4 perl5db.pl - the perl debugger
8 perl -d your_Perl_script
12 C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
13 you invoke a script with C<perl -d>. This documentation tries to outline the
14 structure and services provided by C<perl5db.pl>, and to describe how you
19 The debugger can look pretty forbidding to many Perl programmers. There are
20 a number of reasons for this, many stemming out of the debugger's history.
22 When the debugger was first written, Perl didn't have a lot of its nicer
23 features - no references, no lexical variables, no closures, no object-oriented
24 programming. So a lot of the things one would normally have done using such
25 features was done using global variables, globs and the C<local()> operator
28 Some of these have survived into the current debugger; a few of the more
29 interesting and still-useful idioms are noted in this section, along with notes
30 on the comments themselves.
32 =head2 Why not use more lexicals?
34 Experienced Perl programmers will note that the debugger code tends to use
35 mostly package globals rather than lexically-scoped variables. This is done
36 to allow a significant amount of control of the debugger from outside the
39 Unfortunately, though the variables are accessible, they're not well
40 documented, so it's generally been a decision that hasn't made a lot of
41 difference to most users. Where appropriate, comments have been added to
42 make variables more accessible and usable, with the understanding that these
43 I<are> debugger internals, and are therefore subject to change. Future
44 development should probably attempt to replace the globals with a well-defined
45 API, but for now, the variables are what we've got.
47 =head2 Automated variable stacking via C<local()>
49 As you may recall from reading C<perlfunc>, the C<local()> operator makes a
50 temporary copy of a variable in the current scope. When the scope ends, the
51 old copy is restored. This is often used in the debugger to handle the
52 automatic stacking of variables during recursive calls:
57 # Do some stuff, then ...
61 What happens is that on entry to the subroutine, C<$some_global> is localized,
62 then altered. When the subroutine returns, Perl automatically undoes the
63 localization, restoring the previous value. Voila, automatic stack management.
65 The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
66 which lets the debugger get control inside of C<eval>'ed code. The debugger
67 localizes a saved copy of C<$@> inside the subroutine, which allows it to
68 keep C<$@> safe until it C<DB::eval> returns, at which point the previous
69 value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
70 track of C<$@> inside C<eval>s which C<eval> other C<eval's>.
72 In any case, watch for this pattern. It occurs fairly often.
76 This is used to cleverly reverse the sense of a logical test depending on
77 the value of an auxiliary variable. For instance, the debugger's C<S>
78 (search for subroutines by pattern) allows you to negate the pattern
81 # Find all non-'foo' subs:
84 Boolean algebra states that the truth table for XOR looks like this:
90 (! not present and no match) --> false, don't print
94 (! not present and matches) --> true, print
98 (! present and no match) --> true, print
102 (! present and matches) --> false, don't print
106 As you can see, the first pair applies when C<!> isn't supplied, and
107 the second pair applies when it is. The XOR simply allows us to
108 compact a more complicated if-then-elseif-else into a more elegant
109 (but perhaps overly clever) single test. After all, it needed this
112 =head2 FLAGS, FLAGS, FLAGS
114 There is a certain C programming legacy in the debugger. Some variables,
115 such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed
116 of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
117 of state to be stored independently in a single scalar.
123 is checking to see if the appropriate bit is on. Since each bit can be
124 "addressed" independently in this way, C<$scalar> is acting sort of like
125 an array of bits. Obviously, since the contents of C<$scalar> are just a
126 bit-pattern, we can save and restore it easily (it will just look like
129 The problem, is of course, that this tends to leave magic numbers scattered
130 all over your program whenever a bit is set, cleared, or checked. So why do
137 First, doing an arithmetical or bitwise operation on a scalar is
138 just about the fastest thing you can do in Perl: C<use constant> actually
139 creates a subroutine call, and array and hash lookups are much slower. Is
140 this over-optimization at the expense of readability? Possibly, but the
141 debugger accesses these variables a I<lot>. Any rewrite of the code will
142 probably have to benchmark alternate implementations and see which is the
143 best balance of readability and speed, and then document how it actually
148 Second, it's very easy to serialize a scalar number. This is done in
149 the restart code; the debugger state variables are saved in C<%ENV> and then
150 restored when the debugger is restarted. Having them be just numbers makes
155 Third, some of these variables are being shared with the Perl core
156 smack in the middle of the interpreter's execution loop. It's much faster for
157 a C program (like the interpreter) to check a bit in a scalar than to access
158 several different variables (or a Perl array).
162 =head2 What are those C<XXX> comments for?
164 Any comment containing C<XXX> means that the comment is either somewhat
165 speculative - it's not exactly clear what a given variable or chunk of
166 code is doing, or that it is incomplete - the basics may be clear, but the
167 subtleties are not completely documented.
169 Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
171 =head1 DATA STRUCTURES MAINTAINED BY CORE
173 There are a number of special data structures provided to the debugger by
174 the Perl interpreter.
176 The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline>
177 via glob assignment) contains the text from C<$filename>, with each
178 element corresponding to a single line of C<$filename>. Additionally,
179 breakable lines will be dualvars with the numeric component being the
180 memory address of a COP node. Non-breakable lines are dualvar to 0.
182 The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
183 assignment) contains breakpoints and actions. The keys are line numbers;
184 you can set individual values, but not the whole hash. The Perl interpreter
185 uses this hash to determine where breakpoints have been set. Any true value is
186 considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
187 Values are magical in numeric context: 1 if the line is breakable, 0 if not.
189 The scalar C<${"_<$filename"}> simply contains the string C<$filename>.
190 This is also the case for evaluated strings that contain subroutines, or
191 which are currently being executed. The $filename for C<eval>ed strings looks
194 =head1 DEBUGGER STARTUP
196 When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
197 non-interactive sessions, C<.perldb> for interactive ones) that can set a number
198 of options. In addition, this file may define a subroutine C<&afterinit>
199 that will be executed (in the debugger's context) after the debugger has
202 Next, it checks the C<PERLDB_OPTS> environment variable and treats its
203 contents as the argument of a C<o> command in the debugger.
205 =head2 STARTUP-ONLY OPTIONS
207 The following options can only be specified at startup.
208 To set them in your rcfile, add a call to
209 C<&parse_options("optionName=new_value")>.
215 the TTY to use for debugging i/o.
219 if set, goes in NonStop mode. On interrupt, if TTY is not set,
220 uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
221 Term::Rendezvous. Current variant is to have the name of TTY in this
226 if false, a dummy ReadLine is used, so you can debug
227 ReadLine applications.
231 if true, no i/o is performed until interrupt.
235 file or pipe to print line number info to. If it is a
236 pipe, a short "emacs like" message is used.
240 host:port to connect to on remote host for remote debugging.
244 file to store session history to. There is no default and so no
245 history file is written unless this variable is explicitly set.
249 number of commands to store to the file specified in C<HistFile>.
256 &parse_options("NonStop=1 LineInfo=db.out");
257 sub afterinit { $trace = 1; }
259 The script will run without human intervention, putting trace
260 information into C<db.out>. (If you interrupt it, you had better
261 reset C<LineInfo> to something I<interactive>!)
263 =head1 INTERNALS DESCRIPTION
265 =head2 DEBUGGER INTERFACE VARIABLES
267 Perl supplies the values for C<%sub>. It effectively inserts
268 a C<&DB::DB();> in front of each place that can have a
269 breakpoint. At each subroutine call, it calls C<&DB::sub> with
270 C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
271 {require 'perl5db.pl'}> before the first line.
273 After each C<require>d file is compiled, but before it is executed, a
274 call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
275 is the expanded name of the C<require>d file (as found via C<%INC>).
277 =head3 IMPORTANT INTERNAL VARIABLES
281 Used to control when the debugger will attempt to acquire another TTY to be
286 =item * 1 - on C<fork()>
288 =item * 2 - debugger is started inside debugger
290 =item * 4 - on startup
296 The value -2 indicates that no return value should be printed.
297 Any other positive value causes C<DB::sub> to print return values.
301 The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
302 contents of C<@_> when C<DB::eval> is called.
306 Determines what messages (if any) will get printed when a subroutine (or eval)
307 is entered or exited.
311 =item * 0 - No enter/exit messages
313 =item * 1 - Print I<entering> messages on subroutine entry
315 =item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
317 =item * 4 - Extended messages: C<< <in|out> I<context>=I<fully-qualified sub name> from I<file>:I<line> >>. If no other flag is on, acts like 1+4.
319 =item * 8 - Adds parameter information to messages, and overloaded stringify and tied FETCH is enabled on the printed arguments. Ignored if C<4> is not on.
321 =item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is is not on.
325 To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
326 The debugger internally juggles the value of C<$frame> during execution to
327 protect external modules that the debugger uses from getting traced.
331 Tracks current debugger nesting level. Used to figure out how many
332 C<E<lt>E<gt>> pairs to surround the line number with when the debugger
333 outputs a prompt. Also used to help determine if the program has finished
334 during command parsing.
336 =head4 C<$onetimeDump>
338 Controls what (if anything) C<DB::eval()> will print after evaluating an
343 =item * C<undef> - don't print anything
345 =item * C<dump> - use C<dumpvar.pl> to display the value returned
347 =item * C<methods> - print the methods callable on the first item returned
351 =head4 C<$onetimeDumpDepth>
353 Controls how far down C<dumpvar.pl> will go before printing C<...> while
354 dumping a structure. Numeric. If C<undef>, print all levels.
358 Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
359 which is called before every statement, checks this and puts the user into
360 command mode if it finds C<$signal> set to a true value.
364 Controls behavior during single-stepping. Stacked in C<@stack> on entry to
365 each subroutine; popped again at the end of each subroutine.
369 =item * 0 - run continuously.
371 =item * 1 - single-step, go into subs. The C<s> command.
373 =item * 2 - single-step, don't go into subs. The C<n> command.
375 =item * 4 - print current sub depth (turned on to force this when C<too much
382 Controls the output of trace information.
386 =item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
388 =item * 2 - watch expressions are active
390 =item * 4 - user defined a C<watchfunction()> in C<afterinit()>
394 =head4 C<$slave_editor>
396 1 if C<LINEINFO> was directed to a pipe; 0 otherwise.
400 Stack of filehandles that C<DB::readline()> will read commands from.
401 Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
405 Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
406 supplied by the Perl interpreter to the debugger. Contains the source.
410 Previous values of watch expressions. First set when the expression is
411 entered; reset whenever the watch expression changes.
415 Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
416 so that the debugger can substitute safe values while it's running, and
417 restore them when it returns control.
421 Saves the current value of C<$single> on entry to a subroutine.
422 Manipulated by the C<c> command to turn off tracing in all subs above the
427 The 'watch' expressions: to be evaluated before each line is executed.
431 The typeahead buffer, used by C<DB::readline>.
435 Command aliases. Stored as character strings to be substituted for a command
438 =head4 C<%break_on_load>
440 Keys are file names, values are 1 (break when this file is loaded) or undef
441 (don't break when it is loaded).
445 Keys are line numbers, values are C<condition\0action>. If used in numeric
446 context, values are 0 if not breakable, 1 if breakable, no matter what is
447 in the actual hash entry.
449 =head4 C<%had_breakpoints>
451 Keys are file names; values are bitfields:
455 =item * 1 - file has a breakpoint in it.
457 =item * 2 - file has an action in it.
461 A zero or undefined value means this file has neither.
465 Stores the debugger options. These are character string values.
469 Saves breakpoints for code that hasn't been compiled yet.
470 Keys are subroutine names, values are:
474 =item * C<compile> - break when this sub is compiled
476 =item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
480 =head4 C<%postponed_file>
482 This hash keeps track of breakpoints that need to be set for files that have
483 not yet been compiled. Keys are filenames; values are references to hashes.
484 Each of these hashes is keyed by line number, and its values are breakpoint
485 definitions (C<condition\0action>).
487 =head1 DEBUGGER INITIALIZATION
489 The debugger's initialization actually jumps all over the place inside this
490 package. This is because there are several BEGIN blocks (which of course
491 execute immediately) spread through the code. Why is that?
493 The debugger needs to be able to change some things and set some things up
494 before the debugger code is compiled; most notably, the C<$deep> variable that
495 C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
496 debugger has to turn off warnings while the debugger code is compiled, but then
497 restore them to their original setting before the program being debugged begins
500 The first C<BEGIN> block simply turns off warnings by saving the current
501 setting of C<$^W> and then setting it to zero. The second one initializes
502 the debugger variables that are needed before the debugger begins executing.
503 The third one puts C<$^X> back to its former value.
505 We'll detail the second C<BEGIN> block later; just remember that if you need
506 to initialize something before the debugger starts really executing, that's
515 BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
519 $^V =~ /^v(\d+\.\d+)/;
520 feature->import(":$1");
523 # Debugger for Perl 5.00x; perl5db.pl patch level:
524 use vars qw($VERSION $header);
526 $VERSION = '1.39_05';
528 $header = "perl5db.pl version $VERSION";
530 =head1 DEBUGGER ROUTINES
534 This function replaces straight C<eval()> inside the debugger; it simplifies
535 the process of evaluating code in the user's context.
537 The code to be evaluated is passed via the package global variable
538 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
540 Before we do the C<eval()>, we preserve the current settings of C<$trace>,
541 C<$single>, C<$^D> and C<$usercontext>. The latter contains the
542 preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
543 user's current package, grabbed when C<DB::DB> got control. This causes the
544 proper context to be used when the eval is actually done. Afterward, we
545 restore C<$trace>, C<$single>, and C<$^D>.
547 Next we need to handle C<$@> without getting confused. We save C<$@> in a
548 local lexical, localize C<$saved[0]> (which is where C<save()> will put
549 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
550 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
551 considered sane by the debugger. If there was an C<eval()> error, we print
552 it on the debugger's output. If C<$onetimedump> is defined, we call
553 C<dumpit> if it's set to 'dump', or C<methods> if it's set to
554 'methods'. Setting it to something else causes the debugger to do the eval
555 but not print the result - handy if you want to do something else with it
556 (the "watch expressions" code does this to get the value of the watch
557 expression but not show it unless it matters).
559 In any case, we then return the list of output from C<eval> to the caller,
560 and unwinding restores the former version of C<$@> in C<@saved> as well
561 (the localization of C<$saved[0]> goes away at the end of this scope).
563 =head3 Parameters and variables influencing execution of DB::eval()
565 C<DB::eval> isn't parameterized in the standard way; this is to keep the
566 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
567 The variables listed below influence C<DB::eval()>'s execution directly.
571 =item C<$evalarg> - the thing to actually be eval'ed
573 =item C<$trace> - Current state of execution tracing
575 =item C<$single> - Current state of single-stepping
577 =item C<$onetimeDump> - what is to be displayed after the evaluation
579 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
583 The following variables are altered by C<DB::eval()> during its execution. They
584 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
588 =item C<@res> - used to capture output from actual C<eval>.
590 =item C<$otrace> - saved value of C<$trace>.
592 =item C<$osingle> - saved value of C<$single>.
594 =item C<$od> - saved value of C<$^D>.
596 =item C<$saved[0]> - saved value of C<$@>.
598 =item $\ - for output of C<$@> if there is an evaluation error.
602 =head3 The problem of lexicals
604 The context of C<DB::eval()> presents us with some problems. Obviously,
605 we want to be 'sandboxed' away from the debugger's internals when we do
606 the eval, but we need some way to control how punctuation variables and
607 debugger globals are used.
609 We can't use local, because the code inside C<DB::eval> can see localized
610 variables; and we can't use C<my> either for the same reason. The code
611 in this routine compromises and uses C<my>.
613 After this routine is over, we don't have user code executing in the debugger's
614 context, so we can use C<my> freely.
618 ############################################## Begin lexical danger zone
620 # 'my' variables used here could leak into (that is, be visible in)
621 # the context that the code being evaluated is executing in. This means that
622 # the code could modify the debugger's variables.
624 # Fiddling with the debugger's context could be Bad. We insulate things as
689 # Used to save @ARGV and extract any debugger-related flags.
692 # Used to prevent multiple entries to diesignal()
693 # (if for instance diesignal() itself dies)
696 # Used to prevent the debugger from running nonstop
700 sub _calc_usercontext {
703 # Cancel strict completely for the evaluated code, so the code
704 # the user evaluates won't be affected by it. (Shlomi Fish)
705 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
706 . "package $package;"; # this won't let them modify, alas
711 # 'my' would make it visible from user code
712 # but so does local! --tchrist
713 # Remember: this localizes @DB::res, not @main::res.
717 # Try to keep the user code from messing with us. Save these so that
718 # even if the eval'ed code changes them, we can put them back again.
719 # Needed because the user could refer directly to the debugger's
720 # package globals (and any 'my' variables in this containing scope)
721 # inside the eval(), and we want to try to stay safe.
722 local $otrace = $trace;
723 local $osingle = $single;
726 # Untaint the incoming eval() argument.
727 { ($evalarg) = $evalarg =~ /(.*)/s; }
729 # $usercontext built in DB::DB near the comment
730 # "set up the context for DB::eval ..."
731 # Evaluate and save any results.
732 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
734 # Restore those old values.
740 # Save the current value of $@, and preserve it in the debugger's copy
741 # of the saved precious globals.
744 # Since we're only saving $@, we only have to localize the array element
745 # that it will be stored in.
746 local $saved[0]; # Preserve the old value of $@
749 # Now see whether we need to report an error back to the user.
755 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
756 # are package globals.
757 elsif ($onetimeDump) {
758 if ( $onetimeDump eq 'dump' ) {
759 local $option{dumpDepth} = $onetimedumpDepth
760 if defined $onetimedumpDepth;
761 dumpit( $OUT, \@res );
763 elsif ( $onetimeDump eq 'methods' ) {
766 } ## end elsif ($onetimeDump)
770 ############################################## End lexical danger zone
772 # After this point it is safe to introduce lexicals.
773 # The code being debugged will be executing in its own context, and
774 # can't see the inside of the debugger.
776 # However, one should not overdo it: leave as much control from outside as
777 # possible. If you make something a lexical, it's not going to be addressable
778 # from outside the debugger even if you know its name.
780 # This file is automatically included if you do perl -d.
781 # It's probably not useful to include this yourself.
783 # Before venturing further into these twisty passages, it is
784 # wise to read the perldebguts man page or risk the ire of dragons.
786 # (It should be noted that perldebguts will tell you a lot about
787 # the underlying mechanics of how the debugger interfaces into the
788 # Perl interpreter, but not a lot about the debugger itself. The new
789 # comments in this code try to address this problem.)
791 # Note that no subroutine call is possible until &DB::sub is defined
792 # (for subroutines defined outside of the package DB). In fact the same is
793 # true if $deep is not defined.
795 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
797 # modified Perl debugger, to be run from Emacs in perldb-mode
798 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
799 # Johan Vromans -- upgrade to 4.0 pl 10
800 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
801 ########################################################################
803 =head1 DEBUGGER INITIALIZATION
805 The debugger starts up in phases.
809 First, it initializes the environment it wants to run in: turning off
810 warnings during its own compilation, defining variables which it will need
811 to avoid warnings later, setting itself up to not exit when the program
812 terminates, and defaulting to printing return values for the C<r> command.
816 # Needed for the statement after exec():
818 # This BEGIN block is simply used to switch off warnings during debugger
819 # compilation. Probably it would be better practice to fix the warnings,
820 # but this is how it's done at the moment.
825 } # Switch compilation warnings off until another BEGIN.
827 local ($^W) = 0; # Switch run-time warnings off during init.
829 =head2 THREADS SUPPORT
831 If we are running under a threaded Perl, we require threads and threads::shared
832 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
833 threaded debugger control. C<-dt> can also be used to set this.
835 Each new thread will be announced and the debugger prompt will always inform
836 you of each new thread created. It will also indicate the thread id in which
837 we are currently running within the prompt like this:
841 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
842 command prompt. The prompt will show: C<[0]> when running under threads, but
843 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
845 While running under threads, when you set or delete a breakpoint (etc.), this
846 will apply to all threads, not just the currently running one. When you are
847 in a currently executing thread, you will stay there until it completes. With
848 the current implementation it is not currently possible to hop from one thread
851 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
853 Note that threading support was built into the debugger as of Perl version
854 C<5.8.6> and debugger version C<1.2.8>.
859 # ensure we can share our non-threaded variables or no-op
860 if ($ENV{PERL5DB_THREADED}) {
862 require threads::shared;
863 import threads::shared qw(share);
867 print "Threads support enabled\n";
869 *share = sub(\[$@%]) {};
873 # These variables control the execution of 'dumpvar.pl'.
888 # used to control die() reporting in diesignal()
891 use vars qw($CarpLevel);
894 # without threads, $filename is not defined until DB::DB is called
895 share($main::{'_<'.$filename}) if defined $filename;
897 # Command-line + PERLLIB:
898 # Save the contents of @INC before they are modified elsewhere.
901 # This was an attempt to clear out the previous values of various
902 # trapped errors. Apparently it didn't help. XXX More info needed!
903 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
905 # We set these variables to safe values. We don't want to blindly turn
906 # off warnings, because other packages may still want them.
907 $trace = $signal = $single = 0; # Uninitialized warning suppression
908 # (local $^W cannot help - other packages!).
910 # Default to not exiting when program finishes; print the return
911 # value when the 'r' command is used to return from a subroutine.
912 $inhibit_exit = $option{PrintRet} = 1;
914 use vars qw($trace_to_depth);
916 # Default to 1E9 so it won't be limited to a certain recursion depth.
917 $trace_to_depth = 1E9;
919 =head1 OPTION PROCESSING
921 The debugger's options are actually spread out over the debugger itself and
922 C<dumpvar.pl>; some of these are variables to be set, while others are
923 subs to be called with a value. To try to make this a little easier to
924 manage, the debugger uses a few data structures to define what options
925 are legal and how they are to be processed.
927 First, the C<@options> array defines the I<names> of all the options that
933 CommandSet HistFile HistSize
934 hashDepth arrayDepth dumpDepth
935 DumpDBFiles DumpPackages DumpReused
936 compactDump veryCompact quote
937 HighBit undefPrint globPrint
938 PrintRet UsageOnly frame
940 ReadLine NonStop LineInfo
941 maxTraceLen recallCommand ShellBang
942 pager tkRunning ornaments
943 signalLevel warnLevel dieLevel
944 inhibit_exit ImmediateStop bareStringify
945 CreateTTY RemotePort windowSize
949 @RememberOnROptions = qw(DollarCaretP);
953 Second, C<optionVars> lists the variables that each option uses to save its
958 use vars qw(%optionVars);
961 hashDepth => \$dumpvar::hashDepth,
962 arrayDepth => \$dumpvar::arrayDepth,
963 CommandSet => \$CommandSet,
964 DumpDBFiles => \$dumpvar::dumpDBFiles,
965 DumpPackages => \$dumpvar::dumpPackages,
966 DumpReused => \$dumpvar::dumpReused,
967 HighBit => \$dumpvar::quoteHighBit,
968 undefPrint => \$dumpvar::printUndef,
969 globPrint => \$dumpvar::globPrint,
970 UsageOnly => \$dumpvar::usageOnly,
971 CreateTTY => \$CreateTTY,
972 bareStringify => \$dumpvar::bareStringify,
974 AutoTrace => \$trace,
975 inhibit_exit => \$inhibit_exit,
976 maxTraceLen => \$maxtrace,
977 ImmediateStop => \$ImmediateStop,
978 RemotePort => \$remoteport,
979 windowSize => \$window,
980 HistFile => \$histfile,
981 HistSize => \$histsize,
986 Third, C<%optionAction> defines the subroutine to be called to process each
991 use vars qw(%optionAction);
994 compactDump => \&dumpvar::compactDump,
995 veryCompact => \&dumpvar::veryCompact,
996 quote => \&dumpvar::quote,
999 ReadLine => \&ReadLine,
1000 NonStop => \&NonStop,
1001 LineInfo => \&LineInfo,
1002 recallCommand => \&recallCommand,
1003 ShellBang => \&shellBang,
1005 signalLevel => \&signalLevel,
1006 warnLevel => \&warnLevel,
1007 dieLevel => \&dieLevel,
1008 tkRunning => \&tkRunning,
1009 ornaments => \&ornaments,
1010 RemotePort => \&RemotePort,
1011 DollarCaretP => \&DollarCaretP,
1016 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1021 # Note that this list is not complete: several options not listed here
1022 # actually require that dumpvar.pl be loaded for them to work, but are
1023 # not in the table. A subsequent patch will correct this problem; for
1024 # the moment, we're just recommenting, and we are NOT going to change
1026 use vars qw(%optionRequire);
1029 compactDump => 'dumpvar.pl',
1030 veryCompact => 'dumpvar.pl',
1031 quote => 'dumpvar.pl',
1036 There are a number of initialization-related variables which can be set
1037 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1038 variable. These are:
1042 =item C<$rl> - readline control XXX needs more explanation
1044 =item C<$warnLevel> - whether or not debugger takes over warning handling
1046 =item C<$dieLevel> - whether or not debugger takes over die handling
1048 =item C<$signalLevel> - whether or not debugger takes over signal handling
1050 =item C<$pre> - preprompt actions (array reference)
1052 =item C<$post> - postprompt actions (array reference)
1056 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1058 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1064 # These guys may be defined in $ENV{PERL5DB} :
1065 $rl = 1 unless defined $rl;
1066 $warnLevel = 1 unless defined $warnLevel;
1067 $dieLevel = 1 unless defined $dieLevel;
1068 $signalLevel = 1 unless defined $signalLevel;
1069 $pre = [] unless defined $pre;
1070 $post = [] unless defined $post;
1071 $pretype = [] unless defined $pretype;
1072 $CreateTTY = 3 unless defined $CreateTTY;
1073 $CommandSet = '580' unless defined $CommandSet;
1078 share($signalLevel);
1088 The default C<die>, C<warn>, and C<signal> handlers are set up.
1092 warnLevel($warnLevel);
1093 dieLevel($dieLevel);
1094 signalLevel($signalLevel);
1098 The pager to be used is needed next. We try to get it from the
1099 environment first. If it's not defined there, we try to find it in
1100 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1101 then call the C<pager()> function to save the pager name.
1105 # This routine makes sure $pager is set up so that '|' can use it.
1108 # If PAGER is defined in the environment, use it.
1112 # If not, see if Config.pm defines it.
1113 : eval { require Config }
1114 && defined $Config::Config{pager}
1115 ? $Config::Config{pager}
1117 # If not, fall back to 'more'.
1120 unless defined $pager;
1124 We set up the command to be used to access the man pages, the command
1125 recall character (C<!> unless otherwise defined) and the shell escape
1126 character (C<!> unless otherwise defined). Yes, these do conflict, and
1127 neither works in the debugger at the moment.
1133 # Set up defaults for command recall and shell escape (note:
1134 # these currently don't work in linemode debugging).
1135 recallCommand("!") unless defined $prc;
1136 shellBang("!") unless defined $psh;
1140 We then set up the gigantic string containing the debugger help.
1141 We also set the limit on the number of arguments we'll display during a
1148 # If we didn't get a default for the length of eval/stack trace args,
1150 $maxtrace = 400 unless defined $maxtrace;
1152 =head2 SETTING UP THE DEBUGGER GREETING
1154 The debugger I<greeting> helps to inform the user how many debuggers are
1155 running, and whether the current debugger is the primary or a child.
1157 If we are the primary, we just hang onto our pid so we'll have it when
1158 or if we start a child debugger. If we are a child, we'll set things up
1159 so we'll have a unique greeting and so the parent will give us our own
1162 We save the current contents of the C<PERLDB_PIDS> environment variable
1163 because we mess around with it. We'll also need to hang onto it because
1164 we'll need it if we restart.
1166 Child debuggers make a label out of the current PID structure recorded in
1167 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1168 yet so the parent will give them one later via C<resetterm()>.
1172 # Save the current contents of the environment; we're about to
1173 # much with it. We'll need this if we have to restart.
1174 use vars qw($ini_pids);
1175 $ini_pids = $ENV{PERLDB_PIDS};
1177 use vars qw ($pids $term_pid);
1179 if ( defined $ENV{PERLDB_PIDS} ) {
1181 # We're a child. Make us a label out of the current PID structure
1182 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1183 # a term yet so the parent will give us one later via resetterm().
1185 my $env_pids = $ENV{PERLDB_PIDS};
1186 $pids = "[$env_pids]";
1188 # Unless we are on OpenVMS, all programs under the DCL shell run under
1191 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1195 $ENV{PERLDB_PIDS} .= "->$$";
1199 } ## end if (defined $ENV{PERLDB_PIDS...
1202 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1203 # child debugger, and mark us as the parent, so we'll know to set up
1204 # more TTY's is we have to.
1205 $ENV{PERLDB_PIDS} = "$$";
1210 use vars qw($pidprompt);
1213 # Sets up $emacs as a synonym for $slave_editor.
1214 our ($slave_editor);
1215 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1217 =head2 READING THE RC FILE
1219 The debugger will read a file of initialization options if supplied. If
1220 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1224 # As noted, this test really doesn't check accurately that the debugger
1225 # is running at a terminal or not.
1227 use vars qw($rcfile);
1229 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1230 # this is the wrong metric!
1231 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
1236 The debugger does a safety test of the file to be read. It must be owned
1237 either by the current user or root, and must only be writable by the owner.
1241 # This wraps a safety test around "do" to read and evaluate the init file.
