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";
874 # These variables control the execution of 'dumpvar.pl'.
889 # used to control die() reporting in diesignal()
892 use vars qw($CarpLevel);
895 # without threads, $filename is not defined until DB::DB is called
896 foreach my $k (keys (%INC)) {
897 share(\$main::{'_<'.$filename}) if defined $filename;
900 # Command-line + PERLLIB:
901 # Save the contents of @INC before they are modified elsewhere.
904 # This was an attempt to clear out the previous values of various
905 # trapped errors. Apparently it didn't help. XXX More info needed!
906 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
908 # We set these variables to safe values. We don't want to blindly turn
909 # off warnings, because other packages may still want them.
910 $trace = $signal = $single = 0; # Uninitialized warning suppression
911 # (local $^W cannot help - other packages!).
913 # Default to not exiting when program finishes; print the return
914 # value when the 'r' command is used to return from a subroutine.
915 $inhibit_exit = $option{PrintRet} = 1;
917 use vars qw($trace_to_depth);
919 # Default to 1E9 so it won't be limited to a certain recursion depth.
920 $trace_to_depth = 1E9;
922 =head1 OPTION PROCESSING
924 The debugger's options are actually spread out over the debugger itself and
925 C<dumpvar.pl>; some of these are variables to be set, while others are
926 subs to be called with a value. To try to make this a little easier to
927 manage, the debugger uses a few data structures to define what options
928 are legal and how they are to be processed.
930 First, the C<@options> array defines the I<names> of all the options that
936 CommandSet HistFile HistSize
937 hashDepth arrayDepth dumpDepth
938 DumpDBFiles DumpPackages DumpReused
939 compactDump veryCompact quote
940 HighBit undefPrint globPrint
941 PrintRet UsageOnly frame
943 ReadLine NonStop LineInfo
944 maxTraceLen recallCommand ShellBang
945 pager tkRunning ornaments
946 signalLevel warnLevel dieLevel
947 inhibit_exit ImmediateStop bareStringify
948 CreateTTY RemotePort windowSize
952 @RememberOnROptions = qw(DollarCaretP);
956 Second, C<optionVars> lists the variables that each option uses to save its
961 use vars qw(%optionVars);
964 hashDepth => \$dumpvar::hashDepth,
965 arrayDepth => \$dumpvar::arrayDepth,
966 CommandSet => \$CommandSet,
967 DumpDBFiles => \$dumpvar::dumpDBFiles,
968 DumpPackages => \$dumpvar::dumpPackages,
969 DumpReused => \$dumpvar::dumpReused,
970 HighBit => \$dumpvar::quoteHighBit,
971 undefPrint => \$dumpvar::printUndef,
972 globPrint => \$dumpvar::globPrint,
973 UsageOnly => \$dumpvar::usageOnly,
974 CreateTTY => \$CreateTTY,
975 bareStringify => \$dumpvar::bareStringify,
977 AutoTrace => \$trace,
978 inhibit_exit => \$inhibit_exit,
979 maxTraceLen => \$maxtrace,
980 ImmediateStop => \$ImmediateStop,
981 RemotePort => \$remoteport,
982 windowSize => \$window,
983 HistFile => \$histfile,
984 HistSize => \$histsize,
989 Third, C<%optionAction> defines the subroutine to be called to process each
994 use vars qw(%optionAction);
997 compactDump => \&dumpvar::compactDump,
998 veryCompact => \&dumpvar::veryCompact,
999 quote => \&dumpvar::quote,
1002 ReadLine => \&ReadLine,
1003 NonStop => \&NonStop,
1004 LineInfo => \&LineInfo,
1005 recallCommand => \&recallCommand,
1006 ShellBang => \&shellBang,
1008 signalLevel => \&signalLevel,
1009 warnLevel => \&warnLevel,
1010 dieLevel => \&dieLevel,
1011 tkRunning => \&tkRunning,
1012 ornaments => \&ornaments,
1013 RemotePort => \&RemotePort,
1014 DollarCaretP => \&DollarCaretP,
1019 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1024 # Note that this list is not complete: several options not listed here
1025 # actually require that dumpvar.pl be loaded for them to work, but are
1026 # not in the table. A subsequent patch will correct this problem; for
1027 # the moment, we're just recommenting, and we are NOT going to change
1029 use vars qw(%optionRequire);
1032 compactDump => 'dumpvar.pl',
1033 veryCompact => 'dumpvar.pl',
1034 quote => 'dumpvar.pl',
1039 There are a number of initialization-related variables which can be set
1040 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1041 variable. These are:
1045 =item C<$rl> - readline control XXX needs more explanation
1047 =item C<$warnLevel> - whether or not debugger takes over warning handling
1049 =item C<$dieLevel> - whether or not debugger takes over die handling
1051 =item C<$signalLevel> - whether or not debugger takes over signal handling
1053 =item C<$pre> - preprompt actions (array reference)
1055 =item C<$post> - postprompt actions (array reference)
1059 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1061 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1067 # These guys may be defined in $ENV{PERL5DB} :
1068 $rl = 1 unless defined $rl;
1069 $warnLevel = 1 unless defined $warnLevel;
1070 $dieLevel = 1 unless defined $dieLevel;
1071 $signalLevel = 1 unless defined $signalLevel;
1072 $pre = [] unless defined $pre;
1073 $post = [] unless defined $post;
1074 $pretype = [] unless defined $pretype;
1075 $CreateTTY = 3 unless defined $CreateTTY;
1076 $CommandSet = '580' unless defined $CommandSet;
1081 share($signalLevel);
1091 The default C<die>, C<warn>, and C<signal> handlers are set up.
1095 warnLevel($warnLevel);
1096 dieLevel($dieLevel);
1097 signalLevel($signalLevel);
1101 The pager to be used is needed next. We try to get it from the
1102 environment first. If it's not defined there, we try to find it in
1103 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1104 then call the C<pager()> function to save the pager name.
1108 # This routine makes sure $pager is set up so that '|' can use it.
1111 # If PAGER is defined in the environment, use it.
1115 # If not, see if Config.pm defines it.
1116 : eval { require Config }
1117 && defined $Config::Config{pager}
1118 ? $Config::Config{pager}
1120 # If not, fall back to 'more'.
1123 unless defined $pager;
1127 We set up the command to be used to access the man pages, the command
1128 recall character (C<!> unless otherwise defined) and the shell escape
1129 character (C<!> unless otherwise defined). Yes, these do conflict, and
1130 neither works in the debugger at the moment.
1136 # Set up defaults for command recall and shell escape (note:
1137 # these currently don't work in linemode debugging).
1138 recallCommand("!") unless defined $prc;
1139 shellBang("!") unless defined $psh;
1143 We then set up the gigantic string containing the debugger help.
1144 We also set the limit on the number of arguments we'll display during a
1151 # If we didn't get a default for the length of eval/stack trace args,
1153 $maxtrace = 400 unless defined $maxtrace;
1155 =head2 SETTING UP THE DEBUGGER GREETING
1157 The debugger I<greeting> helps to inform the user how many debuggers are
1158 running, and whether the current debugger is the primary or a child.
1160 If we are the primary, we just hang onto our pid so we'll have it when
1161 or if we start a child debugger. If we are a child, we'll set things up
1162 so we'll have a unique greeting and so the parent will give us our own
1165 We save the current contents of the C<PERLDB_PIDS> environment variable
1166 because we mess around with it. We'll also need to hang onto it because
1167 we'll need it if we restart.
1169 Child debuggers make a label out of the current PID structure recorded in
1170 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1171 yet so the parent will give them one later via C<resetterm()>.
1175 # Save the current contents of the environment; we're about to
1176 # much with it. We'll need this if we have to restart.
1177 use vars qw($ini_pids);
1178 $ini_pids = $ENV{PERLDB_PIDS};
1180 use vars qw ($pids $term_pid);
1182 if ( defined $ENV{PERLDB_PIDS} ) {
1184 # We're a child. Make us a label out of the current PID structure
1185 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1186 # a term yet so the parent will give us one later via resetterm().
1188 my $env_pids = $ENV{PERLDB_PIDS};
1189 $pids = "[$env_pids]";
1191 # Unless we are on OpenVMS, all programs under the DCL shell run under
1194 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1198 $ENV{PERLDB_PIDS} .= "->$$";
1202 } ## end if (defined $ENV{PERLDB_PIDS...
1205 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1206 # child debugger, and mark us as the parent, so we'll know to set up
1207 # more TTY's is we have to.
1208 $ENV{PERLDB_PIDS} = "$$";
1213 use vars qw($pidprompt);
1216 # Sets up $emacs as a synonym for $slave_editor.
1217 our ($slave_editor);
1218 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1220 =head2 READING THE RC FILE
1222 The debugger will read a file of initialization options if supplied. If
1223 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1227 # As noted, this test really doesn't check accurately that the debugger
1228 # is running at a terminal or not.
1230 use vars qw($rcfile);
1232 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1233 # this is the wrong metric!
1234 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
1239 The debugger does a safety test of the file to be read. It must be owned
1240 either by the current user or root, and must only be writable by the owner.
1244 # This wraps a safety test around "do" to read and evaluate the init file.
1246 # This isn't really safe, because there's a race
1247 # between checking and opening. The solution is to
1248 # open and fstat the handle, but then you have to read and
1249 # eval the contents. But then the silly thing gets
1250 # your lexical scope, which is unfortunate at best.
1254 # Just exactly what part of the word "CORE::" don't you understand?
1255 local $SIG{__WARN__};
1256 local $SIG{__DIE__};
1258 unless ( is_safe_file($file) ) {
1259 CORE::warn <<EO_GRIPE;
1260 perldb: Must not source insecure rcfile $file.
1261 You or the superuser must be the owner, and it must not
1262 be writable by anyone but its owner.
1265 } ## end unless (is_safe_file($file...
1268 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1269 } ## end sub safe_do
1271 # This is the safety test itself.
1273 # Verifies that owner is either real user or superuser and that no
1274 # one but owner may write to it. This function is of limited use
1275 # when called on a path instead of upon a handle, because there are
1276 # no guarantees that filename (by dirent) whose file (by ino) is
1277 # eventually accessed is the same as the one tested.
1278 # Assumes that the file's existence is not in doubt.
1281 stat($path) || return; # mysteriously vaporized
1282 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1284 return 0 if $uid != 0 && $uid != $<;
1285 return 0 if $mode & 022;
1287 } ## end sub is_safe_file
1289 # If the rcfile (whichever one we decided was the right one to read)
1290 # exists, we safely do it.
1292 safe_do("./$rcfile");
1295 # If there isn't one here, try the user's home directory.
1296 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1297 safe_do("$ENV{HOME}/$rcfile");
1300 # Else try the login directory.
1301 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1302 safe_do("$ENV{LOGDIR}/$rcfile");
1305 # If the PERLDB_OPTS variable has options in it, parse those out next.
1306 if ( defined $ENV{PERLDB_OPTS} ) {
1307 parse_options( $ENV{PERLDB_OPTS} );
1312 The last thing we do during initialization is determine which subroutine is
1313 to be used to obtain a new terminal when a new debugger is started. Right now,
1314 the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
1319 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1320 # Works if you're running an xterm or xterm-like window, or you're on
1321 # OS/2, or on Mac OS X. This may need some expansion.
1323 if (not defined &get_fork_TTY) # only if no routine exists
1325 if ( defined $remoteport ) {
1326 # Expect an inetd-like server
1327 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1329 elsif (defined $ENV{TERM} # If we know what kind
1330 # of terminal this is,
1331 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1332 and defined $ENV{DISPLAY} # and what display it's on,
1335 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1337 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1338 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1340 elsif ( $^O eq 'darwin' # If this is Mac OS X
1341 and defined $ENV{TERM_PROGRAM} # and we're running inside
1342 and $ENV{TERM_PROGRAM}
1343 eq 'Apple_Terminal' # Terminal.app
1346 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1348 } ## end if (not defined &get_fork_TTY...
1350 # untaint $^O, which may have been tainted by the last statement.
1351 # see bug [perl #24674]
1355 # Here begin the unreadable code. It needs fixing.
1357 =head2 RESTART PROCESSING
1359 This section handles the restart command. When the C<R> command is invoked, it
1360 tries to capture all of the state it can into environment variables, and
1361 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1362 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1363 the R command stuffed into the environment variables.
1365 PERLDB_RESTART - flag only, contains no restart data itself.
1366 PERLDB_HIST - command history, if it's available
1367 PERLDB_ON_LOAD - breakpoints set by the rc file
1368 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1369 PERLDB_VISITED - files that had breakpoints
1370 PERLDB_FILE_... - breakpoints for a file
1371 PERLDB_OPT - active options
1372 PERLDB_INC - the original @INC
1373 PERLDB_PRETYPE - preprompt debugger actions
1374 PERLDB_PRE - preprompt Perl code
1375 PERLDB_POST - post-prompt Perl code
1376 PERLDB_TYPEAHEAD - typeahead captured by readline()
1378 We chug through all these variables and plug the values saved in them
1379 back into the appropriate spots in the debugger.
1383 use vars qw(@truehist %postponed_file @typeahead);
1387 sub _restore_shared_globals_after_restart
1389 @hist = get_list('PERLDB_HIST');
1390 %break_on_load = get_list("PERLDB_ON_LOAD");
1391 %postponed = get_list("PERLDB_POSTPONE");
1395 share(%break_on_load);
1399 sub _restore_breakpoints_and_actions {
1401 my @had_breakpoints = get_list("PERLDB_VISITED");
1403 for my $file_idx ( 0 .. $#had_breakpoints ) {
1404 my $filename = $had_breakpoints[$file_idx];
1405 my %pf = get_list("PERLDB_FILE_$file_idx");
1406 $postponed_file{ $filename } = \%pf if %pf;
1407 my @lines = sort {$a <=> $b} keys(%pf);
1408 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1409 for my $line_idx (0 .. $#lines) {
1410 _set_breakpoint_enabled_status(
1413 ($enabled_statuses[$line_idx] ? 1 : ''),
1421 sub _restore_options_after_restart
1423 my %options_map = get_list("PERLDB_OPT");
1425 while ( my ( $opt, $val ) = each %options_map ) {
1426 $val =~ s/[\\\']/\\$1/g;
1427 parse_options("$opt'$val'");
1433 sub _restore_globals_after_restart
1435 # restore original @INC
1436 @INC = get_list("PERLDB_INC");
1439 # return pre/postprompt actions and typeahead buffer
1440 $pretype = [ get_list("PERLDB_PRETYPE") ];
1441 $pre = [ get_list("PERLDB_PRE") ];
1442 $post = [ get_list("PERLDB_POST") ];
1443 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1449 if ( exists $ENV{PERLDB_RESTART} ) {
1451 # We're restarting, so we don't need the flag that says to restart anymore.
1452 delete $ENV{PERLDB_RESTART};
1455 _restore_shared_globals_after_restart();
1457 _restore_breakpoints_and_actions();
1460 _restore_options_after_restart();
1462 _restore_globals_after_restart();
1463 } ## end if (exists $ENV{PERLDB_RESTART...
1465 =head2 SETTING UP THE TERMINAL
1467 Now, we'll decide how the debugger is going to interact with the user.
1468 If there's no TTY, we set the debugger to run non-stop; there's not going
1469 to be anyone there to enter commands.
1473 use vars qw($notty $console $tty $LINEINFO);
1474 use vars qw($lineinfo $doccmd);
1485 If there is a TTY, we have to determine who it belongs to before we can
1486 proceed. If this is a slave editor or graphical debugger (denoted by
1487 the first command-line switch being '-emacs'), we shift this off and
1488 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1494 # Is Perl being run from a slave editor or graphical debugger?
1495 # If so, don't use readline, and set $slave_editor = 1.
1496 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1501 #require Term::ReadLine;
1505 We then determine what the console should be on various systems:
1509 =item * Cygwin - We use C<stdin> instead of a separate device.
1513 if ( $^O eq 'cygwin' ) {
1515 # /dev/tty is binary. use stdin for textmode
1519 =item * Unix - use C</dev/tty>.
1523 elsif ( -e "/dev/tty" ) {
1524 $console = "/dev/tty";
1527 =item * Windows or MSDOS - use C<con>.
1531 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1535 =item * VMS - use C<sys$command>.
1541 # everything else is ...
1542 $console = "sys\$command";
1549 Several other systems don't use a specific console. We C<undef $console>
1550 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1551 with a slave editor, Epoc).
1555 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1557 # /dev/tty is binary. use stdin for textmode
1561 if ( $^O eq 'NetWare' ) {
1563 # /dev/tty is binary. use stdin for textmode
1567 # In OS/2, we need to use STDIN to get textmode too, even though
1568 # it pretty much looks like Unix otherwise.
1569 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1574 # EPOC also falls into the 'got to use STDIN' camp.
1575 if ( $^O eq 'epoc' ) {
1581 If there is a TTY hanging around from a parent, we use that as the console.
1585 $console = $tty if defined $tty;
1587 =head2 SOCKET HANDLING
1589 The debugger is capable of opening a socket and carrying out a debugging
1590 session over the socket.
1592 If C<RemotePort> was defined in the options, the debugger assumes that it
1593 should try to start a debugging session on that port. It builds the socket
1594 and then tries to connect the input and output filehandles to it.
1598 # Handle socket stuff.
1600 if ( defined $remoteport ) {
1602 # If RemotePort was defined in the options, connect input and output
1604 $IN = $OUT = connect_remoteport();
1605 } ## end if (defined $remoteport)
1609 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1610 this is probably a situation where multiple debuggers are running (for example,
1611 a backticked command that starts up another debugger). We create a new IN and
1612 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1620 # Two debuggers running (probably a system or a backtick that invokes
1621 # the debugger itself under the running one). create a new IN and OUT
1622 # filehandle, and do the necessary mojo to create a new tty if we
1623 # know how, and we can.
1624 create_IN_OUT(4) if $CreateTTY & 4;
1627 # If we have a console, check to see if there are separate ins and
1628 # outs to open. (They are assumed identical if not.)
1630 my ( $i, $o ) = split /,/, $console;
1631 $o = $i unless defined $o;
1633 # read/write on in, or just read, or read on STDIN.
1635 || open( IN, "<$i" )
1636 || open( IN, "<&STDIN" );
1638 # read/write/create/clobber out, or write/create/clobber out,
1639 # or merge with STDERR, or merge with STDOUT.
1641 || open( OUT, ">$o" )
1642 || open( OUT, ">&STDERR" )
1643 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1645 } ## end if ($console)
1646 elsif ( not defined $console ) {
1648 # No console. Open STDIN.
1649 open( IN, "<&STDIN" );
1651 # merge with STDERR, or with STDOUT.
1652 open( OUT, ">&STDERR" )
1653 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1654 $console = 'STDIN/OUT';
1655 } ## end elsif (not defined $console)
1657 # Keep copies of the filehandles so that when the pager runs, it
1658 # can close standard input without clobbering ours.
1659 if ($console or (not defined($console))) {
1663 } ## end elsif (from if(defined $remoteport))
1665 # Unbuffer DB::OUT. We need to see responses right away.
1668 # Line info goes to debugger output unless pointed elsewhere.
1669 # Pointing elsewhere makes it possible for slave editors to
1670 # keep track of file and position. We have both a filehandle
1671 # and a I/O description to keep track of.
1672 $LINEINFO = $OUT unless defined $LINEINFO;
1673 $lineinfo = $console unless defined $lineinfo;
1674 # share($LINEINFO); # <- unable to share globs
1679 To finish initialization, we show the debugger greeting,
1680 and then call the C<afterinit()> subroutine if there is one.
1684 # Show the debugger greeting.
1685 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1686 unless ($runnonstop) {
1689 if ( $term_pid eq '-1' ) {
1690 print $OUT "\nDaughter DB session started...\n";
1693 print $OUT "\nLoading DB routines from $header\n";
1696 $slave_editor ? "enabled" : "available", ".\n"
1699 "\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
1700 } ## end else [ if ($term_pid eq '-1')
1701 } ## end unless ($runnonstop)
1702 } ## end else [ if ($notty)
1704 # XXX This looks like a bug to me.
1705 # Why copy to @ARGS and then futz with @args?
1708 # Make sure backslashes before single quotes are stripped out, and
1709 # keep args unless they are numeric (XXX why?)
1710 # s/\'/\\\'/g; # removed while not justified understandably
1711 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1714 # If there was an afterinit() sub defined, call it. It will get
1715 # executed in our scope, so it can fiddle with debugger globals.
1716 if ( defined &afterinit ) { # May be defined in $rcfile
1720 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1721 use vars qw($I_m_init);
1725 ############################################################ Subroutines
1731 This gigantic subroutine is the heart of the debugger. Called before every
1732 statement, its job is to determine if a breakpoint has been reached, and
1733 stop if so; read commands from the user, parse them, and execute
1734 them, and then send execution off to the next statement.
1736 Note that the order in which the commands are processed is very important;
1737 some commands earlier in the loop will actually alter the C<$cmd> variable
1738 to create other commands to be executed later. This is all highly I<optimized>
1739 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1740 see what's happening in any given command.
1744 # $cmd cannot be an our() variable unfortunately (possible perl bug?).
1774 sub _DB__determine_if_we_should_break
1776 # if we have something here, see if we should break.
1777 # $stop is lexical and local to this block - $action on the other hand
1782 && _is_breakpoint_enabled($filename, $line)
1783 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1786 # Stop if the stop criterion says to just stop.
1787 if ( $stop eq '1' ) {
1791 # It's a conditional stop; eval it in the user's context and
1792 # see if we should stop. If so, remove the one-time sigil.
1794 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1796 # If the breakpoint is temporary, then delete its enabled status.
1797 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1798 _cancel_breakpoint_temp_enabled_status($filename, $line);
1801 } ## end if ($dbline{$line} && ...
1804 sub _DB__is_finished {
1805 if ($finished and $level <= 1) {
1814 sub _DB__read_next_cmd
1818 # We have a terminal, or can get one ...
1823 # ... and it belogs to this PID or we get one for this PID ...
1824 if ($term_pid != $$) {
1828 # ... and we got a line of command input ...
1829 $cmd = DB::readline(
1830 "$pidprompt $tid DB"
1833 . ( '>' x $level ) . " "
1836 return defined($cmd);
1839 sub _DB__trim_command_and_return_first_component {
1840 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1841 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1847 sub _DB__handle_f_command {
1848 if (($file) = $cmd =~ /\Af\b\s*(.*)/) {
1851 # help for no arguments (old-style was return from sub).
1854 "The old f command is now the r command.\n"; # hint
1855 print $OUT "The new f command switches filenames.\n";
1857 } ## end if (!$file)
1859 # if not in magic file list, try a close match.
1860 if ( !defined $main::{ '_<' . $file } ) {
1861 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1863 $try = substr( $try, 2 );
1864 print $OUT "Choosing $try matching '$file':\n";
1867 } ## end if (($try) = grep(m#^_<.*$file#...
1868 } ## end if (!defined $main::{ ...
1870 # If not successfully switched now, we failed.
1871 if ( !defined $main::{ '_<' . $file } ) {
1872 print $OUT "No file matching '$file' is loaded.\n";
1876 # We switched, so switch the debugger internals around.
1877 elsif ( $file ne $filename ) {
1878 *dbline = $main::{ '_<' . $file };
1883 } ## end elsif ($file ne $filename)
1885 # We didn't switch; say we didn't.
1887 print $OUT "Already in $file.\n";
1895 sub _DB__handle_dot_command {
1900 $incr = -1; # stay at current line
1902 # Reset everything to the old location.
1904 $filename = $filename_ini;
1905 *dbline = $main::{ '_<' . $filename };
1909 print_lineinfo($obj->position());
1916 sub _DB__handle_y_command {
1919 if (my ($match_level, $match_vars)
1920 = $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/) {
1922 # See if we've got the necessary support.
1923 if (!eval { require PadWalker; PadWalker->VERSION(0.08) }) {
1927 ? "PadWalker module not found - please install\n"
1933 # Load up dumpvar if we don't have it. If we can, that is.
1934 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1935 defined &main::dumpvar
1936 or print $OUT "dumpvar.pl not available.\n"
1939 # Got all the modules we need. Find them and print them.
1940 my @vars = split( ' ', $match_vars || '' );
1943 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
1945 # Oops. Can't find it.
1952 # Show the desired vars with dumplex().
1953 my $savout = select($OUT);
1955 # Have dumplex dump the lexicals.
1956 foreach my $key (sort keys %$h) {
1957 dumpvar::dumplex( $key, $h->{$key},
1958 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
1966 sub _DB__handle_c_command {
1969 if (my ($new_i) = $cmd =~ m#\Ac\b\s*([\w:]*)\s*\z#) {
1971 $obj->i_cmd($new_i);
1973 # Hey, show's over. The debugged program finished
1974 # executing already.
1975 next CMD if _DB__is_finished();
1977 # Capture the place to put a one-time break.
1978 $subname = $obj->i_cmd;
1980 # Probably not needed, since we finish an interactive
1981 # sub-session anyway...
1982 # local $filename = $filename;
1983 # local *dbline = *dbline; # XXX Would this work?!
1985 # The above question wonders if localizing the alias
1986 # to the magic array works or not. Since it's commented
1987 # out, we'll just leave that to speculation for now.
1989 # If the "subname" isn't all digits, we'll assume it
1990 # is a subroutine name, and try to find it.
1991 if ( $subname =~ /\D/ ) { # subroutine name
1992 # Qualify it to the current package unless it's
1993 # already qualified.
1994 $subname = $package . "::" . $subname
1995 unless $subname =~ /::/;
1997 # find_sub will return "file:line_number" corresponding
1998 # to where the subroutine is defined; we call find_sub,
1999 # break up the return value, and assign it in one
2001 ( $file, $new_i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2003 # Force the line number to be numeric.
2004 $obj->i_cmd($new_i + 0);
2006 # If we got a line number, we found the sub.
2009 # Switch all the debugger's internals around so
2010 # we're actually working with that file.
2012 *dbline = $main::{ '_<' . $filename };
2014 # Mark that there's a breakpoint in this file.
2015 $had_breakpoints{$filename} |= 1;
2017 # Scan forward to the first executable line
2018 # after the 'sub whatever' line.
2020 my $ii = $obj->i_cmd;
2021 ++$ii while $dbline[$ii] == 0 && $ii < $max;
2025 # We didn't find a sub by that name.
