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_09';
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);
1475 # Local autoflush to avoid rt#116769,
1476 # as calling IO::File methods causes an unresolvable loop
1477 # that results in debugger failure.
1479 my $o = select($_[0]);
1491 If there is a TTY, we have to determine who it belongs to before we can
1492 proceed. If this is a slave editor or graphical debugger (denoted by
1493 the first command-line switch being '-emacs'), we shift this off and
1494 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1500 # Is Perl being run from a slave editor or graphical debugger?
1501 # If so, don't use readline, and set $slave_editor = 1.
1502 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1507 #require Term::ReadLine;
1511 We then determine what the console should be on various systems:
1515 =item * Cygwin - We use C<stdin> instead of a separate device.
1519 if ( $^O eq 'cygwin' ) {
1521 # /dev/tty is binary. use stdin for textmode
1525 =item * Unix - use F</dev/tty>.
1529 elsif ( -e "/dev/tty" ) {
1530 $console = "/dev/tty";
1533 =item * Windows or MSDOS - use C<con>.
1537 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1541 =item * VMS - use C<sys$command>.
1547 # everything else is ...
1548 $console = "sys\$command";
1555 Several other systems don't use a specific console. We C<undef $console>
1556 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1557 with a slave editor).
1561 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1563 # /dev/tty is binary. use stdin for textmode
1567 if ( $^O eq 'NetWare' ) {
1569 # /dev/tty is binary. use stdin for textmode
1573 # In OS/2, we need to use STDIN to get textmode too, even though
1574 # it pretty much looks like Unix otherwise.
1575 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1582 If there is a TTY hanging around from a parent, we use that as the console.
1586 $console = $tty if defined $tty;
1588 =head2 SOCKET HANDLING
1590 The debugger is capable of opening a socket and carrying out a debugging
1591 session over the socket.
1593 If C<RemotePort> was defined in the options, the debugger assumes that it
1594 should try to start a debugging session on that port. It builds the socket
1595 and then tries to connect the input and output filehandles to it.
1599 # Handle socket stuff.
1601 if ( defined $remoteport ) {
1603 # If RemotePort was defined in the options, connect input and output
1605 $IN = $OUT = connect_remoteport();
1606 } ## end if (defined $remoteport)
1610 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1611 this is probably a situation where multiple debuggers are running (for example,
1612 a backticked command that starts up another debugger). We create a new IN and
1613 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1621 # Two debuggers running (probably a system or a backtick that invokes
1622 # the debugger itself under the running one). create a new IN and OUT
1623 # filehandle, and do the necessary mojo to create a new tty if we
1624 # know how, and we can.
1625 create_IN_OUT(4) if $CreateTTY & 4;
1628 # If we have a console, check to see if there are separate ins and
1629 # outs to open. (They are assumed identical if not.)
1631 my ( $i, $o ) = split /,/, $console;
1632 $o = $i unless defined $o;
1634 # read/write on in, or just read, or read on STDIN.
1636 || open( IN, "<$i" )
1637 || open( IN, "<&STDIN" );
1639 # read/write/create/clobber out, or write/create/clobber out,
1640 # or merge with STDERR, or merge with STDOUT.
1642 || open( OUT, ">$o" )
1643 || open( OUT, ">&STDERR" )
1644 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1646 } ## end if ($console)
1647 elsif ( not defined $console ) {
1649 # No console. Open STDIN.
1650 open( IN, "<&STDIN" );
1652 # merge with STDERR, or with STDOUT.
1653 open( OUT, ">&STDERR" )
1654 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1655 $console = 'STDIN/OUT';
1656 } ## end elsif (not defined $console)
1658 # Keep copies of the filehandles so that when the pager runs, it
1659 # can close standard input without clobbering ours.
1660 if ($console or (not defined($console))) {
1664 } ## end elsif (from if(defined $remoteport))
1666 # Unbuffer DB::OUT. We need to see responses right away.
1669 # Line info goes to debugger output unless pointed elsewhere.
1670 # Pointing elsewhere makes it possible for slave editors to
1671 # keep track of file and position. We have both a filehandle
1672 # and a I/O description to keep track of.
1673 $LINEINFO = $OUT unless defined $LINEINFO;
1674 $lineinfo = $console unless defined $lineinfo;
1675 # share($LINEINFO); # <- unable to share globs
1680 To finish initialization, we show the debugger greeting,
1681 and then call the C<afterinit()> subroutine if there is one.