1243 # This isn't really safe, because there's a race
1244 # between checking and opening. The solution is to
1245 # open and fstat the handle, but then you have to read and
1246 # eval the contents. But then the silly thing gets
1247 # your lexical scope, which is unfortunate at best.
1251 # Just exactly what part of the word "CORE::" don't you understand?
1252 local $SIG{__WARN__};
1253 local $SIG{__DIE__};
1255 unless ( is_safe_file($file) ) {
1256 CORE::warn <<EO_GRIPE;
1257 perldb: Must not source insecure rcfile $file.
1258 You or the superuser must be the owner, and it must not
1259 be writable by anyone but its owner.
1262 } ## end unless (is_safe_file($file...
1265 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1266 } ## end sub safe_do
1268 # This is the safety test itself.
1270 # Verifies that owner is either real user or superuser and that no
1271 # one but owner may write to it. This function is of limited use
1272 # when called on a path instead of upon a handle, because there are
1273 # no guarantees that filename (by dirent) whose file (by ino) is
1274 # eventually accessed is the same as the one tested.
1275 # Assumes that the file's existence is not in doubt.
1278 stat($path) || return; # mysteriously vaporized
1279 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1281 return 0 if $uid != 0 && $uid != $<;
1282 return 0 if $mode & 022;
1284 } ## end sub is_safe_file
1286 # If the rcfile (whichever one we decided was the right one to read)
1287 # exists, we safely do it.
1289 safe_do("./$rcfile");
1292 # If there isn't one here, try the user's home directory.
1293 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1294 safe_do("$ENV{HOME}/$rcfile");
1297 # Else try the login directory.
1298 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1299 safe_do("$ENV{LOGDIR}/$rcfile");
1302 # If the PERLDB_OPTS variable has options in it, parse those out next.
1303 if ( defined $ENV{PERLDB_OPTS} ) {
1304 parse_options( $ENV{PERLDB_OPTS} );
1309 The last thing we do during initialization is determine which subroutine is
1310 to be used to obtain a new terminal when a new debugger is started. Right now,
1311 the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
1316 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1317 # Works if you're running an xterm or xterm-like window, or you're on
1318 # OS/2, or on Mac OS X. This may need some expansion.
1320 if (not defined &get_fork_TTY) # only if no routine exists
1322 if ( defined $remoteport ) {
1323 # Expect an inetd-like server
1324 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1326 elsif (defined $ENV{TERM} # If we know what kind
1327 # of terminal this is,
1328 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1329 and defined $ENV{DISPLAY} # and what display it's on,
1332 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1334 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1335 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1337 elsif ( $^O eq 'darwin' # If this is Mac OS X
1338 and defined $ENV{TERM_PROGRAM} # and we're running inside
1339 and $ENV{TERM_PROGRAM}
1340 eq 'Apple_Terminal' # Terminal.app
1343 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1345 } ## end if (not defined &get_fork_TTY...
1347 # untaint $^O, which may have been tainted by the last statement.
1348 # see bug [perl #24674]
1352 # Here begin the unreadable code. It needs fixing.
1354 =head2 RESTART PROCESSING
1356 This section handles the restart command. When the C<R> command is invoked, it
1357 tries to capture all of the state it can into environment variables, and
1358 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1359 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1360 the R command stuffed into the environment variables.
1362 PERLDB_RESTART - flag only, contains no restart data itself.
1363 PERLDB_HIST - command history, if it's available
1364 PERLDB_ON_LOAD - breakpoints set by the rc file
1365 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1366 PERLDB_VISITED - files that had breakpoints
1367 PERLDB_FILE_... - breakpoints for a file
1368 PERLDB_OPT - active options
1369 PERLDB_INC - the original @INC
1370 PERLDB_PRETYPE - preprompt debugger actions
1371 PERLDB_PRE - preprompt Perl code
1372 PERLDB_POST - post-prompt Perl code
1373 PERLDB_TYPEAHEAD - typeahead captured by readline()
1375 We chug through all these variables and plug the values saved in them
1376 back into the appropriate spots in the debugger.
1380 use vars qw(%postponed_file @typeahead);
1382 our (@hist, @truehist);
1384 sub _restore_shared_globals_after_restart
1386 @hist = get_list('PERLDB_HIST');
1387 %break_on_load = get_list("PERLDB_ON_LOAD");
1388 %postponed = get_list("PERLDB_POSTPONE");
1392 share(%break_on_load);
1396 sub _restore_breakpoints_and_actions {
1398 my @had_breakpoints = get_list("PERLDB_VISITED");
1400 for my $file_idx ( 0 .. $#had_breakpoints ) {
1401 my $filename = $had_breakpoints[$file_idx];
1402 my %pf = get_list("PERLDB_FILE_$file_idx");
1403 $postponed_file{ $filename } = \%pf if %pf;
1404 my @lines = sort {$a <=> $b} keys(%pf);
1405 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1406 for my $line_idx (0 .. $#lines) {
1407 _set_breakpoint_enabled_status(
1410 ($enabled_statuses[$line_idx] ? 1 : ''),
1418 sub _restore_options_after_restart
1420 my %options_map = get_list("PERLDB_OPT");
1422 while ( my ( $opt, $val ) = each %options_map ) {
1423 $val =~ s/[\\\']/\\$1/g;
1424 parse_options("$opt'$val'");
1430 sub _restore_globals_after_restart
1432 # restore original @INC
1433 @INC = get_list("PERLDB_INC");
1436 # return pre/postprompt actions and typeahead buffer
1437 $pretype = [ get_list("PERLDB_PRETYPE") ];
1438 $pre = [ get_list("PERLDB_PRE") ];
1439 $post = [ get_list("PERLDB_POST") ];
1440 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1446 if ( exists $ENV{PERLDB_RESTART} ) {
1448 # We're restarting, so we don't need the flag that says to restart anymore.
1449 delete $ENV{PERLDB_RESTART};
1452 _restore_shared_globals_after_restart();
1454 _restore_breakpoints_and_actions();
1457 _restore_options_after_restart();
1459 _restore_globals_after_restart();
1460 } ## end if (exists $ENV{PERLDB_RESTART...
1462 =head2 SETTING UP THE TERMINAL
1464 Now, we'll decide how the debugger is going to interact with the user.
1465 If there's no TTY, we set the debugger to run non-stop; there's not going
1466 to be anyone there to enter commands.
1470 use vars qw($notty $console $tty $LINEINFO);
1471 use vars qw($lineinfo $doccmd);
1482 If there is a TTY, we have to determine who it belongs to before we can
1483 proceed. If this is a slave editor or graphical debugger (denoted by
1484 the first command-line switch being '-emacs'), we shift this off and
1485 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1491 # Is Perl being run from a slave editor or graphical debugger?
1492 # If so, don't use readline, and set $slave_editor = 1.
1493 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1498 #require Term::ReadLine;
1502 We then determine what the console should be on various systems:
1506 =item * Cygwin - We use C<stdin> instead of a separate device.
1510 if ( $^O eq 'cygwin' ) {
1512 # /dev/tty is binary. use stdin for textmode
1516 =item * Unix - use C</dev/tty>.
1520 elsif ( -e "/dev/tty" ) {
1521 $console = "/dev/tty";
1524 =item * Windows or MSDOS - use C<con>.
1528 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1532 =item * VMS - use C<sys$command>.
1538 # everything else is ...
1539 $console = "sys\$command";
1546 Several other systems don't use a specific console. We C<undef $console>
1547 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1548 with a slave editor).
1552 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1554 # /dev/tty is binary. use stdin for textmode
1558 if ( $^O eq 'NetWare' ) {
1560 # /dev/tty is binary. use stdin for textmode
1564 # In OS/2, we need to use STDIN to get textmode too, even though
1565 # it pretty much looks like Unix otherwise.
1566 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1573 If there is a TTY hanging around from a parent, we use that as the console.
1577 $console = $tty if defined $tty;
1579 =head2 SOCKET HANDLING
1581 The debugger is capable of opening a socket and carrying out a debugging
1582 session over the socket.
1584 If C<RemotePort> was defined in the options, the debugger assumes that it
1585 should try to start a debugging session on that port. It builds the socket
1586 and then tries to connect the input and output filehandles to it.
1590 # Handle socket stuff.
1592 if ( defined $remoteport ) {
1594 # If RemotePort was defined in the options, connect input and output
1596 $IN = $OUT = connect_remoteport();
1597 } ## end if (defined $remoteport)
1601 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1602 this is probably a situation where multiple debuggers are running (for example,
1603 a backticked command that starts up another debugger). We create a new IN and
1604 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1612 # Two debuggers running (probably a system or a backtick that invokes
1613 # the debugger itself under the running one). create a new IN and OUT
1614 # filehandle, and do the necessary mojo to create a new tty if we
1615 # know how, and we can.
1616 create_IN_OUT(4) if $CreateTTY & 4;
1619 # If we have a console, check to see if there are separate ins and
1620 # outs to open. (They are assumed identical if not.)
1622 my ( $i, $o ) = split /,/, $console;
1623 $o = $i unless defined $o;
1625 # read/write on in, or just read, or read on STDIN.
1627 || open( IN, "<$i" )
1628 || open( IN, "<&STDIN" );
1630 # read/write/create/clobber out, or write/create/clobber out,
1631 # or merge with STDERR, or merge with STDOUT.
1633 || open( OUT, ">$o" )
1634 || open( OUT, ">&STDERR" )
1635 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1637 } ## end if ($console)
1638 elsif ( not defined $console ) {
1640 # No console. Open STDIN.
1641 open( IN, "<&STDIN" );
1643 # merge with STDERR, or with STDOUT.
1644 open( OUT, ">&STDERR" )
1645 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1646 $console = 'STDIN/OUT';
1647 } ## end elsif (not defined $console)
1649 # Keep copies of the filehandles so that when the pager runs, it
1650 # can close standard input without clobbering ours.
1651 if ($console or (not defined($console))) {
1655 } ## end elsif (from if(defined $remoteport))
1657 # Unbuffer DB::OUT. We need to see responses right away.
1660 # Line info goes to debugger output unless pointed elsewhere.
1661 # Pointing elsewhere makes it possible for slave editors to
1662 # keep track of file and position. We have both a filehandle
1663 # and a I/O description to keep track of.
1664 $LINEINFO = $OUT unless defined $LINEINFO;
1665 $lineinfo = $console unless defined $lineinfo;
1666 # share($LINEINFO); # <- unable to share globs
1671 To finish initialization, we show the debugger greeting,
1672 and then call the C<afterinit()> subroutine if there is one.
1676 # Show the debugger greeting.
1677 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1678 unless ($runnonstop) {
1681 if ( $term_pid eq '-1' ) {
1682 print $OUT "\nDaughter DB session started...\n";
1685 print $OUT "\nLoading DB routines from $header\n";
1688 $slave_editor ? "enabled" : "available", ".\n"
1691 "\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
1692 } ## end else [ if ($term_pid eq '-1')
1693 } ## end unless ($runnonstop)
1694 } ## end else [ if ($notty)
1696 # XXX This looks like a bug to me.
1697 # Why copy to @ARGS and then futz with @args?
1700 # Make sure backslashes before single quotes are stripped out, and
1701 # keep args unless they are numeric (XXX why?)
1702 # s/\'/\\\'/g; # removed while not justified understandably
1703 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1706 # If there was an afterinit() sub defined, call it. It will get
1707 # executed in our scope, so it can fiddle with debugger globals.
1708 if ( defined &afterinit ) { # May be defined in $rcfile
1712 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1713 use vars qw($I_m_init);
1717 ############################################################ Subroutines
1723 This gigantic subroutine is the heart of the debugger. Called before every
1724 statement, its job is to determine if a breakpoint has been reached, and
1725 stop if so; read commands from the user, parse them, and execute
1726 them, and then send execution off to the next statement.
1728 Note that the order in which the commands are processed is very important;
1729 some commands earlier in the loop will actually alter the C<$cmd> variable
1730 to create other commands to be executed later. This is all highly I<optimized>
1731 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1732 see what's happening in any given command.
1736 # $cmd cannot be an our() variable unfortunately (possible perl bug?).
1766 sub _DB__determine_if_we_should_break
1768 # if we have something here, see if we should break.
1769 # $stop is lexical and local to this block - $action on the other hand
1774 && _is_breakpoint_enabled($filename, $line)
1775 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1778 # Stop if the stop criterion says to just stop.
1779 if ( $stop eq '1' ) {
1783 # It's a conditional stop; eval it in the user's context and
1784 # see if we should stop. If so, remove the one-time sigil.
1786 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1788 # If the breakpoint is temporary, then delete its enabled status.
1789 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1790 _cancel_breakpoint_temp_enabled_status($filename, $line);
1793 } ## end if ($dbline{$line} && ...
1796 sub _DB__is_finished {
1797 if ($finished and $level <= 1) {
1806 sub _DB__read_next_cmd
1810 # We have a terminal, or can get one ...
1815 # ... and it belogs to this PID or we get one for this PID ...
1816 if ($term_pid != $$) {
1820 # ... and we got a line of command input ...
1821 $cmd = DB::readline(
1822 "$pidprompt $tid DB"
1825 . ( '>' x $level ) . " "
1828 return defined($cmd);
1831 sub _DB__trim_command_and_return_first_component {
1834 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1835 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1837 my ($verb, $args) = $cmd =~ m{\A(\S*)\s*(.*)}s;
1839 $obj->cmd_verb($verb);
1840 $obj->cmd_args($args);
1845 sub _DB__handle_f_command {
1848 if ($file = $obj->cmd_args) {
1849 # help for no arguments (old-style was return from sub).
1852 "The old f command is now the r command.\n"; # hint
1853 print $OUT "The new f command switches filenames.\n";
1855 } ## end if (!$file)
1857 # if not in magic file list, try a close match.
1858 if ( !defined $main::{ '_<' . $file } ) {
1859 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1861 $try = substr( $try, 2 );
1862 print $OUT "Choosing $try matching '$file':\n";
1865 } ## end if (($try) = grep(m#^_<.*$file#...
1866 } ## end if (!defined $main::{ ...
1868 # If not successfully switched now, we failed.
1869 if ( !defined $main::{ '_<' . $file } ) {
1870 print $OUT "No file matching '$file' is loaded.\n";
1874 # We switched, so switch the debugger internals around.
1875 elsif ( $file ne $filename ) {
1876 *dbline = $main::{ '_<' . $file };
1881 } ## end elsif ($file ne $filename)
1883 # We didn't switch; say we didn't.
1885 print $OUT "Already in $file.\n";
1893 sub _DB__handle_dot_command {
1897 if ($obj->_is_full('.')) {
1898 $incr = -1; # stay at current line
1900 # Reset everything to the old location.
1902 $filename = $filename_ini;
1903 *dbline = $main::{ '_<' . $filename };
1907 print_lineinfo($obj->position());
1914 sub _DB__handle_y_command {
1917 if (my ($match_level, $match_vars)
1918 = $obj->cmd_args =~ /\A(?:(\d*)\s*(.*))?\z/) {
1920 # See if we've got the necessary support.
1921 if (!eval { require PadWalker; PadWalker->VERSION(0.08) }) {
1925 ? "PadWalker module not found - please install\n"
1931 # Load up dumpvar if we don't have it. If we can, that is.
1932 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1933 defined &main::dumpvar
1934 or print $OUT "dumpvar.pl not available.\n"
1937 # Got all the modules we need. Find them and print them.
1938 my @vars = split( ' ', $match_vars || '' );
1941 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
1943 # Oops. Can't find it.
1950 # Show the desired vars with dumplex().
1951 my $savout = select($OUT);
1953 # Have dumplex dump the lexicals.
1954 foreach my $key (sort keys %$h) {
1955 dumpvar::dumplex( $key, $h->{$key},
1956 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
1964 sub _DB__handle_c_command {
1967 my $i = $obj->cmd_args;
1969 if ($i =~ m#\A[\w:]*\z#) {
1971 # Hey, show's over. The debugged program finished
1972 # executing already.
1973 next CMD if _DB__is_finished();
1975 # Capture the place to put a one-time break.
1978 # Probably not needed, since we finish an interactive
1979 # sub-session anyway...
1980 # local $filename = $filename;
1981 # local *dbline = *dbline; # XXX Would this work?!
1983 # The above question wonders if localizing the alias
1984 # to the magic array works or not. Since it's commented
1985 # out, we'll just leave that to speculation for now.
1987 # If the "subname" isn't all digits, we'll assume it
1988 # is a subroutine name, and try to find it.
1989 if ( $subname =~ /\D/ ) { # subroutine name
1990 # Qualify it to the current package unless it's
1991 # already qualified.
1992 $subname = $package . "::" . $subname
1993 unless $subname =~ /::/;
1995 # find_sub will return "file:line_number" corresponding
1996 # to where the subroutine is defined; we call find_sub,
1997 # break up the return value, and assign it in one
1999 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2001 # Force the line number to be numeric.
2004 # If we got a line number, we found the sub.
2007 # Switch all the debugger's internals around so
2008 # we're actually working with that file.
2010 *dbline = $main::{ '_<' . $filename };
2012 # Mark that there's a breakpoint in this file.
2013 $had_breakpoints{$filename} |= 1;
2015 # Scan forward to the first executable line
2016 # after the 'sub whatever' line.
2019 while ($dbline[$_line_num] == 0 && $_line_num< $max)
2026 # We didn't find a sub by that name.
2028 print $OUT "Subroutine $subname not found.\n";
2031 } ## end if ($subname =~ /\D/)
2033 # At this point, either the subname was all digits (an
2034 # absolute line-break request) or we've scanned through
2035 # the code following the definition of the sub, looking
2036 # for an executable, which we may or may not have found.
2038 # If $i (which we set $subname from) is non-zero, we
2039 # got a request to break at some line somewhere. On
2040 # one hand, if there wasn't any real subroutine name
2041 # involved, this will be a request to break in the current
2042 # file at the specified line, so we have to check to make
2043 # sure that the line specified really is breakable.
2045 # On the other hand, if there was a subname supplied, the
2046 # preceding block has moved us to the proper file and
2047 # location within that file, and then scanned forward
2048 # looking for the next executable line. We have to make
2049 # sure that one was found.
2051 # On the gripping hand, we can't do anything unless the
2052 # current value of $i points to a valid breakable line.
2057 if ( $dbline[$i] == 0 ) {
2058 print $OUT "Line $i not breakable.\n";
2062 # Yes. Set up the one-time-break sigil.
2063 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2064 _enable_breakpoint_temp_enabled_status($filename, $i);
2067 # Turn off stack tracing from here up.
2068 for my $j (0 .. $stack_depth) {
2077 sub _DB__handle_forward_slash_command {
2080 # The pattern as a string.
2081 use vars qw($inpat);
2083 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2085 # Remove the final slash.
2086 $inpat =~ s:([^\\])/$:$1:;
2088 # If the pattern isn't null ...
2089 if ( $inpat ne "" ) {
2091 # Turn of warn and die procesing for a bit.
2092 local $SIG{__DIE__};
2093 local $SIG{__WARN__};
2095 # Create the pattern.
2096 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2099 # Oops. Bad pattern. No biscuit.
2100 # Print the eval error and go back for more
2106 } ## end if ($inpat ne "")
2108 # Set up to stop on wrap-around.
2111 # Don't move off the current line.
2114 my $pat = $obj->pat;
2116 # Done in eval so nothing breaks if the pattern
2117 # does something weird.
2122 # Move ahead one line.
2125 # Wrap if we pass the last line.
2126 $start = 1 if ($start > $max);
2128 # Stop if we have gotten back to this line again,
2129 last if ($start == $end);
2131 # A hit! (Note, though, that we are doing
2132 # case-insensitive matching. Maybe a qr//
2133 # expression would be better, so the user could
2134 # do case-sensitive matching if desired.
2135 if ($dbline[$start] =~ m/$pat/i) {
2136 if ($slave_editor) {
2137 # Handle proper escaping in the slave.
2138 print $OUT "\032\032$filename:$start:0\n";
2141 # Just print the line normally.
2142 print $OUT "$start:\t",$dbline[$start],"\n";
2144 # And quit since we found something.
2154 # If we wrapped, there never was a match.
2155 if ( $start == $end ) {
2156 print {$OUT} "/$pat/: not found\n";
2164 sub _DB__handle_question_mark_command {
2167 # ? - backward pattern search.
2168 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2170 # Get the pattern, remove trailing question mark.
2171 $inpat =~ s:([^\\])\?$:$1:;
2173 # If we've got one ...
2174 if ( $inpat ne "" ) {
2176 # Turn off die & warn handlers.
2177 local $SIG{__DIE__};
2178 local $SIG{__WARN__};
2179 eval '$inpat =~ m' . "\a$inpat\a";
2183 # Ouch. Not good. Print the error.
2188 } ## end if ($inpat ne "")
2190 # Where we are now is where to stop after wraparound.
2193 # Don't move away from this line.
2196 my $pat = $obj->pat;
2197 # Search inside the eval to prevent pattern badness
2205 # Wrap if we pass the first line.
2207 $start = $max if ($start <= 0);
2209 # Quit if we get back where we started,
2210 last if ($start == $end);
2213 if ($dbline[$start] =~ m/$pat/i) {
2214 if ($slave_editor) {
2215 # Yep, follow slave editor requirements.
2216 print $OUT "\032\032$filename:$start:0\n";
2219 # Yep, just print normally.
2220 print $OUT "$start:\t",$dbline[$start],"\n";
2229 # Say we failed if the loop never found anything,
2230 if ( $start == $end ) {
2231 print {$OUT} "?$pat?: not found\n";
2239 sub _DB__handle_restart_and_rerun_commands {
2242 my $cmd_cmd = $obj->cmd_verb;
2243 my $cmd_params = $obj->cmd_args;
2244 # R - restart execution.
2245 # rerun - controlled restart execution.
2246 if ($cmd_cmd eq 'rerun' or $cmd_params eq '') {
2247 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
2249 # Close all non-system fds for a clean restart. A more
2250 # correct method would be to close all fds that were not
2251 # open when the process started, but this seems to be
2252 # hard. See "debugger 'R'estart and open database
2253 # connections" on p5p.
2255 my $max_fd = 1024; # default if POSIX can't be loaded
2256 if (eval { require POSIX }) {
2257 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
2260 if (defined $max_fd) {
2261 foreach ($^F+1 .. $max_fd-1) {
2262 next unless open FD_TO_CLOSE, "<&=$_";
2267 # And run Perl again. We use exec() to keep the
2268 # PID stable (and that way $ini_pids is still valid).
2269 exec(@args) or print {$OUT} "exec failed: $!\n";
2277 sub _DB__handle_run_command_in_pager_command {
2280 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
2281 if ( $pager =~ /^\|/ ) {
2283 # Default pager is into a pipe. Redirect I/O.
2284 open( SAVEOUT, ">&STDOUT" )
2285 || _db_warn("Can't save STDOUT");
2286 open( STDOUT, ">&OUT" )
2287 || _db_warn("Can't redirect STDOUT");
2288 } ## end if ($pager =~ /^\|/)
2291 # Not into a pipe. STDOUT is safe.
2292 open( SAVEOUT, ">&OUT" ) || _db_warn("Can't save DB::OUT");
2295 # Fix up environment to record we have less if so.
2298 unless ( $obj->piped(scalar ( open( OUT, $pager ) ) ) ) {
2300 # Couldn't open pipe to pager.
2301 _db_warn("Can't pipe output to '$pager'");
2302 if ( $pager =~ /^\|/ ) {
2304 # Redirect I/O back again.
2305 open( OUT, ">&STDOUT" ) # XXX: lost message
2306 || _db_warn("Can't restore DB::OUT");
2307 open( STDOUT, ">&SAVEOUT" )
2308 || _db_warn("Can't restore STDOUT");
2310 } ## end if ($pager =~ /^\|/)
2313 # Redirect I/O. STDOUT already safe.
2314 open( OUT, ">&STDOUT" ) # XXX: lost message
2315 || _db_warn("Can't restore DB::OUT");
2318 } ## end unless ($piped = open(OUT,...
2320 # Set up broken-pipe handler if necessary.
2321 $SIG{PIPE} = \&DB::catch
2323 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
2326 # Save current filehandle, and put it back.
2327 $obj->selected(scalar( select(OUT) ));
2328 # Don't put it back if pager was a pipe.
2329 if ($cmd !~ /\A\|\|/)
2331 select($obj->selected());
2335 # Trim off the pipe symbols and run the command now.
2336 $cmd =~ s#\A\|+\s*##;
2343 sub _DB__handle_m_command {
2346 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2351 # m expr - set up DB::eval to do the work
2352 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2353 $onetimeDump = 'methods'; # method output gets used there
2359 sub _DB__at_end_of_every_command {
2362 # At the end of every command:
2365 # Unhook the pipe mechanism now.
2366 if ( $pager =~ /^\|/ ) {
2368 # No error from the child.
2371 # we cannot warn here: the handle is missing --tchrist
2372 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
2374 # most of the $? crud was coping with broken cshisms
2375 # $? is explicitly set to 0, so this never runs.
2377 print SAVEOUT "Pager '$pager' failed: ";
2379 print SAVEOUT "shell returned -1\n";
2382 print SAVEOUT ( $? & 127 )
2383 ? " (SIG#" . ( $? & 127 ) . ")"
2384 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
2387 print SAVEOUT "status ", ( $? >> 8 ), "\n";
2391 # Reopen filehandle for our output (if we can) and
2392 # restore STDOUT (if we can).
2393 open( OUT, ">&STDOUT" ) || _db_warn("Can't restore DB::OUT");
2394 open( STDOUT, ">&SAVEOUT" )
2395 || _db_warn("Can't restore STDOUT");
2397 # Turn off pipe exception handler if necessary.
2398 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
2400 # Will stop ignoring SIGPIPE if done like nohup(1)
2401 # does SIGINT but Perl doesn't give us a choice.
2402 } ## end if ($pager =~ /^\|/)
2405 # Non-piped "pager". Just restore STDOUT.
2406 open( OUT, ">&SAVEOUT" ) || _db_warn("Can't restore DB::OUT");
2409 # Close filehandle pager was using, restore the normal one
2413 if ($obj->selected() ne "") {
2414 select($obj->selected);
2420 } ## end if ($piped)
2427 # 'v' is the value (i.e: method name or subroutine ref).
2428 # 's' is subroutine.
2431 '-' => { t => 'm', v => '_handle_dash_command', },
2432 '.' => { t => 's', v => \&_DB__handle_dot_command, },
2433 '=' => { t => 'm', v => '_handle_equal_sign_command', },
2434 'H' => { t => 'm', v => '_handle_H_command', },
2435 'S' => { t => 'm', v => '_handle_S_command', },
2436 'T' => { t => 'm', v => '_handle_T_command', },
2437 'W' => { t => 'm', v => '_handle_W_command', },
2438 'c' => { t => 's', v => \&_DB__handle_c_command, },
2439 'f' => { t => 's', v => \&_DB__handle_f_command, },
2440 'm' => { t => 's', v => \&_DB__handle_m_command, },
2441 'n' => { t => 'm', v => '_handle_n_command', },
2442 'p' => { t => 'm', v => '_handle_p_command', },
2443 'q' => { t => 'm', v => '_handle_q_command', },
2444 'r' => { t => 'm', v => '_handle_r_command', },
2445 's' => { t => 'm', v => '_handle_s_command', },
2446 'save' => { t => 'm', v => '_handle_save_command', },
2447 'source' => { t => 'm', v => '_handle_source_command', },
2448 't' => { t => 'm', v => '_handle_t_command', },
2449 'w' => { t => 'm', v => '_handle_w_command', },
2450 'x' => { t => 'm', v => '_handle_x_command', },
2451 'y' => { t => 's', v => \&_DB__handle_y_command, },
2452 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, }
2454 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, }
2455 qw(enable disable)),
2457 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, },
2459 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, }
2460 qw(a A b B e E h i l L M o O P v w W)),
2465 # lock the debugger and get the thread id for the prompt
2469 my ($prefix, $after, $infix);
2475 if ($ENV{PERL5DB_THREADED}) {
2476 $tid = eval { "[".threads->tid."]" };
2482 my $obj = DB::Obj->new(
2484 position => \$position,
2487 explicit_stop => \$explicit_stop,
2489 cmd_args => \$cmd_args,
2490 cmd_verb => \$cmd_verb,
2493 selected => \$selected,
2497 $obj->_DB_on_init__initialize_globals(@_);
2499 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2500 # The code being debugged may have altered them.
2503 # Since DB::DB gets called after every line, we can use caller() to
2504 # figure out where we last were executing. Sneaky, eh? This works because
2505 # caller is returning all the extra information when called from the
2507 local ( $package, $filename, $line ) = caller;
2508 $filename_ini = $filename;
2510 # set up the context for DB::eval, so it can properly execute
2511 # code on behalf of the user. We add the package in so that the
2512 # code is eval'ed in the proper package (not in the debugger!).
2513 local $usercontext = _calc_usercontext($package);
2515 # Create an alias to the active file magical array to simplify
2517 local (*dbline) = $main::{ '_<' . $filename };
2519 # Last line in the program.
2522 _DB__determine_if_we_should_break(@_);
2524 # Preserve the current stop-or-not, and see if any of the W
2525 # (watch expressions) has changed.
2526 my $was_signal = $signal;
2528 # If we have any watch expressions ...
2529 $obj->_DB__handle_watch_expressions(@_);
2531 =head2 C<watchfunction()>
2533 C<watchfunction()> is a function that can be defined by the user; it is a
2534 function which will be run on each entry to C<DB::DB>; it gets the
2535 current package, filename, and line as its parameters.
