4 perl5db.pl - the perl debugger
8 perl -d your_Perl_script
12 C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
13 you invoke a script with C<perl -d>. This documentation tries to outline the
14 structure and services provided by C<perl5db.pl>, and to describe how you
19 The debugger can look pretty forbidding to many Perl programmers. There are
20 a number of reasons for this, many stemming out of the debugger's history.
22 When the debugger was first written, Perl didn't have a lot of its nicer
23 features - no references, no lexical variables, no closures, no object-oriented
24 programming. So a lot of the things one would normally have done using such
25 features was done using global variables, globs and the C<local()> operator
28 Some of these have survived into the current debugger; a few of the more
29 interesting and still-useful idioms are noted in this section, along with notes
30 on the comments themselves.
32 =head2 Why not use more lexicals?
34 Experienced Perl programmers will note that the debugger code tends to use
35 mostly package globals rather than lexically-scoped variables. This is done
36 to allow a significant amount of control of the debugger from outside the
39 Unfortunately, though the variables are accessible, they're not well
40 documented, so it's generally been a decision that hasn't made a lot of
41 difference to most users. Where appropriate, comments have been added to
42 make variables more accessible and usable, with the understanding that these
43 I<are> debugger internals, and are therefore subject to change. Future
44 development should probably attempt to replace the globals with a well-defined
45 API, but for now, the variables are what we've got.
47 =head2 Automated variable stacking via C<local()>
49 As you may recall from reading C<perlfunc>, the C<local()> operator makes a
50 temporary copy of a variable in the current scope. When the scope ends, the
51 old copy is restored. This is often used in the debugger to handle the
52 automatic stacking of variables during recursive calls:
57 # Do some stuff, then ...
61 What happens is that on entry to the subroutine, C<$some_global> is localized,
62 then altered. When the subroutine returns, Perl automatically undoes the
63 localization, restoring the previous value. Voila, automatic stack management.
65 The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
66 which lets the debugger get control inside of C<eval>'ed code. The debugger
67 localizes a saved copy of C<$@> inside the subroutine, which allows it to
68 keep C<$@> safe until it C<DB::eval> returns, at which point the previous
69 value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
70 track of C<$@> inside C<eval>s which C<eval> other C<eval's>.
72 In any case, watch for this pattern. It occurs fairly often.
76 This is used to cleverly reverse the sense of a logical test depending on
77 the value of an auxiliary variable. For instance, the debugger's C<S>
78 (search for subroutines by pattern) allows you to negate the pattern
81 # Find all non-'foo' subs:
84 Boolean algebra states that the truth table for XOR looks like this:
90 (! not present and no match) --> false, don't print
94 (! not present and matches) --> true, print
98 (! present and no match) --> true, print
102 (! present and matches) --> false, don't print
106 As you can see, the first pair applies when C<!> isn't supplied, and
107 the second pair applies when it is. The XOR simply allows us to
108 compact a more complicated if-then-elseif-else into a more elegant
109 (but perhaps overly clever) single test. After all, it needed this
112 =head2 FLAGS, FLAGS, FLAGS
114 There is a certain C programming legacy in the debugger. Some variables,
115 such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed
116 of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
117 of state to be stored independently in a single scalar.
123 is checking to see if the appropriate bit is on. Since each bit can be
124 "addressed" independently in this way, C<$scalar> is acting sort of like
125 an array of bits. Obviously, since the contents of C<$scalar> are just a
126 bit-pattern, we can save and restore it easily (it will just look like
129 The problem, is of course, that this tends to leave magic numbers scattered
130 all over your program whenever a bit is set, cleared, or checked. So why do
137 First, doing an arithmetical or bitwise operation on a scalar is
138 just about the fastest thing you can do in Perl: C<use constant> actually
139 creates a subroutine call, and array and hash lookups are much slower. Is
140 this over-optimization at the expense of readability? Possibly, but the
141 debugger accesses these variables a I<lot>. Any rewrite of the code will
142 probably have to benchmark alternate implementations and see which is the
143 best balance of readability and speed, and then document how it actually
148 Second, it's very easy to serialize a scalar number. This is done in
149 the restart code; the debugger state variables are saved in C<%ENV> and then
150 restored when the debugger is restarted. Having them be just numbers makes
155 Third, some of these variables are being shared with the Perl core
156 smack in the middle of the interpreter's execution loop. It's much faster for
157 a C program (like the interpreter) to check a bit in a scalar than to access
158 several different variables (or a Perl array).
162 =head2 What are those C<XXX> comments for?
164 Any comment containing C<XXX> means that the comment is either somewhat
165 speculative - it's not exactly clear what a given variable or chunk of
166 code is doing, or that it is incomplete - the basics may be clear, but the
167 subtleties are not completely documented.
169 Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
171 =head1 DATA STRUCTURES MAINTAINED BY CORE
173 There are a number of special data structures provided to the debugger by
174 the Perl interpreter.
176 The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline>
177 via glob assignment) contains the text from C<$filename>, with each
178 element corresponding to a single line of C<$filename>. Additionally,
179 breakable lines will be dualvars with the numeric component being the
180 memory address of a COP node. Non-breakable lines are dualvar to 0.
182 The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
183 assignment) contains breakpoints and actions. The keys are line numbers;
184 you can set individual values, but not the whole hash. The Perl interpreter
185 uses this hash to determine where breakpoints have been set. Any true value is
186 considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
187 Values are magical in numeric context: 1 if the line is breakable, 0 if not.
189 The scalar C<${"_<$filename"}> simply contains the string C<$filename>.
190 This is also the case for evaluated strings that contain subroutines, or
191 which are currently being executed. The $filename for C<eval>ed strings looks
194 =head1 DEBUGGER STARTUP
196 When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
197 non-interactive sessions, C<.perldb> for interactive ones) that can set a number
198 of options. In addition, this file may define a subroutine C<&afterinit>
199 that will be executed (in the debugger's context) after the debugger has
202 Next, it checks the C<PERLDB_OPTS> environment variable and treats its
203 contents as the argument of a C<o> command in the debugger.
205 =head2 STARTUP-ONLY OPTIONS
207 The following options can only be specified at startup.
208 To set them in your rcfile, add a call to
209 C<&parse_options("optionName=new_value")>.
215 the TTY to use for debugging i/o.
219 if set, goes in NonStop mode. On interrupt, if TTY is not set,
220 uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
221 Term::Rendezvous. Current variant is to have the name of TTY in this
226 if false, a dummy ReadLine is used, so you can debug
227 ReadLine applications.
231 if true, no i/o is performed until interrupt.
235 file or pipe to print line number info to. If it is a
236 pipe, a short "emacs like" message is used.
240 host:port to connect to on remote host for remote debugging.
244 file to store session history to. There is no default and so no
245 history file is written unless this variable is explicitly set.
249 number of commands to store to the file specified in C<HistFile>.
256 &parse_options("NonStop=1 LineInfo=db.out");
257 sub afterinit { $trace = 1; }
259 The script will run without human intervention, putting trace
260 information into C<db.out>. (If you interrupt it, you had better
261 reset C<LineInfo> to something I<interactive>!)
263 =head1 INTERNALS DESCRIPTION
265 =head2 DEBUGGER INTERFACE VARIABLES
267 Perl supplies the values for C<%sub>. It effectively inserts
268 a C<&DB::DB();> in front of each place that can have a
269 breakpoint. At each subroutine call, it calls C<&DB::sub> with
270 C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
271 {require 'perl5db.pl'}> before the first line.
273 After each C<require>d file is compiled, but before it is executed, a
274 call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
275 is the expanded name of the C<require>d file (as found via C<%INC>).
277 =head3 IMPORTANT INTERNAL VARIABLES
281 Used to control when the debugger will attempt to acquire another TTY to be
286 =item * 1 - on C<fork()>
288 =item * 2 - debugger is started inside debugger
290 =item * 4 - on startup
296 The value -2 indicates that no return value should be printed.
297 Any other positive value causes C<DB::sub> to print return values.
301 The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
302 contents of C<@_> when C<DB::eval> is called.
306 Determines what messages (if any) will get printed when a subroutine (or eval)
307 is entered or exited.
311 =item * 0 - No enter/exit messages
313 =item * 1 - Print I<entering> messages on subroutine entry
315 =item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
317 =item * 4 - Extended messages: C<< <in|out> I<context>=I<fully-qualified sub name> from I<file>:I<line> >>. If no other flag is on, acts like 1+4.
319 =item * 8 - Adds parameter information to messages, and overloaded stringify and tied FETCH is enabled on the printed arguments. Ignored if C<4> is not on.
321 =item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is is not on.
325 To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
326 The debugger internally juggles the value of C<$frame> during execution to
327 protect external modules that the debugger uses from getting traced.
331 Tracks current debugger nesting level. Used to figure out how many
332 C<E<lt>E<gt>> pairs to surround the line number with when the debugger
333 outputs a prompt. Also used to help determine if the program has finished
334 during command parsing.
336 =head4 C<$onetimeDump>
338 Controls what (if anything) C<DB::eval()> will print after evaluating an
343 =item * C<undef> - don't print anything
345 =item * C<dump> - use C<dumpvar.pl> to display the value returned
347 =item * C<methods> - print the methods callable on the first item returned
351 =head4 C<$onetimeDumpDepth>
353 Controls how far down C<dumpvar.pl> will go before printing C<...> while
354 dumping a structure. Numeric. If C<undef>, print all levels.
358 Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
359 which is called before every statement, checks this and puts the user into
360 command mode if it finds C<$signal> set to a true value.
364 Controls behavior during single-stepping. Stacked in C<@stack> on entry to
365 each subroutine; popped again at the end of each subroutine.
369 =item * 0 - run continuously.
371 =item * 1 - single-step, go into subs. The C<s> command.
373 =item * 2 - single-step, don't go into subs. The C<n> command.
375 =item * 4 - print current sub depth (turned on to force this when C<too much
382 Controls the output of trace information.
386 =item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
388 =item * 2 - watch expressions are active
390 =item * 4 - user defined a C<watchfunction()> in C<afterinit()>
394 =head4 C<$slave_editor>
396 1 if C<LINEINFO> was directed to a pipe; 0 otherwise.
400 Stack of filehandles that C<DB::readline()> will read commands from.
401 Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
405 Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
406 supplied by the Perl interpreter to the debugger. Contains the source.
410 Previous values of watch expressions. First set when the expression is
411 entered; reset whenever the watch expression changes.
415 Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
416 so that the debugger can substitute safe values while it's running, and
417 restore them when it returns control.
421 Saves the current value of C<$single> on entry to a subroutine.
422 Manipulated by the C<c> command to turn off tracing in all subs above the
427 The 'watch' expressions: to be evaluated before each line is executed.
431 The typeahead buffer, used by C<DB::readline>.
435 Command aliases. Stored as character strings to be substituted for a command
438 =head4 C<%break_on_load>
440 Keys are file names, values are 1 (break when this file is loaded) or undef
441 (don't break when it is loaded).
445 Keys are line numbers, values are C<condition\0action>. If used in numeric
446 context, values are 0 if not breakable, 1 if breakable, no matter what is
447 in the actual hash entry.
449 =head4 C<%had_breakpoints>
451 Keys are file names; values are bitfields:
455 =item * 1 - file has a breakpoint in it.
457 =item * 2 - file has an action in it.
461 A zero or undefined value means this file has neither.
465 Stores the debugger options. These are character string values.
469 Saves breakpoints for code that hasn't been compiled yet.
470 Keys are subroutine names, values are:
474 =item * C<compile> - break when this sub is compiled
476 =item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
480 =head4 C<%postponed_file>
482 This hash keeps track of breakpoints that need to be set for files that have
483 not yet been compiled. Keys are filenames; values are references to hashes.
484 Each of these hashes is keyed by line number, and its values are breakpoint
485 definitions (C<condition\0action>).
487 =head1 DEBUGGER INITIALIZATION
489 The debugger's initialization actually jumps all over the place inside this
490 package. This is because there are several BEGIN blocks (which of course
491 execute immediately) spread through the code. Why is that?
493 The debugger needs to be able to change some things and set some things up
494 before the debugger code is compiled; most notably, the C<$deep> variable that
495 C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
496 debugger has to turn off warnings while the debugger code is compiled, but then
497 restore them to their original setting before the program being debugged begins
500 The first C<BEGIN> block simply turns off warnings by saving the current
501 setting of C<$^W> and then setting it to zero. The second one initializes
502 the debugger variables that are needed before the debugger begins executing.
503 The third one puts C<$^X> back to its former value.
505 We'll detail the second C<BEGIN> block later; just remember that if you need
506 to initialize something before the debugger starts really executing, that's
515 BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
519 $^V =~ /^v(\d+\.\d+)/;
520 feature->import(":$1");
523 # Debugger for Perl 5.00x; perl5db.pl patch level:
524 use vars qw($VERSION $header);
526 $VERSION = '1.39_05';
528 $header = "perl5db.pl version $VERSION";
530 =head1 DEBUGGER ROUTINES
534 This function replaces straight C<eval()> inside the debugger; it simplifies
535 the process of evaluating code in the user's context.
537 The code to be evaluated is passed via the package global variable
538 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
540 Before we do the C<eval()>, we preserve the current settings of C<$trace>,
541 C<$single>, C<$^D> and C<$usercontext>. The latter contains the
542 preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
543 user's current package, grabbed when C<DB::DB> got control. This causes the
544 proper context to be used when the eval is actually done. Afterward, we
545 restore C<$trace>, C<$single>, and C<$^D>.
547 Next we need to handle C<$@> without getting confused. We save C<$@> in a
548 local lexical, localize C<$saved[0]> (which is where C<save()> will put
549 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
550 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
551 considered sane by the debugger. If there was an C<eval()> error, we print
552 it on the debugger's output. If C<$onetimedump> is defined, we call
553 C<dumpit> if it's set to 'dump', or C<methods> if it's set to
554 'methods'. Setting it to something else causes the debugger to do the eval
555 but not print the result - handy if you want to do something else with it
556 (the "watch expressions" code does this to get the value of the watch
557 expression but not show it unless it matters).
559 In any case, we then return the list of output from C<eval> to the caller,
560 and unwinding restores the former version of C<$@> in C<@saved> as well
561 (the localization of C<$saved[0]> goes away at the end of this scope).
563 =head3 Parameters and variables influencing execution of DB::eval()
565 C<DB::eval> isn't parameterized in the standard way; this is to keep the
566 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
567 The variables listed below influence C<DB::eval()>'s execution directly.
571 =item C<$evalarg> - the thing to actually be eval'ed
573 =item C<$trace> - Current state of execution tracing
575 =item C<$single> - Current state of single-stepping
577 =item C<$onetimeDump> - what is to be displayed after the evaluation
579 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
583 The following variables are altered by C<DB::eval()> during its execution. They
584 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
588 =item C<@res> - used to capture output from actual C<eval>.
590 =item C<$otrace> - saved value of C<$trace>.
592 =item C<$osingle> - saved value of C<$single>.
594 =item C<$od> - saved value of C<$^D>.
596 =item C<$saved[0]> - saved value of C<$@>.
598 =item $\ - for output of C<$@> if there is an evaluation error.
602 =head3 The problem of lexicals
604 The context of C<DB::eval()> presents us with some problems. Obviously,
605 we want to be 'sandboxed' away from the debugger's internals when we do
606 the eval, but we need some way to control how punctuation variables and
607 debugger globals are used.
609 We can't use local, because the code inside C<DB::eval> can see localized
610 variables; and we can't use C<my> either for the same reason. The code
611 in this routine compromises and uses C<my>.
613 After this routine is over, we don't have user code executing in the debugger's
614 context, so we can use C<my> freely.
618 ############################################## Begin lexical danger zone
620 # 'my' variables used here could leak into (that is, be visible in)
621 # the context that the code being evaluated is executing in. This means that
622 # the code could modify the debugger's variables.
624 # Fiddling with the debugger's context could be Bad. We insulate things as
689 # Used to save @ARGV and extract any debugger-related flags.
692 # Used to prevent multiple entries to diesignal()
693 # (if for instance diesignal() itself dies)
696 # Used to prevent the debugger from running nonstop
700 sub _calc_usercontext {
703 # Cancel strict completely for the evaluated code, so the code
704 # the user evaluates won't be affected by it. (Shlomi Fish)
705 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
706 . "package $package;"; # this won't let them modify, alas
711 # 'my' would make it visible from user code
712 # but so does local! --tchrist
713 # Remember: this localizes @DB::res, not @main::res.
717 # Try to keep the user code from messing with us. Save these so that
718 # even if the eval'ed code changes them, we can put them back again.
719 # Needed because the user could refer directly to the debugger's
720 # package globals (and any 'my' variables in this containing scope)
721 # inside the eval(), and we want to try to stay safe.
722 local $otrace = $trace;
723 local $osingle = $single;
726 # Untaint the incoming eval() argument.
727 { ($evalarg) = $evalarg =~ /(.*)/s; }
729 # $usercontext built in DB::DB near the comment
730 # "set up the context for DB::eval ..."
731 # Evaluate and save any results.
732 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
734 # Restore those old values.
740 # Save the current value of $@, and preserve it in the debugger's copy
741 # of the saved precious globals.
744 # Since we're only saving $@, we only have to localize the array element
745 # that it will be stored in.
746 local $saved[0]; # Preserve the old value of $@
749 # Now see whether we need to report an error back to the user.
755 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
756 # are package globals.
757 elsif ($onetimeDump) {
758 if ( $onetimeDump eq 'dump' ) {
759 local $option{dumpDepth} = $onetimedumpDepth
760 if defined $onetimedumpDepth;
761 dumpit( $OUT, \@res );
763 elsif ( $onetimeDump eq 'methods' ) {
766 } ## end elsif ($onetimeDump)
770 ############################################## End lexical danger zone
772 # After this point it is safe to introduce lexicals.
773 # The code being debugged will be executing in its own context, and
774 # can't see the inside of the debugger.
776 # However, one should not overdo it: leave as much control from outside as
777 # possible. If you make something a lexical, it's not going to be addressable
778 # from outside the debugger even if you know its name.
780 # This file is automatically included if you do perl -d.
781 # It's probably not useful to include this yourself.
783 # Before venturing further into these twisty passages, it is
784 # wise to read the perldebguts man page or risk the ire of dragons.
786 # (It should be noted that perldebguts will tell you a lot about
787 # the underlying mechanics of how the debugger interfaces into the
788 # Perl interpreter, but not a lot about the debugger itself. The new
789 # comments in this code try to address this problem.)
791 # Note that no subroutine call is possible until &DB::sub is defined
792 # (for subroutines defined outside of the package DB). In fact the same is
793 # true if $deep is not defined.
795 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
797 # modified Perl debugger, to be run from Emacs in perldb-mode
798 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
799 # Johan Vromans -- upgrade to 4.0 pl 10
800 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
801 ########################################################################
803 =head1 DEBUGGER INITIALIZATION
805 The debugger starts up in phases.
809 First, it initializes the environment it wants to run in: turning off
810 warnings during its own compilation, defining variables which it will need
811 to avoid warnings later, setting itself up to not exit when the program
812 terminates, and defaulting to printing return values for the C<r> command.
816 # Needed for the statement after exec():
818 # This BEGIN block is simply used to switch off warnings during debugger
819 # compilation. Probably it would be better practice to fix the warnings,
820 # but this is how it's done at the moment.
825 } # Switch compilation warnings off until another BEGIN.
827 local ($^W) = 0; # Switch run-time warnings off during init.
829 =head2 THREADS SUPPORT
831 If we are running under a threaded Perl, we require threads and threads::shared
832 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
833 threaded debugger control. C<-dt> can also be used to set this.
835 Each new thread will be announced and the debugger prompt will always inform
836 you of each new thread created. It will also indicate the thread id in which
837 we are currently running within the prompt like this:
841 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
842 command prompt. The prompt will show: C<[0]> when running under threads, but
843 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
845 While running under threads, when you set or delete a breakpoint (etc.), this
846 will apply to all threads, not just the currently running one. When you are
847 in a currently executing thread, you will stay there until it completes. With
848 the current implementation it is not currently possible to hop from one thread
851 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
853 Note that threading support was built into the debugger as of Perl version
854 C<5.8.6> and debugger version C<1.2.8>.
859 # ensure we can share our non-threaded variables or no-op
860 if ($ENV{PERL5DB_THREADED}) {
862 require threads::shared;
863 import threads::shared qw(share);
867 print "Threads support enabled\n";
869 *share = sub(\[$@%]) {};
873 # These variables control the execution of 'dumpvar.pl'.
888 # used to control die() reporting in diesignal()
891 use vars qw($CarpLevel);
894 # without threads, $filename is not defined until DB::DB is called
895 share($main::{'_<'.$filename}) if defined $filename;
897 # Command-line + PERLLIB:
898 # Save the contents of @INC before they are modified elsewhere.
901 # This was an attempt to clear out the previous values of various
902 # trapped errors. Apparently it didn't help. XXX More info needed!
903 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
905 # We set these variables to safe values. We don't want to blindly turn
906 # off warnings, because other packages may still want them.
907 $trace = $signal = $single = 0; # Uninitialized warning suppression
908 # (local $^W cannot help - other packages!).
910 # Default to not exiting when program finishes; print the return
911 # value when the 'r' command is used to return from a subroutine.
912 $inhibit_exit = $option{PrintRet} = 1;
914 use vars qw($trace_to_depth);
916 # Default to 1E9 so it won't be limited to a certain recursion depth.
917 $trace_to_depth = 1E9;
919 =head1 OPTION PROCESSING
921 The debugger's options are actually spread out over the debugger itself and
922 C<dumpvar.pl>; some of these are variables to be set, while others are
923 subs to be called with a value. To try to make this a little easier to
924 manage, the debugger uses a few data structures to define what options
925 are legal and how they are to be processed.
927 First, the C<@options> array defines the I<names> of all the options that
933 CommandSet HistFile HistSize
934 hashDepth arrayDepth dumpDepth
935 DumpDBFiles DumpPackages DumpReused
936 compactDump veryCompact quote
937 HighBit undefPrint globPrint
938 PrintRet UsageOnly frame
940 ReadLine NonStop LineInfo
941 maxTraceLen recallCommand ShellBang
942 pager tkRunning ornaments
943 signalLevel warnLevel dieLevel
944 inhibit_exit ImmediateStop bareStringify
945 CreateTTY RemotePort windowSize
949 @RememberOnROptions = qw(DollarCaretP);
953 Second, C<optionVars> lists the variables that each option uses to save its
958 use vars qw(%optionVars);
961 hashDepth => \$dumpvar::hashDepth,
962 arrayDepth => \$dumpvar::arrayDepth,
963 CommandSet => \$CommandSet,
964 DumpDBFiles => \$dumpvar::dumpDBFiles,
965 DumpPackages => \$dumpvar::dumpPackages,
966 DumpReused => \$dumpvar::dumpReused,
967 HighBit => \$dumpvar::quoteHighBit,
968 undefPrint => \$dumpvar::printUndef,
969 globPrint => \$dumpvar::globPrint,
970 UsageOnly => \$dumpvar::usageOnly,
971 CreateTTY => \$CreateTTY,
972 bareStringify => \$dumpvar::bareStringify,
974 AutoTrace => \$trace,
975 inhibit_exit => \$inhibit_exit,
976 maxTraceLen => \$maxtrace,
977 ImmediateStop => \$ImmediateStop,
978 RemotePort => \$remoteport,
979 windowSize => \$window,
980 HistFile => \$histfile,
981 HistSize => \$histsize,
986 Third, C<%optionAction> defines the subroutine to be called to process each
991 use vars qw(%optionAction);
994 compactDump => \&dumpvar::compactDump,
995 veryCompact => \&dumpvar::veryCompact,
996 quote => \&dumpvar::quote,
999 ReadLine => \&ReadLine,
1000 NonStop => \&NonStop,
1001 LineInfo => \&LineInfo,
1002 recallCommand => \&recallCommand,
1003 ShellBang => \&shellBang,
1005 signalLevel => \&signalLevel,
1006 warnLevel => \&warnLevel,
1007 dieLevel => \&dieLevel,
1008 tkRunning => \&tkRunning,
1009 ornaments => \&ornaments,
1010 RemotePort => \&RemotePort,
1011 DollarCaretP => \&DollarCaretP,
1016 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1021 # Note that this list is not complete: several options not listed here
1022 # actually require that dumpvar.pl be loaded for them to work, but are
1023 # not in the table. A subsequent patch will correct this problem; for
1024 # the moment, we're just recommenting, and we are NOT going to change
1026 use vars qw(%optionRequire);
1029 compactDump => 'dumpvar.pl',
1030 veryCompact => 'dumpvar.pl',
1031 quote => 'dumpvar.pl',
1036 There are a number of initialization-related variables which can be set
1037 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1038 variable. These are:
1042 =item C<$rl> - readline control XXX needs more explanation
1044 =item C<$warnLevel> - whether or not debugger takes over warning handling
1046 =item C<$dieLevel> - whether or not debugger takes over die handling
1048 =item C<$signalLevel> - whether or not debugger takes over signal handling
1050 =item C<$pre> - preprompt actions (array reference)
1052 =item C<$post> - postprompt actions (array reference)
1056 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1058 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1064 # These guys may be defined in $ENV{PERL5DB} :
1065 $rl = 1 unless defined $rl;
1066 $warnLevel = 1 unless defined $warnLevel;
1067 $dieLevel = 1 unless defined $dieLevel;
1068 $signalLevel = 1 unless defined $signalLevel;
1069 $pre = [] unless defined $pre;
1070 $post = [] unless defined $post;
1071 $pretype = [] unless defined $pretype;
1072 $CreateTTY = 3 unless defined $CreateTTY;
1073 $CommandSet = '580' unless defined $CommandSet;
1078 share($signalLevel);
1088 The default C<die>, C<warn>, and C<signal> handlers are set up.
1092 warnLevel($warnLevel);
1093 dieLevel($dieLevel);
1094 signalLevel($signalLevel);
1098 The pager to be used is needed next. We try to get it from the
1099 environment first. If it's not defined there, we try to find it in
1100 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1101 then call the C<pager()> function to save the pager name.
1105 # This routine makes sure $pager is set up so that '|' can use it.
1108 # If PAGER is defined in the environment, use it.
1112 # If not, see if Config.pm defines it.
1113 : eval { require Config }
1114 && defined $Config::Config{pager}
1115 ? $Config::Config{pager}
1117 # If not, fall back to 'more'.
1120 unless defined $pager;
1124 We set up the command to be used to access the man pages, the command
1125 recall character (C<!> unless otherwise defined) and the shell escape
1126 character (C<!> unless otherwise defined). Yes, these do conflict, and
1127 neither works in the debugger at the moment.
1133 # Set up defaults for command recall and shell escape (note:
1134 # these currently don't work in linemode debugging).
1135 recallCommand("!") unless defined $prc;
1136 shellBang("!") unless defined $psh;
1140 We then set up the gigantic string containing the debugger help.
1141 We also set the limit on the number of arguments we'll display during a
1148 # If we didn't get a default for the length of eval/stack trace args,
1150 $maxtrace = 400 unless defined $maxtrace;
1152 =head2 SETTING UP THE DEBUGGER GREETING
1154 The debugger I<greeting> helps to inform the user how many debuggers are
1155 running, and whether the current debugger is the primary or a child.
1157 If we are the primary, we just hang onto our pid so we'll have it when
1158 or if we start a child debugger. If we are a child, we'll set things up
1159 so we'll have a unique greeting and so the parent will give us our own
1162 We save the current contents of the C<PERLDB_PIDS> environment variable
1163 because we mess around with it. We'll also need to hang onto it because
1164 we'll need it if we restart.
1166 Child debuggers make a label out of the current PID structure recorded in
1167 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1168 yet so the parent will give them one later via C<resetterm()>.
1172 # Save the current contents of the environment; we're about to
1173 # much with it. We'll need this if we have to restart.
1174 use vars qw($ini_pids);
1175 $ini_pids = $ENV{PERLDB_PIDS};
1177 use vars qw ($pids $term_pid);
1179 if ( defined $ENV{PERLDB_PIDS} ) {
1181 # We're a child. Make us a label out of the current PID structure
1182 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1183 # a term yet so the parent will give us one later via resetterm().
1185 my $env_pids = $ENV{PERLDB_PIDS};
1186 $pids = "[$env_pids]";
1188 # Unless we are on OpenVMS, all programs under the DCL shell run under
1191 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1195 $ENV{PERLDB_PIDS} .= "->$$";
1199 } ## end if (defined $ENV{PERLDB_PIDS...
1202 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1203 # child debugger, and mark us as the parent, so we'll know to set up
1204 # more TTY's is we have to.
1205 $ENV{PERLDB_PIDS} = "$$";
1210 use vars qw($pidprompt);
1213 # Sets up $emacs as a synonym for $slave_editor.
1214 our ($slave_editor);
1215 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1217 =head2 READING THE RC FILE
1219 The debugger will read a file of initialization options if supplied. If
1220 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1224 # As noted, this test really doesn't check accurately that the debugger
1225 # is running at a terminal or not.
1227 use vars qw($rcfile);
1229 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1230 # this is the wrong metric!
1231 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
1236 The debugger does a safety test of the file to be read. It must be owned
1237 either by the current user or root, and must only be writable by the owner.
1241 # This wraps a safety test around "do" to read and evaluate the init file.
