Get the next line.
7322 my $got = shift @typeahead;
7324 # Print a message saying we got input from the typeahead.
7326 print $OUT "auto(-$left)", shift, $got, "\n";
7328 # Add it to the terminal history (if possible).
7329 $term->AddHistory($got)
7331 and defined $term->Features->{addHistory};
7333 } ## end if (@typeahead)
7335 # We really need to read some input. Turn off entry/exit trace and
7336 # return value printing.
7340 # Nothing on the filehandle stack. Socket?
7341 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
7343 # Send anything we have to send.
7344 $OUT->write( join( '', @_ ) );
7346 # Receive anything there is to receive.
7351 while ($first_time or (length($buf) && ($stuff .= $buf) !~ /\n/))
7354 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
7355 # XXX Don't know. You tell me.
7360 } ## end if (ref $OUT and UNIVERSAL::isa...
7362 # No socket. Just read from the terminal.
7364 return $term->readline(@_);
7366 } ## end sub readline
7368 =head1 OPTIONS SUPPORT ROUTINES
7370 These routines handle listing and setting option values.
7372 =head2 C<dump_option> - list the current value of an option setting
7374 This routine uses C<option_val> to look up the value for an option.
7375 It cleans up escaped single-quotes and then displays the option and
7381 my ( $opt, $val ) = @_;
7382 $val = option_val( $opt, 'N/A' );
7383 $val =~ s/([\\\'])/\\$1/g;
7384 printf $OUT "%20s = '%s'\n", $opt, $val;
7385 } ## end sub dump_option
7387 sub options2remember {
7388 foreach my $k (@RememberOnROptions) {
7389 $option{$k} = option_val( $k, 'N/A' );
7394 =head2 C<option_val> - find the current value of an option
7396 This can't just be a simple hash lookup because of the indirect way that
7397 the option values are stored. Some are retrieved by calling a subroutine,
7398 some are just variables.
7400 You must supply a default value to be used in case the option isn't set.
7405 my ( $opt, $default ) = @_;
7408 # Does this option exist, and is it a variable?
7409 # If so, retrieve the value via the value in %optionVars.
7410 if ( defined $optionVars{$opt}
7411 and defined ${ $optionVars{$opt} } )
7413 $val = ${ $optionVars{$opt} };
7416 # Does this option exist, and it's a subroutine?
7417 # If so, call the subroutine via the ref in %optionAction
7418 # and capture the value.
7419 elsif ( defined $optionAction{$opt}
7420 and defined &{ $optionAction{$opt} } )
7422 $val = &{ $optionAction{$opt} }();
7425 # If there's an action or variable for the supplied option,
7426 # but no value was set, use the default.
7427 elsif (defined $optionAction{$opt} and not defined $option{$opt}
7428 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
7433 # Otherwise, do the simple hash lookup.
7435 $val = $option{$opt};
7438 # If the value isn't defined, use the default.
7439 # Then return whatever the value is.
7440 $val = $default unless defined $val;
7442 } ## end sub option_val
7444 =head2 C<parse_options>
7446 Handles the parsing and execution of option setting/displaying commands.
7448 An option entered by itself is assumed to be I<set me to 1> (the default value)
7449 if the option is a boolean one. If not, the user is prompted to enter a valid
7450 value or to query the current value (via C<option? >).
7452 If C<option=value> is entered, we try to extract a quoted string from the
7453 value (if it is quoted). If it's not, we just use the whole value as-is.
7455 We load any modules required to service this option, and then we set it: if
7456 it just gets stuck in a variable, we do that; if there's a subroutine to
7457 handle setting the option, we call that.
7459 Finally, if we're running in interactive mode, we display the effect of the
7460 user's command back to the terminal, skipping this if we're setting things
7461 during initialization.
7471 # These options need a value. Don't allow them to be clobbered by accident.
7472 my %opt_needs_val = map { ( $_ => 1 ) } qw{
7473 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
7474 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
7477 while (length($s)) {
7480 # Clean off excess leading whitespace.
7481 $s =~ s/^\s+// && next;
7483 # Options are always all word characters, followed by a non-word
7485 if ($s !~ s/^(\w+)(\W?)//) {
7486 print {$OUT} "Invalid option '$s'\n";
7489 my ( $opt, $sep ) = ( $1, $2 );
7491 # Make sure that such an option exists.
7492 my $matches = ( grep { /^\Q$opt/ && ( $option = $_ ) } @options )
7493 || ( grep { /^\Q$opt/i && ( $option = $_ ) } @options );
7496 print {$OUT} "Unknown option '$opt'\n";
7500 print {$OUT} "Ambiguous option '$opt'\n";
7505 # '?' as separator means query, but must have whitespace after it.
7506 if ( "?" eq $sep ) {
7508 print {$OUT} "Option query '$opt?' followed by non-space '$s'\n" ;
7513 #&dump_option($opt);
7514 } ## end if ("?" eq $sep)
7516 # Separator is whitespace (or just a carriage return).
7517 # They're going for a default, which we assume is 1.
7518 elsif ( $sep !~ /\S/ ) {
7520 $val = "1"; # this is an evil default; make 'em set it!
7523 # Separator is =. Trying to set a value.
7524 elsif ( $sep eq "=" ) {
7526 # If quoted, extract a quoted string.
7527 if ($s =~ s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
7529 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
7532 # Not quoted. Use the whole thing. Warn about 'option='.
7536 print OUT qq(Option better cleared using $opt=""\n)
7538 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
7540 } ## end elsif ($sep eq "=")
7542 # "Quoted" with [], <>, or {}.
7543 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
7545 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
7546 $s =~ s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
7547 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last;
7548 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
7549 } ## end else [ if ("?" eq $sep)
7551 # Exclude non-booleans from getting set to 1 by default.
7552 if ( $opt_needs_val{$option} && $val_defaulted ) {
7553 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
7555 "Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n";
7557 } ## end if ($opt_needs_val{$option...
7559 # Save the option value.
7560 $option{$option} = $val if defined $val;
7562 # Load any module that this option requires.
7563 if ( defined($optionRequire{$option}) && defined($val) ) {
7567 require '$optionRequire{$option}';
7569 } || die $@ # XXX: shouldn't happen
7573 # Stick it in the proper variable if it goes in a variable.
7574 if (defined($optionVars{$option}) && defined($val)) {
7575 ${ $optionVars{$option} } = $val;
7578 # Call the appropriate sub if it gets set via sub.
7579 if (defined($optionAction{$option})
7580 && defined (&{ $optionAction{$option} })
7583 &{ $optionAction{$option} }($val);
7586 # Not initialization - echo the value we set it to.
7587 dump_option($option) if ($OUT ne \*STDERR);
7588 } ## end while (length)
7589 } ## end sub parse_options
7591 =head1 RESTART SUPPORT
7593 These routines are used to store (and restore) lists of items in environment
7594 variables during a restart.
7598 Set_list packages up items to be stored in a set of environment variables
7599 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
7600 the values). Values outside the standard ASCII charset are stored by encoding
7601 them as hexadecimal values.
7606 my ( $stem, @list ) = @_;
7609 # VAR_n: how many we have. Scalar assignment gets the number of items.
7610 $ENV{"${stem}_n"} = @list;
7612 # Grab each item in the list, escape the backslashes, encode the non-ASCII
7613 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
7614 for my $i ( 0 .. $#list ) {
7616 $val =~ s/\\/\\\\/g;
7617 no warnings 'experimental::regex_sets';
7618 $val =~ s/ ( (?[ [\000-\xFF] & [:^print:] ]) ) /
7619 "\\0x" . unpack('H2',$1)/xaeg;
7620 $ENV{"${stem}_$i"} = $val;
7621 } ## end for $i (0 .. $#list)
7622 } ## end sub set_list
7626 Reverse the set_list operation: grab VAR_n to see how many we should be getting
7627 back, and then pull VAR_0, VAR_1. etc. back out.
7634 my $n = delete $ENV{"${stem}_n"};
7636 for my $i ( 0 .. $n - 1 ) {
7637 $val = delete $ENV{"${stem}_$i"};
7638 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
7642 } ## end sub get_list
7644 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
7648 The C<catch()> subroutine is the essence of fast and low-impact. We simply
7649 set an already-existing global scalar variable to a constant value. This
7650 avoids allocating any memory possibly in the middle of something that will
7651 get all confused if we do, particularly under I<unsafe signals>.
7657 return; # Put nothing on the stack - malloc/free land!
7662 C<warn> emits a warning, by joining together its arguments and printing
7663 them, with couple of fillips.
7665 If the composited message I<doesn't> end with a newline, we automatically
7666 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
7667 to be set to the filehandle to be used to output warnings; it makes no
7668 assumptions about what filehandles are available.
7673 my ($msg) = join( "", @_ );
7674 $msg .= ": $!\n" unless $msg =~ /\n$/;
7681 =head1 INITIALIZATION TTY SUPPORT
7683 =head2 C<reset_IN_OUT>
7685 This routine handles restoring the debugger's input and output filehandles
7686 after we've tried and failed to move them elsewhere. In addition, it assigns
7687 the debugger's output filehandle to $LINEINFO if it was already open there.
7692 my $switch_li = $LINEINFO eq $OUT;
7694 # If there's a term and it's able to get a new tty, try to get one.