1685 # Show the debugger greeting.
1686 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1687 unless ($runnonstop) {
1690 if ( $term_pid eq '-1' ) {
1691 print $OUT "\nDaughter DB session started...\n";
1694 print $OUT "\nLoading DB routines from $header\n";
1697 $slave_editor ? "enabled" : "available", ".\n"
1700 "\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
1701 } ## end else [ if ($term_pid eq '-1')
1702 } ## end unless ($runnonstop)
1703 } ## end else [ if ($notty)
1705 # XXX This looks like a bug to me.
1706 # Why copy to @ARGS and then futz with @args?
1709 # Make sure backslashes before single quotes are stripped out, and
1710 # keep args unless they are numeric (XXX why?)
1711 # s/\'/\\\'/g; # removed while not justified understandably
1712 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1715 # If there was an afterinit() sub defined, call it. It will get
1716 # executed in our scope, so it can fiddle with debugger globals.
1717 if ( defined &afterinit ) { # May be defined in $rcfile
1721 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1722 use vars qw($I_m_init);
1726 ############################################################ Subroutines
1732 This gigantic subroutine is the heart of the debugger. Called before every
1733 statement, its job is to determine if a breakpoint has been reached, and
1734 stop if so; read commands from the user, parse them, and execute
1735 them, and then send execution off to the next statement.
1737 Note that the order in which the commands are processed is very important;
1738 some commands earlier in the loop will actually alter the C<$cmd> variable
1739 to create other commands to be executed later. This is all highly I<optimized>
1740 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1741 see what's happening in any given command.
1745 # $cmd cannot be an our() variable unfortunately (possible perl bug?).
1775 sub _DB__determine_if_we_should_break
1777 # if we have something here, see if we should break.
1778 # $stop is lexical and local to this block - $action on the other hand
1783 && _is_breakpoint_enabled($filename, $line)
1784 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1787 # Stop if the stop criterion says to just stop.
1788 if ( $stop eq '1' ) {
1792 # It's a conditional stop; eval it in the user's context and
1793 # see if we should stop. If so, remove the one-time sigil.
1795 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1797 # If the breakpoint is temporary, then delete its enabled status.
1798 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1799 _cancel_breakpoint_temp_enabled_status($filename, $line);
1802 } ## end if ($dbline{$line} && ...
1805 sub _DB__is_finished {
1806 if ($finished and $level <= 1) {
1815 sub _DB__read_next_cmd
1819 # We have a terminal, or can get one ...
1824 # ... and it belogs to this PID or we get one for this PID ...
1825 if ($term_pid != $$) {
1829 # ... and we got a line of command input ...
1830 $cmd = DB::readline(
1831 "$pidprompt $tid DB"
1834 . ( '>' x $level ) . " "
1837 return defined($cmd);
1840 sub _DB__trim_command_and_return_first_component {
1843 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1844 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1846 my ($verb, $args) = $cmd =~ m{\A(\S*)\s*(.*)}s;
1848 $obj->cmd_verb($verb);
1849 $obj->cmd_args($args);
1854 sub _DB__handle_f_command {
1857 if ($file = $obj->cmd_args) {
1858 # help for no arguments (old-style was return from sub).
1861 "The old f command is now the r command.\n"; # hint
1862 print $OUT "The new f command switches filenames.\n";
1864 } ## end if (!$file)
1866 # if not in magic file list, try a close match.
1867 if ( !defined $main::{ '_<' . $file } ) {
1868 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1870 $try = substr( $try, 2 );
1871 print $OUT "Choosing $try matching '$file':\n";
1874 } ## end if (($try) = grep(m#^_<.*$file#...
1875 } ## end if (!defined $main::{ ...
1877 # If not successfully switched now, we failed.
1878 if ( !defined $main::{ '_<' . $file } ) {
1879 print $OUT "No file matching '$file' is loaded.\n";
1883 # We switched, so switch the debugger internals around.
1884 elsif ( $file ne $filename ) {
1885 *dbline = $main::{ '_<' . $file };
1890 } ## end elsif ($file ne $filename)
1892 # We didn't switch; say we didn't.
1894 print $OUT "Already in $file.\n";
1902 sub _DB__handle_dot_command {
1906 if ($obj->_is_full('.')) {
1907 $incr = -1; # stay at current line
1909 # Reset everything to the old location.