1243 # This isn't really safe, because there's a race
1244 # between checking and opening. The solution is to
1245 # open and fstat the handle, but then you have to read and
1246 # eval the contents. But then the silly thing gets
1247 # your lexical scope, which is unfortunate at best.
1251 # Just exactly what part of the word "CORE::" don't you understand?
1252 local $SIG{__WARN__};
1253 local $SIG{__DIE__};
1255 unless ( is_safe_file($file) ) {
1256 CORE::warn <<EO_GRIPE;
1257 perldb: Must not source insecure rcfile $file.
1258 You or the superuser must be the owner, and it must not
1259 be writable by anyone but its owner.
1262 } ## end unless (is_safe_file($file...
1265 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1266 } ## end sub safe_do
1268 # This is the safety test itself.
1270 # Verifies that owner is either real user or superuser and that no
1271 # one but owner may write to it. This function is of limited use
1272 # when called on a path instead of upon a handle, because there are
1273 # no guarantees that filename (by dirent) whose file (by ino) is
1274 # eventually accessed is the same as the one tested.
1275 # Assumes that the file's existence is not in doubt.
1278 stat($path) || return; # mysteriously vaporized
1279 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1281 return 0 if $uid != 0 && $uid != $<;
1282 return 0 if $mode & 022;
1284 } ## end sub is_safe_file
1286 # If the rcfile (whichever one we decided was the right one to read)
1287 # exists, we safely do it.
1289 safe_do("./$rcfile");
1292 # If there isn't one here, try the user's home directory.
1293 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1294 safe_do("$ENV{HOME}/$rcfile");
1297 # Else try the login directory.
1298 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1299 safe_do("$ENV{LOGDIR}/$rcfile");
1302 # If the PERLDB_OPTS variable has options in it, parse those out next.
1303 if ( defined $ENV{PERLDB_OPTS} ) {
1304 parse_options( $ENV{PERLDB_OPTS} );
1309 The last thing we do during initialization is determine which subroutine is
1310 to be used to obtain a new terminal when a new debugger is started. Right now,
1311 the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
1316 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1317 # Works if you're running an xterm or xterm-like window, or you're on
1318 # OS/2, or on Mac OS X. This may need some expansion.
1320 if (not defined &get_fork_TTY) # only if no routine exists
1322 if ( defined $remoteport ) {
1323 # Expect an inetd-like server
1324 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1326 elsif (defined $ENV{TERM} # If we know what kind
1327 # of terminal this is,
1328 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1329 and defined $ENV{DISPLAY} # and what display it's on,
1332 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1334 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1335 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1337 elsif ( $^O eq 'darwin' # If this is Mac OS X
1338 and defined $ENV{TERM_PROGRAM} # and we're running inside
1339 and $ENV{TERM_PROGRAM}
1340 eq 'Apple_Terminal' # Terminal.app
1343 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1345 } ## end if (not defined &get_fork_TTY...
1347 # untaint $^O, which may have been tainted by the last statement.
1348 # see bug [perl #24674]
1352 # Here begin the unreadable code. It needs fixing.
1354 =head2 RESTART PROCESSING
1356 This section handles the restart command. When the C<R> command is invoked, it
1357 tries to capture all of the state it can into environment variables, and
1358 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1359 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1360 the R command stuffed into the environment variables.
1362 PERLDB_RESTART - flag only, contains no restart data itself.
1363 PERLDB_HIST - command history, if it's available
1364 PERLDB_ON_LOAD - breakpoints set by the rc file
1365 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1366 PERLDB_VISITED - files that had breakpoints
1367 PERLDB_FILE_... - breakpoints for a file
1368 PERLDB_OPT - active options
1369 PERLDB_INC - the original @INC
1370 PERLDB_PRETYPE - preprompt debugger actions
1371 PERLDB_PRE - preprompt Perl code
1372 PERLDB_POST - post-prompt Perl code
1373 PERLDB_TYPEAHEAD - typeahead captured by readline()
1375 We chug through all these variables and plug the values saved in them
1376 back into the appropriate spots in the debugger.
1380 use vars qw(%postponed_file @typeahead);
1382 our (@hist, @truehist);
1384 sub _restore_shared_globals_after_restart
1386 @hist = get_list('PERLDB_HIST');
1387 %break_on_load = get_list("PERLDB_ON_LOAD");
1388 %postponed = get_list("PERLDB_POSTPONE");
1392 share(%break_on_load);
1396 sub _restore_breakpoints_and_actions {
1398 my @had_breakpoints = get_list("PERLDB_VISITED");
1400 for my $file_idx ( 0 .. $#had_breakpoints ) {
1401 my $filename = $had_breakpoints[$file_idx];
1402 my %pf = get_list("PERLDB_FILE_$file_idx");
1403 $postponed_file{ $filename } = \%pf if %pf;
1404 my @lines = sort {$a <=> $b} keys(%pf);
1405 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1406 for my $line_idx (0 .. $#lines) {
1407 _set_breakpoint_enabled_status(
1410 ($enabled_statuses[$line_idx] ? 1 : ''),
1418 sub _restore_options_after_restart
1420 my %options_map = get_list("PERLDB_OPT");
1422 while ( my ( $opt, $val ) = each %options_map ) {
1423 $val =~ s/[\\\']/\\$1/g;
1424 parse_options("$opt'$val'");
1430 sub _restore_globals_after_restart
1432 # restore original @INC
1433 @INC = get_list("PERLDB_INC");
1436 # return pre/postprompt actions and typeahead buffer
1437 $pretype = [ get_list("PERLDB_PRETYPE") ];
1438 $pre = [ get_list("PERLDB_PRE") ];
1439 $post = [ get_list("PERLDB_POST") ];
1440 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1446 if ( exists $ENV{PERLDB_RESTART} ) {
1448 # We're restarting, so we don't need the flag that says to restart anymore.
1449 delete $ENV{PERLDB_RESTART};
1452 _restore_shared_globals_after_restart();
1454 _restore_breakpoints_and_actions();
1457 _restore_options_after_restart();
1459 _restore_globals_after_restart();
1460 } ## end if (exists $ENV{PERLDB_RESTART...
1462 =head2 SETTING UP THE TERMINAL
1464 Now, we'll decide how the debugger is going to interact with the user.
1465 If there's no TTY, we set the debugger to run non-stop; there's not going
1466 to be anyone there to enter commands.
1470 use vars qw($notty $console $tty $LINEINFO);
1471 use vars qw($lineinfo $doccmd);
1482 If there is a TTY, we have to determine who it belongs to before we can
1483 proceed. If this is a slave editor or graphical debugger (denoted by
1484 the first command-line switch being '-emacs'), we shift this off and
1485 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1491 # Is Perl being run from a slave editor or graphical debugger?
1492 # If so, don't use readline, and set $slave_editor = 1.
1493 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1498 #require Term::ReadLine;
1502 We then determine what the console should be on various systems:
1506 =item * Cygwin - We use C<stdin> instead of a separate device.
1510 if ( $^O eq 'cygwin' ) {
1512 # /dev/tty is binary. use stdin for textmode
1516 =item * Unix - use C</dev/tty>.
1520 elsif ( -e "/dev/tty" ) {
1521 $console = "/dev/tty";
1524 =item * Windows or MSDOS - use C<con>.
1528 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1532 =item * VMS - use C<sys$command>.
1538 # everything else is ...
1539 $console = "sys\$command";
1546 Several other systems don't use a specific console. We C<undef $console>
1547 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1548 with a slave editor, Epoc).
1552 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1554 # /dev/tty is binary. use stdin for textmode
1558 if ( $^O eq 'NetWare' ) {
1560 # /dev/tty is binary. use stdin for textmode
1564 # In OS/2, we need to use STDIN to get textmode too, even though
1565 # it pretty much looks like Unix otherwise.
1566 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1571 # EPOC also falls into the 'got to use STDIN' camp.
1572 if ( $^O eq 'epoc' ) {
1578 If there is a TTY hanging around from a parent, we use that as the console.
1582 $console = $tty if defined $tty;
1584 =head2 SOCKET HANDLING
1586 The debugger is capable of opening a socket and carrying out a debugging
1587 session over the socket.
1589 If C<RemotePort> was defined in the options, the debugger assumes that it
1590 should try to start a debugging session on that port. It builds the socket
1591 and then tries to connect the input and output filehandles to it.
1595 # Handle socket stuff.
1597 if ( defined $remoteport ) {
1599 # If RemotePort was defined in the options, connect input and output
1601 $IN = $OUT = connect_remoteport();
1602 } ## end if (defined $remoteport)
1606 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1607 this is probably a situation where multiple debuggers are running (for example,
1608 a backticked command that starts up another debugger). We create a new IN and
1609 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1617 # Two debuggers running (probably a system or a backtick that invokes
1618 # the debugger itself under the running one). create a new IN and OUT
1619 # filehandle, and do the necessary mojo to create a new tty if we
1620 # know how, and we can.
1621 create_IN_OUT(4) if $CreateTTY & 4;
1624 # If we have a console, check to see if there are separate ins and
1625 # outs to open. (They are assumed identical if not.)
1627 my ( $i, $o ) = split /,/, $console;
1628 $o = $i unless defined $o;
1630 # read/write on in, or just read, or read on STDIN.
1632 || open( IN, "<$i" )
1633 || open( IN, "<&STDIN" );
1635 # read/write/create/clobber out, or write/create/clobber out,
1636 # or merge with STDERR, or merge with STDOUT.
1638 || open( OUT, ">$o" )
1639 || open( OUT, ">&STDERR" )
1640 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1642 } ## end if ($console)
1643 elsif ( not defined $console ) {
1645 # No console. Open STDIN.
1646 open( IN, "<&STDIN" );
1648 # merge with STDERR, or with STDOUT.
1649 open( OUT, ">&STDERR" )
1650 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1651 $console = 'STDIN/OUT';
1652 } ## end elsif (not defined $console)
1654 # Keep copies of the filehandles so that when the pager runs, it
1655 # can close standard input without clobbering ours.
1656 if ($console or (not defined($console))) {
1660 } ## end elsif (from if(defined $remoteport))
1662 # Unbuffer DB::OUT. We need to see responses right away.
1665 # Line info goes to debugger output unless pointed elsewhere.
1666 # Pointing elsewhere makes it possible for slave editors to
1667 # keep track of file and position. We have both a filehandle
1668 # and a I/O description to keep track of.
1669 $LINEINFO = $OUT unless defined $LINEINFO;
1670 $lineinfo = $console unless defined $lineinfo;
1671 # share($LINEINFO); # <- unable to share globs
1676 To finish initialization, we show the debugger greeting,
1677 and then call the C<afterinit()> subroutine if there is one.
1681 # Show the debugger greeting.
1682 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1683 unless ($runnonstop) {
1686 if ( $term_pid eq '-1' ) {
1687 print $OUT "\nDaughter DB session started...\n";
1690 print $OUT "\nLoading DB routines from $header\n";
1693 $slave_editor ? "enabled" : "available", ".\n"
1696 "\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
1697 } ## end else [ if ($term_pid eq '-1')
1698 } ## end unless ($runnonstop)
1699 } ## end else [ if ($notty)
1701 # XXX This looks like a bug to me.
1702 # Why copy to @ARGS and then futz with @args?
1705 # Make sure backslashes before single quotes are stripped out, and
1706 # keep args unless they are numeric (XXX why?)
1707 # s/\'/\\\'/g; # removed while not justified understandably
1708 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1711 # If there was an afterinit() sub defined, call it. It will get
1712 # executed in our scope, so it can fiddle with debugger globals.
1713 if ( defined &afterinit ) { # May be defined in $rcfile
1717 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1718 use vars qw($I_m_init);
1722 ############################################################ Subroutines
1728 This gigantic subroutine is the heart of the debugger. Called before every
1729 statement, its job is to determine if a breakpoint has been reached, and
1730 stop if so; read commands from the user, parse them, and execute
1731 them, and then send execution off to the next statement.
1733 Note that the order in which the commands are processed is very important;
1734 some commands earlier in the loop will actually alter the C<$cmd> variable
1735 to create other commands to be executed later. This is all highly I<optimized>
1736 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1737 see what's happening in any given command.
1741 # $cmd cannot be an our() variable unfortunately (possible perl bug?).
1771 sub _DB__determine_if_we_should_break
1773 # if we have something here, see if we should break.
1774 # $stop is lexical and local to this block - $action on the other hand
1779 && _is_breakpoint_enabled($filename, $line)
1780 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1783 # Stop if the stop criterion says to just stop.
1784 if ( $stop eq '1' ) {
1788 # It's a conditional stop; eval it in the user's context and
1789 # see if we should stop. If so, remove the one-time sigil.
1791 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1793 # If the breakpoint is temporary, then delete its enabled status.
1794 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1795 _cancel_breakpoint_temp_enabled_status($filename, $line);
1798 } ## end if ($dbline{$line} && ...
1801 sub _DB__is_finished {
1802 if ($finished and $level <= 1) {
1811 sub _DB__read_next_cmd
1815 # We have a terminal, or can get one ...
1820 # ... and it belogs to this PID or we get one for this PID ...
1821 if ($term_pid != $$) {
1825 # ... and we got a line of command input ...
1826 $cmd = DB::readline(
1827 "$pidprompt $tid DB"
1830 . ( '>' x $level ) . " "
1833 return defined($cmd);
1836 sub _DB__trim_command_and_return_first_component {
1839 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1840 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1842 my ($verb, $args) = $cmd =~ m{\A(\S*)\s*(.*)}s;
1844 $obj->cmd_verb($verb);
1845 $obj->cmd_args($args);
1850 sub _DB__handle_f_command {
1853 if ($file = $obj->cmd_args) {
1854 # help for no arguments (old-style was return from sub).
1857 "The old f command is now the r command.\n"; # hint
1858 print $OUT "The new f command switches filenames.\n";
1860 } ## end if (!$file)
1862 # if not in magic file list, try a close match.
1863 if ( !defined $main::{ '_<' . $file } ) {
1864 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1866 $try = substr( $try, 2 );
1867 print $OUT "Choosing $try matching '$file':\n";
1870 } ## end if (($try) = grep(m#^_<.*$file#...
1871 } ## end if (!defined $main::{ ...
1873 # If not successfully switched now, we failed.
1874 if ( !defined $main::{ '_<' . $file } ) {
1875 print $OUT "No file matching '$file' is loaded.\n";
1879 # We switched, so switch the debugger internals around.
1880 elsif ( $file ne $filename ) {
1881 *dbline = $main::{ '_<' . $file };
1886 } ## end elsif ($file ne $filename)
1888 # We didn't switch; say we didn't.
1890 print $OUT "Already in $file.\n";
1898 sub _DB__handle_dot_command {
1902 if ($obj->_is_full('.')) {
1903 $incr = -1; # stay at current line
1905 # Reset everything to the old location.
1907 $filename = $filename_ini;
1908 *dbline = $main::{ '_<' . $filename };
1912 print_lineinfo($obj->position());
1919 sub _DB__handle_y_command {
1922 if (my ($match_level, $match_vars)
1923 = $obj->cmd_args =~ /\A(?:(\d*)\s*(.*))?\z/) {
1925 # See if we've got the necessary support.
1926 if (!eval { require PadWalker; PadWalker->VERSION(0.08) }) {
1930 ? "PadWalker module not found - please install\n"
1936 # Load up dumpvar if we don't have it. If we can, that is.
1937 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1938 defined &main::dumpvar
1939 or print $OUT "dumpvar.pl not available.\n"
1942 # Got all the modules we need. Find them and print them.
1943 my @vars = split( ' ', $match_vars || '' );
1946 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
1948 # Oops. Can't find it.
1955 # Show the desired vars with dumplex().
1956 my $savout = select($OUT);
1958 # Have dumplex dump the lexicals.
1959 foreach my $key (sort keys %$h) {
1960 dumpvar::dumplex( $key, $h->{$key},
1961 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
1969 sub _DB__handle_c_command {
1972 my $i = $obj->cmd_args;
1974 if ($i =~ m#\A[\w:]*\z#) {
1976 # Hey, show's over. The debugged program finished
1977 # executing already.
1978 next CMD if _DB__is_finished();
1980 # Capture the place to put a one-time break.
1983 # Probably not needed, since we finish an interactive
1984 # sub-session anyway...
1985 # local $filename = $filename;
1986 # local *dbline = *dbline; # XXX Would this work?!
1988 # The above question wonders if localizing the alias
1989 # to the magic array works or not. Since it's commented
1990 # out, we'll just leave that to speculation for now.
1992 # If the "subname" isn't all digits, we'll assume it
1993 # is a subroutine name, and try to find it.
1994 if ( $subname =~ /\D/ ) { # subroutine name
1995 # Qualify it to the current package unless it's
1996 # already qualified.
1997 $subname = $package . "::" . $subname
1998 unless $subname =~ /::/;
2000 # find_sub will return "file:line_number" corresponding
2001 # to where the subroutine is defined; we call find_sub,
2002 # break up the return value, and assign it in one
2004 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2006 # Force the line number to be numeric.
2009 # If we got a line number, we found the sub.
2012 # Switch all the debugger's internals around so
2013 # we're actually working with that file.
2015 *dbline = $main::{ '_<' . $filename };
2017 # Mark that there's a breakpoint in this file.
2018 $had_breakpoints{$filename} |= 1;
2020 # Scan forward to the first executable line
2021 # after the 'sub whatever' line.
2024 while ($dbline[$_line_num] == 0 && $_line_num< $max)
2031 # We didn't find a sub by that name.
2033 print $OUT "Subroutine $subname not found.\n";
2036 } ## end if ($subname =~ /\D/)
2038 # At this point, either the subname was all digits (an
2039 # absolute line-break request) or we've scanned through
2040 # the code following the definition of the sub, looking
2041 # for an executable, which we may or may not have found.
2043 # If $i (which we set $subname from) is non-zero, we
2044 # got a request to break at some line somewhere. On
2045 # one hand, if there wasn't any real subroutine name
2046 # involved, this will be a request to break in the current
2047 # file at the specified line, so we have to check to make
2048 # sure that the line specified really is breakable.
2050 # On the other hand, if there was a subname supplied, the
2051 # preceding block has moved us to the proper file and
2052 # location within that file, and then scanned forward
2053 # looking for the next executable line. We have to make
2054 # sure that one was found.
2056 # On the gripping hand, we can't do anything unless the
2057 # current value of $i points to a valid breakable line.
2062 if ( $dbline[$i] == 0 ) {
2063 print $OUT "Line $i not breakable.\n";
2067 # Yes. Set up the one-time-break sigil.
2068 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2069 _enable_breakpoint_temp_enabled_status($filename, $i);
2072 # Turn off stack tracing from here up.
2073 for my $j (0 .. $stack_depth) {
2082 sub _DB__handle_forward_slash_command {
2085 # The pattern as a string.
2086 use vars qw($inpat);
2088 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2090 # Remove the final slash.
2091 $inpat =~ s:([^\\])/$:$1:;
2093 # If the pattern isn't null ...
2094 if ( $inpat ne "" ) {
2096 # Turn of warn and die procesing for a bit.
2097 local $SIG{__DIE__};
2098 local $SIG{__WARN__};
2100 # Create the pattern.
2101 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2104 # Oops. Bad pattern. No biscuit.
2105 # Print the eval error and go back for more
2111 } ## end if ($inpat ne "")
2113 # Set up to stop on wrap-around.
2116 # Don't move off the current line.
2119 my $pat = $obj->pat;
2121 # Done in eval so nothing breaks if the pattern
2122 # does something weird.
2127 # Move ahead one line.
2130 # Wrap if we pass the last line.
2131 $start = 1 if ($start > $max);
2133 # Stop if we have gotten back to this line again,
2134 last if ($start == $end);
2136 # A hit! (Note, though, that we are doing
2137 # case-insensitive matching. Maybe a qr//
2138 # expression would be better, so the user could
2139 # do case-sensitive matching if desired.
2140 if ($dbline[$start] =~ m/$pat/i) {
2141 if ($slave_editor) {
2142 # Handle proper escaping in the slave.
2143 print $OUT "\032\032$filename:$start:0\n";
2146 # Just print the line normally.
2147 print $OUT "$start:\t",$dbline[$start],"\n";
2149 # And quit since we found something.
2159 # If we wrapped, there never was a match.
2160 if ( $start == $end ) {
2161 print {$OUT} "/$pat/: not found\n";
2169 sub _DB__handle_question_mark_command {
2172 # ? - backward pattern search.
2173 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2175 # Get the pattern, remove trailing question mark.
2176 $inpat =~ s:([^\\])\?$:$1:;
2178 # If we've got one ...
2179 if ( $inpat ne "" ) {
2181 # Turn off die & warn handlers.
2182 local $SIG{__DIE__};
2183 local $SIG{__WARN__};
2184 eval '$inpat =~ m' . "\a$inpat\a";
2188 # Ouch. Not good. Print the error.
2193 } ## end if ($inpat ne "")
2195 # Where we are now is where to stop after wraparound.
2198 # Don't move away from this line.
2201 my $pat = $obj->pat;
2202 # Search inside the eval to prevent pattern badness
2210 # Wrap if we pass the first line.
2212 $start = $max if ($start <= 0);
2214 # Quit if we get back where we started,
2215 last if ($start == $end);
2218 if ($dbline[$start] =~ m/$pat/i) {
2219 if ($slave_editor) {
2220 # Yep, follow slave editor requirements.
2221 print $OUT "\032\032$filename:$start:0\n";
2224 # Yep, just print normally.
2225 print $OUT "$start:\t",$dbline[$start],"\n";
2234 # Say we failed if the loop never found anything,
2235 if ( $start == $end ) {
2236 print {$OUT} "?$pat?: not found\n";
2244 sub _DB__handle_restart_and_rerun_commands {
2247 my $cmd_cmd = $obj->cmd_verb;
2248 my $cmd_params = $obj->cmd_args;
2249 # R - restart execution.
2250 # rerun - controlled restart execution.
2251 if ($cmd_cmd eq 'rerun' or $cmd_params eq '') {
2252 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
2254 # Close all non-system fds for a clean restart. A more
2255 # correct method would be to close all fds that were not
2256 # open when the process started, but this seems to be
2257 # hard. See "debugger 'R'estart and open database
2258 # connections" on p5p.
2260 my $max_fd = 1024; # default if POSIX can't be loaded
2261 if (eval { require POSIX }) {
2262 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
2265 if (defined $max_fd) {
2266 foreach ($^F+1 .. $max_fd-1) {
2267 next unless open FD_TO_CLOSE, "<&=$_";
2272 # And run Perl again. We use exec() to keep the
2273 # PID stable (and that way $ini_pids is still valid).
2274 exec(@args) or print {$OUT} "exec failed: $!\n";
2282 sub _DB__handle_run_command_in_pager_command {
2285 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
2286 if ( $pager =~ /^\|/ ) {
2288 # Default pager is into a pipe. Redirect I/O.
2289 open( SAVEOUT, ">&STDOUT" )
2290 || _db_warn("Can't save STDOUT");
2291 open( STDOUT, ">&OUT" )
2292 || _db_warn("Can't redirect STDOUT");
2293 } ## end if ($pager =~ /^\|/)
2296 # Not into a pipe. STDOUT is safe.
2297 open( SAVEOUT, ">&OUT" ) || _db_warn("Can't save DB::OUT");
2300 # Fix up environment to record we have less if so.
2303 unless ( $obj->piped(scalar ( open( OUT, $pager ) ) ) ) {
2305 # Couldn't open pipe to pager.
2306 _db_warn("Can't pipe output to '$pager'");
2307 if ( $pager =~ /^\|/ ) {
2309 # Redirect I/O back again.
2310 open( OUT, ">&STDOUT" ) # XXX: lost message
2311 || _db_warn("Can't restore DB::OUT");
2312 open( STDOUT, ">&SAVEOUT" )
2313 || _db_warn("Can't restore STDOUT");
2315 } ## end if ($pager =~ /^\|/)
2318 # Redirect I/O. STDOUT already safe.
2319 open( OUT, ">&STDOUT" ) # XXX: lost message
2320 || _db_warn("Can't restore DB::OUT");
2323 } ## end unless ($piped = open(OUT,...
2325 # Set up broken-pipe handler if necessary.
2326 $SIG{PIPE} = \&DB::catch
2328 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
2331 # Save current filehandle, and put it back.
2332 $obj->selected(scalar( select(OUT) ));
2333 # Don't put it back if pager was a pipe.
2334 if ($cmd !~ /\A\|\|/)
2336 select($obj->selected());
2340 # Trim off the pipe symbols and run the command now.
2341 $cmd =~ s#\A\|+\s*##;
2348 sub _DB__handle_m_command {
2351 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2356 # m expr - set up DB::eval to do the work
2357 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2358 $onetimeDump = 'methods'; # method output gets used there
2364 sub _DB__at_end_of_every_command {
2367 # At the end of every command:
2370 # Unhook the pipe mechanism now.
2371 if ( $pager =~ /^\|/ ) {
2373 # No error from the child.
2376 # we cannot warn here: the handle is missing --tchrist
2377 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
2379 # most of the $? crud was coping with broken cshisms
2380 # $? is explicitly set to 0, so this never runs.
2382 print SAVEOUT "Pager '$pager' failed: ";
2384 print SAVEOUT "shell returned -1\n";
2387 print SAVEOUT ( $? & 127 )
2388 ? " (SIG#" . ( $? & 127 ) . ")"
2389 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
2392 print SAVEOUT "status ", ( $? >> 8 ), "\n";
2396 # Reopen filehandle for our output (if we can) and
2397 # restore STDOUT (if we can).
2398 open( OUT, ">&STDOUT" ) || _db_warn("Can't restore DB::OUT");
2399 open( STDOUT, ">&SAVEOUT" )
2400 || _db_warn("Can't restore STDOUT");
2402 # Turn off pipe exception handler if necessary.
2403 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
2405 # Will stop ignoring SIGPIPE if done like nohup(1)
2406 # does SIGINT but Perl doesn't give us a choice.
2407 } ## end if ($pager =~ /^\|/)
2410 # Non-piped "pager". Just restore STDOUT.
2411 open( OUT, ">&SAVEOUT" ) || _db_warn("Can't restore DB::OUT");
2414 # Close filehandle pager was using, restore the normal one
2418 if ($obj->selected() ne "") {
2419 select($obj->selected);
2425 } ## end if ($piped)
2432 # 'v' is the value (i.e: method name or subroutine ref).
2433 # 's' is subroutine.
2436 '-' => { t => 'm', v => '_handle_dash_command', },
2437 '.' => { t => 's', v => \&_DB__handle_dot_command, },
2438 '=' => { t => 'm', v => '_handle_equal_sign_command', },
2439 'H' => { t => 'm', v => '_handle_H_command', },
2440 'S' => { t => 'm', v => '_handle_S_command', },
2441 'T' => { t => 'm', v => '_handle_T_command', },
2442 'W' => { t => 'm', v => '_handle_W_command', },
2443 'c' => { t => 's', v => \&_DB__handle_c_command, },
2444 'f' => { t => 's', v => \&_DB__handle_f_command, },
2445 'm' => { t => 's', v => \&_DB__handle_m_command, },
2446 'n' => { t => 'm', v => '_handle_n_command', },
2447 'p' => { t => 'm', v => '_handle_p_command', },
2448 'q' => { t => 'm', v => '_handle_q_command', },
2449 'r' => { t => 'm', v => '_handle_r_command', },
2450 's' => { t => 'm', v => '_handle_s_command', },
2451 'save' => { t => 'm', v => '_handle_save_command', },
2452 'source' => { t => 'm', v => '_handle_source_command', },
2453 't' => { t => 'm', v => '_handle_t_command', },
2454 'w' => { t => 'm', v => '_handle_w_command', },
2455 'x' => { t => 'm', v => '_handle_x_command', },
2456 'y' => { t => 's', v => \&_DB__handle_y_command, },
2457 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, }
2459 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, }
2460 qw(enable disable)),
2462 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, },
2464 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, }
2465 qw(a A b B e E h i l L M o O P v w W)),
2470 # lock the debugger and get the thread id for the prompt
2474 my ($prefix, $after, $infix);
2480 if ($ENV{PERL5DB_THREADED}) {
2481 $tid = eval { "[".threads->tid."]" };
2487 my $obj = DB::Obj->new(
2489 position => \$position,
2492 explicit_stop => \$explicit_stop,
2494 cmd_args => \$cmd_args,
2495 cmd_verb => \$cmd_verb,
2498 selected => \$selected,
2502 $obj->_DB_on_init__initialize_globals(@_);
2504 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2505 # The code being debugged may have altered them.
2508 # Since DB::DB gets called after every line, we can use caller() to
2509 # figure out where we last were executing. Sneaky, eh? This works because
2510 # caller is returning all the extra information when called from the
2512 local ( $package, $filename, $line ) = caller;
2513 $filename_ini = $filename;
2515 # set up the context for DB::eval, so it can properly execute
2516 # code on behalf of the user. We add the package in so that the
2517 # code is eval'ed in the proper package (not in the debugger!).
2518 local $usercontext = _calc_usercontext($package);
2520 # Create an alias to the active file magical array to simplify
2522 local (*dbline) = $main::{ '_<' . $filename };
2524 # Last line in the program.
2527 _DB__determine_if_we_should_break(@_);
2529 # Preserve the current stop-or-not, and see if any of the W
2530 # (watch expressions) has changed.
2531 my $was_signal = $signal;
2533 # If we have any watch expressions ...