7695 if ( $term and $term->Features->{newTTY} ) {
7696 ( $IN, $OUT ) = ( shift, shift );
7697 $term->newTTY( $IN, $OUT );
7700 # This term can't get a new tty now. Better luck later.
7702 _db_warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n");
7705 # Set the filehndles up as they were.
7707 ( $IN, $OUT ) = ( shift, shift );
7710 # Unbuffer the output filehandle.
7713 # Point LINEINFO to the same output filehandle if it was there before.
7714 $LINEINFO = $OUT if $switch_li;
7715 } ## end sub reset_IN_OUT
7717 =head1 OPTION SUPPORT ROUTINES
7719 The following routines are used to process some of the more complicated
7724 Sets the input and output filehandles to the specified files or pipes.
7725 If the terminal supports switching, we go ahead and do it. If not, and
7726 there's already a terminal in place, we save the information to take effect
7729 If there's no terminal yet (for instance, during debugger initialization),
7730 we go ahead and set C<$console> and C<$tty> to the file indicated.
7736 if ( @_ and $term and $term->Features->{newTTY} ) {
7738 # This terminal supports switching to a new TTY.
7739 # Can be a list of two files, or on string containing both names,
7741 # XXX Should this perhaps be an assignment from @_?
7742 my ( $in, $out ) = shift;
7745 # Split list apart if supplied.
7746 ( $in, $out ) = split /,/, $in, 2;
7750 # Use the same file for both input and output.
7754 # Open file onto the debugger's filehandles, if you can.
7755 open IN, '<', $in or die "cannot open '$in' for read: $!";
7756 open OUT, '>', $out or die "cannot open '$out' for write: $!";
7758 # Swap to the new filehandles.
7759 reset_IN_OUT( \*IN, \*OUT );
7761 # Save the setting for later.
7763 } ## end if (@_ and $term and $term...
7765 # Terminal doesn't support new TTY, or doesn't support readline.
7766 # Can't do it now, try restarting.
7768 _db_warn("Too late to set TTY, enabled on next 'R'!\n");
7771 # Useful if done through PERLDB_OPTS:
7772 $console = $tty = shift if @_;
7774 # Return whatever the TTY is.
7780 Sets the C<$notty> global, controlling whether or not the debugger tries to
7781 get a terminal to read from. If called after a terminal is already in place,
7782 we save the value to use it if we're restarted.
7788 _db_warn("Too late to set noTTY, enabled on next 'R'!\n") if @_;
7790 $notty = shift if @_;
7796 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
7797 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
7798 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
7799 the value in case a restart is done so we can change it then.
7805 _db_warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_;
7809 } ## end sub ReadLine
7811 =head2 C<RemotePort>
7813 Sets the port that the debugger will try to connect to when starting up.
7814 If the terminal's already been set up, we can't do it, but we remember the
7815 setting in case the user does a restart.
7821 _db_warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
7823 $remoteport = shift if @_;
7825 } ## end sub RemotePort
7829 Checks with the terminal to see if C<Tk> is running, and returns true or
7830 false. Returns false if the current terminal doesn't support C<readline>.
7835 if ( ${ $term->Features }{tkRunning} ) {
7836 return $term->tkRunning(@_);
7840 print $OUT "tkRunning not supported by current ReadLine package.\n";
7843 } ## end sub tkRunning
7847 Sets nonstop mode. If a terminal's already been set up, it's too late; the
7848 debugger remembers the setting in case you restart, though.
7854 _db_warn("Too late to set up NonStop mode, enabled on next 'R'!\n")
7857 $runnonstop = shift if @_;
7859 } ## end sub NonStop
7863 _db_warn("Some flag changes could not take effect until next 'R'!\n")
7866 $^P = parse_DollarCaretP_flags(shift) if @_;
7867 expand_DollarCaretP_flags($^P);
7872 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
7880 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7887 Sets the shell escape command, and generates a printable copy to be used
7894 # If we got an argument, meta-quote it, and add '\b' if it
7895 # ends in a word character.
7897 $sh = quotemeta shift;
7898 $sh .= "\\b" if $sh =~ /\w$/;
7901 # Generate the printable version for the help:
7902 $psh = $sh; # copy it
7903 $psh =~ s/\\b$//; # Take off trailing \b if any
7904 $psh =~ s/\\(.)/$1/g; # De-escape
7905 $psh; # return the printable version
7906 } ## end sub shellBang
7910 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7911 was passed as the argument. (This means you can't override the terminal's
7917 if ( defined $term ) {
7919 # We don't want to show warning backtraces, but we do want die() ones.
7920 local $warnLevel = 0;
7921 local $dieLevel = 1;
7923 # No ornaments if the terminal doesn't support them.
7924 if (not $term->Features->{ornaments}) {
7928 return (eval { $term->ornaments(@_) } || '');
7931 # Use what was passed in if we can't determine it ourselves.
7938 } ## end sub ornaments
7940 =head2 C<recallCommand>
7942 Sets the recall command, and builds a printable version which will appear in
7949 # If there is input, metaquote it. Add '\b' if it ends with a word
7952 $rc = quotemeta shift;
7953 $rc .= "\\b" if $rc =~ /\w$/;
7956 # Build it into a printable version.
7957 $prc = $rc; # Copy it
7958 $prc =~ s/\\b$//; # Remove trailing \b
7959 $prc =~ s/\\(.)/$1/g; # Remove escapes
7960 return $prc; # Return the printable version
7961 } ## end sub recallCommand
7963 =head2 C<LineInfo> - where the line number information goes
7965 Called with no arguments, returns the file or pipe that line info should go to.
7967 Called with an argument (a file or a pipe), it opens that onto the
7968 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7969 file or pipe again to the caller.
7977 # If this is a valid "thing to be opened for output", tack a
7978 # '>' onto the front.
7979 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7981 # If this is a pipe, the stream points to a slave editor.
7982 $slave_editor = ( $stream =~ /^\|/ );
7984 my $new_lineinfo_fh;
7985 # Open it up and unbuffer it.
7986 open ($new_lineinfo_fh , $stream )
7987 or _db_warn("Cannot open '$stream' for write");
7988 $LINEINFO = $new_lineinfo_fh;
7989 _autoflush($LINEINFO);
7993 } ## end sub LineInfo
7995 =head1 COMMAND SUPPORT ROUTINES
7997 These subroutines provide functionality for various commands.
7999 =head2 C<list_modules>
8001 For the C<M> command: list modules loaded and their versions.
8002 Essentially just runs through the keys in %INC, picks each package's
8003 C<$VERSION> variable, gets the file name, and formats the information
8008 sub list_modules { # versions
8012 # keys are the "as-loaded" name, values are the fully-qualified path
8013 # to the file itself.
8015 $file = $_; # get the module name
8016 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
8017 s,/,::,g; # change '/' to '::'
8018 s/^perl5db$/DB/; # Special case: debugger
8019 # moves to package DB
8020 s/^Term::ReadLine::readline$/readline/; # simplify readline
8022 # If the package has a $VERSION package global (as all good packages
8023 # should!) decode it and save as partial message.
8024 my $pkg_version = do { no strict 'refs'; ${ $_ . '::VERSION' } };
8025 if ( defined $pkg_version ) {
8026 $version{$file} = "$pkg_version from ";
8029 # Finish up the message with the file the package came from.
8030 $version{$file} .= $INC{$file};
8031 } ## end for (keys %INC)
8033 # Hey, dumpit() formats a hash nicely, so why not use it?
8034 dumpit( $OUT, \%version );
8035 } ## end sub list_modules
8039 Sets up the monster string used to format and print the help.
8041 =head3 HELP MESSAGE FORMAT
8043 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
8044 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
8045 easy to parse and portable, but which still allows the help to be a little
8046 nicer than just plain text.
8048 Essentially, you define the command name (usually marked up with C<< B<> >>
8049 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
8050 newline. The descriptive text can also be marked up in the same way. If you
8051 need to continue the descriptive text to another line, start that line with
8052 just tabs and then enter the marked-up text.
8054 If you are modifying the help text, I<be careful>. The help-string parser is
8055 not very sophisticated, and if you don't follow these rules it will mangle the
8056 help beyond hope until you fix the string.
8060 use vars qw($pre580_help);
8061 use vars qw($pre580_summary);
8065 # XXX: make sure there are tabs between the command and explanation,
8066 # or print_help will screw up your formatting if you have
8067 # eeevil ornaments enabled. This is an insane mess.
8070 Help is currently only available for the new 5.8 command set.
8071 No help is available for the old command set.
8072 We assume you know what you're doing if you switch to it.
8075 B<s> [I<expr>] Single step [in I<expr>].
8076 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
8077 <B<CR>> Repeat last B<n> or B<s> command.
8078 B<r> Return from current subroutine.
8079 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
8080 at the specified position.
8081 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
8082 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
8083 B<l> I<line> List single I<line>.
8084 B<l> I<subname> List first window of lines from subroutine.
8085 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
8086 B<l> List next window of lines.
8087 B<-> List previous window of lines.
8088 B<v> [I<line>] View window around I<line>.
8089 B<.> Return to the executed line.
8090 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
8091 I<filename> may be either the full name of the file, or a regular
8092 expression matching the full file name:
8093 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
8094 Evals (with saved bodies) are considered to be filenames:
8095 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
8096 (in the order of execution).
8097 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
8098 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
8099 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
8100 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
8101 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth).