2027 print $OUT "Subroutine $subname not found.\n";
2030 } ## end if ($subname =~ /\D/)
2032 # At this point, either the subname was all digits (an
2033 # absolute line-break request) or we've scanned through
2034 # the code following the definition of the sub, looking
2035 # for an executable, which we may or may not have found.
2037 # If $i (which we set $subname from) is non-zero, we
2038 # got a request to break at some line somewhere. On
2039 # one hand, if there wasn't any real subroutine name
2040 # involved, this will be a request to break in the current
2041 # file at the specified line, so we have to check to make
2042 # sure that the line specified really is breakable.
2044 # On the other hand, if there was a subname supplied, the
2045 # preceding block has moved us to the proper file and
2046 # location within that file, and then scanned forward
2047 # looking for the next executable line. We have to make
2048 # sure that one was found.
2050 # On the gripping hand, we can't do anything unless the
2051 # current value of $i points to a valid breakable line.
2056 if ( $dbline[$obj->i_cmd] == 0 ) {
2057 print $OUT "Line " . $obj->i_cmd . " not breakable.\n";
2061 # Yes. Set up the one-time-break sigil.
2062 $dbline{$obj->i_cmd} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2063 _enable_breakpoint_temp_enabled_status($filename, $obj->i_cmd);
2066 # Turn off stack tracing from here up.
2067 for my $i (0 .. $stack_depth) {
2076 sub _DB__handle_forward_slash_command {
2079 # The pattern as a string.
2080 use vars qw($inpat);
2082 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2084 # Remove the final slash.
2085 $inpat =~ s:([^\\])/$:$1:;
2087 # If the pattern isn't null ...
2088 if ( $inpat ne "" ) {
2090 # Turn of warn and die procesing for a bit.
2091 local $SIG{__DIE__};
2092 local $SIG{__WARN__};
2094 # Create the pattern.
2095 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2098 # Oops. Bad pattern. No biscuit.
2099 # Print the eval error and go back for more
2105 } ## end if ($inpat ne "")
2107 # Set up to stop on wrap-around.
2110 # Don't move off the current line.
2113 my $pat = $obj->pat;
2115 # Done in eval so nothing breaks if the pattern
2116 # does something weird.
2121 # Move ahead one line.
2124 # Wrap if we pass the last line.
2125 $start = 1 if ($start > $max);
2127 # Stop if we have gotten back to this line again,
2128 last if ($start == $end);
2130 # A hit! (Note, though, that we are doing
2131 # case-insensitive matching. Maybe a qr//
2132 # expression would be better, so the user could
2133 # do case-sensitive matching if desired.
2134 if ($dbline[$start] =~ m/$pat/i) {
2135 if ($slave_editor) {
2136 # Handle proper escaping in the slave.
2137 print $OUT "\032\032$filename:$start:0\n";
2140 # Just print the line normally.
2141 print $OUT "$start:\t",$dbline[$start],"\n";
2143 # And quit since we found something.
2153 # If we wrapped, there never was a match.
2154 if ( $start == $end ) {
2155 print {$OUT} "/$pat/: not found\n";
2163 sub _DB__handle_question_mark_command {
2166 # ? - backward pattern search.
2167 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2169 # Get the pattern, remove trailing question mark.
2170 $inpat =~ s:([^\\])\?$:$1:;
2172 # If we've got one ...
2173 if ( $inpat ne "" ) {
2175 # Turn off die & warn handlers.
2176 local $SIG{__DIE__};
2177 local $SIG{__WARN__};
2178 eval '$inpat =~ m' . "\a$inpat\a";
2182 # Ouch. Not good. Print the error.
2187 } ## end if ($inpat ne "")
2189 # Where we are now is where to stop after wraparound.
2192 # Don't move away from this line.
2195 my $pat = $obj->pat;
2196 # Search inside the eval to prevent pattern badness
2204 # Wrap if we pass the first line.
2206 $start = $max if ($start <= 0);
2208 # Quit if we get back where we started,
2209 last if ($start == $end);
2212 if ($dbline[$start] =~ m/$pat/i) {
2213 if ($slave_editor) {
2214 # Yep, follow slave editor requirements.
2215 print $OUT "\032\032$filename:$start:0\n";
2218 # Yep, just print normally.
2219 print $OUT "$start:\t",$dbline[$start],"\n";
2228 # Say we failed if the loop never found anything,
2229 if ( $start == $end ) {
2230 print {$OUT} "?$pat?: not found\n";
2240 # lock the debugger and get the thread id for the prompt
2244 my ($prefix, $after, $infix);
2248 if ($ENV{PERL5DB_THREADED}) {
2249 $tid = eval { "[".threads->tid."]" };
2254 my $obj = DB::Obj->new(
2256 position => \$position,
2259 explicit_stop => \$explicit_stop,
2266 $obj->_DB_on_init__initialize_globals(@_);
2268 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2269 # The code being debugged may have altered them.
2272 # Since DB::DB gets called after every line, we can use caller() to
2273 # figure out where we last were executing. Sneaky, eh? This works because
2274 # caller is returning all the extra information when called from the
2276 local ( $package, $filename, $line ) = caller;
2277 $filename_ini = $filename;
2279 # set up the context for DB::eval, so it can properly execute
2280 # code on behalf of the user. We add the package in so that the
2281 # code is eval'ed in the proper package (not in the debugger!).
2282 local $usercontext = _calc_usercontext($package);
2284 # Create an alias to the active file magical array to simplify
2286 local (*dbline) = $main::{ '_<' . $filename };
2288 # Last line in the program.
2291 _DB__determine_if_we_should_break(@_);
2293 # Preserve the current stop-or-not, and see if any of the W
2294 # (watch expressions) has changed.
2295 my $was_signal = $signal;
2297 # If we have any watch expressions ...
2298 $obj->_DB__handle_watch_expressions(@_);
2300 =head2 C<watchfunction()>
2302 C<watchfunction()> is a function that can be defined by the user; it is a
2303 function which will be run on each entry to C<DB::DB>; it gets the
2304 current package, filename, and line as its parameters.
2306 The watchfunction can do anything it likes; it is executing in the
2307 debugger's context, so it has access to all of the debugger's internal
2308 data structures and functions.
2310 C<watchfunction()> can control the debugger's actions. Any of the following
2311 will cause the debugger to return control to the user's program after
2312 C<watchfunction()> executes:
2318 Returning a false value from the C<watchfunction()> itself.
2322 Altering C<$single> to a false value.
2326 Altering C<$signal> to a false value.
2330 Turning off the C<4> bit in C<$trace> (this also disables the
2331 check for C<watchfunction()>. This can be done with
2339 # If there's a user-defined DB::watchfunction, call it with the
2340 # current package, filename, and line. The function executes in
2342 if ( $trace & 4 ) { # User-installed watch
2344 if watchfunction( $package, $filename, $line )
2347 and not( $trace & ~4 );
2348 } ## end if ($trace & 4)
2350 # Pick up any alteration to $signal in the watchfunction, and
2351 # turn off the signal now.
2352 $was_signal = $signal;
2355 =head2 GETTING READY TO EXECUTE COMMANDS
2357 The debugger decides to take control if single-step mode is on, the
2358 C<t> command was entered, or the user generated a signal. If the program
2359 has fallen off the end, we set things up so that entering further commands
2360 won't cause trouble, and we say that the program is over.
2364 # Make sure that we always print if asked for explicitly regardless
2365 # of $trace_to_depth .
2366 $explicit_stop = ($single || $was_signal);
2368 # Check to see if we should grab control ($single true,
2369 # trace set appropriately, or we got a signal).
2370 if ( $explicit_stop || ( $trace & 1 ) ) {
2371 $obj->_DB__grab_control(@_);
2372 } ## end if ($single || ($trace...
2376 If there's an action to be executed for the line we stopped at, execute it.
2377 If there are any preprompt actions, execute those as well.
2381 # If there's an action, do it now.
2387 # Are we nested another level (e.g., did we evaluate a function
2388 # that had a breakpoint in it at the debugger prompt)?
2389 if ( $single || $was_signal ) {
2391 # Yes, go down a level.
2392 local $level = $level + 1;
2394 # Do any pre-prompt actions.
2395 foreach $evalarg (@$pre) {
2399 # Complain about too much recursion if we passed the limit.
2401 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2404 # The line we're currently on. Set $incr to -1 to stay here
2405 # until we get a command that tells us to advance.
2407 $incr = -1; # for backward motion.
2409 # Tack preprompt debugger actions ahead of any actual input.
2410 @typeahead = ( @$pretype, @typeahead );
2412 =head2 WHERE ARE WE?
2414 XXX Relocate this section?
2416 The debugger normally shows the line corresponding to the current line of
2417 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2418 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2420 C<$incr> controls by how many lines the I<current> line should move forward
2421 after a command is executed. If set to -1, this indicates that the I<current>
2422 line shouldn't change.
2424 C<$start> is the I<current> line. It is used for things like knowing where to
2425 move forwards or backwards from when doing an C<L> or C<-> command.
2427 C<$max> tells the debugger where the last line of the current file is. It's
2428 used to terminate loops most often.
2430 =head2 THE COMMAND LOOP
2432 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2439 The outer part of the loop, starting at the C<CMD> label. This loop
2440 reads a command and then executes it.
2444 The inner part of the loop, starting at the C<PIPE> label. This part
2445 is wholly contained inside the C<CMD> block and only executes a command.
2446 Used to handle commands running inside a pager.
2450 So why have two labels to restart the loop? Because sometimes, it's easier to
2451 have a command I<generate> another command and then re-execute the loop to do
2452 the new command. This is faster, but perhaps a bit more convoluted.
2456 # The big command dispatch loop. It keeps running until the
2457 # user yields up control again.
2459 # If we have a terminal for input, and we get something back
2460 # from readline(), keep on processing.
2465 while (_DB__read_next_cmd($tid))
2469 # ... try to execute the input as debugger commands.
2471 # Don't stop running.
2474 # No signal is active.
2477 # Handle continued commands (ending with \):
2478 if ($cmd =~ s/\\\z/\n/) {
2479 $cmd .= DB::readline(" cont: ");
2483 =head4 The null command
2485 A newline entered by itself means I<re-execute the last command>. We grab the
2486 command out of C<$laststep> (where it was recorded previously), and copy it
2487 back into C<$cmd> to be executed below. If there wasn't any previous command,
2488 we'll do nothing below (no command will match). If there was, we also save it
2489 in the command history and fall through to allow the command parsing to pick
2494 # Empty input means repeat the last command.
2498 chomp($cmd); # get rid of the annoying extra newline
2499 if (length($cmd) >= 2) {
2500 push( @hist, $cmd );
2502 push( @truehist, $cmd );
2506 # This is a restart point for commands that didn't arrive
2507 # via direct user input. It allows us to 'redo PIPE' to
2508 # re-execute command processing without reading a new command.
2510 $i = _DB__trim_command_and_return_first_component();
2512 =head3 COMMAND ALIASES
2514 The debugger can create aliases for commands (these are stored in the
2515 C<%alias> hash). Before a command is executed, the command loop looks it up
2516 in the alias hash and substitutes the contents of the alias for the command,
2517 completely replacing it.
2521 # See if there's an alias for the command, and set it up if so.
2524 # Squelch signal handling; we want to keep control here
2525 # if something goes loco during the alias eval.
2526 local $SIG{__DIE__};
2527 local $SIG{__WARN__};
2529 # This is a command, so we eval it in the DEBUGGER's
2530 # scope! Otherwise, we can't see the special debugger
2531 # variables, or get to the debugger's subs. (Well, we
2532 # _could_, but why make it even more complicated?)
2533 eval "\$cmd =~ $alias{$i}";
2536 print $OUT "Couldn't evaluate '$i' alias: $@";
2539 } ## end if ($alias{$i})
2541 =head3 MAIN-LINE COMMANDS
2543 All of these commands work up to and after the program being debugged has
2548 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2549 try to execute further, cleaning any restart-related stuff out of the
2550 environment, and executing with the last value of C<$?>.
2560 =head4 C<t> - trace [n]
2562 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2563 If level is specified, set C<$trace_to_depth>.
2567 $obj->_handle_t_command;
2569 =head4 C<S> - list subroutines matching/not matching a pattern
2571 Walks through C<%sub>, checking to see whether or not to print the name.
2575 $obj->_handle_S_command;
2577 =head4 C<X> - list variables in current package
2579 Since the C<V> command actually processes this, just change this to the
2580 appropriate C<V> command and fall through.
2582 =head4 C<V> - list variables
2584 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2588 $obj->_handle_V_command_and_X_command;
2590 =head4 C<x> - evaluate and print an expression
2592 Hands the expression off to C<DB::eval>, setting it up to print the value
2593 via C<dumpvar.pl> instead of just printing it directly.
2597 if ($cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
2598 $onetimeDump = 'dump'; # main::dumpvar shows the output
2600 # handle special "x 3 blah" syntax XXX propagate
2601 # doc back to special variables.
2602 if ( $cmd =~ s#\A\s*(\d+)(?=\s)# #) {
2603 $onetimedumpDepth = $1;
2607 =head4 C<m> - print methods
2609 Just uses C<DB::methods> to determine what methods are available.
2613 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2618 # m expr - set up DB::eval to do the work
2619 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2620 $onetimeDump = 'methods'; # method output gets used there
2623 =head4 C<f> - switch files
2627 _DB__handle_f_command();
2629 =head4 C<.> - return to last-executed line.
2631 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2632 and then we look up the line in the magical C<%dbline> hash.
2636 _DB__handle_dot_command($obj);
2638 =head4 C<-> - back one window
2640 We change C<$start> to be one window back; if we go back past the first line,
2641 we set it to be the first line. We ser C<$incr> to put us back at the
2642 currently-executing line, and then put a C<l $start +> (list one window from
2643 C<$start>) in C<$cmd> to be executed later.
2647 # - - back a window.
2648 $obj->_handle_dash_command;
2650 =head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
2652 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2653 problems, most notably that the default case of several commands destroying
2654 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2655 retain the old commands for those who were used to using them or who preferred
2656 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2657 deal with them instead of processing them in-line.
2661 # All of these commands were remapped in perl 5.8.0;
2662 # we send them off to the secondary dispatcher (see below).
2663 if (my ($cmd_letter, $my_arg) = $cmd =~ /\A([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so) {
2664 &cmd_wrapper( $cmd_letter, $my_arg, $line );
2668 =head4 C<y> - List lexicals in higher scope
2670 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2671 above the current one and then displays then using C<dumpvar.pl>.
2675 _DB__handle_y_command($obj);
2677 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2679 All of the commands below this point don't work after the program being
2680 debugged has ended. All of them check to see if the program has ended; this
2681 allows the commands to be relocated without worrying about a 'line of
2682 demarcation' above which commands can be entered anytime, and below which
2685 =head4 C<n> - single step, but don't trace down into subs
2687 Done by setting C<$single> to 2, which forces subs to execute straight through
2688 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2689 so a null command knows what to re-execute.
2694 $obj->_handle_n_command;
2696 =head4 C<s> - single-step, entering subs
2698 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2699 subs. Also saves C<s> as C<$lastcmd>.
2703 $obj->_handle_s_command;
2705 =head4 C<c> - run continuously, setting an optional breakpoint
2707 Most of the code for this command is taken up with locating the optional
2708 breakpoint, which is either a subroutine name or a line number. We set
2709 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2710 in this and all call levels above this one.
2714 # c - start continuous execution.
2715 _DB__handle_c_command($obj);
2717 =head4 C<r> - return from a subroutine
2719 For C<r> to work properly, the debugger has to stop execution again
2720 immediately after the return is executed. This is done by forcing
2721 single-stepping to be on in the call level above the current one. If
2722 we are printing return values when a C<r> is executed, set C<$doret>
2723 appropriately, and force us out of the command loop.
2727 # r - return from the current subroutine.
2728 $obj->_handle_r_command;
2730 =head4 C<T> - stack trace
2732 Just calls C<DB::print_trace>.
2736 $obj->_handle_T_command;
2738 =head4 C<w> - List window around current line.
2740 Just calls C<DB::cmd_w>.
2744 $obj->_handle_w_command;
2746 =head4 C<W> - watch-expression processing.
2748 Just calls C<DB::cmd_W>.
2752 $obj->_handle_W_command;
2754 =head4 C</> - search forward for a string in the source
2756 We take the argument and treat it as a pattern. If it turns out to be a
2757 bad one, we return the error we got from trying to C<eval> it and exit.
2758 If not, we create some code to do the search and C<eval> it so it can't
2763 _DB__handle_forward_slash_command($obj);
2765 =head4 C<?> - search backward for a string in the source
2767 Same as for C</>, except the loop runs backwards.
2771 _DB__handle_question_mark_command($obj);
2773 =head4 C<$rc> - Recall command
2775 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2776 that the terminal supports history). It find the the command required, puts it
2777 into C<$cmd>, and redoes the loop to execute it.
2781 # $rc - recall command.
2782 $obj->_handle_rc_recall_command;
2784 =head4 C<$sh$sh> - C<system()> command
2786 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2787 C<STDOUT> from getting messed up.
2791 # $sh$sh - run a shell command (if it's all ASCII).
2792 # Can't run shell commands with Unicode in the debugger, hmm.
2793 if (my ($arg) = $cmd =~ m#\A$sh$sh\s*(.*)#ms) {
2800 =head4 C<$rc I<pattern> $rc> - Search command history
2802 Another command to manipulate C<@hist>: this one searches it with a pattern.
2803 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
2807 # $rc pattern $rc - find a command in the history.
2808 if (my ($arg) = $cmd =~ /\A$rc([^$rc].*)\z/) {
2810 # Create the pattern to use.
2813 # Toss off last entry if length is >1 (and it always is).
2814 pop(@hist) if length($cmd) > 1;
2816 # Look backward through the history.
2817 for ( $i = $#hist ; $i ; --$i ) {
2818 # Stop if we find it.
2819 last if $hist[$i] =~ /$pat/;
2825 print $OUT "No such command!\n\n";
2829 # Found it. Put it in the buffer, print it, and process it.
2831 print $OUT $cmd, "\n";
2835 =head4 C<$sh> - Invoke a shell
2837 Uses C<DB::system> to invoke a shell.
2841 # $sh - start a shell.
2842 if ($cmd =~ /\A$sh\z/) {
2844 # Run the user's shell. If none defined, run Bourne.
2845 # We resume execution when the shell terminates.
2846 &system( $ENV{SHELL} || "/bin/sh" );
2850 =head4 C<$sh I<command>> - Force execution of a command in a shell
2852 Like the above, but the command is passed to the shell. Again, we use
2853 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
2857 # $sh command - start a shell and run a command in it.
2858 if (my ($arg) = $cmd =~ m#\A$sh\s*(.*)#ms) {
2860 # XXX: using csh or tcsh destroys sigint retvals!
2861 #&system($1); # use this instead
2863 # use the user's shell, or Bourne if none defined.
2864 &system( $ENV{SHELL} || "/bin/sh", "-c", $arg );
2868 =head4 C<H> - display commands in history
2870 Prints the contents of C<@hist> (if any).
2874 if ($cmd =~ /\AH\b\s*\*/) {
2875 @hist = @truehist = ();
2876 print $OUT "History cleansed\n";
2881 = $cmd =~ /\AH\b\s*(?:-(\d+))?/) {
2883 # Anything other than negative numbers is ignored by
2884 # the (incorrect) pattern, so this test does nothing.
2885 $end = $num ? ( $#hist - $num ) : 0;
2887 # Set to the minimum if less than zero.
2888 $hist = 0 if $hist < 0;
2890 # Start at the end of the array.
2891 # Stay in while we're still above the ending value.
2892 # Tick back by one each time around the loop.
2893 for ( $i = $#hist ; $i > $end ; $i-- ) {
2895 # Print the command unless it has no arguments.
2896 print $OUT "$i: ", $hist[$i], "\n"
2897 unless $hist[$i] =~ /^.?$/;
2902 =head4 C<man, doc, perldoc> - look up documentation
2904 Just calls C<runman()> to print the appropriate document.
2908 # man, perldoc, doc - show manual pages.
2910 = $cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
2917 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
2918 the bottom of the loop.
2922 my $print_cmd = 'print {$DB::OUT} ';
2923 # p - print (no args): print $_.
2925 $cmd = $print_cmd . '$_';
2928 # p - print the given expression.
2929 $cmd =~ s/\Ap\b/$print_cmd /;
2931 =head4 C<=> - define command alias
2933 Manipulates C<%alias> to add or list command aliases.
2937 # = - set up a command alias.
2938 if ($cmd =~ s/\A=\s*//) {
2940 if ( length $cmd == 0 ) {
2942 # No args, get current aliases.
2943 @keys = sort keys %alias;
2945 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
2947 # Creating a new alias. $k is alias name, $v is
2950 # can't use $_ or kill //g state
2951 for my $x ( $k, $v ) {
2953 # Escape "alarm" characters.
2957 # Substitute key for value, using alarm chars
2958 # as separators (which is why we escaped them in
2960 $alias{$k} = "s\a$k\a$v\a";
2962 # Turn off standard warn and die behavior.
2963 local $SIG{__DIE__};
2964 local $SIG{__WARN__};
2967 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
2969 # Nope. Bad alias. Say so and get out.
2970 print $OUT "Can't alias $k to $v: $@\n";
2975 # We'll only list the new one.
2977 } ## end elsif (my ($k, $v) = ($cmd...
2979 # The argument is the alias to list.
2987 # Messy metaquoting: Trim the substitution code off.
2988 # We use control-G as the delimiter because it's not
2989 # likely to appear in the alias.
2990 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
2993 print $OUT "$k\t= $1\n";
2995 elsif ( defined $alias{$k} ) {
2997 # Couldn't trim it off; just print the alias code.
2998 print $OUT "$k\t$alias{$k}\n";
3003 print "No alias for $k\n";
3005 } ## end for my $k (@keys)
3009 =head4 C<source> - read commands from a file.
3011 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3016 # source - read commands from a file (or pipe!) and execute.
3017 if (my ($sourced_fn) = $cmd =~ /\Asource\s+(.*\S)/) {
3018 if ( open my $fh, $sourced_fn ) {
3020 # Opened OK; stick it in the list of file handles.
3026 &warn("Can't execute '$sourced_fn': $!\n");
3031 if (my ($which_cmd, $position)
3032 = $cmd =~ /^(enable|disable)\s+(\S+)\s*$/) {
3034 my ($fn, $line_num);
3035 if ($position =~ m{\A\d+\z})
3038 $line_num = $position;
3040 elsif (my ($new_fn, $new_line_num)
3041 = $position =~ m{\A(.*):(\d+)\z}) {
3042 ($fn, $line_num) = ($new_fn, $new_line_num);
3046 &warn("Wrong spec for enable/disable argument.\n");
3050 if (_has_breakpoint_data_ref($fn, $line_num)) {
3051 _set_breakpoint_enabled_status($fn, $line_num,
3052 ($which_cmd eq 'enable' ? 1 : '')
3056 &warn("No breakpoint set at ${fn}:${line_num}\n");
3063 =head4 C<save> - send current history to a file
3065 Takes the complete history, (not the shrunken version you see with C<H>),
3066 and saves it to the given filename, so it can be replayed using C<source>.
3068 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3072 # save source - write commands to a file for later use
3073 if (my ($new_fn) = $cmd =~ /\Asave\s*(.*)\z/) {
3074 my $filename = $new_fn || '.perl5dbrc'; # default?
3075 if ( open my $fh, '>', $filename ) {
3077 # chomp to remove extraneous newlines from source'd files
3078 chomp( my @truelist =
3079 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3081 print $fh join( "\n", @truelist );
3082 print "commands saved in $file\n";
3085 &warn("Can't save debugger commands in '$new_fn': $!\n");
3090 =head4 C<R> - restart
3092 Restart the debugger session.
3094 =head4 C<rerun> - rerun the current session
3096 Return to any given position in the B<true>-history list
3100 # R - restart execution.
3101 # rerun - controlled restart execution.
3102 if (my ($cmd_cmd, $cmd_params) =
3103 $cmd =~ /\A((?:R)|(?:rerun\s*(.*)))\z/) {
3104 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
3106 # Close all non-system fds for a clean restart. A more
3107 # correct method would be to close all fds that were not
3108 # open when the process started, but this seems to be
3109 # hard. See "debugger 'R'estart and open database
3110 # connections" on p5p.
3112 my $max_fd = 1024; # default if POSIX can't be loaded
3113 if (eval { require POSIX }) {
3114 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
3117 if (defined $max_fd) {
3118 foreach ($^F+1 .. $max_fd-1) {
3119 next unless open FD_TO_CLOSE, "<&=$_";
3124 # And run Perl again. We use exec() to keep the
3125 # PID stable (and that way $ini_pids is still valid).
3126 exec(@args) || print $OUT "exec failed: $!\n";
3131 =head4 C<|, ||> - pipe output through the pager.
3133 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3134 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3135 pipe to the pager (restoring the output filehandles if this fails). If this
3136 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3137 set C<$signal>, sending us back into the debugger.
3139 We then trim off the pipe symbols and C<redo> the command loop at the
3140 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3145 # || - run command in the pager, with output to DB::OUT.
3146 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
3147 if ( $pager =~ /^\|/ ) {
3149 # Default pager is into a pipe. Redirect I/O.
3150 open( SAVEOUT, ">&STDOUT" )
3151 || &warn("Can't save STDOUT");
3152 open( STDOUT, ">&OUT" )
3153 || &warn("Can't redirect STDOUT");
3154 } ## end if ($pager =~ /^\|/)
3157 # Not into a pipe. STDOUT is safe.
3158 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3161 # Fix up environment to record we have less if so.
3164 unless ( $piped = open( OUT, $pager ) ) {
3166 # Couldn't open pipe to pager.
3167 &warn("Can't pipe output to '$pager'");
3168 if ( $pager =~ /^\|/ ) {
3170 # Redirect I/O back again.
3171 open( OUT, ">&STDOUT" ) # XXX: lost message
3172 || &warn("Can't restore DB::OUT");
3173 open( STDOUT, ">&SAVEOUT" )
3174 || &warn("Can't restore STDOUT");
3176 } ## end if ($pager =~ /^\|/)
3179 # Redirect I/O. STDOUT already safe.