1911 $filename = $filename_ini;
1912 *dbline = $main::{ '_<' . $filename };
1916 print_lineinfo($obj->position());
1923 sub _DB__handle_y_command {
1926 if (my ($match_level, $match_vars)
1927 = $obj->cmd_args =~ /\A(?:(\d*)\s*(.*))?\z/) {
1929 # See if we've got the necessary support.
1930 if (!eval { require PadWalker; PadWalker->VERSION(0.08) }) {
1934 ? "PadWalker module not found - please install\n"
1940 # Load up dumpvar if we don't have it. If we can, that is.
1941 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1942 defined &main::dumpvar
1943 or print $OUT "dumpvar.pl not available.\n"
1946 # Got all the modules we need. Find them and print them.
1947 my @vars = split( ' ', $match_vars || '' );
1950 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
1952 # Oops. Can't find it.
1959 # Show the desired vars with dumplex().
1960 my $savout = select($OUT);
1962 # Have dumplex dump the lexicals.
1963 foreach my $key (sort keys %$h) {
1964 dumpvar::dumplex( $key, $h->{$key},
1965 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
1973 sub _DB__handle_c_command {
1976 my $i = $obj->cmd_args;
1978 if ($i =~ m#\A[\w:]*\z#) {
1980 # Hey, show's over. The debugged program finished
1981 # executing already.
1982 next CMD if _DB__is_finished();
1984 # Capture the place to put a one-time break.
1987 # Probably not needed, since we finish an interactive
1988 # sub-session anyway...
1989 # local $filename = $filename;
1990 # local *dbline = *dbline; # XXX Would this work?!
1992 # The above question wonders if localizing the alias
1993 # to the magic array works or not. Since it's commented
1994 # out, we'll just leave that to speculation for now.
1996 # If the "subname" isn't all digits, we'll assume it
1997 # is a subroutine name, and try to find it.
1998 if ( $subname =~ /\D/ ) { # subroutine name
1999 # Qualify it to the current package unless it's
2000 # already qualified.
2001 $subname = $package . "::" . $subname
2002 unless $subname =~ /::/;
2004 # find_sub will return "file:line_number" corresponding
2005 # to where the subroutine is defined; we call find_sub,
2006 # break up the return value, and assign it in one
2008 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2010 # Force the line number to be numeric.
2013 # If we got a line number, we found the sub.
2016 # Switch all the debugger's internals around so
2017 # we're actually working with that file.
2019 *dbline = $main::{ '_<' . $filename };
2021 # Mark that there's a breakpoint in this file.
2022 $had_breakpoints{$filename} |= 1;
2024 # Scan forward to the first executable line
2025 # after the 'sub whatever' line.
2028 while ($dbline[$_line_num] == 0 && $_line_num< $max)
2035 # We didn't find a sub by that name.
2037 print $OUT "Subroutine $subname not found.\n";
2040 } ## end if ($subname =~ /\D/)
2042 # At this point, either the subname was all digits (an
2043 # absolute line-break request) or we've scanned through
2044 # the code following the definition of the sub, looking
2045 # for an executable, which we may or may not have found.
2047 # If $i (which we set $subname from) is non-zero, we
2048 # got a request to break at some line somewhere. On
2049 # one hand, if there wasn't any real subroutine name
2050 # involved, this will be a request to break in the current
2051 # file at the specified line, so we have to check to make
2052 # sure that the line specified really is breakable.
2054 # On the other hand, if there was a subname supplied, the
2055 # preceding block has moved us to the proper file and
2056 # location within that file, and then scanned forward
2057 # looking for the next executable line. We have to make
2058 # sure that one was found.
2060 # On the gripping hand, we can't do anything unless the
2061 # current value of $i points to a valid breakable line.
2066 if ( $dbline[$i] == 0 ) {
2067 print $OUT "Line $i not breakable.\n";
2071 # Yes. Set up the one-time-break sigil.
2072 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2073 _enable_breakpoint_temp_enabled_status($filename, $i);
2076 # Turn off stack tracing from here up.
2077 for my $j (0 .. $stack_depth) {
2086 sub _DB__handle_forward_slash_command {
2089 # The pattern as a string.
2090 use vars qw($inpat);
2092 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2094 # Remove the final slash.
2095 $inpat =~ s:([^\\])/$:$1:;
2097 # If the pattern isn't null ...
2098 if ( $inpat ne "" ) {
2100 # Turn of warn and die procesing for a bit.
2101 local $SIG{__DIE__};
2102 local $SIG{__WARN__};
2104 # Create the pattern.