2537 The watchfunction can do anything it likes; it is executing in the
2538 debugger's context, so it has access to all of the debugger's internal
2539 data structures and functions.
2541 C<watchfunction()> can control the debugger's actions. Any of the following
2542 will cause the debugger to return control to the user's program after
2543 C<watchfunction()> executes:
2549 Returning a false value from the C<watchfunction()> itself.
2553 Altering C<$single> to a false value.
2557 Altering C<$signal> to a false value.
2561 Turning off the C<4> bit in C<$trace> (this also disables the
2562 check for C<watchfunction()>. This can be done with
2570 # If there's a user-defined DB::watchfunction, call it with the
2571 # current package, filename, and line. The function executes in
2573 if ( $trace & 4 ) { # User-installed watch
2575 if watchfunction( $package, $filename, $line )
2578 and not( $trace & ~4 );
2579 } ## end if ($trace & 4)
2581 # Pick up any alteration to $signal in the watchfunction, and
2582 # turn off the signal now.
2583 $was_signal = $signal;
2586 =head2 GETTING READY TO EXECUTE COMMANDS
2588 The debugger decides to take control if single-step mode is on, the
2589 C<t> command was entered, or the user generated a signal. If the program
2590 has fallen off the end, we set things up so that entering further commands
2591 won't cause trouble, and we say that the program is over.
2595 # Make sure that we always print if asked for explicitly regardless
2596 # of $trace_to_depth .
2597 $explicit_stop = ($single || $was_signal);
2599 # Check to see if we should grab control ($single true,
2600 # trace set appropriately, or we got a signal).
2601 if ( $explicit_stop || ( $trace & 1 ) ) {
2602 $obj->_DB__grab_control(@_);
2603 } ## end if ($single || ($trace...
2607 If there's an action to be executed for the line we stopped at, execute it.
2608 If there are any preprompt actions, execute those as well.
2612 # If there's an action, do it now.
2618 # Are we nested another level (e.g., did we evaluate a function
2619 # that had a breakpoint in it at the debugger prompt)?
2620 if ( $single || $was_signal ) {
2622 # Yes, go down a level.
2623 local $level = $level + 1;
2625 # Do any pre-prompt actions.
2626 foreach $evalarg (@$pre) {
2630 # Complain about too much recursion if we passed the limit.
2632 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2635 # The line we're currently on. Set $incr to -1 to stay here
2636 # until we get a command that tells us to advance.
2638 $incr = -1; # for backward motion.
2640 # Tack preprompt debugger actions ahead of any actual input.
2641 @typeahead = ( @$pretype, @typeahead );
2643 =head2 WHERE ARE WE?
2645 XXX Relocate this section?
2647 The debugger normally shows the line corresponding to the current line of
2648 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2649 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2651 C<$incr> controls by how many lines the I<current> line should move forward
2652 after a command is executed. If set to -1, this indicates that the I<current>
2653 line shouldn't change.
2655 C<$start> is the I<current> line. It is used for things like knowing where to
2656 move forwards or backwards from when doing an C<L> or C<-> command.
2658 C<$max> tells the debugger where the last line of the current file is. It's
2659 used to terminate loops most often.
2661 =head2 THE COMMAND LOOP
2663 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2670 The outer part of the loop, starting at the C<CMD> label. This loop
2671 reads a command and then executes it.
2675 The inner part of the loop, starting at the C<PIPE> label. This part
2676 is wholly contained inside the C<CMD> block and only executes a command.
2677 Used to handle commands running inside a pager.
2681 So why have two labels to restart the loop? Because sometimes, it's easier to
2682 have a command I<generate> another command and then re-execute the loop to do
2683 the new command. This is faster, but perhaps a bit more convoluted.
2687 # The big command dispatch loop. It keeps running until the
2688 # user yields up control again.
2690 # If we have a terminal for input, and we get something back
2691 # from readline(), keep on processing.
2694 while (_DB__read_next_cmd($tid))
2698 # ... try to execute the input as debugger commands.
2700 # Don't stop running.
2703 # No signal is active.
2706 # Handle continued commands (ending with \):
2707 if ($cmd =~ s/\\\z/\n/) {
2708 $cmd .= DB::readline(" cont: ");
2712 =head4 The null command
2714 A newline entered by itself means I<re-execute the last command>. We grab the
2715 command out of C<$laststep> (where it was recorded previously), and copy it
2716 back into C<$cmd> to be executed below. If there wasn't any previous command,
2717 we'll do nothing below (no command will match). If there was, we also save it
2718 in the command history and fall through to allow the command parsing to pick
2723 # Empty input means repeat the last command.
2727 chomp($cmd); # get rid of the annoying extra newline
2728 if (length($cmd) >= 2) {
2729 push( @hist, $cmd );
2731 push( @truehist, $cmd );
2735 # This is a restart point for commands that didn't arrive
2736 # via direct user input. It allows us to 'redo PIPE' to
2737 # re-execute command processing without reading a new command.
2739 _DB__trim_command_and_return_first_component($obj);
2741 =head3 COMMAND ALIASES
2743 The debugger can create aliases for commands (these are stored in the
2744 C<%alias> hash). Before a command is executed, the command loop looks it up
2745 in the alias hash and substitutes the contents of the alias for the command,
2746 completely replacing it.
2750 # See if there's an alias for the command, and set it up if so.
2751 if ( $alias{$cmd_verb} ) {
2753 # Squelch signal handling; we want to keep control here
2754 # if something goes loco during the alias eval.
2755 local $SIG{__DIE__};
2756 local $SIG{__WARN__};
2758 # This is a command, so we eval it in the DEBUGGER's
2759 # scope! Otherwise, we can't see the special debugger
2760 # variables, or get to the debugger's subs. (Well, we
2761 # _could_, but why make it even more complicated?)
2762 eval "\$cmd =~ $alias{$cmd_verb}";
2765 print $OUT "Couldn't evaluate '$cmd_verb' alias: $@";
2768 _DB__trim_command_and_return_first_component($obj);
2769 } ## end if ($alias{$cmd_verb})
2771 =head3 MAIN-LINE COMMANDS
2773 All of these commands work up to and after the program being debugged has
2778 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2779 try to execute further, cleaning any restart-related stuff out of the
2780 environment, and executing with the last value of C<$?>.
2784 # All of these commands were remapped in perl 5.8.0;
2785 # we send them off to the secondary dispatcher (see below).
2786 $obj->_handle_special_char_cmd_wrapper_commands;
2787 _DB__trim_command_and_return_first_component($obj);
2789 if (my $cmd_rec = $cmd_lookup{$cmd_verb}) {
2790 my $type = $cmd_rec->{t};
2791 my $val = $cmd_rec->{v};
2795 elsif ($type eq 's') {
2800 =head4 C<t> - trace [n]
2802 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2803 If level is specified, set C<$trace_to_depth>.
2805 =head4 C<S> - list subroutines matching/not matching a pattern
2807 Walks through C<%sub>, checking to see whether or not to print the name.
2809 =head4 C<X> - list variables in current package
2811 Since the C<V> command actually processes this, just change this to the
2812 appropriate C<V> command and fall through.
2814 =head4 C<V> - list variables
2816 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2818 =head4 C<x> - evaluate and print an expression
2820 Hands the expression off to C<DB::eval>, setting it up to print the value
2821 via C<dumpvar.pl> instead of just printing it directly.
2823 =head4 C<m> - print methods
2825 Just uses C<DB::methods> to determine what methods are available.
2827 =head4 C<f> - switch files
2829 Switch to a different filename.
2831 =head4 C<.> - return to last-executed line.
2833 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2834 and then we look up the line in the magical C<%dbline> hash.
2836 =head4 C<-> - back one window
2838 We change C<$start> to be one window back; if we go back past the first line,
2839 we set it to be the first line. We ser C<$incr> to put us back at the
2840 currently-executing line, and then put a C<l $start +> (list one window from
2841 C<$start>) in C<$cmd> to be executed later.
2843 =head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
2845 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2846 problems, most notably that the default case of several commands destroying
2847 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2848 retain the old commands for those who were used to using them or who preferred
2849 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2850 deal with them instead of processing them in-line.
2852 =head4 C<y> - List lexicals in higher scope
2854 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2855 above the current one and then displays then using C<dumpvar.pl>.
2857 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2859 All of the commands below this point don't work after the program being
2860 debugged has ended. All of them check to see if the program has ended; this
2861 allows the commands to be relocated without worrying about a 'line of
2862 demarcation' above which commands can be entered anytime, and below which
2865 =head4 C<n> - single step, but don't trace down into subs
2867 Done by setting C<$single> to 2, which forces subs to execute straight through
2868 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2869 so a null command knows what to re-execute.
2871 =head4 C<s> - single-step, entering subs
2873 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2874 subs. Also saves C<s> as C<$lastcmd>.
2876 =head4 C<c> - run continuously, setting an optional breakpoint
2878 Most of the code for this command is taken up with locating the optional
2879 breakpoint, which is either a subroutine name or a line number. We set
2880 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2881 in this and all call levels above this one.
2883 =head4 C<r> - return from a subroutine
2885 For C<r> to work properly, the debugger has to stop execution again
2886 immediately after the return is executed. This is done by forcing
2887 single-stepping to be on in the call level above the current one. If
2888 we are printing return values when a C<r> is executed, set C<$doret>
2889 appropriately, and force us out of the command loop.
2891 =head4 C<T> - stack trace
2893 Just calls C<DB::print_trace>.
2895 =head4 C<w> - List window around current line.
2897 Just calls C<DB::cmd_w>.
2899 =head4 C<W> - watch-expression processing.
2901 Just calls C<DB::cmd_W>.
2903 =head4 C</> - search forward for a string in the source
2905 We take the argument and treat it as a pattern. If it turns out to be a
2906 bad one, we return the error we got from trying to C<eval> it and exit.
2907 If not, we create some code to do the search and C<eval> it so it can't
2912 _DB__handle_forward_slash_command($obj);
2914 =head4 C<?> - search backward for a string in the source
2916 Same as for C</>, except the loop runs backwards.
2920 _DB__handle_question_mark_command($obj);
2922 =head4 C<$rc> - Recall command
2924 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2925 that the terminal supports history). It find the the command required, puts it
2926 into C<$cmd>, and redoes the loop to execute it.
2930 # $rc - recall command.
2931 $obj->_handle_rc_recall_command;
2933 =head4 C<$sh$sh> - C<system()> command
2935 Calls the C<_db_system()> to handle the command. This keeps the C<STDIN> and
2936 C<STDOUT> from getting messed up.
2940 $obj->_handle_sh_command;
2942 =head4 C<$rc I<pattern> $rc> - Search command history
2944 Another command to manipulate C<@hist>: this one searches it with a pattern.
2945 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
2949 $obj->_handle_rc_search_history_command;
2951 =head4 C<$sh> - Invoke a shell
2953 Uses C<_db_system()> to invoke a shell.
2957 =head4 C<$sh I<command>> - Force execution of a command in a shell
2959 Like the above, but the command is passed to the shell. Again, we use
2960 C<_db_system()> to avoid problems with C<STDIN> and C<STDOUT>.
2962 =head4 C<H> - display commands in history
2964 Prints the contents of C<@hist> (if any).
2966 =head4 C<man, doc, perldoc> - look up documentation
2968 Just calls C<runman()> to print the appropriate document.
2972 $obj->_handle_doc_command;
2976 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
2977 the bottom of the loop.
2979 =head4 C<=> - define command alias
2981 Manipulates C<%alias> to add or list command aliases.
2983 =head4 C<source> - read commands from a file.
2985 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
2988 =head4 C<enable> C<disable> - enable or disable breakpoints
2990 This enables or disables breakpoints.
2992 =head4 C<save> - send current history to a file
2994 Takes the complete history, (not the shrunken version you see with C<H>),
2995 and saves it to the given filename, so it can be replayed using C<source>.
2997 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
2999 =head4 C<R> - restart
3001 Restart the debugger session.
3003 =head4 C<rerun> - rerun the current session
3005 Return to any given position in the B<true>-history list
3007 =head4 C<|, ||> - pipe output through the pager.
3009 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3010 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3011 pipe to the pager (restoring the output filehandles if this fails). If this
3012 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3013 set C<$signal>, sending us back into the debugger.
3015 We then trim off the pipe symbols and C<redo> the command loop at the
3016 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3021 # || - run command in the pager, with output to DB::OUT.
3022 _DB__handle_run_command_in_pager_command($obj);
3024 =head3 END OF COMMAND PARSING
3026 Anything left in C<$cmd> at this point is a Perl expression that we want to
3027 evaluate. We'll always evaluate in the user's context, and fully qualify
3028 any variables we might want to address in the C<DB> package.
3034 # Make sure the flag that says "the debugger's running" is
3035 # still on, to make sure we get control again.
3036 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3038 # Run *our* eval that executes in the caller's context.
3041 # Turn off the one-time-dump stuff now.
3043 $onetimeDump = undef;
3044 $onetimedumpDepth = undef;
3046 elsif ( $term_pid == $$ ) {
3047 eval { # May run under miniperl, when not available...
3052 # XXX If this is the master pid, print a newline.
3055 } ## end while (($term || &setterm...
3057 =head3 POST-COMMAND PROCESSING
3059 After each command, we check to see if the command output was piped anywhere.
3060 If so, we go through the necessary code to unhook the pipe and go back to
3061 our standard filehandles for input and output.
3066 _DB__at_end_of_every_command($obj);
3069 =head3 COMMAND LOOP TERMINATION
3071 When commands have finished executing, we come here. If the user closed the
3072 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3073 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3074 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3075 The interpreter will then execute the next line and then return control to us
3080 # No more commands? Quit.
3081 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
3083 # Evaluate post-prompt commands.
3084 foreach $evalarg (@$post) {
3087 } # if ($single || $signal)
3089 # Put the user's globals back where you found them.
3090 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3099 my $self = bless {}, $class;
3107 my ($self, $args) = @_;
3109 %{$self} = (%$self, %$args);
3116 foreach my $slot_name (qw(
3117 after explicit_stop infix pat piped position prefix selected cmd_verb
3120 my $slot = $slot_name;
3125 ${ $self->{$slot} } = shift;
3128 return ${ $self->{$slot} };
3131 *{"append_to_$slot"} = sub {
3135 return $self->$slot($self->$slot . $s);
3140 sub _DB_on_init__initialize_globals
3144 # Check for whether we should be running continuously or not.
3145 # _After_ the perl program is compiled, $single is set to 1:
3146 if ( $single and not $second_time++ ) {
3148 # Options say run non-stop. Run until we get an interrupt.
3149 if ($runnonstop) { # Disable until signal
3150 # If there's any call stack in place, turn off single
3151 # stepping into subs throughout the stack.
3152 for my $i (0 .. $stack_depth) {
3156 # And we are now no longer in single-step mode.
3159 # If we simply returned at this point, we wouldn't get
3160 # the trace info. Fall on through.
3162 } ## end if ($runnonstop)
3164 elsif ($ImmediateStop) {
3166 # We are supposed to stop here; XXX probably a break.
3167 $ImmediateStop = 0; # We've processed it; turn it off
3168 $signal = 1; # Simulate an interrupt to force
3169 # us into the command loop
3171 } ## end if ($single and not $second_time...
3173 # If we're in single-step mode, or an interrupt (real or fake)
3174 # has occurred, turn off non-stop mode.
3175 $runnonstop = 0 if $single or $signal;
3180 sub _DB__handle_watch_expressions
3185 for my $n (0 .. $#to_watch) {
3186 $evalarg = $to_watch[$n];
3187 local $onetimeDump; # Tell DB::eval() to not output results
3189 # Fix context DB::eval() wants to return an array, but
3190 # we need a scalar here.
3191 my ($val) = join( "', '", DB::eval() );
3192 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
3195 if ( $val ne $old_watch[$n] ) {
3197 # Yep! Show the difference, and fake an interrupt.
3200 Watchpoint $n:\t$to_watch[$n] changed:
3201 old value:\t$old_watch[$n]
3204 $old_watch[$n] = $val;
3205 } ## end if ($val ne $old_watch...
3206 } ## end for my $n (0 ..
3207 } ## end if ($trace & 2)
3212 sub _my_print_lineinfo
3214 my ($self, $i, $incr_pos) = @_;
3217 # Print it indented if tracing is on.
3218 DB::print_lineinfo( ' ' x $stack_depth,
3219 "$i:\t$DB::dbline[$i]" . $self->after );
3222 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3227 return $DB::dbline[$line];
3231 my ($self, $letter) = @_;
3233 return ($DB::cmd eq $letter);
3236 sub _DB__grab_control
3240 # Yes, grab control.
3241 if ($slave_editor) {
3243 # Tell the editor to update its position.
3244 $self->position("\032\032${DB::filename}:$line:0\n");
3245 DB::print_lineinfo($self->position());
3250 Special check: if we're in package C<DB::fake>, we've gone through the
3251 C<END> block at least once. We set up everything so that we can continue
3252 to enter commands and have a valid context to be in.
3256 elsif ( $DB::package eq 'DB::fake' ) {
3258 # Fallen off the end already.
3263 DB::print_help(<<EOP);
3264 Debugged program terminated. Use B<q> to quit or B<R> to restart,
3265 use B<o> I<inhibit_exit> to avoid stopping after program termination,
3266 B<h q>, B<h R> or B<h o> to get additional info.
3269 # Set the DB::eval context appropriately.
3270 $DB::package = 'main';
3271 $DB::usercontext = DB::_calc_usercontext($DB::package);
3272 } ## end elsif ($package eq 'DB::fake')
3276 If the program hasn't finished executing, we scan forward to the
3277 next executable line, print that out, build the prompt from the file and line
3278 number information, and print that.
3285 # Still somewhere in the midst of execution. Set up the
3287 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3288 # Perl 5 ones (sorry, we don't print Klingon
3291 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
3292 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
3293 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
3295 # Break up the prompt if it's really long.
3296 if ( length($self->prefix()) > 30 ) {
3297 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
3299 $self->infix(":\t");
3302 $self->infix("):\t");
3304 $self->prefix . $line. $self->infix
3305 . $self->_curr_line . $self->after
3309 # Print current line info, indenting if necessary.
3310 $self->_my_print_lineinfo($line, $self->position);
3313 my $line_i = sub { return $DB::dbline[$i]; };
3315 # Scan forward, stopping at either the end or the next
3317 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
3320 # Drop out on null statements, block closers, and comments.
3321 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
3323 # Drop out if the user interrupted us.
3326 # Append a newline if the line doesn't have one. Can happen
3327 # in eval'ed text, for instance.
3328 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
3330 # Next executable line.
3331 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
3333 $self->append_to_position($incr_pos);
3334 $self->_my_print_lineinfo($i, $incr_pos);
3335 } ## end for ($i = $line + 1 ; $i...
3336 } ## end else [ if ($slave_editor)
3341 sub _handle_t_command {
3344 my $levels = $self->cmd_args();
3346 if ((!length($levels)) or ($levels !~ /\D/)) {
3349 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3350 print {$OUT} "Trace = "
3352 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3361 sub _handle_S_command {
3364 if (my ($print_all_subs, $should_reverse, $Spatt)
3365 = $self->cmd_args =~ /\A((!)?(.+))?\z/) {
3366 # $Spatt is the pattern (if any) to use.
3368 my $Srev = defined $should_reverse;
3369 # No args - print all subs.
3370 my $Snocheck = !defined $print_all_subs;
3372 # Need to make these sane here.
3376 # Search through the debugger's magical hash of subs.
3377 # If $nocheck is true, just print the sub name.
3378 # Otherwise, check it against the pattern. We then use
3379 # the XOR trick to reverse the condition as required.
3380 foreach $subname ( sort( keys %sub ) ) {
3381 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3382 print $OUT $subname, "\n";
3391 sub _handle_V_command_and_X_command {
3394 $DB::cmd =~ s/^X\b/V $DB::package/;
3396 # Bare V commands get the currently-being-debugged package
3398 if ($self->_is_full('V')) {
3399 $DB::cmd = "V $DB::package";
3402 # V - show variables in package.
3403 if (my ($new_packname, $new_vars_str) =
3404 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3406 # Save the currently selected filehandle and
3407 # force output to debugger's filehandle (dumpvar
3408 # just does "print" for output).
3409 my $savout = select($OUT);
3411 # Grab package name and variables to dump.
3412 $packname = $new_packname;
3413 my @vars = split( ' ', $new_vars_str );
3415 # If main::dumpvar isn't here, get it.
3416 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3417 if ( defined &main::dumpvar ) {
3419 # We got it. Turn off subroutine entry/exit messages
3420 # for the moment, along with return values.
3424 # must detect sigpipe failures - not catching
3425 # then will cause the debugger to die.
3429 defined $option{dumpDepth}
3430 ? $option{dumpDepth}
3431 : -1, # assume -1 unless specified
3436 # The die doesn't need to include the $@, because
3437 # it will automatically get propagated for us.
3439 die unless $@ =~ /dumpvar print failed/;
3441 } ## end if (defined &main::dumpvar)
3444 # Couldn't load dumpvar.
3445 print $OUT "dumpvar.pl not available.\n";
3448 # Restore the output filehandle, and go round again.
3456 sub _handle_dash_command {
3459 if ($self->_is_full('-')) {
3461 # back up by a window; go to 1 if back too far.
3462 $start -= $incr + $window + 1;
3463 $start = 1 if $start <= 0;
3464 $incr = $window - 1;
3466 # Generate and execute a "l +" command (handled below).
3467 $DB::cmd = 'l ' . ($start) . '+';
3473 sub _n_or_s_commands_generic {
3474 my ($self, $new_val) = @_;
3476 next CMD if DB::_DB__is_finished();
3478 # Single step, but don't enter subs.
3481 # Save for empty command (repeat last).
3482 $laststep = $DB::cmd;
3487 my ($self, $letter, $new_val) = @_;
3489 if ($self->_is_full($letter)) {
3490 $self->_n_or_s_commands_generic($new_val);
3493 $self->_n_or_s_and_arg_commands_generic($letter, $new_val);
3499 sub _handle_n_command {
3502 return $self->_n_or_s('n', 2);
3505 sub _handle_s_command {
3508 return $self->_n_or_s('s', 1);
3511 sub _handle_r_command {
3514 # r - return from the current subroutine.
3515 if ($self->_is_full('r')) {
3517 # Can't do anything if the program's over.
3518 next CMD if DB::_DB__is_finished();
3520 # Turn on stack trace.
3521 $stack[$stack_depth] |= 1;
3523 # Print return value unless the stack is empty.
3524 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3531 sub _handle_T_command {
3534 if ($self->_is_full('T')) {
3535 DB::print_trace( $OUT, 1 ); # skip DB
3542 sub _handle_w_command {
3545 DB::cmd_w( 'w', $self->cmd_args() );
3551 sub _handle_W_command {
3554 if (my $arg = $self->cmd_args) {
3555 DB::cmd_W( 'W', $arg );
3562 sub _handle_rc_recall_command {
3565 # $rc - recall command.
3566 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3568 # No arguments, take one thing off history.
3569 pop(@hist) if length($DB::cmd) > 1;
3571 # Relative (- found)?
3572 # Y - index back from most recent (by 1 if bare minus)
3573 # N - go to that particular command slot or the last
3574 # thing if nothing following.
3577 scalar($minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist ))
3580 # Pick out the command desired.
3581 $DB::cmd = $hist[$self->cmd_verb];
3583 # Print the command to be executed and restart the loop
3584 # with that command in the buffer.
3585 print {$OUT} $DB::cmd, "\n";
3592 sub _handle_rc_search_history_command {
3595 # $rc pattern $rc - find a command in the history.
3596 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) {
3598 # Create the pattern to use.
3602 # Toss off last entry if length is >1 (and it always is).
3603 pop(@hist) if length($DB::cmd) > 1;
3607 # Look backward through the history.
3609 for ( $i = $#hist ; $i ; --$i ) {
3610 # Stop if we find it.
3611 last SEARCH_HIST if $hist[$i] =~ /$pat/;
3617 print $OUT "No such command!\n\n";
3621 # Found it. Put it in the buffer, print it, and process it.
3622 $DB::cmd = $hist[$i];
3623 print $OUT $DB::cmd, "\n";
3630 sub _handle_H_command {
3633 if ($self->cmd_args =~ m#\A\*#) {
3634 @hist = @truehist = ();
3635 print $OUT "History cleansed\n";
3639 if (my ($num) = $self->cmd_args =~ /\A(?:-(\d+))?/) {
3641 # Anything other than negative numbers is ignored by
3642 # the (incorrect) pattern, so this test does nothing.
3643 $end = $num ? ( $#hist - $num ) : 0;
3645 # Set to the minimum if less than zero.
3646 $hist = 0 if $hist < 0;
3648 # Start at the end of the array.
3649 # Stay in while we're still above the ending value.
3650 # Tick back by one each time around the loop.
3653 for ( $i = $#hist ; $i > $end ; $i-- ) {
3655 # Print the command unless it has no arguments.
3656 print $OUT "$i: ", $hist[$i], "\n"
3657 unless $hist[$i] =~ /^.?$/;
3666 sub _handle_doc_command {
3669 # man, perldoc, doc - show manual pages.
3671 = $DB::cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
3679 sub _handle_p_command {
3682 my $print_cmd = 'print {$DB::OUT} ';
3683 # p - print (no args): print $_.
3684 if ($self->_is_full('p')) {
3685 $DB::cmd = $print_cmd . '$_';
3688 # p - print the given expression.
3689 $DB::cmd =~ s/\Ap\b/$print_cmd /;
3695 sub _handle_equal_sign_command {
3698 if ($DB::cmd =~ s/\A=\s*//) {
3700 if ( length $DB::cmd == 0 ) {
3702 # No args, get current aliases.
3703 @keys = sort keys %alias;
3705 elsif ( my ( $k, $v ) = ( $DB::cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3707 # Creating a new alias. $k is alias name, $v is
3710 # can't use $_ or kill //g state
3711 for my $x ( $k, $v ) {
3713 # Escape "alarm" characters.
3717 # Substitute key for value, using alarm chars
3718 # as separators (which is why we escaped them in
3720 $alias{$k} = "s\a$k\a$v\a";
3722 # Turn off standard warn and die behavior.
3723 local $SIG{__DIE__};
3724 local $SIG{__WARN__};
3727 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3729 # Nope. Bad alias. Say so and get out.
3730 print $OUT "Can't alias $k to $v: $@\n";
3735 # We'll only list the new one.
3737 } ## end elsif (my ($k, $v) = ($DB::cmd...
3739 # The argument is the alias to list.
3747 # Messy metaquoting: Trim the substitution code off.
3748 # We use control-G as the delimiter because it's not
3749 # likely to appear in the alias.
3750 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3753 print $OUT "$k\t= $1\n";
3755 elsif ( defined $alias{$k} ) {
3757 # Couldn't trim it off; just print the alias code.
3758 print $OUT "$k\t$alias{$k}\n";
3763 print "No alias for $k\n";
3765 } ## end for my $k (@keys)
3772 sub _handle_source_command {
3775 # source - read commands from a file (or pipe!) and execute.
3776 if (my $sourced_fn = $self->cmd_args) {
3777 if ( open my $fh, $sourced_fn ) {
3779 # Opened OK; stick it in the list of file handles.
3785 DB::_db_warn("Can't execute '$sourced_fn': $!\n");
3793 sub _handle_enable_disable_commands {
3796 my $which_cmd = $self->cmd_verb;
3797 my $position = $self->cmd_args;
3799 if ($position !~ /\s/) {
3800 my ($fn, $line_num);
3801 if ($position =~ m{\A\d+\z})
3803 $fn = $DB::filename;
3804 $line_num = $position;
3806 elsif (my ($new_fn, $new_line_num)
3807 = $position =~ m{\A(.*):(\d+)\z}) {
3808 ($fn, $line_num) = ($new_fn, $new_line_num);
3812 DB::_db_warn("Wrong spec for enable/disable argument.\n");
3816 if (DB::_has_breakpoint_data_ref($fn, $line_num)) {
3817 DB::_set_breakpoint_enabled_status($fn, $line_num,
3818 ($which_cmd eq 'enable' ? 1 : '')
3822 DB::_db_warn("No breakpoint set at ${fn}:${line_num}\n");
3832 sub _handle_save_command {
3835 if (my $new_fn = $self->cmd_args) {
3836 my $filename = $new_fn || '.perl5dbrc'; # default?
3837 if ( open my $fh, '>', $filename ) {
3839 # chomp to remove extraneous newlines from source'd files
3840 chomp( my @truelist =
3841 map { m/\A\s*(save|source)/ ? "#$_" : $_ }
3843 print {$fh} join( "\n", @truelist );
3844 print "commands saved in $filename\n";
3847 DB::_db_warn("Can't save debugger commands in '$new_fn': $!\n");
3855 sub _n_or_s_and_arg_commands_generic {
3856 my ($self, $letter, $new_val) = @_;
3858 # s - single-step. Remember the last command was 's'.
3859 if ($DB::cmd =~ s#\A\Q$letter\E\s#\$DB::single = $new_val;\n#) {
3860 $laststep = $letter;
3866 sub _handle_sh_command {
3869 # $sh$sh - run a shell command (if it's all ASCII).
3870 # Can't run shell commands with Unicode in the debugger, hmm.
3871 my $my_cmd = $DB::cmd;
3872 if ($my_cmd =~ m#\A$sh#gms) {
3874 if ($my_cmd =~ m#\G\z#cgms) {
3875 # Run the user's shell. If none defined, run Bourne.