3180 open( OUT, ">&STDOUT" ) # XXX: lost message
3181 || &warn("Can't restore DB::OUT");
3184 } ## end unless ($piped = open(OUT,...
3186 # Set up broken-pipe handler if necessary.
3187 $SIG{PIPE} = \&DB::catch
3189 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
3192 # Save current filehandle, and put it back.
3193 $selected = select(OUT);
3194 # Don't put it back if pager was a pipe.
3195 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
3197 # Trim off the pipe symbols and run the command now.
3198 $cmd =~ s#\A\|+\s*##;
3202 =head3 END OF COMMAND PARSING
3204 Anything left in C<$cmd> at this point is a Perl expression that we want to
3205 evaluate. We'll always evaluate in the user's context, and fully qualify
3206 any variables we might want to address in the C<DB> package.
3210 # t - turn trace on.
3211 if ($cmd =~ s#\At\s+(\d+)?#\$DB::trace |= 1;\n#) {
3213 $trace_to_depth = $trace_arg ? $stack_depth||0 + $1 : 1E9;
3216 # s - single-step. Remember the last command was 's'.
3217 if ($cmd =~ s/\As\s/\$DB::single = 1;\n/) {
3221 # n - single-step, but not into subs. Remember last command
3223 if ($cmd =~ s#\An\s#\$DB::single = 2;\n#) {
3229 # Make sure the flag that says "the debugger's running" is
3230 # still on, to make sure we get control again.
3231 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3233 # Run *our* eval that executes in the caller's context.
3236 # Turn off the one-time-dump stuff now.
3238 $onetimeDump = undef;
3239 $onetimedumpDepth = undef;
3241 elsif ( $term_pid == $$ ) {
3242 eval { # May run under miniperl, when not available...
3247 # XXX If this is the master pid, print a newline.
3250 } ## end while (($term || &setterm...
3252 =head3 POST-COMMAND PROCESSING
3254 After each command, we check to see if the command output was piped anywhere.
3255 If so, we go through the necessary code to unhook the pipe and go back to
3256 our standard filehandles for input and output.
3262 # At the end of every command:
3265 # Unhook the pipe mechanism now.
3266 if ( $pager =~ /^\|/ ) {
3268 # No error from the child.
3271 # we cannot warn here: the handle is missing --tchrist
3272 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
3274 # most of the $? crud was coping with broken cshisms
3275 # $? is explicitly set to 0, so this never runs.
3277 print SAVEOUT "Pager '$pager' failed: ";
3279 print SAVEOUT "shell returned -1\n";
3282 print SAVEOUT ( $? & 127 )
3283 ? " (SIG#" . ( $? & 127 ) . ")"
3284 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3287 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3291 # Reopen filehandle for our output (if we can) and
3292 # restore STDOUT (if we can).
3293 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3294 open( STDOUT, ">&SAVEOUT" )
3295 || &warn("Can't restore STDOUT");
3297 # Turn off pipe exception handler if necessary.
3298 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
3300 # Will stop ignoring SIGPIPE if done like nohup(1)
3301 # does SIGINT but Perl doesn't give us a choice.
3302 } ## end if ($pager =~ /^\|/)
3305 # Non-piped "pager". Just restore STDOUT.
3306 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3309 # Close filehandle pager was using, restore the normal one
3312 select($selected), $selected = "" unless $selected eq "";
3316 } ## end if ($piped)
3319 =head3 COMMAND LOOP TERMINATION
3321 When commands have finished executing, we come here. If the user closed the
3322 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3323 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3324 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3325 The interpreter will then execute the next line and then return control to us
3330 # No more commands? Quit.
3331 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
3333 # Evaluate post-prompt commands.
3334 foreach $evalarg (@$post) {
3337 } # if ($single || $signal)
3339 # Put the user's globals back where you found them.
3340 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3349 my $self = bless {}, $class;
3357 my ($self, $args) = @_;
3359 %{$self} = (%$self, %$args);
3366 foreach my $slot_name (qw(
3367 after explicit_stop infix pat position prefix i_cmd
3369 my $slot = $slot_name;
3374 ${ $self->{$slot} } = shift;
3377 return ${ $self->{$slot} };
3380 *{"append_to_$slot"} = sub {
3384 return $self->$slot($self->$slot . $s);
3389 sub _DB_on_init__initialize_globals
3393 # Check for whether we should be running continuously or not.
3394 # _After_ the perl program is compiled, $single is set to 1:
3395 if ( $single and not $second_time++ ) {
3397 # Options say run non-stop. Run until we get an interrupt.
3398 if ($runnonstop) { # Disable until signal
3399 # If there's any call stack in place, turn off single
3400 # stepping into subs throughout the stack.
3401 for my $i (0 .. $stack_depth) {
3405 # And we are now no longer in single-step mode.
3408 # If we simply returned at this point, we wouldn't get
3409 # the trace info. Fall on through.
3411 } ## end if ($runnonstop)
3413 elsif ($ImmediateStop) {
3415 # We are supposed to stop here; XXX probably a break.
3416 $ImmediateStop = 0; # We've processed it; turn it off
3417 $signal = 1; # Simulate an interrupt to force
3418 # us into the command loop
3420 } ## end if ($single and not $second_time...
3422 # If we're in single-step mode, or an interrupt (real or fake)
3423 # has occurred, turn off non-stop mode.
3424 $runnonstop = 0 if $single or $signal;
3429 sub _DB__handle_watch_expressions
3434 for my $n (0 .. $#to_watch) {
3435 $evalarg = $to_watch[$n];
3436 local $onetimeDump; # Tell DB::eval() to not output results
3438 # Fix context DB::eval() wants to return an array, but
3439 # we need a scalar here.
3440 my ($val) = join( "', '", DB::eval() );
3441 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
3444 if ( $val ne $old_watch[$n] ) {
3446 # Yep! Show the difference, and fake an interrupt.
3449 Watchpoint $n:\t$to_watch[$n] changed:
3450 old value:\t$old_watch[$n]
3453 $old_watch[$n] = $val;
3454 } ## end if ($val ne $old_watch...
3455 } ## end for my $n (0 ..
3456 } ## end if ($trace & 2)
3461 sub _my_print_lineinfo
3463 my ($self, $i, $incr_pos) = @_;
3466 # Print it indented if tracing is on.
3467 DB::print_lineinfo( ' ' x $stack_depth,
3468 "$i:\t$DB::dbline[$i]" . $self->after );
3471 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3476 return $DB::dbline[$line];
3479 sub _DB__grab_control
3483 # Yes, grab control.
3484 if ($slave_editor) {
3486 # Tell the editor to update its position.
3487 $self->position("\032\032${DB::filename}:$line:0\n");
3488 DB::print_lineinfo($self->position());
3493 Special check: if we're in package C<DB::fake>, we've gone through the
3494 C<END> block at least once. We set up everything so that we can continue
3495 to enter commands and have a valid context to be in.
3499 elsif ( $DB::package eq 'DB::fake' ) {
3501 # Fallen off the end already.
3506 DB::print_help(<<EOP);
3507 Debugged program terminated. Use B<q> to quit or B<R> to restart,
3508 use B<o> I<inhibit_exit> to avoid stopping after program termination,
3509 B<h q>, B<h R> or B<h o> to get additional info.
3512 # Set the DB::eval context appropriately.
3513 $DB::package = 'main';
3514 $DB::usercontext = DB::_calc_usercontext($DB::package);
3515 } ## end elsif ($package eq 'DB::fake')
3519 If the program hasn't finished executing, we scan forward to the
3520 next executable line, print that out, build the prompt from the file and line
3521 number information, and print that.
3528 # Still somewhere in the midst of execution. Set up the
3530 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3531 # Perl 5 ones (sorry, we don't print Klingon
3534 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
3535 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
3536 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
3538 # Break up the prompt if it's really long.
3539 if ( length($self->prefix()) > 30 ) {
3540 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
3542 $self->infix(":\t");
3545 $self->infix("):\t");
3547 $self->prefix . $line. $self->infix
3548 . $self->_curr_line . $self->after
3552 # Print current line info, indenting if necessary.
3553 $self->_my_print_lineinfo($line, $self->position);
3556 my $line_i = sub { return $DB::dbline[$i]; };
3558 # Scan forward, stopping at either the end or the next
3560 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
3563 # Drop out on null statements, block closers, and comments.
3564 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
3566 # Drop out if the user interrupted us.
3569 # Append a newline if the line doesn't have one. Can happen
3570 # in eval'ed text, for instance.
3571 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
3573 # Next executable line.
3574 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
3576 $self->append_to_position($incr_pos);
3577 $self->_my_print_lineinfo($i, $incr_pos);
3578 } ## end for ($i = $line + 1 ; $i...
3579 } ## end else [ if ($slave_editor)
3584 sub _handle_t_command {
3585 if (my ($levels) = $DB::cmd =~ /\At(?:\s+(\d+))?\z/) {
3588 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3589 print {$OUT} "Trace = "
3591 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3600 sub _handle_S_command {
3601 if (my ($print_all_subs, $should_reverse, $Spatt)
3602 = $DB::cmd =~ /\AS(\s+(!)?(.+))?\z/) {
3603 # $Spatt is the pattern (if any) to use.
3605 my $Srev = defined $should_reverse;
3606 # No args - print all subs.
3607 my $Snocheck = !defined $print_all_subs;
3609 # Need to make these sane here.
3613 # Search through the debugger's magical hash of subs.
3614 # If $nocheck is true, just print the sub name.
3615 # Otherwise, check it against the pattern. We then use
3616 # the XOR trick to reverse the condition as required.
3617 foreach $subname ( sort( keys %sub ) ) {
3618 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3619 print $OUT $subname, "\n";
3628 sub _handle_V_command_and_X_command {
3630 $DB::cmd =~ s/^X\b/V $DB::package/;
3632 # Bare V commands get the currently-being-debugged package
3634 if ($DB::cmd eq "V") {
3635 $DB::cmd = "V $DB::package";
3638 # V - show variables in package.
3639 if (my ($new_packname, $new_vars_str) =
3640 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3642 # Save the currently selected filehandle and
3643 # force output to debugger's filehandle (dumpvar
3644 # just does "print" for output).
3645 my $savout = select($OUT);
3647 # Grab package name and variables to dump.
3648 $packname = $new_packname;
3649 my @vars = split( ' ', $new_vars_str );
3651 # If main::dumpvar isn't here, get it.
3652 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3653 if ( defined &main::dumpvar ) {
3655 # We got it. Turn off subroutine entry/exit messages
3656 # for the moment, along with return values.
3660 # must detect sigpipe failures - not catching
3661 # then will cause the debugger to die.
3665 defined $option{dumpDepth}
3666 ? $option{dumpDepth}
3667 : -1, # assume -1 unless specified
3672 # The die doesn't need to include the $@, because
3673 # it will automatically get propagated for us.
3675 die unless $@ =~ /dumpvar print failed/;
3677 } ## end if (defined &main::dumpvar)
3680 # Couldn't load dumpvar.
3681 print $OUT "dumpvar.pl not available.\n";
3684 # Restore the output filehandle, and go round again.
3692 sub _handle_dash_command {
3694 if ($DB::cmd eq '-') {
3696 # back up by a window; go to 1 if back too far.
3697 $start -= $incr + $window + 1;
3698 $start = 1 if $start <= 0;
3699 $incr = $window - 1;
3701 # Generate and execute a "l +" command (handled below).
3702 $DB::cmd = 'l ' . ($start) . '+';
3707 sub _n_or_s_commands_generic {
3708 my ($self, $new_val) = @_;
3710 next CMD if DB::_DB__is_finished();
3712 # Single step, but don't enter subs.
3715 # Save for empty command (repeat last).
3716 $laststep = $DB::cmd;
3721 my ($self, $letter, $new_val) = @_;
3723 if ($DB::cmd eq $letter) {
3724 $self->_n_or_s_commands_generic($new_val);
3730 sub _handle_n_command {
3733 return $self->_n_or_s('n', 2);
3736 sub _handle_s_command {
3739 return $self->_n_or_s('s', 1);
3742 sub _handle_r_command {
3744 # r - return from the current subroutine.
3745 if ($DB::cmd eq 'r') {
3747 # Can't do anything if the program's over.
3748 next CMD if DB::_DB__is_finished();
3750 # Turn on stack trace.
3751 $stack[$stack_depth] |= 1;
3753 # Print return value unless the stack is empty.
3754 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3761 sub _handle_T_command {
3762 if ($DB::cmd eq 'T') {
3763 DB::print_trace( $OUT, 1 ); # skip DB
3770 sub _handle_w_command {
3771 if (my ($arg) = $DB::cmd =~ /\Aw\b\s*(.*)/s) {
3772 DB::cmd_w( 'w', $arg );
3779 sub _handle_W_command {
3780 if (my ($arg) = $DB::cmd =~ /\AW\b\s*(.*)/s) {
3781 DB::cmd_W( 'W', $arg );
3788 sub _handle_rc_recall_command {
3791 # $rc - recall command.
3792 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3794 # No arguments, take one thing off history.
3795 pop(@hist) if length($DB::cmd) > 1;
3797 # Relative (- found)?
3798 # Y - index back from most recent (by 1 if bare minus)
3799 # N - go to that particular command slot or the last
3800 # thing if nothing following.
3801 my $new_i = $minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist );
3803 $self->i_cmd($new_i);
3805 # Pick out the command desired.
3806 $DB::cmd = $hist[$self->i_cmd];
3808 # Print the command to be executed and restart the loop
3809 # with that command in the buffer.
3810 print {$OUT} $DB::cmd, "\n";
3819 # The following code may be executed now:
3824 C<sub> is called whenever a subroutine call happens in the program being
3825 debugged. The variable C<$DB::sub> contains the name of the subroutine
3828 The core function of this subroutine is to actually call the sub in the proper
3829 context, capturing its output. This of course causes C<DB::DB> to get called
3830 again, repeating until the subroutine ends and returns control to C<DB::sub>
3831 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3832 return value, and returns its captured copy of the return value as its own
3833 return value. The value then feeds back into the program being debugged as if
3834 C<DB::sub> hadn't been there at all.
3836 C<sub> does all the work of printing the subroutine entry and exit messages
3837 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3838 and also prints the return value if needed (for the C<r> command and if
3839 the 16 bit is set in C<$frame>).
3841 It also tracks the subroutine call depth by saving the current setting of
3842 C<$single> in the C<@stack> package global; if this exceeds the value in
3843 C<$deep>, C<sub> automatically turns on printing of the current depth by
3844 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
3845 of stop/don't stop on entry to subs set as it currently is set.
3847 =head3 C<caller()> support
3849 If C<caller()> is called from the package C<DB>, it provides some
3850 additional data, in the following order:
3856 The package name the sub was in
3858 =item * C<$filename>
3860 The filename it was defined in
3864 The line number it was defined on
3866 =item * C<$subroutine>
3868 The subroutine name; C<(eval)> if an C<eval>().
3872 1 if it has arguments, 0 if not
3874 =item * C<$wantarray>
3876 1 if array context, 0 if scalar context
3878 =item * C<$evaltext>
3880 The C<eval>() text, if any (undefined for C<eval BLOCK>)
3882 =item * C<$is_require>
3884 frame was created by a C<use> or C<require> statement
3888 pragma information; subject to change between versions
3892 pragma information; subject to change between versions
3894 =item * C<@DB::args>
3896 arguments with which the subroutine was invoked
3904 # We need to fully qualify the name ("DB::sub") to make "use strict;"
3905 # happy. -- Shlomi Fish
3907 # Do not use a regex in this subroutine -> results in corrupted memory
3908 # See: [perl #66110]
3910 # lock ourselves under threads
3913 # Whether or not the autoloader was running, a scalar to put the
3914 # sub's return value in (if needed), and an array to put the sub's
3915 # return value in (if needed).
3916 my ( $al, $ret, @ret ) = "";
3917 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
3918 print "creating new thread\n";
3921 # If the last ten characters are '::AUTOLOAD', note we've traced
3922 # into AUTOLOAD for $sub.
3923 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3925 $al = " for $$sub" if defined $$sub;
3928 # We stack the stack pointer and then increment it to protect us
3929 # from a situation that might unwind a whole bunch of call frames
3930 # at once. Localizing the stack pointer means that it will automatically
3931 # unwind the same amount when multiple stack frames are unwound.
3932 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3935 $#stack = $stack_depth;
3937 # Save current single-step setting.
3938 $stack[-1] = $single;
3940 # Turn off all flags except single-stepping.
3943 # If we've gotten really deeply recursed, turn on the flag that will
3944 # make us stop with the 'deep recursion' message.
3945 $single |= 4 if $stack_depth == $deep;
3947 # If frame messages are on ...
3949 $frame & 4 # Extended frame entry message
3951 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3953 # Why -1? But it works! :-(
3954 # Because print_trace will call add 1 to it and then call
3955 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3957 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3959 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3961 # standard frame entry message
3965 # Determine the sub's return type, and capture appropriately.
3968 # Called in array context. call sub and capture output.
3969 # DB::DB will recursively get control again if appropriate; we'll come
3970 # back here when the sub is finished.
3976 # Pop the single-step value back off the stack.
3977 $single |= $stack[ $stack_depth-- ];
3979 # Check for exit trace messages...
3981 $frame & 4 # Extended exit message
3983 print_lineinfo( ' ' x $stack_depth, "out " ),
3984 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3986 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3988 # Standard exit message
3992 # Print the return info if we need to.
3993 if ( $doret eq $stack_depth or $frame & 16 ) {
3995 # Turn off output record separator.
3997 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3999 # Indent if we're printing because of $frame tracing.
4000 print $fh ' ' x $stack_depth if $frame & 16;
4002 # Print the return value.
4003 print $fh "list context return from $sub:\n";
4004 dumpit( $fh, \@ret );
4006 # And don't print it again.
4008 } ## end if ($doret eq $stack_depth...
4009 # And we have to return the return value now.
4011 } ## end if (wantarray)
4015 if ( defined wantarray ) {
4017 # Save the value if it's wanted at all.
4022 # Void return, explicitly.
4027 # Pop the single-step value off the stack.
4028 $single |= $stack[ $stack_depth-- ];
4030 # If we're doing exit messages...
4032 $frame & 4 # Extended messages
4034 print_lineinfo( ' ' x $stack_depth, "out " ),
4035 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
4037 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
4043 # If we are supposed to show the return value... same as before.
4044 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
4046 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4047 print $fh ( ' ' x $stack_depth ) if $frame & 16;
4050 ? "scalar context return from $sub: "
4051 : "void context return from $sub\n"
4053 dumpit( $fh, $ret ) if defined wantarray;
4055 } ## end if ($doret eq $stack_depth...
4057 # Return the appropriate scalar value.
4059 } ## end else [ if (wantarray)
4066 # lock ourselves under threads
4069 # Whether or not the autoloader was running, a scalar to put the
4070 # sub's return value in (if needed), and an array to put the sub's
4071 # return value in (if needed).
4072 my ( $al, $ret, @ret ) = "";
4073 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
4074 print "creating new thread\n";
4077 # If the last ten characters are C'::AUTOLOAD', note we've traced
4078 # into AUTOLOAD for $sub.
4079 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
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 $frame & 4 # Extended frame entry message
4106 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
4108 # Why -1? But it works! :-(
4109 # Because print_trace will call add 1 to it and then call
4110 # dump_trace; this results in our skipping -1+1 = 0 stack frames
4112 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
4114 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
4116 # standard frame entry message
4120 # Pop the single-step value back off the stack.
4121 $single |= $stack[ $stack_depth-- ];
4123 # call the original lvalue sub.
4127 # Abstracting common code from multiple places elsewhere:
4128 sub depth_print_lineinfo {
4129 my $always_print = shift;
4131 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth);
4134 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
4136 In Perl 5.8.0, there was a major realignment of the commands and what they did,
4137 Most of the changes were to systematize the command structure and to eliminate
4138 commands that threw away user input without checking.
4140 The following sections describe the code added to make it easy to support
4141 multiple command sets with conflicting command names. This section is a start
4142 at unifying all command processing to make it simpler to develop commands.
4144 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
4145 number, and C<$dbline> (the current line) as arguments.
4147 Support functions in this section which have multiple modes of failure C<die>
4148 on error; the rest simply return a false value.
4150 The user-interface functions (all of the C<cmd_*> functions) just output
4155 The C<%set> hash defines the mapping from command letter to subroutine
4158 C<%set> is a two-level hash, indexed by set name and then by command name.
4159 Note that trying to set the CommandSet to C<foobar> simply results in the
4160 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
4169 'A' => 'pre580_null',
4171 'B' => 'pre580_null',
4172 'd' => 'pre580_null',
4175 'M' => 'pre580_null',
4177 'o' => 'pre580_null',
4183 '<' => 'pre590_prepost',
4184 '<<' => 'pre590_prepost',
4185 '>' => 'pre590_prepost',
4186 '>>' => 'pre590_prepost',
4187 '{' => 'pre590_prepost',
4188 '{{' => 'pre590_prepost',
4192 my %breakpoints_data;
4194 sub _has_breakpoint_data_ref {
4195 my ($filename, $line) = @_;
4198 exists( $breakpoints_data{$filename} )
4200 exists( $breakpoints_data{$filename}{$line} )
4204 sub _get_breakpoint_data_ref {
4205 my ($filename, $line) = @_;
4207 return ($breakpoints_data{$filename}{$line} ||= +{});
4210 sub _delete_breakpoint_data_ref {
4211 my ($filename, $line) = @_;
4213 delete($breakpoints_data{$filename}{$line});
4214 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) {
4215 delete($breakpoints_data{$filename});
4221 sub _set_breakpoint_enabled_status {
4222 my ($filename, $line, $status) = @_;
4224 _get_breakpoint_data_ref($filename, $line)->{'enabled'} =
4231 sub _enable_breakpoint_temp_enabled_status {
4232 my ($filename, $line) = @_;
4234 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1;
4239 sub _cancel_breakpoint_temp_enabled_status {
4240 my ($filename, $line) = @_;
4242 my $ref = _get_breakpoint_data_ref($filename, $line);
4244 delete ($ref->{'temp_enabled'});
4247 _delete_breakpoint_data_ref($filename, $line);
4253 sub _is_breakpoint_enabled {
4254 my ($filename, $line) = @_;
4256 my $data_ref = _get_breakpoint_data_ref($filename, $line);
4257 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'});
4260 =head2 C<cmd_wrapper()> (API)
4262 C<cmd_wrapper()> allows the debugger to switch command sets
4263 depending on the value of the C<CommandSet> option.
4265 It tries to look up the command in the C<%set> package-level I<lexical>
4266 (which means external entities can't fiddle with it) and create the name of
4267 the sub to call based on the value found in the hash (if it's there). I<All>
4268 of the commands to be handled in a set have to be added to C<%set>; if they
4269 aren't found, the 5.8.0 equivalent is called (if there is one).
4271 This code uses symbolic references.
4278 my $dblineno = shift;
4280 # Assemble the command subroutine's name by looking up the
4281 # command set and command name in %set. If we can't find it,
4282 # default to the older version of the command.
4284 . ( $set{$CommandSet}{$cmd}
4285 || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) );
4287 # Call the command subroutine, call it by name.
4288 return __PACKAGE__->can($call)->( $cmd, $line, $dblineno );
4289 } ## end sub cmd_wrapper
4291 =head3 C<cmd_a> (command)
4293 The C<a> command handles pre-execution actions. These are associated with a
4294 particular line, so they're stored in C<%dbline>. We default to the current
4295 line if none is specified.
4301 my $line = shift || ''; # [.|line] expr
4304 # If it's dot (here), or not all digits, use the current line.
4305 $line =~ s/\A\./$dbline/;
4307 # Should be a line number followed by an expression.
4308 if ( my ($lineno, $expr) = $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
4310 if (! length($lineno)) {
4314 # If we have an expression ...
4315 if ( length $expr ) {
4317 # ... but the line isn't breakable, complain.
4318 if ( $dbline[$lineno] == 0 ) {
4320 "Line $lineno($dbline[$lineno]) does not have an action?\n";
4324 # It's executable. Record that the line has an action.
4325 $had_breakpoints{$filename} |= 2;
4327 # Remove any action, temp breakpoint, etc.
4328 $dbline{$lineno} =~ s/\0[^\0]*//;
4330 # Add the action to the line.
4331 $dbline{$lineno} .= "\0" . action($expr);
4333 _set_breakpoint_enabled_status($filename, $lineno, 1);
4335 } ## end if (length $expr)
4336 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
4341 "Adding an action requires an optional lineno and an expression\n"
4346 =head3 C<cmd_A> (command)
4348 Delete actions. Similar to above, except the delete code is in a separate
4349 subroutine, C<delete_action>.
4355 my $line = shift || '';
4359 $line =~ s/^\./$dbline/;
4361 # Call delete_action with a null param to delete them all.
4362 # The '1' forces the eval to be true. It'll be false only
4363 # if delete_action blows up for some reason, in which case
4364 # we print $@ and get out.
4365 if ( $line eq '*' ) {
4366 if (! eval { _delete_all_actions(); 1 }) {
4372 # There's a real line number. Pass it to delete_action.
4373 # Error trapping is as above.
4374 elsif ( $line =~ /^(\S.*)/ ) {
4375 if (! eval { delete_action($1); 1 }) {
4381 # Swing and a miss. Bad syntax.
4384 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4388 =head3 C<delete_action> (API)
4390 C<delete_action> accepts either a line number or C<undef>. If a line number
4391 is specified, we check for the line being executable (if it's not, it
4392 couldn't have had an action). If it is, we just take the action off (this
4393 will get any kind of an action, including breakpoints).
4397 sub _remove_action_from_dbline {
4400 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4401 delete $dbline{$i} if $dbline{$i} eq '';
4406 sub _delete_all_actions {
4407 print {$OUT} "Deleting all actions...\n";
4409 for my $file ( keys %had_breakpoints ) {
4410 local *dbline = $main::{ '_<' . $file };
4413 for my $i (1 .. $max) {
4414 if ( defined $dbline{$i} ) {
4415 _remove_action_from_dbline($i);
4419 unless ( $had_breakpoints{$file} &= ~2 ) {
4420 delete $had_breakpoints{$file};
4430 if ( defined($i) ) {
4432 die "Line $i has no action .\n" if $dbline[$i] == 0;
4434 # Nuke whatever's there.