2105 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2108 # Oops. Bad pattern. No biscuit.
2109 # Print the eval error and go back for more
2115 } ## end if ($inpat ne "")
2117 # Set up to stop on wrap-around.
2120 # Don't move off the current line.
2123 my $pat = $obj->pat;
2125 # Done in eval so nothing breaks if the pattern
2126 # does something weird.
2131 # Move ahead one line.
2134 # Wrap if we pass the last line.
2135 if ($start > $max) {
2139 # Stop if we have gotten back to this line again,
2140 last if ($start == $end);
2142 # A hit! (Note, though, that we are doing
2143 # case-insensitive matching. Maybe a qr//
2144 # expression would be better, so the user could
2145 # do case-sensitive matching if desired.
2146 if ($dbline[$start] =~ m/$pat/i) {
2147 if ($slave_editor) {
2148 # Handle proper escaping in the slave.
2149 print {$OUT} "\032\032$filename:$start:0\n";
2152 # Just print the line normally.
2153 print {$OUT} "$start:\t",$dbline[$start],"\n";
2155 # And quit since we found something.
2165 # If we wrapped, there never was a match.
2166 if ( $start == $end ) {
2167 print {$OUT} "/$pat/: not found\n";
2175 sub _DB__handle_question_mark_command {
2178 # ? - backward pattern search.
2179 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2181 # Get the pattern, remove trailing question mark.
2182 $inpat =~ s:([^\\])\?$:$1:;
2184 # If we've got one ...
2185 if ( $inpat ne "" ) {
2187 # Turn off die & warn handlers.
2188 local $SIG{__DIE__};
2189 local $SIG{__WARN__};
2190 eval '$inpat =~ m' . "\a$inpat\a";
2194 # Ouch. Not good. Print the error.
2199 } ## end if ($inpat ne "")
2201 # Where we are now is where to stop after wraparound.
2204 # Don't move away from this line.
2207 my $pat = $obj->pat;
2208 # Search inside the eval to prevent pattern badness
2216 # Wrap if we pass the first line.
2218 $start = $max if ($start <= 0);
2220 # Quit if we get back where we started,
2221 last if ($start == $end);
2224 if ($dbline[$start] =~ m/$pat/i) {
2225 if ($slave_editor) {
2226 # Yep, follow slave editor requirements.
2227 print $OUT "\032\032$filename:$start:0\n";
2230 # Yep, just print normally.
2231 print $OUT "$start:\t",$dbline[$start],"\n";
2240 # Say we failed if the loop never found anything,
2241 if ( $start == $end ) {
2242 print {$OUT} "?$pat?: not found\n";
2250 sub _DB__handle_restart_and_rerun_commands {
2253 my $cmd_cmd = $obj->cmd_verb;
2254 my $cmd_params = $obj->cmd_args;
2255 # R - restart execution.
2256 # rerun - controlled restart execution.
2257 if ($cmd_cmd eq 'rerun' or $cmd_params eq '') {
2258 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
2260 # Close all non-system fds for a clean restart. A more
2261 # correct method would be to close all fds that were not
2262 # open when the process started, but this seems to be
2263 # hard. See "debugger 'R'estart and open database
2264 # connections" on p5p.
2266 my $max_fd = 1024; # default if POSIX can't be loaded
2267 if (eval { require POSIX }) {
2268 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
2271 if (defined $max_fd) {
2272 foreach ($^F+1 .. $max_fd-1) {
2273 next unless open FD_TO_CLOSE, "<&=$_";
2278 # And run Perl again. We use exec() to keep the
2279 # PID stable (and that way $ini_pids is still valid).
2280 exec(@args) or print {$OUT} "exec failed: $!\n";
2288 sub _DB__handle_run_command_in_pager_command {
2291 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
2292 if ( $pager =~ /^\|/ ) {
2294 # Default pager is into a pipe. Redirect I/O.
2295 open( SAVEOUT, ">&STDOUT" )
2296 || _db_warn("Can't save STDOUT");
2297 open( STDOUT, ">&OUT" )
2298 || _db_warn("Can't redirect STDOUT");
2299 } ## end if ($pager =~ /^\|/)
2302 # Not into a pipe. STDOUT is safe.
2303 open( SAVEOUT, ">&OUT" ) || _db_warn("Can't save DB::OUT");
2306 # Fix up environment to record we have less if so.
2309 unless ( $obj->piped(scalar ( open( OUT, $pager ) ) ) ) {
2311 # Couldn't open pipe to pager.