8102 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
8103 B<b> Sets breakpoint on current line)
8104 B<b> [I<line>] [I<condition>]
8105 Set breakpoint; I<line> defaults to the current execution line;
8106 I<condition> breaks if it evaluates to true, defaults to '1'.
8107 B<b> I<subname> [I<condition>]
8108 Set breakpoint at first line of subroutine.
8109 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
8110 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
8111 B<b> B<postpone> I<subname> [I<condition>]
8112 Set breakpoint at first line of subroutine after
8114 B<b> B<compile> I<subname>
8115 Stop after the subroutine is compiled.
8116 B<B> [I<line>] Delete the breakpoint for I<line>.
8117 B<B> I<*> Delete all breakpoints.
8118 B<a> [I<line>] I<command>
8119 Set an action to be done before the I<line> is executed;
8120 I<line> defaults to the current execution line.
8121 Sequence is: check for breakpoint/watchpoint, print line
8122 if necessary, do action, prompt user if necessary,
8125 B<A> [I<line>] Delete the action for I<line>.
8126 B<A> I<*> Delete all actions.
8127 B<w> I<expr> Add a global watch-expression.
8129 B<W> I<expr> Delete a global watch-expression.
8130 B<W> I<*> Delete all watch-expressions.
8131 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
8132 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
8133 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
8134 B<x> I<expr> Evals expression in list context, dumps the result.
8135 B<m> I<expr> Evals expression in list context, prints methods callable
8136 on the first element of the result.
8137 B<m> I<class> Prints methods callable via the given class.
8138 B<M> Show versions of loaded modules.
8139 B<i> I<class> Prints nested parents of given class.
8140 B<e> Display current thread id.
8141 B<E> Display all thread ids the current one will be identified: <n>.
8142 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8144 B<<> ? List Perl commands to run before each prompt.
8145 B<<> I<expr> Define Perl command to run before each prompt.
8146 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
8147 B<< *> Delete the list of perl commands to run before each prompt.
8148 B<>> ? List Perl commands to run after each prompt.
8149 B<>> I<expr> Define Perl command to run after each prompt.
8150 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
8151 B<>>B< *> Delete the list of Perl commands to run after each prompt.
8152 B<{> I<db_command> Define debugger command to run before each prompt.
8153 B<{> ? List debugger commands to run before each prompt.
8154 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
8155 B<{ *> Delete the list of debugger commands to run before each prompt.
8156 B<$prc> I<number> Redo a previous command (default previous command).
8157 B<$prc> I<-number> Redo number'th-to-last command.
8158 B<$prc> I<pattern> Redo last command that started with I<pattern>.
8159 See 'B<O> I<recallCommand>' too.
8160 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
8165 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
8167 See 'B<O> I<shellBang>' too.
8168 B<source> I<file> Execute I<file> containing debugger commands (may nest).
8169 B<save> I<file> Save current debugger session (actual history) to I<file>.
8170 B<rerun> Rerun session to current position.
8171 B<rerun> I<n> Rerun session to numbered command.
8172 B<rerun> I<-n> Rerun session to number'th-to-last command.
8173 B<H> I<-number> Display last number commands (default all).
8174 B<H> I<*> Delete complete history.
8175 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
8176 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
8177 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well.
8178 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
8179 I<command> Execute as a perl statement in current package.
8180 B<R> Pure-man-restart of debugger, some of debugger state
8181 and command-line options may be lost.
8182 Currently the following settings are preserved:
8183 history, breakpoints and actions, debugger B<O>ptions
8184 and the following command-line options: I<-w>, I<-I>, I<-e>.
8186 B<o> [I<opt>] ... Set boolean option to true
8187 B<o> [I<opt>B<?>] Query options
8188 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
8189 Set options. Use quotes if spaces in value.
8190 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
8191 I<pager> program for output of \"|cmd\";
8192 I<tkRunning> run Tk while prompting (with ReadLine);
8193 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
8194 I<inhibit_exit> Allows stepping off the end of the script.
8195 I<ImmediateStop> Debugger should stop as early as possible.
8196 I<RemotePort> Remote hostname:port for remote debugging
8197 The following options affect what happens with B<V>, B<X>, and B<x> commands:
8198 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
8199 I<compactDump>, I<veryCompact> change style of array and hash dump;
8200 I<globPrint> whether to print contents of globs;
8201 I<DumpDBFiles> dump arrays holding debugged files;
8202 I<DumpPackages> dump symbol tables of packages;
8203 I<DumpReused> dump contents of \"reused\" addresses;
8204 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
8205 I<bareStringify> Do not print the overload-stringified value;
8206 Other options include:
8207 I<PrintRet> affects printing of return value after B<r> command,
8208 I<frame> affects printing messages on subroutine entry/exit.
8209 I<AutoTrace> affects printing messages on possible breaking points.
8210 I<maxTraceLen> gives max length of evals/args listed in stack trace.
8211 I<ornaments> affects screen appearance of the command line.
8212 I<CreateTTY> bits control attempts to create a new TTY on events:
8213 1: on fork() 2: debugger is started inside debugger
8215 During startup options are initialized from \$ENV{PERLDB_OPTS}.
8216 You can put additional initialization options I<TTY>, I<noTTY>,
8217 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
8218 B<R> after you set them).
8220 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
8221 B<h> Summary of debugger commands.
8222 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
8223 B<h h> Long help for debugger commands
8224 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
8225 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
8226 Set B<\$DB::doccmd> to change viewer.
8228 Type '|h h' for a paged display if this was too hard to read.
8230 "; # Fix balance of vi % matching: }}}}
8232 # note: tabs in the following section are not-so-helpful
8233 $summary = <<"END_SUM";
8234 I<List/search source lines:> I<Control script execution:>
8235 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8236 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8237 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
8238 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8239 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8240 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
8241 I<Debugger controls:> B<L> List break/watch/actions
8242 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr]
8243 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8244 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
8245 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8246 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
8247 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
8248 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
8249 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8250 B<q> or B<^D> Quit B<R> Attempt a restart
8251 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8252 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8253 B<p> I<expr> Print expression (uses script's current package).
8254 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8255 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8256 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
8257 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8258 B<e> Display thread id B<E> Display all thread ids.
8259 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8262 # ')}}; # Fix balance of vi % matching
8264 # and this is really numb...
8267 B<s> [I<expr>] Single step [in I<expr>].
8268 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
8269 B<CR>> Repeat last B<n> or B<s> command.
8270 B<r> Return from current subroutine.
8271 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
8272 at the specified position.
8273 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
8274 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
8275 B<l> I<line> List single I<line>.
8276 B<l> I<subname> List first window of lines from subroutine.
8277 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
8278 B<l> List next window of lines.
8279 B<-> List previous window of lines.
8280 B<w> [I<line>] List window around I<line>.
8281 B<.> Return to the executed line.
8282 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
8283 I<filename> may be either the full name of the file, or a regular
8284 expression matching the full file name:
8285 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
8286 Evals (with saved bodies) are considered to be filenames:
8287 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
8288 (in the order of execution).
8289 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
8290 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
8291 B<L> List all breakpoints and actions.
8292 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
8293 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) .
8294 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
8295 B<b> [I<line>] [I<condition>]
8296 Set breakpoint; I<line> defaults to the current execution line;
8297 I<condition> breaks if it evaluates to true, defaults to '1'.
8298 B<b> I<subname> [I<condition>]
8299 Set breakpoint at first line of subroutine.
8300 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
8301 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
8302 B<b> B<postpone> I<subname> [I<condition>]
8303 Set breakpoint at first line of subroutine after
8305 B<b> B<compile> I<subname>
8306 Stop after the subroutine is compiled.
8307 B<d> [I<line>] Delete the breakpoint for I<line>.
8308 B<D> Delete all breakpoints.
8309 B<a> [I<line>] I<command>
8310 Set an action to be done before the I<line> is executed;
8311 I<line> defaults to the current execution line.
8312 Sequence is: check for breakpoint/watchpoint, print line
8313 if necessary, do action, prompt user if necessary,
8315 B<a> [I<line>] Delete the action for I<line>.
8316 B<A> Delete all actions.
8317 B<W> I<expr> Add a global watch-expression.
8318 B<W> Delete all watch-expressions.
8319 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
8320 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
8321 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
8322 B<x> I<expr> Evals expression in list context, dumps the result.
8323 B<m> I<expr> Evals expression in list context, prints methods callable
8324 on the first element of the result.
8325 B<m> I<class> Prints methods callable via the given class.
8327 B<<> ? List Perl commands to run before each prompt.
8328 B<<> I<expr> Define Perl command to run before each prompt.
8329 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
8330 B<>> ? List Perl commands to run after each prompt.
8331 B<>> I<expr> Define Perl command to run after each prompt.
8332 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
8333 B<{> I<db_command> Define debugger command to run before each prompt.
8334 B<{> ? List debugger commands to run before each prompt.
8335 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
8336 B<$prc> I<number> Redo a previous command (default previous command).
8337 B<$prc> I<-number> Redo number'th-to-last command.
8338 B<$prc> I<pattern> Redo last command that started with I<pattern>.
8339 See 'B<O> I<recallCommand>' too.
8340 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
8345 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
8347 See 'B<O> I<shellBang>' too.
8348 B<source> I<file> Execute I<file> containing debugger commands (may nest).
8349 B<H> I<-number> Display last number commands (default all).
8350 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
8351 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
8352 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
8353 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
8354 I<command> Execute as a perl statement in current package.
8355 B<v> Show versions of loaded modules.
8356 B<R> Pure-man-restart of debugger, some of debugger state
8357 and command-line options may be lost.