4435 _remove_action_from_dbline($i);
4438 _delete_all_actions();
4442 =head3 C<cmd_b> (command)
4444 Set breakpoints. Since breakpoints can be set in so many places, in so many
4445 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4446 we try to parse the command type, and then shuttle it off to an appropriate
4447 subroutine to actually do the work of setting the breakpoint in the right
4454 my $line = shift; # [.|line] [cond]
4457 my $default_cond = sub {
4459 return length($cond) ? $cond : '1';
4462 # Make . the current line number if it's there..
4463 $line =~ s/^\.(\s|\z)/$dbline$1/;
4465 # No line number, no condition. Simple break on current line.
4466 if ( $line =~ /^\s*$/ ) {
4467 cmd_b_line( $dbline, 1 );
4470 # Break on load for a file.
4471 elsif ( my ($file) = $line =~ /^load\b\s*(.*)/ ) {
4476 # b compile|postpone <some sub> [<condition>]
4477 # The interpreter actually traps this one for us; we just put the
4478 # necessary condition in the %postponed hash.
4479 elsif ( my ($action, $subname, $cond)
4480 = $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4482 # De-Perl4-ify the name - ' separators to ::.
4483 $subname =~ s/'/::/g;
4485 # Qualify it into the current package unless it's already qualified.
4486 $subname = "${package}::" . $subname unless $subname =~ /::/;
4488 # Add main if it starts with ::.
4489 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4491 # Save the break type for this sub.
4492 $postponed{$subname} = (($action eq 'postpone')
4493 ? ( "break +0 if " . $default_cond->($cond) )
4495 } ## end elsif ($line =~ ...
4496 # b <filename>:<line> [<condition>]
4497 elsif (my ($filename, $line_num, $cond)
4498 = $line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) {
4499 cmd_b_filename_line(
4502 (length($cond) ? $cond : '1'),
4505 # b <sub name> [<condition>]
4506 elsif ( my ($new_subname, $new_cond) =
4507 $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4510 $subname = $new_subname;
4511 cmd_b_sub( $subname, $default_cond->($new_cond) );
4514 # b <line> [<condition>].
4515 elsif ( my ($line_n, $cond) = $line =~ /^(\d*)\s*(.*)/ ) {
4517 # Capture the line. If none, it's the current line.
4518 $line = $line_n || $dbline;
4521 cmd_b_line( $line, $default_cond->($cond) );
4524 # Line didn't make sense.
4526 print "confused by line($line)?\n";
4532 =head3 C<break_on_load> (API)
4534 We want to break when this file is loaded. Mark this file in the
4535 C<%break_on_load> hash, and note that it has a breakpoint in
4536 C<%had_breakpoints>.
4542 $break_on_load{$file} = 1;
4543 $had_breakpoints{$file} |= 1;
4546 =head3 C<report_break_on_load> (API)
4548 Gives us an array of filenames that are set to break on load. Note that
4549 only files with break-on-load are in here, so simply showing the keys
4554 sub report_break_on_load {
4555 sort keys %break_on_load;
4558 =head3 C<cmd_b_load> (command)
4560 We take the file passed in and try to find it in C<%INC> (which maps modules
4561 to files they came from). We mark those files for break-on-load via
4562 C<break_on_load> and then report that it was done.
4570 # This is a block because that way we can use a redo inside it
4571 # even without there being any looping structure at all outside it.
4574 # Save short name and full path if found.
4576 push @files, $::INC{$file} if $::INC{$file};
4578 # Tack on .pm and do it again unless there was a '.' in the name
4580 $file .= '.pm', redo unless $file =~ /\./;
4583 # Do the real work here.
4584 break_on_load($_) for @files;
4586 # All the files that have break-on-load breakpoints.
4587 @files = report_break_on_load;
4589 # Normalize for the purposes of our printing this.
4592 print $OUT "Will stop on load of '@files'.\n";
4593 } ## end sub cmd_b_load
4595 =head3 C<$filename_error> (API package global)
4597 Several of the functions we need to implement in the API need to work both
4598 on the current file and on other files. We don't want to duplicate code, so
4599 C<$filename_error> is used to contain the name of the file that's being
4600 worked on (if it's not the current one).
4602 We can now build functions in pairs: the basic function works on the current
4603 file, and uses C<$filename_error> as part of its error message. Since this is
4604 initialized to C<"">, no filename will appear when we are working on the
4607 The second function is a wrapper which does the following:
4613 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4617 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4621 Calls the first function.
4623 The first function works on the I<current> file (i.e., the one we changed to),
4624 and prints C<$filename_error> in the error message (the name of the other file)
4625 if it needs to. When the functions return, C<*dbline> is restored to point
4626 to the actual current file (the one we're executing in) and
4627 C<$filename_error> is restored to C<"">. This restores everything to
4628 the way it was before the second function was called at all.
4630 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4637 use vars qw($filename_error);
4638 $filename_error = '';
4640 =head3 breakable_line(from, to) (API)
4642 The subroutine decides whether or not a line in the current file is breakable.
4643 It walks through C<@dbline> within the range of lines specified, looking for
4644 the first line that is breakable.
4646 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4647 first line I<after> C<$to> that's breakable, if there is one.
4649 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4650 first line I<before> C<$to> that's breakable, if there is one.
4654 sub breakable_line {
4656 my ( $from, $to ) = @_;
4658 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4661 # If there are at least 2 arguments, we're trying to search a range.
4664 # $delta is positive for a forward search, negative for a backward one.
4665 my $delta = $from < $to ? +1 : -1;
4667 # Keep us from running off the ends of the file.
4668 my $limit = $delta > 0 ? $#dbline : 1;
4670 # Clever test. If you're a mathematician, it's obvious why this
4671 # test works. If not:
4672 # If $delta is positive (going forward), $limit will be $#dbline.
4673 # If $to is less than $limit, ($limit - $to) will be positive, times
4674 # $delta of 1 (positive), so the result is > 0 and we should use $to
4675 # as the stopping point.
4677 # If $to is greater than $limit, ($limit - $to) is negative,
4678 # times $delta of 1 (positive), so the result is < 0 and we should
4679 # use $limit ($#dbline) as the stopping point.
4681 # If $delta is negative (going backward), $limit will be 1.
4682 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4683 # (negative) so the result is > 0, and we use $to as the stopping
4686 # If $to is less than zero, ($limit - $to) will be positive,
4687 # times $delta of -1 (negative), so the result is not > 0, and
4688 # we use $limit (1) as the stopping point.
4690 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4691 # (negative), still giving zero; the result is not > 0, and
4692 # we use $limit (1) as the stopping point.
4694 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4695 # (negative), giving a positive (>0) value, so we'll set $limit to
4698 $limit = $to if ( $limit - $to ) * $delta > 0;
4700 # The real search loop.
4701 # $i starts at $from (the point we want to start searching from).
4702 # We move through @dbline in the appropriate direction (determined
4703 # by $delta: either -1 (back) or +1 (ahead).
4704 # We stay in as long as we haven't hit an executable line
4705 # ($dbline[$i] == 0 means not executable) and we haven't reached
4706 # the limit yet (test similar to the above).
4707 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4709 } ## end if (@_ >= 2)
4711 # If $i points to a line that is executable, return that.
4712 return $i unless $dbline[$i] == 0;
4714 # Format the message and print it: no breakable lines in range.
4715 my ( $pl, $upto ) = ( '', '' );
4716 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4718 # If there's a filename in filename_error, we'll see it.
4720 die "Line$pl $from$upto$filename_error not breakable\n";
4721 } ## end sub breakable_line
4723 =head3 breakable_line_in_filename(file, from, to) (API)
4725 Like C<breakable_line>, but look in another file.
4729 sub breakable_line_in_filename {
4731 # Capture the file name.
4734 # Swap the magic line array over there temporarily.
4735 local *dbline = $main::{ '_<' . $f };
4737 # If there's an error, it's in this other file.
4738 local $filename_error = " of '$f'";
4740 # Find the breakable line.
4743 # *dbline and $filename_error get restored when this block ends.
4745 } ## end sub breakable_line_in_filename
4747 =head3 break_on_line(lineno, [condition]) (API)
4749 Adds a breakpoint with the specified condition (or 1 if no condition was
4750 specified) to the specified line. Dies if it can't.
4756 my $cond = @_ ? shift(@_) : 1;
4762 # Woops, not a breakable line. $filename_error allows us to say
4763 # if it was in a different file.
4764 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4766 # Mark this file as having breakpoints in it.
4767 $had_breakpoints{$filename} |= 1;
4769 # If there is an action or condition here already ...
4770 if ( $dbline{$i} ) {
4772 # ... swap this condition for the existing one.
4773 $dbline{$i} =~ s/^[^\0]*/$cond/;
4777 # Nothing here - just add the condition.
4778 $dbline{$i} = $cond;
4780 _set_breakpoint_enabled_status($filename, $i, 1);
4784 } ## end sub break_on_line
4786 =head3 cmd_b_line(line, [condition]) (command)
4788 Wrapper for C<break_on_line>. Prints the failure message if it
4794 if (not eval { break_on_line(@_); 1 }) {
4796 print $OUT $@ and return;
4800 } ## end sub cmd_b_line
4802 =head3 cmd_b_filename_line(line, [condition]) (command)
4804 Wrapper for C<break_on_filename_line>. Prints the failure message if it
4809 sub cmd_b_filename_line {
4810 if (not eval { break_on_filename_line(@_); 1 }) {
4812 print $OUT $@ and return;
4818 =head3 break_on_filename_line(file, line, [condition]) (API)
4820 Switches to the file specified and then calls C<break_on_line> to set
4825 sub break_on_filename_line {
4828 my $cond = @_ ? shift(@_) : 1;
4830 # Switch the magical hash temporarily.
4831 local *dbline = $main::{ '_<' . $f };
4833 # Localize the variables that break_on_line uses to make its message.
4834 local $filename_error = " of '$f'";
4835 local $filename = $f;
4837 # Add the breakpoint.
4838 break_on_line( $i, $cond );
4841 } ## end sub break_on_filename_line
4843 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4845 Switch to another file, search the range of lines specified for an
4846 executable one, and put a breakpoint on the first one you find.
4850 sub break_on_filename_line_range {
4854 my $cond = @_ ? shift(@_) : 1;
4856 # Find a breakable line if there is one.
4857 my $i = breakable_line_in_filename( $f, $from, $to );
4859 # Add the breakpoint.
4860 break_on_filename_line( $f, $i, $cond );
4863 } ## end sub break_on_filename_line_range
4865 =head3 subroutine_filename_lines(subname, [condition]) (API)
4867 Search for a subroutine within a given file. The condition is ignored.
4868 Uses C<find_sub> to locate the desired subroutine.
4872 sub subroutine_filename_lines {
4873 my ( $subname ) = @_;
4875 # Returned value from find_sub() is fullpathname:startline-endline.
4876 # The match creates the list (fullpathname, start, end).
4877 return (find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/);
4878 } ## end sub subroutine_filename_lines
4880 =head3 break_subroutine(subname) (API)
4882 Places a break on the first line possible in the specified subroutine. Uses
4883 C<subroutine_filename_lines> to find the subroutine, and
4884 C<break_on_filename_line_range> to place the break.
4888 sub break_subroutine {
4889 my $subname = shift;
4891 # Get filename, start, and end.
4892 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
4893 or die "Subroutine $subname not found.\n";
4896 # Null condition changes to '1' (always true).
4897 my $cond = @_ ? shift(@_) : 1;
4899 # Put a break the first place possible in the range of lines
4900 # that make up this subroutine.
4901 break_on_filename_line_range( $file, $s, $e, $cond );
4904 } ## end sub break_subroutine
4906 =head3 cmd_b_sub(subname, [condition]) (command)
4908 We take the incoming subroutine name and fully-qualify it as best we can.
4912 =item 1. If it's already fully-qualified, leave it alone.
4914 =item 2. Try putting it in the current package.
4916 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
4918 =item 4. If it starts with '::', put it in 'main::'.
4922 After all this cleanup, we call C<break_subroutine> to try to set the
4928 my ( $subname, $cond ) = @_;
4930 # Add always-true condition if we have none.
4931 $cond = 1 unless @_ >= 2;
4933 # If the subname isn't a code reference, qualify it so that
4934 # break_subroutine() will work right.
4935 unless ( ref $subname eq 'CODE' ) {
4938 $subname =~ s/\'/::/g;
4941 # Put it in this package unless it's already qualified.
4942 $subname = "${package}::" . $subname
4943 unless $subname =~ /::/;
4945 # Requalify it into CORE::GLOBAL if qualifying it into this
4946 # package resulted in its not being defined, but only do so
4947 # if it really is in CORE::GLOBAL.
4948 $subname = "CORE::GLOBAL::$s"
4949 if not defined &$subname
4951 and defined &{"CORE::GLOBAL::$s"};
4953 # Put it in package 'main' if it has a leading ::.
4954 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4956 } ## end unless (ref $subname eq 'CODE')
4958 # Try to set the breakpoint.
4959 if (not eval { break_subroutine( $subname, $cond ); 1 }) {
4961 print $OUT $@ and return;
4965 } ## end sub cmd_b_sub
4967 =head3 C<cmd_B> - delete breakpoint(s) (command)
4969 The command mostly parses the command line and tries to turn the argument
4970 into a line spec. If it can't, it uses the current line. It then calls
4971 C<delete_breakpoint> to actually do the work.
4973 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
4974 thereby deleting all the breakpoints.
4981 # No line spec? Use dbline.
4982 # If there is one, use it if it's non-zero, or wipe it out if it is.
4983 my $line = ( $_[0] =~ /\A\./ ) ? $dbline : (shift || '');
4986 # If the line was dot, make the line the current one.
4987 $line =~ s/^\./$dbline/;
4989 # If it's * we're deleting all the breakpoints.
4990 if ( $line eq '*' ) {
4991 if (not eval { delete_breakpoint(); 1 }) {
4996 # If there is a line spec, delete the breakpoint on that line.
4997 elsif ( $line =~ /\A(\S.*)/ ) {
4998 if (not eval { delete_breakpoint( $line || $dbline ); 1 }) {
5002 } ## end elsif ($line =~ /^(\S.*)/)
5007 "Deleting a breakpoint requires a line number, or '*' for all\n"
5014 =head3 delete_breakpoint([line]) (API)
5016 This actually does the work of deleting either a single breakpoint, or all
5019 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
5020 just drop out with a message saying so. If it is, we remove the condition
5021 part of the 'condition\0action' that says there's a breakpoint here. If,
5022 after we've done that, there's nothing left, we delete the corresponding
5023 line in C<%dbline> to signal that no action needs to be taken for this line.
5025 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
5026 which lists all currently-loaded files which have breakpoints. We then look
5027 at each line in each of these files, temporarily switching the C<%dbline>
5028 and C<@dbline> structures to point to the files in question, and do what
5029 we did in the single line case: delete the condition in C<@dbline>, and
5030 delete the key in C<%dbline> if nothing's left.
5032 We then wholesale delete C<%postponed>, C<%postponed_file>, and
5033 C<%break_on_load>, because these structures contain breakpoints for files
5034 and code that haven't been loaded yet. We can just kill these off because there
5035 are no magical debugger structures associated with them.
5039 sub _remove_breakpoint_entry {
5043 _delete_breakpoint_data_ref($fn, $i);
5048 sub _delete_all_breakpoints {
5049 print {$OUT} "Deleting all breakpoints...\n";
5051 # %had_breakpoints lists every file that had at least one
5053 for my $fn ( keys %had_breakpoints ) {
5055 # Switch to the desired file temporarily.
5056 local *dbline = $main::{ '_<' . $fn };
5060 # For all lines in this file ...
5061 for my $i (1 .. $max) {
5063 # If there's a breakpoint or action on this line ...
5064 if ( defined $dbline{$i} ) {
5066 # ... remove the breakpoint.
5067 $dbline{$i} =~ s/\A[^\0]+//;
5068 if ( $dbline{$i} =~ s/\A\0?\z// ) {
5069 # Remove the entry altogether if no action is there.
5070 _remove_breakpoint_entry($fn, $i);
5072 } ## end if (defined $dbline{$i...
5073 } ## end for $i (1 .. $max)
5075 # If, after we turn off the "there were breakpoints in this file"
5076 # bit, the entry in %had_breakpoints for this file is zero,
5077 # we should remove this file from the hash.
5078 if ( not $had_breakpoints{$fn} &= (~1) ) {
5079 delete $had_breakpoints{$fn};
5081 } ## end for my $fn (keys %had_breakpoints)
5083 # Kill off all the other breakpoints that are waiting for files that
5084 # haven't been loaded yet.
5086 undef %postponed_file;
5087 undef %break_on_load;
5092 sub _delete_breakpoint_from_line {
5095 # Woops. This line wasn't breakable at all.
5096 die "Line $i not breakable.\n" if $dbline[$i] == 0;
5098 # Kill the condition, but leave any action.
5099 $dbline{$i} =~ s/\A[^\0]*//;
5101 # Remove the entry entirely if there's no action left.
5102 if ($dbline{$i} eq '') {
5103 _remove_breakpoint_entry($filename, $i);
5109 sub delete_breakpoint {
5112 # If we got a line, delete just that one.
5113 if ( defined($i) ) {
5114 _delete_breakpoint_from_line($i);
5116 # No line; delete them all.
5118 _delete_all_breakpoints();
5124 =head3 cmd_stop (command)
5126 This is meant to be part of the new command API, but it isn't called or used
5127 anywhere else in the debugger. XXX It is probably meant for use in development
5132 sub cmd_stop { # As on ^C, but not signal-safy.
5136 =head3 C<cmd_e> - threads
5138 Display the current thread id:
5142 This could be how (when implemented) to send commands to this thread id (e cmd)
5143 or that thread id (e tid cmd).
5150 unless (exists($INC{'threads.pm'})) {
5151 print "threads not loaded($ENV{PERL5DB_THREADED})
5152 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5154 my $tid = threads->tid;
5155 print "thread id: $tid\n";
5159 =head3 C<cmd_E> - list of thread ids
5161 Display the list of available thread ids:
5165 This could be used (when implemented) to send commands to all threads (E cmd).
5172 unless (exists($INC{'threads.pm'})) {
5173 print "threads not loaded($ENV{PERL5DB_THREADED})
5174 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5176 my $tid = threads->tid;
5177 print "thread ids: ".join(', ',
5178 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
5183 =head3 C<cmd_h> - help command (command)
5185 Does the work of either
5191 Showing all the debugger help
5195 Showing help for a specific command
5202 use vars qw($summary);
5207 # If we have no operand, assume null.
5208 my $line = shift || '';
5210 # 'h h'. Print the long-format help.
5211 if ( $line =~ /\Ah\s*\z/ ) {
5215 # 'h <something>'. Search for the command and print only its help.
5216 elsif ( my ($asked) = $line =~ /\A(\S.*)\z/ ) {
5218 # support long commands; otherwise bogus errors
5219 # happen when you ask for h on <CR> for example
5220 my $qasked = quotemeta($asked); # for searching; we don't
5221 # want to use it as a pattern.
5222 # XXX: finds CR but not <CR>
5224 # Search the help string for the command.
5226 $help =~ /^ # Start of a line
5228 (?:[IB]<) # Optional markup
5229 $qasked # The requested command
5234 # It's there; pull it out and print it.
5238 (?:[IB]<) # Optional markup
5239 $qasked # The command
5240 ([\s\S]*?) # Description line(s)
5241 \n) # End of last description line
5242 (?!\s) # Next line not starting with
5251 # Not found; not a debugger command.
5253 print_help("B<$asked> is not a debugger command.\n");
5255 } ## end elsif ($line =~ /^(\S.*)$/)
5257 # 'h' - print the summary help.
5259 print_help($summary);
5263 =head3 C<cmd_i> - inheritance display
5265 Display the (nested) parentage of the module or object given.
5272 foreach my $isa ( split( /\s+/, $line ) ) {
5274 ($isa) = DB::eval();
5281 defined( ${"$_\::VERSION"} )
5282 ? ' ' . ${"$_\::VERSION"}
5284 } @{mro::get_linear_isa(ref($isa) || $isa)}
5290 =head3 C<cmd_l> - list lines (command)
5292 Most of the command is taken up with transforming all the different line
5293 specification syntaxes into 'start-stop'. After that is done, the command
5294 runs a loop over C<@dbline> for the specified range of lines. It handles
5295 the printing of each line and any markers (C<==E<gt>> for current line,
5296 C<b> for break on this line, C<a> for action on this line, C<:> for this
5299 We save the last line listed in the C<$start> global for further listing
5305 my $current_line = $line;
5309 # If this is '-something', delete any spaces after the dash.
5310 $line =~ s/^-\s*$/-/;
5312 # If the line is '$something', assume this is a scalar containing a
5314 if ( $line =~ /^(\$.*)/s ) {
5316 # Set up for DB::eval() - evaluate in *user* context.
5319 my ($s) = DB::eval();
5321 # Ooops. Bad scalar.
5323 print {$OUT} "Error: $@\n";
5327 # Good scalar. If it's a reference, find what it points to.
5329 print {$OUT} "Interpreted as: $1 $s\n";
5332 # Call self recursively to really do the command.
5334 } ## end if ($line =~ /^(\$.*)/s)
5336 # l name. Try to find a sub by that name.
5337 elsif ( ($subname) = $line =~ /\A([\':A-Za-z_][\':\w]*(?:\[.*\])?)/s ) {
5341 $subname =~ s/\'/::/;
5343 # Put it in this package unless it starts with ::.
5344 $subname = $package . "::" . $subname unless $subname =~ /::/;
5346 # Put it in CORE::GLOBAL if t doesn't start with :: and
5347 # it doesn't live in this package and it lives in CORE::GLOBAL.
5348 $subname = "CORE::GLOBAL::$s"
5349 if not defined &$subname
5351 and defined &{"CORE::GLOBAL::$s"};
5353 # Put leading '::' names into 'main::'.
5354 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
5356 # Get name:start-stop from find_sub, and break this up at
5358 my @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
5360 # Pull off start-stop.
5361 my $subrange = pop @pieces;
5363 # If the name contained colons, the split broke it up.
5364 # Put it back together.
5365 $file = join( ':', @pieces );
5367 # If we're not in that file, switch over to it.
5368 if ( $file ne $filename ) {
5369 print $OUT "Switching to file '$file'.\n"
5370 unless $slave_editor;
5372 # Switch debugger's magic structures.
5373 *dbline = $main::{ '_<' . $file };
5376 } ## end if ($file ne $filename)
5378 # Subrange is 'start-stop'. If this is less than a window full,
5379 # swap it to 'start+', which will list a window from the start point.
5381 if ( eval($subrange) < -$window ) {
5382 $subrange =~ s/-.*/+/;
5385 # Call self recursively to list the range.
5387 cmd_l( 'l', $subrange );
5388 } ## end if ($subrange)
5392 print $OUT "Subroutine $subname not found.\n";
5394 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
5397 elsif ( $line !~ /\S/ ) {
5399 # Compute new range to list.
5400 $incr = $window - 1;
5401 $line = $start . '-' . ( $start + $incr );
5404 cmd_l( 'l', $line );
5407 # l [start]+number_of_lines
5408 elsif ( my ($new_start, $new_incr) = $line =~ /\A(\d*)\+(\d*)\z/ ) {
5410 # Don't reset start for 'l +nnn'.
5411 $start = $new_start if $new_start;
5413 # Increment for list. Use window size if not specified.
5414 # (Allows 'l +' to work.)
5416 $incr = $window - 1 unless $incr;
5418 # Create a line range we'll understand, and recurse to do it.
5419 $line = $start . '-' . ( $start + $incr );
5420 cmd_l( 'l', $line );
5421 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
5423 # l start-stop or l start,stop
5424 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) {
5426 # Determine end point; use end of file if not specified.
5427 my $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 );
5429 # Go on to the end, and then stop.
5430 $end = $max if $end > $max;
5432 # Determine start line.
5434 $i = $line if $i eq '.';
5438 # If we're running under a slave editor, force it to show the lines.
5439 if ($slave_editor) {
5440 print $OUT "\032\032$filename:$i:0\n";
5444 # We're doing it ourselves. We want to show the line and special
5446 # - the current line in execution
5447 # - whether a line is breakable or not
5448 # - whether a line has a break or not
5449 # - whether a line has an action or not
5451 for ( ; $i <= $end ; $i++ ) {
5453 # Check for breakpoints and actions.
5454 my ( $stop, $action );
5455 ( $stop, $action ) = split( /\0/, $dbline{$i} )
5458 # ==> if this is the current line in execution,
5459 # : if it's breakable.
5461 ( $i == $current_line and $filename eq $filename_ini )
5463 : ( $dbline[$i] + 0 ? ':' : ' ' );
5465 # Add break and action indicators.
5466 $arrow .= 'b' if $stop;
5467 $arrow .= 'a' if $action;
5470 print $OUT "$i$arrow\t", $dbline[$i];
5472 # Move on to the next line. Drop out on an interrupt.
5473 $i++, last if $signal;
5474 } ## end for (; $i <= $end ; $i++)
5476 # Line the prompt up; print a newline if the last line listed
5477 # didn't have a newline.
5478 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/;
5479 } ## end else [ if ($slave_editor)
5481 # Save the point we last listed to in case another relative 'l'
5482 # command is desired. Don't let it run off the end.
5484 $start = $max if $start > $max;
5485 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
5488 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5490 To list breakpoints, the command has to look determine where all of them are
5491 first. It starts a C<%had_breakpoints>, which tells us what all files have
5492 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5493 magic source and breakpoint data structures) to the file, and then look
5494 through C<%dbline> for lines with breakpoints and/or actions, listing them
5495 out. We look through C<%postponed> not-yet-compiled subroutines that have
5496 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5497 that have breakpoints.
5499 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5506 # If no argument, list everything. Pre-5.8.0 version always lists
5508 my $arg = shift || 'abw';
5509 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
5511 # See what is wanted.
5512 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0;
5513 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0;
5514 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0;
5516 # Breaks and actions are found together, so we look in the same place
5518 if ( $break_wanted or $action_wanted ) {
5520 # Look in all the files with breakpoints...