2534 $obj->_DB__handle_watch_expressions(@_);
2536 =head2 C<watchfunction()>
2538 C<watchfunction()> is a function that can be defined by the user; it is a
2539 function which will be run on each entry to C<DB::DB>; it gets the
2540 current package, filename, and line as its parameters.
2542 The watchfunction can do anything it likes; it is executing in the
2543 debugger's context, so it has access to all of the debugger's internal
2544 data structures and functions.
2546 C<watchfunction()> can control the debugger's actions. Any of the following
2547 will cause the debugger to return control to the user's program after
2548 C<watchfunction()> executes:
2554 Returning a false value from the C<watchfunction()> itself.
2558 Altering C<$single> to a false value.
2562 Altering C<$signal> to a false value.
2566 Turning off the C<4> bit in C<$trace> (this also disables the
2567 check for C<watchfunction()>. This can be done with
2575 # If there's a user-defined DB::watchfunction, call it with the
2576 # current package, filename, and line. The function executes in
2578 if ( $trace & 4 ) { # User-installed watch
2580 if watchfunction( $package, $filename, $line )
2583 and not( $trace & ~4 );
2584 } ## end if ($trace & 4)
2586 # Pick up any alteration to $signal in the watchfunction, and
2587 # turn off the signal now.
2588 $was_signal = $signal;
2591 =head2 GETTING READY TO EXECUTE COMMANDS
2593 The debugger decides to take control if single-step mode is on, the
2594 C<t> command was entered, or the user generated a signal. If the program
2595 has fallen off the end, we set things up so that entering further commands
2596 won't cause trouble, and we say that the program is over.
2600 # Make sure that we always print if asked for explicitly regardless
2601 # of $trace_to_depth .
2602 $explicit_stop = ($single || $was_signal);
2604 # Check to see if we should grab control ($single true,
2605 # trace set appropriately, or we got a signal).
2606 if ( $explicit_stop || ( $trace & 1 ) ) {
2607 $obj->_DB__grab_control(@_);
2608 } ## end if ($single || ($trace...
2612 If there's an action to be executed for the line we stopped at, execute it.
2613 If there are any preprompt actions, execute those as well.
2617 # If there's an action, do it now.
2623 # Are we nested another level (e.g., did we evaluate a function
2624 # that had a breakpoint in it at the debugger prompt)?
2625 if ( $single || $was_signal ) {
2627 # Yes, go down a level.
2628 local $level = $level + 1;
2630 # Do any pre-prompt actions.
2631 foreach $evalarg (@$pre) {
2635 # Complain about too much recursion if we passed the limit.
2637 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2640 # The line we're currently on. Set $incr to -1 to stay here
2641 # until we get a command that tells us to advance.
2643 $incr = -1; # for backward motion.
2645 # Tack preprompt debugger actions ahead of any actual input.
2646 @typeahead = ( @$pretype, @typeahead );
2648 =head2 WHERE ARE WE?
2650 XXX Relocate this section?
2652 The debugger normally shows the line corresponding to the current line of
2653 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2654 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2656 C<$incr> controls by how many lines the I<current> line should move forward
2657 after a command is executed. If set to -1, this indicates that the I<current>
2658 line shouldn't change.
2660 C<$start> is the I<current> line. It is used for things like knowing where to
2661 move forwards or backwards from when doing an C<L> or C<-> command.
2663 C<$max> tells the debugger where the last line of the current file is. It's
2664 used to terminate loops most often.
2666 =head2 THE COMMAND LOOP
2668 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2675 The outer part of the loop, starting at the C<CMD> label. This loop
2676 reads a command and then executes it.
2680 The inner part of the loop, starting at the C<PIPE> label. This part
2681 is wholly contained inside the C<CMD> block and only executes a command.
2682 Used to handle commands running inside a pager.
2686 So why have two labels to restart the loop? Because sometimes, it's easier to
2687 have a command I<generate> another command and then re-execute the loop to do
2688 the new command. This is faster, but perhaps a bit more convoluted.
2692 # The big command dispatch loop. It keeps running until the
2693 # user yields up control again.
2695 # If we have a terminal for input, and we get something back
2696 # from readline(), keep on processing.
2699 while (_DB__read_next_cmd($tid))
2703 # ... try to execute the input as debugger commands.
2705 # Don't stop running.
2708 # No signal is active.
2711 # Handle continued commands (ending with \):
2712 if ($cmd =~ s/\\\z/\n/) {
2713 $cmd .= DB::readline(" cont: ");
2717 =head4 The null command
2719 A newline entered by itself means I<re-execute the last command>. We grab the
2720 command out of C<$laststep> (where it was recorded previously), and copy it
2721 back into C<$cmd> to be executed below. If there wasn't any previous command,
2722 we'll do nothing below (no command will match). If there was, we also save it
2723 in the command history and fall through to allow the command parsing to pick
2728 # Empty input means repeat the last command.
2732 chomp($cmd); # get rid of the annoying extra newline
2733 if (length($cmd) >= 2) {
2734 push( @hist, $cmd );
2736 push( @truehist, $cmd );
2740 # This is a restart point for commands that didn't arrive
2741 # via direct user input. It allows us to 'redo PIPE' to
2742 # re-execute command processing without reading a new command.
2744 _DB__trim_command_and_return_first_component($obj);
2746 =head3 COMMAND ALIASES
2748 The debugger can create aliases for commands (these are stored in the
2749 C<%alias> hash). Before a command is executed, the command loop looks it up
2750 in the alias hash and substitutes the contents of the alias for the command,
2751 completely replacing it.
2755 # See if there's an alias for the command, and set it up if so.
2756 if ( $alias{$cmd_verb} ) {
2758 # Squelch signal handling; we want to keep control here
2759 # if something goes loco during the alias eval.
2760 local $SIG{__DIE__};
2761 local $SIG{__WARN__};
2763 # This is a command, so we eval it in the DEBUGGER's
2764 # scope! Otherwise, we can't see the special debugger
2765 # variables, or get to the debugger's subs. (Well, we
2766 # _could_, but why make it even more complicated?)
2767 eval "\$cmd =~ $alias{$cmd_verb}";
2770 print $OUT "Couldn't evaluate '$cmd_verb' alias: $@";
2773 _DB__trim_command_and_return_first_component($obj);
2774 } ## end if ($alias{$cmd_verb})
2776 =head3 MAIN-LINE COMMANDS
2778 All of these commands work up to and after the program being debugged has
2783 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2784 try to execute further, cleaning any restart-related stuff out of the
2785 environment, and executing with the last value of C<$?>.
2789 # All of these commands were remapped in perl 5.8.0;
2790 # we send them off to the secondary dispatcher (see below).
2791 $obj->_handle_special_char_cmd_wrapper_commands;
2792 _DB__trim_command_and_return_first_component($obj);
2794 if (my $cmd_rec = $cmd_lookup{$cmd_verb}) {
2795 my $type = $cmd_rec->{t};
2796 my $val = $cmd_rec->{v};
2800 elsif ($type eq 's') {
2805 =head4 C<t> - trace [n]
2807 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2808 If level is specified, set C<$trace_to_depth>.
2810 =head4 C<S> - list subroutines matching/not matching a pattern
2812 Walks through C<%sub>, checking to see whether or not to print the name.
2814 =head4 C<X> - list variables in current package
2816 Since the C<V> command actually processes this, just change this to the
2817 appropriate C<V> command and fall through.
2819 =head4 C<V> - list variables
2821 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2823 =head4 C<x> - evaluate and print an expression
2825 Hands the expression off to C<DB::eval>, setting it up to print the value
2826 via C<dumpvar.pl> instead of just printing it directly.
2828 =head4 C<m> - print methods
2830 Just uses C<DB::methods> to determine what methods are available.
2832 =head4 C<f> - switch files
2834 Switch to a different filename.
2836 =head4 C<.> - return to last-executed line.
2838 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2839 and then we look up the line in the magical C<%dbline> hash.
2841 =head4 C<-> - back one window
2843 We change C<$start> to be one window back; if we go back past the first line,
2844 we set it to be the first line. We ser C<$incr> to put us back at the
2845 currently-executing line, and then put a C<l $start +> (list one window from
2846 C<$start>) in C<$cmd> to be executed later.
2848 =head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
2850 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2851 problems, most notably that the default case of several commands destroying
2852 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2853 retain the old commands for those who were used to using them or who preferred
2854 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2855 deal with them instead of processing them in-line.
2857 =head4 C<y> - List lexicals in higher scope
2859 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2860 above the current one and then displays then using C<dumpvar.pl>.
2862 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2864 All of the commands below this point don't work after the program being
2865 debugged has ended. All of them check to see if the program has ended; this
2866 allows the commands to be relocated without worrying about a 'line of
2867 demarcation' above which commands can be entered anytime, and below which
2870 =head4 C<n> - single step, but don't trace down into subs
2872 Done by setting C<$single> to 2, which forces subs to execute straight through
2873 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2874 so a null command knows what to re-execute.
2876 =head4 C<s> - single-step, entering subs
2878 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2879 subs. Also saves C<s> as C<$lastcmd>.
2881 =head4 C<c> - run continuously, setting an optional breakpoint
2883 Most of the code for this command is taken up with locating the optional
2884 breakpoint, which is either a subroutine name or a line number. We set
2885 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2886 in this and all call levels above this one.
2888 =head4 C<r> - return from a subroutine
2890 For C<r> to work properly, the debugger has to stop execution again
2891 immediately after the return is executed. This is done by forcing
2892 single-stepping to be on in the call level above the current one. If
2893 we are printing return values when a C<r> is executed, set C<$doret>
2894 appropriately, and force us out of the command loop.
2896 =head4 C<T> - stack trace
2898 Just calls C<DB::print_trace>.
2900 =head4 C<w> - List window around current line.
2902 Just calls C<DB::cmd_w>.
2904 =head4 C<W> - watch-expression processing.
2906 Just calls C<DB::cmd_W>.
2908 =head4 C</> - search forward for a string in the source
2910 We take the argument and treat it as a pattern. If it turns out to be a
2911 bad one, we return the error we got from trying to C<eval> it and exit.
2912 If not, we create some code to do the search and C<eval> it so it can't
2917 _DB__handle_forward_slash_command($obj);
2919 =head4 C<?> - search backward for a string in the source
2921 Same as for C</>, except the loop runs backwards.
2925 _DB__handle_question_mark_command($obj);
2927 =head4 C<$rc> - Recall command
2929 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2930 that the terminal supports history). It find the the command required, puts it
2931 into C<$cmd>, and redoes the loop to execute it.
2935 # $rc - recall command.
2936 $obj->_handle_rc_recall_command;
2938 =head4 C<$sh$sh> - C<system()> command
2940 Calls the C<_db_system()> to handle the command. This keeps the C<STDIN> and
2941 C<STDOUT> from getting messed up.
2945 $obj->_handle_sh_command;
2947 =head4 C<$rc I<pattern> $rc> - Search command history
2949 Another command to manipulate C<@hist>: this one searches it with a pattern.
2950 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
2954 $obj->_handle_rc_search_history_command;
2956 =head4 C<$sh> - Invoke a shell
2958 Uses C<_db_system()> to invoke a shell.
2962 =head4 C<$sh I<command>> - Force execution of a command in a shell
2964 Like the above, but the command is passed to the shell. Again, we use
2965 C<_db_system()> to avoid problems with C<STDIN> and C<STDOUT>.
2967 =head4 C<H> - display commands in history
2969 Prints the contents of C<@hist> (if any).
2971 =head4 C<man, doc, perldoc> - look up documentation
2973 Just calls C<runman()> to print the appropriate document.
2977 $obj->_handle_doc_command;
2981 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
2982 the bottom of the loop.
2984 =head4 C<=> - define command alias
2986 Manipulates C<%alias> to add or list command aliases.
2988 =head4 C<source> - read commands from a file.
2990 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
2993 =head4 C<enable> C<disable> - enable or disable breakpoints
2995 This enables or disables breakpoints.
2997 =head4 C<save> - send current history to a file
2999 Takes the complete history, (not the shrunken version you see with C<H>),
3000 and saves it to the given filename, so it can be replayed using C<source>.
3002 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3004 =head4 C<R> - restart
3006 Restart the debugger session.
3008 =head4 C<rerun> - rerun the current session
3010 Return to any given position in the B<true>-history list
3012 =head4 C<|, ||> - pipe output through the pager.
3014 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3015 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3016 pipe to the pager (restoring the output filehandles if this fails). If this
3017 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3018 set C<$signal>, sending us back into the debugger.
3020 We then trim off the pipe symbols and C<redo> the command loop at the
3021 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3026 # || - run command in the pager, with output to DB::OUT.
3027 _DB__handle_run_command_in_pager_command($obj);
3029 =head3 END OF COMMAND PARSING
3031 Anything left in C<$cmd> at this point is a Perl expression that we want to
3032 evaluate. We'll always evaluate in the user's context, and fully qualify
3033 any variables we might want to address in the C<DB> package.
3039 # Make sure the flag that says "the debugger's running" is
3040 # still on, to make sure we get control again.
3041 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3043 # Run *our* eval that executes in the caller's context.
3046 # Turn off the one-time-dump stuff now.
3048 $onetimeDump = undef;
3049 $onetimedumpDepth = undef;
3051 elsif ( $term_pid == $$ ) {
3052 eval { # May run under miniperl, when not available...
3057 # XXX If this is the master pid, print a newline.
3060 } ## end while (($term || &setterm...
3062 =head3 POST-COMMAND PROCESSING
3064 After each command, we check to see if the command output was piped anywhere.
3065 If so, we go through the necessary code to unhook the pipe and go back to
3066 our standard filehandles for input and output.
3071 _DB__at_end_of_every_command($obj);
3074 =head3 COMMAND LOOP TERMINATION
3076 When commands have finished executing, we come here. If the user closed the
3077 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3078 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3079 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3080 The interpreter will then execute the next line and then return control to us
3085 # No more commands? Quit.
3086 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
3088 # Evaluate post-prompt commands.
3089 foreach $evalarg (@$post) {
3092 } # if ($single || $signal)
3094 # Put the user's globals back where you found them.
3095 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3104 my $self = bless {}, $class;
3112 my ($self, $args) = @_;
3114 %{$self} = (%$self, %$args);
3121 foreach my $slot_name (qw(
3122 after explicit_stop infix pat piped position prefix selected cmd_verb
3125 my $slot = $slot_name;
3130 ${ $self->{$slot} } = shift;
3133 return ${ $self->{$slot} };
3136 *{"append_to_$slot"} = sub {
3140 return $self->$slot($self->$slot . $s);
3145 sub _DB_on_init__initialize_globals
3149 # Check for whether we should be running continuously or not.
3150 # _After_ the perl program is compiled, $single is set to 1:
3151 if ( $single and not $second_time++ ) {
3153 # Options say run non-stop. Run until we get an interrupt.
3154 if ($runnonstop) { # Disable until signal
3155 # If there's any call stack in place, turn off single
3156 # stepping into subs throughout the stack.
3157 for my $i (0 .. $stack_depth) {
3161 # And we are now no longer in single-step mode.
3164 # If we simply returned at this point, we wouldn't get
3165 # the trace info. Fall on through.
3167 } ## end if ($runnonstop)
3169 elsif ($ImmediateStop) {
3171 # We are supposed to stop here; XXX probably a break.
3172 $ImmediateStop = 0; # We've processed it; turn it off
3173 $signal = 1; # Simulate an interrupt to force
3174 # us into the command loop
3176 } ## end if ($single and not $second_time...
3178 # If we're in single-step mode, or an interrupt (real or fake)
3179 # has occurred, turn off non-stop mode.
3180 $runnonstop = 0 if $single or $signal;
3185 sub _DB__handle_watch_expressions
3190 for my $n (0 .. $#to_watch) {
3191 $evalarg = $to_watch[$n];
3192 local $onetimeDump; # Tell DB::eval() to not output results
3194 # Fix context DB::eval() wants to return an array, but
3195 # we need a scalar here.
3196 my ($val) = join( "', '", DB::eval() );
3197 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
3200 if ( $val ne $old_watch[$n] ) {
3202 # Yep! Show the difference, and fake an interrupt.
3205 Watchpoint $n:\t$to_watch[$n] changed:
3206 old value:\t$old_watch[$n]
3209 $old_watch[$n] = $val;
3210 } ## end if ($val ne $old_watch...
3211 } ## end for my $n (0 ..
3212 } ## end if ($trace & 2)
3217 sub _my_print_lineinfo
3219 my ($self, $i, $incr_pos) = @_;
3222 # Print it indented if tracing is on.
3223 DB::print_lineinfo( ' ' x $stack_depth,
3224 "$i:\t$DB::dbline[$i]" . $self->after );
3227 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3232 return $DB::dbline[$line];
3236 my ($self, $letter) = @_;
3238 return ($DB::cmd eq $letter);
3241 sub _DB__grab_control
3245 # Yes, grab control.
3246 if ($slave_editor) {
3248 # Tell the editor to update its position.
3249 $self->position("\032\032${DB::filename}:$line:0\n");
3250 DB::print_lineinfo($self->position());
3255 Special check: if we're in package C<DB::fake>, we've gone through the
3256 C<END> block at least once. We set up everything so that we can continue
3257 to enter commands and have a valid context to be in.
3261 elsif ( $DB::package eq 'DB::fake' ) {
3263 # Fallen off the end already.
3268 DB::print_help(<<EOP);
3269 Debugged program terminated. Use B<q> to quit or B<R> to restart,
3270 use B<o> I<inhibit_exit> to avoid stopping after program termination,
3271 B<h q>, B<h R> or B<h o> to get additional info.
3274 # Set the DB::eval context appropriately.
3275 $DB::package = 'main';
3276 $DB::usercontext = DB::_calc_usercontext($DB::package);
3277 } ## end elsif ($package eq 'DB::fake')
3281 If the program hasn't finished executing, we scan forward to the
3282 next executable line, print that out, build the prompt from the file and line
3283 number information, and print that.
3290 # Still somewhere in the midst of execution. Set up the
3292 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3293 # Perl 5 ones (sorry, we don't print Klingon
3296 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
3297 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
3298 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
3300 # Break up the prompt if it's really long.
3301 if ( length($self->prefix()) > 30 ) {
3302 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
3304 $self->infix(":\t");
3307 $self->infix("):\t");
3309 $self->prefix . $line. $self->infix
3310 . $self->_curr_line . $self->after
3314 # Print current line info, indenting if necessary.
3315 $self->_my_print_lineinfo($line, $self->position);
3318 my $line_i = sub { return $DB::dbline[$i]; };
3320 # Scan forward, stopping at either the end or the next
3322 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
3325 # Drop out on null statements, block closers, and comments.
3326 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
3328 # Drop out if the user interrupted us.
3331 # Append a newline if the line doesn't have one. Can happen
3332 # in eval'ed text, for instance.
3333 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
3335 # Next executable line.
3336 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
3338 $self->append_to_position($incr_pos);
3339 $self->_my_print_lineinfo($i, $incr_pos);
3340 } ## end for ($i = $line + 1 ; $i...
3341 } ## end else [ if ($slave_editor)
3346 sub _handle_t_command {
3349 my $levels = $self->cmd_args();
3351 if ((!length($levels)) or ($levels !~ /\D/)) {
3354 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3355 print {$OUT} "Trace = "
3357 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3366 sub _handle_S_command {
3369 if (my ($print_all_subs, $should_reverse, $Spatt)
3370 = $self->cmd_args =~ /\A((!)?(.+))?\z/) {
3371 # $Spatt is the pattern (if any) to use.
3373 my $Srev = defined $should_reverse;
3374 # No args - print all subs.
3375 my $Snocheck = !defined $print_all_subs;
3377 # Need to make these sane here.
3381 # Search through the debugger's magical hash of subs.
3382 # If $nocheck is true, just print the sub name.
3383 # Otherwise, check it against the pattern. We then use
3384 # the XOR trick to reverse the condition as required.
3385 foreach $subname ( sort( keys %sub ) ) {
3386 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3387 print $OUT $subname, "\n";
3396 sub _handle_V_command_and_X_command {
3399 $DB::cmd =~ s/^X\b/V $DB::package/;
3401 # Bare V commands get the currently-being-debugged package
3403 if ($self->_is_full('V')) {
3404 $DB::cmd = "V $DB::package";
3407 # V - show variables in package.
3408 if (my ($new_packname, $new_vars_str) =
3409 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3411 # Save the currently selected filehandle and
3412 # force output to debugger's filehandle (dumpvar
3413 # just does "print" for output).
3414 my $savout = select($OUT);
3416 # Grab package name and variables to dump.
3417 $packname = $new_packname;
3418 my @vars = split( ' ', $new_vars_str );
3420 # If main::dumpvar isn't here, get it.
3421 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3422 if ( defined &main::dumpvar ) {
3424 # We got it. Turn off subroutine entry/exit messages
3425 # for the moment, along with return values.
3429 # must detect sigpipe failures - not catching
3430 # then will cause the debugger to die.
3434 defined $option{dumpDepth}
3435 ? $option{dumpDepth}
3436 : -1, # assume -1 unless specified
3441 # The die doesn't need to include the $@, because
3442 # it will automatically get propagated for us.
3444 die unless $@ =~ /dumpvar print failed/;
3446 } ## end if (defined &main::dumpvar)
3449 # Couldn't load dumpvar.
3450 print $OUT "dumpvar.pl not available.\n";
3453 # Restore the output filehandle, and go round again.
3461 sub _handle_dash_command {
3464 if ($self->_is_full('-')) {
3466 # back up by a window; go to 1 if back too far.
3467 $start -= $incr + $window + 1;
3468 $start = 1 if $start <= 0;
3469 $incr = $window - 1;
3471 # Generate and execute a "l +" command (handled below).
3472 $DB::cmd = 'l ' . ($start) . '+';
3478 sub _n_or_s_commands_generic {
3479 my ($self, $new_val) = @_;
3481 next CMD if DB::_DB__is_finished();
3483 # Single step, but don't enter subs.
3486 # Save for empty command (repeat last).
3487 $laststep = $DB::cmd;
3492 my ($self, $letter, $new_val) = @_;
3494 if ($self->_is_full($letter)) {
3495 $self->_n_or_s_commands_generic($new_val);
3498 $self->_n_or_s_and_arg_commands_generic($letter, $new_val);
3504 sub _handle_n_command {
3507 return $self->_n_or_s('n', 2);
3510 sub _handle_s_command {
3513 return $self->_n_or_s('s', 1);
3516 sub _handle_r_command {
3519 # r - return from the current subroutine.
3520 if ($self->_is_full('r')) {
3522 # Can't do anything if the program's over.
3523 next CMD if DB::_DB__is_finished();
3525 # Turn on stack trace.
3526 $stack[$stack_depth] |= 1;
3528 # Print return value unless the stack is empty.
3529 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3536 sub _handle_T_command {
3539 if ($self->_is_full('T')) {
3540 DB::print_trace( $OUT, 1 ); # skip DB
3547 sub _handle_w_command {
3550 DB::cmd_w( 'w', $self->cmd_args() );
3556 sub _handle_W_command {
3559 if (my $arg = $self->cmd_args) {
3560 DB::cmd_W( 'W', $arg );
3567 sub _handle_rc_recall_command {
3570 # $rc - recall command.
3571 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3573 # No arguments, take one thing off history.
3574 pop(@hist) if length($DB::cmd) > 1;
3576 # Relative (- found)?
3577 # Y - index back from most recent (by 1 if bare minus)
3578 # N - go to that particular command slot or the last
3579 # thing if nothing following.
3582 scalar($minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist ))
3585 # Pick out the command desired.
3586 $DB::cmd = $hist[$self->cmd_verb];
3588 # Print the command to be executed and restart the loop
3589 # with that command in the buffer.
3590 print {$OUT} $DB::cmd, "\n";
3597 sub _handle_rc_search_history_command {
3600 # $rc pattern $rc - find a command in the history.
3601 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) {
3603 # Create the pattern to use.
3607 # Toss off last entry if length is >1 (and it always is).
3608 pop(@hist) if length($DB::cmd) > 1;
3612 # Look backward through the history.
3614 for ( $i = $#hist ; $i ; --$i ) {
3615 # Stop if we find it.
3616 last SEARCH_HIST if $hist[$i] =~ /$pat/;
3622 print $OUT "No such command!\n\n";
3626 # Found it. Put it in the buffer, print it, and process it.
3627 $DB::cmd = $hist[$i];
3628 print $OUT $DB::cmd, "\n";
3635 sub _handle_H_command {
3638 if ($self->cmd_args =~ m#\A\*#) {
3639 @hist = @truehist = ();
3640 print $OUT "History cleansed\n";
3644 if (my ($num) = $self->cmd_args =~ /\A(?:-(\d+))?/) {
3646 # Anything other than negative numbers is ignored by
3647 # the (incorrect) pattern, so this test does nothing.
3648 $end = $num ? ( $#hist - $num ) : 0;
3650 # Set to the minimum if less than zero.
3651 $hist = 0 if $hist < 0;
3653 # Start at the end of the array.
3654 # Stay in while we're still above the ending value.
3655 # Tick back by one each time around the loop.
3658 for ( $i = $#hist ; $i > $end ; $i-- ) {
3660 # Print the command unless it has no arguments.
3661 print $OUT "$i: ", $hist[$i], "\n"
3662 unless $hist[$i] =~ /^.?$/;
3671 sub _handle_doc_command {
3674 # man, perldoc, doc - show manual pages.
3676 = $DB::cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
3684 sub _handle_p_command {
3687 my $print_cmd = 'print {$DB::OUT} ';
3688 # p - print (no args): print $_.
3689 if ($self->_is_full('p')) {
3690 $DB::cmd = $print_cmd . '$_';
3693 # p - print the given expression.
3694 $DB::cmd =~ s/\Ap\b/$print_cmd /;
3700 sub _handle_equal_sign_command {
3703 if ($DB::cmd =~ s/\A=\s*//) {
3705 if ( length $DB::cmd == 0 ) {
3707 # No args, get current aliases.
3708 @keys = sort keys %alias;
3710 elsif ( my ( $k, $v ) = ( $DB::cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3712 # Creating a new alias. $k is alias name, $v is
3715 # can't use $_ or kill //g state
3716 for my $x ( $k, $v ) {
3718 # Escape "alarm" characters.
3722 # Substitute key for value, using alarm chars
3723 # as separators (which is why we escaped them in
3725 $alias{$k} = "s\a$k\a$v\a";
3727 # Turn off standard warn and die behavior.
3728 local $SIG{__DIE__};
3729 local $SIG{__WARN__};
3732 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3734 # Nope. Bad alias. Say so and get out.
3735 print $OUT "Can't alias $k to $v: $@\n";
3740 # We'll only list the new one.
3742 } ## end elsif (my ($k, $v) = ($DB::cmd...
3744 # The argument is the alias to list.
3752 # Messy metaquoting: Trim the substitution code off.
3753 # We use control-G as the delimiter because it's not
3754 # likely to appear in the alias.
3755 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3758 print $OUT "$k\t= $1\n";
3760 elsif ( defined $alias{$k} ) {
3762 # Couldn't trim it off; just print the alias code.
3763 print $OUT "$k\t$alias{$k}\n";
3768 print "No alias for $k\n";
3770 } ## end for my $k (@keys)
3777 sub _handle_source_command {
3780 # source - read commands from a file (or pipe!) and execute.
3781 if (my $sourced_fn = $self->cmd_args) {
3782 if ( open my $fh, $sourced_fn ) {
3784 # Opened OK; stick it in the list of file handles.
3790 DB::_db_warn("Can't execute '$sourced_fn': $!\n");
3798 sub _handle_enable_disable_commands {
3801 my $which_cmd = $self->cmd_verb;
3802 my $position = $self->cmd_args;
3804 if ($position !~ /\s/) {
3805 my ($fn, $line_num);
3806 if ($position =~ m{\A\d+\z})
3808 $fn = $DB::filename;
3809 $line_num = $position;
3811 elsif (my ($new_fn, $new_line_num)
3812 = $position =~ m{\A(.*):(\d+)\z}) {
3813 ($fn, $line_num) = ($new_fn, $new_line_num);
3817 DB::_db_warn("Wrong spec for enable/disable argument.\n");
3821 if (DB::_has_breakpoint_data_ref($fn, $line_num)) {
3822 DB::_set_breakpoint_enabled_status($fn, $line_num,
3823 ($which_cmd eq 'enable' ? 1 : '')
3827 DB::_db_warn("No breakpoint set at ${fn}:${line_num}\n");
3837 sub _handle_save_command {
3840 if (my $new_fn = $self->cmd_args) {
3841 my $filename = $new_fn || '.perl5dbrc'; # default?
3842 if ( open my $fh, '>', $filename ) {
3844 # chomp to remove extraneous newlines from source'd files
3845 chomp( my @truelist =
3846 map { m/\A\s*(save|source)/ ? "#$_" : $_ }
3848 print {$fh} join( "\n", @truelist );
3849 print "commands saved in $filename\n";
3852 DB::_db_warn("Can't save debugger commands in '$new_fn': $!\n");
3860 sub _n_or_s_and_arg_commands_generic {
3861 my ($self, $letter, $new_val) = @_;
3863 # s - single-step. Remember the last command was 's'.
3864 if ($DB::cmd =~ s#\A\Q$letter\E\s#\$DB::single = $new_val;\n#) {
3865 $laststep = $letter;
3871 sub _handle_sh_command {
3874 # $sh$sh - run a shell command (if it's all ASCII).