2312 _db_warn("Can't pipe output to '$pager'");
2313 if ( $pager =~ /^\|/ ) {
2315 # Redirect I/O back again.
2316 open( OUT, ">&STDOUT" ) # XXX: lost message
2317 || _db_warn("Can't restore DB::OUT");
2318 open( STDOUT, ">&SAVEOUT" )
2319 || _db_warn("Can't restore STDOUT");
2321 } ## end if ($pager =~ /^\|/)
2324 # Redirect I/O. STDOUT already safe.
2325 open( OUT, ">&STDOUT" ) # XXX: lost message
2326 || _db_warn("Can't restore DB::OUT");
2329 } ## end unless ($piped = open(OUT,...
2331 # Set up broken-pipe handler if necessary.
2332 $SIG{PIPE} = \&DB::catch
2334 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
2337 # Save current filehandle, and put it back.
2338 $obj->selected(scalar( select(OUT) ));
2339 # Don't put it back if pager was a pipe.
2340 if ($cmd !~ /\A\|\|/)
2342 select($obj->selected());
2346 # Trim off the pipe symbols and run the command now.
2347 $cmd =~ s#\A\|+\s*##;
2354 sub _DB__handle_m_command {
2357 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2362 # m expr - set up DB::eval to do the work
2363 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2364 $onetimeDump = 'methods'; # method output gets used there
2370 sub _DB__at_end_of_every_command {
2373 # At the end of every command:
2376 # Unhook the pipe mechanism now.
2377 if ( $pager =~ /^\|/ ) {
2379 # No error from the child.
2382 # we cannot warn here: the handle is missing --tchrist
2383 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
2385 # most of the $? crud was coping with broken cshisms
2386 # $? is explicitly set to 0, so this never runs.
2388 print SAVEOUT "Pager '$pager' failed: ";
2390 print SAVEOUT "shell returned -1\n";
2393 print SAVEOUT ( $? & 127 )
2394 ? " (SIG#" . ( $? & 127 ) . ")"
2395 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
2398 print SAVEOUT "status ", ( $? >> 8 ), "\n";
2402 # Reopen filehandle for our output (if we can) and
2403 # restore STDOUT (if we can).
2404 open( OUT, ">&STDOUT" ) || _db_warn("Can't restore DB::OUT");
2405 open( STDOUT, ">&SAVEOUT" )
2406 || _db_warn("Can't restore STDOUT");
2408 # Turn off pipe exception handler if necessary.
2409 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
2411 # Will stop ignoring SIGPIPE if done like nohup(1)
2412 # does SIGINT but Perl doesn't give us a choice.
2413 } ## end if ($pager =~ /^\|/)
2416 # Non-piped "pager". Just restore STDOUT.
2417 open( OUT, ">&SAVEOUT" ) || _db_warn("Can't restore DB::OUT");
2420 # Close filehandle pager was using, restore the normal one
2424 if ($obj->selected() ne "") {
2425 select($obj->selected);
2431 } ## end if ($piped)
2436 sub _DB__handle_watch_expressions
2440 if ( $DB::trace & 2 ) {
2441 for my $n (0 .. $#DB::to_watch) {
2442 $DB::evalarg = $DB::to_watch[$n];
2443 local $DB::onetimeDump; # Tell DB::eval() to not output results
2445 # Fix context DB::eval() wants to return an array, but
2446 # we need a scalar here.
2447 my ($val) = join( "', '", DB::eval(@_) );
2448 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
2451 if ( $val ne $DB::old_watch[$n] ) {
2453 # Yep! Show the difference, and fake an interrupt.
2455 print {$DB::OUT} <<EOP;
2456 Watchpoint $n:\t$DB::to_watch[$n] changed:
2457 old value:\t$DB::old_watch[$n]
2460 $DB::old_watch[$n] = $val;
2461 } ## end if ($val ne $old_watch...
2462 } ## end for my $n (0 ..
2463 } ## end if ($trace & 2)
2470 # 'v' is the value (i.e: method name or subroutine ref).
2471 # 's' is subroutine.