8358 Currently the following settings are preserved:
8359 history, breakpoints and actions, debugger B<O>ptions
8360 and the following command-line options: I<-w>, I<-I>, I<-e>.
8362 B<O> [I<opt>] ... Set boolean option to true
8363 B<O> [I<opt>B<?>] Query options
8364 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
8365 Set options. Use quotes if spaces in value.
8366 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
8367 I<pager> program for output of \"|cmd\";
8368 I<tkRunning> run Tk while prompting (with ReadLine);
8369 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
8370 I<inhibit_exit> Allows stepping off the end of the script.
8371 I<ImmediateStop> Debugger should stop as early as possible.
8372 I<RemotePort> Remote hostname:port for remote debugging
8373 The following options affect what happens with B<V>, B<X>, and B<x> commands:
8374 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
8375 I<compactDump>, I<veryCompact> change style of array and hash dump;
8376 I<globPrint> whether to print contents of globs;
8377 I<DumpDBFiles> dump arrays holding debugged files;
8378 I<DumpPackages> dump symbol tables of packages;
8379 I<DumpReused> dump contents of \"reused\" addresses;
8380 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
8381 I<bareStringify> Do not print the overload-stringified value;
8382 Other options include:
8383 I<PrintRet> affects printing of return value after B<r> command,
8384 I<frame> affects printing messages on subroutine entry/exit.
8385 I<AutoTrace> affects printing messages on possible breaking points.
8386 I<maxTraceLen> gives max length of evals/args listed in stack trace.
8387 I<ornaments> affects screen appearance of the command line.
8388 I<CreateTTY> bits control attempts to create a new TTY on events:
8389 1: on fork() 2: debugger is started inside debugger
8391 During startup options are initialized from \$ENV{PERLDB_OPTS}.
8392 You can put additional initialization options I<TTY>, I<noTTY>,
8393 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
8394 B<R> after you set them).
8396 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
8397 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
8398 B<h h> Summary of debugger commands.
8399 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
8400 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
8401 Set B<\$DB::doccmd> to change viewer.
8403 Type '|h' for a paged display if this was too hard to read.
8405 "; # Fix balance of vi % matching: }}}}
8407 # note: tabs in the following section are not-so-helpful
8408 $pre580_summary = <<"END_SUM";
8409 I<List/search source lines:> I<Control script execution:>
8410 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8411 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8412 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
8413 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8414 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8415 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
8416 I<Debugger controls:> B<L> List break/watch/actions
8417 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
8418 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8419 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
8420 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8421 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
8422 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
8423 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8424 B<q> or B<^D> Quit B<R> Attempt a restart
8425 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8426 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8427 B<p> I<expr> Print expression (uses script's current package).
8428 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8429 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8430 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
8431 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8432 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8435 # ')}}; # Fix balance of vi % matching
8437 } ## end sub sethelp
8439 =head2 C<print_help()>
8441 Most of what C<print_help> does is just text formatting. It finds the
8442 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
8443 terminal control characters to simulate them (courtesy of
8444 C<Term::ReadLine::TermCap>).
8449 my $help_str = shift;
8451 # Restore proper alignment destroyed by eeevil I<> and B<>
8452 # ornaments: A pox on both their houses!
8454 # A help command will have everything up to and including
8455 # the first tab sequence padded into a field 16 (or if indented 20)
8456 # wide. If it's wider than that, an extra space will be added.
8458 ^ # only matters at start of line
8459 ( \ {4} | \t )* # some subcommands are indented
8460 ( < ? # so <CR> works
8461 [BI] < [^\t\n] + ) # find an eeevil ornament
8462 ( \t+ ) # original separation, discarded
8463 ( .* ) # this will now start (no earlier) than
8466 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
8467 my $clean = $command;
8468 $clean =~ s/[BI]<([^>]*)>/$1/g;
8470 # replace with this whole string:
8471 ($leadwhite ? " " x 4 : "")
8473 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
8478 $help_str =~ s{ # handle bold ornaments
8479 B < ( [^>] + | > ) >
8481 $Term::ReadLine::TermCap::rl_term_set[2]
8483 . $Term::ReadLine::TermCap::rl_term_set[3]
8486 $help_str =~ s{ # handle italic ornaments
8487 I < ( [^>] + | > ) >
8489 $Term::ReadLine::TermCap::rl_term_set[0]
8491 . $Term::ReadLine::TermCap::rl_term_set[1]
8495 print {$OUT} $help_str;
8498 } ## end sub print_help
8502 This routine does a lot of gyrations to be sure that the pager is C<less>.
8503 It checks for C<less> masquerading as C<more> and records the result in
8504 C<$fixed_less> so we don't have to go through doing the stats again.
8508 use vars qw($fixed_less);
8511 if ($pager =~ /\bless\b/)
8515 elsif ($pager =~ /\bmore\b/)
8517 # Nope, set to more. See what's out there.
8518 my @st_more = stat('/usr/bin/more');
8519 my @st_less = stat('/usr/bin/less');
8521 # is it really less, pretending to be more?
8525 && $st_more[0] == $st_less[0]
8526 && $st_more[1] == $st_less[1]
8536 # We already know if this is set.
8537 return if $fixed_less;
8539 # changes environment!
8540 # 'r' added so we don't do (slow) stats again.
8541 $fixed_less = 1 if _calc_is_less();
8544 } ## end sub fix_less
8546 =head1 DIE AND WARN MANAGEMENT
8550 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
8551 to debug a debugger problem.
8553 It does its best to report the error that occurred, and then forces the
8554 program, debugger, and everything to die.
8560 # No entry/exit messages.
8563 # No return value prints.
8566 # set the abort signal handling to the default (just terminate).
8567 $SIG{'ABRT'} = 'DEFAULT';
8569 # If we enter the signal handler recursively, kill myself with an
8570 # abort signal (so we just terminate).
8571 kill 'ABRT', $$ if $panic++;
8573 # If we can show detailed info, do so.
8574 if ( defined &Carp::longmess ) {
8576 # Don't recursively enter the warn handler, since we're carping.
8577 local $SIG{__WARN__} = '';
8579 # Skip two levels before reporting traceback: we're skipping
8580 # mydie and confess.
8581 local $Carp::CarpLevel = 2; # mydie + confess
8583 # Tell us all about it.
8584 _db_warn( Carp::longmess("Signal @_") );
8587 # No Carp. Tell us about the signal as best we can.
8590 print $DB::OUT "Got signal @_\n";
8595 } ## end sub diesignal
8599 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
8600 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
8606 # No entry/exit trace.
8609 # No return value printing.
8612 # Turn off warn and die handling to prevent recursive entries to this
8614 local $SIG{__WARN__} = '';
8615 local $SIG{__DIE__} = '';
8617 # Load Carp if we can. If $^S is false (current thing being compiled isn't
8618 # done yet), we may not be able to do a require.
8619 eval { require Carp }
8620 if defined $^S; # If error/warning during compilation,
8621 # require may be broken.
8623 # Use the core warn() unless Carp loaded OK.
8625 "\nCannot print stack trace, load with -MCarp option to see stack" ),
8627 unless defined &Carp::longmess;
8629 # Save the current values of $single and $trace, and then turn them off.
8630 my ( $mysingle, $mytrace ) = ( $single, $trace );
8634 # We can call Carp::longmess without its being "debugged" (which we
8635 # don't want - we just want to use it!). Capture this for later.
8636 my $mess = Carp::longmess(@_);
8638 # Restore $single and $trace to their original values.
8639 ( $single, $trace ) = ( $mysingle, $mytrace );
8641 # Use the debugger's own special way of printing warnings to print
8642 # the stack trace message.
8648 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
8649 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
8650 single stepping and tracing during the call to C<Carp::longmess> to avoid
8651 debugging it - we just want to use it.
8653 If C<dieLevel> is zero, we let the program being debugged handle the
8654 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
8655 the debugger takes over all exception handling, printing a backtrace and
8656 displaying the exception via its C<dbwarn()> routine.
8663 local $SIG{__DIE__} = '';
8664 local $SIG{__WARN__} = '';
8665 if ( $dieLevel > 2 ) {
8666 local $SIG{__WARN__} = \&dbwarn;
8667 _db_warn(@_); # Yell no matter what
8670 if ( $dieLevel < 2 ) {
8671 die @_ if $^S; # in eval propagate
8674 # The code used to check $^S to see if compilation of the current thing
8675 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
8676 eval { require Carp };
8679 "\nCannot print stack trace, load with -MCarp option to see stack" )
8680 unless defined &Carp::longmess;
8682 # We do not want to debug this chunk (automatic disabling works
8683 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
8684 # get the stack trace from Carp::longmess (if possible), restore $signal
8685 # and $trace, and then die with the stack trace.
8686 my ( $mysingle, $mytrace ) = ( $single, $trace );
8692 package Carp; # Do not include us in the list
8693 eval { $mess = Carp::longmess(@_); };
8695 ( $single, $trace ) = ( $mysingle, $mytrace );
8699 =head2 C<warnlevel()>
8701 Set the C<$DB::warnLevel> variable that stores the value of the
8702 C<warnLevel> option. Calling C<warnLevel()> with a positive value
8703 results in the debugger taking over all warning handlers. Setting
8704 C<warnLevel> to zero leaves any warning handlers set up by the program
8705 being debugged in place.