3876 # We resume execution when the shell terminates.
3877 DB::_db_system( $ENV{SHELL} || "/bin/sh" );
3880 elsif ($my_cmd =~ m#\G$sh\s*(.*)#cgms) {
3885 elsif ($my_cmd =~ m#\G\s*(.*)#cgms) {
3886 DB::_db_system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3892 sub _handle_x_command {
3895 if ($DB::cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
3896 $onetimeDump = 'dump'; # main::dumpvar shows the output
3898 # handle special "x 3 blah" syntax XXX propagate
3899 # doc back to special variables.
3900 if ( $DB::cmd =~ s#\A\s*(\d+)(?=\s)# #) {
3901 $onetimedumpDepth = $1;
3908 sub _handle_q_command {
3911 if ($self->_is_full('q')) {
3920 sub _handle_cmd_wrapper_commands {
3923 DB::cmd_wrapper( $self->cmd_verb, $self->cmd_args, $line );
3927 sub _handle_special_char_cmd_wrapper_commands {
3930 # All of these commands were remapped in perl 5.8.0;
3931 # we send them off to the secondary dispatcher (see below).
3932 if (my ($cmd_letter, $my_arg) = $DB::cmd =~ /\A([<>\{]{1,2})\s*(.*)/so) {
3933 DB::cmd_wrapper( $cmd_letter, $my_arg, $line );
3942 # The following code may be executed now:
3947 C<sub> is called whenever a subroutine call happens in the program being
3948 debugged. The variable C<$DB::sub> contains the name of the subroutine
3951 The core function of this subroutine is to actually call the sub in the proper
3952 context, capturing its output. This of course causes C<DB::DB> to get called
3953 again, repeating until the subroutine ends and returns control to C<DB::sub>
3954 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3955 return value, and returns its captured copy of the return value as its own
3956 return value. The value then feeds back into the program being debugged as if
3957 C<DB::sub> hadn't been there at all.
3959 C<sub> does all the work of printing the subroutine entry and exit messages
3960 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3961 and also prints the return value if needed (for the C<r> command and if
3962 the 16 bit is set in C<$frame>).
3964 It also tracks the subroutine call depth by saving the current setting of
3965 C<$single> in the C<@stack> package global; if this exceeds the value in
3966 C<$deep>, C<sub> automatically turns on printing of the current depth by
3967 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
3968 of stop/don't stop on entry to subs set as it currently is set.
3970 =head3 C<caller()> support
3972 If C<caller()> is called from the package C<DB>, it provides some
3973 additional data, in the following order:
3979 The package name the sub was in
3981 =item * C<$filename>
3983 The filename it was defined in
3987 The line number it was defined on
3989 =item * C<$subroutine>
3991 The subroutine name; C<(eval)> if an C<eval>().
3995 1 if it has arguments, 0 if not
3997 =item * C<$wantarray>
3999 1 if array context, 0 if scalar context
4001 =item * C<$evaltext>
4003 The C<eval>() text, if any (undefined for C<eval BLOCK>)
4005 =item * C<$is_require>
4007 frame was created by a C<use> or C<require> statement
4011 pragma information; subject to change between versions
4015 pragma information; subject to change between versions
4017 =item * C<@DB::args>
4019 arguments with which the subroutine was invoked
4027 # We need to fully qualify the name ("DB::sub") to make "use strict;"
4028 # happy. -- Shlomi Fish
4030 sub _indent_print_line_info {
4031 my ($offset, $str) = @_;
4033 print_lineinfo( ' ' x ($stack_depth - $offset), $str);
4038 sub _print_frame_message {
4042 if ($frame & 4) { # Extended frame entry message
4043 _indent_print_line_info(-1, "in ");
4045 # Why -1? But it works! :-(
4046 # Because print_trace will call add 1 to it and then call
4047 # dump_trace; this results in our skipping -1+1 = 0 stack frames
4050 # Now it's 0 because we extracted a function.
4051 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" );
4054 _indent_print_line_info(-1, "entering $sub$al\n" );
4062 # Do not use a regex in this subroutine -> results in corrupted memory
4063 # See: [perl #66110]
4065 # lock ourselves under threads
4068 # Whether or not the autoloader was running, a scalar to put the
4069 # sub's return value in (if needed), and an array to put the sub's
4070 # return value in (if needed).
4071 my ( $al, $ret, @ret ) = "";
4072 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
4073 print "creating new thread\n";
4076 # If the last ten characters are '::AUTOLOAD', note we've traced
4077 # into AUTOLOAD for $sub.
4078 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4080 $al = " for $$sub" if defined $$sub;
4083 # We stack the stack pointer and then increment it to protect us
4084 # from a situation that might unwind a whole bunch of call frames
4085 # at once. Localizing the stack pointer means that it will automatically
4086 # unwind the same amount when multiple stack frames are unwound.
4087 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4090 $#stack = $stack_depth;
4092 # Save current single-step setting.
4093 $stack[-1] = $single;
4095 # Turn off all flags except single-stepping.
4098 # If we've gotten really deeply recursed, turn on the flag that will
4099 # make us stop with the 'deep recursion' message.
4100 $single |= 4 if $stack_depth == $deep;
4102 # If frame messages are on ...
4104 _print_frame_message($al);
4105 # standard frame entry message
4107 my $print_exit_msg = sub {
4108 # Check for exit trace messages...
4111 if ($frame & 4) # Extended exit message
4113 _indent_print_line_info(0, "out ");
4114 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" );
4118 _indent_print_line_info(0, "exited $sub$al\n" );
4124 # Determine the sub's return type, and capture appropriately.
4127 # Called in array context. call sub and capture output.
4128 # DB::DB will recursively get control again if appropriate; we'll come
4129 # back here when the sub is finished.
4135 # Pop the single-step value back off the stack.
4136 $single |= $stack[ $stack_depth-- ];
4138 $print_exit_msg->();
4140 # Print the return info if we need to.
4141 if ( $doret eq $stack_depth or $frame & 16 ) {
4143 # Turn off output record separator.
4145 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4147 # Indent if we're printing because of $frame tracing.
4150 print {$fh} ' ' x $stack_depth;
4153 # Print the return value.
4154 print {$fh} "list context return from $sub:\n";
4155 dumpit( $fh, \@ret );
4157 # And don't print it again.
4159 } ## end if ($doret eq $stack_depth...
4160 # And we have to return the return value now.
4162 } ## end if (wantarray)
4166 if ( defined wantarray ) {
4168 # Save the value if it's wanted at all.
4173 # Void return, explicitly.
4178 # Pop the single-step value off the stack.
4179 $single |= $stack[ $stack_depth-- ];
4181 # If we're doing exit messages...
4182 $print_exit_msg->();
4184 # If we are supposed to show the return value... same as before.
4185 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
4187 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4188 print $fh ( ' ' x $stack_depth ) if $frame & 16;
4191 ? "scalar context return from $sub: "
4192 : "void context return from $sub\n"
4194 dumpit( $fh, $ret ) if defined wantarray;
4196 } ## end if ($doret eq $stack_depth...
4198 # Return the appropriate scalar value.
4200 } ## end else [ if (wantarray)
4207 # lock ourselves under threads
4210 # Whether or not the autoloader was running, a scalar to put the
4211 # sub's return value in (if needed), and an array to put the sub's
4212 # return value in (if needed).
4213 my ( $al, $ret, @ret ) = "";
4214 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
4215 print "creating new thread\n";
4218 # If the last ten characters are C'::AUTOLOAD', note we've traced
4219 # into AUTOLOAD for $sub.
4220 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4224 # We stack the stack pointer and then increment it to protect us
4225 # from a situation that might unwind a whole bunch of call frames
4226 # at once. Localizing the stack pointer means that it will automatically
4227 # unwind the same amount when multiple stack frames are unwound.
4228 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4231 $#stack = $stack_depth;
4233 # Save current single-step setting.
4234 $stack[-1] = $single;
4236 # Turn off all flags except single-stepping.
4239 # If we've gotten really deeply recursed, turn on the flag that will
4240 # make us stop with the 'deep recursion' message.
4241 $single |= 4 if $stack_depth == $deep;
4243 # If frame messages are on ...
4244 _print_frame_message($al);
4246 # Pop the single-step value back off the stack.
4247 $single |= $stack[ $stack_depth-- ];
4249 # call the original lvalue sub.
4253 # Abstracting common code from multiple places elsewhere:
4254 sub depth_print_lineinfo {
4255 my $always_print = shift;
4257 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth);
4260 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
4262 In Perl 5.8.0, there was a major realignment of the commands and what they did,
4263 Most of the changes were to systematize the command structure and to eliminate
4264 commands that threw away user input without checking.
4266 The following sections describe the code added to make it easy to support
4267 multiple command sets with conflicting command names. This section is a start
4268 at unifying all command processing to make it simpler to develop commands.
4270 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
4271 number, and C<$dbline> (the current line) as arguments.
4273 Support functions in this section which have multiple modes of failure C<die>
4274 on error; the rest simply return a false value.
4276 The user-interface functions (all of the C<cmd_*> functions) just output
4281 The C<%set> hash defines the mapping from command letter to subroutine
4284 C<%set> is a two-level hash, indexed by set name and then by command name.
4285 Note that trying to set the CommandSet to C<foobar> simply results in the
4286 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
4295 'A' => 'pre580_null',
4297 'B' => 'pre580_null',
4298 'd' => 'pre580_null',
4301 'M' => 'pre580_null',
4303 'o' => 'pre580_null',
4309 '<' => 'pre590_prepost',
4310 '<<' => 'pre590_prepost',
4311 '>' => 'pre590_prepost',
4312 '>>' => 'pre590_prepost',
4313 '{' => 'pre590_prepost',
4314 '{{' => 'pre590_prepost',
4318 my %breakpoints_data;
4320 sub _has_breakpoint_data_ref {
4321 my ($filename, $line) = @_;
4324 exists( $breakpoints_data{$filename} )
4326 exists( $breakpoints_data{$filename}{$line} )
4330 sub _get_breakpoint_data_ref {
4331 my ($filename, $line) = @_;
4333 return ($breakpoints_data{$filename}{$line} ||= +{});
4336 sub _delete_breakpoint_data_ref {
4337 my ($filename, $line) = @_;
4339 delete($breakpoints_data{$filename}{$line});
4340 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) {
4341 delete($breakpoints_data{$filename});
4347 sub _set_breakpoint_enabled_status {
4348 my ($filename, $line, $status) = @_;
4350 _get_breakpoint_data_ref($filename, $line)->{'enabled'} =
4357 sub _enable_breakpoint_temp_enabled_status {
4358 my ($filename, $line) = @_;
4360 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1;
4365 sub _cancel_breakpoint_temp_enabled_status {
4366 my ($filename, $line) = @_;
4368 my $ref = _get_breakpoint_data_ref($filename, $line);
4370 delete ($ref->{'temp_enabled'});
4373 _delete_breakpoint_data_ref($filename, $line);
4379 sub _is_breakpoint_enabled {
4380 my ($filename, $line) = @_;
4382 my $data_ref = _get_breakpoint_data_ref($filename, $line);
4383 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'});
4386 =head2 C<cmd_wrapper()> (API)
4388 C<cmd_wrapper()> allows the debugger to switch command sets
4389 depending on the value of the C<CommandSet> option.
4391 It tries to look up the command in the C<%set> package-level I<lexical>
4392 (which means external entities can't fiddle with it) and create the name of
4393 the sub to call based on the value found in the hash (if it's there). I<All>
4394 of the commands to be handled in a set have to be added to C<%set>; if they
4395 aren't found, the 5.8.0 equivalent is called (if there is one).
4397 This code uses symbolic references.
4404 my $dblineno = shift;
4406 # Assemble the command subroutine's name by looking up the
4407 # command set and command name in %set. If we can't find it,
4408 # default to the older version of the command.
4410 . ( $set{$CommandSet}{$cmd}
4411 || ( $cmd =~ /\A[<>{]+/o ? 'prepost' : $cmd ) );
4413 # Call the command subroutine, call it by name.
4414 return __PACKAGE__->can($call)->( $cmd, $line, $dblineno );
4415 } ## end sub cmd_wrapper
4417 =head3 C<cmd_a> (command)
4419 The C<a> command handles pre-execution actions. These are associated with a
4420 particular line, so they're stored in C<%dbline>. We default to the current
4421 line if none is specified.
4427 my $line = shift || ''; # [.|line] expr
4430 # If it's dot (here), or not all digits, use the current line.
4431 $line =~ s/\A\./$dbline/;
4433 # Should be a line number followed by an expression.
4434 if ( my ($lineno, $expr) = $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
4436 if (! length($lineno)) {
4440 # If we have an expression ...
4441 if ( length $expr ) {
4443 # ... but the line isn't breakable, complain.
4444 if ( $dbline[$lineno] == 0 ) {
4446 "Line $lineno($dbline[$lineno]) does not have an action?\n";
4450 # It's executable. Record that the line has an action.
4451 $had_breakpoints{$filename} |= 2;
4453 # Remove any action, temp breakpoint, etc.
4454 $dbline{$lineno} =~ s/\0[^\0]*//;
4456 # Add the action to the line.
4457 $dbline{$lineno} .= "\0" . action($expr);
4459 _set_breakpoint_enabled_status($filename, $lineno, 1);
4461 } ## end if (length $expr)
4462 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
4467 "Adding an action requires an optional lineno and an expression\n"
4472 =head3 C<cmd_A> (command)
4474 Delete actions. Similar to above, except the delete code is in a separate
4475 subroutine, C<delete_action>.
4481 my $line = shift || '';
4485 $line =~ s/^\./$dbline/;
4487 # Call delete_action with a null param to delete them all.
4488 # The '1' forces the eval to be true. It'll be false only
4489 # if delete_action blows up for some reason, in which case
4490 # we print $@ and get out.
4491 if ( $line eq '*' ) {
4492 if (! eval { _delete_all_actions(); 1 }) {
4498 # There's a real line number. Pass it to delete_action.
4499 # Error trapping is as above.
4500 elsif ( $line =~ /^(\S.*)/ ) {
4501 if (! eval { delete_action($1); 1 }) {
4507 # Swing and a miss. Bad syntax.
4510 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4514 =head3 C<delete_action> (API)
4516 C<delete_action> accepts either a line number or C<undef>. If a line number
4517 is specified, we check for the line being executable (if it's not, it
4518 couldn't have had an action). If it is, we just take the action off (this
4519 will get any kind of an action, including breakpoints).
4523 sub _remove_action_from_dbline {
4526 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4527 delete $dbline{$i} if $dbline{$i} eq '';
4532 sub _delete_all_actions {
4533 print {$OUT} "Deleting all actions...\n";
4535 for my $file ( keys %had_breakpoints ) {
4536 local *dbline = $main::{ '_<' . $file };
4539 for my $i (1 .. $max) {
4540 if ( defined $dbline{$i} ) {
4541 _remove_action_from_dbline($i);
4545 unless ( $had_breakpoints{$file} &= ~2 ) {
4546 delete $had_breakpoints{$file};
4556 if ( defined($i) ) {
4558 die "Line $i has no action .\n" if $dbline[$i] == 0;
4560 # Nuke whatever's there.
4561 _remove_action_from_dbline($i);
4564 _delete_all_actions();
4568 =head3 C<cmd_b> (command)
4570 Set breakpoints. Since breakpoints can be set in so many places, in so many
4571 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4572 we try to parse the command type, and then shuttle it off to an appropriate
4573 subroutine to actually do the work of setting the breakpoint in the right
4580 my $line = shift; # [.|line] [cond]
4583 my $default_cond = sub {
4585 return length($cond) ? $cond : '1';
4588 # Make . the current line number if it's there..
4589 $line =~ s/^\.(\s|\z)/$dbline$1/;
4591 # No line number, no condition. Simple break on current line.
4592 if ( $line =~ /^\s*$/ ) {
4593 cmd_b_line( $dbline, 1 );
4596 # Break on load for a file.
4597 elsif ( my ($file) = $line =~ /^load\b\s*(.*)/ ) {
4602 # b compile|postpone <some sub> [<condition>]
4603 # The interpreter actually traps this one for us; we just put the
4604 # necessary condition in the %postponed hash.
4605 elsif ( my ($action, $subname, $cond)
4606 = $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4608 # De-Perl4-ify the name - ' separators to ::.
4609 $subname =~ s/'/::/g;
4611 # Qualify it into the current package unless it's already qualified.
4612 $subname = "${package}::" . $subname unless $subname =~ /::/;
4614 # Add main if it starts with ::.
4615 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4617 # Save the break type for this sub.
4618 $postponed{$subname} = (($action eq 'postpone')
4619 ? ( "break +0 if " . $default_cond->($cond) )
4621 } ## end elsif ($line =~ ...
4622 # b <filename>:<line> [<condition>]
4623 elsif (my ($filename, $line_num, $cond)
4624 = $line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) {
4625 cmd_b_filename_line(
4628 (length($cond) ? $cond : '1'),
4631 # b <sub name> [<condition>]
4632 elsif ( my ($new_subname, $new_cond) =
4633 $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4636 $subname = $new_subname;
4637 cmd_b_sub( $subname, $default_cond->($new_cond) );
4640 # b <line> [<condition>].
4641 elsif ( my ($line_n, $cond) = $line =~ /^(\d*)\s*(.*)/ ) {
4643 # Capture the line. If none, it's the current line.
4644 $line = $line_n || $dbline;
4647 cmd_b_line( $line, $default_cond->($cond) );
4650 # Line didn't make sense.
4652 print "confused by line($line)?\n";
4658 =head3 C<break_on_load> (API)
4660 We want to break when this file is loaded. Mark this file in the
4661 C<%break_on_load> hash, and note that it has a breakpoint in
4662 C<%had_breakpoints>.
4668 $break_on_load{$file} = 1;
4669 $had_breakpoints{$file} |= 1;
4672 =head3 C<report_break_on_load> (API)
4674 Gives us an array of filenames that are set to break on load. Note that
4675 only files with break-on-load are in here, so simply showing the keys
4680 sub report_break_on_load {
4681 sort keys %break_on_load;
4684 =head3 C<cmd_b_load> (command)
4686 We take the file passed in and try to find it in C<%INC> (which maps modules
4687 to files they came from). We mark those files for break-on-load via
4688 C<break_on_load> and then report that it was done.
4696 # This is a block because that way we can use a redo inside it
4697 # even without there being any looping structure at all outside it.
4700 # Save short name and full path if found.
4702 push @files, $::INC{$file} if $::INC{$file};
4704 # Tack on .pm and do it again unless there was a '.' in the name
4706 $file .= '.pm', redo unless $file =~ /\./;
4709 # Do the real work here.
4710 break_on_load($_) for @files;
4712 # All the files that have break-on-load breakpoints.
4713 @files = report_break_on_load;
4715 # Normalize for the purposes of our printing this.
4718 print $OUT "Will stop on load of '@files'.\n";
4719 } ## end sub cmd_b_load
4721 =head3 C<$filename_error> (API package global)
4723 Several of the functions we need to implement in the API need to work both
4724 on the current file and on other files. We don't want to duplicate code, so
4725 C<$filename_error> is used to contain the name of the file that's being
4726 worked on (if it's not the current one).
4728 We can now build functions in pairs: the basic function works on the current
4729 file, and uses C<$filename_error> as part of its error message. Since this is
4730 initialized to C<"">, no filename will appear when we are working on the
4733 The second function is a wrapper which does the following:
4739 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4743 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4747 Calls the first function.
4749 The first function works on the I<current> file (i.e., the one we changed to),
4750 and prints C<$filename_error> in the error message (the name of the other file)
4751 if it needs to. When the functions return, C<*dbline> is restored to point
4752 to the actual current file (the one we're executing in) and
4753 C<$filename_error> is restored to C<"">. This restores everything to
4754 the way it was before the second function was called at all.
4756 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4763 use vars qw($filename_error);
4764 $filename_error = '';
4766 =head3 breakable_line(from, to) (API)
4768 The subroutine decides whether or not a line in the current file is breakable.
4769 It walks through C<@dbline> within the range of lines specified, looking for
4770 the first line that is breakable.
4772 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4773 first line I<after> C<$to> that's breakable, if there is one.
4775 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4776 first line I<before> C<$to> that's breakable, if there is one.
4780 sub breakable_line {
4782 my ( $from, $to ) = @_;
4784 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4787 # If there are at least 2 arguments, we're trying to search a range.
4790 # $delta is positive for a forward search, negative for a backward one.
4791 my $delta = $from < $to ? +1 : -1;
4793 # Keep us from running off the ends of the file.
4794 my $limit = $delta > 0 ? $#dbline : 1;
4796 # Clever test. If you're a mathematician, it's obvious why this
4797 # test works. If not:
4798 # If $delta is positive (going forward), $limit will be $#dbline.
4799 # If $to is less than $limit, ($limit - $to) will be positive, times
4800 # $delta of 1 (positive), so the result is > 0 and we should use $to
4801 # as the stopping point.
4803 # If $to is greater than $limit, ($limit - $to) is negative,
4804 # times $delta of 1 (positive), so the result is < 0 and we should
4805 # use $limit ($#dbline) as the stopping point.
4807 # If $delta is negative (going backward), $limit will be 1.
4808 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4809 # (negative) so the result is > 0, and we use $to as the stopping
4812 # If $to is less than zero, ($limit - $to) will be positive,
4813 # times $delta of -1 (negative), so the result is not > 0, and
4814 # we use $limit (1) as the stopping point.
4816 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4817 # (negative), still giving zero; the result is not > 0, and
4818 # we use $limit (1) as the stopping point.
4820 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4821 # (negative), giving a positive (>0) value, so we'll set $limit to
4824 $limit = $to if ( $limit - $to ) * $delta > 0;
4826 # The real search loop.
4827 # $i starts at $from (the point we want to start searching from).
4828 # We move through @dbline in the appropriate direction (determined
4829 # by $delta: either -1 (back) or +1 (ahead).
4830 # We stay in as long as we haven't hit an executable line
4831 # ($dbline[$i] == 0 means not executable) and we haven't reached
4832 # the limit yet (test similar to the above).
4833 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4835 } ## end if (@_ >= 2)
4837 # If $i points to a line that is executable, return that.
4838 return $i unless $dbline[$i] == 0;
4840 # Format the message and print it: no breakable lines in range.
4841 my ( $pl, $upto ) = ( '', '' );
4842 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4844 # If there's a filename in filename_error, we'll see it.
4846 die "Line$pl $from$upto$filename_error not breakable\n";
4847 } ## end sub breakable_line
4849 =head3 breakable_line_in_filename(file, from, to) (API)
4851 Like C<breakable_line>, but look in another file.
4855 sub breakable_line_in_filename {
4857 # Capture the file name.
4860 # Swap the magic line array over there temporarily.
4861 local *dbline = $main::{ '_<' . $f };
4863 # If there's an error, it's in this other file.
4864 local $filename_error = " of '$f'";
4866 # Find the breakable line.
4869 # *dbline and $filename_error get restored when this block ends.
4871 } ## end sub breakable_line_in_filename
4873 =head3 break_on_line(lineno, [condition]) (API)
4875 Adds a breakpoint with the specified condition (or 1 if no condition was
4876 specified) to the specified line. Dies if it can't.
4882 my $cond = @_ ? shift(@_) : 1;
4888 # Woops, not a breakable line. $filename_error allows us to say
4889 # if it was in a different file.
4890 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4892 # Mark this file as having breakpoints in it.
4893 $had_breakpoints{$filename} |= 1;
4895 # If there is an action or condition here already ...
4896 if ( $dbline{$i} ) {
4898 # ... swap this condition for the existing one.
4899 $dbline{$i} =~ s/^[^\0]*/$cond/;
4903 # Nothing here - just add the condition.
4904 $dbline{$i} = $cond;
4906 _set_breakpoint_enabled_status($filename, $i, 1);
4910 } ## end sub break_on_line
4912 =head3 cmd_b_line(line, [condition]) (command)
4914 Wrapper for C<break_on_line>. Prints the failure message if it
4920 if (not eval { break_on_line(@_); 1 }) {
4922 print $OUT $@ and return;
4926 } ## end sub cmd_b_line
4928 =head3 cmd_b_filename_line(line, [condition]) (command)
4930 Wrapper for C<break_on_filename_line>. Prints the failure message if it
4935 sub cmd_b_filename_line {
4936 if (not eval { break_on_filename_line(@_); 1 }) {
4938 print $OUT $@ and return;
4944 =head3 break_on_filename_line(file, line, [condition]) (API)
4946 Switches to the file specified and then calls C<break_on_line> to set
4951 sub break_on_filename_line {
4954 my $cond = @_ ? shift(@_) : 1;
4956 # Switch the magical hash temporarily.
4957 local *dbline = $main::{ '_<' . $f };
4959 # Localize the variables that break_on_line uses to make its message.
4960 local $filename_error = " of '$f'";
4961 local $filename = $f;
4963 # Add the breakpoint.
4964 break_on_line( $i, $cond );
4967 } ## end sub break_on_filename_line
4969 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4971 Switch to another file, search the range of lines specified for an
4972 executable one, and put a breakpoint on the first one you find.
4976 sub break_on_filename_line_range {
4980 my $cond = @_ ? shift(@_) : 1;
4982 # Find a breakable line if there is one.
4983 my $i = breakable_line_in_filename( $f, $from, $to );
4985 # Add the breakpoint.
4986 break_on_filename_line( $f, $i, $cond );
4989 } ## end sub break_on_filename_line_range
4991 =head3 subroutine_filename_lines(subname, [condition]) (API)
4993 Search for a subroutine within a given file. The condition is ignored.
4994 Uses C<find_sub> to locate the desired subroutine.
4998 sub subroutine_filename_lines {
4999 my ( $subname ) = @_;
5001 # Returned value from find_sub() is fullpathname:startline-endline.
5002 # The match creates the list (fullpathname, start, end).
5003 return (find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/);
5004 } ## end sub subroutine_filename_lines
5006 =head3 break_subroutine(subname) (API)
5008 Places a break on the first line possible in the specified subroutine. Uses
5009 C<subroutine_filename_lines> to find the subroutine, and
5010 C<break_on_filename_line_range> to place the break.
5014 sub break_subroutine {
5015 my $subname = shift;
5017 # Get filename, start, and end.
5018 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
5019 or die "Subroutine $subname not found.\n";
5022 # Null condition changes to '1' (always true).
5023 my $cond = @_ ? shift(@_) : 1;
5025 # Put a break the first place possible in the range of lines
5026 # that make up this subroutine.
5027 break_on_filename_line_range( $file, $s, $e, $cond );
5030 } ## end sub break_subroutine
5032 =head3 cmd_b_sub(subname, [condition]) (command)
5034 We take the incoming subroutine name and fully-qualify it as best we can.
5038 =item 1. If it's already fully-qualified, leave it alone.
5040 =item 2. Try putting it in the current package.
5042 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
5044 =item 4. If it starts with '::', put it in 'main::'.
5048 After all this cleanup, we call C<break_subroutine> to try to set the
5054 my $subname = shift;
5055 my $cond = @_ ? shift : 1;
5057 # If the subname isn't a code reference, qualify it so that
5058 # break_subroutine() will work right.
5059 if ( ref($subname) ne 'CODE' ) {
5062 $subname =~ s/'/::/g;
5065 # Put it in this package unless it's already qualified.
5066 if ($subname !~ /::/)
5068 $subname = $package . '::' . $subname;
5071 # Requalify it into CORE::GLOBAL if qualifying it into this
5072 # package resulted in its not being defined, but only do so
5073 # if it really is in CORE::GLOBAL.
5074 my $core_name = "CORE::GLOBAL::$s";
5075 if ((!defined(&$subname))
5077 and (defined &{$core_name}))
5079 $subname = $core_name;
5082 # Put it in package 'main' if it has a leading ::.
5083 if ($subname =~ /\A::/)
5085 $subname = "main" . $subname;
5087 } ## end if ( ref($subname) ne 'CODE' ) {
5089 # Try to set the breakpoint.
5090 if (not eval { break_subroutine( $subname, $cond ); 1 }) {
5097 } ## end sub cmd_b_sub
5099 =head3 C<cmd_B> - delete breakpoint(s) (command)
5101 The command mostly parses the command line and tries to turn the argument
5102 into a line spec. If it can't, it uses the current line. It then calls
5103 C<delete_breakpoint> to actually do the work.
5105 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
5106 thereby deleting all the breakpoints.
5113 # No line spec? Use dbline.
5114 # If there is one, use it if it's non-zero, or wipe it out if it is.
5115 my $line = ( $_[0] =~ /\A\./ ) ? $dbline : (shift || '');
5118 # If the line was dot, make the line the current one.
5119 $line =~ s/^\./$dbline/;
5121 # If it's * we're deleting all the breakpoints.
5122 if ( $line eq '*' ) {
5123 if (not eval { delete_breakpoint(); 1 }) {
5128 # If there is a line spec, delete the breakpoint on that line.
5129 elsif ( $line =~ /\A(\S.*)/ ) {
5130 if (not eval { delete_breakpoint( $line || $dbline ); 1 }) {
5134 } ## end elsif ($line =~ /^(\S.*)/)
5139 "Deleting a breakpoint requires a line number, or '*' for all\n"
5146 =head3 delete_breakpoint([line]) (API)
5148 This actually does the work of deleting either a single breakpoint, or all
5151 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
5152 just drop out with a message saying so. If it is, we remove the condition
5153 part of the 'condition\0action' that says there's a breakpoint here. If,
5154 after we've done that, there's nothing left, we delete the corresponding
5155 line in C<%dbline> to signal that no action needs to be taken for this line.