3875 # Can't run shell commands with Unicode in the debugger, hmm.
3876 my $my_cmd = $DB::cmd;
3877 if ($my_cmd =~ m#\A$sh#gms) {
3879 if ($my_cmd =~ m#\G\z#cgms) {
3880 # Run the user's shell. If none defined, run Bourne.
3881 # We resume execution when the shell terminates.
3882 DB::_db_system( $ENV{SHELL} || "/bin/sh" );
3885 elsif ($my_cmd =~ m#\G$sh\s*(.*)#cgms) {
3890 elsif ($my_cmd =~ m#\G\s*(.*)#cgms) {
3891 DB::_db_system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3897 sub _handle_x_command {
3900 if ($DB::cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
3901 $onetimeDump = 'dump'; # main::dumpvar shows the output
3903 # handle special "x 3 blah" syntax XXX propagate
3904 # doc back to special variables.
3905 if ( $DB::cmd =~ s#\A\s*(\d+)(?=\s)# #) {
3906 $onetimedumpDepth = $1;
3913 sub _handle_q_command {
3916 if ($self->_is_full('q')) {
3925 sub _handle_cmd_wrapper_commands {
3928 DB::cmd_wrapper( $self->cmd_verb, $self->cmd_args, $line );
3932 sub _handle_special_char_cmd_wrapper_commands {
3935 # All of these commands were remapped in perl 5.8.0;
3936 # we send them off to the secondary dispatcher (see below).
3937 if (my ($cmd_letter, $my_arg) = $DB::cmd =~ /\A([<>\{]{1,2})\s*(.*)/so) {
3938 DB::cmd_wrapper( $cmd_letter, $my_arg, $line );
3947 # The following code may be executed now:
3952 C<sub> is called whenever a subroutine call happens in the program being
3953 debugged. The variable C<$DB::sub> contains the name of the subroutine
3956 The core function of this subroutine is to actually call the sub in the proper
3957 context, capturing its output. This of course causes C<DB::DB> to get called
3958 again, repeating until the subroutine ends and returns control to C<DB::sub>
3959 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3960 return value, and returns its captured copy of the return value as its own
3961 return value. The value then feeds back into the program being debugged as if
3962 C<DB::sub> hadn't been there at all.
3964 C<sub> does all the work of printing the subroutine entry and exit messages
3965 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3966 and also prints the return value if needed (for the C<r> command and if
3967 the 16 bit is set in C<$frame>).
3969 It also tracks the subroutine call depth by saving the current setting of
3970 C<$single> in the C<@stack> package global; if this exceeds the value in
3971 C<$deep>, C<sub> automatically turns on printing of the current depth by
3972 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
3973 of stop/don't stop on entry to subs set as it currently is set.
3975 =head3 C<caller()> support
3977 If C<caller()> is called from the package C<DB>, it provides some
3978 additional data, in the following order:
3984 The package name the sub was in
3986 =item * C<$filename>
3988 The filename it was defined in
3992 The line number it was defined on
3994 =item * C<$subroutine>
3996 The subroutine name; C<(eval)> if an C<eval>().
4000 1 if it has arguments, 0 if not
4002 =item * C<$wantarray>
4004 1 if array context, 0 if scalar context
4006 =item * C<$evaltext>
4008 The C<eval>() text, if any (undefined for C<eval BLOCK>)
4010 =item * C<$is_require>
4012 frame was created by a C<use> or C<require> statement
4016 pragma information; subject to change between versions
4020 pragma information; subject to change between versions
4022 =item * C<@DB::args>
4024 arguments with which the subroutine was invoked
4032 # We need to fully qualify the name ("DB::sub") to make "use strict;"
4033 # happy. -- Shlomi Fish
4036 # Do not use a regex in this subroutine -> results in corrupted memory
4037 # See: [perl #66110]
4039 # lock ourselves under threads
4042 # Whether or not the autoloader was running, a scalar to put the
4043 # sub's return value in (if needed), and an array to put the sub's
4044 # return value in (if needed).
4045 my ( $al, $ret, @ret ) = "";
4046 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
4047 print "creating new thread\n";
4050 # If the last ten characters are '::AUTOLOAD', note we've traced
4051 # into AUTOLOAD for $sub.
4052 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4054 $al = " for $$sub" if defined $$sub;
4057 # We stack the stack pointer and then increment it to protect us
4058 # from a situation that might unwind a whole bunch of call frames
4059 # at once. Localizing the stack pointer means that it will automatically
4060 # unwind the same amount when multiple stack frames are unwound.
4061 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4064 $#stack = $stack_depth;
4066 # Save current single-step setting.
4067 $stack[-1] = $single;
4069 # Turn off all flags except single-stepping.
4072 # If we've gotten really deeply recursed, turn on the flag that will
4073 # make us stop with the 'deep recursion' message.
4074 $single |= 4 if $stack_depth == $deep;
4076 # If frame messages are on ...
4078 $frame & 4 # Extended frame entry message
4080 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
4082 # Why -1? But it works! :-(
4083 # Because print_trace will call add 1 to it and then call
4084 # dump_trace; this results in our skipping -1+1 = 0 stack frames
4086 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
4088 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
4090 # standard frame entry message
4094 my $print_exit_msg = sub {
4095 # Check for exit trace messages...
4098 if ($frame & 4) # Extended exit message
4100 print_lineinfo( ' ' x $stack_depth, "out " );
4101 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" );
4105 print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" );
4111 # Determine the sub's return type, and capture appropriately.
4114 # Called in array context. call sub and capture output.
4115 # DB::DB will recursively get control again if appropriate; we'll come
4116 # back here when the sub is finished.
4122 # Pop the single-step value back off the stack.
4123 $single |= $stack[ $stack_depth-- ];
4125 $print_exit_msg->();
4127 # Print the return info if we need to.
4128 if ( $doret eq $stack_depth or $frame & 16 ) {
4130 # Turn off output record separator.
4132 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4134 # Indent if we're printing because of $frame tracing.
4137 print {$fh} ' ' x $stack_depth;
4140 # Print the return value.
4141 print {$fh} "list context return from $sub:\n";
4142 dumpit( $fh, \@ret );
4144 # And don't print it again.
4146 } ## end if ($doret eq $stack_depth...
4147 # And we have to return the return value now.
4149 } ## end if (wantarray)
4153 if ( defined wantarray ) {
4155 # Save the value if it's wanted at all.
4160 # Void return, explicitly.
4165 # Pop the single-step value off the stack.
4166 $single |= $stack[ $stack_depth-- ];
4168 # If we're doing exit messages...
4169 $print_exit_msg->();
4171 # If we are supposed to show the return value... same as before.
4172 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
4174 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4175 print $fh ( ' ' x $stack_depth ) if $frame & 16;
4178 ? "scalar context return from $sub: "
4179 : "void context return from $sub\n"
4181 dumpit( $fh, $ret ) if defined wantarray;
4183 } ## end if ($doret eq $stack_depth...
4185 # Return the appropriate scalar value.
4187 } ## end else [ if (wantarray)
4194 # lock ourselves under threads
4197 # Whether or not the autoloader was running, a scalar to put the
4198 # sub's return value in (if needed), and an array to put the sub's
4199 # return value in (if needed).
4200 my ( $al, $ret, @ret ) = "";
4201 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
4202 print "creating new thread\n";
4205 # If the last ten characters are C'::AUTOLOAD', note we've traced
4206 # into AUTOLOAD for $sub.
4207 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4211 # We stack the stack pointer and then increment it to protect us
4212 # from a situation that might unwind a whole bunch of call frames
4213 # at once. Localizing the stack pointer means that it will automatically
4214 # unwind the same amount when multiple stack frames are unwound.
4215 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4218 $#stack = $stack_depth;
4220 # Save current single-step setting.
4221 $stack[-1] = $single;
4223 # Turn off all flags except single-stepping.
4226 # If we've gotten really deeply recursed, turn on the flag that will
4227 # make us stop with the 'deep recursion' message.
4228 $single |= 4 if $stack_depth == $deep;
4230 # If frame messages are on ...
4232 $frame & 4 # Extended frame entry message
4234 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
4236 # Why -1? But it works! :-(
4237 # Because print_trace will call add 1 to it and then call
4238 # dump_trace; this results in our skipping -1+1 = 0 stack frames
4240 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
4242 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
4244 # standard frame entry message
4248 # Pop the single-step value back off the stack.
4249 $single |= $stack[ $stack_depth-- ];
4251 # call the original lvalue sub.
4255 # Abstracting common code from multiple places elsewhere:
4256 sub depth_print_lineinfo {
4257 my $always_print = shift;
4259 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth);
4262 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
4264 In Perl 5.8.0, there was a major realignment of the commands and what they did,
4265 Most of the changes were to systematize the command structure and to eliminate
4266 commands that threw away user input without checking.
4268 The following sections describe the code added to make it easy to support
4269 multiple command sets with conflicting command names. This section is a start
4270 at unifying all command processing to make it simpler to develop commands.
4272 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
4273 number, and C<$dbline> (the current line) as arguments.
4275 Support functions in this section which have multiple modes of failure C<die>
4276 on error; the rest simply return a false value.
4278 The user-interface functions (all of the C<cmd_*> functions) just output
4283 The C<%set> hash defines the mapping from command letter to subroutine
4286 C<%set> is a two-level hash, indexed by set name and then by command name.
4287 Note that trying to set the CommandSet to C<foobar> simply results in the
4288 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
4297 'A' => 'pre580_null',
4299 'B' => 'pre580_null',
4300 'd' => 'pre580_null',
4303 'M' => 'pre580_null',
4305 'o' => 'pre580_null',
4311 '<' => 'pre590_prepost',
4312 '<<' => 'pre590_prepost',
4313 '>' => 'pre590_prepost',
4314 '>>' => 'pre590_prepost',
4315 '{' => 'pre590_prepost',
4316 '{{' => 'pre590_prepost',
4320 my %breakpoints_data;
4322 sub _has_breakpoint_data_ref {
4323 my ($filename, $line) = @_;
4326 exists( $breakpoints_data{$filename} )
4328 exists( $breakpoints_data{$filename}{$line} )
4332 sub _get_breakpoint_data_ref {
4333 my ($filename, $line) = @_;
4335 return ($breakpoints_data{$filename}{$line} ||= +{});
4338 sub _delete_breakpoint_data_ref {
4339 my ($filename, $line) = @_;
4341 delete($breakpoints_data{$filename}{$line});
4342 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) {
4343 delete($breakpoints_data{$filename});
4349 sub _set_breakpoint_enabled_status {
4350 my ($filename, $line, $status) = @_;
4352 _get_breakpoint_data_ref($filename, $line)->{'enabled'} =
4359 sub _enable_breakpoint_temp_enabled_status {
4360 my ($filename, $line) = @_;
4362 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1;
4367 sub _cancel_breakpoint_temp_enabled_status {
4368 my ($filename, $line) = @_;
4370 my $ref = _get_breakpoint_data_ref($filename, $line);
4372 delete ($ref->{'temp_enabled'});
4375 _delete_breakpoint_data_ref($filename, $line);
4381 sub _is_breakpoint_enabled {
4382 my ($filename, $line) = @_;
4384 my $data_ref = _get_breakpoint_data_ref($filename, $line);
4385 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'});
4388 =head2 C<cmd_wrapper()> (API)
4390 C<cmd_wrapper()> allows the debugger to switch command sets
4391 depending on the value of the C<CommandSet> option.
4393 It tries to look up the command in the C<%set> package-level I<lexical>
4394 (which means external entities can't fiddle with it) and create the name of
4395 the sub to call based on the value found in the hash (if it's there). I<All>
4396 of the commands to be handled in a set have to be added to C<%set>; if they
4397 aren't found, the 5.8.0 equivalent is called (if there is one).
4399 This code uses symbolic references.
4406 my $dblineno = shift;
4408 # Assemble the command subroutine's name by looking up the
4409 # command set and command name in %set. If we can't find it,
4410 # default to the older version of the command.
4412 . ( $set{$CommandSet}{$cmd}
4413 || ( $cmd =~ /\A[<>{]+/o ? 'prepost' : $cmd ) );
4415 # Call the command subroutine, call it by name.
4416 return __PACKAGE__->can($call)->( $cmd, $line, $dblineno );
4417 } ## end sub cmd_wrapper
4419 =head3 C<cmd_a> (command)
4421 The C<a> command handles pre-execution actions. These are associated with a
4422 particular line, so they're stored in C<%dbline>. We default to the current
4423 line if none is specified.
4429 my $line = shift || ''; # [.|line] expr
4432 # If it's dot (here), or not all digits, use the current line.
4433 $line =~ s/\A\./$dbline/;
4435 # Should be a line number followed by an expression.
4436 if ( my ($lineno, $expr) = $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
4438 if (! length($lineno)) {
4442 # If we have an expression ...
4443 if ( length $expr ) {
4445 # ... but the line isn't breakable, complain.
4446 if ( $dbline[$lineno] == 0 ) {
4448 "Line $lineno($dbline[$lineno]) does not have an action?\n";
4452 # It's executable. Record that the line has an action.
4453 $had_breakpoints{$filename} |= 2;
4455 # Remove any action, temp breakpoint, etc.
4456 $dbline{$lineno} =~ s/\0[^\0]*//;
4458 # Add the action to the line.
4459 $dbline{$lineno} .= "\0" . action($expr);
4461 _set_breakpoint_enabled_status($filename, $lineno, 1);
4463 } ## end if (length $expr)
4464 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
4469 "Adding an action requires an optional lineno and an expression\n"
4474 =head3 C<cmd_A> (command)
4476 Delete actions. Similar to above, except the delete code is in a separate
4477 subroutine, C<delete_action>.
4483 my $line = shift || '';
4487 $line =~ s/^\./$dbline/;
4489 # Call delete_action with a null param to delete them all.
4490 # The '1' forces the eval to be true. It'll be false only
4491 # if delete_action blows up for some reason, in which case
4492 # we print $@ and get out.
4493 if ( $line eq '*' ) {
4494 if (! eval { _delete_all_actions(); 1 }) {
4500 # There's a real line number. Pass it to delete_action.
4501 # Error trapping is as above.
4502 elsif ( $line =~ /^(\S.*)/ ) {
4503 if (! eval { delete_action($1); 1 }) {
4509 # Swing and a miss. Bad syntax.
4512 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4516 =head3 C<delete_action> (API)
4518 C<delete_action> accepts either a line number or C<undef>. If a line number
4519 is specified, we check for the line being executable (if it's not, it
4520 couldn't have had an action). If it is, we just take the action off (this
4521 will get any kind of an action, including breakpoints).
4525 sub _remove_action_from_dbline {
4528 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4529 delete $dbline{$i} if $dbline{$i} eq '';
4534 sub _delete_all_actions {
4535 print {$OUT} "Deleting all actions...\n";
4537 for my $file ( keys %had_breakpoints ) {
4538 local *dbline = $main::{ '_<' . $file };
4541 for my $i (1 .. $max) {
4542 if ( defined $dbline{$i} ) {
4543 _remove_action_from_dbline($i);
4547 unless ( $had_breakpoints{$file} &= ~2 ) {
4548 delete $had_breakpoints{$file};
4558 if ( defined($i) ) {
4560 die "Line $i has no action .\n" if $dbline[$i] == 0;
4562 # Nuke whatever's there.
4563 _remove_action_from_dbline($i);
4566 _delete_all_actions();
4570 =head3 C<cmd_b> (command)
4572 Set breakpoints. Since breakpoints can be set in so many places, in so many
4573 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4574 we try to parse the command type, and then shuttle it off to an appropriate
4575 subroutine to actually do the work of setting the breakpoint in the right
4582 my $line = shift; # [.|line] [cond]
4585 my $default_cond = sub {
4587 return length($cond) ? $cond : '1';
4590 # Make . the current line number if it's there..
4591 $line =~ s/^\.(\s|\z)/$dbline$1/;
4593 # No line number, no condition. Simple break on current line.
4594 if ( $line =~ /^\s*$/ ) {
4595 cmd_b_line( $dbline, 1 );
4598 # Break on load for a file.
4599 elsif ( my ($file) = $line =~ /^load\b\s*(.*)/ ) {
4604 # b compile|postpone <some sub> [<condition>]
4605 # The interpreter actually traps this one for us; we just put the
4606 # necessary condition in the %postponed hash.
4607 elsif ( my ($action, $subname, $cond)
4608 = $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4610 # De-Perl4-ify the name - ' separators to ::.
4611 $subname =~ s/'/::/g;
4613 # Qualify it into the current package unless it's already qualified.
4614 $subname = "${package}::" . $subname unless $subname =~ /::/;
4616 # Add main if it starts with ::.
4617 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4619 # Save the break type for this sub.
4620 $postponed{$subname} = (($action eq 'postpone')
4621 ? ( "break +0 if " . $default_cond->($cond) )
4623 } ## end elsif ($line =~ ...
4624 # b <filename>:<line> [<condition>]
4625 elsif (my ($filename, $line_num, $cond)
4626 = $line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) {
4627 cmd_b_filename_line(
4630 (length($cond) ? $cond : '1'),
4633 # b <sub name> [<condition>]
4634 elsif ( my ($new_subname, $new_cond) =
4635 $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4638 $subname = $new_subname;
4639 cmd_b_sub( $subname, $default_cond->($new_cond) );
4642 # b <line> [<condition>].
4643 elsif ( my ($line_n, $cond) = $line =~ /^(\d*)\s*(.*)/ ) {
4645 # Capture the line. If none, it's the current line.
4646 $line = $line_n || $dbline;
4649 cmd_b_line( $line, $default_cond->($cond) );
4652 # Line didn't make sense.
4654 print "confused by line($line)?\n";
4660 =head3 C<break_on_load> (API)
4662 We want to break when this file is loaded. Mark this file in the
4663 C<%break_on_load> hash, and note that it has a breakpoint in
4664 C<%had_breakpoints>.
4670 $break_on_load{$file} = 1;
4671 $had_breakpoints{$file} |= 1;
4674 =head3 C<report_break_on_load> (API)
4676 Gives us an array of filenames that are set to break on load. Note that
4677 only files with break-on-load are in here, so simply showing the keys
4682 sub report_break_on_load {
4683 sort keys %break_on_load;
4686 =head3 C<cmd_b_load> (command)
4688 We take the file passed in and try to find it in C<%INC> (which maps modules
4689 to files they came from). We mark those files for break-on-load via
4690 C<break_on_load> and then report that it was done.
4698 # This is a block because that way we can use a redo inside it
4699 # even without there being any looping structure at all outside it.
4702 # Save short name and full path if found.
4704 push @files, $::INC{$file} if $::INC{$file};
4706 # Tack on .pm and do it again unless there was a '.' in the name
4708 $file .= '.pm', redo unless $file =~ /\./;
4711 # Do the real work here.
4712 break_on_load($_) for @files;
4714 # All the files that have break-on-load breakpoints.
4715 @files = report_break_on_load;
4717 # Normalize for the purposes of our printing this.
4720 print $OUT "Will stop on load of '@files'.\n";
4721 } ## end sub cmd_b_load
4723 =head3 C<$filename_error> (API package global)
4725 Several of the functions we need to implement in the API need to work both
4726 on the current file and on other files. We don't want to duplicate code, so
4727 C<$filename_error> is used to contain the name of the file that's being
4728 worked on (if it's not the current one).
4730 We can now build functions in pairs: the basic function works on the current
4731 file, and uses C<$filename_error> as part of its error message. Since this is
4732 initialized to C<"">, no filename will appear when we are working on the
4735 The second function is a wrapper which does the following:
4741 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4745 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4749 Calls the first function.
4751 The first function works on the I<current> file (i.e., the one we changed to),
4752 and prints C<$filename_error> in the error message (the name of the other file)
4753 if it needs to. When the functions return, C<*dbline> is restored to point
4754 to the actual current file (the one we're executing in) and
4755 C<$filename_error> is restored to C<"">. This restores everything to
4756 the way it was before the second function was called at all.
4758 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4765 use vars qw($filename_error);
4766 $filename_error = '';
4768 =head3 breakable_line(from, to) (API)
4770 The subroutine decides whether or not a line in the current file is breakable.
4771 It walks through C<@dbline> within the range of lines specified, looking for
4772 the first line that is breakable.
4774 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4775 first line I<after> C<$to> that's breakable, if there is one.
4777 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4778 first line I<before> C<$to> that's breakable, if there is one.
4782 sub breakable_line {
4784 my ( $from, $to ) = @_;
4786 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4789 # If there are at least 2 arguments, we're trying to search a range.
4792 # $delta is positive for a forward search, negative for a backward one.
4793 my $delta = $from < $to ? +1 : -1;
4795 # Keep us from running off the ends of the file.
4796 my $limit = $delta > 0 ? $#dbline : 1;
4798 # Clever test. If you're a mathematician, it's obvious why this
4799 # test works. If not:
4800 # If $delta is positive (going forward), $limit will be $#dbline.
4801 # If $to is less than $limit, ($limit - $to) will be positive, times
4802 # $delta of 1 (positive), so the result is > 0 and we should use $to
4803 # as the stopping point.
4805 # If $to is greater than $limit, ($limit - $to) is negative,
4806 # times $delta of 1 (positive), so the result is < 0 and we should
4807 # use $limit ($#dbline) as the stopping point.
4809 # If $delta is negative (going backward), $limit will be 1.
4810 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4811 # (negative) so the result is > 0, and we use $to as the stopping
4814 # If $to is less than zero, ($limit - $to) will be positive,
4815 # times $delta of -1 (negative), so the result is not > 0, and
4816 # we use $limit (1) as the stopping point.
4818 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4819 # (negative), still giving zero; the result is not > 0, and
4820 # we use $limit (1) as the stopping point.
4822 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4823 # (negative), giving a positive (>0) value, so we'll set $limit to
4826 $limit = $to if ( $limit - $to ) * $delta > 0;
4828 # The real search loop.
4829 # $i starts at $from (the point we want to start searching from).
4830 # We move through @dbline in the appropriate direction (determined
4831 # by $delta: either -1 (back) or +1 (ahead).
4832 # We stay in as long as we haven't hit an executable line
4833 # ($dbline[$i] == 0 means not executable) and we haven't reached
4834 # the limit yet (test similar to the above).
4835 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4837 } ## end if (@_ >= 2)
4839 # If $i points to a line that is executable, return that.
4840 return $i unless $dbline[$i] == 0;
4842 # Format the message and print it: no breakable lines in range.
4843 my ( $pl, $upto ) = ( '', '' );
4844 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4846 # If there's a filename in filename_error, we'll see it.
4848 die "Line$pl $from$upto$filename_error not breakable\n";
4849 } ## end sub breakable_line
4851 =head3 breakable_line_in_filename(file, from, to) (API)
4853 Like C<breakable_line>, but look in another file.
4857 sub breakable_line_in_filename {
4859 # Capture the file name.
4862 # Swap the magic line array over there temporarily.
4863 local *dbline = $main::{ '_<' . $f };
4865 # If there's an error, it's in this other file.
4866 local $filename_error = " of '$f'";
4868 # Find the breakable line.
4871 # *dbline and $filename_error get restored when this block ends.
4873 } ## end sub breakable_line_in_filename
4875 =head3 break_on_line(lineno, [condition]) (API)
4877 Adds a breakpoint with the specified condition (or 1 if no condition was
4878 specified) to the specified line. Dies if it can't.
4884 my $cond = @_ ? shift(@_) : 1;
4890 # Woops, not a breakable line. $filename_error allows us to say
4891 # if it was in a different file.
4892 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4894 # Mark this file as having breakpoints in it.
4895 $had_breakpoints{$filename} |= 1;
4897 # If there is an action or condition here already ...
4898 if ( $dbline{$i} ) {
4900 # ... swap this condition for the existing one.
4901 $dbline{$i} =~ s/^[^\0]*/$cond/;
4905 # Nothing here - just add the condition.
4906 $dbline{$i} = $cond;
4908 _set_breakpoint_enabled_status($filename, $i, 1);
4912 } ## end sub break_on_line
4914 =head3 cmd_b_line(line, [condition]) (command)
4916 Wrapper for C<break_on_line>. Prints the failure message if it
4922 if (not eval { break_on_line(@_); 1 }) {
4924 print $OUT $@ and return;
4928 } ## end sub cmd_b_line
4930 =head3 cmd_b_filename_line(line, [condition]) (command)
4932 Wrapper for C<break_on_filename_line>. Prints the failure message if it
4937 sub cmd_b_filename_line {
4938 if (not eval { break_on_filename_line(@_); 1 }) {
4940 print $OUT $@ and return;
4946 =head3 break_on_filename_line(file, line, [condition]) (API)
4948 Switches to the file specified and then calls C<break_on_line> to set
4953 sub break_on_filename_line {
4956 my $cond = @_ ? shift(@_) : 1;
4958 # Switch the magical hash temporarily.
4959 local *dbline = $main::{ '_<' . $f };
4961 # Localize the variables that break_on_line uses to make its message.
4962 local $filename_error = " of '$f'";
4963 local $filename = $f;
4965 # Add the breakpoint.
4966 break_on_line( $i, $cond );
4969 } ## end sub break_on_filename_line
4971 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4973 Switch to another file, search the range of lines specified for an
4974 executable one, and put a breakpoint on the first one you find.
4978 sub break_on_filename_line_range {
4982 my $cond = @_ ? shift(@_) : 1;
4984 # Find a breakable line if there is one.
4985 my $i = breakable_line_in_filename( $f, $from, $to );
4987 # Add the breakpoint.
4988 break_on_filename_line( $f, $i, $cond );
4991 } ## end sub break_on_filename_line_range
4993 =head3 subroutine_filename_lines(subname, [condition]) (API)
4995 Search for a subroutine within a given file. The condition is ignored.
4996 Uses C<find_sub> to locate the desired subroutine.
5000 sub subroutine_filename_lines {
5001 my ( $subname ) = @_;
5003 # Returned value from find_sub() is fullpathname:startline-endline.
5004 # The match creates the list (fullpathname, start, end).
5005 return (find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/);
5006 } ## end sub subroutine_filename_lines
5008 =head3 break_subroutine(subname) (API)
5010 Places a break on the first line possible in the specified subroutine. Uses
5011 C<subroutine_filename_lines> to find the subroutine, and
5012 C<break_on_filename_line_range> to place the break.
5016 sub break_subroutine {
5017 my $subname = shift;
5019 # Get filename, start, and end.
5020 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
5021 or die "Subroutine $subname not found.\n";
5024 # Null condition changes to '1' (always true).
5025 my $cond = @_ ? shift(@_) : 1;
5027 # Put a break the first place possible in the range of lines
5028 # that make up this subroutine.
5029 break_on_filename_line_range( $file, $s, $e, $cond );
5032 } ## end sub break_subroutine
5034 =head3 cmd_b_sub(subname, [condition]) (command)
5036 We take the incoming subroutine name and fully-qualify it as best we can.
5040 =item 1. If it's already fully-qualified, leave it alone.
5042 =item 2. Try putting it in the current package.
5044 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
5046 =item 4. If it starts with '::', put it in 'main::'.
5050 After all this cleanup, we call C<break_subroutine> to try to set the
5056 my ( $subname, $cond ) = @_;
5058 # Add always-true condition if we have none.
5059 $cond = 1 unless @_ >= 2;
5061 # If the subname isn't a code reference, qualify it so that
5062 # break_subroutine() will work right.
5063 unless ( ref $subname eq 'CODE' ) {
5066 $subname =~ s/\'/::/g;
5069 # Put it in this package unless it's already qualified.
5070 $subname = "${package}::" . $subname
5071 unless $subname =~ /::/;
5073 # Requalify it into CORE::GLOBAL if qualifying it into this
5074 # package resulted in its not being defined, but only do so
5075 # if it really is in CORE::GLOBAL.
5076 $subname = "CORE::GLOBAL::$s"
5077 if not defined &$subname
5079 and defined &{"CORE::GLOBAL::$s"};
5081 # Put it in package 'main' if it has a leading ::.
5082 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
5084 } ## end unless (ref $subname eq 'CODE')
5086 # Try to set the breakpoint.
5087 if (not eval { break_subroutine( $subname, $cond ); 1 }) {
5089 print $OUT $@ and return;
5093 } ## end sub cmd_b_sub
5095 =head3 C<cmd_B> - delete breakpoint(s) (command)
5097 The command mostly parses the command line and tries to turn the argument
5098 into a line spec. If it can't, it uses the current line. It then calls
5099 C<delete_breakpoint> to actually do the work.
5101 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
5102 thereby deleting all the breakpoints.
5109 # No line spec? Use dbline.
5110 # If there is one, use it if it's non-zero, or wipe it out if it is.
5111 my $line = ( $_[0] =~ /\A\./ ) ? $dbline : (shift || '');
5114 # If the line was dot, make the line the current one.
5115 $line =~ s/^\./$dbline/;
5117 # If it's * we're deleting all the breakpoints.
5118 if ( $line eq '*' ) {
5119 if (not eval { delete_breakpoint(); 1 }) {
5124 # If there is a line spec, delete the breakpoint on that line.
5125 elsif ( $line =~ /\A(\S.*)/ ) {
5126 if (not eval { delete_breakpoint( $line || $dbline ); 1 }) {
5130 } ## end elsif ($line =~ /^(\S.*)/)
5135 "Deleting a breakpoint requires a line number, or '*' for all\n"
5142 =head3 delete_breakpoint([line]) (API)
5144 This actually does the work of deleting either a single breakpoint, or all
5147 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
5148 just drop out with a message saying so. If it is, we remove the condition
5149 part of the 'condition\0action' that says there's a breakpoint here. If,
5150 after we've done that, there's nothing left, we delete the corresponding
5151 line in C<%dbline> to signal that no action needs to be taken for this line.