8711 my $prevwarn = $SIG{__WARN__} unless $warnLevel;
8714 $SIG{__WARN__} = \&DB::dbwarn;
8717 $SIG{__WARN__} = $prevwarn;
8719 undef $SIG{__WARN__};
8723 } ## end sub warnLevel
8727 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
8728 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
8729 zero lets you use your own C<die()> handler.
8736 my $prevdie = $SIG{__DIE__} unless $dieLevel;
8740 # Always set it to dbdie() for non-zero values.
8741 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
8743 # No longer exists, so don't try to use it.
8744 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
8746 # If we've finished initialization, mention that stack dumps
8747 # are enabled, If dieLevel is 1, we won't stack dump if we die
8749 print $OUT "Stack dump during die enabled",
8750 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
8753 # XXX This is probably obsolete, given that diehard() is gone.
8754 print $OUT "Dump printed too.\n" if $dieLevel > 2;
8755 } ## end if ($dieLevel)
8757 # Put the old one back if there was one.
8759 $SIG{__DIE__} = $prevdie;
8760 print $OUT "Default die handler restored.\n";
8762 undef $SIG{__DIE__};
8763 print $OUT "Die handler removed.\n";
8767 } ## end sub dieLevel
8769 =head2 C<signalLevel>
8771 Number three in a series: set C<signalLevel> to zero to keep your own
8772 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
8773 takes over and handles them with C<DB::diesignal()>.
8779 my $prevsegv = $SIG{SEGV} unless $signalLevel;
8780 my $prevbus = $SIG{BUS} unless $signalLevel;
8781 $signalLevel = shift;
8783 $SIG{SEGV} = \&DB::diesignal;
8784 $SIG{BUS} = \&DB::diesignal;
8787 $SIG{SEGV} = $prevsegv;
8788 $SIG{BUS} = $prevbus;
8792 } ## end sub signalLevel
8794 =head1 SUBROUTINE DECODING SUPPORT
8796 These subroutines are used during the C<x> and C<X> commands to try to
8797 produce as much information as possible about a code reference. They use
8798 L<Devel::Peek> to try to find the glob in which this code reference lives
8799 (if it does) - this allows us to actually code references which correspond
8800 to named subroutines (including those aliased via glob assignment).
8802 =head2 C<CvGV_name()>
8804 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
8805 via that routine. If this fails, return the reference again (when the
8806 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
8812 my $name = CvGV_name_or_bust($in);
8813 defined $name ? $name : $in;
8816 =head2 C<CvGV_name_or_bust> I<coderef>
8818 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
8819 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
8820 find a glob for this ref.
8822 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
8826 use vars qw($skipCvGV);
8828 sub CvGV_name_or_bust {
8830 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
8831 return unless ref $in;
8832 $in = \&$in; # Hard reference...
8833 eval { require Devel::Peek; 1 } or return;
8834 my $gv = Devel::Peek::CvGV($in) or return;
8835 *$gv{PACKAGE} . '::' . *$gv{NAME};
8836 } ## end sub CvGV_name_or_bust
8840 A utility routine used in various places; finds the file where a subroutine
8841 was defined, and returns that filename and a line-number range.
8843 Tries to use C<@sub> first; if it can't find it there, it tries building a
8844 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
8845 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
8846 this way, it brute-force searches C<%sub>, checking for identical references.
8850 sub _find_sub_helper {
8853 return unless defined &$subr;
8854 my $name = CvGV_name_or_bust($subr);
8856 $data = $sub{$name} if defined $name;
8857 return $data if defined $data;
8860 $subr = \&$subr; # Hard reference
8863 $s = $_, last if $subr eq \&$_;
8878 return ( $sub{$subr} || _find_sub_helper($subr) );
8879 } ## end sub find_sub
8883 A subroutine that uses the utility function C<methods_via> to find all the
8884 methods in the class corresponding to the current reference and in
8893 # Figure out the class - either this is the class or it's a reference
8894 # to something blessed into that class.
8896 $class = ref $class if ref $class;
8900 # Show the methods that this class has.
8901 methods_via( $class, '', 1 );
8903 # Show the methods that UNIVERSAL has.
8904 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
8905 } ## end sub methods
8907 =head2 C<methods_via($class, $prefix, $crawl_upward)>
8909 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
8910 all the parent class methods. C<$class> is the name of the next class to
8911 try; C<$prefix> is the message prefix, which gets built up as we go up the
8912 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
8913 higher in the C<@ISA> tree, 0 if we should stop.
8919 # If we've processed this class already, just quit.
8921 return if $seen{$class}++;
8923 # This is a package that is contributing the methods we're about to print.
8925 my $prepend = $prefix ? "via $prefix: " : '';
8928 # Extract from all the symbols in this class.
8929 my $class_ref = do { no strict "refs"; \%{$class . '::'} };
8930 while (my ($name, $glob) = each %$class_ref) {
8931 # references directly in the symbol table are Proxy Constant
8932 # Subroutines, and are by their very nature defined
8933 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8934 # to a subroutine reference, which can be tested by defined.
8935 # $glob might also be the value -1 (from sub foo;)
8936 # or (say) '$$' (from sub foo ($$);)
8937 # \$glob will be SCALAR in both cases.
8938 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8939 && !$seen{$name}++) {
8940 push @to_print, "$prepend$name\n";
8947 print $DB::OUT $_ foreach sort @to_print;
8950 # If the $crawl_upward argument is false, just quit here.
8951 return unless shift;
8953 # $crawl_upward true: keep going up the tree.
8954 # Find all the classes this one is a subclass of.
8955 my $class_ISA_ref = do { no strict "refs"; \@{"${class}::ISA"} };
8956 for my $name ( @$class_ISA_ref ) {
8958 # Set up the new prefix.
8959 $prepend = $prefix ? $prefix . " -> $name" : $name;
8961 # Crawl up the tree and keep trying to crawl up.
8962 methods_via( $name, $prepend, 1 );
8964 } ## end sub methods_via
8966 =head2 C<setman> - figure out which command to use to show documentation
8968 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8973 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|NetWare)\z/s
8974 ? "man" # O Happy Day!
8975 : "perldoc"; # Alas, poor unfortunates
8978 =head2 C<runman> - run the appropriate command to show documentation
8980 Accepts a man page name; runs the appropriate command to display it (set up
8981 during debugger initialization). Uses C<_db_system()> to avoid mucking up the
8982 program's STDIN and STDOUT.
8989 _db_system("$doccmd $doccmd");
8993 # this way user can override, like with $doccmd="man -Mwhatever"
8994 # or even just "man " to disable the path check.
8995 if ( $doccmd ne 'man' ) {
8996 _db_system("$doccmd $page");
9000 $page = 'perl' if lc($page) eq 'help';
9003 my $man1dir = $Config::Config{man1direxp};
9004 my $man3dir = $Config::Config{man3direxp};
9005 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
9007 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
9008 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
9009 chop $manpath if $manpath;
9011 # harmless if missing, I figure
9012 local $ENV{MANPATH} = $manpath if $manpath;
9013 my $nopathopt = $^O =~ /dunno what goes here/;
9018 # I just *know* there are men without -M
9019 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
9024 unless ( $page =~ /^perl\w/ ) {
9025 # Previously the debugger contained a list which it slurped in,
9026 # listing the known "perl" manpages. However, it was out of date,
9027 # with errors both of omission and inclusion. This approach is
9028 # considerably less complex. The failure mode on a butchered
9029 # install is simply that the user has to run man or perldoc
9030 # "manually" with the full manpage name.
9032 # There is a list of $^O values in installperl to determine whether
9033 # the directory is 'pods' or 'pod'. However, we can avoid tight
9034 # coupling to that by simply checking the "non-standard" 'pods'
9036 my $pods = "$Config::Config{privlibexp}/pods";
9037 $pods = "$Config::Config{privlibexp}/pod"
9039 if (-f "$pods/perl$page.pod") {
9040 CORE::system( $doccmd,
9041 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
9045 } ## end if (CORE::system($doccmd...
9048 #use Carp; # This did break, left for debugging
9050 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
9052 Because of the way the debugger interface to the Perl core is designed, any
9053 debugger package globals that C<DB::sub()> requires have to be defined before
9054 any subroutines can be called. These are defined in the second C<BEGIN> block.
9056 This block sets things up so that (basically) the world is sane
9057 before the debugger starts executing. We set up various variables that the
9058 debugger has to have set up before the Perl core starts running:
9064 The debugger's own filehandles (copies of STD and STDOUT for now).
9068 Characters for shell escapes, the recall command, and the history command.
9072 The maximum recursion depth.
9076 The size of a C<w> command's window.
9080 The before-this-line context to be printed in a C<v> (view a window around this line) command.
9084 The fact that we're not in a sub at all right now.
9088 The default SIGINT handler for the debugger.
9092 The appropriate value of the flag in C<$^D> that says the debugger is running
9096 The current debugger recursion level
9100 The list of postponed items and the C<$single> stack (XXX define this)
9104 That we want no return values and no subroutine entry/exit trace.
9110 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
9112 use vars qw($db_stop);
9114 BEGIN { # This does not compile, alas. (XXX eh?)
9115 $IN = \*STDIN; # For bugs before DB::OUT has been opened
9116 $OUT = \*STDERR; # For errors before DB::OUT has been opened
9118 # Define characters used by command parsing.