5157 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
5158 which lists all currently-loaded files which have breakpoints. We then look
5159 at each line in each of these files, temporarily switching the C<%dbline>
5160 and C<@dbline> structures to point to the files in question, and do what
5161 we did in the single line case: delete the condition in C<@dbline>, and
5162 delete the key in C<%dbline> if nothing's left.
5164 We then wholesale delete C<%postponed>, C<%postponed_file>, and
5165 C<%break_on_load>, because these structures contain breakpoints for files
5166 and code that haven't been loaded yet. We can just kill these off because there
5167 are no magical debugger structures associated with them.
5171 sub _remove_breakpoint_entry {
5175 _delete_breakpoint_data_ref($fn, $i);
5180 sub _delete_all_breakpoints {
5181 print {$OUT} "Deleting all breakpoints...\n";
5183 # %had_breakpoints lists every file that had at least one
5185 for my $fn ( keys %had_breakpoints ) {
5187 # Switch to the desired file temporarily.
5188 local *dbline = $main::{ '_<' . $fn };
5192 # For all lines in this file ...
5193 for my $i (1 .. $max) {
5195 # If there's a breakpoint or action on this line ...
5196 if ( defined $dbline{$i} ) {
5198 # ... remove the breakpoint.
5199 $dbline{$i} =~ s/\A[^\0]+//;
5200 if ( $dbline{$i} =~ s/\A\0?\z// ) {
5201 # Remove the entry altogether if no action is there.
5202 _remove_breakpoint_entry($fn, $i);
5204 } ## end if (defined $dbline{$i...
5205 } ## end for $i (1 .. $max)
5207 # If, after we turn off the "there were breakpoints in this file"
5208 # bit, the entry in %had_breakpoints for this file is zero,
5209 # we should remove this file from the hash.
5210 if ( not $had_breakpoints{$fn} &= (~1) ) {
5211 delete $had_breakpoints{$fn};
5213 } ## end for my $fn (keys %had_breakpoints)
5215 # Kill off all the other breakpoints that are waiting for files that
5216 # haven't been loaded yet.
5218 undef %postponed_file;
5219 undef %break_on_load;
5224 sub _delete_breakpoint_from_line {
5227 # Woops. This line wasn't breakable at all.
5228 die "Line $i not breakable.\n" if $dbline[$i] == 0;
5230 # Kill the condition, but leave any action.
5231 $dbline{$i} =~ s/\A[^\0]*//;
5233 # Remove the entry entirely if there's no action left.
5234 if ($dbline{$i} eq '') {
5235 _remove_breakpoint_entry($filename, $i);
5241 sub delete_breakpoint {
5244 # If we got a line, delete just that one.
5245 if ( defined($i) ) {
5246 _delete_breakpoint_from_line($i);
5248 # No line; delete them all.
5250 _delete_all_breakpoints();
5256 =head3 cmd_stop (command)
5258 This is meant to be part of the new command API, but it isn't called or used
5259 anywhere else in the debugger. XXX It is probably meant for use in development
5264 sub cmd_stop { # As on ^C, but not signal-safy.
5268 =head3 C<cmd_e> - threads
5270 Display the current thread id:
5274 This could be how (when implemented) to send commands to this thread id (e cmd)
5275 or that thread id (e tid cmd).
5282 unless (exists($INC{'threads.pm'})) {
5283 print "threads not loaded($ENV{PERL5DB_THREADED})
5284 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5286 my $tid = threads->tid;
5287 print "thread id: $tid\n";
5291 =head3 C<cmd_E> - list of thread ids
5293 Display the list of available thread ids:
5297 This could be used (when implemented) to send commands to all threads (E cmd).
5304 unless (exists($INC{'threads.pm'})) {
5305 print "threads not loaded($ENV{PERL5DB_THREADED})
5306 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5308 my $tid = threads->tid;
5309 print "thread ids: ".join(', ',
5310 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
5315 =head3 C<cmd_h> - help command (command)
5317 Does the work of either
5323 Showing all the debugger help
5327 Showing help for a specific command
5334 use vars qw($summary);
5339 # If we have no operand, assume null.
5340 my $line = shift || '';
5342 # 'h h'. Print the long-format help.
5343 if ( $line =~ /\Ah\s*\z/ ) {
5347 # 'h <something>'. Search for the command and print only its help.
5348 elsif ( my ($asked) = $line =~ /\A(\S.*)\z/ ) {
5350 # support long commands; otherwise bogus errors
5351 # happen when you ask for h on <CR> for example
5352 my $qasked = quotemeta($asked); # for searching; we don't
5353 # want to use it as a pattern.
5354 # XXX: finds CR but not <CR>
5356 # Search the help string for the command.
5358 $help =~ /^ # Start of a line
5360 (?:[IB]<) # Optional markup
5361 $qasked # The requested command
5366 # It's there; pull it out and print it.
5370 (?:[IB]<) # Optional markup
5371 $qasked # The command
5372 ([\s\S]*?) # Description line(s)
5373 \n) # End of last description line
5374 (?!\s) # Next line not starting with
5383 # Not found; not a debugger command.
5385 print_help("B<$asked> is not a debugger command.\n");
5387 } ## end elsif ($line =~ /^(\S.*)$/)
5389 # 'h' - print the summary help.
5391 print_help($summary);
5395 =head3 C<cmd_i> - inheritance display
5397 Display the (nested) parentage of the module or object given.
5404 foreach my $isa ( split( /\s+/, $line ) ) {
5406 ($isa) = DB::eval();
5413 defined( ${"$_\::VERSION"} )
5414 ? ' ' . ${"$_\::VERSION"}
5416 } @{mro::get_linear_isa(ref($isa) || $isa)}
5422 =head3 C<cmd_l> - list lines (command)
5424 Most of the command is taken up with transforming all the different line
5425 specification syntaxes into 'start-stop'. After that is done, the command
5426 runs a loop over C<@dbline> for the specified range of lines. It handles
5427 the printing of each line and any markers (C<==E<gt>> for current line,
5428 C<b> for break on this line, C<a> for action on this line, C<:> for this
5431 We save the last line listed in the C<$start> global for further listing
5437 my $current_line = $line;
5441 # If this is '-something', delete any spaces after the dash.
5442 $line =~ s/^-\s*$/-/;
5444 # If the line is '$something', assume this is a scalar containing a
5446 if ( $line =~ /^(\$.*)/s ) {
5448 # Set up for DB::eval() - evaluate in *user* context.
5451 my ($s) = DB::eval();
5453 # Ooops. Bad scalar.
5455 print {$OUT} "Error: $@\n";
5459 # Good scalar. If it's a reference, find what it points to.
5461 print {$OUT} "Interpreted as: $1 $s\n";
5464 # Call self recursively to really do the command.
5466 } ## end if ($line =~ /^(\$.*)/s)
5468 # l name. Try to find a sub by that name.
5469 elsif ( ($subname) = $line =~ /\A([\':A-Za-z_][\':\w]*(?:\[.*\])?)/s ) {
5473 $subname =~ s/\'/::/;
5475 # Put it in this package unless it starts with ::.
5476 $subname = $package . "::" . $subname unless $subname =~ /::/;
5478 # Put it in CORE::GLOBAL if t doesn't start with :: and
5479 # it doesn't live in this package and it lives in CORE::GLOBAL.
5480 $subname = "CORE::GLOBAL::$s"
5481 if not defined &$subname
5483 and defined &{"CORE::GLOBAL::$s"};
5485 # Put leading '::' names into 'main::'.
5486 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
5488 # Get name:start-stop from find_sub, and break this up at
5490 my @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
5492 # Pull off start-stop.
5493 my $subrange = pop @pieces;
5495 # If the name contained colons, the split broke it up.
5496 # Put it back together.
5497 $file = join( ':', @pieces );
5499 # If we're not in that file, switch over to it.
5500 if ( $file ne $filename ) {
5501 print $OUT "Switching to file '$file'.\n"
5502 unless $slave_editor;
5504 # Switch debugger's magic structures.
5505 *dbline = $main::{ '_<' . $file };
5508 } ## end if ($file ne $filename)
5510 # Subrange is 'start-stop'. If this is less than a window full,
5511 # swap it to 'start+', which will list a window from the start point.
5513 if ( eval($subrange) < -$window ) {
5514 $subrange =~ s/-.*/+/;
5517 # Call self recursively to list the range.
5519 cmd_l( 'l', $subrange );
5520 } ## end if ($subrange)
5524 print $OUT "Subroutine $subname not found.\n";
5526 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
5529 elsif ( $line !~ /\S/ ) {
5531 # Compute new range to list.
5532 $incr = $window - 1;
5533 $line = $start . '-' . ( $start + $incr );
5536 cmd_l( 'l', $line );
5539 # l [start]+number_of_lines
5540 elsif ( my ($new_start, $new_incr) = $line =~ /\A(\d*)\+(\d*)\z/ ) {
5542 # Don't reset start for 'l +nnn'.
5543 $start = $new_start if $new_start;
5545 # Increment for list. Use window size if not specified.
5546 # (Allows 'l +' to work.)
5548 $incr = $window - 1 unless $incr;
5550 # Create a line range we'll understand, and recurse to do it.
5551 $line = $start . '-' . ( $start + $incr );
5552 cmd_l( 'l', $line );
5553 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
5555 # l start-stop or l start,stop
5556 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) {
5558 # Determine end point; use end of file if not specified.
5559 my $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 );
5561 # Go on to the end, and then stop.
5562 $end = $max if $end > $max;
5564 # Determine start line.
5566 $i = $line if $i eq '.';
5570 # If we're running under a slave editor, force it to show the lines.
5571 if ($slave_editor) {
5572 print $OUT "\032\032$filename:$i:0\n";
5576 # We're doing it ourselves. We want to show the line and special
5578 # - the current line in execution
5579 # - whether a line is breakable or not
5580 # - whether a line has a break or not
5581 # - whether a line has an action or not
5583 for ( ; $i <= $end ; $i++ ) {
5585 # Check for breakpoints and actions.
5586 my ( $stop, $action );
5587 ( $stop, $action ) = split( /\0/, $dbline{$i} )
5590 # ==> if this is the current line in execution,
5591 # : if it's breakable.
5593 ( $i == $current_line and $filename eq $filename_ini )
5595 : ( $dbline[$i] + 0 ? ':' : ' ' );
5597 # Add break and action indicators.
5598 $arrow .= 'b' if $stop;
5599 $arrow .= 'a' if $action;
5602 print $OUT "$i$arrow\t", $dbline[$i];
5604 # Move on to the next line. Drop out on an interrupt.
5605 $i++, last if $signal;
5606 } ## end for (; $i <= $end ; $i++)
5608 # Line the prompt up; print a newline if the last line listed
5609 # didn't have a newline.
5610 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/;
5611 } ## end else [ if ($slave_editor)
5613 # Save the point we last listed to in case another relative 'l'
5614 # command is desired. Don't let it run off the end.
5616 $start = $max if $start > $max;
5617 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
5620 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5622 To list breakpoints, the command has to look determine where all of them are
5623 first. It starts a C<%had_breakpoints>, which tells us what all files have
5624 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5625 magic source and breakpoint data structures) to the file, and then look
5626 through C<%dbline> for lines with breakpoints and/or actions, listing them
5627 out. We look through C<%postponed> not-yet-compiled subroutines that have
5628 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5629 that have breakpoints.
5631 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5638 # If no argument, list everything. Pre-5.8.0 version always lists
5640 my $arg = shift || 'abw';
5641 if ($CommandSet ne '580')
5646 # See what is wanted.
5647 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0;
5648 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0;
5649 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0;
5651 # Breaks and actions are found together, so we look in the same place
5653 if ( $break_wanted or $action_wanted ) {
5655 # Look in all the files with breakpoints...
5656 for my $file ( keys %had_breakpoints ) {
5658 # Temporary switch to this file.
5659 local *dbline = $main::{ '_<' . $file };
5661 # Set up to look through the whole file.
5663 my $was; # Flag: did we print something
5666 # For each line in the file ...
5667 for my $i (1 .. $max) {
5669 # We've got something on this line.
5670 if ( defined $dbline{$i} ) {
5672 # Print the header if we haven't.
5673 print $OUT "$file:\n" unless $was++;
5676 print $OUT " $i:\t", $dbline[$i];
5678 # Pull out the condition and the action.
5679 my ( $stop, $action ) = split( /\0/, $dbline{$i} );
5681 # Print the break if there is one and it's wanted.
5682 print $OUT " break if (", $stop, ")\n"
5686 # Print the action if there is one and it's wanted.
5687 print $OUT " action: ", $action, "\n"
5691 # Quit if the user hit interrupt.
5693 } ## end if (defined $dbline{$i...
5694 } ## end for my $i (1 .. $max)
5695 } ## end for my $file (keys %had_breakpoints)
5696 } ## end if ($break_wanted or $action_wanted)
5698 # Look for breaks in not-yet-compiled subs:
5699 if ( %postponed and $break_wanted ) {
5700 print $OUT "Postponed breakpoints in subroutines:\n";
5702 for $subname ( keys %postponed ) {
5703 print $OUT " $subname\t$postponed{$subname}\n";
5706 } ## end if (%postponed and $break_wanted)
5708 # Find files that have not-yet-loaded breaks:
5709 my @have = map { # Combined keys
5710 keys %{ $postponed_file{$_} }
5711 } keys %postponed_file;
5713 # If there are any, list them.
5714 if ( @have and ( $break_wanted or $action_wanted ) ) {
5715 print $OUT "Postponed breakpoints in files:\n";
5716 for my $file ( keys %postponed_file ) {
5717 my $db = $postponed_file{$file};
5718 print $OUT " $file:\n";
5719 for my $line ( sort { $a <=> $b } keys %$db ) {
5720 print $OUT " $line:\n";
5721 my ( $stop, $action ) = split( /\0/, $$db{$line} );
5722 print $OUT " break if (", $stop, ")\n"
5725 print $OUT " action: ", $action, "\n"
5729 } ## end for $line (sort { $a <=>...
5731 } ## end for $file (keys %postponed_file)
5732 } ## end if (@have and ($break_wanted...
5733 if ( %break_on_load and $break_wanted ) {
5734 print {$OUT} "Breakpoints on load:\n";
5735 BREAK_ON_LOAD: for my $filename ( keys %break_on_load ) {
5736 print {$OUT} " $filename\n";
5737 last BREAK_ON_LOAD if $signal;
5739 } ## end if (%break_on_load and...
5740 if ($watch_wanted and ( $trace & 2 )) {
5741 print {$OUT} "Watch-expressions:\n" if @to_watch;
5742 TO_WATCH: for my $expr (@to_watch) {
5743 print {$OUT} " $expr\n";
5744 last TO_WATCH if $signal;
5749 =head3 C<cmd_M> - list modules (command)
5751 Just call C<list_modules>.
5761 =head3 C<cmd_o> - options (command)
5763 If this is just C<o> by itself, we list the current settings via
5764 C<dump_option>. If there's a nonblank value following it, we pass that on to
5765 C<parse_options> for processing.
5771 my $opt = shift || ''; # opt[=val]
5773 # Nonblank. Try to parse and process.
5774 if ( $opt =~ /^(\S.*)/ ) {
5778 # Blank. List the current option settings.
5786 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5788 Advises the user that the O command has been renamed.
5793 print $OUT "The old O command is now the o command.\n"; # hint
5794 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5795 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5798 =head3 C<cmd_v> - view window (command)
5800 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5801 move back a few lines to list the selected line in context. Uses C<cmd_l>
5802 to do the actual listing after figuring out the range of line to request.
5806 use vars qw($preview);
5812 # Extract the line to list around. (Astute readers will have noted that
5813 # this pattern will match whether or not a numeric line is specified,
5814 # which means that we'll always enter this loop (though a non-numeric
5815 # argument results in no action at all)).
5816 if ( $line =~ /^(\d*)$/ ) {
5818 # Total number of lines to list (a windowful).
5819 $incr = $window - 1;
5821 # Set the start to the argument given (if there was one).
5824 # Back up by the context amount.
5827 # Put together a linespec that cmd_l will like.
5828 $line = $start . '-' . ( $start + $incr );
5831 cmd_l( 'l', $line );
5832 } ## end if ($line =~ /^(\d*)$/)
5835 =head3 C<cmd_w> - add a watch expression (command)
5837 The 5.8 version of this command adds a watch expression if one is specified;
5838 it does nothing if entered with no operands.
5840 We extract the expression, save it, evaluate it in the user's context, and
5841 save the value. We'll re-evaluate it each time the debugger passes a line,
5842 and will stop (see the code at the top of the command loop) if the value
5843 of any of the expressions changes.
5847 sub _add_watch_expr {
5851 push @to_watch, $expr;
5853 # Parameterize DB::eval and call it to get the expression's value
5854 # in the user's context. This version can handle expressions which
5855 # return a list value.
5857 my ($val) = join( ' ', DB::eval() );
5858 $val = ( defined $val ) ? "'$val'" : 'undef';
5860 # Save the current value of the expression.
5861 push @old_watch, $val;
5863 # We are now watching expressions.
5872 # Null expression if no arguments.
5873 my $expr = shift || '';
5875 # If expression is not null ...
5876 if ( $expr =~ /\A\S/ ) {
5877 _add_watch_expr($expr);
5878 } ## end if ($expr =~ /^(\S.*)/)
5880 # You have to give one to get one.
5882 print $OUT "Adding a watch-expression requires an expression\n"; # hint
5888 =head3 C<cmd_W> - delete watch expressions (command)
5890 This command accepts either a watch expression to be removed from the list
5891 of watch expressions, or C<*> to delete them all.
5893 If C<*> is specified, we simply empty the watch expression list and the
5894 watch expression value list. We also turn off the bit that says we've got
5897 If an expression (or partial expression) is specified, we pattern-match
5898 through the expressions and remove the ones that match. We also discard
5899 the corresponding values. If no watch expressions are left, we turn off
5900 the I<watching expressions> bit.
5906 my $expr = shift || '';
5909 if ( $expr eq '*' ) {
5914 print $OUT "Deleting all watch expressions ...\n";
5917 @to_watch = @old_watch = ();
5920 # Delete one of them.
5921 elsif ( $expr =~ /^(\S.*)/ ) {
5923 # Where we are in the list.
5926 # For each expression ...
5927 foreach (@to_watch) {
5928 my $val = $to_watch[$i_cnt];
5930 # Does this one match the command argument?
5931 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
5932 # Yes. Turn it off, and its value too.
5933 splice( @to_watch, $i_cnt, 1 );
5934 splice( @old_watch, $i_cnt, 1 );
5937 } ## end foreach (@to_watch)
5939 # We don't bother to turn watching off because
5940 # a) we don't want to stop calling watchfunction() it it exists
5941 # b) foreach over a null list doesn't do anything anyway
5943 } ## end elsif ($expr =~ /^(\S.*)/)
5945 # No command arguments entered.
5948 "Deleting a watch-expression requires an expression, or '*' for all\n"
5953 ### END of the API section
5955 =head1 SUPPORT ROUTINES
5957 These are general support routines that are used in a number of places
5958 throughout the debugger.
5962 save() saves the user's versions of globals that would mess us up in C<@saved>,
5963 and installs the versions we like better.
5969 # Save eval failure, command failure, extended OS error, output field
5970 # separator, input record separator, output record separator and
5971 # the warning setting.
5972 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
5974 $, = ""; # output field separator is null string
5975 $/ = "\n"; # input record separator is newline
5976 $\ = ""; # output record separator is null string
5977 $^W = 0; # warnings are off
5980 =head2 C<print_lineinfo> - show where we are now
5982 print_lineinfo prints whatever it is that it is handed; it prints it to the
5983 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5984 us to feed line information to a slave editor without messing up the
5989 sub print_lineinfo {
5991 # Make the terminal sensible if we're not the primary debugger.
5992 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5996 } ## end sub print_lineinfo
5998 =head2 C<postponed_sub>
6000 Handles setting postponed breakpoints in subroutines once they're compiled.
6001 For breakpoints, we use C<DB::find_sub> to locate the source file and line
6002 range for the subroutine, then mark the file as having a breakpoint,
6003 temporarily switch the C<*dbline> glob over to the source file, and then
6004 search the given range of lines to find a breakable line. If we find one,
6005 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
6009 # The following takes its argument via $evalarg to preserve current @_
6013 # Get the subroutine name.
6014 my $subname = shift;
6016 # If this is a 'break +<n> if <condition>' ...
6017 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
6019 # If there's no offset, use '+0'.
6020 my $offset = $1 || 0;
6022 # find_sub's value is 'fullpath-filename:start-stop'. It's
6023 # possible that the filename might have colons in it too.
6024 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
6027 # We got the start line. Add the offset '+<n>' from
6028 # $postponed{subname}.
6031 # Switch to the file this sub is in, temporarily.
6032 local *dbline = $main::{ '_<' . $file };
6034 # No warnings, please.
6035 local $^W = 0; # != 0 is magical below
6037 # This file's got a breakpoint in it.
6038 $had_breakpoints{$file} |= 1;
6040 # Last line in file.
6043 # Search forward until we hit a breakable line or get to
6044 # the end of the file.
6045 ++$i until $dbline[$i] != 0 or $i >= $max;
6047 # Copy the breakpoint in and delete it from %postponed.
6048 $dbline{$i} = delete $postponed{$subname};
6051 # find_sub didn't find the sub.
6054 print $OUT "Subroutine $subname not found.\n";
6057 } ## end if ($postponed{$subname...
6058 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
6060 #print $OUT "In postponed_sub for '$subname'.\n";
6061 } ## end sub postponed_sub
6065 Called after each required file is compiled, but before it is executed;
6066 also called if the name of a just-compiled subroutine is a key of
6067 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
6068 etc.) into the just-compiled code.
6070 If this is a C<require>'d file, the incoming parameter is the glob
6071 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
6073 If it's a subroutine, the incoming parameter is the subroutine name.
6079 # If there's a break, process it.
6080 if ($ImmediateStop) {
6082 # Right, we've stopped. Turn it off.
6085 # Enter the command loop when DB::DB gets called.
6089 # If this is a subroutine, let postponed_sub() deal with it.
6090 if (ref(\$_[0]) ne 'GLOB') {
6091 return postponed_sub(@_);
6094 # Not a subroutine. Deal with the file.
6095 local *dbline = shift;
6096 my $filename = $dbline;
6097 $filename =~ s/^_<//;
6099 $signal = 1, print $OUT "'$filename' loaded...\n"
6100 if $break_on_load{$filename};
6101 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
6103 # Do we have any breakpoints to put in this file?
6104 return unless $postponed_file{$filename};
6106 # Yes. Mark this file as having breakpoints.
6107 $had_breakpoints{$filename} |= 1;
6109 # "Cannot be done: insufficient magic" - we can't just put the
6110 # breakpoints saved in %postponed_file into %dbline by assigning
6111 # the whole hash; we have to do it one item at a time for the
6112 # breakpoints to be set properly.
6113 #%dbline = %{$postponed_file{$filename}};
6115 # Set the breakpoints, one at a time.
6118 for $key ( keys %{ $postponed_file{$filename} } ) {
6120 # Stash the saved breakpoint into the current file's magic line array.
6121 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
6124 # This file's been compiled; discard the stored breakpoints.
6125 delete $postponed_file{$filename};
6127 } ## end sub postponed
6131 C<dumpit> is the debugger's wrapper around dumpvar.pl.
6133 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
6134 a reference to a variable (the thing to be dumped) as its input.
6136 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
6137 the currently-selected filehandle, thank you very much). The current
6138 values of the package globals C<$single> and C<$trace> are backed up in
6139 lexicals, and they are turned off (this keeps the debugger from trying
6140 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
6141 preserve its current value and it is set to zero to prevent entry/exit
6142 messages from printing, and C<$doret> is localized as well and set to -2 to
6143 prevent return values from being shown.
6145 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
6146 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
6147 installed version in C<@INC>, yours will be used instead. Possible security
6150 It then checks to see if the subroutine C<main::dumpValue> is now defined
6151 it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
6152 localizes the globals necessary for things to be sane when C<main::dumpValue()>
6153 is called, and picks up the variable to be dumped from the parameter list.
6155 It checks the package global C<%options> to see if there's a C<dumpDepth>
6156 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
6157 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
6158 structure: -1 means dump everything.
6160 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
6163 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
6164 and we then return to the caller.
6170 # Save the current output filehandle and switch to the one
6171 # passed in as the first parameter.
6172 my $savout = select(shift);
6174 # Save current settings of $single and $trace, and then turn them off.
6175 my $osingle = $single;
6176 my $otrace = $trace;
6177 $single = $trace = 0;
6179 # XXX Okay, what do $frame and $doret do, again?
6183 # Load dumpvar.pl unless we've already got the sub we need from it.
6184 unless ( defined &main::dumpValue ) {
6185 do 'dumpvar.pl' or die $@;
6188 # If the load succeeded (or we already had dumpvalue()), go ahead
6190 if ( defined &main::dumpValue ) {
6195 my $maxdepth = shift || $option{dumpDepth};
6196 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
6197 main::dumpValue( $v, $maxdepth );
6198 } ## end if (defined &main::dumpValue)
6200 # Oops, couldn't load dumpvar.pl.
6203 print $OUT "dumpvar.pl not available.\n";
6206 # Reset $single and $trace to their old values.
6210 # Restore the old filehandle.
6214 =head2 C<print_trace>
6216 C<print_trace>'s job is to print a stack trace. It does this via the
6217 C<dump_trace> routine, which actually does all the ferreting-out of the
6218 stack trace data. C<print_trace> takes care of formatting it nicely and
6219 printing it to the proper filehandle.
6227 The filehandle to print to.
6231 How many frames to skip before starting trace.
6235 How many frames to print.
6239 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
6243 The original comment below seems to be noting that the traceback may not be
6244 correct if this routine is called in a tied method.
6248 # Tied method do not create a context, so may get wrong message:
6254 # If this is going to a slave editor, but we're not the primary
6255 # debugger, reset it first.
6257 if $fh eq $LINEINFO # slave editor
6258 and $LINEINFO eq $OUT # normal output
6259 and $term_pid != $$; # not the primary
6261 # Collect the actual trace information to be formatted.
6262 # This is an array of hashes of subroutine call info.
6263 my @sub = dump_trace( $_[0] + 1, $_[1] );
6265 # Grab the "short report" flag from @_.
6266 my $short = $_[2]; # Print short report, next one for sub name
6268 # Run through the traceback info, format it, and print it.
6270 for my $i (0 .. $#sub) {
6272 # Drop out if the user has lost interest and hit control-C.
6275 # Set the separator so arrys print nice.
6278 # Grab and stringify the arguments if they are there.
6280 defined $sub[$i]{args}
6281 ? "(@{ $sub[$i]{args} })"
6284 # Shorten them up if $maxtrace says they're too long.
6285 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
6286 if length $args > $maxtrace;
6288 # Get the file name.
6289 my $file = $sub[$i]{file};
6291 # Put in a filename header if short is off.
6292 $file = $file eq '-e' ? $file : "file '$file'" unless $short;
6294 # Get the actual sub's name, and shorten to $maxtrace's requirement.
6295 $s = $sub[$i]{'sub'};
6296 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
6298 # Short report uses trimmed file and sub names.
6300 my $sub = @_ >= 4 ? $_[3] : $s;
6301 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
6302 } ## end if ($short)
6304 # Non-short report includes full names.
6306 print $fh "$sub[$i]{context} = $s$args"
6307 . " called from $file"
6308 . " line $sub[$i]{line}\n";
6310 } ## end for my $i (0 .. $#sub)
6311 } ## end sub print_trace
6313 =head2 dump_trace(skip[,count])
6315 Actually collect the traceback information available via C<caller()>. It does
6316 some filtering and cleanup of the data, but mostly it just collects it to
6317 make C<print_trace()>'s job easier.
6319 C<skip> defines the number of stack frames to be skipped, working backwards
6320 from the most current. C<count> determines the total number of frames to
6321 be returned; all of them (well, the first 10^9) are returned if C<count>
6324 This routine returns a list of hashes, from most-recent to least-recent
6325 stack frame. Each has the following keys and values:
6329 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
6331 =item * C<sub> - subroutine name, or C<eval> information
6333 =item * C<args> - undef, or a reference to an array of arguments
6335 =item * C<file> - the file in which this item was defined (if any)
6337 =item * C<line> - the line on which it was defined
6345 # How many levels to skip.
6348 # How many levels to show. (1e9 is a cheap way of saying "all of them";
6349 # it's unlikely that we'll have more than a billion stack frames. If you
6350 # do, you've got an awfully big machine...)
6351 my $count = shift || 1e9;
6353 # We increment skip because caller(1) is the first level *back* from
6354 # the current one. Add $skip to the count of frames so we have a
6355 # simple stop criterion, counting from $skip to $count+$skip.
6359 # These variables are used to capture output from caller();
6360 my ( $p, $file, $line, $sub, $h, $context );
6362 my ( $e, $r, @a, @sub, $args );
6364 # XXX Okay... why'd we do that?
6365 my $nothard = not $frame & 8;
6368 # Do not want to trace this.
6369 my $otrace = $trace;
6372 # Start out at the skip count.