5521 for my $file ( keys %had_breakpoints ) {
5523 # Temporary switch to this file.
5524 local *dbline = $main::{ '_<' . $file };
5526 # Set up to look through the whole file.
5528 my $was; # Flag: did we print something
5531 # For each line in the file ...
5532 for my $i (1 .. $max) {
5534 # We've got something on this line.
5535 if ( defined $dbline{$i} ) {
5537 # Print the header if we haven't.
5538 print $OUT "$file:\n" unless $was++;
5541 print $OUT " $i:\t", $dbline[$i];
5543 # Pull out the condition and the action.
5544 my ( $stop, $action ) = split( /\0/, $dbline{$i} );
5546 # Print the break if there is one and it's wanted.
5547 print $OUT " break if (", $stop, ")\n"
5551 # Print the action if there is one and it's wanted.
5552 print $OUT " action: ", $action, "\n"
5556 # Quit if the user hit interrupt.
5558 } ## end if (defined $dbline{$i...
5559 } ## end for my $i (1 .. $max)
5560 } ## end for my $file (keys %had_breakpoints)
5561 } ## end if ($break_wanted or $action_wanted)
5563 # Look for breaks in not-yet-compiled subs:
5564 if ( %postponed and $break_wanted ) {
5565 print $OUT "Postponed breakpoints in subroutines:\n";
5567 for $subname ( keys %postponed ) {
5568 print $OUT " $subname\t$postponed{$subname}\n";
5571 } ## end if (%postponed and $break_wanted)
5573 # Find files that have not-yet-loaded breaks:
5574 my @have = map { # Combined keys
5575 keys %{ $postponed_file{$_} }
5576 } keys %postponed_file;
5578 # If there are any, list them.
5579 if ( @have and ( $break_wanted or $action_wanted ) ) {
5580 print $OUT "Postponed breakpoints in files:\n";
5581 for my $file ( keys %postponed_file ) {
5582 my $db = $postponed_file{$file};
5583 print $OUT " $file:\n";
5584 for my $line ( sort { $a <=> $b } keys %$db ) {
5585 print $OUT " $line:\n";
5586 my ( $stop, $action ) = split( /\0/, $$db{$line} );
5587 print $OUT " break if (", $stop, ")\n"
5590 print $OUT " action: ", $action, "\n"
5594 } ## end for $line (sort { $a <=>...
5596 } ## end for $file (keys %postponed_file)
5597 } ## end if (@have and ($break_wanted...
5598 if ( %break_on_load and $break_wanted ) {
5599 print {$OUT} "Breakpoints on load:\n";
5600 BREAK_ON_LOAD: for my $filename ( keys %break_on_load ) {
5601 print {$OUT} " $filename\n";
5602 last BREAK_ON_LOAD if $signal;
5604 } ## end if (%break_on_load and...
5605 if ($watch_wanted and ( $trace & 2 )) {
5606 print {$OUT} "Watch-expressions:\n" if @to_watch;
5607 TO_WATCH: for my $expr (@to_watch) {
5608 print {$OUT} " $expr\n";
5609 last TO_WATCH if $signal;
5614 =head3 C<cmd_M> - list modules (command)
5616 Just call C<list_modules>.
5626 =head3 C<cmd_o> - options (command)
5628 If this is just C<o> by itself, we list the current settings via
5629 C<dump_option>. If there's a nonblank value following it, we pass that on to
5630 C<parse_options> for processing.
5636 my $opt = shift || ''; # opt[=val]
5638 # Nonblank. Try to parse and process.
5639 if ( $opt =~ /^(\S.*)/ ) {
5643 # Blank. List the current option settings.
5651 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5653 Advises the user that the O command has been renamed.
5658 print $OUT "The old O command is now the o command.\n"; # hint
5659 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5660 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5663 =head3 C<cmd_v> - view window (command)
5665 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5666 move back a few lines to list the selected line in context. Uses C<cmd_l>
5667 to do the actual listing after figuring out the range of line to request.
5671 use vars qw($preview);
5677 # Extract the line to list around. (Astute readers will have noted that
5678 # this pattern will match whether or not a numeric line is specified,
5679 # which means that we'll always enter this loop (though a non-numeric
5680 # argument results in no action at all)).
5681 if ( $line =~ /^(\d*)$/ ) {
5683 # Total number of lines to list (a windowful).
5684 $incr = $window - 1;
5686 # Set the start to the argument given (if there was one).
5689 # Back up by the context amount.
5692 # Put together a linespec that cmd_l will like.
5693 $line = $start . '-' . ( $start + $incr );
5696 cmd_l( 'l', $line );
5697 } ## end if ($line =~ /^(\d*)$/)
5700 =head3 C<cmd_w> - add a watch expression (command)
5702 The 5.8 version of this command adds a watch expression if one is specified;
5703 it does nothing if entered with no operands.
5705 We extract the expression, save it, evaluate it in the user's context, and
5706 save the value. We'll re-evaluate it each time the debugger passes a line,
5707 and will stop (see the code at the top of the command loop) if the value
5708 of any of the expressions changes.
5712 sub _add_watch_expr {
5716 push @to_watch, $expr;
5718 # Parameterize DB::eval and call it to get the expression's value
5719 # in the user's context. This version can handle expressions which
5720 # return a list value.
5722 my ($val) = join( ' ', DB::eval() );
5723 $val = ( defined $val ) ? "'$val'" : 'undef';
5725 # Save the current value of the expression.
5726 push @old_watch, $val;
5728 # We are now watching expressions.
5737 # Null expression if no arguments.
5738 my $expr = shift || '';
5740 # If expression is not null ...
5741 if ( $expr =~ /\A\S/ ) {
5742 _add_watch_expr($expr);
5743 } ## end if ($expr =~ /^(\S.*)/)
5745 # You have to give one to get one.
5747 print $OUT "Adding a watch-expression requires an expression\n"; # hint
5753 =head3 C<cmd_W> - delete watch expressions (command)
5755 This command accepts either a watch expression to be removed from the list
5756 of watch expressions, or C<*> to delete them all.
5758 If C<*> is specified, we simply empty the watch expression list and the
5759 watch expression value list. We also turn off the bit that says we've got
5762 If an expression (or partial expression) is specified, we pattern-match
5763 through the expressions and remove the ones that match. We also discard
5764 the corresponding values. If no watch expressions are left, we turn off
5765 the I<watching expressions> bit.
5771 my $expr = shift || '';
5774 if ( $expr eq '*' ) {
5779 print $OUT "Deleting all watch expressions ...\n";
5782 @to_watch = @old_watch = ();
5785 # Delete one of them.
5786 elsif ( $expr =~ /^(\S.*)/ ) {
5788 # Where we are in the list.
5791 # For each expression ...
5792 foreach (@to_watch) {
5793 my $val = $to_watch[$i_cnt];
5795 # Does this one match the command argument?
5796 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
5797 # Yes. Turn it off, and its value too.
5798 splice( @to_watch, $i_cnt, 1 );
5799 splice( @old_watch, $i_cnt, 1 );
5802 } ## end foreach (@to_watch)
5804 # We don't bother to turn watching off because
5805 # a) we don't want to stop calling watchfunction() it it exists
5806 # b) foreach over a null list doesn't do anything anyway
5808 } ## end elsif ($expr =~ /^(\S.*)/)
5810 # No command arguments entered.
5813 "Deleting a watch-expression requires an expression, or '*' for all\n"
5818 ### END of the API section
5820 =head1 SUPPORT ROUTINES
5822 These are general support routines that are used in a number of places
5823 throughout the debugger.
5827 save() saves the user's versions of globals that would mess us up in C<@saved>,
5828 and installs the versions we like better.
5834 # Save eval failure, command failure, extended OS error, output field
5835 # separator, input record separator, output record separator and
5836 # the warning setting.
5837 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
5839 $, = ""; # output field separator is null string
5840 $/ = "\n"; # input record separator is newline
5841 $\ = ""; # output record separator is null string
5842 $^W = 0; # warnings are off
5845 =head2 C<print_lineinfo> - show where we are now
5847 print_lineinfo prints whatever it is that it is handed; it prints it to the
5848 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5849 us to feed line information to a slave editor without messing up the
5854 sub print_lineinfo {
5856 # Make the terminal sensible if we're not the primary debugger.
5857 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5861 } ## end sub print_lineinfo
5863 =head2 C<postponed_sub>
5865 Handles setting postponed breakpoints in subroutines once they're compiled.
5866 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5867 range for the subroutine, then mark the file as having a breakpoint,
5868 temporarily switch the C<*dbline> glob over to the source file, and then
5869 search the given range of lines to find a breakable line. If we find one,
5870 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
5874 # The following takes its argument via $evalarg to preserve current @_
5878 # Get the subroutine name.
5879 my $subname = shift;
5881 # If this is a 'break +<n> if <condition>' ...
5882 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
5884 # If there's no offset, use '+0'.
5885 my $offset = $1 || 0;
5887 # find_sub's value is 'fullpath-filename:start-stop'. It's
5888 # possible that the filename might have colons in it too.
5889 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
5892 # We got the start line. Add the offset '+<n>' from
5893 # $postponed{subname}.
5896 # Switch to the file this sub is in, temporarily.
5897 local *dbline = $main::{ '_<' . $file };
5899 # No warnings, please.
5900 local $^W = 0; # != 0 is magical below
5902 # This file's got a breakpoint in it.
5903 $had_breakpoints{$file} |= 1;
5905 # Last line in file.
5908 # Search forward until we hit a breakable line or get to
5909 # the end of the file.
5910 ++$i until $dbline[$i] != 0 or $i >= $max;
5912 # Copy the breakpoint in and delete it from %postponed.
5913 $dbline{$i} = delete $postponed{$subname};
5916 # find_sub didn't find the sub.
5919 print $OUT "Subroutine $subname not found.\n";
5922 } ## end if ($postponed{$subname...
5923 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
5925 #print $OUT "In postponed_sub for '$subname'.\n";
5926 } ## end sub postponed_sub
5930 Called after each required file is compiled, but before it is executed;
5931 also called if the name of a just-compiled subroutine is a key of
5932 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
5933 etc.) into the just-compiled code.
5935 If this is a C<require>'d file, the incoming parameter is the glob
5936 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
5938 If it's a subroutine, the incoming parameter is the subroutine name.
5944 # If there's a break, process it.
5945 if ($ImmediateStop) {
5947 # Right, we've stopped. Turn it off.
5950 # Enter the command loop when DB::DB gets called.
5954 # If this is a subroutine, let postponed_sub() deal with it.
5955 return &postponed_sub unless ref \$_[0] eq 'GLOB';
5957 # Not a subroutine. Deal with the file.
5958 local *dbline = shift;
5959 my $filename = $dbline;
5960 $filename =~ s/^_<//;
5962 $signal = 1, print $OUT "'$filename' loaded...\n"
5963 if $break_on_load{$filename};
5964 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
5966 # Do we have any breakpoints to put in this file?
5967 return unless $postponed_file{$filename};
5969 # Yes. Mark this file as having breakpoints.
5970 $had_breakpoints{$filename} |= 1;
5972 # "Cannot be done: insufficient magic" - we can't just put the
5973 # breakpoints saved in %postponed_file into %dbline by assigning
5974 # the whole hash; we have to do it one item at a time for the
5975 # breakpoints to be set properly.
5976 #%dbline = %{$postponed_file{$filename}};
5978 # Set the breakpoints, one at a time.
5981 for $key ( keys %{ $postponed_file{$filename} } ) {
5983 # Stash the saved breakpoint into the current file's magic line array.
5984 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
5987 # This file's been compiled; discard the stored breakpoints.
5988 delete $postponed_file{$filename};
5990 } ## end sub postponed
5994 C<dumpit> is the debugger's wrapper around dumpvar.pl.
5996 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
5997 a reference to a variable (the thing to be dumped) as its input.
5999 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
6000 the currently-selected filehandle, thank you very much). The current
6001 values of the package globals C<$single> and C<$trace> are backed up in
6002 lexicals, and they are turned off (this keeps the debugger from trying
6003 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
6004 preserve its current value and it is set to zero to prevent entry/exit
6005 messages from printing, and C<$doret> is localized as well and set to -2 to
6006 prevent return values from being shown.
6008 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
6009 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
6010 installed version in C<@INC>, yours will be used instead. Possible security
6013 It then checks to see if the subroutine C<main::dumpValue> is now defined
6014 it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
6015 localizes the globals necessary for things to be sane when C<main::dumpValue()>
6016 is called, and picks up the variable to be dumped from the parameter list.
6018 It checks the package global C<%options> to see if there's a C<dumpDepth>
6019 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
6020 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
6021 structure: -1 means dump everything.
6023 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
6026 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
6027 and we then return to the caller.
6033 # Save the current output filehandle and switch to the one
6034 # passed in as the first parameter.
6035 my $savout = select(shift);
6037 # Save current settings of $single and $trace, and then turn them off.
6038 my $osingle = $single;
6039 my $otrace = $trace;
6040 $single = $trace = 0;
6042 # XXX Okay, what do $frame and $doret do, again?
6046 # Load dumpvar.pl unless we've already got the sub we need from it.
6047 unless ( defined &main::dumpValue ) {
6048 do 'dumpvar.pl' or die $@;
6051 # If the load succeeded (or we already had dumpvalue()), go ahead
6053 if ( defined &main::dumpValue ) {
6058 my $maxdepth = shift || $option{dumpDepth};
6059 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
6060 &main::dumpValue( $v, $maxdepth );
6061 } ## end if (defined &main::dumpValue)
6063 # Oops, couldn't load dumpvar.pl.
6066 print $OUT "dumpvar.pl not available.\n";
6069 # Reset $single and $trace to their old values.
6073 # Restore the old filehandle.
6077 =head2 C<print_trace>
6079 C<print_trace>'s job is to print a stack trace. It does this via the
6080 C<dump_trace> routine, which actually does all the ferreting-out of the
6081 stack trace data. C<print_trace> takes care of formatting it nicely and
6082 printing it to the proper filehandle.
6090 The filehandle to print to.
6094 How many frames to skip before starting trace.
6098 How many frames to print.
6102 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
6106 The original comment below seems to be noting that the traceback may not be
6107 correct if this routine is called in a tied method.
6111 # Tied method do not create a context, so may get wrong message:
6117 # If this is going to a slave editor, but we're not the primary
6118 # debugger, reset it first.
6120 if $fh eq $LINEINFO # slave editor
6121 and $LINEINFO eq $OUT # normal output
6122 and $term_pid != $$; # not the primary
6124 # Collect the actual trace information to be formatted.
6125 # This is an array of hashes of subroutine call info.
6126 my @sub = dump_trace( $_[0] + 1, $_[1] );
6128 # Grab the "short report" flag from @_.
6129 my $short = $_[2]; # Print short report, next one for sub name
6131 # Run through the traceback info, format it, and print it.
6133 for my $i (0 .. $#sub) {
6135 # Drop out if the user has lost interest and hit control-C.
6138 # Set the separator so arrys print nice.
6141 # Grab and stringify the arguments if they are there.
6143 defined $sub[$i]{args}
6144 ? "(@{ $sub[$i]{args} })"
6147 # Shorten them up if $maxtrace says they're too long.
6148 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
6149 if length $args > $maxtrace;
6151 # Get the file name.
6152 my $file = $sub[$i]{file};
6154 # Put in a filename header if short is off.
6155 $file = $file eq '-e' ? $file : "file '$file'" unless $short;
6157 # Get the actual sub's name, and shorten to $maxtrace's requirement.
6159 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
6161 # Short report uses trimmed file and sub names.
6163 my $sub = @_ >= 4 ? $_[3] : $s;
6164 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
6165 } ## end if ($short)
6167 # Non-short report includes full names.
6169 print $fh "$sub[$i]{context} = $s$args"
6170 . " called from $file"
6171 . " line $sub[$i]{line}\n";
6173 } ## end for my $i (0 .. $#sub)
6174 } ## end sub print_trace
6176 =head2 dump_trace(skip[,count])
6178 Actually collect the traceback information available via C<caller()>. It does
6179 some filtering and cleanup of the data, but mostly it just collects it to
6180 make C<print_trace()>'s job easier.
6182 C<skip> defines the number of stack frames to be skipped, working backwards
6183 from the most current. C<count> determines the total number of frames to
6184 be returned; all of them (well, the first 10^9) are returned if C<count>
6187 This routine returns a list of hashes, from most-recent to least-recent
6188 stack frame. Each has the following keys and values:
6192 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
6194 =item * C<sub> - subroutine name, or C<eval> information
6196 =item * C<args> - undef, or a reference to an array of arguments
6198 =item * C<file> - the file in which this item was defined (if any)
6200 =item * C<line> - the line on which it was defined
6208 # How many levels to skip.
6211 # How many levels to show. (1e9 is a cheap way of saying "all of them";
6212 # it's unlikely that we'll have more than a billion stack frames. If you
6213 # do, you've got an awfully big machine...)
6214 my $count = shift || 1e9;
6216 # We increment skip because caller(1) is the first level *back* from
6217 # the current one. Add $skip to the count of frames so we have a
6218 # simple stop criterion, counting from $skip to $count+$skip.
6222 # These variables are used to capture output from caller();
6223 my ( $p, $file, $line, $sub, $h, $context );
6225 my ( $e, $r, @a, @sub, $args );
6227 # XXX Okay... why'd we do that?
6228 my $nothard = not $frame & 8;
6231 # Do not want to trace this.
6232 my $otrace = $trace;
6235 # Start out at the skip count.
6236 # If we haven't reached the number of frames requested, and caller() is
6237 # still returning something, stay in the loop. (If we pass the requested
6238 # number of stack frames, or we run out - caller() returns nothing - we
6240 # Up the stack frame index to go back one more level each time.
6244 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
6249 # Go through the arguments and save them for later.
6251 for my $arg (@args) {
6253 if ( not defined $arg ) { # undefined parameter
6257 elsif ( $nothard and tied $arg ) { # tied parameter
6260 elsif ( $nothard and $type = ref $arg ) { # reference
6261 push @a, "ref($type)";
6263 else { # can be stringified
6265 "$arg"; # Safe to stringify now - should not call f().
6267 # Backslash any single-quotes or backslashes.
6270 # Single-quote it unless it's a number or a colon-separated
6273 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
6275 # Turn high-bit characters into meta-whatever.
6276 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
6278 # Turn control characters into ^-whatever.
6279 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
6282 } ## end else [ if (not defined $arg)
6283 } ## end for $arg (@args)
6285 # If context is true, this is array (@)context.
6286 # If context is false, this is scalar ($) context.
6287 # If neither, context isn't defined. (This is apparently a 'can't
6289 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
6291 # if the sub has args ($h true), make an anonymous array of the
6293 $args = $h ? [@a] : undef;
6295 # remove trailing newline-whitespace-semicolon-end of line sequence
6296 # from the eval text, if any.
6297 $e =~ s/\n\s*\;\s*\Z// if $e;
6299 # Escape backslashed single-quotes again if necessary.
6300 $e =~ s/([\\\'])/\\$1/g if $e;
6302 # if the require flag is true, the eval text is from a require.
6304 $sub = "require '$e'";
6307 # if it's false, the eval text is really from an eval.
6308 elsif ( defined $r ) {
6312 # If the sub is '(eval)', this is a block eval, meaning we don't
6313 # know what the eval'ed text actually was.
6314 elsif ( $sub eq '(eval)' ) {
6315 $sub = "eval {...}";
6318 # Stick the collected information into @sub as an anonymous hash.
6322 context => $context,
6330 # Stop processing frames if the user hit control-C.
6332 } ## end for ($i = $skip ; $i < ...
6334 # Restore the trace value again.
6337 } ## end sub dump_trace
6341 C<action()> takes input provided as the argument to an add-action command,
6342 either pre- or post-, and makes sure it's a complete command. It doesn't do
6343 any fancy parsing; it just keeps reading input until it gets a string
6344 without a trailing backslash.
6351 while ( $action =~ s/\\$// ) {
6353 # We have a backslash on the end. Read more.
6355 } ## end while ($action =~ s/\\$//)
6357 # Return the assembled action.
6363 This routine mostly just packages up a regular expression to be used
6364 to check that the thing it's being matched against has properly-matched
6367 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
6368 speeds things up by only creating the qr//'ed expression once; if it's
6369 already defined, we don't try to define it again. A speed hack.
6373 use vars qw($balanced_brace_re);
6377 # I hate using globals!
6378 $balanced_brace_re ||= qr{
6381 (?> [^{}] + ) # Non-parens without backtracking
6383 (??{ $balanced_brace_re }) # Group with matching parens
6387 return $_[0] !~ m/$balanced_brace_re/;
6388 } ## end sub unbalanced
6392 C<gets()> is a primitive (very primitive) routine to read continuations.
6393 It was devised for reading continuations for actions.
6394 it just reads more input with C<readline()> and returns it.
6399 &readline("cont: ");
6402 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger
6404 The C<system()> function assumes that it can just go ahead and use STDIN and
6405 STDOUT, but under the debugger, we want it to use the debugger's input and
6408 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes
6409 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
6410 and then puts everything back again.
6416 # We save, change, then restore STDIN and STDOUT to avoid fork() since
6417 # some non-Unix systems can do system() but have problems with fork().
6418 open( SAVEIN, "<&STDIN" ) || &warn("Can't save STDIN");
6419 open( SAVEOUT, ">&STDOUT" ) || &warn("Can't save STDOUT");
6420 open( STDIN, "<&IN" ) || &warn("Can't redirect STDIN");
6421 open( STDOUT, ">&OUT" ) || &warn("Can't redirect STDOUT");
6423 # XXX: using csh or tcsh destroys sigint retvals!
6425 open( STDIN, "<&SAVEIN" ) || &warn("Can't restore STDIN");
6426 open( STDOUT, ">&SAVEOUT" ) || &warn("Can't restore STDOUT");
6430 # most of the $? crud was coping with broken cshisms
6432 &warn( "(Command exited ", ( $? >> 8 ), ")\n" );
6436 "(Command died of SIG#",
6438 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6447 =head1 TTY MANAGEMENT
6449 The subs here do some of the terminal management for multiple debuggers.
6453 Top-level function called when we want to set up a new terminal for use
6456 If the C<noTTY> debugger option was set, we'll either use the terminal
6457 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6458 to find one. If we're a forked debugger, we call C<resetterm> to try to
6459 get a whole new terminal if we can.
6461 In either case, we set up the terminal next. If the C<ReadLine> option was
6462 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6463 the appropriate attributes. We then
6467 use vars qw($ornaments);
6468 use vars qw($rl_attribs);
6472 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6475 require Term::ReadLine;
6477 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6480 my ( $i, $o ) = split $tty, /,/;
6481 $o = $i unless defined $o;
6482 open( IN, "<$i" ) or die "Cannot open TTY '$i' for read: $!";
6483 open( OUT, ">$o" ) or die "Cannot open TTY '$o' for write: $!";
6489 # We don't have a TTY - try to find one via Term::Rendezvous.
6491 require Term::Rendezvous;
6493 # See if we have anything to pass to Term::Rendezvous.
6494 # Use $HOME/.perldbtty$$ if not.
6495 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6497 # Rendezvous and get the filehandles.
6498 my $term_rv = Term::Rendezvous->new( $rv );
6500 $OUT = $term_rv->OUT;
6501 } ## end else [ if ($tty)
6502 } ## end if ($notty)
6504 # We're a daughter debugger. Try to fork off another TTY.
6505 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6509 # If we shouldn't use Term::ReadLine, don't.
6511 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6514 # We're using Term::ReadLine. Get all the attributes for this terminal.
6516 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6518 $rl_attribs = $term->Attribs;
6519 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6520 if defined $rl_attribs->{basic_word_break_characters}
6521 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6522 $rl_attribs->{special_prefixes} = '$@&%';
6523 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6524 $rl_attribs->{completion_function} = \&db_complete;
6525 } ## end else [ if (!$rl)
6527 # Set up the LINEINFO filehandle.
6528 $LINEINFO = $OUT unless defined $LINEINFO;
6529 $lineinfo = $console unless defined $lineinfo;
6535 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6536 $term->SetHistory(@hist);
6539 # XXX Ornaments are turned on unconditionally, which is not
6540 # always a good thing.
6541 ornaments($ornaments) if defined $ornaments;
6543 } ## end sub setterm
6546 $histfile //= option_val("HistFile", undef);
6547 return unless defined $histfile;
6548 open my $fh, "<", $histfile or return;
6559 return unless defined $histfile;
6560 eval { require File::Path } or return;
6561 eval { require File::Basename } or return;
6562 File::Path::mkpath(File::Basename::dirname($histfile));
6563 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6564 $histsize //= option_val("HistSize",100);
6565 my @copy = grep { $_ ne '?' } @hist;
6566 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6567 for ($start .. $#copy) {
6568 print $fh "$copy[$_]\n";
6570 close $fh or die "Could not write '$histfile': $!";
6573 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6575 When the process being debugged forks, or the process invokes a command
6576 via C<system()> which starts a new debugger, we need to be able to get a new
6577 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6578 fight over the terminal, and you can never quite be sure who's going to get the
6579 input you're typing.
6581 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6582 is tasked with doing all the necessary operating system mojo to get a new
6583 TTY (and probably another window) and to direct the new debugger to read and
6586 The debugger provides C<get_fork_TTY> functions which work for TCP
6587 socket servers, X11, OS/2, and Mac OS X. Other systems are not
6588 supported. You are encouraged to write C<get_fork_TTY> functions which
6589 work for I<your> platform and contribute them.
6591 =head3 C<socket_get_fork_TTY>
6595 sub connect_remoteport {
6598 my $socket = IO::Socket::INET->new(
6600 PeerAddr => $remoteport,
6604 die "Unable to connect to remote host: $remoteport\n";
6609 sub socket_get_fork_TTY {
6610 $tty = $LINEINFO = $IN = $OUT = connect_remoteport();
6612 # Do I need to worry about setting $term?
6614 reset_IN_OUT( $IN, $OUT );
6618 =head3 C<xterm_get_fork_TTY>
6620 This function provides the C<get_fork_TTY> function for X11. If a
6621 program running under the debugger forks, a new <xterm> window is opened and
6622 the subsidiary debugger is directed there.