9119 $sh = '!'; # Shell escape (does not work)
9120 $rc = ','; # Recall command (does not work)
9121 @hist = ('?'); # Show history (does not work)
9122 @truehist = (); # Can be saved for replay (per session)
9124 # This defines the point at which you get the 'deep recursion'
9125 # warning. It MUST be defined or the debugger will not load.
9128 # Number of lines around the current one that are shown in the
9132 # How much before-the-current-line context the 'v' command should
9133 # use in calculating the start of the window it will display.
9136 # We're not in any sub yet, but we need this to be a defined value.
9139 # Set up the debugger's interrupt handler. It simply sets a flag
9140 # ($signal) that DB::DB() will check before each command is executed.
9141 $SIG{INT} = \&DB::catch;
9143 # The following lines supposedly, if uncommented, allow the debugger to
9144 # debug itself. Perhaps we can try that someday.
9145 # This may be enabled to debug debugger:
9146 #$warnLevel = 1 unless defined $warnLevel;
9147 #$dieLevel = 1 unless defined $dieLevel;
9148 #$signalLevel = 1 unless defined $signalLevel;
9150 # This is the flag that says "a debugger is running, please call
9151 # DB::DB and DB::sub". We will turn it on forcibly before we try to
9152 # execute anything in the user's context, because we always want to
9154 $db_stop = 0; # Compiler warning ...
9155 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
9157 # This variable records how many levels we're nested in debugging. Used
9158 # Used in the debugger prompt, and in determining whether it's all over or
9160 $level = 0; # Level of recursive debugging
9162 # "Triggers bug (?) in perl if we postpone this until runtime."
9163 # XXX No details on this yet, or whether we should fix the bug instead
9164 # of work around it. Stay tuned.
9167 # Used to track the current stack depth using the auto-stacked-variable
9169 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
9171 # Don't print return values on exiting a subroutine.
9174 # No extry/exit tracing.
9179 BEGIN { $^W = $ini_warn; } # Switch warnings back
9181 =head1 READLINE SUPPORT - COMPLETION FUNCTION
9185 C<readline> support - adds command completion to basic C<readline>.
9187 Returns a list of possible completions to C<readline> when invoked. C<readline>
9188 will print the longest common substring following the text already entered.
9190 If there is only a single possible completion, C<readline> will use it in full.
9192 This code uses C<map> and C<grep> heavily to create lists of possible
9193 completion. Think LISP in this section.
9199 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
9200 # $text is the text to be completed.
9201 # $line is the incoming line typed by the user.
9202 # $start is the start of the text to be completed in the incoming line.
9203 my ( $text, $line, $start ) = @_;
9205 # Save the initial text.
9206 # The search pattern is current package, ::, extract the next qualifier
9207 # Prefix and pack are set to undef.
9208 my ( $itext, $search, $prefix, $pack ) =
9209 ( $text, "^\Q${package}::\E([^:]+)\$" );
9211 =head3 C<b postpone|compile>
9217 Find all the subroutines that might match in this package
9221 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
9225 Include all the rest of the subs that are known
9229 C<grep> out the ones that match the text we have so far
9233 Return this as the list of possible completions
9239 return sort grep /^\Q$text/, ( keys %sub ),
9240 qw(postpone load compile), # subroutines
9241 ( map { /$search/ ? ($1) : () } keys %sub )
9242 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
9246 Get all the possible files from C<@INC> as it currently stands and
9247 select the ones that match the text so far.
9251 return sort grep /^\Q$text/, values %INC # files
9252 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
9254 =head3 C<V> (list variable) and C<m> (list modules)
9256 There are two entry points for these commands:
9258 =head4 Unqualified package names
9260 Get the top-level packages and grab everything that matches the text
9261 so far. For each match, recursively complete the partial packages to
9262 get all possible matching packages. Return this sorted list.
9266 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9267 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
9268 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
9270 =head4 Qualified package names
9272 Take a partially-qualified package and find all subpackages for it
9273 by getting all the subpackages for the package so far, matching all
9274 the subpackages against the text, and discarding all of them which
9275 start with 'main::'. Return this list.
9279 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9280 grep !/^main::/, grep /^\Q$text/,
9281 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () }
9282 do { no strict 'refs'; keys %{ $prefix . '::' } }
9283 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
9284 and $text =~ /^(.*[^:])::?(\w*)$/
9287 =head3 C<f> - switch files
9289 Here, we want to get a fully-qualified filename for the C<f> command.
9294 =item 1. The original source file itself
9296 =item 2. A file from C<@INC>
9298 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
9304 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
9305 # We might possibly want to switch to an eval (which has a "filename"
9306 # like '(eval 9)'), so we may need to clean up the completion text
9307 # before proceeding.
9308 $prefix = length($1) - length($text);
9313 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
9314 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
9315 out of C<%main::>, add the initial source file, and extract the ones that
9316 match the completion text so far.
9321 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
9323 } ## end if ($line =~ /^\|*f\s+(.*)/)
9325 =head3 Subroutine name completion
9327 We look through all of the defined subs (the keys of C<%sub>) and
9328 return both all the possible matches to the subroutine name plus
9329 all the matches qualified to the current package.
9333 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
9334 $text = substr $text, 1;
9336 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
9338 map { /$search/ ? ($1) : () }
9341 } ## end if ((substr $text, 0, ...
9343 =head3 Scalar, array, and hash completion: partially qualified package
9345 Much like the above, except we have to do a little more cleanup:
9349 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
9357 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
9361 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
9367 Figure out the prefix vs. what needs completing.
9371 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
9378 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
9384 map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
9392 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.
9396 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9397 return db_complete( $out[0], $line, $start );
9400 # Return the list of possibles.
9403 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
9409 =head3 Symbol completion: current package or package C<main>.
9413 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
9420 If it's C<main>, delete main to just get C<::> leading.
9424 $pack = ( $package eq 'main' ? '' : $package ) . '::';
9430 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
9434 $prefix = substr $text, 0, 1;
9435 $text = substr $text, 1;
9443 We look for the lexical scope above DB::DB and auto-complete lexical variables
9444 if PadWalker could be loaded.
9448 if (not $text =~ /::/ and eval {
9450 pop @INC if $INC[-1] eq '.';
9451 require PadWalker } ) {
9454 my @info = caller($level);
9458 last if $info[3] eq 'DB::DB';
9461 my $lexicals = PadWalker::peek_my($level);
9462 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
9470 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
9474 push @out, map "$prefix$_", grep /^\Q$text/,
9475 ( grep /^_?[a-zA-Z]/, do { no strict 'refs'; keys %$pack } ),
9476 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
9480 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
9486 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9487 return db_complete( $out[0], $line, $start );
9490 # Return the list of possibles.
9492 } ## end if ($text =~ /^[\$@%]/)
9496 We use C<option_val()> to look up the current value of the option. If there's
9497 only a single value, we complete the command in such a way that it is a
9498 complete command for setting the option in question. If there are multiple
9499 possible values, we generate a command consisting of the option plus a trailing
9500 question mark, which, if executed, will list the current value of the option.
9504 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
9505 { # Options after space
9506 # We look for the text to be matched in the list of possible options,
9507 # and fetch the current value.
9508 my @out = grep /^\Q$text/, @options;
9509 my $val = option_val( $out[0], undef );
9511 # Set up a 'query option's value' command.
9513 if ( not defined $val or $val =~ /[\n\r]/ ) {
9515 # There's really nothing else we can do.
9518 # We have a value. Create a proper option-setting command.
9519 elsif ( $val =~ /\s/ ) {
9521 # XXX This may be an extraneous variable.
9524 # We'll want to quote the string (because of the embedded
9525 # whtespace), but we want to make sure we don't end up with
9526 # mismatched quote characters. We try several possibilities.
9527 foreach my $l ( split //, qq/\"\'\#\|/ ) {
9529 # If we didn't find this quote character in the value,
9530 # quote it using this quote character.
9531 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
9533 } ## end elsif ($val =~ /\s/)
9535 # Don't need any quotes.
9540 # If there were multiple possible values, return '? ', which
9541 # makes the command into a query command. If there was just one,
9542 # have readline append that.
9543 $rl_attribs->{completer_terminator_character} =
9544 ( @out == 1 ? $out : '? ' );
9546 # Return list of possibilities.
9548 } ## end if ((substr $line, 0, ...
9550 =head3 Filename completion
9552 For entering filenames. We simply call C<readline>'s C<filename_list()>
9553 method with the completion text to get the possible completions.
9557 return $term->filename_list($text); # filenames
9559 } ## end sub db_complete
9561 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
9563 Functions that possibly ought to be somewhere else.
9573 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n";
9578 If we have $ini_pids, save it in the environment; else remove it from the
9579 environment. Used by the C<R> (restart) command.
9584 if ( defined($ini_pids) ) {
9585 $ENV{PERLDB_PIDS} = $ini_pids;
9588 delete( $ENV{PERLDB_PIDS} );
9590 } ## end sub clean_ENV
9592 # PERLDBf_... flag names from perl.h
9593 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
9596 %DollarCaretP_flags = (
9597 PERLDBf_SUB => 0x01, # Debug sub enter/exit
9598 PERLDBf_LINE => 0x02, # Keep line #
9599 PERLDBf_NOOPT => 0x04, # Switch off optimizations
9600 PERLDBf_INTER => 0x08, # Preserve more data
9601 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
9602 PERLDBf_SINGLE => 0x20, # Start with single-step on
9603 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
9604 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
9605 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
9606 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
9607 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
9608 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
9610 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
9611 # doesn't need to set it. It's provided for the benefit of profilers and
9612 # other code analysers.