6373 # If we haven't reached the number of frames requested, and caller() is
6374 # still returning something, stay in the loop. (If we pass the requested
6375 # number of stack frames, or we run out - caller() returns nothing - we
6377 # Up the stack frame index to go back one more level each time.
6381 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
6386 # Go through the arguments and save them for later.
6388 for my $arg (@args) {
6390 if ( not defined $arg ) { # undefined parameter
6394 elsif ( $nothard and tied $arg ) { # tied parameter
6397 elsif ( $nothard and $type = ref $arg ) { # reference
6398 push @a, "ref($type)";
6400 else { # can be stringified
6402 "$arg"; # Safe to stringify now - should not call f().
6404 # Backslash any single-quotes or backslashes.
6407 # Single-quote it unless it's a number or a colon-separated
6410 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
6412 # Turn high-bit characters into meta-whatever.
6413 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
6415 # Turn control characters into ^-whatever.
6416 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
6419 } ## end else [ if (not defined $arg)
6420 } ## end for $arg (@args)
6422 # If context is true, this is array (@)context.
6423 # If context is false, this is scalar ($) context.
6424 # If neither, context isn't defined. (This is apparently a 'can't
6426 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
6428 # if the sub has args ($h true), make an anonymous array of the
6430 $args = $h ? [@a] : undef;
6432 # remove trailing newline-whitespace-semicolon-end of line sequence
6433 # from the eval text, if any.
6434 $e =~ s/\n\s*\;\s*\Z// if $e;
6436 # Escape backslashed single-quotes again if necessary.
6437 $e =~ s/([\\\'])/\\$1/g if $e;
6439 # if the require flag is true, the eval text is from a require.
6441 $sub = "require '$e'";
6444 # if it's false, the eval text is really from an eval.
6445 elsif ( defined $r ) {
6449 # If the sub is '(eval)', this is a block eval, meaning we don't
6450 # know what the eval'ed text actually was.
6451 elsif ( $sub eq '(eval)' ) {
6452 $sub = "eval {...}";
6455 # Stick the collected information into @sub as an anonymous hash.
6459 context => $context,
6467 # Stop processing frames if the user hit control-C.
6469 } ## end for ($i = $skip ; $i < ...
6471 # Restore the trace value again.
6474 } ## end sub dump_trace
6478 C<action()> takes input provided as the argument to an add-action command,
6479 either pre- or post-, and makes sure it's a complete command. It doesn't do
6480 any fancy parsing; it just keeps reading input until it gets a string
6481 without a trailing backslash.
6488 while ( $action =~ s/\\$// ) {
6490 # We have a backslash on the end. Read more.
6492 } ## end while ($action =~ s/\\$//)
6494 # Return the assembled action.
6500 This routine mostly just packages up a regular expression to be used
6501 to check that the thing it's being matched against has properly-matched
6504 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
6505 speeds things up by only creating the qr//'ed expression once; if it's
6506 already defined, we don't try to define it again. A speed hack.
6510 use vars qw($balanced_brace_re);
6514 # I hate using globals!
6515 $balanced_brace_re ||= qr{
6518 (?> [^{}] + ) # Non-parens without backtracking
6520 (??{ $balanced_brace_re }) # Group with matching parens
6524 return $_[0] !~ m/$balanced_brace_re/;
6525 } ## end sub unbalanced
6529 C<gets()> is a primitive (very primitive) routine to read continuations.
6530 It was devised for reading continuations for actions.
6531 it just reads more input with C<readline()> and returns it.
6536 return DB::readline("cont: ");
6539 =head2 C<_db_system()> - handle calls to<system()> without messing up the debugger
6541 The C<system()> function assumes that it can just go ahead and use STDIN and
6542 STDOUT, but under the debugger, we want it to use the debugger's input and
6545 C<_db_system()> socks away the program's STDIN and STDOUT, and then substitutes
6546 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
6547 and then puts everything back again.
6553 # We save, change, then restore STDIN and STDOUT to avoid fork() since
6554 # some non-Unix systems can do system() but have problems with fork().
6555 open( SAVEIN, "<&STDIN" ) || db_warn("Can't save STDIN");
6556 open( SAVEOUT, ">&STDOUT" ) || db_warn("Can't save STDOUT");
6557 open( STDIN, "<&IN" ) || db_warn("Can't redirect STDIN");
6558 open( STDOUT, ">&OUT" ) || db_warn("Can't redirect STDOUT");
6560 # XXX: using csh or tcsh destroys sigint retvals!
6562 open( STDIN, "<&SAVEIN" ) || db_warn("Can't restore STDIN");
6563 open( STDOUT, ">&SAVEOUT" ) || db_warn("Can't restore STDOUT");
6567 # most of the $? crud was coping with broken cshisms
6569 db_warn( "(Command exited ", ( $? >> 8 ), ")\n" );
6573 "(Command died of SIG#",
6575 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6584 *system = \&_db_system;
6586 =head1 TTY MANAGEMENT
6588 The subs here do some of the terminal management for multiple debuggers.
6592 Top-level function called when we want to set up a new terminal for use
6595 If the C<noTTY> debugger option was set, we'll either use the terminal
6596 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6597 to find one. If we're a forked debugger, we call C<resetterm> to try to
6598 get a whole new terminal if we can.
6600 In either case, we set up the terminal next. If the C<ReadLine> option was
6601 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6602 the appropriate attributes. We then
6606 use vars qw($ornaments);
6607 use vars qw($rl_attribs);
6611 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6614 require Term::ReadLine;
6616 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6619 my ( $i, $o ) = split $tty, /,/;
6620 $o = $i unless defined $o;
6621 open( IN, "<$i" ) or die "Cannot open TTY '$i' for read: $!";
6622 open( OUT, ">$o" ) or die "Cannot open TTY '$o' for write: $!";
6628 # We don't have a TTY - try to find one via Term::Rendezvous.
6630 require Term::Rendezvous;
6632 # See if we have anything to pass to Term::Rendezvous.
6633 # Use $HOME/.perldbtty$$ if not.
6634 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6636 # Rendezvous and get the filehandles.
6637 my $term_rv = Term::Rendezvous->new( $rv );
6639 $OUT = $term_rv->OUT;
6640 } ## end else [ if ($tty)
6641 } ## end if ($notty)
6643 # We're a daughter debugger. Try to fork off another TTY.
6644 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6648 # If we shouldn't use Term::ReadLine, don't.
6650 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6653 # We're using Term::ReadLine. Get all the attributes for this terminal.
6655 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6657 $rl_attribs = $term->Attribs;
6658 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6659 if defined $rl_attribs->{basic_word_break_characters}
6660 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6661 $rl_attribs->{special_prefixes} = '$@&%';
6662 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6663 $rl_attribs->{completion_function} = \&db_complete;
6664 } ## end else [ if (!$rl)
6666 # Set up the LINEINFO filehandle.
6667 $LINEINFO = $OUT unless defined $LINEINFO;
6668 $lineinfo = $console unless defined $lineinfo;
6674 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6675 $term->SetHistory(@hist);
6678 # XXX Ornaments are turned on unconditionally, which is not
6679 # always a good thing.
6680 ornaments($ornaments) if defined $ornaments;
6682 } ## end sub setterm
6685 $histfile //= option_val("HistFile", undef);
6686 return unless defined $histfile;
6687 open my $fh, "<", $histfile or return;
6698 return unless defined $histfile;
6699 eval { require File::Path } or return;
6700 eval { require File::Basename } or return;
6701 File::Path::mkpath(File::Basename::dirname($histfile));
6702 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6703 $histsize //= option_val("HistSize",100);
6704 my @copy = grep { $_ ne '?' } @hist;
6705 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6706 for ($start .. $#copy) {
6707 print $fh "$copy[$_]\n";
6709 close $fh or die "Could not write '$histfile': $!";
6712 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6714 When the process being debugged forks, or the process invokes a command
6715 via C<system()> which starts a new debugger, we need to be able to get a new
6716 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6717 fight over the terminal, and you can never quite be sure who's going to get the
6718 input you're typing.
6720 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6721 is tasked with doing all the necessary operating system mojo to get a new
6722 TTY (and probably another window) and to direct the new debugger to read and
6725 The debugger provides C<get_fork_TTY> functions which work for TCP
6726 socket servers, X11, OS/2, and Mac OS X. Other systems are not
6727 supported. You are encouraged to write C<get_fork_TTY> functions which
6728 work for I<your> platform and contribute them.
6730 =head3 C<socket_get_fork_TTY>
6734 sub connect_remoteport {
6737 my $socket = IO::Socket::INET->new(
6739 PeerAddr => $remoteport,
6743 die "Unable to connect to remote host: $remoteport\n";
6748 sub socket_get_fork_TTY {
6749 $tty = $LINEINFO = $IN = $OUT = connect_remoteport();
6751 # Do I need to worry about setting $term?
6753 reset_IN_OUT( $IN, $OUT );
6757 =head3 C<xterm_get_fork_TTY>
6759 This function provides the C<get_fork_TTY> function for X11. If a
6760 program running under the debugger forks, a new <xterm> window is opened and
6761 the subsidiary debugger is directed there.
6763 The C<open()> call is of particular note here. We have the new C<xterm>
6764 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6765 command (which prints the device name of the TTY we'll want to use for input
6766 and output to STDOUT, then C<sleep> for a very long time, routing this output
6767 to file number 3. This way we can simply read from the <XT> filehandle (which
6768 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6770 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6775 sub xterm_get_fork_TTY {
6776 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6778 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6781 # Get the output from 'tty' and clean it up a little.
6785 $pidprompt = ''; # Shown anyway in titlebar
6787 # We need $term defined or we can not switch to the newly created xterm
6788 if ($tty ne '' && !defined $term) {
6789 require Term::ReadLine;
6791 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6794 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6797 # There's our new TTY.
6799 } ## end sub xterm_get_fork_TTY
6801 =head3 C<os2_get_fork_TTY>
6803 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6807 # This example function resets $IN, $OUT itself
6809 sub os2_get_fork_TTY { # A simplification of the following (and works without):
6811 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6812 my %opt = ( title => "Daughter Perl debugger $pids $name",
6813 ($rl ? (read_by_key => 1) : ()) );
6814 require OS2::Process;
6815 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
6817 $pidprompt = ''; # Shown anyway in titlebar
6818 reset_IN_OUT($in, $out);
6820 return ''; # Indicate that reset_IN_OUT is called
6821 } ## end sub os2_get_fork_TTY
6823 =head3 C<macosx_get_fork_TTY>
6825 The Mac OS X version uses AppleScript to tell Terminal.app to create
6830 # Notes about Terminal.app's AppleScript support,
6831 # (aka things that might break in future OS versions).
6833 # The "do script" command doesn't return a reference to the new window
6834 # it creates, but since it appears frontmost and windows are enumerated
6835 # front to back, we can use "first window" === "window 1".
6837 # Since "do script" is implemented by supplying the argument (plus a
6838 # return character) as terminal input, there's a potential race condition
6839 # where the debugger could beat the shell to reading the command.
6840 # To prevent this, we wait for the screen to clear before proceeding.
6843 # There's no direct accessor for the tty device name, so we fiddle
6844 # with the window title options until it says what we want.
6847 # There _is_ a direct accessor for the tty device name, _and_ there's
6848 # a new possible component of the window title (the name of the settings
6849 # set). A separate version is needed.
6851 my @script_versions=
6853 ([237, <<'__LEOPARD__'],
6854 tell application "Terminal"
6855 do script "clear;exec sleep 100000"
6856 tell first tab of first window
6858 set custom title to "forked perl debugger"
6859 set title displays custom title to true
6860 repeat while (length of first paragraph of (get contents)) > 0
6868 [100, <<'__JAGUAR_TIGER__'],
6869 tell application "Terminal"
6870 do script "clear;exec sleep 100000"
6872 set title displays shell path to false
6873 set title displays window size to false
6874 set title displays file name to false
6875 set title displays device name to true
6876 set title displays custom title to true
6877 set custom title to ""
6878 copy "/dev/" & name to thetty
6879 set custom title to "forked perl debugger"
6880 repeat while (length of first paragraph of (get contents)) > 0
6890 sub macosx_get_fork_TTY
6892 my($version,$script,$pipe,$tty);
6894 return unless $version=$ENV{TERM_PROGRAM_VERSION};
6895 foreach my $entry (@script_versions) {
6896 if ($version>=$entry->[0]) {
6897 $script=$entry->[1];
6901 return unless defined($script);
6902 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
6903 $tty=readline($pipe);
6905 return unless defined($tty) && $tty =~ m(^/dev/);
6910 =head2 C<create_IN_OUT($flags)>
6912 Create a new pair of filehandles, pointing to a new TTY. If impossible,
6913 try to diagnose why.
6919 =item * 1 - Don't know how to create a new TTY.
6921 =item * 2 - Debugger has forked, but we can't get a new TTY.
6923 =item * 4 - standard debugger startup is happening.
6929 use vars qw($fork_TTY);
6931 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
6933 # If we know how to get a new TTY, do it! $in will have
6934 # the TTY name if get_fork_TTY works.
6935 my $in = get_fork_TTY(@_) if defined &get_fork_TTY;
6937 # It used to be that
6938 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
6940 if ( not defined $in ) {
6943 # We don't know how.
6944 print_help(<<EOP) if $why == 1;
6945 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6949 print_help(<<EOP) if $why == 2;
6950 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6951 This may be an asynchronous session, so the parent debugger may be active.
6954 # Note that both debuggers are fighting over the same input.
6955 print_help(<<EOP) if $why != 4;
6956 Since two debuggers fight for the same TTY, input is severely entangled.
6960 I know how to switch the output to a different window in xterms, OS/2
6961 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
6962 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
6963 B<DB::get_fork_TTY()> returning this.
6965 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6966 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6969 } ## end if (not defined $in)
6970 elsif ( $in ne '' ) {
6974 $console = ''; # Indicate no need to open-from-the-console
6977 } ## end sub create_IN_OUT
6981 Handles rejiggering the prompt when we've forked off a new debugger.
6983 If the new debugger happened because of a C<system()> that invoked a
6984 program under the debugger, the arrow between the old pid and the new
6985 in the prompt has I<two> dashes instead of one.
6987 We take the current list of pids and add this one to the end. If there
6988 isn't any list yet, we make one up out of the initial pid associated with
6989 the terminal and our new pid, sticking an arrow (either one-dashed or
6990 two dashed) in between them.
6992 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6993 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6998 sub resetterm { # We forked, so we need a different TTY
7000 # Needs to be passed to create_IN_OUT() as well.
7003 # resetterm(2): got in here because of a system() starting a debugger.
7004 # resetterm(1): just forked.
7005 my $systemed = $in > 1 ? '-' : '';
7007 # If there's already a list of pids, add this to the end.
7009 $pids =~ s/\]/$systemed->$$]/;
7012 # No pid list. Time to make one.
7014 $pids = "[$term_pid->$$]";
7017 # The prompt we're going to be using for this debugger.
7020 # We now 0wnz this terminal.
7023 # Just return if we're not supposed to try to create a new TTY.
7024 return unless $CreateTTY & $in;
7026 # Try to create a new IN/OUT pair.
7028 } ## end sub resetterm
7032 First, we handle stuff in the typeahead buffer. If there is any, we shift off
7033 the next line, print a message saying we got it, add it to the terminal
7034 history (if possible), and return it.
7036 If there's nothing in the typeahead buffer, check the command filehandle stack.
7037 If there are any filehandles there, read from the last one, and return the line
7038 if we got one. If not, we pop the filehandle off and close it, and try the
7039 next one up the stack.
7041 If we've emptied the filehandle stack, we check to see if we've got a socket
7042 open, and we read that and return it if we do. If we don't, we just call the
7043 core C<readline()> and return its value.
7049 # Localize to prevent it from being smashed in the program being debugged.
7052 # If there are stacked filehandles to read from ...
7053 # (Handle it before the typeahead, because we may call source/etc. from
7057 # Read from the last one in the stack.
7058 my $line = CORE::readline( $cmdfhs[-1] );
7060 # If we got a line ...
7062 ? ( print $OUT ">> $line" and return $line ) # Echo and return
7063 : close pop @cmdfhs; # Pop and close
7064 } ## end while (@cmdfhs)
7066 # Pull a line out of the typeahead if there's stuff there.
7069 # How many lines left.
7070 my $left = @typeahead;
7072 # Get the next line.
7073 my $got = shift @typeahead;
7075 # Print a message saying we got input from the typeahead.
7077 print $OUT "auto(-$left)", shift, $got, "\n";
7079 # Add it to the terminal history (if possible).
7080 $term->AddHistory($got)
7082 and defined $term->Features->{addHistory};
7084 } ## end if (@typeahead)
7086 # We really need to read some input. Turn off entry/exit trace and
7087 # return value printing.
7091 # Nothing on the filehandle stack. Socket?
7092 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
7094 # Send anything we have to send.
7095 $OUT->write( join( '', @_ ) );
7097 # Receive anything there is to receive.
7102 while ($first_time or (length($buf) && ($stuff .= $buf) !~ /\n/))
7105 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
7106 # XXX Don't know. You tell me.
7111 } ## end if (ref $OUT and UNIVERSAL::isa...
7113 # No socket. Just read from the terminal.
7115 return $term->readline(@_);
7117 } ## end sub readline
7119 =head1 OPTIONS SUPPORT ROUTINES
7121 These routines handle listing and setting option values.
7123 =head2 C<dump_option> - list the current value of an option setting
7125 This routine uses C<option_val> to look up the value for an option.
7126 It cleans up escaped single-quotes and then displays the option and
7132 my ( $opt, $val ) = @_;
7133 $val = option_val( $opt, 'N/A' );
7134 $val =~ s/([\\\'])/\\$1/g;
7135 printf $OUT "%20s = '%s'\n", $opt, $val;
7136 } ## end sub dump_option
7138 sub options2remember {
7139 foreach my $k (@RememberOnROptions) {
7140 $option{$k} = option_val( $k, 'N/A' );
7145 =head2 C<option_val> - find the current value of an option
7147 This can't just be a simple hash lookup because of the indirect way that
7148 the option values are stored. Some are retrieved by calling a subroutine,
7149 some are just variables.
7151 You must supply a default value to be used in case the option isn't set.
7156 my ( $opt, $default ) = @_;
7159 # Does this option exist, and is it a variable?
7160 # If so, retrieve the value via the value in %optionVars.
7161 if ( defined $optionVars{$opt}
7162 and defined ${ $optionVars{$opt} } )
7164 $val = ${ $optionVars{$opt} };
7167 # Does this option exist, and it's a subroutine?
7168 # If so, call the subroutine via the ref in %optionAction
7169 # and capture the value.
7170 elsif ( defined $optionAction{$opt}
7171 and defined &{ $optionAction{$opt} } )
7173 $val = &{ $optionAction{$opt} }();
7176 # If there's an action or variable for the supplied option,
7177 # but no value was set, use the default.
7178 elsif (defined $optionAction{$opt} and not defined $option{$opt}
7179 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
7184 # Otherwise, do the simple hash lookup.
7186 $val = $option{$opt};
7189 # If the value isn't defined, use the default.
7190 # Then return whatever the value is.
7191 $val = $default unless defined $val;
7193 } ## end sub option_val
7195 =head2 C<parse_options>
7197 Handles the parsing and execution of option setting/displaying commands.
7199 An option entered by itself is assumed to be I<set me to 1> (the default value)
7200 if the option is a boolean one. If not, the user is prompted to enter a valid
7201 value or to query the current value (via C<option? >).
7203 If C<option=value> is entered, we try to extract a quoted string from the
7204 value (if it is quoted). If it's not, we just use the whole value as-is.
7206 We load any modules required to service this option, and then we set it: if
7207 it just gets stuck in a variable, we do that; if there's a subroutine to
7208 handle setting the option, we call that.
7210 Finally, if we're running in interactive mode, we display the effect of the
7211 user's command back to the terminal, skipping this if we're setting things
7212 during initialization.
7222 # These options need a value. Don't allow them to be clobbered by accident.
7223 my %opt_needs_val = map { ( $_ => 1 ) } qw{
7224 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
7225 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
7228 while (length($s)) {
7231 # Clean off excess leading whitespace.
7232 $s =~ s/^\s+// && next;
7234 # Options are always all word characters, followed by a non-word
7236 if ($s !~ s/^(\w+)(\W?)//) {
7237 print {$OUT} "Invalid option '$s'\n";
7240 my ( $opt, $sep ) = ( $1, $2 );
7242 # Make sure that such an option exists.
7243 my $matches = ( grep { /^\Q$opt/ && ( $option = $_ ) } @options )
7244 || ( grep { /^\Q$opt/i && ( $option = $_ ) } @options );
7247 print {$OUT} "Unknown option '$opt'\n";
7251 print {$OUT} "Ambiguous option '$opt'\n";
7256 # '?' as separator means query, but must have whitespace after it.
7257 if ( "?" eq $sep ) {
7259 print {$OUT} "Option query '$opt?' followed by non-space '$s'\n" ;
7264 #&dump_option($opt);
7265 } ## end if ("?" eq $sep)
7267 # Separator is whitespace (or just a carriage return).
7268 # They're going for a default, which we assume is 1.
7269 elsif ( $sep !~ /\S/ ) {
7271 $val = "1"; # this is an evil default; make 'em set it!
7274 # Separator is =. Trying to set a value.
7275 elsif ( $sep eq "=" ) {
7277 # If quoted, extract a quoted string.
7278 if ($s =~ s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
7280 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
7283 # Not quoted. Use the whole thing. Warn about 'option='.
7287 print OUT qq(Option better cleared using $opt=""\n)
7289 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
7291 } ## end elsif ($sep eq "=")
7293 # "Quoted" with [], <>, or {}.
7294 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
7296 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
7297 $s =~ s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
7298 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last;
7299 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
7300 } ## end else [ if ("?" eq $sep)
7302 # Exclude non-booleans from getting set to 1 by default.
7303 if ( $opt_needs_val{$option} && $val_defaulted ) {
7304 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
7306 "Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n";
7308 } ## end if ($opt_needs_val{$option...
7310 # Save the option value.
7311 $option{$option} = $val if defined $val;
7313 # Load any module that this option requires.
7314 if ( defined($optionRequire{$option}) && defined($val) ) {
7318 require '$optionRequire{$option}';
7320 } || die $@ # XXX: shouldn't happen
7324 # Stick it in the proper variable if it goes in a variable.
7325 if (defined($optionVars{$option}) && defined($val)) {
7326 ${ $optionVars{$option} } = $val;
7329 # Call the appropriate sub if it gets set via sub.
7330 if (defined($optionAction{$option})
7331 && defined (&{ $optionAction{$option} })
7334 &{ $optionAction{$option} }($val);
7337 # Not initialization - echo the value we set it to.
7338 dump_option($option) if ($OUT ne \*STDERR);
7339 } ## end while (length)
7340 } ## end sub parse_options
7342 =head1 RESTART SUPPORT
7344 These routines are used to store (and restore) lists of items in environment
7345 variables during a restart.
7349 Set_list packages up items to be stored in a set of environment variables
7350 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
7351 the values). Values outside the standard ASCII charset are stored by encoding
7352 then as hexadecimal values.
7357 my ( $stem, @list ) = @_;
7360 # VAR_n: how many we have. Scalar assignment gets the number of items.
7361 $ENV{"${stem}_n"} = @list;
7363 # Grab each item in the list, escape the backslashes, encode the non-ASCII
7364 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
7365 for my $i ( 0 .. $#list ) {
7367 $val =~ s/\\/\\\\/g;
7368 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
7369 $ENV{"${stem}_$i"} = $val;
7370 } ## end for $i (0 .. $#list)
7371 } ## end sub set_list
7375 Reverse the set_list operation: grab VAR_n to see how many we should be getting
7376 back, and then pull VAR_0, VAR_1. etc. back out.
7383 my $n = delete $ENV{"${stem}_n"};
7385 for my $i ( 0 .. $n - 1 ) {
7386 $val = delete $ENV{"${stem}_$i"};
7387 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
7391 } ## end sub get_list
7393 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
7397 The C<catch()> subroutine is the essence of fast and low-impact. We simply
7398 set an already-existing global scalar variable to a constant value. This
7399 avoids allocating any memory possibly in the middle of something that will
7400 get all confused if we do, particularly under I<unsafe signals>.
7406 return; # Put nothing on the stack - malloc/free land!
7411 C<warn> emits a warning, by joining together its arguments and printing
7412 them, with couple of fillips.
7414 If the composited message I<doesn't> end with a newline, we automatically
7415 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
7416 to be set to the filehandle to be used to output warnings; it makes no
7417 assumptions about what filehandles are available.
7422 my ($msg) = join( "", @_ );
7423 $msg .= ": $!\n" unless $msg =~ /\n$/;
7430 =head1 INITIALIZATION TTY SUPPORT
7432 =head2 C<reset_IN_OUT>
7434 This routine handles restoring the debugger's input and output filehandles
7435 after we've tried and failed to move them elsewhere. In addition, it assigns
7436 the debugger's output filehandle to $LINEINFO if it was already open there.
7441 my $switch_li = $LINEINFO eq $OUT;
7443 # If there's a term and it's able to get a new tty, try to get one.
7444 if ( $term and $term->Features->{newTTY} ) {
7445 ( $IN, $OUT ) = ( shift, shift );
7446 $term->newTTY( $IN, $OUT );
7449 # This term can't get a new tty now. Better luck later.
7451 _db_warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n");
7454 # Set the filehndles up as they were.
7456 ( $IN, $OUT ) = ( shift, shift );
7459 # Unbuffer the output filehandle.
7462 # Point LINEINFO to the same output filehandle if it was there before.
7463 $LINEINFO = $OUT if $switch_li;
7464 } ## end sub reset_IN_OUT
7466 =head1 OPTION SUPPORT ROUTINES
7468 The following routines are used to process some of the more complicated
7473 Sets the input and output filehandles to the specified files or pipes.
7474 If the terminal supports switching, we go ahead and do it. If not, and
7475 there's already a terminal in place, we save the information to take effect
7478 If there's no terminal yet (for instance, during debugger initialization),
7479 we go ahead and set C<$console> and C<$tty> to the file indicated.
7485 if ( @_ and $term and $term->Features->{newTTY} ) {
7487 # This terminal supports switching to a new TTY.
7488 # Can be a list of two files, or on string containing both names,
7490 # XXX Should this perhaps be an assignment from @_?
7491 my ( $in, $out ) = shift;
7494 # Split list apart if supplied.
7495 ( $in, $out ) = split /,/, $in, 2;
7499 # Use the same file for both input and output.
7503 # Open file onto the debugger's filehandles, if you can.
7504 open IN, $in or die "cannot open '$in' for read: $!";
7505 open OUT, ">$out" or die "cannot open '$out' for write: $!";
7507 # Swap to the new filehandles.
7508 reset_IN_OUT( \*IN, \*OUT );
7510 # Save the setting for later.
7512 } ## end if (@_ and $term and $term...
7514 # Terminal doesn't support new TTY, or doesn't support readline.
7515 # Can't do it now, try restarting.
7517 _db_warn("Too late to set TTY, enabled on next 'R'!\n");
7520 # Useful if done through PERLDB_OPTS:
7521 $console = $tty = shift if @_;
7523 # Return whatever the TTY is.
7529 Sets the C<$notty> global, controlling whether or not the debugger tries to
7530 get a terminal to read from. If called after a terminal is already in place,
7531 we save the value to use it if we're restarted.
7537 _db_warn("Too late to set noTTY, enabled on next 'R'!\n") if @_;
7539 $notty = shift if @_;
7545 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
7546 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
7547 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
7548 the value in case a restart is done so we can change it then.
7554 _db_warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_;
7558 } ## end sub ReadLine
7560 =head2 C<RemotePort>
7562 Sets the port that the debugger will try to connect to when starting up.
7563 If the terminal's already been set up, we can't do it, but we remember the
7564 setting in case the user does a restart.
7570 _db_warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
7572 $remoteport = shift if @_;
7574 } ## end sub RemotePort
7578 Checks with the terminal to see if C<Tk> is running, and returns true or
7579 false. Returns false if the current terminal doesn't support C<readline>.
7584 if ( ${ $term->Features }{tkRunning} ) {
7585 return $term->tkRunning(@_);
7589 print $OUT "tkRunning not supported by current ReadLine package.\n";
7592 } ## end sub tkRunning
7596 Sets nonstop mode. If a terminal's already been set up, it's too late; the
7597 debugger remembers the setting in case you restart, though.
7603 _db_warn("Too late to set up NonStop mode, enabled on next 'R'!\n")
7606 $runnonstop = shift if @_;
7608 } ## end sub NonStop
7612 _db_warn("Some flag changes could not take effect until next 'R'!\n")
7615 $^P = parse_DollarCaretP_flags(shift) if @_;
7616 expand_DollarCaretP_flags($^P);
7621 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
7629 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7636 Sets the shell escape command, and generates a printable copy to be used
7643 # If we got an argument, meta-quote it, and add '\b' if it
7644 # ends in a word character.
7646 $sh = quotemeta shift;
7647 $sh .= "\\b" if $sh =~ /\w$/;
7650 # Generate the printable version for the help:
7651 $psh = $sh; # copy it
7652 $psh =~ s/\\b$//; # Take off trailing \b if any
7653 $psh =~ s/\\(.)/$1/g; # De-escape
7654 $psh; # return the printable version
7655 } ## end sub shellBang
7659 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7660 was passed as the argument. (This means you can't override the terminal's
7666 if ( defined $term ) {
7668 # We don't want to show warning backtraces, but we do want die() ones.