5153 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
5154 which lists all currently-loaded files which have breakpoints. We then look
5155 at each line in each of these files, temporarily switching the C<%dbline>
5156 and C<@dbline> structures to point to the files in question, and do what
5157 we did in the single line case: delete the condition in C<@dbline>, and
5158 delete the key in C<%dbline> if nothing's left.
5160 We then wholesale delete C<%postponed>, C<%postponed_file>, and
5161 C<%break_on_load>, because these structures contain breakpoints for files
5162 and code that haven't been loaded yet. We can just kill these off because there
5163 are no magical debugger structures associated with them.
5167 sub _remove_breakpoint_entry {
5171 _delete_breakpoint_data_ref($fn, $i);
5176 sub _delete_all_breakpoints {
5177 print {$OUT} "Deleting all breakpoints...\n";
5179 # %had_breakpoints lists every file that had at least one
5181 for my $fn ( keys %had_breakpoints ) {
5183 # Switch to the desired file temporarily.
5184 local *dbline = $main::{ '_<' . $fn };
5188 # For all lines in this file ...
5189 for my $i (1 .. $max) {
5191 # If there's a breakpoint or action on this line ...
5192 if ( defined $dbline{$i} ) {
5194 # ... remove the breakpoint.
5195 $dbline{$i} =~ s/\A[^\0]+//;
5196 if ( $dbline{$i} =~ s/\A\0?\z// ) {
5197 # Remove the entry altogether if no action is there.
5198 _remove_breakpoint_entry($fn, $i);
5200 } ## end if (defined $dbline{$i...
5201 } ## end for $i (1 .. $max)
5203 # If, after we turn off the "there were breakpoints in this file"
5204 # bit, the entry in %had_breakpoints for this file is zero,
5205 # we should remove this file from the hash.
5206 if ( not $had_breakpoints{$fn} &= (~1) ) {
5207 delete $had_breakpoints{$fn};
5209 } ## end for my $fn (keys %had_breakpoints)
5211 # Kill off all the other breakpoints that are waiting for files that
5212 # haven't been loaded yet.
5214 undef %postponed_file;
5215 undef %break_on_load;
5220 sub _delete_breakpoint_from_line {
5223 # Woops. This line wasn't breakable at all.
5224 die "Line $i not breakable.\n" if $dbline[$i] == 0;
5226 # Kill the condition, but leave any action.
5227 $dbline{$i} =~ s/\A[^\0]*//;
5229 # Remove the entry entirely if there's no action left.
5230 if ($dbline{$i} eq '') {
5231 _remove_breakpoint_entry($filename, $i);
5237 sub delete_breakpoint {
5240 # If we got a line, delete just that one.
5241 if ( defined($i) ) {
5242 _delete_breakpoint_from_line($i);
5244 # No line; delete them all.
5246 _delete_all_breakpoints();
5252 =head3 cmd_stop (command)
5254 This is meant to be part of the new command API, but it isn't called or used
5255 anywhere else in the debugger. XXX It is probably meant for use in development
5260 sub cmd_stop { # As on ^C, but not signal-safy.
5264 =head3 C<cmd_e> - threads
5266 Display the current thread id:
5270 This could be how (when implemented) to send commands to this thread id (e cmd)
5271 or that thread id (e tid cmd).
5278 unless (exists($INC{'threads.pm'})) {
5279 print "threads not loaded($ENV{PERL5DB_THREADED})
5280 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5282 my $tid = threads->tid;
5283 print "thread id: $tid\n";
5287 =head3 C<cmd_E> - list of thread ids
5289 Display the list of available thread ids:
5293 This could be used (when implemented) to send commands to all threads (E cmd).
5300 unless (exists($INC{'threads.pm'})) {
5301 print "threads not loaded($ENV{PERL5DB_THREADED})
5302 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5304 my $tid = threads->tid;
5305 print "thread ids: ".join(', ',
5306 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
5311 =head3 C<cmd_h> - help command (command)
5313 Does the work of either
5319 Showing all the debugger help
5323 Showing help for a specific command
5330 use vars qw($summary);
5335 # If we have no operand, assume null.
5336 my $line = shift || '';
5338 # 'h h'. Print the long-format help.
5339 if ( $line =~ /\Ah\s*\z/ ) {
5343 # 'h <something>'. Search for the command and print only its help.
5344 elsif ( my ($asked) = $line =~ /\A(\S.*)\z/ ) {
5346 # support long commands; otherwise bogus errors
5347 # happen when you ask for h on <CR> for example
5348 my $qasked = quotemeta($asked); # for searching; we don't
5349 # want to use it as a pattern.
5350 # XXX: finds CR but not <CR>
5352 # Search the help string for the command.
5354 $help =~ /^ # Start of a line
5356 (?:[IB]<) # Optional markup
5357 $qasked # The requested command
5362 # It's there; pull it out and print it.
5366 (?:[IB]<) # Optional markup
5367 $qasked # The command
5368 ([\s\S]*?) # Description line(s)
5369 \n) # End of last description line
5370 (?!\s) # Next line not starting with
5379 # Not found; not a debugger command.
5381 print_help("B<$asked> is not a debugger command.\n");
5383 } ## end elsif ($line =~ /^(\S.*)$/)
5385 # 'h' - print the summary help.
5387 print_help($summary);
5391 =head3 C<cmd_i> - inheritance display
5393 Display the (nested) parentage of the module or object given.
5400 foreach my $isa ( split( /\s+/, $line ) ) {
5402 ($isa) = DB::eval();
5409 defined( ${"$_\::VERSION"} )
5410 ? ' ' . ${"$_\::VERSION"}
5412 } @{mro::get_linear_isa(ref($isa) || $isa)}
5418 =head3 C<cmd_l> - list lines (command)
5420 Most of the command is taken up with transforming all the different line
5421 specification syntaxes into 'start-stop'. After that is done, the command
5422 runs a loop over C<@dbline> for the specified range of lines. It handles
5423 the printing of each line and any markers (C<==E<gt>> for current line,
5424 C<b> for break on this line, C<a> for action on this line, C<:> for this
5427 We save the last line listed in the C<$start> global for further listing
5433 my $current_line = $line;
5437 # If this is '-something', delete any spaces after the dash.
5438 $line =~ s/^-\s*$/-/;
5440 # If the line is '$something', assume this is a scalar containing a
5442 if ( $line =~ /^(\$.*)/s ) {
5444 # Set up for DB::eval() - evaluate in *user* context.
5447 my ($s) = DB::eval();
5449 # Ooops. Bad scalar.
5451 print {$OUT} "Error: $@\n";
5455 # Good scalar. If it's a reference, find what it points to.
5457 print {$OUT} "Interpreted as: $1 $s\n";
5460 # Call self recursively to really do the command.
5462 } ## end if ($line =~ /^(\$.*)/s)
5464 # l name. Try to find a sub by that name.
5465 elsif ( ($subname) = $line =~ /\A([\':A-Za-z_][\':\w]*(?:\[.*\])?)/s ) {
5469 $subname =~ s/\'/::/;
5471 # Put it in this package unless it starts with ::.
5472 $subname = $package . "::" . $subname unless $subname =~ /::/;
5474 # Put it in CORE::GLOBAL if t doesn't start with :: and
5475 # it doesn't live in this package and it lives in CORE::GLOBAL.
5476 $subname = "CORE::GLOBAL::$s"
5477 if not defined &$subname
5479 and defined &{"CORE::GLOBAL::$s"};
5481 # Put leading '::' names into 'main::'.
5482 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
5484 # Get name:start-stop from find_sub, and break this up at
5486 my @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
5488 # Pull off start-stop.
5489 my $subrange = pop @pieces;
5491 # If the name contained colons, the split broke it up.
5492 # Put it back together.
5493 $file = join( ':', @pieces );
5495 # If we're not in that file, switch over to it.
5496 if ( $file ne $filename ) {
5497 print $OUT "Switching to file '$file'.\n"
5498 unless $slave_editor;
5500 # Switch debugger's magic structures.
5501 *dbline = $main::{ '_<' . $file };
5504 } ## end if ($file ne $filename)
5506 # Subrange is 'start-stop'. If this is less than a window full,
5507 # swap it to 'start+', which will list a window from the start point.
5509 if ( eval($subrange) < -$window ) {
5510 $subrange =~ s/-.*/+/;
5513 # Call self recursively to list the range.
5515 cmd_l( 'l', $subrange );
5516 } ## end if ($subrange)
5520 print $OUT "Subroutine $subname not found.\n";
5522 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
5525 elsif ( $line !~ /\S/ ) {
5527 # Compute new range to list.
5528 $incr = $window - 1;
5529 $line = $start . '-' . ( $start + $incr );
5532 cmd_l( 'l', $line );
5535 # l [start]+number_of_lines
5536 elsif ( my ($new_start, $new_incr) = $line =~ /\A(\d*)\+(\d*)\z/ ) {
5538 # Don't reset start for 'l +nnn'.
5539 $start = $new_start if $new_start;
5541 # Increment for list. Use window size if not specified.
5542 # (Allows 'l +' to work.)
5544 $incr = $window - 1 unless $incr;
5546 # Create a line range we'll understand, and recurse to do it.
5547 $line = $start . '-' . ( $start + $incr );
5548 cmd_l( 'l', $line );
5549 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
5551 # l start-stop or l start,stop
5552 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) {
5554 # Determine end point; use end of file if not specified.
5555 my $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 );
5557 # Go on to the end, and then stop.
5558 $end = $max if $end > $max;
5560 # Determine start line.
5562 $i = $line if $i eq '.';
5566 # If we're running under a slave editor, force it to show the lines.
5567 if ($slave_editor) {
5568 print $OUT "\032\032$filename:$i:0\n";
5572 # We're doing it ourselves. We want to show the line and special
5574 # - the current line in execution
5575 # - whether a line is breakable or not
5576 # - whether a line has a break or not
5577 # - whether a line has an action or not
5579 for ( ; $i <= $end ; $i++ ) {
5581 # Check for breakpoints and actions.
5582 my ( $stop, $action );
5583 ( $stop, $action ) = split( /\0/, $dbline{$i} )
5586 # ==> if this is the current line in execution,
5587 # : if it's breakable.
5589 ( $i == $current_line and $filename eq $filename_ini )
5591 : ( $dbline[$i] + 0 ? ':' : ' ' );
5593 # Add break and action indicators.
5594 $arrow .= 'b' if $stop;
5595 $arrow .= 'a' if $action;
5598 print $OUT "$i$arrow\t", $dbline[$i];
5600 # Move on to the next line. Drop out on an interrupt.
5601 $i++, last if $signal;
5602 } ## end for (; $i <= $end ; $i++)
5604 # Line the prompt up; print a newline if the last line listed
5605 # didn't have a newline.
5606 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/;
5607 } ## end else [ if ($slave_editor)
5609 # Save the point we last listed to in case another relative 'l'
5610 # command is desired. Don't let it run off the end.
5612 $start = $max if $start > $max;
5613 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
5616 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5618 To list breakpoints, the command has to look determine where all of them are
5619 first. It starts a C<%had_breakpoints>, which tells us what all files have
5620 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5621 magic source and breakpoint data structures) to the file, and then look
5622 through C<%dbline> for lines with breakpoints and/or actions, listing them
5623 out. We look through C<%postponed> not-yet-compiled subroutines that have
5624 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5625 that have breakpoints.
5627 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5634 # If no argument, list everything. Pre-5.8.0 version always lists
5636 my $arg = shift || 'abw';
5637 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
5639 # See what is wanted.
5640 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0;
5641 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0;
5642 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0;
5644 # Breaks and actions are found together, so we look in the same place
5646 if ( $break_wanted or $action_wanted ) {
5648 # Look in all the files with breakpoints...
5649 for my $file ( keys %had_breakpoints ) {
5651 # Temporary switch to this file.
5652 local *dbline = $main::{ '_<' . $file };
5654 # Set up to look through the whole file.
5656 my $was; # Flag: did we print something
5659 # For each line in the file ...
5660 for my $i (1 .. $max) {
5662 # We've got something on this line.
5663 if ( defined $dbline{$i} ) {
5665 # Print the header if we haven't.
5666 print $OUT "$file:\n" unless $was++;
5669 print $OUT " $i:\t", $dbline[$i];
5671 # Pull out the condition and the action.
5672 my ( $stop, $action ) = split( /\0/, $dbline{$i} );
5674 # Print the break if there is one and it's wanted.
5675 print $OUT " break if (", $stop, ")\n"
5679 # Print the action if there is one and it's wanted.
5680 print $OUT " action: ", $action, "\n"
5684 # Quit if the user hit interrupt.
5686 } ## end if (defined $dbline{$i...
5687 } ## end for my $i (1 .. $max)
5688 } ## end for my $file (keys %had_breakpoints)
5689 } ## end if ($break_wanted or $action_wanted)
5691 # Look for breaks in not-yet-compiled subs:
5692 if ( %postponed and $break_wanted ) {
5693 print $OUT "Postponed breakpoints in subroutines:\n";
5695 for $subname ( keys %postponed ) {
5696 print $OUT " $subname\t$postponed{$subname}\n";
5699 } ## end if (%postponed and $break_wanted)
5701 # Find files that have not-yet-loaded breaks:
5702 my @have = map { # Combined keys
5703 keys %{ $postponed_file{$_} }
5704 } keys %postponed_file;
5706 # If there are any, list them.
5707 if ( @have and ( $break_wanted or $action_wanted ) ) {
5708 print $OUT "Postponed breakpoints in files:\n";
5709 for my $file ( keys %postponed_file ) {
5710 my $db = $postponed_file{$file};
5711 print $OUT " $file:\n";
5712 for my $line ( sort { $a <=> $b } keys %$db ) {
5713 print $OUT " $line:\n";
5714 my ( $stop, $action ) = split( /\0/, $$db{$line} );
5715 print $OUT " break if (", $stop, ")\n"
5718 print $OUT " action: ", $action, "\n"
5722 } ## end for $line (sort { $a <=>...
5724 } ## end for $file (keys %postponed_file)
5725 } ## end if (@have and ($break_wanted...
5726 if ( %break_on_load and $break_wanted ) {
5727 print {$OUT} "Breakpoints on load:\n";
5728 BREAK_ON_LOAD: for my $filename ( keys %break_on_load ) {
5729 print {$OUT} " $filename\n";
5730 last BREAK_ON_LOAD if $signal;
5732 } ## end if (%break_on_load and...
5733 if ($watch_wanted and ( $trace & 2 )) {
5734 print {$OUT} "Watch-expressions:\n" if @to_watch;
5735 TO_WATCH: for my $expr (@to_watch) {
5736 print {$OUT} " $expr\n";
5737 last TO_WATCH if $signal;
5742 =head3 C<cmd_M> - list modules (command)
5744 Just call C<list_modules>.
5754 =head3 C<cmd_o> - options (command)
5756 If this is just C<o> by itself, we list the current settings via
5757 C<dump_option>. If there's a nonblank value following it, we pass that on to
5758 C<parse_options> for processing.
5764 my $opt = shift || ''; # opt[=val]
5766 # Nonblank. Try to parse and process.
5767 if ( $opt =~ /^(\S.*)/ ) {
5771 # Blank. List the current option settings.
5779 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5781 Advises the user that the O command has been renamed.
5786 print $OUT "The old O command is now the o command.\n"; # hint
5787 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5788 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5791 =head3 C<cmd_v> - view window (command)
5793 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5794 move back a few lines to list the selected line in context. Uses C<cmd_l>
5795 to do the actual listing after figuring out the range of line to request.
5799 use vars qw($preview);
5805 # Extract the line to list around. (Astute readers will have noted that
5806 # this pattern will match whether or not a numeric line is specified,
5807 # which means that we'll always enter this loop (though a non-numeric
5808 # argument results in no action at all)).
5809 if ( $line =~ /^(\d*)$/ ) {
5811 # Total number of lines to list (a windowful).
5812 $incr = $window - 1;
5814 # Set the start to the argument given (if there was one).
5817 # Back up by the context amount.
5820 # Put together a linespec that cmd_l will like.
5821 $line = $start . '-' . ( $start + $incr );
5824 cmd_l( 'l', $line );
5825 } ## end if ($line =~ /^(\d*)$/)
5828 =head3 C<cmd_w> - add a watch expression (command)
5830 The 5.8 version of this command adds a watch expression if one is specified;
5831 it does nothing if entered with no operands.
5833 We extract the expression, save it, evaluate it in the user's context, and
5834 save the value. We'll re-evaluate it each time the debugger passes a line,
5835 and will stop (see the code at the top of the command loop) if the value
5836 of any of the expressions changes.
5840 sub _add_watch_expr {
5844 push @to_watch, $expr;
5846 # Parameterize DB::eval and call it to get the expression's value
5847 # in the user's context. This version can handle expressions which
5848 # return a list value.
5850 my ($val) = join( ' ', DB::eval() );
5851 $val = ( defined $val ) ? "'$val'" : 'undef';
5853 # Save the current value of the expression.
5854 push @old_watch, $val;
5856 # We are now watching expressions.
5865 # Null expression if no arguments.
5866 my $expr = shift || '';
5868 # If expression is not null ...
5869 if ( $expr =~ /\A\S/ ) {
5870 _add_watch_expr($expr);
5871 } ## end if ($expr =~ /^(\S.*)/)
5873 # You have to give one to get one.
5875 print $OUT "Adding a watch-expression requires an expression\n"; # hint
5881 =head3 C<cmd_W> - delete watch expressions (command)
5883 This command accepts either a watch expression to be removed from the list
5884 of watch expressions, or C<*> to delete them all.
5886 If C<*> is specified, we simply empty the watch expression list and the
5887 watch expression value list. We also turn off the bit that says we've got
5890 If an expression (or partial expression) is specified, we pattern-match
5891 through the expressions and remove the ones that match. We also discard
5892 the corresponding values. If no watch expressions are left, we turn off
5893 the I<watching expressions> bit.
5899 my $expr = shift || '';
5902 if ( $expr eq '*' ) {
5907 print $OUT "Deleting all watch expressions ...\n";
5910 @to_watch = @old_watch = ();
5913 # Delete one of them.
5914 elsif ( $expr =~ /^(\S.*)/ ) {
5916 # Where we are in the list.
5919 # For each expression ...
5920 foreach (@to_watch) {
5921 my $val = $to_watch[$i_cnt];
5923 # Does this one match the command argument?
5924 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
5925 # Yes. Turn it off, and its value too.
5926 splice( @to_watch, $i_cnt, 1 );
5927 splice( @old_watch, $i_cnt, 1 );
5930 } ## end foreach (@to_watch)
5932 # We don't bother to turn watching off because
5933 # a) we don't want to stop calling watchfunction() it it exists
5934 # b) foreach over a null list doesn't do anything anyway
5936 } ## end elsif ($expr =~ /^(\S.*)/)
5938 # No command arguments entered.
5941 "Deleting a watch-expression requires an expression, or '*' for all\n"
5946 ### END of the API section
5948 =head1 SUPPORT ROUTINES
5950 These are general support routines that are used in a number of places
5951 throughout the debugger.
5955 save() saves the user's versions of globals that would mess us up in C<@saved>,
5956 and installs the versions we like better.
5962 # Save eval failure, command failure, extended OS error, output field
5963 # separator, input record separator, output record separator and
5964 # the warning setting.
5965 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
5967 $, = ""; # output field separator is null string
5968 $/ = "\n"; # input record separator is newline
5969 $\ = ""; # output record separator is null string
5970 $^W = 0; # warnings are off
5973 =head2 C<print_lineinfo> - show where we are now
5975 print_lineinfo prints whatever it is that it is handed; it prints it to the
5976 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5977 us to feed line information to a slave editor without messing up the
5982 sub print_lineinfo {
5984 # Make the terminal sensible if we're not the primary debugger.
5985 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5989 } ## end sub print_lineinfo
5991 =head2 C<postponed_sub>
5993 Handles setting postponed breakpoints in subroutines once they're compiled.
5994 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5995 range for the subroutine, then mark the file as having a breakpoint,
5996 temporarily switch the C<*dbline> glob over to the source file, and then
5997 search the given range of lines to find a breakable line. If we find one,
5998 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
6002 # The following takes its argument via $evalarg to preserve current @_
6006 # Get the subroutine name.
6007 my $subname = shift;
6009 # If this is a 'break +<n> if <condition>' ...
6010 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
6012 # If there's no offset, use '+0'.
6013 my $offset = $1 || 0;
6015 # find_sub's value is 'fullpath-filename:start-stop'. It's
6016 # possible that the filename might have colons in it too.
6017 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
6020 # We got the start line. Add the offset '+<n>' from
6021 # $postponed{subname}.
6024 # Switch to the file this sub is in, temporarily.
6025 local *dbline = $main::{ '_<' . $file };
6027 # No warnings, please.
6028 local $^W = 0; # != 0 is magical below
6030 # This file's got a breakpoint in it.
6031 $had_breakpoints{$file} |= 1;
6033 # Last line in file.
6036 # Search forward until we hit a breakable line or get to
6037 # the end of the file.
6038 ++$i until $dbline[$i] != 0 or $i >= $max;
6040 # Copy the breakpoint in and delete it from %postponed.
6041 $dbline{$i} = delete $postponed{$subname};
6044 # find_sub didn't find the sub.
6047 print $OUT "Subroutine $subname not found.\n";
6050 } ## end if ($postponed{$subname...
6051 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
6053 #print $OUT "In postponed_sub for '$subname'.\n";
6054 } ## end sub postponed_sub
6058 Called after each required file is compiled, but before it is executed;
6059 also called if the name of a just-compiled subroutine is a key of
6060 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
6061 etc.) into the just-compiled code.
6063 If this is a C<require>'d file, the incoming parameter is the glob
6064 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
6066 If it's a subroutine, the incoming parameter is the subroutine name.
6072 # If there's a break, process it.
6073 if ($ImmediateStop) {
6075 # Right, we've stopped. Turn it off.
6078 # Enter the command loop when DB::DB gets called.
6082 # If this is a subroutine, let postponed_sub() deal with it.
6083 return postponed_sub(@_) unless ref \$_[0] eq 'GLOB';
6085 # Not a subroutine. Deal with the file.
6086 local *dbline = shift;
6087 my $filename = $dbline;
6088 $filename =~ s/^_<//;
6090 $signal = 1, print $OUT "'$filename' loaded...\n"
6091 if $break_on_load{$filename};
6092 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
6094 # Do we have any breakpoints to put in this file?
6095 return unless $postponed_file{$filename};
6097 # Yes. Mark this file as having breakpoints.
6098 $had_breakpoints{$filename} |= 1;
6100 # "Cannot be done: insufficient magic" - we can't just put the
6101 # breakpoints saved in %postponed_file into %dbline by assigning
6102 # the whole hash; we have to do it one item at a time for the
6103 # breakpoints to be set properly.
6104 #%dbline = %{$postponed_file{$filename}};
6106 # Set the breakpoints, one at a time.
6109 for $key ( keys %{ $postponed_file{$filename} } ) {
6111 # Stash the saved breakpoint into the current file's magic line array.
6112 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
6115 # This file's been compiled; discard the stored breakpoints.
6116 delete $postponed_file{$filename};
6118 } ## end sub postponed
6122 C<dumpit> is the debugger's wrapper around dumpvar.pl.
6124 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
6125 a reference to a variable (the thing to be dumped) as its input.
6127 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
6128 the currently-selected filehandle, thank you very much). The current
6129 values of the package globals C<$single> and C<$trace> are backed up in
6130 lexicals, and they are turned off (this keeps the debugger from trying
6131 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
6132 preserve its current value and it is set to zero to prevent entry/exit
6133 messages from printing, and C<$doret> is localized as well and set to -2 to
6134 prevent return values from being shown.
6136 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
6137 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
6138 installed version in C<@INC>, yours will be used instead. Possible security
6141 It then checks to see if the subroutine C<main::dumpValue> is now defined
6142 it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
6143 localizes the globals necessary for things to be sane when C<main::dumpValue()>
6144 is called, and picks up the variable to be dumped from the parameter list.
6146 It checks the package global C<%options> to see if there's a C<dumpDepth>
6147 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
6148 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
6149 structure: -1 means dump everything.
6151 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
6154 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
6155 and we then return to the caller.
6161 # Save the current output filehandle and switch to the one
6162 # passed in as the first parameter.
6163 my $savout = select(shift);
6165 # Save current settings of $single and $trace, and then turn them off.
6166 my $osingle = $single;
6167 my $otrace = $trace;
6168 $single = $trace = 0;
6170 # XXX Okay, what do $frame and $doret do, again?
6174 # Load dumpvar.pl unless we've already got the sub we need from it.
6175 unless ( defined &main::dumpValue ) {
6176 do 'dumpvar.pl' or die $@;
6179 # If the load succeeded (or we already had dumpvalue()), go ahead
6181 if ( defined &main::dumpValue ) {
6186 my $maxdepth = shift || $option{dumpDepth};
6187 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
6188 main::dumpValue( $v, $maxdepth );
6189 } ## end if (defined &main::dumpValue)
6191 # Oops, couldn't load dumpvar.pl.
6194 print $OUT "dumpvar.pl not available.\n";
6197 # Reset $single and $trace to their old values.
6201 # Restore the old filehandle.
6205 =head2 C<print_trace>
6207 C<print_trace>'s job is to print a stack trace. It does this via the
6208 C<dump_trace> routine, which actually does all the ferreting-out of the
6209 stack trace data. C<print_trace> takes care of formatting it nicely and
6210 printing it to the proper filehandle.
6218 The filehandle to print to.
6222 How many frames to skip before starting trace.
6226 How many frames to print.
6230 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
6234 The original comment below seems to be noting that the traceback may not be
6235 correct if this routine is called in a tied method.
6239 # Tied method do not create a context, so may get wrong message:
6245 # If this is going to a slave editor, but we're not the primary
6246 # debugger, reset it first.
6248 if $fh eq $LINEINFO # slave editor
6249 and $LINEINFO eq $OUT # normal output
6250 and $term_pid != $$; # not the primary
6252 # Collect the actual trace information to be formatted.
6253 # This is an array of hashes of subroutine call info.
6254 my @sub = dump_trace( $_[0] + 1, $_[1] );
6256 # Grab the "short report" flag from @_.
6257 my $short = $_[2]; # Print short report, next one for sub name
6259 # Run through the traceback info, format it, and print it.
6261 for my $i (0 .. $#sub) {
6263 # Drop out if the user has lost interest and hit control-C.
6266 # Set the separator so arrys print nice.
6269 # Grab and stringify the arguments if they are there.
6271 defined $sub[$i]{args}
6272 ? "(@{ $sub[$i]{args} })"
6275 # Shorten them up if $maxtrace says they're too long.
6276 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
6277 if length $args > $maxtrace;
6279 # Get the file name.
6280 my $file = $sub[$i]{file};
6282 # Put in a filename header if short is off.
6283 $file = $file eq '-e' ? $file : "file '$file'" unless $short;
6285 # Get the actual sub's name, and shorten to $maxtrace's requirement.
6286 $s = $sub[$i]{'sub'};
6287 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
6289 # Short report uses trimmed file and sub names.
6291 my $sub = @_ >= 4 ? $_[3] : $s;
6292 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
6293 } ## end if ($short)
6295 # Non-short report includes full names.
6297 print $fh "$sub[$i]{context} = $s$args"
6298 . " called from $file"
6299 . " line $sub[$i]{line}\n";
6301 } ## end for my $i (0 .. $#sub)
6302 } ## end sub print_trace
6304 =head2 dump_trace(skip[,count])
6306 Actually collect the traceback information available via C<caller()>. It does
6307 some filtering and cleanup of the data, but mostly it just collects it to
6308 make C<print_trace()>'s job easier.
6310 C<skip> defines the number of stack frames to be skipped, working backwards
6311 from the most current. C<count> determines the total number of frames to
6312 be returned; all of them (well, the first 10^9) are returned if C<count>
6315 This routine returns a list of hashes, from most-recent to least-recent
6316 stack frame. Each has the following keys and values:
6320 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
6322 =item * C<sub> - subroutine name, or C<eval> information
6324 =item * C<args> - undef, or a reference to an array of arguments
6326 =item * C<file> - the file in which this item was defined (if any)
6328 =item * C<line> - the line on which it was defined
6336 # How many levels to skip.
6339 # How many levels to show. (1e9 is a cheap way of saying "all of them";
6340 # it's unlikely that we'll have more than a billion stack frames. If you
6341 # do, you've got an awfully big machine...)
6342 my $count = shift || 1e9;
6344 # We increment skip because caller(1) is the first level *back* from
6345 # the current one. Add $skip to the count of frames so we have a
6346 # simple stop criterion, counting from $skip to $count+$skip.
6350 # These variables are used to capture output from caller();
6351 my ( $p, $file, $line, $sub, $h, $context );
6353 my ( $e, $r, @a, @sub, $args );
6355 # XXX Okay... why'd we do that?
6356 my $nothard = not $frame & 8;
6359 # Do not want to trace this.
6360 my $otrace = $trace;
6363 # Start out at the skip count.