9614 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
9617 sub parse_DollarCaretP_flags {
9622 foreach my $f ( split /\s*\|\s*/, $flags ) {
9624 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
9627 elsif ( $f =~ /^(\d+)$/ ) {
9630 elsif ( $f =~ /^DEFAULT$/i ) {
9631 $value = $DollarCaretP_flags{PERLDB_ALL};
9634 $f =~ /^(?:PERLDBf_)?(.*)$/i;
9635 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
9636 unless ( defined $value ) {
9638 "Unrecognized \$^P flag '$f'!\n",
9639 "Acceptable flags are: "
9640 . join( ', ', sort keys %DollarCaretP_flags ),
9641 ", and hexadecimal and decimal numbers.\n"
9651 sub expand_DollarCaretP_flags {
9652 my $DollarCaretP = shift;
9655 my $n = ( 1 << $_ );
9656 ( $DollarCaretP & $n )
9657 ? ( $DollarCaretP_flags_r{$n}
9658 || sprintf( '0x%x', $n ) )
9662 return @bits ? join( '|', @bits ) : 0;
9669 Rerun the current session to:
9671 rerun current position
9673 rerun 4 command number 4
9675 rerun -4 current command minus 4 (go back 4 steps)
9677 Whether this always makes sense, in the current context is unknowable, and is
9678 in part left as a useful exercise for the reader. This sub returns the
9679 appropriate arguments to rerun the current session.
9686 pop(@truehist); # strim
9687 unless (defined $truehist[$i]) {
9688 print "Unable to return to non-existent command: $i\n";
9690 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
9691 my @temp = @truehist; # store
9692 push(@DB::typeahead, @truehist); # saved
9693 @truehist = @hist = (); # flush
9694 @args = restart(); # setup
9695 get_list("PERLDB_HIST"); # clean
9696 set_list("PERLDB_HIST", @temp); # reset
9703 Restarting the debugger is a complex operation that occurs in several phases.
9704 First, we try to reconstruct the command line that was used to invoke Perl
9710 # I may not be able to resurrect you, but here goes ...
9712 "Warning: some settings and command-line options may be lost!\n";
9713 my ( @script, @flags, $cl );
9715 # If warn was on before, turn it on again.
9716 push @flags, '-w' if $ini_warn;
9718 # Rebuild the -I flags that were on the initial
9721 push @flags, '-I', $_;
9724 # Turn on taint if it was on before.
9725 push @flags, '-T' if ${^TAINT};
9727 # Arrange for setting the old INC:
9728 # Save the current @init_INC in the environment.
9729 set_list( "PERLDB_INC", @ini_INC );
9731 # If this was a perl one-liner, go to the "file"
9732 # corresponding to the one-liner read all the lines
9733 # out of it (except for the first one, which is going
9734 # to be added back on again when 'perl -d' runs: that's
9735 # the 'require perl5db.pl;' line), and add them back on
9736 # to the command line to be executed.
9738 my $lines = *{$main::{'_<-e'}}{ARRAY};
9739 for ( 1 .. $#$lines ) { # The first line is PERL5DB
9740 chomp( $cl = $lines->[$_] );
9741 push @script, '-e', $cl;
9743 } ## end if ($0 eq '-e')
9745 # Otherwise we just reuse the original name we had
9753 After the command line has been reconstructed, the next step is to save
9754 the debugger's status in environment variables. The C<DB::set_list> routine
9755 is used to save aggregate variables (both hashes and arrays); scalars are
9756 just popped into environment variables directly.
9760 # If the terminal supported history, grab it and
9761 # save that in the environment.
9762 set_list( "PERLDB_HIST",
9763 $term->Features->{getHistory}
9767 # Find all the files that were visited during this
9768 # session (i.e., the debugger had magic hashes
9769 # corresponding to them) and stick them in the environment.
9770 my @had_breakpoints = keys %had_breakpoints;
9771 set_list( "PERLDB_VISITED", @had_breakpoints );
9773 # Save the debugger options we chose.
9774 set_list( "PERLDB_OPT", %option );
9775 # set_list( "PERLDB_OPT", options2remember() );
9777 # Save the break-on-loads.
9778 set_list( "PERLDB_ON_LOAD", %break_on_load );
9782 The most complex part of this is the saving of all of the breakpoints. They
9783 can live in an awful lot of places, and we have to go through all of them,
9784 find the breakpoints, and then save them in the appropriate environment
9785 variable via C<DB::set_list>.
9789 # Go through all the breakpoints and make sure they're
9792 for ( 0 .. $#had_breakpoints ) {
9794 # We were in this file.
9795 my $file = $had_breakpoints[$_];
9797 # Grab that file's magic line hash.
9798 *dbline = $main::{ '_<' . $file };
9800 # Skip out if it doesn't exist, or if the breakpoint
9801 # is in a postponed file (we'll do postponed ones
9803 next unless %dbline or $postponed_file{$file};
9805 # In an eval. This is a little harder, so we'll
9806 # do more processing on that below.
9807 ( push @hard, $file ), next
9808 if $file =~ /^\(\w*eval/;
9810 # XXX I have no idea what this is doing. Yet.
9812 @add = %{ $postponed_file{$file} }
9813 if $postponed_file{$file};
9815 # Save the list of all the breakpoints for this file.
9816 set_list( "PERLDB_FILE_$_", %dbline, @add );
9818 # Serialize the extra data %breakpoints_data hash.
9820 set_list( "PERLDB_FILE_ENABLED_$_",
9821 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 }
9822 sort { $a <=> $b } keys(%dbline)
9824 } ## end for (0 .. $#had_breakpoints)
9826 # The breakpoint was inside an eval. This is a little
9827 # more difficult. XXX and I don't understand it.
9828 foreach my $hard_file (@hard) {
9829 # Get over to the eval in question.
9830 *dbline = $main::{ '_<' . $hard_file };
9831 my $quoted = quotemeta $hard_file;
9833 for my $sub ( keys %sub ) {
9834 if (my ($n1, $n2) = $sub{$sub} =~ /\A$quoted:(\d+)-(\d+)\z/) {
9835 $subs{$sub} = [ $n1, $n2 ];
9840 "No subroutines in $hard_file, ignoring breakpoints.\n";
9843 LINES: foreach my $line ( keys %dbline ) {
9845 # One breakpoint per sub only:
9846 my ( $offset, $found );
9847 SUBS: foreach my $sub ( keys %subs ) {
9849 $subs{$sub}->[1] >= $line # Not after the subroutine
9851 not defined $offset # Not caught
9857 $offset = $line - $subs{$sub}->[0];
9859 $offset = "+$offset";
9862 } ## end if ($subs{$sub}->[1] >=...
9863 } ## end for $sub (keys %subs)
9864 if ( defined $offset ) {
9865 $postponed{$found} =
9866 "break $offset if $dbline{$line}";
9870 ("Breakpoint in ${hard_file}:$line ignored:"
9871 . " after all the subroutines.\n");
9873 } ## end for $line (keys %dbline)
9874 } ## end for (@hard)
9876 # Save the other things that don't need to be
9878 set_list( "PERLDB_POSTPONE", %postponed );
9879 set_list( "PERLDB_PRETYPE", @$pretype );
9880 set_list( "PERLDB_PRE", @$pre );
9881 set_list( "PERLDB_POST", @$post );
9882 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9884 # We are officially restarting.
9885 $ENV{PERLDB_RESTART} = 1;
9887 # We are junking all child debuggers.
9888 delete $ENV{PERLDB_PIDS}; # Restore ini state
9890 # Set this back to the initial pid.
9891 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9895 After all the debugger status has been saved, we take the command we built up
9896 and then return it, so we can C<exec()> it. The debugger will spot the
9897 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9898 from the environment.
9902 # And run Perl again. Add the "-d" flag, all the
9903 # flags we built up, the script (whether a one-liner
9904 # or a file), add on the -emacs flag for a slave editor,
9905 # and then the old arguments.
9907 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9913 =head1 END PROCESSING - THE C<END> BLOCK
9915 Come here at the very end of processing. We want to go into a
9916 loop where we allow the user to enter commands and interact with the
9917 debugger, but we don't want anything else to execute.
9919 First we set the C<$finished> variable, so that some commands that
9920 shouldn't be run after the end of program quit working.
9922 We then figure out whether we're truly done (as in the user entered a C<q>
9923 command, or we finished execution while running nonstop). If we aren't,
9924 we set C<$single> to 1 (causing the debugger to get control again).
9926 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9927 message and returns control to the debugger. Repeat.
9929 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9930 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9931 break, run to completion.).
9936 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9937 $fall_off_end = 1 unless $inhibit_exit;
9939 # Do not stop in at_exit() and destructors on exit:
9940 if ($fall_off_end or $runnonstop) {
9944 DB::fake::at_exit();
9948 =head1 PRE-5.8 COMMANDS
9950 Some of the commands changed function quite a bit in the 5.8 command
9951 realignment, so much so that the old code had to be replaced completely.
9952 Because we wanted to retain the option of being able to go back to the
9953 former command set, we moved the old code off to this section.