7669 local $warnLevel = 0;
7670 local $dieLevel = 1;
7672 # No ornaments if the terminal doesn't support them.
7673 if (not $term->Features->{ornaments}) {
7677 return (eval { $term->ornaments(@_) } || '');
7680 # Use what was passed in if we can't determine it ourselves.
7687 } ## end sub ornaments
7689 =head2 C<recallCommand>
7691 Sets the recall command, and builds a printable version which will appear in
7698 # If there is input, metaquote it. Add '\b' if it ends with a word
7701 $rc = quotemeta shift;
7702 $rc .= "\\b" if $rc =~ /\w$/;
7705 # Build it into a printable version.
7706 $prc = $rc; # Copy it
7707 $prc =~ s/\\b$//; # Remove trailing \b
7708 $prc =~ s/\\(.)/$1/g; # Remove escapes
7709 return $prc; # Return the printable version
7710 } ## end sub recallCommand
7712 =head2 C<LineInfo> - where the line number information goes
7714 Called with no arguments, returns the file or pipe that line info should go to.
7716 Called with an argument (a file or a pipe), it opens that onto the
7717 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7718 file or pipe again to the caller.
7726 # If this is a valid "thing to be opened for output", tack a
7727 # '>' onto the front.
7728 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7730 # If this is a pipe, the stream points to a slave editor.
7731 $slave_editor = ( $stream =~ /^\|/ );
7733 my $new_lineinfo_fh;
7734 # Open it up and unbuffer it.
7735 open ($new_lineinfo_fh , $stream )
7736 or _db_warn("Cannot open '$stream' for write");
7737 $LINEINFO = $new_lineinfo_fh;
7738 $LINEINFO->autoflush(1);
7742 } ## end sub LineInfo
7744 =head1 COMMAND SUPPORT ROUTINES
7746 These subroutines provide functionality for various commands.
7748 =head2 C<list_modules>
7750 For the C<M> command: list modules loaded and their versions.
7751 Essentially just runs through the keys in %INC, picks each package's
7752 C<$VERSION> variable, gets the file name, and formats the information
7757 sub list_modules { # versions
7761 # keys are the "as-loaded" name, values are the fully-qualified path
7762 # to the file itself.
7764 $file = $_; # get the module name
7765 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7766 s,/,::,g; # change '/' to '::'
7767 s/^perl5db$/DB/; # Special case: debugger
7768 # moves to package DB
7769 s/^Term::ReadLine::readline$/readline/; # simplify readline
7771 # If the package has a $VERSION package global (as all good packages
7772 # should!) decode it and save as partial message.
7773 my $pkg_version = do { no strict 'refs'; ${ $_ . '::VERSION' } };
7774 if ( defined $pkg_version ) {
7775 $version{$file} = "$pkg_version from ";
7778 # Finish up the message with the file the package came from.
7779 $version{$file} .= $INC{$file};
7780 } ## end for (keys %INC)
7782 # Hey, dumpit() formats a hash nicely, so why not use it?
7783 dumpit( $OUT, \%version );
7784 } ## end sub list_modules
7788 Sets up the monster string used to format and print the help.
7790 =head3 HELP MESSAGE FORMAT
7792 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
7793 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
7794 easy to parse and portable, but which still allows the help to be a little
7795 nicer than just plain text.
7797 Essentially, you define the command name (usually marked up with C<< B<> >>
7798 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
7799 newline. The descriptive text can also be marked up in the same way. If you
7800 need to continue the descriptive text to another line, start that line with
7801 just tabs and then enter the marked-up text.
7803 If you are modifying the help text, I<be careful>. The help-string parser is
7804 not very sophisticated, and if you don't follow these rules it will mangle the
7805 help beyond hope until you fix the string.
7809 use vars qw($pre580_help);
7810 use vars qw($pre580_summary);
7814 # XXX: make sure there are tabs between the command and explanation,
7815 # or print_help will screw up your formatting if you have
7816 # eeevil ornaments enabled. This is an insane mess.
7819 Help is currently only available for the new 5.8 command set.
7820 No help is available for the old command set.
7821 We assume you know what you're doing if you switch to it.
7824 B<s> [I<expr>] Single step [in I<expr>].
7825 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7826 <B<CR>> Repeat last B<n> or B<s> command.
7827 B<r> Return from current subroutine.
7828 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7829 at the specified position.
7830 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7831 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7832 B<l> I<line> List single I<line>.
7833 B<l> I<subname> List first window of lines from subroutine.
7834 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7835 B<l> List next window of lines.
7836 B<-> List previous window of lines.
7837 B<v> [I<line>] View window around I<line>.
7838 B<.> Return to the executed line.
7839 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7840 I<filename> may be either the full name of the file, or a regular
7841 expression matching the full file name:
7842 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7843 Evals (with saved bodies) are considered to be filenames:
7844 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7845 (in the order of execution).
7846 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7847 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7848 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
7849 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7850 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth).
7851 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
7852 B<b> Sets breakpoint on current line)
7853 B<b> [I<line>] [I<condition>]
7854 Set breakpoint; I<line> defaults to the current execution line;
7855 I<condition> breaks if it evaluates to true, defaults to '1'.
7856 B<b> I<subname> [I<condition>]
7857 Set breakpoint at first line of subroutine.
7858 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7859 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7860 B<b> B<postpone> I<subname> [I<condition>]
7861 Set breakpoint at first line of subroutine after
7863 B<b> B<compile> I<subname>
7864 Stop after the subroutine is compiled.
7865 B<B> [I<line>] Delete the breakpoint for I<line>.
7866 B<B> I<*> Delete all breakpoints.
7867 B<a> [I<line>] I<command>
7868 Set an action to be done before the I<line> is executed;
7869 I<line> defaults to the current execution line.
7870 Sequence is: check for breakpoint/watchpoint, print line
7871 if necessary, do action, prompt user if necessary,
7874 B<A> [I<line>] Delete the action for I<line>.
7875 B<A> I<*> Delete all actions.
7876 B<w> I<expr> Add a global watch-expression.
7878 B<W> I<expr> Delete a global watch-expression.
7879 B<W> I<*> Delete all watch-expressions.
7880 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7881 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7882 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7883 B<x> I<expr> Evals expression in list context, dumps the result.
7884 B<m> I<expr> Evals expression in list context, prints methods callable
7885 on the first element of the result.
7886 B<m> I<class> Prints methods callable via the given class.
7887 B<M> Show versions of loaded modules.
7888 B<i> I<class> Prints nested parents of given class.
7889 B<e> Display current thread id.
7890 B<E> Display all thread ids the current one will be identified: <n>.
7891 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7893 B<<> ? List Perl commands to run before each prompt.
7894 B<<> I<expr> Define Perl command to run before each prompt.
7895 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7896 B<< *> Delete the list of perl commands to run before each prompt.
7897 B<>> ? List Perl commands to run after each prompt.
7898 B<>> I<expr> Define Perl command to run after each prompt.
7899 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7900 B<>>B< *> Delete the list of Perl commands to run after each prompt.
7901 B<{> I<db_command> Define debugger command to run before each prompt.
7902 B<{> ? List debugger commands to run before each prompt.
7903 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7904 B<{ *> Delete the list of debugger commands to run before each prompt.
7905 B<$prc> I<number> Redo a previous command (default previous command).
7906 B<$prc> I<-number> Redo number'th-to-last command.
7907 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7908 See 'B<O> I<recallCommand>' too.
7909 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7914 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7916 See 'B<O> I<shellBang>' too.
7917 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7918 B<save> I<file> Save current debugger session (actual history) to I<file>.
7919 B<rerun> Rerun session to current position.
7920 B<rerun> I<n> Rerun session to numbered command.
7921 B<rerun> I<-n> Rerun session to number'th-to-last command.
7922 B<H> I<-number> Display last number commands (default all).
7923 B<H> I<*> Delete complete history.
7924 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7925 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7926 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well.
7927 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7928 I<command> Execute as a perl statement in current package.
7929 B<R> Pure-man-restart of debugger, some of debugger state
7930 and command-line options may be lost.
7931 Currently the following settings are preserved:
7932 history, breakpoints and actions, debugger B<O>ptions
7933 and the following command-line options: I<-w>, I<-I>, I<-e>.
7935 B<o> [I<opt>] ... Set boolean option to true
7936 B<o> [I<opt>B<?>] Query options
7937 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7938 Set options. Use quotes if spaces in value.
7939 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7940 I<pager> program for output of \"|cmd\";
7941 I<tkRunning> run Tk while prompting (with ReadLine);
7942 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7943 I<inhibit_exit> Allows stepping off the end of the script.
7944 I<ImmediateStop> Debugger should stop as early as possible.
7945 I<RemotePort> Remote hostname:port for remote debugging
7946 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7947 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7948 I<compactDump>, I<veryCompact> change style of array and hash dump;
7949 I<globPrint> whether to print contents of globs;
7950 I<DumpDBFiles> dump arrays holding debugged files;
7951 I<DumpPackages> dump symbol tables of packages;
7952 I<DumpReused> dump contents of \"reused\" addresses;
7953 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7954 I<bareStringify> Do not print the overload-stringified value;
7955 Other options include:
7956 I<PrintRet> affects printing of return value after B<r> command,
7957 I<frame> affects printing messages on subroutine entry/exit.
7958 I<AutoTrace> affects printing messages on possible breaking points.
7959 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7960 I<ornaments> affects screen appearance of the command line.
7961 I<CreateTTY> bits control attempts to create a new TTY on events:
7962 1: on fork() 2: debugger is started inside debugger
7964 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7965 You can put additional initialization options I<TTY>, I<noTTY>,
7966 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7967 B<R> after you set them).
7969 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7970 B<h> Summary of debugger commands.
7971 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7972 B<h h> Long help for debugger commands
7973 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7974 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7975 Set B<\$DB::doccmd> to change viewer.
7977 Type '|h h' for a paged display if this was too hard to read.
7979 "; # Fix balance of vi % matching: }}}}
7981 # note: tabs in the following section are not-so-helpful
7982 $summary = <<"END_SUM";
7983 I<List/search source lines:> I<Control script execution:>
7984 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7985 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7986 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7987 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7988 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7989 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7990 I<Debugger controls:> B<L> List break/watch/actions
7991 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr]
7992 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7993 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7994 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7995 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7996 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7997 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7998 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7999 B<q> or B<^D> Quit B<R> Attempt a restart
8000 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8001 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8002 B<p> I<expr> Print expression (uses script's current package).
8003 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8004 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8005 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
8006 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8007 B<e> Display thread id B<E> Display all thread ids.
8008 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8011 # ')}}; # Fix balance of vi % matching
8013 # and this is really numb...
8016 B<s> [I<expr>] Single step [in I<expr>].
8017 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
8018 B<CR>> Repeat last B<n> or B<s> command.
8019 B<r> Return from current subroutine.
8020 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
8021 at the specified position.
8022 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
8023 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
8024 B<l> I<line> List single I<line>.
8025 B<l> I<subname> List first window of lines from subroutine.
8026 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
8027 B<l> List next window of lines.
8028 B<-> List previous window of lines.
8029 B<w> [I<line>] List window around I<line>.
8030 B<.> Return to the executed line.
8031 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
8032 I<filename> may be either the full name of the file, or a regular
8033 expression matching the full file name:
8034 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
8035 Evals (with saved bodies) are considered to be filenames:
8036 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
8037 (in the order of execution).
8038 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
8039 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
8040 B<L> List all breakpoints and actions.
8041 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
8042 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) .
8043 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
8044 B<b> [I<line>] [I<condition>]
8045 Set breakpoint; I<line> defaults to the current execution line;
8046 I<condition> breaks if it evaluates to true, defaults to '1'.
8047 B<b> I<subname> [I<condition>]
8048 Set breakpoint at first line of subroutine.
8049 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
8050 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
8051 B<b> B<postpone> I<subname> [I<condition>]
8052 Set breakpoint at first line of subroutine after
8054 B<b> B<compile> I<subname>
8055 Stop after the subroutine is compiled.
8056 B<d> [I<line>] Delete the breakpoint for I<line>.
8057 B<D> Delete all breakpoints.
8058 B<a> [I<line>] I<command>
8059 Set an action to be done before the I<line> is executed;
8060 I<line> defaults to the current execution line.
8061 Sequence is: check for breakpoint/watchpoint, print line
8062 if necessary, do action, prompt user if necessary,
8064 B<a> [I<line>] Delete the action for I<line>.
8065 B<A> Delete all actions.
8066 B<W> I<expr> Add a global watch-expression.
8067 B<W> Delete all watch-expressions.
8068 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
8069 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
8070 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
8071 B<x> I<expr> Evals expression in list context, dumps the result.
8072 B<m> I<expr> Evals expression in list context, prints methods callable
8073 on the first element of the result.
8074 B<m> I<class> Prints methods callable via the given class.
8076 B<<> ? List Perl commands to run before each prompt.
8077 B<<> I<expr> Define Perl command to run before each prompt.
8078 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
8079 B<>> ? List Perl commands to run after each prompt.
8080 B<>> I<expr> Define Perl command to run after each prompt.
8081 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
8082 B<{> I<db_command> Define debugger command to run before each prompt.
8083 B<{> ? List debugger commands to run before each prompt.
8084 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
8085 B<$prc> I<number> Redo a previous command (default previous command).
8086 B<$prc> I<-number> Redo number'th-to-last command.
8087 B<$prc> I<pattern> Redo last command that started with I<pattern>.
8088 See 'B<O> I<recallCommand>' too.
8089 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
8094 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
8096 See 'B<O> I<shellBang>' too.
8097 B<source> I<file> Execute I<file> containing debugger commands (may nest).
8098 B<H> I<-number> Display last number commands (default all).
8099 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
8100 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
8101 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
8102 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
8103 I<command> Execute as a perl statement in current package.
8104 B<v> Show versions of loaded modules.
8105 B<R> Pure-man-restart of debugger, some of debugger state
8106 and command-line options may be lost.
8107 Currently the following settings are preserved:
8108 history, breakpoints and actions, debugger B<O>ptions
8109 and the following command-line options: I<-w>, I<-I>, I<-e>.
8111 B<O> [I<opt>] ... Set boolean option to true
8112 B<O> [I<opt>B<?>] Query options
8113 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
8114 Set options. Use quotes if spaces in value.
8115 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
8116 I<pager> program for output of \"|cmd\";
8117 I<tkRunning> run Tk while prompting (with ReadLine);
8118 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
8119 I<inhibit_exit> Allows stepping off the end of the script.
8120 I<ImmediateStop> Debugger should stop as early as possible.
8121 I<RemotePort> Remote hostname:port for remote debugging
8122 The following options affect what happens with B<V>, B<X>, and B<x> commands:
8123 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
8124 I<compactDump>, I<veryCompact> change style of array and hash dump;
8125 I<globPrint> whether to print contents of globs;
8126 I<DumpDBFiles> dump arrays holding debugged files;
8127 I<DumpPackages> dump symbol tables of packages;
8128 I<DumpReused> dump contents of \"reused\" addresses;
8129 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
8130 I<bareStringify> Do not print the overload-stringified value;
8131 Other options include:
8132 I<PrintRet> affects printing of return value after B<r> command,
8133 I<frame> affects printing messages on subroutine entry/exit.
8134 I<AutoTrace> affects printing messages on possible breaking points.
8135 I<maxTraceLen> gives max length of evals/args listed in stack trace.
8136 I<ornaments> affects screen appearance of the command line.
8137 I<CreateTTY> bits control attempts to create a new TTY on events:
8138 1: on fork() 2: debugger is started inside debugger
8140 During startup options are initialized from \$ENV{PERLDB_OPTS}.
8141 You can put additional initialization options I<TTY>, I<noTTY>,
8142 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
8143 B<R> after you set them).
8145 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
8146 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
8147 B<h h> Summary of debugger commands.
8148 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
8149 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
8150 Set B<\$DB::doccmd> to change viewer.
8152 Type '|h' for a paged display if this was too hard to read.
8154 "; # Fix balance of vi % matching: }}}}
8156 # note: tabs in the following section are not-so-helpful
8157 $pre580_summary = <<"END_SUM";
8158 I<List/search source lines:> I<Control script execution:>
8159 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8160 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8161 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
8162 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8163 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8164 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
8165 I<Debugger controls:> B<L> List break/watch/actions
8166 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
8167 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8168 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
8169 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8170 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
8171 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
8172 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8173 B<q> or B<^D> Quit B<R> Attempt a restart
8174 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8175 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8176 B<p> I<expr> Print expression (uses script's current package).
8177 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8178 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8179 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
8180 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8181 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8184 # ')}}; # Fix balance of vi % matching
8186 } ## end sub sethelp
8188 =head2 C<print_help()>
8190 Most of what C<print_help> does is just text formatting. It finds the
8191 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
8192 terminal control characters to simulate them (courtesy of
8193 C<Term::ReadLine::TermCap>).
8198 my $help_str = shift;
8200 # Restore proper alignment destroyed by eeevil I<> and B<>
8201 # ornaments: A pox on both their houses!
8203 # A help command will have everything up to and including
8204 # the first tab sequence padded into a field 16 (or if indented 20)
8205 # wide. If it's wider than that, an extra space will be added.
8207 ^ # only matters at start of line
8208 ( \040{4} | \t )* # some subcommands are indented
8209 ( < ? # so <CR> works
8210 [BI] < [^\t\n] + ) # find an eeevil ornament
8211 ( \t+ ) # original separation, discarded
8212 ( .* ) # this will now start (no earlier) than
8215 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
8216 my $clean = $command;
8217 $clean =~ s/[BI]<([^>]*)>/$1/g;
8219 # replace with this whole string:
8220 ($leadwhite ? " " x 4 : "")
8222 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
8227 $help_str =~ s{ # handle bold ornaments
8228 B < ( [^>] + | > ) >
8230 $Term::ReadLine::TermCap::rl_term_set[2]
8232 . $Term::ReadLine::TermCap::rl_term_set[3]
8235 $help_str =~ s{ # handle italic ornaments
8236 I < ( [^>] + | > ) >
8238 $Term::ReadLine::TermCap::rl_term_set[0]
8240 . $Term::ReadLine::TermCap::rl_term_set[1]
8244 print {$OUT} $help_str;
8247 } ## end sub print_help
8251 This routine does a lot of gyrations to be sure that the pager is C<less>.
8252 It checks for C<less> masquerading as C<more> and records the result in
8253 C<$fixed_less> so we don't have to go through doing the stats again.
8257 use vars qw($fixed_less);
8260 if ($pager =~ /\bless\b/)
8264 elsif ($pager =~ /\bmore\b/)
8266 # Nope, set to more. See what's out there.
8267 my @st_more = stat('/usr/bin/more');
8268 my @st_less = stat('/usr/bin/less');
8270 # is it really less, pretending to be more?
8274 && $st_more[0] == $st_less[0]
8275 && $st_more[1] == $st_less[1]
8285 # We already know if this is set.
8286 return if $fixed_less;
8288 # changes environment!
8289 # 'r' added so we don't do (slow) stats again.
8290 $fixed_less = 1 if _calc_is_less();
8293 } ## end sub fix_less
8295 =head1 DIE AND WARN MANAGEMENT
8299 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
8300 to debug a debugger problem.
8302 It does its best to report the error that occurred, and then forces the
8303 program, debugger, and everything to die.
8309 # No entry/exit messages.
8312 # No return value prints.
8315 # set the abort signal handling to the default (just terminate).
8316 $SIG{'ABRT'} = 'DEFAULT';
8318 # If we enter the signal handler recursively, kill myself with an
8319 # abort signal (so we just terminate).
8320 kill 'ABRT', $$ if $panic++;
8322 # If we can show detailed info, do so.
8323 if ( defined &Carp::longmess ) {
8325 # Don't recursively enter the warn handler, since we're carping.
8326 local $SIG{__WARN__} = '';
8328 # Skip two levels before reporting traceback: we're skipping
8329 # mydie and confess.
8330 local $Carp::CarpLevel = 2; # mydie + confess
8332 # Tell us all about it.
8333 _db_warn( Carp::longmess("Signal @_") );
8336 # No Carp. Tell us about the signal as best we can.
8339 print $DB::OUT "Got signal @_\n";
8344 } ## end sub diesignal
8348 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
8349 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
8355 # No entry/exit trace.
8358 # No return value printing.
8361 # Turn off warn and die handling to prevent recursive entries to this
8363 local $SIG{__WARN__} = '';
8364 local $SIG{__DIE__} = '';
8366 # Load Carp if we can. If $^S is false (current thing being compiled isn't
8367 # done yet), we may not be able to do a require.
8368 eval { require Carp }
8369 if defined $^S; # If error/warning during compilation,
8370 # require may be broken.
8372 # Use the core warn() unless Carp loaded OK.
8374 "\nCannot print stack trace, load with -MCarp option to see stack" ),
8376 unless defined &Carp::longmess;
8378 # Save the current values of $single and $trace, and then turn them off.
8379 my ( $mysingle, $mytrace ) = ( $single, $trace );
8383 # We can call Carp::longmess without its being "debugged" (which we
8384 # don't want - we just want to use it!). Capture this for later.
8385 my $mess = Carp::longmess(@_);
8387 # Restore $single and $trace to their original values.
8388 ( $single, $trace ) = ( $mysingle, $mytrace );
8390 # Use the debugger's own special way of printing warnings to print
8391 # the stack trace message.
8397 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
8398 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
8399 single stepping and tracing during the call to C<Carp::longmess> to avoid
8400 debugging it - we just want to use it.
8402 If C<dieLevel> is zero, we let the program being debugged handle the
8403 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
8404 the debugger takes over all exception handling, printing a backtrace and
8405 displaying the exception via its C<dbwarn()> routine.
8412 local $SIG{__DIE__} = '';
8413 local $SIG{__WARN__} = '';
8414 if ( $dieLevel > 2 ) {
8415 local $SIG{__WARN__} = \&dbwarn;
8416 _db_warn(@_); # Yell no matter what
8419 if ( $dieLevel < 2 ) {
8420 die @_ if $^S; # in eval propagate
8423 # The code used to check $^S to see if compilation of the current thing
8424 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
8425 eval { require Carp };
8428 "\nCannot print stack trace, load with -MCarp option to see stack" )
8429 unless defined &Carp::longmess;
8431 # We do not want to debug this chunk (automatic disabling works
8432 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
8433 # get the stack trace from Carp::longmess (if possible), restore $signal
8434 # and $trace, and then die with the stack trace.
8435 my ( $mysingle, $mytrace ) = ( $single, $trace );
8441 package Carp; # Do not include us in the list
8442 eval { $mess = Carp::longmess(@_); };
8444 ( $single, $trace ) = ( $mysingle, $mytrace );
8448 =head2 C<warnlevel()>
8450 Set the C<$DB::warnLevel> variable that stores the value of the
8451 C<warnLevel> option. Calling C<warnLevel()> with a positive value
8452 results in the debugger taking over all warning handlers. Setting
8453 C<warnLevel> to zero leaves any warning handlers set up by the program
8454 being debugged in place.
8460 my $prevwarn = $SIG{__WARN__} unless $warnLevel;
8463 $SIG{__WARN__} = \&DB::dbwarn;
8466 $SIG{__WARN__} = $prevwarn;
8468 undef $SIG{__WARN__};
8472 } ## end sub warnLevel
8476 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
8477 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
8478 zero lets you use your own C<die()> handler.
8485 my $prevdie = $SIG{__DIE__} unless $dieLevel;
8489 # Always set it to dbdie() for non-zero values.
8490 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
8492 # No longer exists, so don't try to use it.
8493 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
8495 # If we've finished initialization, mention that stack dumps
8496 # are enabled, If dieLevel is 1, we won't stack dump if we die
8498 print $OUT "Stack dump during die enabled",
8499 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
8502 # XXX This is probably obsolete, given that diehard() is gone.
8503 print $OUT "Dump printed too.\n" if $dieLevel > 2;
8504 } ## end if ($dieLevel)
8506 # Put the old one back if there was one.
8508 $SIG{__DIE__} = $prevdie;
8509 print $OUT "Default die handler restored.\n";
8511 undef $SIG{__DIE__};
8512 print $OUT "Die handler removed.\n";
8516 } ## end sub dieLevel
8518 =head2 C<signalLevel>
8520 Number three in a series: set C<signalLevel> to zero to keep your own
8521 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
8522 takes over and handles them with C<DB::diesignal()>.
8528 my $prevsegv = $SIG{SEGV} unless $signalLevel;
8529 my $prevbus = $SIG{BUS} unless $signalLevel;
8530 $signalLevel = shift;
8532 $SIG{SEGV} = \&DB::diesignal;
8533 $SIG{BUS} = \&DB::diesignal;
8536 $SIG{SEGV} = $prevsegv;
8537 $SIG{BUS} = $prevbus;
8541 } ## end sub signalLevel
8543 =head1 SUBROUTINE DECODING SUPPORT
8545 These subroutines are used during the C<x> and C<X> commands to try to
8546 produce as much information as possible about a code reference. They use
8547 L<Devel::Peek> to try to find the glob in which this code reference lives
8548 (if it does) - this allows us to actually code references which correspond
8549 to named subroutines (including those aliased via glob assignment).
8551 =head2 C<CvGV_name()>
8553 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
8554 via that routine. If this fails, return the reference again (when the
8555 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
8561 my $name = CvGV_name_or_bust($in);
8562 defined $name ? $name : $in;
8565 =head2 C<CvGV_name_or_bust> I<coderef>
8567 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
8568 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
8569 find a glob for this ref.
8571 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
8575 use vars qw($skipCvGV);
8577 sub CvGV_name_or_bust {
8579 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
8580 return unless ref $in;
8581 $in = \&$in; # Hard reference...
8582 eval { require Devel::Peek; 1 } or return;
8583 my $gv = Devel::Peek::CvGV($in) or return;
8584 *$gv{PACKAGE} . '::' . *$gv{NAME};
8585 } ## end sub CvGV_name_or_bust
8589 A utility routine used in various places; finds the file where a subroutine
8590 was defined, and returns that filename and a line-number range.
8592 Tries to use C<@sub> first; if it can't find it there, it tries building a
8593 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
8594 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
8595 this way, it brute-force searches C<%sub>, checking for identical references.
8599 sub _find_sub_helper {
8602 return unless defined &$subr;
8603 my $name = CvGV_name_or_bust($subr);
8605 $data = $sub{$name} if defined $name;
8606 return $data if defined $data;
8609 $subr = \&$subr; # Hard reference
8612 $s = $_, last if $subr eq \&$_;
8627 return ( $sub{$subr} || _find_sub_helper($subr) );
8628 } ## end sub find_sub
8632 A subroutine that uses the utility function C<methods_via> to find all the
8633 methods in the class corresponding to the current reference and in
8642 # Figure out the class - either this is the class or it's a reference
8643 # to something blessed into that class.
8645 $class = ref $class if ref $class;
8649 # Show the methods that this class has.
8650 methods_via( $class, '', 1 );
8652 # Show the methods that UNIVERSAL has.
8653 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
8654 } ## end sub methods
8656 =head2 C<methods_via($class, $prefix, $crawl_upward)>
8658 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
8659 all the parent class methods. C<$class> is the name of the next class to
8660 try; C<$prefix> is the message prefix, which gets built up as we go up the
8661 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
8662 higher in the C<@ISA> tree, 0 if we should stop.
8668 # If we've processed this class already, just quit.
8670 return if $seen{$class}++;
8672 # This is a package that is contributing the methods we're about to print.
8674 my $prepend = $prefix ? "via $prefix: " : '';
8677 # Extract from all the symbols in this class.
8678 my $class_ref = do { no strict "refs"; \%{$class . '::'} };
8679 while (my ($name, $glob) = each %$class_ref) {
8680 # references directly in the symbol table are Proxy Constant
8681 # Subroutines, and are by their very nature defined
8682 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8683 # to a subroutine reference, which can be tested by defined.
8684 # $glob might also be the value -1 (from sub foo;)
8685 # or (say) '$$' (from sub foo ($$);)
8686 # \$glob will be SCALAR in both cases.
8687 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8688 && !$seen{$name}++) {
8689 push @to_print, "$prepend$name\n";
8696 print $DB::OUT $_ foreach sort @to_print;
8699 # If the $crawl_upward argument is false, just quit here.
8700 return unless shift;
8702 # $crawl_upward true: keep going up the tree.
8703 # Find all the classes this one is a subclass of.
8704 my $class_ISA_ref = do { no strict "refs"; \@{"${class}::ISA"} };
8705 for my $name ( @$class_ISA_ref ) {
8707 # Set up the new prefix.
8708 $prepend = $prefix ? $prefix . " -> $name" : $name;
8710 # Crawl up the tree and keep trying to crawl up.
8711 methods_via( $name, $prepend, 1 );
8713 } ## end sub methods_via
8715 =head2 C<setman> - figure out which command to use to show documentation
8717 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8722 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|NetWare)\z/s
8723 ? "man" # O Happy Day!
8724 : "perldoc"; # Alas, poor unfortunates
8727 =head2 C<runman> - run the appropriate command to show documentation
8729 Accepts a man page name; runs the appropriate command to display it (set up
8730 during debugger initialization). Uses C<_db_system()> to avoid mucking up the
8731 program's STDIN and STDOUT.
8735 my %_is_in_pods = (map { $_ => 1 }
8872 _db_system("$doccmd $doccmd");
8876 # this way user can override, like with $doccmd="man -Mwhatever"
8877 # or even just "man " to disable the path check.