6364 # If we haven't reached the number of frames requested, and caller() is
6365 # still returning something, stay in the loop. (If we pass the requested
6366 # number of stack frames, or we run out - caller() returns nothing - we
6368 # Up the stack frame index to go back one more level each time.
6372 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
6377 # Go through the arguments and save them for later.
6379 for my $arg (@args) {
6381 if ( not defined $arg ) { # undefined parameter
6385 elsif ( $nothard and tied $arg ) { # tied parameter
6388 elsif ( $nothard and $type = ref $arg ) { # reference
6389 push @a, "ref($type)";
6391 else { # can be stringified
6393 "$arg"; # Safe to stringify now - should not call f().
6395 # Backslash any single-quotes or backslashes.
6398 # Single-quote it unless it's a number or a colon-separated
6401 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
6403 # Turn high-bit characters into meta-whatever.
6404 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
6406 # Turn control characters into ^-whatever.
6407 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
6410 } ## end else [ if (not defined $arg)
6411 } ## end for $arg (@args)
6413 # If context is true, this is array (@)context.
6414 # If context is false, this is scalar ($) context.
6415 # If neither, context isn't defined. (This is apparently a 'can't
6417 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
6419 # if the sub has args ($h true), make an anonymous array of the
6421 $args = $h ? [@a] : undef;
6423 # remove trailing newline-whitespace-semicolon-end of line sequence
6424 # from the eval text, if any.
6425 $e =~ s/\n\s*\;\s*\Z// if $e;
6427 # Escape backslashed single-quotes again if necessary.
6428 $e =~ s/([\\\'])/\\$1/g if $e;
6430 # if the require flag is true, the eval text is from a require.
6432 $sub = "require '$e'";
6435 # if it's false, the eval text is really from an eval.
6436 elsif ( defined $r ) {
6440 # If the sub is '(eval)', this is a block eval, meaning we don't
6441 # know what the eval'ed text actually was.
6442 elsif ( $sub eq '(eval)' ) {
6443 $sub = "eval {...}";
6446 # Stick the collected information into @sub as an anonymous hash.
6450 context => $context,
6458 # Stop processing frames if the user hit control-C.
6460 } ## end for ($i = $skip ; $i < ...
6462 # Restore the trace value again.
6465 } ## end sub dump_trace
6469 C<action()> takes input provided as the argument to an add-action command,
6470 either pre- or post-, and makes sure it's a complete command. It doesn't do
6471 any fancy parsing; it just keeps reading input until it gets a string
6472 without a trailing backslash.
6479 while ( $action =~ s/\\$// ) {
6481 # We have a backslash on the end. Read more.
6483 } ## end while ($action =~ s/\\$//)
6485 # Return the assembled action.
6491 This routine mostly just packages up a regular expression to be used
6492 to check that the thing it's being matched against has properly-matched
6495 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
6496 speeds things up by only creating the qr//'ed expression once; if it's
6497 already defined, we don't try to define it again. A speed hack.
6501 use vars qw($balanced_brace_re);
6505 # I hate using globals!
6506 $balanced_brace_re ||= qr{
6509 (?> [^{}] + ) # Non-parens without backtracking
6511 (??{ $balanced_brace_re }) # Group with matching parens
6515 return $_[0] !~ m/$balanced_brace_re/;
6516 } ## end sub unbalanced
6520 C<gets()> is a primitive (very primitive) routine to read continuations.
6521 It was devised for reading continuations for actions.
6522 it just reads more input with C<readline()> and returns it.
6527 return DB::readline("cont: ");
6530 =head2 C<_db_system()> - handle calls to<system()> without messing up the debugger
6532 The C<system()> function assumes that it can just go ahead and use STDIN and
6533 STDOUT, but under the debugger, we want it to use the debugger's input and
6536 C<_db_system()> socks away the program's STDIN and STDOUT, and then substitutes
6537 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
6538 and then puts everything back again.
6544 # We save, change, then restore STDIN and STDOUT to avoid fork() since
6545 # some non-Unix systems can do system() but have problems with fork().
6546 open( SAVEIN, "<&STDIN" ) || db_warn("Can't save STDIN");
6547 open( SAVEOUT, ">&STDOUT" ) || db_warn("Can't save STDOUT");
6548 open( STDIN, "<&IN" ) || db_warn("Can't redirect STDIN");
6549 open( STDOUT, ">&OUT" ) || db_warn("Can't redirect STDOUT");
6551 # XXX: using csh or tcsh destroys sigint retvals!
6553 open( STDIN, "<&SAVEIN" ) || db_warn("Can't restore STDIN");
6554 open( STDOUT, ">&SAVEOUT" ) || db_warn("Can't restore STDOUT");
6558 # most of the $? crud was coping with broken cshisms
6560 db_warn( "(Command exited ", ( $? >> 8 ), ")\n" );
6564 "(Command died of SIG#",
6566 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6575 *system = \&_db_system;
6577 =head1 TTY MANAGEMENT
6579 The subs here do some of the terminal management for multiple debuggers.
6583 Top-level function called when we want to set up a new terminal for use
6586 If the C<noTTY> debugger option was set, we'll either use the terminal
6587 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6588 to find one. If we're a forked debugger, we call C<resetterm> to try to
6589 get a whole new terminal if we can.
6591 In either case, we set up the terminal next. If the C<ReadLine> option was
6592 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6593 the appropriate attributes. We then
6597 use vars qw($ornaments);
6598 use vars qw($rl_attribs);
6602 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6605 require Term::ReadLine;
6607 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6610 my ( $i, $o ) = split $tty, /,/;
6611 $o = $i unless defined $o;
6612 open( IN, "<$i" ) or die "Cannot open TTY '$i' for read: $!";
6613 open( OUT, ">$o" ) or die "Cannot open TTY '$o' for write: $!";
6619 # We don't have a TTY - try to find one via Term::Rendezvous.
6621 require Term::Rendezvous;
6623 # See if we have anything to pass to Term::Rendezvous.
6624 # Use $HOME/.perldbtty$$ if not.
6625 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6627 # Rendezvous and get the filehandles.
6628 my $term_rv = Term::Rendezvous->new( $rv );
6630 $OUT = $term_rv->OUT;
6631 } ## end else [ if ($tty)
6632 } ## end if ($notty)
6634 # We're a daughter debugger. Try to fork off another TTY.
6635 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6639 # If we shouldn't use Term::ReadLine, don't.
6641 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6644 # We're using Term::ReadLine. Get all the attributes for this terminal.
6646 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6648 $rl_attribs = $term->Attribs;
6649 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6650 if defined $rl_attribs->{basic_word_break_characters}
6651 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6652 $rl_attribs->{special_prefixes} = '$@&%';
6653 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6654 $rl_attribs->{completion_function} = \&db_complete;
6655 } ## end else [ if (!$rl)
6657 # Set up the LINEINFO filehandle.
6658 $LINEINFO = $OUT unless defined $LINEINFO;
6659 $lineinfo = $console unless defined $lineinfo;
6665 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6666 $term->SetHistory(@hist);
6669 # XXX Ornaments are turned on unconditionally, which is not
6670 # always a good thing.
6671 ornaments($ornaments) if defined $ornaments;
6673 } ## end sub setterm
6676 $histfile //= option_val("HistFile", undef);
6677 return unless defined $histfile;
6678 open my $fh, "<", $histfile or return;
6689 return unless defined $histfile;
6690 eval { require File::Path } or return;
6691 eval { require File::Basename } or return;
6692 File::Path::mkpath(File::Basename::dirname($histfile));
6693 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6694 $histsize //= option_val("HistSize",100);
6695 my @copy = grep { $_ ne '?' } @hist;
6696 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6697 for ($start .. $#copy) {
6698 print $fh "$copy[$_]\n";
6700 close $fh or die "Could not write '$histfile': $!";
6703 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6705 When the process being debugged forks, or the process invokes a command
6706 via C<system()> which starts a new debugger, we need to be able to get a new
6707 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6708 fight over the terminal, and you can never quite be sure who's going to get the
6709 input you're typing.
6711 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6712 is tasked with doing all the necessary operating system mojo to get a new
6713 TTY (and probably another window) and to direct the new debugger to read and
6716 The debugger provides C<get_fork_TTY> functions which work for TCP
6717 socket servers, X11, OS/2, and Mac OS X. Other systems are not
6718 supported. You are encouraged to write C<get_fork_TTY> functions which
6719 work for I<your> platform and contribute them.
6721 =head3 C<socket_get_fork_TTY>
6725 sub connect_remoteport {
6728 my $socket = IO::Socket::INET->new(
6730 PeerAddr => $remoteport,
6734 die "Unable to connect to remote host: $remoteport\n";
6739 sub socket_get_fork_TTY {
6740 $tty = $LINEINFO = $IN = $OUT = connect_remoteport();
6742 # Do I need to worry about setting $term?
6744 reset_IN_OUT( $IN, $OUT );
6748 =head3 C<xterm_get_fork_TTY>
6750 This function provides the C<get_fork_TTY> function for X11. If a
6751 program running under the debugger forks, a new <xterm> window is opened and
6752 the subsidiary debugger is directed there.
6754 The C<open()> call is of particular note here. We have the new C<xterm>
6755 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6756 command (which prints the device name of the TTY we'll want to use for input
6757 and output to STDOUT, then C<sleep> for a very long time, routing this output
6758 to file number 3. This way we can simply read from the <XT> filehandle (which
6759 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6761 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6766 sub xterm_get_fork_TTY {
6767 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6769 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6772 # Get the output from 'tty' and clean it up a little.
6776 $pidprompt = ''; # Shown anyway in titlebar
6778 # We need $term defined or we can not switch to the newly created xterm
6779 if ($tty ne '' && !defined $term) {
6780 require Term::ReadLine;
6782 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6785 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6788 # There's our new TTY.
6790 } ## end sub xterm_get_fork_TTY
6792 =head3 C<os2_get_fork_TTY>
6794 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6798 # This example function resets $IN, $OUT itself
6800 sub os2_get_fork_TTY { # A simplification of the following (and works without):
6802 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6803 my %opt = ( title => "Daughter Perl debugger $pids $name",
6804 ($rl ? (read_by_key => 1) : ()) );
6805 require OS2::Process;
6806 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
6808 $pidprompt = ''; # Shown anyway in titlebar
6809 reset_IN_OUT($in, $out);
6811 return ''; # Indicate that reset_IN_OUT is called
6812 } ## end sub os2_get_fork_TTY
6814 =head3 C<macosx_get_fork_TTY>
6816 The Mac OS X version uses AppleScript to tell Terminal.app to create
6821 # Notes about Terminal.app's AppleScript support,
6822 # (aka things that might break in future OS versions).
6824 # The "do script" command doesn't return a reference to the new window
6825 # it creates, but since it appears frontmost and windows are enumerated
6826 # front to back, we can use "first window" === "window 1".
6828 # Since "do script" is implemented by supplying the argument (plus a
6829 # return character) as terminal input, there's a potential race condition
6830 # where the debugger could beat the shell to reading the command.
6831 # To prevent this, we wait for the screen to clear before proceeding.
6834 # There's no direct accessor for the tty device name, so we fiddle
6835 # with the window title options until it says what we want.
6838 # There _is_ a direct accessor for the tty device name, _and_ there's
6839 # a new possible component of the window title (the name of the settings
6840 # set). A separate version is needed.
6842 my @script_versions=
6844 ([237, <<'__LEOPARD__'],
6845 tell application "Terminal"
6846 do script "clear;exec sleep 100000"
6847 tell first tab of first window
6849 set custom title to "forked perl debugger"
6850 set title displays custom title to true
6851 repeat while (length of first paragraph of (get contents)) > 0
6859 [100, <<'__JAGUAR_TIGER__'],
6860 tell application "Terminal"
6861 do script "clear;exec sleep 100000"
6863 set title displays shell path to false
6864 set title displays window size to false
6865 set title displays file name to false
6866 set title displays device name to true
6867 set title displays custom title to true
6868 set custom title to ""
6869 copy "/dev/" & name to thetty
6870 set custom title to "forked perl debugger"
6871 repeat while (length of first paragraph of (get contents)) > 0
6881 sub macosx_get_fork_TTY
6883 my($version,$script,$pipe,$tty);
6885 return unless $version=$ENV{TERM_PROGRAM_VERSION};
6886 foreach my $entry (@script_versions) {
6887 if ($version>=$entry->[0]) {
6888 $script=$entry->[1];
6892 return unless defined($script);
6893 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
6894 $tty=readline($pipe);
6896 return unless defined($tty) && $tty =~ m(^/dev/);
6901 =head2 C<create_IN_OUT($flags)>
6903 Create a new pair of filehandles, pointing to a new TTY. If impossible,
6904 try to diagnose why.
6910 =item * 1 - Don't know how to create a new TTY.
6912 =item * 2 - Debugger has forked, but we can't get a new TTY.
6914 =item * 4 - standard debugger startup is happening.
6920 use vars qw($fork_TTY);
6922 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
6924 # If we know how to get a new TTY, do it! $in will have
6925 # the TTY name if get_fork_TTY works.
6926 my $in = get_fork_TTY(@_) if defined &get_fork_TTY;
6928 # It used to be that
6929 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
6931 if ( not defined $in ) {
6934 # We don't know how.
6935 print_help(<<EOP) if $why == 1;
6936 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6940 print_help(<<EOP) if $why == 2;
6941 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6942 This may be an asynchronous session, so the parent debugger may be active.
6945 # Note that both debuggers are fighting over the same input.
6946 print_help(<<EOP) if $why != 4;
6947 Since two debuggers fight for the same TTY, input is severely entangled.
6951 I know how to switch the output to a different window in xterms, OS/2
6952 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
6953 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
6954 B<DB::get_fork_TTY()> returning this.
6956 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6957 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6960 } ## end if (not defined $in)
6961 elsif ( $in ne '' ) {
6965 $console = ''; # Indicate no need to open-from-the-console
6968 } ## end sub create_IN_OUT
6972 Handles rejiggering the prompt when we've forked off a new debugger.
6974 If the new debugger happened because of a C<system()> that invoked a
6975 program under the debugger, the arrow between the old pid and the new
6976 in the prompt has I<two> dashes instead of one.
6978 We take the current list of pids and add this one to the end. If there
6979 isn't any list yet, we make one up out of the initial pid associated with
6980 the terminal and our new pid, sticking an arrow (either one-dashed or
6981 two dashed) in between them.
6983 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6984 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6989 sub resetterm { # We forked, so we need a different TTY
6991 # Needs to be passed to create_IN_OUT() as well.
6994 # resetterm(2): got in here because of a system() starting a debugger.
6995 # resetterm(1): just forked.
6996 my $systemed = $in > 1 ? '-' : '';
6998 # If there's already a list of pids, add this to the end.
7000 $pids =~ s/\]/$systemed->$$]/;
7003 # No pid list. Time to make one.
7005 $pids = "[$term_pid->$$]";
7008 # The prompt we're going to be using for this debugger.
7011 # We now 0wnz this terminal.
7014 # Just return if we're not supposed to try to create a new TTY.
7015 return unless $CreateTTY & $in;
7017 # Try to create a new IN/OUT pair.
7019 } ## end sub resetterm
7023 First, we handle stuff in the typeahead buffer. If there is any, we shift off
7024 the next line, print a message saying we got it, add it to the terminal
7025 history (if possible), and return it.
7027 If there's nothing in the typeahead buffer, check the command filehandle stack.
7028 If there are any filehandles there, read from the last one, and return the line
7029 if we got one. If not, we pop the filehandle off and close it, and try the
7030 next one up the stack.
7032 If we've emptied the filehandle stack, we check to see if we've got a socket
7033 open, and we read that and return it if we do. If we don't, we just call the
7034 core C<readline()> and return its value.
7040 # Localize to prevent it from being smashed in the program being debugged.
7043 # If there are stacked filehandles to read from ...
7044 # (Handle it before the typeahead, because we may call source/etc. from
7048 # Read from the last one in the stack.
7049 my $line = CORE::readline( $cmdfhs[-1] );
7051 # If we got a line ...
7053 ? ( print $OUT ">> $line" and return $line ) # Echo and return
7054 : close pop @cmdfhs; # Pop and close
7055 } ## end while (@cmdfhs)
7057 # Pull a line out of the typeahead if there's stuff there.
7060 # How many lines left.
7061 my $left = @typeahead;
7063 # Get the next line.
7064 my $got = shift @typeahead;
7066 # Print a message saying we got input from the typeahead.
7068 print $OUT "auto(-$left)", shift, $got, "\n";
7070 # Add it to the terminal history (if possible).
7071 $term->AddHistory($got)
7073 and defined $term->Features->{addHistory};
7075 } ## end if (@typeahead)
7077 # We really need to read some input. Turn off entry/exit trace and
7078 # return value printing.
7082 # Nothing on the filehandle stack. Socket?
7083 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
7085 # Send anything we have to send.
7086 $OUT->write( join( '', @_ ) );
7088 # Receive anything there is to receive.
7093 while ($first_time or (length($buf) && ($stuff .= $buf) !~ /\n/))
7096 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
7097 # XXX Don't know. You tell me.
7102 } ## end if (ref $OUT and UNIVERSAL::isa...
7104 # No socket. Just read from the terminal.
7106 return $term->readline(@_);
7108 } ## end sub readline
7110 =head1 OPTIONS SUPPORT ROUTINES
7112 These routines handle listing and setting option values.
7114 =head2 C<dump_option> - list the current value of an option setting
7116 This routine uses C<option_val> to look up the value for an option.
7117 It cleans up escaped single-quotes and then displays the option and
7123 my ( $opt, $val ) = @_;
7124 $val = option_val( $opt, 'N/A' );
7125 $val =~ s/([\\\'])/\\$1/g;
7126 printf $OUT "%20s = '%s'\n", $opt, $val;
7127 } ## end sub dump_option
7129 sub options2remember {
7130 foreach my $k (@RememberOnROptions) {
7131 $option{$k} = option_val( $k, 'N/A' );
7136 =head2 C<option_val> - find the current value of an option
7138 This can't just be a simple hash lookup because of the indirect way that
7139 the option values are stored. Some are retrieved by calling a subroutine,
7140 some are just variables.
7142 You must supply a default value to be used in case the option isn't set.
7147 my ( $opt, $default ) = @_;
7150 # Does this option exist, and is it a variable?
7151 # If so, retrieve the value via the value in %optionVars.
7152 if ( defined $optionVars{$opt}
7153 and defined ${ $optionVars{$opt} } )
7155 $val = ${ $optionVars{$opt} };
7158 # Does this option exist, and it's a subroutine?
7159 # If so, call the subroutine via the ref in %optionAction
7160 # and capture the value.
7161 elsif ( defined $optionAction{$opt}
7162 and defined &{ $optionAction{$opt} } )
7164 $val = &{ $optionAction{$opt} }();
7167 # If there's an action or variable for the supplied option,
7168 # but no value was set, use the default.
7169 elsif (defined $optionAction{$opt} and not defined $option{$opt}
7170 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
7175 # Otherwise, do the simple hash lookup.
7177 $val = $option{$opt};
7180 # If the value isn't defined, use the default.
7181 # Then return whatever the value is.
7182 $val = $default unless defined $val;
7184 } ## end sub option_val
7186 =head2 C<parse_options>
7188 Handles the parsing and execution of option setting/displaying commands.
7190 An option entered by itself is assumed to be I<set me to 1> (the default value)
7191 if the option is a boolean one. If not, the user is prompted to enter a valid
7192 value or to query the current value (via C<option? >).
7194 If C<option=value> is entered, we try to extract a quoted string from the
7195 value (if it is quoted). If it's not, we just use the whole value as-is.
7197 We load any modules required to service this option, and then we set it: if
7198 it just gets stuck in a variable, we do that; if there's a subroutine to
7199 handle setting the option, we call that.
7201 Finally, if we're running in interactive mode, we display the effect of the
7202 user's command back to the terminal, skipping this if we're setting things
7203 during initialization.
7213 # These options need a value. Don't allow them to be clobbered by accident.
7214 my %opt_needs_val = map { ( $_ => 1 ) } qw{
7215 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
7216 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
7219 while (length($s)) {
7222 # Clean off excess leading whitespace.
7223 $s =~ s/^\s+// && next;
7225 # Options are always all word characters, followed by a non-word
7227 if ($s !~ s/^(\w+)(\W?)//) {
7228 print {$OUT} "Invalid option '$s'\n";
7231 my ( $opt, $sep ) = ( $1, $2 );
7233 # Make sure that such an option exists.
7234 my $matches = ( grep { /^\Q$opt/ && ( $option = $_ ) } @options )
7235 || ( grep { /^\Q$opt/i && ( $option = $_ ) } @options );
7238 print {$OUT} "Unknown option '$opt'\n";
7242 print {$OUT} "Ambiguous option '$opt'\n";
7247 # '?' as separator means query, but must have whitespace after it.
7248 if ( "?" eq $sep ) {
7250 print {$OUT} "Option query '$opt?' followed by non-space '$s'\n" ;
7255 #&dump_option($opt);
7256 } ## end if ("?" eq $sep)
7258 # Separator is whitespace (or just a carriage return).
7259 # They're going for a default, which we assume is 1.
7260 elsif ( $sep !~ /\S/ ) {
7262 $val = "1"; # this is an evil default; make 'em set it!
7265 # Separator is =. Trying to set a value.
7266 elsif ( $sep eq "=" ) {
7268 # If quoted, extract a quoted string.
7269 if ($s =~ s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
7271 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
7274 # Not quoted. Use the whole thing. Warn about 'option='.
7278 print OUT qq(Option better cleared using $opt=""\n)
7280 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
7282 } ## end elsif ($sep eq "=")
7284 # "Quoted" with [], <>, or {}.
7285 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
7287 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
7288 $s =~ s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
7289 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last;
7290 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
7291 } ## end else [ if ("?" eq $sep)
7293 # Exclude non-booleans from getting set to 1 by default.
7294 if ( $opt_needs_val{$option} && $val_defaulted ) {
7295 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
7297 "Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n";
7299 } ## end if ($opt_needs_val{$option...
7301 # Save the option value.
7302 $option{$option} = $val if defined $val;
7304 # Load any module that this option requires.
7305 if ( defined($optionRequire{$option}) && defined($val) ) {
7309 require '$optionRequire{$option}';
7311 } || die $@ # XXX: shouldn't happen
7315 # Stick it in the proper variable if it goes in a variable.
7316 if (defined($optionVars{$option}) && defined($val)) {
7317 ${ $optionVars{$option} } = $val;
7320 # Call the appropriate sub if it gets set via sub.
7321 if (defined($optionAction{$option})
7322 && defined (&{ $optionAction{$option} })
7325 &{ $optionAction{$option} }($val);
7328 # Not initialization - echo the value we set it to.
7329 dump_option($option) if ($OUT ne \*STDERR);
7330 } ## end while (length)
7331 } ## end sub parse_options
7333 =head1 RESTART SUPPORT
7335 These routines are used to store (and restore) lists of items in environment
7336 variables during a restart.
7340 Set_list packages up items to be stored in a set of environment variables
7341 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
7342 the values). Values outside the standard ASCII charset are stored by encoding
7343 then as hexadecimal values.
7348 my ( $stem, @list ) = @_;
7351 # VAR_n: how many we have. Scalar assignment gets the number of items.
7352 $ENV{"${stem}_n"} = @list;
7354 # Grab each item in the list, escape the backslashes, encode the non-ASCII
7355 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
7356 for my $i ( 0 .. $#list ) {
7358 $val =~ s/\\/\\\\/g;
7359 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
7360 $ENV{"${stem}_$i"} = $val;
7361 } ## end for $i (0 .. $#list)
7362 } ## end sub set_list
7366 Reverse the set_list operation: grab VAR_n to see how many we should be getting
7367 back, and then pull VAR_0, VAR_1. etc. back out.
7374 my $n = delete $ENV{"${stem}_n"};
7376 for my $i ( 0 .. $n - 1 ) {
7377 $val = delete $ENV{"${stem}_$i"};
7378 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
7382 } ## end sub get_list
7384 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
7388 The C<catch()> subroutine is the essence of fast and low-impact. We simply
7389 set an already-existing global scalar variable to a constant value. This
7390 avoids allocating any memory possibly in the middle of something that will
7391 get all confused if we do, particularly under I<unsafe signals>.
7397 return; # Put nothing on the stack - malloc/free land!
7402 C<warn> emits a warning, by joining together its arguments and printing
7403 them, with couple of fillips.
7405 If the composited message I<doesn't> end with a newline, we automatically
7406 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
7407 to be set to the filehandle to be used to output warnings; it makes no
7408 assumptions about what filehandles are available.
7413 my ($msg) = join( "", @_ );
7414 $msg .= ": $!\n" unless $msg =~ /\n$/;
7421 =head1 INITIALIZATION TTY SUPPORT
7423 =head2 C<reset_IN_OUT>
7425 This routine handles restoring the debugger's input and output filehandles
7426 after we've tried and failed to move them elsewhere. In addition, it assigns
7427 the debugger's output filehandle to $LINEINFO if it was already open there.
7432 my $switch_li = $LINEINFO eq $OUT;
7434 # If there's a term and it's able to get a new tty, try to get one.
7435 if ( $term and $term->Features->{newTTY} ) {
7436 ( $IN, $OUT ) = ( shift, shift );
7437 $term->newTTY( $IN, $OUT );
7440 # This term can't get a new tty now. Better luck later.
7442 _db_warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n");
7445 # Set the filehndles up as they were.
7447 ( $IN, $OUT ) = ( shift, shift );
7450 # Unbuffer the output filehandle.
7453 # Point LINEINFO to the same output filehandle if it was there before.
7454 $LINEINFO = $OUT if $switch_li;
7455 } ## end sub reset_IN_OUT
7457 =head1 OPTION SUPPORT ROUTINES
7459 The following routines are used to process some of the more complicated
7464 Sets the input and output filehandles to the specified files or pipes.
7465 If the terminal supports switching, we go ahead and do it. If not, and
7466 there's already a terminal in place, we save the information to take effect
7469 If there's no terminal yet (for instance, during debugger initialization),
7470 we go ahead and set C<$console> and C<$tty> to the file indicated.
7476 if ( @_ and $term and $term->Features->{newTTY} ) {
7478 # This terminal supports switching to a new TTY.
7479 # Can be a list of two files, or on string containing both names,
7481 # XXX Should this perhaps be an assignment from @_?
7482 my ( $in, $out ) = shift;
7485 # Split list apart if supplied.
7486 ( $in, $out ) = split /,/, $in, 2;
7490 # Use the same file for both input and output.
7494 # Open file onto the debugger's filehandles, if you can.
7495 open IN, $in or die "cannot open '$in' for read: $!";
7496 open OUT, ">$out" or die "cannot open '$out' for write: $!";
7498 # Swap to the new filehandles.
7499 reset_IN_OUT( \*IN, \*OUT );
7501 # Save the setting for later.
7503 } ## end if (@_ and $term and $term...
7505 # Terminal doesn't support new TTY, or doesn't support readline.
7506 # Can't do it now, try restarting.
7508 _db_warn("Too late to set TTY, enabled on next 'R'!\n");
7511 # Useful if done through PERLDB_OPTS:
7512 $console = $tty = shift if @_;
7514 # Return whatever the TTY is.
7520 Sets the C<$notty> global, controlling whether or not the debugger tries to
7521 get a terminal to read from. If called after a terminal is already in place,
7522 we save the value to use it if we're restarted.
7528 _db_warn("Too late to set noTTY, enabled on next 'R'!\n") if @_;
7530 $notty = shift if @_;
7536 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
7537 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
7538 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
7539 the value in case a restart is done so we can change it then.
7545 _db_warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_;
7549 } ## end sub ReadLine
7551 =head2 C<RemotePort>
7553 Sets the port that the debugger will try to connect to when starting up.
7554 If the terminal's already been set up, we can't do it, but we remember the
7555 setting in case the user does a restart.
7561 _db_warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
7563 $remoteport = shift if @_;
7565 } ## end sub RemotePort
7569 Checks with the terminal to see if C<Tk> is running, and returns true or
7570 false. Returns false if the current terminal doesn't support C<readline>.
7575 if ( ${ $term->Features }{tkRunning} ) {
7576 return $term->tkRunning(@_);
7580 print $OUT "tkRunning not supported by current ReadLine package.\n";
7583 } ## end sub tkRunning
7587 Sets nonstop mode. If a terminal's already been set up, it's too late; the
7588 debugger remembers the setting in case you restart, though.
7594 _db_warn("Too late to set up NonStop mode, enabled on next 'R'!\n")
7597 $runnonstop = shift if @_;
7599 } ## end sub NonStop
7603 _db_warn("Some flag changes could not take effect until next 'R'!\n")
7606 $^P = parse_DollarCaretP_flags(shift) if @_;
7607 expand_DollarCaretP_flags($^P);
7612 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
7620 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7627 Sets the shell escape command, and generates a printable copy to be used
7634 # If we got an argument, meta-quote it, and add '\b' if it
7635 # ends in a word character.
7637 $sh = quotemeta shift;
7638 $sh .= "\\b" if $sh =~ /\w$/;
7641 # Generate the printable version for the help:
7642 $psh = $sh; # copy it
7643 $psh =~ s/\\b$//; # Take off trailing \b if any
7644 $psh =~ s/\\(.)/$1/g; # De-escape
7645 $psh; # return the printable version
7646 } ## end sub shellBang
7650 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7651 was passed as the argument. (This means you can't override the terminal's
7657 if ( defined $term ) {
7659 # We don't want to show warning backtraces, but we do want die() ones.