6624 The C<open()> call is of particular note here. We have the new C<xterm>
6625 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6626 command (which prints the device name of the TTY we'll want to use for input
6627 and output to STDOUT, then C<sleep> for a very long time, routing this output
6628 to file number 3. This way we can simply read from the <XT> filehandle (which
6629 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6631 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6636 sub xterm_get_fork_TTY {
6637 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6639 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6642 # Get the output from 'tty' and clean it up a little.
6646 $pidprompt = ''; # Shown anyway in titlebar
6648 # We need $term defined or we can not switch to the newly created xterm
6649 if ($tty ne '' && !defined $term) {
6650 require Term::ReadLine;
6652 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6655 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6658 # There's our new TTY.
6660 } ## end sub xterm_get_fork_TTY
6662 =head3 C<os2_get_fork_TTY>
6664 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6668 # This example function resets $IN, $OUT itself
6670 sub os2_get_fork_TTY { # A simplification of the following (and works without):
6672 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6673 my %opt = ( title => "Daughter Perl debugger $pids $name",
6674 ($rl ? (read_by_key => 1) : ()) );
6675 require OS2::Process;
6676 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
6678 $pidprompt = ''; # Shown anyway in titlebar
6679 reset_IN_OUT($in, $out);
6681 return ''; # Indicate that reset_IN_OUT is called
6682 } ## end sub os2_get_fork_TTY
6684 =head3 C<macosx_get_fork_TTY>
6686 The Mac OS X version uses AppleScript to tell Terminal.app to create
6691 # Notes about Terminal.app's AppleScript support,
6692 # (aka things that might break in future OS versions).
6694 # The "do script" command doesn't return a reference to the new window
6695 # it creates, but since it appears frontmost and windows are enumerated
6696 # front to back, we can use "first window" === "window 1".
6698 # Since "do script" is implemented by supplying the argument (plus a
6699 # return character) as terminal input, there's a potential race condition
6700 # where the debugger could beat the shell to reading the command.
6701 # To prevent this, we wait for the screen to clear before proceeding.
6704 # There's no direct accessor for the tty device name, so we fiddle
6705 # with the window title options until it says what we want.
6708 # There _is_ a direct accessor for the tty device name, _and_ there's
6709 # a new possible component of the window title (the name of the settings
6710 # set). A separate version is needed.
6712 my @script_versions=
6714 ([237, <<'__LEOPARD__'],
6715 tell application "Terminal"
6716 do script "clear;exec sleep 100000"
6717 tell first tab of first window
6719 set custom title to "forked perl debugger"
6720 set title displays custom title to true
6721 repeat while (length of first paragraph of (get contents)) > 0
6729 [100, <<'__JAGUAR_TIGER__'],
6730 tell application "Terminal"
6731 do script "clear;exec sleep 100000"
6733 set title displays shell path to false
6734 set title displays window size to false
6735 set title displays file name to false
6736 set title displays device name to true
6737 set title displays custom title to true
6738 set custom title to ""
6739 copy "/dev/" & name to thetty
6740 set custom title to "forked perl debugger"
6741 repeat while (length of first paragraph of (get contents)) > 0
6751 sub macosx_get_fork_TTY
6753 my($version,$script,$pipe,$tty);
6755 return unless $version=$ENV{TERM_PROGRAM_VERSION};
6756 foreach my $entry (@script_versions) {
6757 if ($version>=$entry->[0]) {
6758 $script=$entry->[1];
6762 return unless defined($script);
6763 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
6764 $tty=readline($pipe);
6766 return unless defined($tty) && $tty =~ m(^/dev/);
6771 =head2 C<create_IN_OUT($flags)>
6773 Create a new pair of filehandles, pointing to a new TTY. If impossible,
6774 try to diagnose why.
6780 =item * 1 - Don't know how to create a new TTY.
6782 =item * 2 - Debugger has forked, but we can't get a new TTY.
6784 =item * 4 - standard debugger startup is happening.
6790 use vars qw($fork_TTY);
6792 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
6794 # If we know how to get a new TTY, do it! $in will have
6795 # the TTY name if get_fork_TTY works.
6796 my $in = &get_fork_TTY if defined &get_fork_TTY;
6798 # It used to be that
6799 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
6801 if ( not defined $in ) {
6804 # We don't know how.
6805 print_help(<<EOP) if $why == 1;
6806 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6810 print_help(<<EOP) if $why == 2;
6811 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6812 This may be an asynchronous session, so the parent debugger may be active.
6815 # Note that both debuggers are fighting over the same input.
6816 print_help(<<EOP) if $why != 4;
6817 Since two debuggers fight for the same TTY, input is severely entangled.
6821 I know how to switch the output to a different window in xterms, OS/2
6822 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
6823 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
6824 B<DB::get_fork_TTY()> returning this.
6826 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6827 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6830 } ## end if (not defined $in)
6831 elsif ( $in ne '' ) {
6835 $console = ''; # Indicate no need to open-from-the-console
6838 } ## end sub create_IN_OUT
6842 Handles rejiggering the prompt when we've forked off a new debugger.
6844 If the new debugger happened because of a C<system()> that invoked a
6845 program under the debugger, the arrow between the old pid and the new
6846 in the prompt has I<two> dashes instead of one.
6848 We take the current list of pids and add this one to the end. If there
6849 isn't any list yet, we make one up out of the initial pid associated with
6850 the terminal and our new pid, sticking an arrow (either one-dashed or
6851 two dashed) in between them.
6853 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6854 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6859 sub resetterm { # We forked, so we need a different TTY
6861 # Needs to be passed to create_IN_OUT() as well.
6864 # resetterm(2): got in here because of a system() starting a debugger.
6865 # resetterm(1): just forked.
6866 my $systemed = $in > 1 ? '-' : '';
6868 # If there's already a list of pids, add this to the end.
6870 $pids =~ s/\]/$systemed->$$]/;
6873 # No pid list. Time to make one.
6875 $pids = "[$term_pid->$$]";
6878 # The prompt we're going to be using for this debugger.
6881 # We now 0wnz this terminal.
6884 # Just return if we're not supposed to try to create a new TTY.
6885 return unless $CreateTTY & $in;
6887 # Try to create a new IN/OUT pair.
6889 } ## end sub resetterm
6893 First, we handle stuff in the typeahead buffer. If there is any, we shift off
6894 the next line, print a message saying we got it, add it to the terminal
6895 history (if possible), and return it.
6897 If there's nothing in the typeahead buffer, check the command filehandle stack.
6898 If there are any filehandles there, read from the last one, and return the line
6899 if we got one. If not, we pop the filehandle off and close it, and try the
6900 next one up the stack.
6902 If we've emptied the filehandle stack, we check to see if we've got a socket
6903 open, and we read that and return it if we do. If we don't, we just call the
6904 core C<readline()> and return its value.
6910 # Localize to prevent it from being smashed in the program being debugged.
6913 # If there are stacked filehandles to read from ...
6914 # (Handle it before the typeahead, because we may call source/etc. from
6918 # Read from the last one in the stack.
6919 my $line = CORE::readline( $cmdfhs[-1] );
6921 # If we got a line ...
6923 ? ( print $OUT ">> $line" and return $line ) # Echo and return
6924 : close pop @cmdfhs; # Pop and close
6925 } ## end while (@cmdfhs)
6927 # Pull a line out of the typeahead if there's stuff there.
6930 # How many lines left.
6931 my $left = @typeahead;
6933 # Get the next line.
6934 my $got = shift @typeahead;
6936 # Print a message saying we got input from the typeahead.
6938 print $OUT "auto(-$left)", shift, $got, "\n";
6940 # Add it to the terminal history (if possible).
6941 $term->AddHistory($got)
6943 and defined $term->Features->{addHistory};
6945 } ## end if (@typeahead)
6947 # We really need to read some input. Turn off entry/exit trace and
6948 # return value printing.
6952 # Nothing on the filehandle stack. Socket?
6953 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
6955 # Send anything we have to send.
6956 $OUT->write( join( '', @_ ) );
6958 # Receive anything there is to receive.
6963 while ($first_time or (length($buf) && ($stuff .= $buf) !~ /\n/))
6966 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
6967 # XXX Don't know. You tell me.
6972 } ## end if (ref $OUT and UNIVERSAL::isa...
6974 # No socket. Just read from the terminal.
6976 return $term->readline(@_);
6978 } ## end sub readline
6980 =head1 OPTIONS SUPPORT ROUTINES
6982 These routines handle listing and setting option values.
6984 =head2 C<dump_option> - list the current value of an option setting
6986 This routine uses C<option_val> to look up the value for an option.
6987 It cleans up escaped single-quotes and then displays the option and
6993 my ( $opt, $val ) = @_;
6994 $val = option_val( $opt, 'N/A' );
6995 $val =~ s/([\\\'])/\\$1/g;
6996 printf $OUT "%20s = '%s'\n", $opt, $val;
6997 } ## end sub dump_option
6999 sub options2remember {
7000 foreach my $k (@RememberOnROptions) {
7001 $option{$k} = option_val( $k, 'N/A' );
7006 =head2 C<option_val> - find the current value of an option
7008 This can't just be a simple hash lookup because of the indirect way that
7009 the option values are stored. Some are retrieved by calling a subroutine,
7010 some are just variables.
7012 You must supply a default value to be used in case the option isn't set.
7017 my ( $opt, $default ) = @_;
7020 # Does this option exist, and is it a variable?
7021 # If so, retrieve the value via the value in %optionVars.
7022 if ( defined $optionVars{$opt}
7023 and defined ${ $optionVars{$opt} } )
7025 $val = ${ $optionVars{$opt} };
7028 # Does this option exist, and it's a subroutine?
7029 # If so, call the subroutine via the ref in %optionAction
7030 # and capture the value.
7031 elsif ( defined $optionAction{$opt}
7032 and defined &{ $optionAction{$opt} } )
7034 $val = &{ $optionAction{$opt} }();
7037 # If there's an action or variable for the supplied option,
7038 # but no value was set, use the default.
7039 elsif (defined $optionAction{$opt} and not defined $option{$opt}
7040 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
7045 # Otherwise, do the simple hash lookup.
7047 $val = $option{$opt};
7050 # If the value isn't defined, use the default.
7051 # Then return whatever the value is.
7052 $val = $default unless defined $val;
7054 } ## end sub option_val
7056 =head2 C<parse_options>
7058 Handles the parsing and execution of option setting/displaying commands.
7060 An option entered by itself is assumed to be I<set me to 1> (the default value)
7061 if the option is a boolean one. If not, the user is prompted to enter a valid
7062 value or to query the current value (via C<option? >).
7064 If C<option=value> is entered, we try to extract a quoted string from the
7065 value (if it is quoted). If it's not, we just use the whole value as-is.
7067 We load any modules required to service this option, and then we set it: if
7068 it just gets stuck in a variable, we do that; if there's a subroutine to
7069 handle setting the option, we call that.
7071 Finally, if we're running in interactive mode, we display the effect of the
7072 user's command back to the terminal, skipping this if we're setting things
7073 during initialization.
7083 # These options need a value. Don't allow them to be clobbered by accident.
7084 my %opt_needs_val = map { ( $_ => 1 ) } qw{
7085 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
7086 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
7089 while (length($s)) {
7092 # Clean off excess leading whitespace.
7093 $s =~ s/^\s+// && next;
7095 # Options are always all word characters, followed by a non-word
7097 if ($s !~ s/^(\w+)(\W?)//) {
7098 print {$OUT} "Invalid option '$s'\n";
7101 my ( $opt, $sep ) = ( $1, $2 );
7103 # Make sure that such an option exists.
7104 my $matches = ( grep { /^\Q$opt/ && ( $option = $_ ) } @options )
7105 || ( grep { /^\Q$opt/i && ( $option = $_ ) } @options );
7108 print {$OUT} "Unknown option '$opt'\n";
7112 print {$OUT} "Ambiguous option '$opt'\n";
7117 # '?' as separator means query, but must have whitespace after it.
7118 if ( "?" eq $sep ) {
7120 print {$OUT} "Option query '$opt?' followed by non-space '$s'\n" ;
7125 #&dump_option($opt);
7126 } ## end if ("?" eq $sep)
7128 # Separator is whitespace (or just a carriage return).
7129 # They're going for a default, which we assume is 1.
7130 elsif ( $sep !~ /\S/ ) {
7132 $val = "1"; # this is an evil default; make 'em set it!
7135 # Separator is =. Trying to set a value.
7136 elsif ( $sep eq "=" ) {
7138 # If quoted, extract a quoted string.
7139 if ($s =~ s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
7141 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
7144 # Not quoted. Use the whole thing. Warn about 'option='.
7148 print OUT qq(Option better cleared using $opt=""\n)
7150 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
7152 } ## end elsif ($sep eq "=")
7154 # "Quoted" with [], <>, or {}.
7155 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
7157 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
7158 $s =~ s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
7159 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last;
7160 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
7161 } ## end else [ if ("?" eq $sep)
7163 # Exclude non-booleans from getting set to 1 by default.
7164 if ( $opt_needs_val{$option} && $val_defaulted ) {
7165 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
7167 "Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n";
7169 } ## end if ($opt_needs_val{$option...
7171 # Save the option value.
7172 $option{$option} = $val if defined $val;
7174 # Load any module that this option requires.
7175 if ( defined($optionRequire{$option}) && defined($val) ) {
7179 require '$optionRequire{$option}';
7181 } || die $@ # XXX: shouldn't happen
7185 # Stick it in the proper variable if it goes in a variable.
7186 if (defined($optionVars{$option}) && defined($val)) {
7187 ${ $optionVars{$option} } = $val;
7190 # Call the appropriate sub if it gets set via sub.
7191 if (defined($optionAction{$option})
7192 && defined (&{ $optionAction{$option} })
7195 &{ $optionAction{$option} }($val);
7198 # Not initialization - echo the value we set it to.
7199 dump_option($option) if ($OUT ne \*STDERR);
7200 } ## end while (length)
7201 } ## end sub parse_options
7203 =head1 RESTART SUPPORT
7205 These routines are used to store (and restore) lists of items in environment
7206 variables during a restart.
7210 Set_list packages up items to be stored in a set of environment variables
7211 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
7212 the values). Values outside the standard ASCII charset are stored by encoding
7213 then as hexadecimal values.
7218 my ( $stem, @list ) = @_;
7221 # VAR_n: how many we have. Scalar assignment gets the number of items.
7222 $ENV{"${stem}_n"} = @list;
7224 # Grab each item in the list, escape the backslashes, encode the non-ASCII
7225 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
7226 for my $i ( 0 .. $#list ) {
7228 $val =~ s/\\/\\\\/g;
7229 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
7230 $ENV{"${stem}_$i"} = $val;
7231 } ## end for $i (0 .. $#list)
7232 } ## end sub set_list
7236 Reverse the set_list operation: grab VAR_n to see how many we should be getting
7237 back, and then pull VAR_0, VAR_1. etc. back out.
7244 my $n = delete $ENV{"${stem}_n"};
7246 for my $i ( 0 .. $n - 1 ) {
7247 $val = delete $ENV{"${stem}_$i"};
7248 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
7252 } ## end sub get_list
7254 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
7258 The C<catch()> subroutine is the essence of fast and low-impact. We simply
7259 set an already-existing global scalar variable to a constant value. This
7260 avoids allocating any memory possibly in the middle of something that will
7261 get all confused if we do, particularly under I<unsafe signals>.
7267 return; # Put nothing on the stack - malloc/free land!
7272 C<warn> emits a warning, by joining together its arguments and printing
7273 them, with couple of fillips.
7275 If the composited message I<doesn't> end with a newline, we automatically
7276 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
7277 to be set to the filehandle to be used to output warnings; it makes no
7278 assumptions about what filehandles are available.
7283 my ($msg) = join( "", @_ );
7284 $msg .= ": $!\n" unless $msg =~ /\n$/;
7289 =head1 INITIALIZATION TTY SUPPORT
7291 =head2 C<reset_IN_OUT>
7293 This routine handles restoring the debugger's input and output filehandles
7294 after we've tried and failed to move them elsewhere. In addition, it assigns
7295 the debugger's output filehandle to $LINEINFO if it was already open there.
7300 my $switch_li = $LINEINFO eq $OUT;
7302 # If there's a term and it's able to get a new tty, try to get one.
7303 if ( $term and $term->Features->{newTTY} ) {
7304 ( $IN, $OUT ) = ( shift, shift );
7305 $term->newTTY( $IN, $OUT );
7308 # This term can't get a new tty now. Better luck later.
7310 &warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n");
7313 # Set the filehndles up as they were.
7315 ( $IN, $OUT ) = ( shift, shift );
7318 # Unbuffer the output filehandle.
7321 # Point LINEINFO to the same output filehandle if it was there before.
7322 $LINEINFO = $OUT if $switch_li;
7323 } ## end sub reset_IN_OUT
7325 =head1 OPTION SUPPORT ROUTINES
7327 The following routines are used to process some of the more complicated
7332 Sets the input and output filehandles to the specified files or pipes.
7333 If the terminal supports switching, we go ahead and do it. If not, and
7334 there's already a terminal in place, we save the information to take effect
7337 If there's no terminal yet (for instance, during debugger initialization),
7338 we go ahead and set C<$console> and C<$tty> to the file indicated.
7344 if ( @_ and $term and $term->Features->{newTTY} ) {
7346 # This terminal supports switching to a new TTY.
7347 # Can be a list of two files, or on string containing both names,
7349 # XXX Should this perhaps be an assignment from @_?
7350 my ( $in, $out ) = shift;
7353 # Split list apart if supplied.
7354 ( $in, $out ) = split /,/, $in, 2;
7358 # Use the same file for both input and output.
7362 # Open file onto the debugger's filehandles, if you can.
7363 open IN, $in or die "cannot open '$in' for read: $!";
7364 open OUT, ">$out" or die "cannot open '$out' for write: $!";
7366 # Swap to the new filehandles.
7367 reset_IN_OUT( \*IN, \*OUT );
7369 # Save the setting for later.
7371 } ## end if (@_ and $term and $term...
7373 # Terminal doesn't support new TTY, or doesn't support readline.
7374 # Can't do it now, try restarting.
7375 &warn("Too late to set TTY, enabled on next 'R'!\n") if $term and @_;
7377 # Useful if done through PERLDB_OPTS:
7378 $console = $tty = shift if @_;
7380 # Return whatever the TTY is.
7386 Sets the C<$notty> global, controlling whether or not the debugger tries to
7387 get a terminal to read from. If called after a terminal is already in place,
7388 we save the value to use it if we're restarted.
7394 &warn("Too late to set noTTY, enabled on next 'R'!\n") if @_;
7396 $notty = shift if @_;
7402 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
7403 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
7404 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
7405 the value in case a restart is done so we can change it then.
7411 &warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_;
7415 } ## end sub ReadLine
7417 =head2 C<RemotePort>
7419 Sets the port that the debugger will try to connect to when starting up.
7420 If the terminal's already been set up, we can't do it, but we remember the
7421 setting in case the user does a restart.
7427 &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
7429 $remoteport = shift if @_;
7431 } ## end sub RemotePort
7435 Checks with the terminal to see if C<Tk> is running, and returns true or
7436 false. Returns false if the current terminal doesn't support C<readline>.
7441 if ( ${ $term->Features }{tkRunning} ) {
7442 return $term->tkRunning(@_);
7446 print $OUT "tkRunning not supported by current ReadLine package.\n";
7449 } ## end sub tkRunning
7453 Sets nonstop mode. If a terminal's already been set up, it's too late; the
7454 debugger remembers the setting in case you restart, though.
7460 &warn("Too late to set up NonStop mode, enabled on next 'R'!\n")
7463 $runnonstop = shift if @_;
7465 } ## end sub NonStop
7469 &warn("Some flag changes could not take effect until next 'R'!\n")
7472 $^P = parse_DollarCaretP_flags(shift) if @_;
7473 expand_DollarCaretP_flags($^P);
7478 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
7486 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7493 Sets the shell escape command, and generates a printable copy to be used
7500 # If we got an argument, meta-quote it, and add '\b' if it
7501 # ends in a word character.
7503 $sh = quotemeta shift;
7504 $sh .= "\\b" if $sh =~ /\w$/;
7507 # Generate the printable version for the help:
7508 $psh = $sh; # copy it
7509 $psh =~ s/\\b$//; # Take off trailing \b if any
7510 $psh =~ s/\\(.)/$1/g; # De-escape
7511 $psh; # return the printable version
7512 } ## end sub shellBang
7516 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7517 was passed as the argument. (This means you can't override the terminal's
7523 if ( defined $term ) {
7525 # We don't want to show warning backtraces, but we do want die() ones.
7526 local ( $warnLevel, $dieLevel ) = ( 0, 1 );
7528 # No ornaments if the terminal doesn't support them.
7529 return '' unless $term->Features->{ornaments};
7530 eval { $term->ornaments(@_) } || '';
7533 # Use what was passed in if we can't determine it ourselves.
7537 } ## end sub ornaments
7539 =head2 C<recallCommand>
7541 Sets the recall command, and builds a printable version which will appear in
7548 # If there is input, metaquote it. Add '\b' if it ends with a word
7551 $rc = quotemeta shift;
7552 $rc .= "\\b" if $rc =~ /\w$/;
7555 # Build it into a printable version.
7556 $prc = $rc; # Copy it
7557 $prc =~ s/\\b$//; # Remove trailing \b
7558 $prc =~ s/\\(.)/$1/g; # Remove escapes
7559 $prc; # Return the printable version
7560 } ## end sub recallCommand
7562 =head2 C<LineInfo> - where the line number information goes
7564 Called with no arguments, returns the file or pipe that line info should go to.
7566 Called with an argument (a file or a pipe), it opens that onto the
7567 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7568 file or pipe again to the caller.
7576 # If this is a valid "thing to be opened for output", tack a
7577 # '>' onto the front.
7578 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7580 # If this is a pipe, the stream points to a slave editor.
7581 $slave_editor = ( $stream =~ /^\|/ );
7583 # Open it up and unbuffer it.
7584 open( LINEINFO, $stream ) || &warn("Cannot open '$stream' for write");
7585 $LINEINFO = \*LINEINFO;
7586 $LINEINFO->autoflush(1);
7590 } ## end sub LineInfo
7592 =head1 COMMAND SUPPORT ROUTINES
7594 These subroutines provide functionality for various commands.
7596 =head2 C<list_modules>
7598 For the C<M> command: list modules loaded and their versions.
7599 Essentially just runs through the keys in %INC, picks each package's
7600 C<$VERSION> variable, gets the file name, and formats the information
7605 sub list_modules { # versions
7609 # keys are the "as-loaded" name, values are the fully-qualified path
7610 # to the file itself.
7612 $file = $_; # get the module name
7613 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7614 s,/,::,g; # change '/' to '::'
7615 s/^perl5db$/DB/; # Special case: debugger
7616 # moves to package DB
7617 s/^Term::ReadLine::readline$/readline/; # simplify readline
7619 # If the package has a $VERSION package global (as all good packages
7620 # should!) decode it and save as partial message.
7621 my $pkg_version = do { no strict 'refs'; ${ $_ . '::VERSION' } };
7622 if ( defined $pkg_version ) {
7623 $version{$file} = "$pkg_version from ";
7626 # Finish up the message with the file the package came from.
7627 $version{$file} .= $INC{$file};
7628 } ## end for (keys %INC)
7630 # Hey, dumpit() formats a hash nicely, so why not use it?
7631 dumpit( $OUT, \%version );
7632 } ## end sub list_modules
7636 Sets up the monster string used to format and print the help.
7638 =head3 HELP MESSAGE FORMAT
7640 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
7641 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
7642 easy to parse and portable, but which still allows the help to be a little
7643 nicer than just plain text.
7645 Essentially, you define the command name (usually marked up with C<< B<> >>
7646 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
7647 newline. The descriptive text can also be marked up in the same way. If you
7648 need to continue the descriptive text to another line, start that line with
7649 just tabs and then enter the marked-up text.
7651 If you are modifying the help text, I<be careful>. The help-string parser is
7652 not very sophisticated, and if you don't follow these rules it will mangle the
7653 help beyond hope until you fix the string.
7657 use vars qw($pre580_help);
7658 use vars qw($pre580_summary);
7662 # XXX: make sure there are tabs between the command and explanation,
7663 # or print_help will screw up your formatting if you have
7664 # eeevil ornaments enabled. This is an insane mess.
7667 Help is currently only available for the new 5.8 command set.
7668 No help is available for the old command set.
7669 We assume you know what you're doing if you switch to it.
7672 B<s> [I<expr>] Single step [in I<expr>].
7673 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7674 <B<CR>> Repeat last B<n> or B<s> command.
7675 B<r> Return from current subroutine.
7676 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7677 at the specified position.
7678 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7679 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7680 B<l> I<line> List single I<line>.
7681 B<l> I<subname> List first window of lines from subroutine.
7682 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7683 B<l> List next window of lines.
7684 B<-> List previous window of lines.
7685 B<v> [I<line>] View window around I<line>.
7686 B<.> Return to the executed line.
7687 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7688 I<filename> may be either the full name of the file, or a regular
7689 expression matching the full file name:
7690 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7691 Evals (with saved bodies) are considered to be filenames:
7692 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7693 (in the order of execution).
7694 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7695 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7696 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
7697 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7698 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth).
7699 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
7700 B<b> Sets breakpoint on current line)
7701 B<b> [I<line>] [I<condition>]
7702 Set breakpoint; I<line> defaults to the current execution line;
7703 I<condition> breaks if it evaluates to true, defaults to '1'.
7704 B<b> I<subname> [I<condition>]
7705 Set breakpoint at first line of subroutine.
7706 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7707 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7708 B<b> B<postpone> I<subname> [I<condition>]
7709 Set breakpoint at first line of subroutine after
7711 B<b> B<compile> I<subname>
7712 Stop after the subroutine is compiled.
7713 B<B> [I<line>] Delete the breakpoint for I<line>.
7714 B<B> I<*> Delete all breakpoints.
7715 B<a> [I<line>] I<command>
7716 Set an action to be done before the I<line> is executed;
7717 I<line> defaults to the current execution line.
7718 Sequence is: check for breakpoint/watchpoint, print line
7719 if necessary, do action, prompt user if necessary,
7722 B<A> [I<line>] Delete the action for I<line>.
7723 B<A> I<*> Delete all actions.
7724 B<w> I<expr> Add a global watch-expression.
7726 B<W> I<expr> Delete a global watch-expression.
7727 B<W> I<*> Delete all watch-expressions.
7728 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7729 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7730 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7731 B<x> I<expr> Evals expression in list context, dumps the result.