9955 There's an awful lot of duplicated code here. We've duplicated the
9956 comments to keep things clear.
9960 Does nothing. Used to I<turn off> commands.
9964 sub cmd_pre580_null {
9969 =head2 Old C<a> command.
9971 This version added actions if you supplied them, and deleted them
9980 # Argument supplied. Add the action.
9981 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9983 # If the line isn't there, use the current line.
9984 my $i = $1 || $line;
9987 # If there is an action ...
9990 # ... but the line isn't breakable, skip it.
9991 if ( $dbline[$i] == 0 ) {
9992 print $OUT "Line $i may not have an action.\n";
9996 # ... and the line is breakable:
9997 # Mark that there's an action in this file.
9998 $had_breakpoints{$filename} |= 2;
10000 # Delete any current action.
10001 $dbline{$i} =~ s/\0[^\0]*//;
10003 # Add the new action, continuing the line as needed.
10004 $dbline{$i} .= "\0" . action($j);
10006 } ## end if (length $j)
10008 # No action supplied.
10011 # Delete the action.
10012 $dbline{$i} =~ s/\0[^\0]*//;
10014 # Mark as having no break or action if nothing's left.
10015 delete $dbline{$i} if $dbline{$i} eq '';
10017 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
10018 } ## end sub cmd_pre580_a
10020 =head2 Old C<b> command
10029 my $dbline = shift;
10032 if ( $cmd =~ /^load\b\s*(.*)/ ) {
10038 # b compile|postpone <some sub> [<condition>]
10039 # The interpreter actually traps this one for us; we just put the
10040 # necessary condition in the %postponed hash.
10041 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
10043 # Capture the condition if there is one. Make it true if none.
10044 my $cond = length $3 ? $3 : '1';
10046 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
10047 # if it was 'compile'.
10048 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
10050 # De-Perl4-ify the name - ' separators to ::.
10051 $subname =~ s/\'/::/g;
10053 # Qualify it into the current package unless it's already qualified.
10054 $subname = "${package}::" . $subname
10055 unless $subname =~ /::/;
10057 # Add main if it starts with ::.
10058 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
10060 # Save the break type for this sub.
10061 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
10062 } ## end elsif ($cmd =~ ...
10064 # b <sub name> [<condition>]
10065 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
10067 my $cond = length $2 ? $2 : '1';
10068 cmd_b_sub( $subname, $cond );
10070 # b <line> [<condition>].
10071 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
10072 my $i = $1 || $dbline;
10073 my $cond = length $2 ? $2 : '1';
10074 cmd_b_line( $i, $cond );
10076 } ## end sub cmd_pre580_b
10078 =head2 Old C<D> command.
10080 Delete all breakpoints unconditionally.
10087 if ( $cmd =~ /^\s*$/ ) {
10088 print $OUT "Deleting all breakpoints...\n";
10090 # %had_breakpoints lists every file that had at least one
10091 # breakpoint in it.
10093 for $file ( keys %had_breakpoints ) {
10095 # Switch to the desired file temporarily.
10096 local *dbline = $main::{ '_<' . $file };
10101 # For all lines in this file ...
10102 for my $i (1 .. $max) {
10104 # If there's a breakpoint or action on this line ...
10105 if ( defined $dbline{$i} ) {
10107 # ... remove the breakpoint.
10108 $dbline{$i} =~ s/^[^\0]+//;
10109 if ( $dbline{$i} =~ s/^\0?$// ) {
10111 # Remove the entry altogether if no action is there.
10112 delete $dbline{$i};
10114 } ## end if (defined $dbline{$i...
10115 } ## end for my $i (1 .. $max)
10117 # If, after we turn off the "there were breakpoints in this file"
10118 # bit, the entry in %had_breakpoints for this file is zero,
10119 # we should remove this file from the hash.
10120 if ( not $had_breakpoints{$file} &= ~1 ) {
10121 delete $had_breakpoints{$file};
10123 } ## end for $file (keys %had_breakpoints)
10125 # Kill off all the other breakpoints that are waiting for files that
10126 # haven't been loaded yet.
10128 undef %postponed_file;
10129 undef %break_on_load;
10130 } ## end if ($cmd =~ /^\s*$/)
10131 } ## end sub cmd_pre580_D
10133 =head2 Old C<h> command
10135 Print help. Defaults to printing the long-form help; the 5.8 version
10136 prints the summary by default.
10144 # Print the *right* help, long format.
10145 if ( $cmd =~ /^\s*$/ ) {
10146 print_help($pre580_help);
10149 # 'h h' - explicitly-requested summary.
10150 elsif ( $cmd =~ /^h\s*/ ) {
10151 print_help($pre580_summary);
10154 # Find and print a command's help.
10155 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
10156 my $asked = $1; # for proper errmsg
10157 my $qasked = quotemeta($asked); # for searching
10158 # XXX: finds CR but not <CR>
10162 (?:[IB]<) # Optional markup
10163 $qasked # The command name
10170 ( # The command help:
10172 (?:[IB]<) # Optional markup
10173 $qasked # The command name
10174 ([\s\S]*?) # Lines starting with tabs
10178 ) # Line not starting with space
10179 # (Next command's help)
10183 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
10187 print_help("B<$asked> is not a debugger command.\n");
10189 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
10190 } ## end sub cmd_pre580_h
10192 =head2 Old C<W> command
10194 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
10202 # Delete all watch expressions.
10203 if ( $cmd =~ /^$/ ) {
10205 # No watching is going on.
10208 # Kill all the watch expressions and values.
10209 @to_watch = @old_watch = ();
10212 # Add a watch expression.
10213 elsif ( $cmd =~ /^(.*)/s ) {
10215 # add it to the list to be watched.
10216 push @to_watch, $1;
10218 # Get the current value of the expression.
10219 # Doesn't handle expressions returning list values!
10221 # The &-call is here to ascertain the mutability of @_.
10222 my ($val) = &DB::eval;
10223 $val = ( defined $val ) ? "'$val'" : 'undef';
10226 push @old_watch, $val;
10228 # We're watching stuff.
10231 } ## end elsif ($cmd =~ /^(.*)/s)
10232 } ## end sub cmd_pre580_W
10234 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
10236 The debugger used to have a bunch of nearly-identical code to handle
10237 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
10238 C<cmd_prepost> unify all this into one set of code to handle the
10239 appropriate actions.
10241 =head2 C<cmd_pre590_prepost>
10243 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
10244 do something destructive. In pre 5.8 debuggers, the default action was to
10245 delete all the actions.
10249 sub cmd_pre590_prepost {
10251 my $line = shift || '*';
10252 my $dbline = shift;
10254 return cmd_prepost( $cmd, $line, $dbline );
10255 } ## end sub cmd_pre590_prepost
10257 =head2 C<cmd_prepost>
10259 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
10260 Since the lists of actions are all held in arrays that are pointed to by
10261 references anyway, all we have to do is pick the right array reference and
10262 then use generic code to all, delete, or list actions.
10269 # No action supplied defaults to 'list'.
10270 my $line = shift || '?';
10272 # Figure out what to put in the prompt.
10275 # Make sure we have some array or another to address later.
10276 # This means that if for some reason the tests fail, we won't be
10277 # trying to stash actions or delete them from the wrong place.
10280 # < - Perl code to run before prompt.
10281 if ( $cmd =~ /^\</o ) {
10282 $which = 'pre-perl';
10286 # > - Perl code to run after prompt.
10287 elsif ( $cmd =~ /^\>/o ) {
10288 $which = 'post-perl';
10292 # { - first check for properly-balanced braces.
10293 elsif ( $cmd =~ /^\{/o ) {
10294 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
10296 "$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n";
10299 # Properly balanced. Pre-prompt debugger actions.
10301 $which = 'pre-debugger';
10304 } ## end elsif ( $cmd =~ /^\{/o )
10306 # Did we find something that makes sense?
10308 print $OUT "Confused by command: $cmd\n";
10315 if ( $line =~ /^\s*\?\s*$/o ) {
10318 # Nothing there. Complain.
10319 print $OUT "No $which actions.\n";
10323 # List the actions in the selected list.
10324 print $OUT "$which commands:\n";
10325 foreach my $action (@$aref) {
10326 print $OUT "\t$cmd -- $action\n";
10329 } ## end if ( $line =~ /^\s*\?\s*$/o)
10331 # Might be a delete.
10333 if ( length($cmd) == 1 ) {
10334 if ( $line =~ /^\s*\*\s*$/o ) {
10336 # It's a delete. Get rid of the old actions in the
10339 print $OUT "All $cmd actions cleared.\n";
10343 # Replace all the actions. (This is a <, >, or {).
10344 @$aref = action($line);
10346 } ## end if ( length($cmd) == 1)
10347 elsif ( length($cmd) == 2 ) {
10349 # Add the action to the line. (This is a <<, >>, or {{).
10350 push @$aref, action($line);
10354 # <<<, >>>>, {{{{{{ ... something not a command.
10356 "Confused by strange length of $which command($cmd)...\n";
10358 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
10360 } ## end sub cmd_prepost
10364 Contains the C<at_exit> routine that the debugger uses to issue the
10365 C<Debugged program terminated ...> message after the program completes. See
10366 the C<END> block documentation for more details.
10373 "Debugged program terminated. Use 'q' to quit or 'R' to restart.";
10376 package DB; # Do not trace this 1; below!