7660 local ( $warnLevel, $dieLevel ) = ( 0, 1 );
7662 # No ornaments if the terminal doesn't support them.
7663 return '' unless $term->Features->{ornaments};
7664 eval { $term->ornaments(@_) } || '';
7667 # Use what was passed in if we can't determine it ourselves.
7671 } ## end sub ornaments
7673 =head2 C<recallCommand>
7675 Sets the recall command, and builds a printable version which will appear in
7682 # If there is input, metaquote it. Add '\b' if it ends with a word
7685 $rc = quotemeta shift;
7686 $rc .= "\\b" if $rc =~ /\w$/;
7689 # Build it into a printable version.
7690 $prc = $rc; # Copy it
7691 $prc =~ s/\\b$//; # Remove trailing \b
7692 $prc =~ s/\\(.)/$1/g; # Remove escapes
7693 $prc; # Return the printable version
7694 } ## end sub recallCommand
7696 =head2 C<LineInfo> - where the line number information goes
7698 Called with no arguments, returns the file or pipe that line info should go to.
7700 Called with an argument (a file or a pipe), it opens that onto the
7701 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7702 file or pipe again to the caller.
7710 # If this is a valid "thing to be opened for output", tack a
7711 # '>' onto the front.
7712 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7714 # If this is a pipe, the stream points to a slave editor.
7715 $slave_editor = ( $stream =~ /^\|/ );
7717 # Open it up and unbuffer it.
7718 open( LINEINFO, $stream ) || _db_warn("Cannot open '$stream' for write");
7719 $LINEINFO = \*LINEINFO;
7720 $LINEINFO->autoflush(1);
7724 } ## end sub LineInfo
7726 =head1 COMMAND SUPPORT ROUTINES
7728 These subroutines provide functionality for various commands.
7730 =head2 C<list_modules>
7732 For the C<M> command: list modules loaded and their versions.
7733 Essentially just runs through the keys in %INC, picks each package's
7734 C<$VERSION> variable, gets the file name, and formats the information
7739 sub list_modules { # versions
7743 # keys are the "as-loaded" name, values are the fully-qualified path
7744 # to the file itself.
7746 $file = $_; # get the module name
7747 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7748 s,/,::,g; # change '/' to '::'
7749 s/^perl5db$/DB/; # Special case: debugger
7750 # moves to package DB
7751 s/^Term::ReadLine::readline$/readline/; # simplify readline
7753 # If the package has a $VERSION package global (as all good packages
7754 # should!) decode it and save as partial message.
7755 my $pkg_version = do { no strict 'refs'; ${ $_ . '::VERSION' } };
7756 if ( defined $pkg_version ) {
7757 $version{$file} = "$pkg_version from ";
7760 # Finish up the message with the file the package came from.
7761 $version{$file} .= $INC{$file};
7762 } ## end for (keys %INC)
7764 # Hey, dumpit() formats a hash nicely, so why not use it?
7765 dumpit( $OUT, \%version );
7766 } ## end sub list_modules
7770 Sets up the monster string used to format and print the help.
7772 =head3 HELP MESSAGE FORMAT
7774 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
7775 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
7776 easy to parse and portable, but which still allows the help to be a little
7777 nicer than just plain text.
7779 Essentially, you define the command name (usually marked up with C<< B<> >>
7780 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
7781 newline. The descriptive text can also be marked up in the same way. If you
7782 need to continue the descriptive text to another line, start that line with
7783 just tabs and then enter the marked-up text.
7785 If you are modifying the help text, I<be careful>. The help-string parser is
7786 not very sophisticated, and if you don't follow these rules it will mangle the
7787 help beyond hope until you fix the string.
7791 use vars qw($pre580_help);
7792 use vars qw($pre580_summary);
7796 # XXX: make sure there are tabs between the command and explanation,
7797 # or print_help will screw up your formatting if you have
7798 # eeevil ornaments enabled. This is an insane mess.
7801 Help is currently only available for the new 5.8 command set.
7802 No help is available for the old command set.
7803 We assume you know what you're doing if you switch to it.
7806 B<s> [I<expr>] Single step [in I<expr>].
7807 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7808 <B<CR>> Repeat last B<n> or B<s> command.
7809 B<r> Return from current subroutine.
7810 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7811 at the specified position.
7812 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7813 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7814 B<l> I<line> List single I<line>.
7815 B<l> I<subname> List first window of lines from subroutine.
7816 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7817 B<l> List next window of lines.
7818 B<-> List previous window of lines.
7819 B<v> [I<line>] View window around I<line>.
7820 B<.> Return to the executed line.
7821 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7822 I<filename> may be either the full name of the file, or a regular
7823 expression matching the full file name:
7824 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7825 Evals (with saved bodies) are considered to be filenames:
7826 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7827 (in the order of execution).
7828 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7829 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7830 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
7831 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7832 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth).
7833 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
7834 B<b> Sets breakpoint on current line)
7835 B<b> [I<line>] [I<condition>]
7836 Set breakpoint; I<line> defaults to the current execution line;
7837 I<condition> breaks if it evaluates to true, defaults to '1'.
7838 B<b> I<subname> [I<condition>]
7839 Set breakpoint at first line of subroutine.
7840 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7841 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7842 B<b> B<postpone> I<subname> [I<condition>]
7843 Set breakpoint at first line of subroutine after
7845 B<b> B<compile> I<subname>
7846 Stop after the subroutine is compiled.
7847 B<B> [I<line>] Delete the breakpoint for I<line>.
7848 B<B> I<*> Delete all breakpoints.
7849 B<a> [I<line>] I<command>
7850 Set an action to be done before the I<line> is executed;
7851 I<line> defaults to the current execution line.
7852 Sequence is: check for breakpoint/watchpoint, print line
7853 if necessary, do action, prompt user if necessary,
7856 B<A> [I<line>] Delete the action for I<line>.
7857 B<A> I<*> Delete all actions.
7858 B<w> I<expr> Add a global watch-expression.
7860 B<W> I<expr> Delete a global watch-expression.
7861 B<W> I<*> Delete all watch-expressions.
7862 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7863 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7864 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7865 B<x> I<expr> Evals expression in list context, dumps the result.
7866 B<m> I<expr> Evals expression in list context, prints methods callable
7867 on the first element of the result.
7868 B<m> I<class> Prints methods callable via the given class.
7869 B<M> Show versions of loaded modules.
7870 B<i> I<class> Prints nested parents of given class.
7871 B<e> Display current thread id.
7872 B<E> Display all thread ids the current one will be identified: <n>.
7873 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7875 B<<> ? List Perl commands to run before each prompt.
7876 B<<> I<expr> Define Perl command to run before each prompt.
7877 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7878 B<< *> Delete the list of perl commands to run before each prompt.
7879 B<>> ? List Perl commands to run after each prompt.
7880 B<>> I<expr> Define Perl command to run after each prompt.
7881 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7882 B<>>B< *> Delete the list of Perl commands to run after each prompt.
7883 B<{> I<db_command> Define debugger command to run before each prompt.
7884 B<{> ? List debugger commands to run before each prompt.
7885 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7886 B<{ *> Delete the list of debugger commands to run before each prompt.
7887 B<$prc> I<number> Redo a previous command (default previous command).
7888 B<$prc> I<-number> Redo number'th-to-last command.
7889 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7890 See 'B<O> I<recallCommand>' too.
7891 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7896 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7898 See 'B<O> I<shellBang>' too.
7899 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7900 B<save> I<file> Save current debugger session (actual history) to I<file>.
7901 B<rerun> Rerun session to current position.
7902 B<rerun> I<n> Rerun session to numbered command.
7903 B<rerun> I<-n> Rerun session to number'th-to-last command.
7904 B<H> I<-number> Display last number commands (default all).
7905 B<H> I<*> Delete complete history.
7906 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7907 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7908 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well.
7909 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7910 I<command> Execute as a perl statement in current package.
7911 B<R> Pure-man-restart of debugger, some of debugger state
7912 and command-line options may be lost.
7913 Currently the following settings are preserved:
7914 history, breakpoints and actions, debugger B<O>ptions
7915 and the following command-line options: I<-w>, I<-I>, I<-e>.
7917 B<o> [I<opt>] ... Set boolean option to true
7918 B<o> [I<opt>B<?>] Query options
7919 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7920 Set options. Use quotes if spaces in value.
7921 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7922 I<pager> program for output of \"|cmd\";
7923 I<tkRunning> run Tk while prompting (with ReadLine);
7924 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7925 I<inhibit_exit> Allows stepping off the end of the script.
7926 I<ImmediateStop> Debugger should stop as early as possible.
7927 I<RemotePort> Remote hostname:port for remote debugging
7928 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7929 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7930 I<compactDump>, I<veryCompact> change style of array and hash dump;
7931 I<globPrint> whether to print contents of globs;
7932 I<DumpDBFiles> dump arrays holding debugged files;
7933 I<DumpPackages> dump symbol tables of packages;
7934 I<DumpReused> dump contents of \"reused\" addresses;
7935 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7936 I<bareStringify> Do not print the overload-stringified value;
7937 Other options include:
7938 I<PrintRet> affects printing of return value after B<r> command,
7939 I<frame> affects printing messages on subroutine entry/exit.
7940 I<AutoTrace> affects printing messages on possible breaking points.
7941 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7942 I<ornaments> affects screen appearance of the command line.
7943 I<CreateTTY> bits control attempts to create a new TTY on events:
7944 1: on fork() 2: debugger is started inside debugger
7946 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7947 You can put additional initialization options I<TTY>, I<noTTY>,
7948 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7949 B<R> after you set them).
7951 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7952 B<h> Summary of debugger commands.
7953 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7954 B<h h> Long help for debugger commands
7955 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7956 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7957 Set B<\$DB::doccmd> to change viewer.
7959 Type '|h h' for a paged display if this was too hard to read.
7961 "; # Fix balance of vi % matching: }}}}
7963 # note: tabs in the following section are not-so-helpful
7964 $summary = <<"END_SUM";
7965 I<List/search source lines:> I<Control script execution:>
7966 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7967 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7968 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7969 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7970 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7971 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7972 I<Debugger controls:> B<L> List break/watch/actions
7973 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr]
7974 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7975 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7976 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7977 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7978 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7979 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7980 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7981 B<q> or B<^D> Quit B<R> Attempt a restart
7982 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7983 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7984 B<p> I<expr> Print expression (uses script's current package).
7985 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7986 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7987 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
7988 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7989 B<e> Display thread id B<E> Display all thread ids.
7990 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7993 # ')}}; # Fix balance of vi % matching
7995 # and this is really numb...
7998 B<s> [I<expr>] Single step [in I<expr>].
7999 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
8000 B<CR>> Repeat last B<n> or B<s> command.
8001 B<r> Return from current subroutine.
8002 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
8003 at the specified position.
8004 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
8005 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
8006 B<l> I<line> List single I<line>.
8007 B<l> I<subname> List first window of lines from subroutine.
8008 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
8009 B<l> List next window of lines.
8010 B<-> List previous window of lines.
8011 B<w> [I<line>] List window around I<line>.
8012 B<.> Return to the executed line.
8013 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
8014 I<filename> may be either the full name of the file, or a regular
8015 expression matching the full file name:
8016 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
8017 Evals (with saved bodies) are considered to be filenames:
8018 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
8019 (in the order of execution).
8020 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
8021 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
8022 B<L> List all breakpoints and actions.
8023 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
8024 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) .
8025 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
8026 B<b> [I<line>] [I<condition>]
8027 Set breakpoint; I<line> defaults to the current execution line;
8028 I<condition> breaks if it evaluates to true, defaults to '1'.
8029 B<b> I<subname> [I<condition>]
8030 Set breakpoint at first line of subroutine.
8031 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
8032 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
8033 B<b> B<postpone> I<subname> [I<condition>]
8034 Set breakpoint at first line of subroutine after
8036 B<b> B<compile> I<subname>
8037 Stop after the subroutine is compiled.
8038 B<d> [I<line>] Delete the breakpoint for I<line>.
8039 B<D> Delete all breakpoints.
8040 B<a> [I<line>] I<command>
8041 Set an action to be done before the I<line> is executed;
8042 I<line> defaults to the current execution line.
8043 Sequence is: check for breakpoint/watchpoint, print line
8044 if necessary, do action, prompt user if necessary,
8046 B<a> [I<line>] Delete the action for I<line>.
8047 B<A> Delete all actions.
8048 B<W> I<expr> Add a global watch-expression.
8049 B<W> Delete all watch-expressions.
8050 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
8051 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
8052 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
8053 B<x> I<expr> Evals expression in list context, dumps the result.
8054 B<m> I<expr> Evals expression in list context, prints methods callable
8055 on the first element of the result.
8056 B<m> I<class> Prints methods callable via the given class.
8058 B<<> ? List Perl commands to run before each prompt.
8059 B<<> I<expr> Define Perl command to run before each prompt.
8060 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
8061 B<>> ? List Perl commands to run after each prompt.
8062 B<>> I<expr> Define Perl command to run after each prompt.
8063 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
8064 B<{> I<db_command> Define debugger command to run before each prompt.
8065 B<{> ? List debugger commands to run before each prompt.
8066 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
8067 B<$prc> I<number> Redo a previous command (default previous command).
8068 B<$prc> I<-number> Redo number'th-to-last command.
8069 B<$prc> I<pattern> Redo last command that started with I<pattern>.
8070 See 'B<O> I<recallCommand>' too.
8071 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
8076 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
8078 See 'B<O> I<shellBang>' too.
8079 B<source> I<file> Execute I<file> containing debugger commands (may nest).
8080 B<H> I<-number> Display last number commands (default all).
8081 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
8082 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
8083 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
8084 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
8085 I<command> Execute as a perl statement in current package.
8086 B<v> Show versions of loaded modules.
8087 B<R> Pure-man-restart of debugger, some of debugger state
8088 and command-line options may be lost.
8089 Currently the following settings are preserved:
8090 history, breakpoints and actions, debugger B<O>ptions
8091 and the following command-line options: I<-w>, I<-I>, I<-e>.
8093 B<O> [I<opt>] ... Set boolean option to true
8094 B<O> [I<opt>B<?>] Query options
8095 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
8096 Set options. Use quotes if spaces in value.
8097 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
8098 I<pager> program for output of \"|cmd\";
8099 I<tkRunning> run Tk while prompting (with ReadLine);
8100 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
8101 I<inhibit_exit> Allows stepping off the end of the script.
8102 I<ImmediateStop> Debugger should stop as early as possible.
8103 I<RemotePort> Remote hostname:port for remote debugging
8104 The following options affect what happens with B<V>, B<X>, and B<x> commands:
8105 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
8106 I<compactDump>, I<veryCompact> change style of array and hash dump;
8107 I<globPrint> whether to print contents of globs;
8108 I<DumpDBFiles> dump arrays holding debugged files;
8109 I<DumpPackages> dump symbol tables of packages;
8110 I<DumpReused> dump contents of \"reused\" addresses;
8111 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
8112 I<bareStringify> Do not print the overload-stringified value;
8113 Other options include:
8114 I<PrintRet> affects printing of return value after B<r> command,
8115 I<frame> affects printing messages on subroutine entry/exit.
8116 I<AutoTrace> affects printing messages on possible breaking points.
8117 I<maxTraceLen> gives max length of evals/args listed in stack trace.
8118 I<ornaments> affects screen appearance of the command line.
8119 I<CreateTTY> bits control attempts to create a new TTY on events:
8120 1: on fork() 2: debugger is started inside debugger
8122 During startup options are initialized from \$ENV{PERLDB_OPTS}.
8123 You can put additional initialization options I<TTY>, I<noTTY>,
8124 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
8125 B<R> after you set them).
8127 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
8128 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
8129 B<h h> Summary of debugger commands.
8130 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
8131 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
8132 Set B<\$DB::doccmd> to change viewer.
8134 Type '|h' for a paged display if this was too hard to read.
8136 "; # Fix balance of vi % matching: }}}}
8138 # note: tabs in the following section are not-so-helpful
8139 $pre580_summary = <<"END_SUM";
8140 I<List/search source lines:> I<Control script execution:>
8141 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8142 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8143 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
8144 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8145 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8146 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
8147 I<Debugger controls:> B<L> List break/watch/actions
8148 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
8149 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8150 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
8151 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8152 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
8153 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
8154 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8155 B<q> or B<^D> Quit B<R> Attempt a restart
8156 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8157 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8158 B<p> I<expr> Print expression (uses script's current package).
8159 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8160 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8161 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
8162 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8163 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8166 # ')}}; # Fix balance of vi % matching
8168 } ## end sub sethelp
8170 =head2 C<print_help()>
8172 Most of what C<print_help> does is just text formatting. It finds the
8173 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
8174 terminal control characters to simulate them (courtesy of
8175 C<Term::ReadLine::TermCap>).
8180 my $help_str = shift;
8182 # Restore proper alignment destroyed by eeevil I<> and B<>
8183 # ornaments: A pox on both their houses!
8185 # A help command will have everything up to and including
8186 # the first tab sequence padded into a field 16 (or if indented 20)
8187 # wide. If it's wider than that, an extra space will be added.
8189 ^ # only matters at start of line
8190 ( \040{4} | \t )* # some subcommands are indented
8191 ( < ? # so <CR> works
8192 [BI] < [^\t\n] + ) # find an eeevil ornament
8193 ( \t+ ) # original separation, discarded
8194 ( .* ) # this will now start (no earlier) than
8197 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
8198 my $clean = $command;
8199 $clean =~ s/[BI]<([^>]*)>/$1/g;
8201 # replace with this whole string:
8202 ($leadwhite ? " " x 4 : "")
8204 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
8209 $help_str =~ s{ # handle bold ornaments
8210 B < ( [^>] + | > ) >
8212 $Term::ReadLine::TermCap::rl_term_set[2]
8214 . $Term::ReadLine::TermCap::rl_term_set[3]
8217 $help_str =~ s{ # handle italic ornaments
8218 I < ( [^>] + | > ) >
8220 $Term::ReadLine::TermCap::rl_term_set[0]
8222 . $Term::ReadLine::TermCap::rl_term_set[1]
8226 print {$OUT} $help_str;
8229 } ## end sub print_help
8233 This routine does a lot of gyrations to be sure that the pager is C<less>.
8234 It checks for C<less> masquerading as C<more> and records the result in
8235 C<$fixed_less> so we don't have to go through doing the stats again.
8239 use vars qw($fixed_less);
8242 if ($pager =~ /\bless\b/)
8246 elsif ($pager =~ /\bmore\b/)
8248 # Nope, set to more. See what's out there.
8249 my @st_more = stat('/usr/bin/more');
8250 my @st_less = stat('/usr/bin/less');
8252 # is it really less, pretending to be more?
8256 && $st_more[0] == $st_less[0]
8257 && $st_more[1] == $st_less[1]
8267 # We already know if this is set.
8268 return if $fixed_less;
8270 # changes environment!
8271 # 'r' added so we don't do (slow) stats again.
8272 $fixed_less = 1 if _calc_is_less();
8275 } ## end sub fix_less
8277 =head1 DIE AND WARN MANAGEMENT
8281 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
8282 to debug a debugger problem.
8284 It does its best to report the error that occurred, and then forces the
8285 program, debugger, and everything to die.
8291 # No entry/exit messages.
8294 # No return value prints.
8297 # set the abort signal handling to the default (just terminate).
8298 $SIG{'ABRT'} = 'DEFAULT';
8300 # If we enter the signal handler recursively, kill myself with an
8301 # abort signal (so we just terminate).
8302 kill 'ABRT', $$ if $panic++;
8304 # If we can show detailed info, do so.
8305 if ( defined &Carp::longmess ) {
8307 # Don't recursively enter the warn handler, since we're carping.
8308 local $SIG{__WARN__} = '';
8310 # Skip two levels before reporting traceback: we're skipping
8311 # mydie and confess.
8312 local $Carp::CarpLevel = 2; # mydie + confess
8314 # Tell us all about it.
8315 _db_warn( Carp::longmess("Signal @_") );
8318 # No Carp. Tell us about the signal as best we can.
8321 print $DB::OUT "Got signal @_\n";
8326 } ## end sub diesignal
8330 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
8331 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
8337 # No entry/exit trace.
8340 # No return value printing.
8343 # Turn off warn and die handling to prevent recursive entries to this
8345 local $SIG{__WARN__} = '';
8346 local $SIG{__DIE__} = '';
8348 # Load Carp if we can. If $^S is false (current thing being compiled isn't
8349 # done yet), we may not be able to do a require.
8350 eval { require Carp }
8351 if defined $^S; # If error/warning during compilation,
8352 # require may be broken.
8354 # Use the core warn() unless Carp loaded OK.
8356 "\nCannot print stack trace, load with -MCarp option to see stack" ),
8358 unless defined &Carp::longmess;
8360 # Save the current values of $single and $trace, and then turn them off.
8361 my ( $mysingle, $mytrace ) = ( $single, $trace );
8365 # We can call Carp::longmess without its being "debugged" (which we
8366 # don't want - we just want to use it!). Capture this for later.
8367 my $mess = Carp::longmess(@_);
8369 # Restore $single and $trace to their original values.
8370 ( $single, $trace ) = ( $mysingle, $mytrace );
8372 # Use the debugger's own special way of printing warnings to print
8373 # the stack trace message.
8379 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
8380 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
8381 single stepping and tracing during the call to C<Carp::longmess> to avoid
8382 debugging it - we just want to use it.
8384 If C<dieLevel> is zero, we let the program being debugged handle the
8385 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
8386 the debugger takes over all exception handling, printing a backtrace and
8387 displaying the exception via its C<dbwarn()> routine.
8394 local $SIG{__DIE__} = '';
8395 local $SIG{__WARN__} = '';
8396 if ( $dieLevel > 2 ) {
8397 local $SIG{__WARN__} = \&dbwarn;
8398 _db_warn(@_); # Yell no matter what
8401 if ( $dieLevel < 2 ) {
8402 die @_ if $^S; # in eval propagate
8405 # The code used to check $^S to see if compilation of the current thing
8406 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
8407 eval { require Carp };
8410 "\nCannot print stack trace, load with -MCarp option to see stack" )
8411 unless defined &Carp::longmess;
8413 # We do not want to debug this chunk (automatic disabling works
8414 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
8415 # get the stack trace from Carp::longmess (if possible), restore $signal
8416 # and $trace, and then die with the stack trace.
8417 my ( $mysingle, $mytrace ) = ( $single, $trace );
8423 package Carp; # Do not include us in the list
8424 eval { $mess = Carp::longmess(@_); };
8426 ( $single, $trace ) = ( $mysingle, $mytrace );
8430 =head2 C<warnlevel()>
8432 Set the C<$DB::warnLevel> variable that stores the value of the
8433 C<warnLevel> option. Calling C<warnLevel()> with a positive value
8434 results in the debugger taking over all warning handlers. Setting
8435 C<warnLevel> to zero leaves any warning handlers set up by the program
8436 being debugged in place.
8442 my $prevwarn = $SIG{__WARN__} unless $warnLevel;
8445 $SIG{__WARN__} = \&DB::dbwarn;
8448 $SIG{__WARN__} = $prevwarn;
8450 undef $SIG{__WARN__};
8454 } ## end sub warnLevel
8458 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
8459 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
8460 zero lets you use your own C<die()> handler.
8467 my $prevdie = $SIG{__DIE__} unless $dieLevel;
8471 # Always set it to dbdie() for non-zero values.
8472 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
8474 # No longer exists, so don't try to use it.
8475 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
8477 # If we've finished initialization, mention that stack dumps
8478 # are enabled, If dieLevel is 1, we won't stack dump if we die
8480 print $OUT "Stack dump during die enabled",
8481 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
8484 # XXX This is probably obsolete, given that diehard() is gone.
8485 print $OUT "Dump printed too.\n" if $dieLevel > 2;
8486 } ## end if ($dieLevel)
8488 # Put the old one back if there was one.
8490 $SIG{__DIE__} = $prevdie;
8491 print $OUT "Default die handler restored.\n";
8493 undef $SIG{__DIE__};
8494 print $OUT "Die handler removed.\n";
8498 } ## end sub dieLevel
8500 =head2 C<signalLevel>
8502 Number three in a series: set C<signalLevel> to zero to keep your own
8503 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
8504 takes over and handles them with C<DB::diesignal()>.
8510 my $prevsegv = $SIG{SEGV} unless $signalLevel;
8511 my $prevbus = $SIG{BUS} unless $signalLevel;
8512 $signalLevel = shift;
8514 $SIG{SEGV} = \&DB::diesignal;
8515 $SIG{BUS} = \&DB::diesignal;
8518 $SIG{SEGV} = $prevsegv;
8519 $SIG{BUS} = $prevbus;
8523 } ## end sub signalLevel
8525 =head1 SUBROUTINE DECODING SUPPORT
8527 These subroutines are used during the C<x> and C<X> commands to try to
8528 produce as much information as possible about a code reference. They use
8529 L<Devel::Peek> to try to find the glob in which this code reference lives
8530 (if it does) - this allows us to actually code references which correspond
8531 to named subroutines (including those aliased via glob assignment).
8533 =head2 C<CvGV_name()>
8535 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
8536 via that routine. If this fails, return the reference again (when the
8537 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
8543 my $name = CvGV_name_or_bust($in);
8544 defined $name ? $name : $in;
8547 =head2 C<CvGV_name_or_bust> I<coderef>
8549 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
8550 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
8551 find a glob for this ref.
8553 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
8557 use vars qw($skipCvGV);
8559 sub CvGV_name_or_bust {
8561 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
8562 return unless ref $in;
8563 $in = \&$in; # Hard reference...
8564 eval { require Devel::Peek; 1 } or return;
8565 my $gv = Devel::Peek::CvGV($in) or return;
8566 *$gv{PACKAGE} . '::' . *$gv{NAME};
8567 } ## end sub CvGV_name_or_bust
8571 A utility routine used in various places; finds the file where a subroutine
8572 was defined, and returns that filename and a line-number range.
8574 Tries to use C<@sub> first; if it can't find it there, it tries building a
8575 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
8576 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
8577 this way, it brute-force searches C<%sub>, checking for identical references.
8581 sub _find_sub_helper {
8584 return unless defined &$subr;
8585 my $name = CvGV_name_or_bust($subr);
8587 $data = $sub{$name} if defined $name;
8588 return $data if defined $data;
8591 $subr = \&$subr; # Hard reference
8594 $s = $_, last if $subr eq \&$_;
8609 return ( $sub{$subr} || _find_sub_helper($subr) );
8610 } ## end sub find_sub
8614 A subroutine that uses the utility function C<methods_via> to find all the
8615 methods in the class corresponding to the current reference and in
8624 # Figure out the class - either this is the class or it's a reference
8625 # to something blessed into that class.
8627 $class = ref $class if ref $class;
8631 # Show the methods that this class has.
8632 methods_via( $class, '', 1 );
8634 # Show the methods that UNIVERSAL has.
8635 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
8636 } ## end sub methods
8638 =head2 C<methods_via($class, $prefix, $crawl_upward)>
8640 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
8641 all the parent class methods. C<$class> is the name of the next class to
8642 try; C<$prefix> is the message prefix, which gets built up as we go up the
8643 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
8644 higher in the C<@ISA> tree, 0 if we should stop.
8650 # If we've processed this class already, just quit.
8652 return if $seen{$class}++;
8654 # This is a package that is contributing the methods we're about to print.
8656 my $prepend = $prefix ? "via $prefix: " : '';
8659 # Extract from all the symbols in this class.
8660 my $class_ref = do { no strict "refs"; \%{$class . '::'} };
8661 while (my ($name, $glob) = each %$class_ref) {
8662 # references directly in the symbol table are Proxy Constant
8663 # Subroutines, and are by their very nature defined
8664 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8665 # to a subroutine reference, which can be tested by defined.
8666 # $glob might also be the value -1 (from sub foo;)
8667 # or (say) '$$' (from sub foo ($$);)
8668 # \$glob will be SCALAR in both cases.
8669 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8670 && !$seen{$name}++) {
8671 push @to_print, "$prepend$name\n";
8678 print $DB::OUT $_ foreach sort @to_print;
8681 # If the $crawl_upward argument is false, just quit here.
8682 return unless shift;
8684 # $crawl_upward true: keep going up the tree.
8685 # Find all the classes this one is a subclass of.
8686 my $class_ISA_ref = do { no strict "refs"; \@{"${class}::ISA"} };
8687 for my $name ( @$class_ISA_ref ) {
8689 # Set up the new prefix.
8690 $prepend = $prefix ? $prefix . " -> $name" : $name;
8692 # Crawl up the tree and keep trying to crawl up.
8693 methods_via( $name, $prepend, 1 );
8695 } ## end sub methods_via
8697 =head2 C<setman> - figure out which command to use to show documentation
8699 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8704 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|NetWare)\z/s
8705 ? "man" # O Happy Day!
8706 : "perldoc"; # Alas, poor unfortunates
8709 =head2 C<runman> - run the appropriate command to show documentation
8711 Accepts a man page name; runs the appropriate command to display it (set up
8712 during debugger initialization). Uses C<_db_system()> to avoid mucking up the
8713 program's STDIN and STDOUT.
8717 my %_is_in_pods = (map { $_ => 1 }
8855 _db_system("$doccmd $doccmd");
8859 # this way user can override, like with $doccmd="man -Mwhatever"
8860 # or even just "man " to disable the path check.