8878 if ( $doccmd ne 'man' ) {
8879 _db_system("$doccmd $page");
8883 $page = 'perl' if lc($page) eq 'help';
8886 my $man1dir = $Config::Config{'man1dir'};
8887 my $man3dir = $Config::Config{'man3dir'};
8888 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8890 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8891 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8892 chop $manpath if $manpath;
8894 # harmless if missing, I figure
8895 my $oldpath = $ENV{MANPATH};
8896 $ENV{MANPATH} = $manpath if $manpath;
8897 my $nopathopt = $^O =~ /dunno what goes here/;
8902 # I just *know* there are men without -M
8903 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8908 unless ( $page =~ /^perl\w/ ) {
8909 # do it this way because its easier to slurp in to keep up to date - clunky though.
8910 if (exists($_is_in_pods{$page})) {
8911 CORE::system( $doccmd,
8912 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8916 } ## end if (CORE::system($doccmd...
8917 if ( defined $oldpath ) {
8918 $ENV{MANPATH} = $manpath;
8921 delete $ENV{MANPATH};
8925 #use Carp; # This did break, left for debugging
8927 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
8929 Because of the way the debugger interface to the Perl core is designed, any
8930 debugger package globals that C<DB::sub()> requires have to be defined before
8931 any subroutines can be called. These are defined in the second C<BEGIN> block.
8933 This block sets things up so that (basically) the world is sane
8934 before the debugger starts executing. We set up various variables that the
8935 debugger has to have set up before the Perl core starts running:
8941 The debugger's own filehandles (copies of STD and STDOUT for now).
8945 Characters for shell escapes, the recall command, and the history command.
8949 The maximum recursion depth.
8953 The size of a C<w> command's window.
8957 The before-this-line context to be printed in a C<v> (view a window around this line) command.
8961 The fact that we're not in a sub at all right now.
8965 The default SIGINT handler for the debugger.
8969 The appropriate value of the flag in C<$^D> that says the debugger is running
8973 The current debugger recursion level
8977 The list of postponed items and the C<$single> stack (XXX define this)
8981 That we want no return values and no subroutine entry/exit trace.
8987 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
8989 use vars qw($db_stop);
8991 BEGIN { # This does not compile, alas. (XXX eh?)
8992 $IN = \*STDIN; # For bugs before DB::OUT has been opened
8993 $OUT = \*STDERR; # For errors before DB::OUT has been opened
8995 # Define characters used by command parsing.
8996 $sh = '!'; # Shell escape (does not work)
8997 $rc = ','; # Recall command (does not work)
8998 @hist = ('?'); # Show history (does not work)
8999 @truehist = (); # Can be saved for replay (per session)
9001 # This defines the point at which you get the 'deep recursion'
9002 # warning. It MUST be defined or the debugger will not load.
9005 # Number of lines around the current one that are shown in the
9009 # How much before-the-current-line context the 'v' command should
9010 # use in calculating the start of the window it will display.
9013 # We're not in any sub yet, but we need this to be a defined value.
9016 # Set up the debugger's interrupt handler. It simply sets a flag
9017 # ($signal) that DB::DB() will check before each command is executed.
9018 $SIG{INT} = \&DB::catch;
9020 # The following lines supposedly, if uncommented, allow the debugger to
9021 # debug itself. Perhaps we can try that someday.
9022 # This may be enabled to debug debugger:
9023 #$warnLevel = 1 unless defined $warnLevel;
9024 #$dieLevel = 1 unless defined $dieLevel;
9025 #$signalLevel = 1 unless defined $signalLevel;
9027 # This is the flag that says "a debugger is running, please call
9028 # DB::DB and DB::sub". We will turn it on forcibly before we try to
9029 # execute anything in the user's context, because we always want to
9031 $db_stop = 0; # Compiler warning ...
9032 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
9034 # This variable records how many levels we're nested in debugging. Used
9035 # Used in the debugger prompt, and in determining whether it's all over or
9037 $level = 0; # Level of recursive debugging
9039 # "Triggers bug (?) in perl if we postpone this until runtime."
9040 # XXX No details on this yet, or whether we should fix the bug instead
9041 # of work around it. Stay tuned.
9044 # Used to track the current stack depth using the auto-stacked-variable
9046 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
9048 # Don't print return values on exiting a subroutine.
9051 # No extry/exit tracing.
9056 BEGIN { $^W = $ini_warn; } # Switch warnings back
9058 =head1 READLINE SUPPORT - COMPLETION FUNCTION
9062 C<readline> support - adds command completion to basic C<readline>.
9064 Returns a list of possible completions to C<readline> when invoked. C<readline>
9065 will print the longest common substring following the text already entered.
9067 If there is only a single possible completion, C<readline> will use it in full.
9069 This code uses C<map> and C<grep> heavily to create lists of possible
9070 completion. Think LISP in this section.
9076 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
9077 # $text is the text to be completed.
9078 # $line is the incoming line typed by the user.
9079 # $start is the start of the text to be completed in the incoming line.
9080 my ( $text, $line, $start ) = @_;
9082 # Save the initial text.
9083 # The search pattern is current package, ::, extract the next qualifier
9084 # Prefix and pack are set to undef.
9085 my ( $itext, $search, $prefix, $pack ) =
9086 ( $text, "^\Q${package}::\E([^:]+)\$" );
9088 =head3 C<b postpone|compile>
9094 Find all the subroutines that might match in this package
9098 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
9102 Include all the rest of the subs that are known
9106 C<grep> out the ones that match the text we have so far
9110 Return this as the list of possible completions
9116 return sort grep /^\Q$text/, ( keys %sub ),
9117 qw(postpone load compile), # subroutines
9118 ( map { /$search/ ? ($1) : () } keys %sub )
9119 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
9123 Get all the possible files from C<@INC> as it currently stands and
9124 select the ones that match the text so far.
9128 return sort grep /^\Q$text/, values %INC # files
9129 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
9131 =head3 C<V> (list variable) and C<m> (list modules)
9133 There are two entry points for these commands:
9135 =head4 Unqualified package names
9137 Get the top-level packages and grab everything that matches the text
9138 so far. For each match, recursively complete the partial packages to
9139 get all possible matching packages. Return this sorted list.
9143 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9144 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
9145 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
9147 =head4 Qualified package names
9149 Take a partially-qualified package and find all subpackages for it
9150 by getting all the subpackages for the package so far, matching all
9151 the subpackages against the text, and discarding all of them which
9152 start with 'main::'. Return this list.
9156 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9157 grep !/^main::/, grep /^\Q$text/,
9158 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () }
9159 do { no strict 'refs'; keys %{ $prefix . '::' } }
9160 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
9161 and $text =~ /^(.*[^:])::?(\w*)$/
9164 =head3 C<f> - switch files
9166 Here, we want to get a fully-qualified filename for the C<f> command.
9171 =item 1. The original source file itself
9173 =item 2. A file from C<@INC>
9175 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
9181 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
9182 # We might possibly want to switch to an eval (which has a "filename"
9183 # like '(eval 9)'), so we may need to clean up the completion text
9184 # before proceeding.
9185 $prefix = length($1) - length($text);
9190 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
9191 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
9192 out of C<%main::>, add the initial source file, and extract the ones that
9193 match the completion text so far.
9198 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
9200 } ## end if ($line =~ /^\|*f\s+(.*)/)
9202 =head3 Subroutine name completion
9204 We look through all of the defined subs (the keys of C<%sub>) and
9205 return both all the possible matches to the subroutine name plus
9206 all the matches qualified to the current package.
9210 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
9211 $text = substr $text, 1;
9213 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
9215 map { /$search/ ? ($1) : () }
9218 } ## end if ((substr $text, 0, ...
9220 =head3 Scalar, array, and hash completion: partially qualified package
9222 Much like the above, except we have to do a little more cleanup:
9226 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
9234 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
9238 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
9244 Figure out the prefix vs. what needs completing.
9248 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
9255 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
9261 map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
9269 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.
9273 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9274 return db_complete( $out[0], $line, $start );
9277 # Return the list of possibles.
9280 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
9286 =head3 Symbol completion: current package or package C<main>.
9290 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
9297 If it's C<main>, delete main to just get C<::> leading.
9301 $pack = ( $package eq 'main' ? '' : $package ) . '::';
9307 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
9311 $prefix = substr $text, 0, 1;
9312 $text = substr $text, 1;
9320 We look for the lexical scope above DB::DB and auto-complete lexical variables
9321 if PadWalker could be loaded.
9325 if (not $text =~ /::/ and eval { require PadWalker } ) {
9328 my @info = caller($level);
9332 last if $info[3] eq 'DB::DB';
9335 my $lexicals = PadWalker::peek_my($level);
9336 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
9344 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
9348 push @out, map "$prefix$_", grep /^\Q$text/,
9349 ( grep /^_?[a-zA-Z]/, keys %$pack ),
9350 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
9354 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
9360 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9361 return db_complete( $out[0], $line, $start );
9364 # Return the list of possibles.
9366 } ## end if ($text =~ /^[\$@%]/)
9370 We use C<option_val()> to look up the current value of the option. If there's
9371 only a single value, we complete the command in such a way that it is a
9372 complete command for setting the option in question. If there are multiple
9373 possible values, we generate a command consisting of the option plus a trailing
9374 question mark, which, if executed, will list the current value of the option.
9378 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
9379 { # Options after space
9380 # We look for the text to be matched in the list of possible options,
9381 # and fetch the current value.
9382 my @out = grep /^\Q$text/, @options;
9383 my $val = option_val( $out[0], undef );
9385 # Set up a 'query option's value' command.
9387 if ( not defined $val or $val =~ /[\n\r]/ ) {
9389 # There's really nothing else we can do.
9392 # We have a value. Create a proper option-setting command.
9393 elsif ( $val =~ /\s/ ) {
9395 # XXX This may be an extraneous variable.
9398 # We'll want to quote the string (because of the embedded
9399 # whtespace), but we want to make sure we don't end up with
9400 # mismatched quote characters. We try several possibilities.
9401 foreach my $l ( split //, qq/\"\'\#\|/ ) {
9403 # If we didn't find this quote character in the value,
9404 # quote it using this quote character.
9405 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
9407 } ## end elsif ($val =~ /\s/)
9409 # Don't need any quotes.
9414 # If there were multiple possible values, return '? ', which
9415 # makes the command into a query command. If there was just one,
9416 # have readline append that.
9417 $rl_attribs->{completer_terminator_character} =
9418 ( @out == 1 ? $out : '? ' );
9420 # Return list of possibilities.
9422 } ## end if ((substr $line, 0, ...
9424 =head3 Filename completion
9426 For entering filenames. We simply call C<readline>'s C<filename_list()>
9427 method with the completion text to get the possible completions.
9431 return $term->filename_list($text); # filenames
9433 } ## end sub db_complete
9435 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
9437 Functions that possibly ought to be somewhere else.
9447 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n";
9452 If we have $ini_pids, save it in the environment; else remove it from the
9453 environment. Used by the C<R> (restart) command.
9458 if ( defined($ini_pids) ) {
9459 $ENV{PERLDB_PIDS} = $ini_pids;
9462 delete( $ENV{PERLDB_PIDS} );
9464 } ## end sub clean_ENV
9466 # PERLDBf_... flag names from perl.h
9467 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
9470 %DollarCaretP_flags = (
9471 PERLDBf_SUB => 0x01, # Debug sub enter/exit
9472 PERLDBf_LINE => 0x02, # Keep line #
9473 PERLDBf_NOOPT => 0x04, # Switch off optimizations
9474 PERLDBf_INTER => 0x08, # Preserve more data
9475 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
9476 PERLDBf_SINGLE => 0x20, # Start with single-step on
9477 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
9478 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
9479 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
9480 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
9481 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
9482 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
9484 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
9485 # doesn't need to set it. It's provided for the benefit of profilers and
9486 # other code analysers.
9488 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
9491 sub parse_DollarCaretP_flags {
9496 foreach my $f ( split /\s*\|\s*/, $flags ) {
9498 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
9501 elsif ( $f =~ /^(\d+)$/ ) {
9504 elsif ( $f =~ /^DEFAULT$/i ) {
9505 $value = $DollarCaretP_flags{PERLDB_ALL};
9508 $f =~ /^(?:PERLDBf_)?(.*)$/i;
9509 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
9510 unless ( defined $value ) {
9512 "Unrecognized \$^P flag '$f'!\n",
9513 "Acceptable flags are: "
9514 . join( ', ', sort keys %DollarCaretP_flags ),
9515 ", and hexadecimal and decimal numbers.\n"
9525 sub expand_DollarCaretP_flags {
9526 my $DollarCaretP = shift;
9529 my $n = ( 1 << $_ );
9530 ( $DollarCaretP & $n )
9531 ? ( $DollarCaretP_flags_r{$n}
9532 || sprintf( '0x%x', $n ) )
9536 return @bits ? join( '|', @bits ) : 0;
9543 Rerun the current session to:
9545 rerun current position
9547 rerun 4 command number 4
9549 rerun -4 current command minus 4 (go back 4 steps)
9551 Whether this always makes sense, in the current context is unknowable, and is
9552 in part left as a useful exercise for the reader. This sub returns the
9553 appropriate arguments to rerun the current session.
9560 pop(@truehist); # strim
9561 unless (defined $truehist[$i]) {
9562 print "Unable to return to non-existent command: $i\n";
9564 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
9565 my @temp = @truehist; # store
9566 push(@DB::typeahead, @truehist); # saved
9567 @truehist = @hist = (); # flush
9568 @args = restart(); # setup
9569 get_list("PERLDB_HIST"); # clean
9570 set_list("PERLDB_HIST", @temp); # reset
9577 Restarting the debugger is a complex operation that occurs in several phases.
9578 First, we try to reconstruct the command line that was used to invoke Perl
9584 # I may not be able to resurrect you, but here goes ...
9586 "Warning: some settings and command-line options may be lost!\n";
9587 my ( @script, @flags, $cl );
9589 # If warn was on before, turn it on again.
9590 push @flags, '-w' if $ini_warn;
9592 # Rebuild the -I flags that were on the initial
9595 push @flags, '-I', $_;
9598 # Turn on taint if it was on before.
9599 push @flags, '-T' if ${^TAINT};
9601 # Arrange for setting the old INC:
9602 # Save the current @init_INC in the environment.
9603 set_list( "PERLDB_INC", @ini_INC );
9605 # If this was a perl one-liner, go to the "file"
9606 # corresponding to the one-liner read all the lines
9607 # out of it (except for the first one, which is going
9608 # to be added back on again when 'perl -d' runs: that's
9609 # the 'require perl5db.pl;' line), and add them back on
9610 # to the command line to be executed.
9612 my $lines = *{$main::{'_<-e'}}{ARRAY};
9613 for ( 1 .. $#$lines ) { # The first line is PERL5DB
9614 chomp( $cl = $lines->[$_] );
9615 push @script, '-e', $cl;
9617 } ## end if ($0 eq '-e')
9619 # Otherwise we just reuse the original name we had
9627 After the command line has been reconstructed, the next step is to save
9628 the debugger's status in environment variables. The C<DB::set_list> routine
9629 is used to save aggregate variables (both hashes and arrays); scalars are
9630 just popped into environment variables directly.
9634 # If the terminal supported history, grab it and
9635 # save that in the environment.
9636 set_list( "PERLDB_HIST",
9637 $term->Features->{getHistory}
9641 # Find all the files that were visited during this
9642 # session (i.e., the debugger had magic hashes
9643 # corresponding to them) and stick them in the environment.
9644 my @had_breakpoints = keys %had_breakpoints;
9645 set_list( "PERLDB_VISITED", @had_breakpoints );
9647 # Save the debugger options we chose.
9648 set_list( "PERLDB_OPT", %option );
9649 # set_list( "PERLDB_OPT", options2remember() );
9651 # Save the break-on-loads.
9652 set_list( "PERLDB_ON_LOAD", %break_on_load );
9656 The most complex part of this is the saving of all of the breakpoints. They
9657 can live in an awful lot of places, and we have to go through all of them,
9658 find the breakpoints, and then save them in the appropriate environment
9659 variable via C<DB::set_list>.
9663 # Go through all the breakpoints and make sure they're
9666 for ( 0 .. $#had_breakpoints ) {
9668 # We were in this file.
9669 my $file = $had_breakpoints[$_];
9671 # Grab that file's magic line hash.
9672 *dbline = $main::{ '_<' . $file };
9674 # Skip out if it doesn't exist, or if the breakpoint
9675 # is in a postponed file (we'll do postponed ones
9677 next unless %dbline or $postponed_file{$file};
9679 # In an eval. This is a little harder, so we'll
9680 # do more processing on that below.
9681 ( push @hard, $file ), next
9682 if $file =~ /^\(\w*eval/;
9684 # XXX I have no idea what this is doing. Yet.
9686 @add = %{ $postponed_file{$file} }
9687 if $postponed_file{$file};
9689 # Save the list of all the breakpoints for this file.
9690 set_list( "PERLDB_FILE_$_", %dbline, @add );
9692 # Serialize the extra data %breakpoints_data hash.
9694 set_list( "PERLDB_FILE_ENABLED_$_",
9695 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 }
9696 sort { $a <=> $b } keys(%dbline)
9698 } ## end for (0 .. $#had_breakpoints)
9700 # The breakpoint was inside an eval. This is a little
9701 # more difficult. XXX and I don't understand it.
9703 # Get over to the eval in question.
9704 *dbline = $main::{ '_<' . $_ };
9705 my ( $quoted, $sub, %subs, $line ) = quotemeta $_;
9706 for $sub ( keys %sub ) {
9707 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
9708 $subs{$sub} = [ $1, $2 ];
9712 "No subroutines in $_, ignoring breakpoints.\n";
9715 LINES: for $line ( keys %dbline ) {
9717 # One breakpoint per sub only:
9718 my ( $offset, $sub, $found );
9719 SUBS: for $sub ( keys %subs ) {
9722 $line # Not after the subroutine
9724 not defined $offset # Not caught
9730 $offset = $line - $subs{$sub}->[0];
9731 $offset = "+$offset", last SUBS
9733 } ## end if ($subs{$sub}->[1] >=...
9734 } ## end for $sub (keys %subs)
9735 if ( defined $offset ) {
9736 $postponed{$found} =
9737 "break $offset if $dbline{$line}";
9741 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
9743 } ## end for $line (keys %dbline)
9744 } ## end for (@hard)
9746 # Save the other things that don't need to be
9748 set_list( "PERLDB_POSTPONE", %postponed );
9749 set_list( "PERLDB_PRETYPE", @$pretype );
9750 set_list( "PERLDB_PRE", @$pre );
9751 set_list( "PERLDB_POST", @$post );
9752 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9754 # We are officially restarting.
9755 $ENV{PERLDB_RESTART} = 1;
9757 # We are junking all child debuggers.
9758 delete $ENV{PERLDB_PIDS}; # Restore ini state
9760 # Set this back to the initial pid.
9761 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9765 After all the debugger status has been saved, we take the command we built up
9766 and then return it, so we can C<exec()> it. The debugger will spot the
9767 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9768 from the environment.
9772 # And run Perl again. Add the "-d" flag, all the
9773 # flags we built up, the script (whether a one-liner
9774 # or a file), add on the -emacs flag for a slave editor,
9775 # and then the old arguments.
9777 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9783 =head1 END PROCESSING - THE C<END> BLOCK
9785 Come here at the very end of processing. We want to go into a
9786 loop where we allow the user to enter commands and interact with the
9787 debugger, but we don't want anything else to execute.
9789 First we set the C<$finished> variable, so that some commands that
9790 shouldn't be run after the end of program quit working.
9792 We then figure out whether we're truly done (as in the user entered a C<q>
9793 command, or we finished execution while running nonstop). If we aren't,
9794 we set C<$single> to 1 (causing the debugger to get control again).
9796 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9797 message and returns control to the debugger. Repeat.
9799 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9800 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9801 break, run to completion.).
9806 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9807 $fall_off_end = 1 unless $inhibit_exit;
9809 # Do not stop in at_exit() and destructors on exit:
9810 if ($fall_off_end or $runnonstop) {
9814 DB::fake::at_exit();
9818 =head1 PRE-5.8 COMMANDS
9820 Some of the commands changed function quite a bit in the 5.8 command
9821 realignment, so much so that the old code had to be replaced completely.
9822 Because we wanted to retain the option of being able to go back to the
9823 former command set, we moved the old code off to this section.
9825 There's an awful lot of duplicated code here. We've duplicated the
9826 comments to keep things clear.
9830 Does nothing. Used to I<turn off> commands.
9834 sub cmd_pre580_null {
9839 =head2 Old C<a> command.
9841 This version added actions if you supplied them, and deleted them
9850 # Argument supplied. Add the action.
9851 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9853 # If the line isn't there, use the current line.
9854 my $i = $1 || $line;
9857 # If there is an action ...
9860 # ... but the line isn't breakable, skip it.
9861 if ( $dbline[$i] == 0 ) {
9862 print $OUT "Line $i may not have an action.\n";
9866 # ... and the line is breakable:
9867 # Mark that there's an action in this file.
9868 $had_breakpoints{$filename} |= 2;
9870 # Delete any current action.
9871 $dbline{$i} =~ s/\0[^\0]*//;
9873 # Add the new action, continuing the line as needed.
9874 $dbline{$i} .= "\0" . action($j);
9876 } ## end if (length $j)
9878 # No action supplied.
9881 # Delete the action.
9882 $dbline{$i} =~ s/\0[^\0]*//;
9884 # Mark as having no break or action if nothing's left.
9885 delete $dbline{$i} if $dbline{$i} eq '';
9887 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9888 } ## end sub cmd_pre580_a
9890 =head2 Old C<b> command
9902 if ( $cmd =~ /^load\b\s*(.*)/ ) {
9908 # b compile|postpone <some sub> [<condition>]
9909 # The interpreter actually traps this one for us; we just put the
9910 # necessary condition in the %postponed hash.
9911 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
9913 # Capture the condition if there is one. Make it true if none.
9914 my $cond = length $3 ? $3 : '1';
9916 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
9917 # if it was 'compile'.
9918 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
9920 # De-Perl4-ify the name - ' separators to ::.
9921 $subname =~ s/\'/::/g;
9923 # Qualify it into the current package unless it's already qualified.
9924 $subname = "${package}::" . $subname
9925 unless $subname =~ /::/;
9927 # Add main if it starts with ::.
9928 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
9930 # Save the break type for this sub.
9931 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
9932 } ## end elsif ($cmd =~ ...
9934 # b <sub name> [<condition>]
9935 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
9937 my $cond = length $2 ? $2 : '1';
9938 cmd_b_sub( $subname, $cond );
9940 # b <line> [<condition>].
9941 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9942 my $i = $1 || $dbline;
9943 my $cond = length $2 ? $2 : '1';
9944 cmd_b_line( $i, $cond );
9946 } ## end sub cmd_pre580_b
9948 =head2 Old C<D> command.
9950 Delete all breakpoints unconditionally.
9957 if ( $cmd =~ /^\s*$/ ) {
9958 print $OUT "Deleting all breakpoints...\n";
9960 # %had_breakpoints lists every file that had at least one
9963 for $file ( keys %had_breakpoints ) {
9965 # Switch to the desired file temporarily.
9966 local *dbline = $main::{ '_<' . $file };
9971 # For all lines in this file ...
9972 for my $i (1 .. $max) {
9974 # If there's a breakpoint or action on this line ...
9975 if ( defined $dbline{$i} ) {
9977 # ... remove the breakpoint.
9978 $dbline{$i} =~ s/^[^\0]+//;
9979 if ( $dbline{$i} =~ s/^\0?$// ) {
9981 # Remove the entry altogether if no action is there.
9984 } ## end if (defined $dbline{$i...
9985 } ## end for my $i (1 .. $max)
9987 # If, after we turn off the "there were breakpoints in this file"
9988 # bit, the entry in %had_breakpoints for this file is zero,
9989 # we should remove this file from the hash.
9990 if ( not $had_breakpoints{$file} &= ~1 ) {
9991 delete $had_breakpoints{$file};
9993 } ## end for $file (keys %had_breakpoints)
9995 # Kill off all the other breakpoints that are waiting for files that
9996 # haven't been loaded yet.
9998 undef %postponed_file;
9999 undef %break_on_load;
10000 } ## end if ($cmd =~ /^\s*$/)
10001 } ## end sub cmd_pre580_D
10003 =head2 Old C<h> command
10005 Print help. Defaults to printing the long-form help; the 5.8 version
10006 prints the summary by default.
10014 # Print the *right* help, long format.
10015 if ( $cmd =~ /^\s*$/ ) {
10016 print_help($pre580_help);
10019 # 'h h' - explicitly-requested summary.
10020 elsif ( $cmd =~ /^h\s*/ ) {
10021 print_help($pre580_summary);
10024 # Find and print a command's help.
10025 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
10026 my $asked = $1; # for proper errmsg
10027 my $qasked = quotemeta($asked); # for searching
10028 # XXX: finds CR but not <CR>
10032 (?:[IB]<) # Optional markup
10033 $qasked # The command name
10040 ( # The command help:
10042 (?:[IB]<) # Optional markup
10043 $qasked # The command name
10044 ([\s\S]*?) # Lines starting with tabs
10048 ) # Line not starting with space
10049 # (Next command's help)
10053 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
10057 print_help("B<$asked> is not a debugger command.\n");
10059 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
10060 } ## end sub cmd_pre580_h
10062 =head2 Old C<W> command
10064 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
10072 # Delete all watch expressions.
10073 if ( $cmd =~ /^$/ ) {
10075 # No watching is going on.
10078 # Kill all the watch expressions and values.
10079 @to_watch = @old_watch = ();
10082 # Add a watch expression.
10083 elsif ( $cmd =~ /^(.*)/s ) {
10085 # add it to the list to be watched.
10086 push @to_watch, $1;
10088 # Get the current value of the expression.
10089 # Doesn't handle expressions returning list values!
10091 my ($val) = DB::eval();
10092 $val = ( defined $val ) ? "'$val'" : 'undef';
10095 push @old_watch, $val;
10097 # We're watching stuff.
10100 } ## end elsif ($cmd =~ /^(.*)/s)
10101 } ## end sub cmd_pre580_W
10103 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
10105 The debugger used to have a bunch of nearly-identical code to handle
10106 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
10107 C<cmd_prepost> unify all this into one set of code to handle the
10108 appropriate actions.
10110 =head2 C<cmd_pre590_prepost>
10112 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
10113 do something destructive. In pre 5.8 debuggers, the default action was to
10114 delete all the actions.
10118 sub cmd_pre590_prepost {
10120 my $line = shift || '*';
10121 my $dbline = shift;
10123 return cmd_prepost( $cmd, $line, $dbline );
10124 } ## end sub cmd_pre590_prepost
10126 =head2 C<cmd_prepost>
10128 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
10129 Since the lists of actions are all held in arrays that are pointed to by
10130 references anyway, all we have to do is pick the right array reference and
10131 then use generic code to all, delete, or list actions.
10138 # No action supplied defaults to 'list'.
10139 my $line = shift || '?';
10141 # Figure out what to put in the prompt.
10144 # Make sure we have some array or another to address later.
10145 # This means that if ssome reason the tests fail, we won't be
10146 # trying to stash actions or delete them from the wrong place.
10149 # < - Perl code to run before prompt.
10150 if ( $cmd =~ /^\</o ) {
10151 $which = 'pre-perl';
10155 # > - Perl code to run after prompt.
10156 elsif ( $cmd =~ /^\>/o ) {
10157 $which = 'post-perl';
10161 # { - first check for properly-balanced braces.
10162 elsif ( $cmd =~ /^\{/o ) {
10163 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
10165 "$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n";
10168 # Properly balanced. Pre-prompt debugger actions.
10170 $which = 'pre-debugger';
10173 } ## end elsif ( $cmd =~ /^\{/o )
10175 # Did we find something that makes sense?
10177 print $OUT "Confused by command: $cmd\n";
10184 if ( $line =~ /^\s*\?\s*$/o ) {
10187 # Nothing there. Complain.
10188 print $OUT "No $which actions.\n";
10192 # List the actions in the selected list.
10193 print $OUT "$which commands:\n";
10194 foreach my $action (@$aref) {
10195 print $OUT "\t$cmd -- $action\n";
10198 } ## end if ( $line =~ /^\s*\?\s*$/o)
10200 # Might be a delete.
10202 if ( length($cmd) == 1 ) {
10203 if ( $line =~ /^\s*\*\s*$/o ) {
10205 # It's a delete. Get rid of the old actions in the
10208 print $OUT "All $cmd actions cleared.\n";
10212 # Replace all the actions. (This is a <, >, or {).
10213 @$aref = action($line);
10215 } ## end if ( length($cmd) == 1)
10216 elsif ( length($cmd) == 2 ) {
10218 # Add the action to the line. (This is a <<, >>, or {{).
10219 push @$aref, action($line);
10223 # <<<, >>>>, {{{{{{ ... something not a command.
10225 "Confused by strange length of $which command($cmd)...\n";
10227 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
10229 } ## end sub cmd_prepost
10233 Contains the C<at_exit> routine that the debugger uses to issue the
10234 C<Debugged program terminated ...> message after the program completes. See
10235 the C<END> block documentation for more details.
10242 "Debugged program terminated. Use 'q' to quit or 'R' to restart.";
10245 package DB; # Do not trace this 1; below!