7732 B<m> I<expr> Evals expression in list context, prints methods callable
7733 on the first element of the result.
7734 B<m> I<class> Prints methods callable via the given class.
7735 B<M> Show versions of loaded modules.
7736 B<i> I<class> Prints nested parents of given class.
7737 B<e> Display current thread id.
7738 B<E> Display all thread ids the current one will be identified: <n>.
7739 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7741 B<<> ? List Perl commands to run before each prompt.
7742 B<<> I<expr> Define Perl command to run before each prompt.
7743 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7744 B<< *> Delete the list of perl commands to run before each prompt.
7745 B<>> ? List Perl commands to run after each prompt.
7746 B<>> I<expr> Define Perl command to run after each prompt.
7747 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7748 B<>>B< *> Delete the list of Perl commands to run after each prompt.
7749 B<{> I<db_command> Define debugger command to run before each prompt.
7750 B<{> ? List debugger commands to run before each prompt.
7751 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7752 B<{ *> Delete the list of debugger commands to run before each prompt.
7753 B<$prc> I<number> Redo a previous command (default previous command).
7754 B<$prc> I<-number> Redo number'th-to-last command.
7755 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7756 See 'B<O> I<recallCommand>' too.
7757 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7762 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7764 See 'B<O> I<shellBang>' too.
7765 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7766 B<save> I<file> Save current debugger session (actual history) to I<file>.
7767 B<rerun> Rerun session to current position.
7768 B<rerun> I<n> Rerun session to numbered command.
7769 B<rerun> I<-n> Rerun session to number'th-to-last command.
7770 B<H> I<-number> Display last number commands (default all).
7771 B<H> I<*> Delete complete history.
7772 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7773 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7774 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well.
7775 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7776 I<command> Execute as a perl statement in current package.
7777 B<R> Pure-man-restart of debugger, some of debugger state
7778 and command-line options may be lost.
7779 Currently the following settings are preserved:
7780 history, breakpoints and actions, debugger B<O>ptions
7781 and the following command-line options: I<-w>, I<-I>, I<-e>.
7783 B<o> [I<opt>] ... Set boolean option to true
7784 B<o> [I<opt>B<?>] Query options
7785 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7786 Set options. Use quotes if spaces in value.
7787 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7788 I<pager> program for output of \"|cmd\";
7789 I<tkRunning> run Tk while prompting (with ReadLine);
7790 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7791 I<inhibit_exit> Allows stepping off the end of the script.
7792 I<ImmediateStop> Debugger should stop as early as possible.
7793 I<RemotePort> Remote hostname:port for remote debugging
7794 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7795 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7796 I<compactDump>, I<veryCompact> change style of array and hash dump;
7797 I<globPrint> whether to print contents of globs;
7798 I<DumpDBFiles> dump arrays holding debugged files;
7799 I<DumpPackages> dump symbol tables of packages;
7800 I<DumpReused> dump contents of \"reused\" addresses;
7801 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7802 I<bareStringify> Do not print the overload-stringified value;
7803 Other options include:
7804 I<PrintRet> affects printing of return value after B<r> command,
7805 I<frame> affects printing messages on subroutine entry/exit.
7806 I<AutoTrace> affects printing messages on possible breaking points.
7807 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7808 I<ornaments> affects screen appearance of the command line.
7809 I<CreateTTY> bits control attempts to create a new TTY on events:
7810 1: on fork() 2: debugger is started inside debugger
7812 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7813 You can put additional initialization options I<TTY>, I<noTTY>,
7814 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7815 B<R> after you set them).
7817 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7818 B<h> Summary of debugger commands.
7819 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7820 B<h h> Long help for debugger commands
7821 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7822 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7823 Set B<\$DB::doccmd> to change viewer.
7825 Type '|h h' for a paged display if this was too hard to read.
7827 "; # Fix balance of vi % matching: }}}}
7829 # note: tabs in the following section are not-so-helpful
7830 $summary = <<"END_SUM";
7831 I<List/search source lines:> I<Control script execution:>
7832 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7833 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7834 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7835 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7836 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7837 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7838 I<Debugger controls:> B<L> List break/watch/actions
7839 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr]
7840 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7841 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7842 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7843 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7844 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7845 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7846 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7847 B<q> or B<^D> Quit B<R> Attempt a restart
7848 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7849 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7850 B<p> I<expr> Print expression (uses script's current package).
7851 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7852 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7853 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
7854 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7855 B<e> Display thread id B<E> Display all thread ids.
7856 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7859 # ')}}; # Fix balance of vi % matching
7861 # and this is really numb...
7864 B<s> [I<expr>] Single step [in I<expr>].
7865 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7866 B<CR>> Repeat last B<n> or B<s> command.
7867 B<r> Return from current subroutine.
7868 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7869 at the specified position.
7870 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7871 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7872 B<l> I<line> List single I<line>.
7873 B<l> I<subname> List first window of lines from subroutine.
7874 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7875 B<l> List next window of lines.
7876 B<-> List previous window of lines.
7877 B<w> [I<line>] List window around I<line>.
7878 B<.> Return to the executed line.
7879 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7880 I<filename> may be either the full name of the file, or a regular
7881 expression matching the full file name:
7882 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7883 Evals (with saved bodies) are considered to be filenames:
7884 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7885 (in the order of execution).
7886 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7887 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7888 B<L> List all breakpoints and actions.
7889 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7890 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) .
7891 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
7892 B<b> [I<line>] [I<condition>]
7893 Set breakpoint; I<line> defaults to the current execution line;
7894 I<condition> breaks if it evaluates to true, defaults to '1'.
7895 B<b> I<subname> [I<condition>]
7896 Set breakpoint at first line of subroutine.
7897 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7898 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7899 B<b> B<postpone> I<subname> [I<condition>]
7900 Set breakpoint at first line of subroutine after
7902 B<b> B<compile> I<subname>
7903 Stop after the subroutine is compiled.
7904 B<d> [I<line>] Delete the breakpoint for I<line>.
7905 B<D> Delete all breakpoints.
7906 B<a> [I<line>] I<command>
7907 Set an action to be done before the I<line> is executed;
7908 I<line> defaults to the current execution line.
7909 Sequence is: check for breakpoint/watchpoint, print line
7910 if necessary, do action, prompt user if necessary,
7912 B<a> [I<line>] Delete the action for I<line>.
7913 B<A> Delete all actions.
7914 B<W> I<expr> Add a global watch-expression.
7915 B<W> Delete all watch-expressions.
7916 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7917 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7918 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7919 B<x> I<expr> Evals expression in list context, dumps the result.
7920 B<m> I<expr> Evals expression in list context, prints methods callable
7921 on the first element of the result.
7922 B<m> I<class> Prints methods callable via the given class.
7924 B<<> ? List Perl commands to run before each prompt.
7925 B<<> I<expr> Define Perl command to run before each prompt.
7926 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7927 B<>> ? List Perl commands to run after each prompt.
7928 B<>> I<expr> Define Perl command to run after each prompt.
7929 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7930 B<{> I<db_command> Define debugger command to run before each prompt.
7931 B<{> ? List debugger commands to run before each prompt.
7932 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7933 B<$prc> I<number> Redo a previous command (default previous command).
7934 B<$prc> I<-number> Redo number'th-to-last command.
7935 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7936 See 'B<O> I<recallCommand>' too.
7937 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7942 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7944 See 'B<O> I<shellBang>' too.
7945 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7946 B<H> I<-number> Display last number commands (default all).
7947 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7948 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7949 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7950 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7951 I<command> Execute as a perl statement in current package.
7952 B<v> Show versions of loaded modules.
7953 B<R> Pure-man-restart of debugger, some of debugger state
7954 and command-line options may be lost.
7955 Currently the following settings are preserved:
7956 history, breakpoints and actions, debugger B<O>ptions
7957 and the following command-line options: I<-w>, I<-I>, I<-e>.
7959 B<O> [I<opt>] ... Set boolean option to true
7960 B<O> [I<opt>B<?>] Query options
7961 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7962 Set options. Use quotes if spaces in value.
7963 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7964 I<pager> program for output of \"|cmd\";
7965 I<tkRunning> run Tk while prompting (with ReadLine);
7966 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7967 I<inhibit_exit> Allows stepping off the end of the script.
7968 I<ImmediateStop> Debugger should stop as early as possible.
7969 I<RemotePort> Remote hostname:port for remote debugging
7970 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7971 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7972 I<compactDump>, I<veryCompact> change style of array and hash dump;
7973 I<globPrint> whether to print contents of globs;
7974 I<DumpDBFiles> dump arrays holding debugged files;
7975 I<DumpPackages> dump symbol tables of packages;
7976 I<DumpReused> dump contents of \"reused\" addresses;
7977 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7978 I<bareStringify> Do not print the overload-stringified value;
7979 Other options include:
7980 I<PrintRet> affects printing of return value after B<r> command,
7981 I<frame> affects printing messages on subroutine entry/exit.
7982 I<AutoTrace> affects printing messages on possible breaking points.
7983 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7984 I<ornaments> affects screen appearance of the command line.
7985 I<CreateTTY> bits control attempts to create a new TTY on events:
7986 1: on fork() 2: debugger is started inside debugger
7988 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7989 You can put additional initialization options I<TTY>, I<noTTY>,
7990 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7991 B<R> after you set them).
7993 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7994 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7995 B<h h> Summary of debugger commands.
7996 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7997 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7998 Set B<\$DB::doccmd> to change viewer.
8000 Type '|h' for a paged display if this was too hard to read.
8002 "; # Fix balance of vi % matching: }}}}
8004 # note: tabs in the following section are not-so-helpful
8005 $pre580_summary = <<"END_SUM";
8006 I<List/search source lines:> I<Control script execution:>
8007 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8008 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8009 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
8010 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8011 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8012 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
8013 I<Debugger controls:> B<L> List break/watch/actions
8014 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
8015 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8016 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
8017 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8018 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
8019 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
8020 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8021 B<q> or B<^D> Quit B<R> Attempt a restart
8022 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8023 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8024 B<p> I<expr> Print expression (uses script's current package).
8025 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8026 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8027 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
8028 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8029 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8032 # ')}}; # Fix balance of vi % matching
8034 } ## end sub sethelp
8036 =head2 C<print_help()>
8038 Most of what C<print_help> does is just text formatting. It finds the
8039 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
8040 terminal control characters to simulate them (courtesy of
8041 C<Term::ReadLine::TermCap>).
8046 my $help_str = shift;
8048 # Restore proper alignment destroyed by eeevil I<> and B<>
8049 # ornaments: A pox on both their houses!
8051 # A help command will have everything up to and including
8052 # the first tab sequence padded into a field 16 (or if indented 20)
8053 # wide. If it's wider than that, an extra space will be added.
8055 ^ # only matters at start of line
8056 ( \040{4} | \t )* # some subcommands are indented
8057 ( < ? # so <CR> works
8058 [BI] < [^\t\n] + ) # find an eeevil ornament
8059 ( \t+ ) # original separation, discarded
8060 ( .* ) # this will now start (no earlier) than
8063 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
8064 my $clean = $command;
8065 $clean =~ s/[BI]<([^>]*)>/$1/g;
8067 # replace with this whole string:
8068 ($leadwhite ? " " x 4 : "")
8070 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
8075 $help_str =~ s{ # handle bold ornaments
8076 B < ( [^>] + | > ) >
8078 $Term::ReadLine::TermCap::rl_term_set[2]
8080 . $Term::ReadLine::TermCap::rl_term_set[3]
8083 $help_str =~ s{ # handle italic ornaments
8084 I < ( [^>] + | > ) >
8086 $Term::ReadLine::TermCap::rl_term_set[0]
8088 . $Term::ReadLine::TermCap::rl_term_set[1]
8092 print {$OUT} $help_str;
8095 } ## end sub print_help
8099 This routine does a lot of gyrations to be sure that the pager is C<less>.
8100 It checks for C<less> masquerading as C<more> and records the result in
8101 C<$fixed_less> so we don't have to go through doing the stats again.
8105 use vars qw($fixed_less);
8108 if ($pager =~ /\bless\b/)
8112 elsif ($pager =~ /\bmore\b/)
8114 # Nope, set to more. See what's out there.
8115 my @st_more = stat('/usr/bin/more');
8116 my @st_less = stat('/usr/bin/less');
8118 # is it really less, pretending to be more?
8122 && $st_more[0] == $st_less[0]
8123 && $st_more[1] == $st_less[1]
8133 # We already know if this is set.
8134 return if $fixed_less;
8136 # changes environment!
8137 # 'r' added so we don't do (slow) stats again.
8138 $fixed_less = 1 if _calc_is_less();
8141 } ## end sub fix_less
8143 =head1 DIE AND WARN MANAGEMENT
8147 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
8148 to debug a debugger problem.
8150 It does its best to report the error that occurred, and then forces the
8151 program, debugger, and everything to die.
8157 # No entry/exit messages.
8160 # No return value prints.
8163 # set the abort signal handling to the default (just terminate).
8164 $SIG{'ABRT'} = 'DEFAULT';
8166 # If we enter the signal handler recursively, kill myself with an
8167 # abort signal (so we just terminate).
8168 kill 'ABRT', $$ if $panic++;
8170 # If we can show detailed info, do so.
8171 if ( defined &Carp::longmess ) {
8173 # Don't recursively enter the warn handler, since we're carping.
8174 local $SIG{__WARN__} = '';
8176 # Skip two levels before reporting traceback: we're skipping
8177 # mydie and confess.
8178 local $Carp::CarpLevel = 2; # mydie + confess
8180 # Tell us all about it.
8181 &warn( Carp::longmess("Signal @_") );
8184 # No Carp. Tell us about the signal as best we can.
8187 print $DB::OUT "Got signal @_\n";
8192 } ## end sub diesignal
8196 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
8197 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
8203 # No entry/exit trace.
8206 # No return value printing.
8209 # Turn off warn and die handling to prevent recursive entries to this
8211 local $SIG{__WARN__} = '';
8212 local $SIG{__DIE__} = '';
8214 # Load Carp if we can. If $^S is false (current thing being compiled isn't
8215 # done yet), we may not be able to do a require.
8216 eval { require Carp }
8217 if defined $^S; # If error/warning during compilation,
8218 # require may be broken.
8220 # Use the core warn() unless Carp loaded OK.
8222 "\nCannot print stack trace, load with -MCarp option to see stack" ),
8224 unless defined &Carp::longmess;
8226 # Save the current values of $single and $trace, and then turn them off.
8227 my ( $mysingle, $mytrace ) = ( $single, $trace );
8231 # We can call Carp::longmess without its being "debugged" (which we
8232 # don't want - we just want to use it!). Capture this for later.
8233 my $mess = Carp::longmess(@_);
8235 # Restore $single and $trace to their original values.
8236 ( $single, $trace ) = ( $mysingle, $mytrace );
8238 # Use the debugger's own special way of printing warnings to print
8239 # the stack trace message.
8245 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
8246 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
8247 single stepping and tracing during the call to C<Carp::longmess> to avoid
8248 debugging it - we just want to use it.
8250 If C<dieLevel> is zero, we let the program being debugged handle the
8251 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
8252 the debugger takes over all exception handling, printing a backtrace and
8253 displaying the exception via its C<dbwarn()> routine.
8260 local $SIG{__DIE__} = '';
8261 local $SIG{__WARN__} = '';
8265 if ( $dieLevel > 2 ) {
8266 local $SIG{__WARN__} = \&dbwarn;
8267 &warn(@_); # Yell no matter what
8270 if ( $dieLevel < 2 ) {
8271 die @_ if $^S; # in eval propagate
8274 # The code used to check $^S to see if compilation of the current thing
8275 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
8276 eval { require Carp };
8279 "\nCannot print stack trace, load with -MCarp option to see stack" )
8280 unless defined &Carp::longmess;
8282 # We do not want to debug this chunk (automatic disabling works
8283 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
8284 # get the stack trace from Carp::longmess (if possible), restore $signal
8285 # and $trace, and then die with the stack trace.
8286 my ( $mysingle, $mytrace ) = ( $single, $trace );
8292 package Carp; # Do not include us in the list
8293 eval { $mess = Carp::longmess(@_); };
8295 ( $single, $trace ) = ( $mysingle, $mytrace );
8299 =head2 C<warnlevel()>
8301 Set the C<$DB::warnLevel> variable that stores the value of the
8302 C<warnLevel> option. Calling C<warnLevel()> with a positive value
8303 results in the debugger taking over all warning handlers. Setting
8304 C<warnLevel> to zero leaves any warning handlers set up by the program
8305 being debugged in place.
8311 my $prevwarn = $SIG{__WARN__} unless $warnLevel;
8314 $SIG{__WARN__} = \&DB::dbwarn;
8317 $SIG{__WARN__} = $prevwarn;
8319 undef $SIG{__WARN__};
8323 } ## end sub warnLevel
8327 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
8328 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
8329 zero lets you use your own C<die()> handler.
8336 my $prevdie = $SIG{__DIE__} unless $dieLevel;
8340 # Always set it to dbdie() for non-zero values.
8341 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
8343 # No longer exists, so don't try to use it.
8344 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
8346 # If we've finished initialization, mention that stack dumps
8347 # are enabled, If dieLevel is 1, we won't stack dump if we die
8349 print $OUT "Stack dump during die enabled",
8350 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
8353 # XXX This is probably obsolete, given that diehard() is gone.
8354 print $OUT "Dump printed too.\n" if $dieLevel > 2;
8355 } ## end if ($dieLevel)
8357 # Put the old one back if there was one.
8359 $SIG{__DIE__} = $prevdie;
8360 print $OUT "Default die handler restored.\n";
8362 undef $SIG{__DIE__};
8363 print $OUT "Die handler removed.\n";
8367 } ## end sub dieLevel
8369 =head2 C<signalLevel>
8371 Number three in a series: set C<signalLevel> to zero to keep your own
8372 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
8373 takes over and handles them with C<DB::diesignal()>.
8379 my $prevsegv = $SIG{SEGV} unless $signalLevel;
8380 my $prevbus = $SIG{BUS} unless $signalLevel;
8381 $signalLevel = shift;
8383 $SIG{SEGV} = \&DB::diesignal;
8384 $SIG{BUS} = \&DB::diesignal;
8387 $SIG{SEGV} = $prevsegv;
8388 $SIG{BUS} = $prevbus;
8392 } ## end sub signalLevel
8394 =head1 SUBROUTINE DECODING SUPPORT
8396 These subroutines are used during the C<x> and C<X> commands to try to
8397 produce as much information as possible about a code reference. They use
8398 L<Devel::Peek> to try to find the glob in which this code reference lives
8399 (if it does) - this allows us to actually code references which correspond
8400 to named subroutines (including those aliased via glob assignment).
8402 =head2 C<CvGV_name()>
8404 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
8405 via that routine. If this fails, return the reference again (when the
8406 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
8412 my $name = CvGV_name_or_bust($in);
8413 defined $name ? $name : $in;
8416 =head2 C<CvGV_name_or_bust> I<coderef>
8418 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
8419 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
8420 find a glob for this ref.
8422 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
8426 use vars qw($skipCvGV);
8428 sub CvGV_name_or_bust {
8430 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
8431 return unless ref $in;
8432 $in = \&$in; # Hard reference...
8433 eval { require Devel::Peek; 1 } or return;
8434 my $gv = Devel::Peek::CvGV($in) or return;
8435 *$gv{PACKAGE} . '::' . *$gv{NAME};
8436 } ## end sub CvGV_name_or_bust
8440 A utility routine used in various places; finds the file where a subroutine
8441 was defined, and returns that filename and a line-number range.
8443 Tries to use C<@sub> first; if it can't find it there, it tries building a
8444 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
8445 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
8446 this way, it brute-force searches C<%sub>, checking for identical references.
8450 sub _find_sub_helper {
8453 return unless defined &$subr;
8454 my $name = CvGV_name_or_bust($subr);
8456 $data = $sub{$name} if defined $name;
8457 return $data if defined $data;
8460 $subr = \&$subr; # Hard reference
8463 $s = $_, last if $subr eq \&$_;
8478 return ( $sub{$subr} || _find_sub_helper($subr) );
8479 } ## end sub find_sub
8483 A subroutine that uses the utility function C<methods_via> to find all the
8484 methods in the class corresponding to the current reference and in
8493 # Figure out the class - either this is the class or it's a reference
8494 # to something blessed into that class.
8496 $class = ref $class if ref $class;
8500 # Show the methods that this class has.
8501 methods_via( $class, '', 1 );
8503 # Show the methods that UNIVERSAL has.
8504 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
8505 } ## end sub methods
8507 =head2 C<methods_via($class, $prefix, $crawl_upward)>
8509 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
8510 all the parent class methods. C<$class> is the name of the next class to
8511 try; C<$prefix> is the message prefix, which gets built up as we go up the
8512 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
8513 higher in the C<@ISA> tree, 0 if we should stop.
8519 # If we've processed this class already, just quit.
8521 return if $seen{$class}++;
8523 # This is a package that is contributing the methods we're about to print.
8525 my $prepend = $prefix ? "via $prefix: " : '';
8528 # Extract from all the symbols in this class.
8529 my $class_ref = do { no strict "refs"; \%{$class . '::'} };
8530 while (my ($name, $glob) = each %$class_ref) {
8531 # references directly in the symbol table are Proxy Constant
8532 # Subroutines, and are by their very nature defined
8533 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8534 # to a subroutine reference, which can be tested by defined.
8535 # $glob might also be the value -1 (from sub foo;)
8536 # or (say) '$$' (from sub foo ($$);)
8537 # \$glob will be SCALAR in both cases.
8538 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8539 && !$seen{$name}++) {
8540 push @to_print, "$prepend$name\n";
8547 print $DB::OUT $_ foreach sort @to_print;
8550 # If the $crawl_upward argument is false, just quit here.
8551 return unless shift;
8553 # $crawl_upward true: keep going up the tree.
8554 # Find all the classes this one is a subclass of.
8555 my $class_ISA_ref = do { no strict "refs"; \@{"${class}::ISA"} };
8556 for my $name ( @$class_ISA_ref ) {
8558 # Set up the new prefix.
8559 $prepend = $prefix ? $prefix . " -> $name" : $name;
8561 # Crawl up the tree and keep trying to crawl up.
8562 methods_via( $name, $prepend, 1 );
8564 } ## end sub methods_via
8566 =head2 C<setman> - figure out which command to use to show documentation
8568 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8573 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|NetWare)\z/s
8574 ? "man" # O Happy Day!
8575 : "perldoc"; # Alas, poor unfortunates
8578 =head2 C<runman> - run the appropriate command to show documentation
8580 Accepts a man page name; runs the appropriate command to display it (set up
8581 during debugger initialization). Uses C<DB::system> to avoid mucking up the
8582 program's STDIN and STDOUT.
8586 my %_is_in_pods = (map { $_ => 1 }
8724 &system("$doccmd $doccmd");
8728 # this way user can override, like with $doccmd="man -Mwhatever"
8729 # or even just "man " to disable the path check.
8730 unless ( $doccmd eq 'man' ) {
8731 &system("$doccmd $page");
8735 $page = 'perl' if lc($page) eq 'help';
8738 my $man1dir = $Config::Config{'man1dir'};
8739 my $man3dir = $Config::Config{'man3dir'};
8740 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8742 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8743 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8744 chop $manpath if $manpath;
8746 # harmless if missing, I figure
8747 my $oldpath = $ENV{MANPATH};
8748 $ENV{MANPATH} = $manpath if $manpath;
8749 my $nopathopt = $^O =~ /dunno what goes here/;
8754 # I just *know* there are men without -M
8755 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8760 unless ( $page =~ /^perl\w/ ) {
8761 # do it this way because its easier to slurp in to keep up to date - clunky though.
8762 if (exists($_is_in_pods{$page})) {
8763 CORE::system( $doccmd,
8764 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8768 } ## end if (CORE::system($doccmd...
8769 if ( defined $oldpath ) {
8770 $ENV{MANPATH} = $manpath;
8773 delete $ENV{MANPATH};
8777 #use Carp; # This did break, left for debugging
8779 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
8781 Because of the way the debugger interface to the Perl core is designed, any
8782 debugger package globals that C<DB::sub()> requires have to be defined before
8783 any subroutines can be called. These are defined in the second C<BEGIN> block.
8785 This block sets things up so that (basically) the world is sane
8786 before the debugger starts executing. We set up various variables that the
8787 debugger has to have set up before the Perl core starts running:
8793 The debugger's own filehandles (copies of STD and STDOUT for now).
8797 Characters for shell escapes, the recall command, and the history command.
8801 The maximum recursion depth.
8805 The size of a C<w> command's window.
8809 The before-this-line context to be printed in a C<v> (view a window around this line) command.
8813 The fact that we're not in a sub at all right now.
8817 The default SIGINT handler for the debugger.
8821 The appropriate value of the flag in C<$^D> that says the debugger is running
8825 The current debugger recursion level
8829 The list of postponed items and the C<$single> stack (XXX define this)
8833 That we want no return values and no subroutine entry/exit trace.
8839 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
8841 use vars qw($db_stop);
8843 BEGIN { # This does not compile, alas. (XXX eh?)
8844 $IN = \*STDIN; # For bugs before DB::OUT has been opened
8845 $OUT = \*STDERR; # For errors before DB::OUT has been opened
8847 # Define characters used by command parsing.
8848 $sh = '!'; # Shell escape (does not work)
8849 $rc = ','; # Recall command (does not work)
8850 @hist = ('?'); # Show history (does not work)
8851 @truehist = (); # Can be saved for replay (per session)
8853 # This defines the point at which you get the 'deep recursion'
8854 # warning. It MUST be defined or the debugger will not load.
8857 # Number of lines around the current one that are shown in the
8861 # How much before-the-current-line context the 'v' command should
8862 # use in calculating the start of the window it will display.
8865 # We're not in any sub yet, but we need this to be a defined value.
8868 # Set up the debugger's interrupt handler. It simply sets a flag
8869 # ($signal) that DB::DB() will check before each command is executed.