8861 unless ( $doccmd eq 'man' ) {
8862 _db_system("$doccmd $page");
8866 $page = 'perl' if lc($page) eq 'help';
8869 my $man1dir = $Config::Config{'man1dir'};
8870 my $man3dir = $Config::Config{'man3dir'};
8871 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8873 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8874 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8875 chop $manpath if $manpath;
8877 # harmless if missing, I figure
8878 my $oldpath = $ENV{MANPATH};
8879 $ENV{MANPATH} = $manpath if $manpath;
8880 my $nopathopt = $^O =~ /dunno what goes here/;
8885 # I just *know* there are men without -M
8886 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8891 unless ( $page =~ /^perl\w/ ) {
8892 # do it this way because its easier to slurp in to keep up to date - clunky though.
8893 if (exists($_is_in_pods{$page})) {
8894 CORE::system( $doccmd,
8895 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8899 } ## end if (CORE::system($doccmd...
8900 if ( defined $oldpath ) {
8901 $ENV{MANPATH} = $manpath;
8904 delete $ENV{MANPATH};
8908 #use Carp; # This did break, left for debugging
8910 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
8912 Because of the way the debugger interface to the Perl core is designed, any
8913 debugger package globals that C<DB::sub()> requires have to be defined before
8914 any subroutines can be called. These are defined in the second C<BEGIN> block.
8916 This block sets things up so that (basically) the world is sane
8917 before the debugger starts executing. We set up various variables that the
8918 debugger has to have set up before the Perl core starts running:
8924 The debugger's own filehandles (copies of STD and STDOUT for now).
8928 Characters for shell escapes, the recall command, and the history command.
8932 The maximum recursion depth.
8936 The size of a C<w> command's window.
8940 The before-this-line context to be printed in a C<v> (view a window around this line) command.
8944 The fact that we're not in a sub at all right now.
8948 The default SIGINT handler for the debugger.
8952 The appropriate value of the flag in C<$^D> that says the debugger is running
8956 The current debugger recursion level
8960 The list of postponed items and the C<$single> stack (XXX define this)
8964 That we want no return values and no subroutine entry/exit trace.
8970 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
8972 use vars qw($db_stop);
8974 BEGIN { # This does not compile, alas. (XXX eh?)
8975 $IN = \*STDIN; # For bugs before DB::OUT has been opened
8976 $OUT = \*STDERR; # For errors before DB::OUT has been opened
8978 # Define characters used by command parsing.
8979 $sh = '!'; # Shell escape (does not work)
8980 $rc = ','; # Recall command (does not work)
8981 @hist = ('?'); # Show history (does not work)
8982 @truehist = (); # Can be saved for replay (per session)
8984 # This defines the point at which you get the 'deep recursion'
8985 # warning. It MUST be defined or the debugger will not load.
8988 # Number of lines around the current one that are shown in the
8992 # How much before-the-current-line context the 'v' command should
8993 # use in calculating the start of the window it will display.
8996 # We're not in any sub yet, but we need this to be a defined value.
8999 # Set up the debugger's interrupt handler. It simply sets a flag
9000 # ($signal) that DB::DB() will check before each command is executed.
9001 $SIG{INT} = \&DB::catch;
9003 # The following lines supposedly, if uncommented, allow the debugger to
9004 # debug itself. Perhaps we can try that someday.
9005 # This may be enabled to debug debugger:
9006 #$warnLevel = 1 unless defined $warnLevel;
9007 #$dieLevel = 1 unless defined $dieLevel;
9008 #$signalLevel = 1 unless defined $signalLevel;
9010 # This is the flag that says "a debugger is running, please call
9011 # DB::DB and DB::sub". We will turn it on forcibly before we try to
9012 # execute anything in the user's context, because we always want to
9014 $db_stop = 0; # Compiler warning ...
9015 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
9017 # This variable records how many levels we're nested in debugging. Used
9018 # Used in the debugger prompt, and in determining whether it's all over or
9020 $level = 0; # Level of recursive debugging
9022 # "Triggers bug (?) in perl if we postpone this until runtime."
9023 # XXX No details on this yet, or whether we should fix the bug instead
9024 # of work around it. Stay tuned.
9027 # Used to track the current stack depth using the auto-stacked-variable
9029 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
9031 # Don't print return values on exiting a subroutine.
9034 # No extry/exit tracing.
9039 BEGIN { $^W = $ini_warn; } # Switch warnings back
9041 =head1 READLINE SUPPORT - COMPLETION FUNCTION
9045 C<readline> support - adds command completion to basic C<readline>.
9047 Returns a list of possible completions to C<readline> when invoked. C<readline>
9048 will print the longest common substring following the text already entered.
9050 If there is only a single possible completion, C<readline> will use it in full.
9052 This code uses C<map> and C<grep> heavily to create lists of possible
9053 completion. Think LISP in this section.
9059 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
9060 # $text is the text to be completed.
9061 # $line is the incoming line typed by the user.
9062 # $start is the start of the text to be completed in the incoming line.
9063 my ( $text, $line, $start ) = @_;
9065 # Save the initial text.
9066 # The search pattern is current package, ::, extract the next qualifier
9067 # Prefix and pack are set to undef.
9068 my ( $itext, $search, $prefix, $pack ) =
9069 ( $text, "^\Q${package}::\E([^:]+)\$" );
9071 =head3 C<b postpone|compile>
9077 Find all the subroutines that might match in this package
9081 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
9085 Include all the rest of the subs that are known
9089 C<grep> out the ones that match the text we have so far
9093 Return this as the list of possible completions
9099 return sort grep /^\Q$text/, ( keys %sub ),
9100 qw(postpone load compile), # subroutines
9101 ( map { /$search/ ? ($1) : () } keys %sub )
9102 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
9106 Get all the possible files from C<@INC> as it currently stands and
9107 select the ones that match the text so far.
9111 return sort grep /^\Q$text/, values %INC # files
9112 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
9114 =head3 C<V> (list variable) and C<m> (list modules)
9116 There are two entry points for these commands:
9118 =head4 Unqualified package names
9120 Get the top-level packages and grab everything that matches the text
9121 so far. For each match, recursively complete the partial packages to
9122 get all possible matching packages. Return this sorted list.
9126 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9127 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
9128 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
9130 =head4 Qualified package names
9132 Take a partially-qualified package and find all subpackages for it
9133 by getting all the subpackages for the package so far, matching all
9134 the subpackages against the text, and discarding all of them which
9135 start with 'main::'. Return this list.
9139 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9140 grep !/^main::/, grep /^\Q$text/,
9141 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () }
9142 do { no strict 'refs'; keys %{ $prefix . '::' } }
9143 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
9144 and $text =~ /^(.*[^:])::?(\w*)$/
9147 =head3 C<f> - switch files
9149 Here, we want to get a fully-qualified filename for the C<f> command.
9154 =item 1. The original source file itself
9156 =item 2. A file from C<@INC>
9158 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
9164 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
9165 # We might possibly want to switch to an eval (which has a "filename"
9166 # like '(eval 9)'), so we may need to clean up the completion text
9167 # before proceeding.
9168 $prefix = length($1) - length($text);
9173 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
9174 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
9175 out of C<%main::>, add the initial source file, and extract the ones that
9176 match the completion text so far.
9181 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
9183 } ## end if ($line =~ /^\|*f\s+(.*)/)
9185 =head3 Subroutine name completion
9187 We look through all of the defined subs (the keys of C<%sub>) and
9188 return both all the possible matches to the subroutine name plus
9189 all the matches qualified to the current package.
9193 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
9194 $text = substr $text, 1;
9196 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
9198 map { /$search/ ? ($1) : () }
9201 } ## end if ((substr $text, 0, ...
9203 =head3 Scalar, array, and hash completion: partially qualified package
9205 Much like the above, except we have to do a little more cleanup:
9209 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
9217 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
9221 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
9227 Figure out the prefix vs. what needs completing.
9231 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
9238 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
9244 map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
9252 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.
9256 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9257 return db_complete( $out[0], $line, $start );
9260 # Return the list of possibles.
9263 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
9269 =head3 Symbol completion: current package or package C<main>.
9273 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
9280 If it's C<main>, delete main to just get C<::> leading.
9284 $pack = ( $package eq 'main' ? '' : $package ) . '::';
9290 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
9294 $prefix = substr $text, 0, 1;
9295 $text = substr $text, 1;
9303 We look for the lexical scope above DB::DB and auto-complete lexical variables
9304 if PadWalker could be loaded.
9308 if (not $text =~ /::/ and eval { require PadWalker } ) {
9311 my @info = caller($level);
9315 last if $info[3] eq 'DB::DB';
9318 my $lexicals = PadWalker::peek_my($level);
9319 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
9327 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
9331 push @out, map "$prefix$_", grep /^\Q$text/,
9332 ( grep /^_?[a-zA-Z]/, keys %$pack ),
9333 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
9337 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
9343 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9344 return db_complete( $out[0], $line, $start );
9347 # Return the list of possibles.
9349 } ## end if ($text =~ /^[\$@%]/)
9353 We use C<option_val()> to look up the current value of the option. If there's
9354 only a single value, we complete the command in such a way that it is a
9355 complete command for setting the option in question. If there are multiple
9356 possible values, we generate a command consisting of the option plus a trailing
9357 question mark, which, if executed, will list the current value of the option.
9361 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
9362 { # Options after space
9363 # We look for the text to be matched in the list of possible options,
9364 # and fetch the current value.
9365 my @out = grep /^\Q$text/, @options;
9366 my $val = option_val( $out[0], undef );
9368 # Set up a 'query option's value' command.
9370 if ( not defined $val or $val =~ /[\n\r]/ ) {
9372 # There's really nothing else we can do.
9375 # We have a value. Create a proper option-setting command.
9376 elsif ( $val =~ /\s/ ) {
9378 # XXX This may be an extraneous variable.
9381 # We'll want to quote the string (because of the embedded
9382 # whtespace), but we want to make sure we don't end up with
9383 # mismatched quote characters. We try several possibilities.
9384 foreach my $l ( split //, qq/\"\'\#\|/ ) {
9386 # If we didn't find this quote character in the value,
9387 # quote it using this quote character.
9388 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
9390 } ## end elsif ($val =~ /\s/)
9392 # Don't need any quotes.
9397 # If there were multiple possible values, return '? ', which
9398 # makes the command into a query command. If there was just one,
9399 # have readline append that.
9400 $rl_attribs->{completer_terminator_character} =
9401 ( @out == 1 ? $out : '? ' );
9403 # Return list of possibilities.
9405 } ## end if ((substr $line, 0, ...
9407 =head3 Filename completion
9409 For entering filenames. We simply call C<readline>'s C<filename_list()>
9410 method with the completion text to get the possible completions.
9414 return $term->filename_list($text); # filenames
9416 } ## end sub db_complete
9418 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
9420 Functions that possibly ought to be somewhere else.
9430 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n";
9435 If we have $ini_pids, save it in the environment; else remove it from the
9436 environment. Used by the C<R> (restart) command.
9441 if ( defined($ini_pids) ) {
9442 $ENV{PERLDB_PIDS} = $ini_pids;
9445 delete( $ENV{PERLDB_PIDS} );
9447 } ## end sub clean_ENV
9449 # PERLDBf_... flag names from perl.h
9450 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
9453 %DollarCaretP_flags = (
9454 PERLDBf_SUB => 0x01, # Debug sub enter/exit
9455 PERLDBf_LINE => 0x02, # Keep line #
9456 PERLDBf_NOOPT => 0x04, # Switch off optimizations
9457 PERLDBf_INTER => 0x08, # Preserve more data
9458 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
9459 PERLDBf_SINGLE => 0x20, # Start with single-step on
9460 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
9461 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
9462 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
9463 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
9464 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
9465 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
9467 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
9468 # doesn't need to set it. It's provided for the benefit of profilers and
9469 # other code analysers.
9471 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
9474 sub parse_DollarCaretP_flags {
9479 foreach my $f ( split /\s*\|\s*/, $flags ) {
9481 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
9484 elsif ( $f =~ /^(\d+)$/ ) {
9487 elsif ( $f =~ /^DEFAULT$/i ) {
9488 $value = $DollarCaretP_flags{PERLDB_ALL};
9491 $f =~ /^(?:PERLDBf_)?(.*)$/i;
9492 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
9493 unless ( defined $value ) {
9495 "Unrecognized \$^P flag '$f'!\n",
9496 "Acceptable flags are: "
9497 . join( ', ', sort keys %DollarCaretP_flags ),
9498 ", and hexadecimal and decimal numbers.\n"
9508 sub expand_DollarCaretP_flags {
9509 my $DollarCaretP = shift;
9512 my $n = ( 1 << $_ );
9513 ( $DollarCaretP & $n )
9514 ? ( $DollarCaretP_flags_r{$n}
9515 || sprintf( '0x%x', $n ) )
9519 return @bits ? join( '|', @bits ) : 0;
9526 Rerun the current session to:
9528 rerun current position
9530 rerun 4 command number 4
9532 rerun -4 current command minus 4 (go back 4 steps)
9534 Whether this always makes sense, in the current context is unknowable, and is
9535 in part left as a useful exercise for the reader. This sub returns the
9536 appropriate arguments to rerun the current session.
9543 pop(@truehist); # strim
9544 unless (defined $truehist[$i]) {
9545 print "Unable to return to non-existent command: $i\n";
9547 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
9548 my @temp = @truehist; # store
9549 push(@DB::typeahead, @truehist); # saved
9550 @truehist = @hist = (); # flush
9551 @args = restart(); # setup
9552 get_list("PERLDB_HIST"); # clean
9553 set_list("PERLDB_HIST", @temp); # reset
9560 Restarting the debugger is a complex operation that occurs in several phases.
9561 First, we try to reconstruct the command line that was used to invoke Perl
9567 # I may not be able to resurrect you, but here goes ...
9569 "Warning: some settings and command-line options may be lost!\n";
9570 my ( @script, @flags, $cl );
9572 # If warn was on before, turn it on again.
9573 push @flags, '-w' if $ini_warn;
9575 # Rebuild the -I flags that were on the initial
9578 push @flags, '-I', $_;
9581 # Turn on taint if it was on before.
9582 push @flags, '-T' if ${^TAINT};
9584 # Arrange for setting the old INC:
9585 # Save the current @init_INC in the environment.
9586 set_list( "PERLDB_INC", @ini_INC );
9588 # If this was a perl one-liner, go to the "file"
9589 # corresponding to the one-liner read all the lines
9590 # out of it (except for the first one, which is going
9591 # to be added back on again when 'perl -d' runs: that's
9592 # the 'require perl5db.pl;' line), and add them back on
9593 # to the command line to be executed.
9595 my $lines = *{$main::{'_<-e'}}{ARRAY};
9596 for ( 1 .. $#$lines ) { # The first line is PERL5DB
9597 chomp( $cl = $lines->[$_] );
9598 push @script, '-e', $cl;
9600 } ## end if ($0 eq '-e')
9602 # Otherwise we just reuse the original name we had
9610 After the command line has been reconstructed, the next step is to save
9611 the debugger's status in environment variables. The C<DB::set_list> routine
9612 is used to save aggregate variables (both hashes and arrays); scalars are
9613 just popped into environment variables directly.
9617 # If the terminal supported history, grab it and
9618 # save that in the environment.
9619 set_list( "PERLDB_HIST",
9620 $term->Features->{getHistory}
9624 # Find all the files that were visited during this
9625 # session (i.e., the debugger had magic hashes
9626 # corresponding to them) and stick them in the environment.
9627 my @had_breakpoints = keys %had_breakpoints;
9628 set_list( "PERLDB_VISITED", @had_breakpoints );
9630 # Save the debugger options we chose.
9631 set_list( "PERLDB_OPT", %option );
9632 # set_list( "PERLDB_OPT", options2remember() );
9634 # Save the break-on-loads.
9635 set_list( "PERLDB_ON_LOAD", %break_on_load );
9639 The most complex part of this is the saving of all of the breakpoints. They
9640 can live in an awful lot of places, and we have to go through all of them,
9641 find the breakpoints, and then save them in the appropriate environment
9642 variable via C<DB::set_list>.
9646 # Go through all the breakpoints and make sure they're
9649 for ( 0 .. $#had_breakpoints ) {
9651 # We were in this file.
9652 my $file = $had_breakpoints[$_];
9654 # Grab that file's magic line hash.
9655 *dbline = $main::{ '_<' . $file };
9657 # Skip out if it doesn't exist, or if the breakpoint
9658 # is in a postponed file (we'll do postponed ones
9660 next unless %dbline or $postponed_file{$file};
9662 # In an eval. This is a little harder, so we'll
9663 # do more processing on that below.
9664 ( push @hard, $file ), next
9665 if $file =~ /^\(\w*eval/;
9667 # XXX I have no idea what this is doing. Yet.
9669 @add = %{ $postponed_file{$file} }
9670 if $postponed_file{$file};
9672 # Save the list of all the breakpoints for this file.
9673 set_list( "PERLDB_FILE_$_", %dbline, @add );
9675 # Serialize the extra data %breakpoints_data hash.
9677 set_list( "PERLDB_FILE_ENABLED_$_",
9678 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 }
9679 sort { $a <=> $b } keys(%dbline)
9681 } ## end for (0 .. $#had_breakpoints)
9683 # The breakpoint was inside an eval. This is a little
9684 # more difficult. XXX and I don't understand it.
9686 # Get over to the eval in question.
9687 *dbline = $main::{ '_<' . $_ };
9688 my ( $quoted, $sub, %subs, $line ) = quotemeta $_;
9689 for $sub ( keys %sub ) {
9690 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
9691 $subs{$sub} = [ $1, $2 ];
9695 "No subroutines in $_, ignoring breakpoints.\n";
9698 LINES: for $line ( keys %dbline ) {
9700 # One breakpoint per sub only:
9701 my ( $offset, $sub, $found );
9702 SUBS: for $sub ( keys %subs ) {
9705 $line # Not after the subroutine
9707 not defined $offset # Not caught
9713 $offset = $line - $subs{$sub}->[0];
9714 $offset = "+$offset", last SUBS
9716 } ## end if ($subs{$sub}->[1] >=...
9717 } ## end for $sub (keys %subs)
9718 if ( defined $offset ) {
9719 $postponed{$found} =
9720 "break $offset if $dbline{$line}";
9724 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
9726 } ## end for $line (keys %dbline)
9727 } ## end for (@hard)
9729 # Save the other things that don't need to be
9731 set_list( "PERLDB_POSTPONE", %postponed );
9732 set_list( "PERLDB_PRETYPE", @$pretype );
9733 set_list( "PERLDB_PRE", @$pre );
9734 set_list( "PERLDB_POST", @$post );
9735 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9737 # We are officially restarting.
9738 $ENV{PERLDB_RESTART} = 1;
9740 # We are junking all child debuggers.
9741 delete $ENV{PERLDB_PIDS}; # Restore ini state
9743 # Set this back to the initial pid.
9744 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9748 After all the debugger status has been saved, we take the command we built up
9749 and then return it, so we can C<exec()> it. The debugger will spot the
9750 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9751 from the environment.
9755 # And run Perl again. Add the "-d" flag, all the
9756 # flags we built up, the script (whether a one-liner
9757 # or a file), add on the -emacs flag for a slave editor,
9758 # and then the old arguments.
9760 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9766 =head1 END PROCESSING - THE C<END> BLOCK
9768 Come here at the very end of processing. We want to go into a
9769 loop where we allow the user to enter commands and interact with the
9770 debugger, but we don't want anything else to execute.
9772 First we set the C<$finished> variable, so that some commands that
9773 shouldn't be run after the end of program quit working.
9775 We then figure out whether we're truly done (as in the user entered a C<q>
9776 command, or we finished execution while running nonstop). If we aren't,
9777 we set C<$single> to 1 (causing the debugger to get control again).
9779 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9780 message and returns control to the debugger. Repeat.
9782 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9783 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9784 break, run to completion.).
9789 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9790 $fall_off_end = 1 unless $inhibit_exit;
9792 # Do not stop in at_exit() and destructors on exit:
9793 if ($fall_off_end or $runnonstop) {
9797 DB::fake::at_exit();
9801 =head1 PRE-5.8 COMMANDS
9803 Some of the commands changed function quite a bit in the 5.8 command
9804 realignment, so much so that the old code had to be replaced completely.
9805 Because we wanted to retain the option of being able to go back to the
9806 former command set, we moved the old code off to this section.
9808 There's an awful lot of duplicated code here. We've duplicated the
9809 comments to keep things clear.
9813 Does nothing. Used to I<turn off> commands.
9817 sub cmd_pre580_null {
9822 =head2 Old C<a> command.
9824 This version added actions if you supplied them, and deleted them
9833 # Argument supplied. Add the action.
9834 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9836 # If the line isn't there, use the current line.
9837 my $i = $1 || $line;
9840 # If there is an action ...
9843 # ... but the line isn't breakable, skip it.
9844 if ( $dbline[$i] == 0 ) {
9845 print $OUT "Line $i may not have an action.\n";
9849 # ... and the line is breakable:
9850 # Mark that there's an action in this file.
9851 $had_breakpoints{$filename} |= 2;
9853 # Delete any current action.
9854 $dbline{$i} =~ s/\0[^\0]*//;
9856 # Add the new action, continuing the line as needed.
9857 $dbline{$i} .= "\0" . action($j);
9859 } ## end if (length $j)
9861 # No action supplied.
9864 # Delete the action.
9865 $dbline{$i} =~ s/\0[^\0]*//;
9867 # Mark as having no break or action if nothing's left.
9868 delete $dbline{$i} if $dbline{$i} eq '';
9870 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9871 } ## end sub cmd_pre580_a
9873 =head2 Old C<b> command
9885 if ( $cmd =~ /^load\b\s*(.*)/ ) {
9891 # b compile|postpone <some sub> [<condition>]
9892 # The interpreter actually traps this one for us; we just put the
9893 # necessary condition in the %postponed hash.
9894 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
9896 # Capture the condition if there is one. Make it true if none.
9897 my $cond = length $3 ? $3 : '1';
9899 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
9900 # if it was 'compile'.
9901 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
9903 # De-Perl4-ify the name - ' separators to ::.
9904 $subname =~ s/\'/::/g;
9906 # Qualify it into the current package unless it's already qualified.
9907 $subname = "${package}::" . $subname
9908 unless $subname =~ /::/;
9910 # Add main if it starts with ::.
9911 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
9913 # Save the break type for this sub.
9914 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
9915 } ## end elsif ($cmd =~ ...
9917 # b <sub name> [<condition>]
9918 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
9920 my $cond = length $2 ? $2 : '1';
9921 cmd_b_sub( $subname, $cond );
9923 # b <line> [<condition>].
9924 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9925 my $i = $1 || $dbline;
9926 my $cond = length $2 ? $2 : '1';
9927 cmd_b_line( $i, $cond );
9929 } ## end sub cmd_pre580_b
9931 =head2 Old C<D> command.
9933 Delete all breakpoints unconditionally.
9940 if ( $cmd =~ /^\s*$/ ) {
9941 print $OUT "Deleting all breakpoints...\n";
9943 # %had_breakpoints lists every file that had at least one
9946 for $file ( keys %had_breakpoints ) {
9948 # Switch to the desired file temporarily.
9949 local *dbline = $main::{ '_<' . $file };
9954 # For all lines in this file ...
9955 for my $i (1 .. $max) {
9957 # If there's a breakpoint or action on this line ...
9958 if ( defined $dbline{$i} ) {
9960 # ... remove the breakpoint.
9961 $dbline{$i} =~ s/^[^\0]+//;
9962 if ( $dbline{$i} =~ s/^\0?$// ) {
9964 # Remove the entry altogether if no action is there.
9967 } ## end if (defined $dbline{$i...
9968 } ## end for my $i (1 .. $max)
9970 # If, after we turn off the "there were breakpoints in this file"
9971 # bit, the entry in %had_breakpoints for this file is zero,
9972 # we should remove this file from the hash.
9973 if ( not $had_breakpoints{$file} &= ~1 ) {
9974 delete $had_breakpoints{$file};
9976 } ## end for $file (keys %had_breakpoints)
9978 # Kill off all the other breakpoints that are waiting for files that
9979 # haven't been loaded yet.
9981 undef %postponed_file;
9982 undef %break_on_load;
9983 } ## end if ($cmd =~ /^\s*$/)
9984 } ## end sub cmd_pre580_D
9986 =head2 Old C<h> command
9988 Print help. Defaults to printing the long-form help; the 5.8 version
9989 prints the summary by default.
9997 # Print the *right* help, long format.
9998 if ( $cmd =~ /^\s*$/ ) {
9999 print_help($pre580_help);
10002 # 'h h' - explicitly-requested summary.
10003 elsif ( $cmd =~ /^h\s*/ ) {
10004 print_help($pre580_summary);
10007 # Find and print a command's help.
10008 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
10009 my $asked = $1; # for proper errmsg
10010 my $qasked = quotemeta($asked); # for searching
10011 # XXX: finds CR but not <CR>
10015 (?:[IB]<) # Optional markup
10016 $qasked # The command name
10023 ( # The command help:
10025 (?:[IB]<) # Optional markup
10026 $qasked # The command name
10027 ([\s\S]*?) # Lines starting with tabs
10031 ) # Line not starting with space
10032 # (Next command's help)
10036 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
10040 print_help("B<$asked> is not a debugger command.\n");
10042 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
10043 } ## end sub cmd_pre580_h
10045 =head2 Old C<W> command
10047 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
10055 # Delete all watch expressions.
10056 if ( $cmd =~ /^$/ ) {
10058 # No watching is going on.
10061 # Kill all the watch expressions and values.
10062 @to_watch = @old_watch = ();
10065 # Add a watch expression.
10066 elsif ( $cmd =~ /^(.*)/s ) {
10068 # add it to the list to be watched.
10069 push @to_watch, $1;
10071 # Get the current value of the expression.
10072 # Doesn't handle expressions returning list values!
10074 my ($val) = DB::eval();
10075 $val = ( defined $val ) ? "'$val'" : 'undef';
10078 push @old_watch, $val;
10080 # We're watching stuff.
10083 } ## end elsif ($cmd =~ /^(.*)/s)
10084 } ## end sub cmd_pre580_W
10086 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
10088 The debugger used to have a bunch of nearly-identical code to handle
10089 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
10090 C<cmd_prepost> unify all this into one set of code to handle the
10091 appropriate actions.
10093 =head2 C<cmd_pre590_prepost>
10095 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
10096 do something destructive. In pre 5.8 debuggers, the default action was to
10097 delete all the actions.
10101 sub cmd_pre590_prepost {
10103 my $line = shift || '*';
10104 my $dbline = shift;
10106 return cmd_prepost( $cmd, $line, $dbline );
10107 } ## end sub cmd_pre590_prepost
10109 =head2 C<cmd_prepost>
10111 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
10112 Since the lists of actions are all held in arrays that are pointed to by
10113 references anyway, all we have to do is pick the right array reference and
10114 then use generic code to all, delete, or list actions.
10121 # No action supplied defaults to 'list'.
10122 my $line = shift || '?';
10124 # Figure out what to put in the prompt.
10127 # Make sure we have some array or another to address later.
10128 # This means that if ssome reason the tests fail, we won't be
10129 # trying to stash actions or delete them from the wrong place.
10132 # < - Perl code to run before prompt.
10133 if ( $cmd =~ /^\</o ) {
10134 $which = 'pre-perl';
10138 # > - Perl code to run after prompt.
10139 elsif ( $cmd =~ /^\>/o ) {
10140 $which = 'post-perl';
10144 # { - first check for properly-balanced braces.
10145 elsif ( $cmd =~ /^\{/o ) {
10146 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
10148 "$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n";
10151 # Properly balanced. Pre-prompt debugger actions.
10153 $which = 'pre-debugger';
10156 } ## end elsif ( $cmd =~ /^\{/o )
10158 # Did we find something that makes sense?
10160 print $OUT "Confused by command: $cmd\n";
10167 if ( $line =~ /^\s*\?\s*$/o ) {
10170 # Nothing there. Complain.
10171 print $OUT "No $which actions.\n";
10175 # List the actions in the selected list.
10176 print $OUT "$which commands:\n";
10177 foreach my $action (@$aref) {
10178 print $OUT "\t$cmd -- $action\n";
10181 } ## end if ( $line =~ /^\s*\?\s*$/o)
10183 # Might be a delete.
10185 if ( length($cmd) == 1 ) {
10186 if ( $line =~ /^\s*\*\s*$/o ) {
10188 # It's a delete. Get rid of the old actions in the
10191 print $OUT "All $cmd actions cleared.\n";
10195 # Replace all the actions. (This is a <, >, or {).
10196 @$aref = action($line);
10198 } ## end if ( length($cmd) == 1)
10199 elsif ( length($cmd) == 2 ) {
10201 # Add the action to the line. (This is a <<, >>, or {{).
10202 push @$aref, action($line);
10206 # <<<, >>>>, {{{{{{ ... something not a command.
10208 "Confused by strange length of $which command($cmd)...\n";
10210 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
10212 } ## end sub cmd_prepost
10216 Contains the C<at_exit> routine that the debugger uses to issue the
10217 C<Debugged program terminated ...> message after the program completes. See
10218 the C<END> block documentation for more details.
10225 "Debugged program terminated. Use 'q' to quit or 'R' to restart.";
10228 package DB; # Do not trace this 1; below!