8870 $SIG{INT} = \&DB::catch;
8872 # The following lines supposedly, if uncommented, allow the debugger to
8873 # debug itself. Perhaps we can try that someday.
8874 # This may be enabled to debug debugger:
8875 #$warnLevel = 1 unless defined $warnLevel;
8876 #$dieLevel = 1 unless defined $dieLevel;
8877 #$signalLevel = 1 unless defined $signalLevel;
8879 # This is the flag that says "a debugger is running, please call
8880 # DB::DB and DB::sub". We will turn it on forcibly before we try to
8881 # execute anything in the user's context, because we always want to
8883 $db_stop = 0; # Compiler warning ...
8884 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
8886 # This variable records how many levels we're nested in debugging. Used
8887 # Used in the debugger prompt, and in determining whether it's all over or
8889 $level = 0; # Level of recursive debugging
8891 # "Triggers bug (?) in perl if we postpone this until runtime."
8892 # XXX No details on this yet, or whether we should fix the bug instead
8893 # of work around it. Stay tuned.
8896 # Used to track the current stack depth using the auto-stacked-variable
8898 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
8900 # Don't print return values on exiting a subroutine.
8903 # No extry/exit tracing.
8908 BEGIN { $^W = $ini_warn; } # Switch warnings back
8910 =head1 READLINE SUPPORT - COMPLETION FUNCTION
8914 C<readline> support - adds command completion to basic C<readline>.
8916 Returns a list of possible completions to C<readline> when invoked. C<readline>
8917 will print the longest common substring following the text already entered.
8919 If there is only a single possible completion, C<readline> will use it in full.
8921 This code uses C<map> and C<grep> heavily to create lists of possible
8922 completion. Think LISP in this section.
8928 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
8929 # $text is the text to be completed.
8930 # $line is the incoming line typed by the user.
8931 # $start is the start of the text to be completed in the incoming line.
8932 my ( $text, $line, $start ) = @_;
8934 # Save the initial text.
8935 # The search pattern is current package, ::, extract the next qualifier
8936 # Prefix and pack are set to undef.
8937 my ( $itext, $search, $prefix, $pack ) =
8938 ( $text, "^\Q${package}::\E([^:]+)\$" );
8940 =head3 C<b postpone|compile>
8946 Find all the subroutines that might match in this package
8950 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
8954 Include all the rest of the subs that are known
8958 C<grep> out the ones that match the text we have so far
8962 Return this as the list of possible completions
8968 return sort grep /^\Q$text/, ( keys %sub ),
8969 qw(postpone load compile), # subroutines
8970 ( map { /$search/ ? ($1) : () } keys %sub )
8971 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
8975 Get all the possible files from C<@INC> as it currently stands and
8976 select the ones that match the text so far.
8980 return sort grep /^\Q$text/, values %INC # files
8981 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
8983 =head3 C<V> (list variable) and C<m> (list modules)
8985 There are two entry points for these commands:
8987 =head4 Unqualified package names
8989 Get the top-level packages and grab everything that matches the text
8990 so far. For each match, recursively complete the partial packages to
8991 get all possible matching packages. Return this sorted list.
8995 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8996 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
8997 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
8999 =head4 Qualified package names
9001 Take a partially-qualified package and find all subpackages for it
9002 by getting all the subpackages for the package so far, matching all
9003 the subpackages against the text, and discarding all of them which
9004 start with 'main::'. Return this list.
9008 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9009 grep !/^main::/, grep /^\Q$text/,
9010 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () }
9011 do { no strict 'refs'; keys %{ $prefix . '::' } }
9012 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
9013 and $text =~ /^(.*[^:])::?(\w*)$/
9016 =head3 C<f> - switch files
9018 Here, we want to get a fully-qualified filename for the C<f> command.
9023 =item 1. The original source file itself
9025 =item 2. A file from C<@INC>
9027 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
9033 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
9034 # We might possibly want to switch to an eval (which has a "filename"
9035 # like '(eval 9)'), so we may need to clean up the completion text
9036 # before proceeding.
9037 $prefix = length($1) - length($text);
9042 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
9043 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
9044 out of C<%main::>, add the initial source file, and extract the ones that
9045 match the completion text so far.
9050 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
9052 } ## end if ($line =~ /^\|*f\s+(.*)/)
9054 =head3 Subroutine name completion
9056 We look through all of the defined subs (the keys of C<%sub>) and
9057 return both all the possible matches to the subroutine name plus
9058 all the matches qualified to the current package.
9062 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
9063 $text = substr $text, 1;
9065 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
9067 map { /$search/ ? ($1) : () }
9070 } ## end if ((substr $text, 0, ...
9072 =head3 Scalar, array, and hash completion: partially qualified package
9074 Much like the above, except we have to do a little more cleanup:
9078 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
9086 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
9090 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
9096 Figure out the prefix vs. what needs completing.
9100 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
9107 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
9113 map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
9121 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.
9125 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9126 return db_complete( $out[0], $line, $start );
9129 # Return the list of possibles.
9132 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
9138 =head3 Symbol completion: current package or package C<main>.
9142 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
9149 If it's C<main>, delete main to just get C<::> leading.
9153 $pack = ( $package eq 'main' ? '' : $package ) . '::';
9159 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
9163 $prefix = substr $text, 0, 1;
9164 $text = substr $text, 1;
9172 We look for the lexical scope above DB::DB and auto-complete lexical variables
9173 if PadWalker could be loaded.
9177 if (not $text =~ /::/ and eval { require PadWalker } ) {
9180 my @info = caller($level);
9184 last if $info[3] eq 'DB::DB';
9187 my $lexicals = PadWalker::peek_my($level);
9188 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
9196 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
9200 push @out, map "$prefix$_", grep /^\Q$text/,
9201 ( grep /^_?[a-zA-Z]/, keys %$pack ),
9202 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
9206 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
9212 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9213 return db_complete( $out[0], $line, $start );
9216 # Return the list of possibles.
9218 } ## end if ($text =~ /^[\$@%]/)
9222 We use C<option_val()> to look up the current value of the option. If there's
9223 only a single value, we complete the command in such a way that it is a
9224 complete command for setting the option in question. If there are multiple
9225 possible values, we generate a command consisting of the option plus a trailing
9226 question mark, which, if executed, will list the current value of the option.
9230 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
9231 { # Options after space
9232 # We look for the text to be matched in the list of possible options,
9233 # and fetch the current value.
9234 my @out = grep /^\Q$text/, @options;
9235 my $val = option_val( $out[0], undef );
9237 # Set up a 'query option's value' command.
9239 if ( not defined $val or $val =~ /[\n\r]/ ) {
9241 # There's really nothing else we can do.
9244 # We have a value. Create a proper option-setting command.
9245 elsif ( $val =~ /\s/ ) {
9247 # XXX This may be an extraneous variable.
9250 # We'll want to quote the string (because of the embedded
9251 # whtespace), but we want to make sure we don't end up with
9252 # mismatched quote characters. We try several possibilities.
9253 foreach my $l ( split //, qq/\"\'\#\|/ ) {
9255 # If we didn't find this quote character in the value,
9256 # quote it using this quote character.
9257 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
9259 } ## end elsif ($val =~ /\s/)
9261 # Don't need any quotes.
9266 # If there were multiple possible values, return '? ', which
9267 # makes the command into a query command. If there was just one,
9268 # have readline append that.
9269 $rl_attribs->{completer_terminator_character} =
9270 ( @out == 1 ? $out : '? ' );
9272 # Return list of possibilities.
9274 } ## end if ((substr $line, 0, ...
9276 =head3 Filename completion
9278 For entering filenames. We simply call C<readline>'s C<filename_list()>
9279 method with the completion text to get the possible completions.
9283 return $term->filename_list($text); # filenames
9285 } ## end sub db_complete
9287 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
9289 Functions that possibly ought to be somewhere else.
9299 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n";
9304 If we have $ini_pids, save it in the environment; else remove it from the
9305 environment. Used by the C<R> (restart) command.
9310 if ( defined($ini_pids) ) {
9311 $ENV{PERLDB_PIDS} = $ini_pids;
9314 delete( $ENV{PERLDB_PIDS} );
9316 } ## end sub clean_ENV
9318 # PERLDBf_... flag names from perl.h
9319 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
9322 %DollarCaretP_flags = (
9323 PERLDBf_SUB => 0x01, # Debug sub enter/exit
9324 PERLDBf_LINE => 0x02, # Keep line #
9325 PERLDBf_NOOPT => 0x04, # Switch off optimizations
9326 PERLDBf_INTER => 0x08, # Preserve more data
9327 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
9328 PERLDBf_SINGLE => 0x20, # Start with single-step on
9329 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
9330 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
9331 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
9332 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
9333 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
9334 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
9336 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
9337 # doesn't need to set it. It's provided for the benefit of profilers and
9338 # other code analysers.
9340 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
9343 sub parse_DollarCaretP_flags {
9348 foreach my $f ( split /\s*\|\s*/, $flags ) {
9350 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
9353 elsif ( $f =~ /^(\d+)$/ ) {
9356 elsif ( $f =~ /^DEFAULT$/i ) {
9357 $value = $DollarCaretP_flags{PERLDB_ALL};
9360 $f =~ /^(?:PERLDBf_)?(.*)$/i;
9361 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
9362 unless ( defined $value ) {
9364 "Unrecognized \$^P flag '$f'!\n",
9365 "Acceptable flags are: "
9366 . join( ', ', sort keys %DollarCaretP_flags ),
9367 ", and hexadecimal and decimal numbers.\n"
9377 sub expand_DollarCaretP_flags {
9378 my $DollarCaretP = shift;
9381 my $n = ( 1 << $_ );
9382 ( $DollarCaretP & $n )
9383 ? ( $DollarCaretP_flags_r{$n}
9384 || sprintf( '0x%x', $n ) )
9388 return @bits ? join( '|', @bits ) : 0;
9395 Rerun the current session to:
9397 rerun current position
9399 rerun 4 command number 4
9401 rerun -4 current command minus 4 (go back 4 steps)
9403 Whether this always makes sense, in the current context is unknowable, and is
9404 in part left as a useful exercise for the reader. This sub returns the
9405 appropriate arguments to rerun the current session.
9412 pop(@truehist); # strim
9413 unless (defined $truehist[$i]) {
9414 print "Unable to return to non-existent command: $i\n";
9416 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
9417 my @temp = @truehist; # store
9418 push(@DB::typeahead, @truehist); # saved
9419 @truehist = @hist = (); # flush
9420 @args = &restart(); # setup
9421 &get_list("PERLDB_HIST"); # clean
9422 &set_list("PERLDB_HIST", @temp); # reset
9429 Restarting the debugger is a complex operation that occurs in several phases.
9430 First, we try to reconstruct the command line that was used to invoke Perl
9436 # I may not be able to resurrect you, but here goes ...
9438 "Warning: some settings and command-line options may be lost!\n";
9439 my ( @script, @flags, $cl );
9441 # If warn was on before, turn it on again.
9442 push @flags, '-w' if $ini_warn;
9444 # Rebuild the -I flags that were on the initial
9447 push @flags, '-I', $_;
9450 # Turn on taint if it was on before.
9451 push @flags, '-T' if ${^TAINT};
9453 # Arrange for setting the old INC:
9454 # Save the current @init_INC in the environment.
9455 set_list( "PERLDB_INC", @ini_INC );
9457 # If this was a perl one-liner, go to the "file"
9458 # corresponding to the one-liner read all the lines
9459 # out of it (except for the first one, which is going
9460 # to be added back on again when 'perl -d' runs: that's
9461 # the 'require perl5db.pl;' line), and add them back on
9462 # to the command line to be executed.
9464 my $lines = *{$main::{'_<-e'}}{ARRAY};
9465 for ( 1 .. $#$lines ) { # The first line is PERL5DB
9466 chomp( $cl = $lines->[$_] );
9467 push @script, '-e', $cl;
9469 } ## end if ($0 eq '-e')
9471 # Otherwise we just reuse the original name we had
9479 After the command line has been reconstructed, the next step is to save
9480 the debugger's status in environment variables. The C<DB::set_list> routine
9481 is used to save aggregate variables (both hashes and arrays); scalars are
9482 just popped into environment variables directly.
9486 # If the terminal supported history, grab it and
9487 # save that in the environment.
9488 set_list( "PERLDB_HIST",
9489 $term->Features->{getHistory}
9493 # Find all the files that were visited during this
9494 # session (i.e., the debugger had magic hashes
9495 # corresponding to them) and stick them in the environment.
9496 my @had_breakpoints = keys %had_breakpoints;
9497 set_list( "PERLDB_VISITED", @had_breakpoints );
9499 # Save the debugger options we chose.
9500 set_list( "PERLDB_OPT", %option );
9501 # set_list( "PERLDB_OPT", options2remember() );
9503 # Save the break-on-loads.
9504 set_list( "PERLDB_ON_LOAD", %break_on_load );
9508 The most complex part of this is the saving of all of the breakpoints. They
9509 can live in an awful lot of places, and we have to go through all of them,
9510 find the breakpoints, and then save them in the appropriate environment
9511 variable via C<DB::set_list>.
9515 # Go through all the breakpoints and make sure they're
9518 for ( 0 .. $#had_breakpoints ) {
9520 # We were in this file.
9521 my $file = $had_breakpoints[$_];
9523 # Grab that file's magic line hash.
9524 *dbline = $main::{ '_<' . $file };
9526 # Skip out if it doesn't exist, or if the breakpoint
9527 # is in a postponed file (we'll do postponed ones
9529 next unless %dbline or $postponed_file{$file};
9531 # In an eval. This is a little harder, so we'll
9532 # do more processing on that below.
9533 ( push @hard, $file ), next
9534 if $file =~ /^\(\w*eval/;
9536 # XXX I have no idea what this is doing. Yet.
9538 @add = %{ $postponed_file{$file} }
9539 if $postponed_file{$file};
9541 # Save the list of all the breakpoints for this file.
9542 set_list( "PERLDB_FILE_$_", %dbline, @add );
9544 # Serialize the extra data %breakpoints_data hash.
9546 set_list( "PERLDB_FILE_ENABLED_$_",
9547 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 }
9548 sort { $a <=> $b } keys(%dbline)
9550 } ## end for (0 .. $#had_breakpoints)
9552 # The breakpoint was inside an eval. This is a little
9553 # more difficult. XXX and I don't understand it.
9555 # Get over to the eval in question.
9556 *dbline = $main::{ '_<' . $_ };
9557 my ( $quoted, $sub, %subs, $line ) = quotemeta $_;
9558 for $sub ( keys %sub ) {
9559 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
9560 $subs{$sub} = [ $1, $2 ];
9564 "No subroutines in $_, ignoring breakpoints.\n";
9567 LINES: for $line ( keys %dbline ) {
9569 # One breakpoint per sub only:
9570 my ( $offset, $sub, $found );
9571 SUBS: for $sub ( keys %subs ) {
9574 $line # Not after the subroutine
9576 not defined $offset # Not caught
9582 $offset = $line - $subs{$sub}->[0];
9583 $offset = "+$offset", last SUBS
9585 } ## end if ($subs{$sub}->[1] >=...
9586 } ## end for $sub (keys %subs)
9587 if ( defined $offset ) {
9588 $postponed{$found} =
9589 "break $offset if $dbline{$line}";
9593 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
9595 } ## end for $line (keys %dbline)
9596 } ## end for (@hard)
9598 # Save the other things that don't need to be
9600 set_list( "PERLDB_POSTPONE", %postponed );
9601 set_list( "PERLDB_PRETYPE", @$pretype );
9602 set_list( "PERLDB_PRE", @$pre );
9603 set_list( "PERLDB_POST", @$post );
9604 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9606 # We are officially restarting.
9607 $ENV{PERLDB_RESTART} = 1;
9609 # We are junking all child debuggers.
9610 delete $ENV{PERLDB_PIDS}; # Restore ini state
9612 # Set this back to the initial pid.
9613 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9617 After all the debugger status has been saved, we take the command we built up
9618 and then return it, so we can C<exec()> it. The debugger will spot the
9619 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9620 from the environment.
9624 # And run Perl again. Add the "-d" flag, all the
9625 # flags we built up, the script (whether a one-liner
9626 # or a file), add on the -emacs flag for a slave editor,
9627 # and then the old arguments.
9629 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9635 =head1 END PROCESSING - THE C<END> BLOCK
9637 Come here at the very end of processing. We want to go into a
9638 loop where we allow the user to enter commands and interact with the
9639 debugger, but we don't want anything else to execute.
9641 First we set the C<$finished> variable, so that some commands that
9642 shouldn't be run after the end of program quit working.
9644 We then figure out whether we're truly done (as in the user entered a C<q>
9645 command, or we finished execution while running nonstop). If we aren't,
9646 we set C<$single> to 1 (causing the debugger to get control again).
9648 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9649 message and returns control to the debugger. Repeat.
9651 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9652 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9653 break, run to completion.).
9658 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9659 $fall_off_end = 1 unless $inhibit_exit;
9661 # Do not stop in at_exit() and destructors on exit:
9662 if ($fall_off_end or $runnonstop) {
9666 DB::fake::at_exit();
9670 =head1 PRE-5.8 COMMANDS
9672 Some of the commands changed function quite a bit in the 5.8 command
9673 realignment, so much so that the old code had to be replaced completely.
9674 Because we wanted to retain the option of being able to go back to the
9675 former command set, we moved the old code off to this section.
9677 There's an awful lot of duplicated code here. We've duplicated the
9678 comments to keep things clear.
9682 Does nothing. Used to I<turn off> commands.
9686 sub cmd_pre580_null {
9691 =head2 Old C<a> command.
9693 This version added actions if you supplied them, and deleted them
9702 # Argument supplied. Add the action.
9703 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9705 # If the line isn't there, use the current line.
9706 my $i = $1 || $line;
9709 # If there is an action ...
9712 # ... but the line isn't breakable, skip it.
9713 if ( $dbline[$i] == 0 ) {
9714 print $OUT "Line $i may not have an action.\n";
9718 # ... and the line is breakable:
9719 # Mark that there's an action in this file.
9720 $had_breakpoints{$filename} |= 2;
9722 # Delete any current action.
9723 $dbline{$i} =~ s/\0[^\0]*//;
9725 # Add the new action, continuing the line as needed.
9726 $dbline{$i} .= "\0" . action($j);
9728 } ## end if (length $j)
9730 # No action supplied.
9733 # Delete the action.
9734 $dbline{$i} =~ s/\0[^\0]*//;
9736 # Mark as having no break or action if nothing's left.
9737 delete $dbline{$i} if $dbline{$i} eq '';
9739 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9740 } ## end sub cmd_pre580_a
9742 =head2 Old C<b> command
9754 if ( $cmd =~ /^load\b\s*(.*)/ ) {
9760 # b compile|postpone <some sub> [<condition>]
9761 # The interpreter actually traps this one for us; we just put the
9762 # necessary condition in the %postponed hash.
9763 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
9765 # Capture the condition if there is one. Make it true if none.
9766 my $cond = length $3 ? $3 : '1';
9768 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
9769 # if it was 'compile'.
9770 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
9772 # De-Perl4-ify the name - ' separators to ::.
9773 $subname =~ s/\'/::/g;
9775 # Qualify it into the current package unless it's already qualified.
9776 $subname = "${package}::" . $subname
9777 unless $subname =~ /::/;
9779 # Add main if it starts with ::.
9780 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
9782 # Save the break type for this sub.
9783 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
9784 } ## end elsif ($cmd =~ ...
9786 # b <sub name> [<condition>]
9787 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
9789 my $cond = length $2 ? $2 : '1';
9790 &cmd_b_sub( $subname, $cond );
9792 # b <line> [<condition>].
9793 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9794 my $i = $1 || $dbline;
9795 my $cond = length $2 ? $2 : '1';
9796 &cmd_b_line( $i, $cond );
9798 } ## end sub cmd_pre580_b
9800 =head2 Old C<D> command.
9802 Delete all breakpoints unconditionally.
9809 if ( $cmd =~ /^\s*$/ ) {
9810 print $OUT "Deleting all breakpoints...\n";
9812 # %had_breakpoints lists every file that had at least one
9815 for $file ( keys %had_breakpoints ) {
9817 # Switch to the desired file temporarily.
9818 local *dbline = $main::{ '_<' . $file };
9823 # For all lines in this file ...
9824 for my $i (1 .. $max) {
9826 # If there's a breakpoint or action on this line ...
9827 if ( defined $dbline{$i} ) {
9829 # ... remove the breakpoint.
9830 $dbline{$i} =~ s/^[^\0]+//;
9831 if ( $dbline{$i} =~ s/^\0?$// ) {
9833 # Remove the entry altogether if no action is there.
9836 } ## end if (defined $dbline{$i...
9837 } ## end for my $i (1 .. $max)
9839 # If, after we turn off the "there were breakpoints in this file"
9840 # bit, the entry in %had_breakpoints for this file is zero,
9841 # we should remove this file from the hash.
9842 if ( not $had_breakpoints{$file} &= ~1 ) {
9843 delete $had_breakpoints{$file};
9845 } ## end for $file (keys %had_breakpoints)
9847 # Kill off all the other breakpoints that are waiting for files that
9848 # haven't been loaded yet.
9850 undef %postponed_file;
9851 undef %break_on_load;
9852 } ## end if ($cmd =~ /^\s*$/)
9853 } ## end sub cmd_pre580_D
9855 =head2 Old C<h> command
9857 Print help. Defaults to printing the long-form help; the 5.8 version
9858 prints the summary by default.
9866 # Print the *right* help, long format.
9867 if ( $cmd =~ /^\s*$/ ) {
9868 print_help($pre580_help);
9871 # 'h h' - explicitly-requested summary.
9872 elsif ( $cmd =~ /^h\s*/ ) {
9873 print_help($pre580_summary);
9876 # Find and print a command's help.
9877 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
9878 my $asked = $1; # for proper errmsg
9879 my $qasked = quotemeta($asked); # for searching
9880 # XXX: finds CR but not <CR>
9884 (?:[IB]<) # Optional markup
9885 $qasked # The command name
9892 ( # The command help:
9894 (?:[IB]<) # Optional markup
9895 $qasked # The command name
9896 ([\s\S]*?) # Lines starting with tabs
9900 ) # Line not starting with space
9901 # (Next command's help)
9905 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
9909 print_help("B<$asked> is not a debugger command.\n");
9911 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
9912 } ## end sub cmd_pre580_h
9914 =head2 Old C<W> command
9916 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
9924 # Delete all watch expressions.
9925 if ( $cmd =~ /^$/ ) {
9927 # No watching is going on.
9930 # Kill all the watch expressions and values.
9931 @to_watch = @old_watch = ();
9934 # Add a watch expression.
9935 elsif ( $cmd =~ /^(.*)/s ) {
9937 # add it to the list to be watched.
9940 # Get the current value of the expression.
9941 # Doesn't handle expressions returning list values!
9943 my ($val) = DB::eval();
9944 $val = ( defined $val ) ? "'$val'" : 'undef';
9947 push @old_watch, $val;
9949 # We're watching stuff.
9952 } ## end elsif ($cmd =~ /^(.*)/s)
9953 } ## end sub cmd_pre580_W
9955 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
9957 The debugger used to have a bunch of nearly-identical code to handle
9958 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
9959 C<cmd_prepost> unify all this into one set of code to handle the
9960 appropriate actions.
9962 =head2 C<cmd_pre590_prepost>
9964 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
9965 do something destructive. In pre 5.8 debuggers, the default action was to
9966 delete all the actions.
9970 sub cmd_pre590_prepost {
9972 my $line = shift || '*';
9975 return &cmd_prepost( $cmd, $line, $dbline );
9976 } ## end sub cmd_pre590_prepost
9978 =head2 C<cmd_prepost>
9980 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
9981 Since the lists of actions are all held in arrays that are pointed to by
9982 references anyway, all we have to do is pick the right array reference and
9983 then use generic code to all, delete, or list actions.
9990 # No action supplied defaults to 'list'.
9991 my $line = shift || '?';
9993 # Figure out what to put in the prompt.
9996 # Make sure we have some array or another to address later.
9997 # This means that if ssome reason the tests fail, we won't be
9998 # trying to stash actions or delete them from the wrong place.
10001 # < - Perl code to run before prompt.
10002 if ( $cmd =~ /^\</o ) {
10003 $which = 'pre-perl';
10007 # > - Perl code to run after prompt.
10008 elsif ( $cmd =~ /^\>/o ) {
10009 $which = 'post-perl';
10013 # { - first check for properly-balanced braces.
10014 elsif ( $cmd =~ /^\{/o ) {
10015 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
10017 "$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n";
10020 # Properly balanced. Pre-prompt debugger actions.
10022 $which = 'pre-debugger';
10025 } ## end elsif ( $cmd =~ /^\{/o )
10027 # Did we find something that makes sense?
10029 print $OUT "Confused by command: $cmd\n";
10036 if ( $line =~ /^\s*\?\s*$/o ) {
10039 # Nothing there. Complain.
10040 print $OUT "No $which actions.\n";
10044 # List the actions in the selected list.
10045 print $OUT "$which commands:\n";
10046 foreach my $action (@$aref) {
10047 print $OUT "\t$cmd -- $action\n";
10050 } ## end if ( $line =~ /^\s*\?\s*$/o)
10052 # Might be a delete.
10054 if ( length($cmd) == 1 ) {
10055 if ( $line =~ /^\s*\*\s*$/o ) {
10057 # It's a delete. Get rid of the old actions in the
10060 print $OUT "All $cmd actions cleared.\n";
10064 # Replace all the actions. (This is a <, >, or {).
10065 @$aref = action($line);
10067 } ## end if ( length($cmd) == 1)
10068 elsif ( length($cmd) == 2 ) {
10070 # Add the action to the line. (This is a <<, >>, or {{).
10071 push @$aref, action($line);
10075 # <<<, >>>>, {{{{{{ ... something not a command.
10077 "Confused by strange length of $which command($cmd)...\n";
10079 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
10081 } ## end sub cmd_prepost
10085 Contains the C<at_exit> routine that the debugger uses to issue the
10086 C<Debugged program terminated ...> message after the program completes. See
10087 the C<END> block documentation for more details.
10094 "Debugged program terminated. Use 'q' to quit or 'R' to restart.";
10097 package DB; # Do not trace this 1; below!
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