2474 '-' => { t => 'm', v => '_handle_dash_command', },
2475 '.' => { t => 's', v => \&_DB__handle_dot_command, },
2476 '=' => { t => 'm', v => '_handle_equal_sign_command', },
2477 'H' => { t => 'm', v => '_handle_H_command', },
2478 'S' => { t => 'm', v => '_handle_S_command', },
2479 'T' => { t => 'm', v => '_handle_T_command', },
2480 'W' => { t => 'm', v => '_handle_W_command', },
2481 'c' => { t => 's', v => \&_DB__handle_c_command, },
2482 'f' => { t => 's', v => \&_DB__handle_f_command, },
2483 'm' => { t => 's', v => \&_DB__handle_m_command, },
2484 'n' => { t => 'm', v => '_handle_n_command', },
2485 'p' => { t => 'm', v => '_handle_p_command', },
2486 'q' => { t => 'm', v => '_handle_q_command', },
2487 'r' => { t => 'm', v => '_handle_r_command', },
2488 's' => { t => 'm', v => '_handle_s_command', },
2489 'save' => { t => 'm', v => '_handle_save_command', },
2490 'source' => { t => 'm', v => '_handle_source_command', },
2491 't' => { t => 'm', v => '_handle_t_command', },
2492 'w' => { t => 'm', v => '_handle_w_command', },
2493 'x' => { t => 'm', v => '_handle_x_command', },
2494 'y' => { t => 's', v => \&_DB__handle_y_command, },
2495 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, }
2497 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, }
2498 qw(enable disable)),
2500 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, },
2502 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, }
2503 qw(a A b B e E h i l L M o O P v w W)),
2508 # lock the debugger and get the thread id for the prompt
2512 my ($prefix, $after, $infix);
2518 if ($ENV{PERL5DB_THREADED}) {
2519 $tid = eval { "[".threads->tid."]" };
2525 my $obj = DB::Obj->new(
2527 position => \$position,
2530 explicit_stop => \$explicit_stop,
2532 cmd_args => \$cmd_args,
2533 cmd_verb => \$cmd_verb,
2536 selected => \$selected,
2540 $obj->_DB_on_init__initialize_globals(@_);
2542 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2543 # The code being debugged may have altered them.
2546 # Since DB::DB gets called after every line, we can use caller() to
2547 # figure out where we last were executing. Sneaky, eh? This works because
2548 # caller is returning all the extra information when called from the
2550 local ( $package, $filename, $line ) = caller;
2551 $filename_ini = $filename;
2553 # set up the context for DB::eval, so it can properly execute
2554 # code on behalf of the user. We add the package in so that the
2555 # code is eval'ed in the proper package (not in the debugger!).
2556 local $usercontext = _calc_usercontext($package);
2558 # Create an alias to the active file magical array to simplify
2560 local (*dbline) = $main::{ '_<' . $filename };
2562 # Last line in the program.
2565 _DB__determine_if_we_should_break(@_);
2567 # Preserve the current stop-or-not, and see if any of the W
2568 # (watch expressions) has changed.
2569 my $was_signal = $signal;
2571 # If we have any watch expressions ...
2572 _DB__handle_watch_expressions($obj);
2574 =head2 C<watchfunction()>
2576 C<watchfunction()> is a function that can be defined by the user; it is a
2577 function which will be run on each entry to C<DB::DB>; it gets the
2578 current package, filename, and line as its parameters.
2580 The watchfunction can do anything it likes; it is executing in the
2581 debugger's context, so it has access to all of the debugger's internal
2582 data structures and functions.
2584 C<watchfunction()> can control the debugger's actions. Any of the following
2585 will cause the debugger to return control to the user's program after
2586 C<watchfunction()> executes:
2592 Returning a false value from the C<watchfunction()> itself.
2596 Altering C<$single> to a false value.
2600 Altering C<$signal> to a false value.
2604 Turning off the C<4> bit in C<$trace> (this also disables the
2605 check for C<watchfunction()>. This can be done with
2613 # If there's a user-defined DB::watchfunction, call it with the
2614 # current package, filename, and line. The function executes in
2616 if ( $trace & 4 ) { # User-installed watch
2618 if watchfunction( $package, $filename, $line )
2621 and not( $trace & ~4 );
2622 } ## end if ($trace & 4)
2624 # Pick up any alteration to $signal in the watchfunction, and
2625 # turn off the signal now.
2626 $was_signal = $signal;
2629 =head2 GETTING READY TO EXECUTE COMMANDS
2631 The debugger decides to take control if single-step mode is on, the
2632 C<t> command was entered, or the user generated a signal. If the program
2633 has fallen off the end, we set things up so that entering further commands
2634 won't cause trouble, and we say that the program is over.
2638 # Make sure that we always print if asked for explicitly regardless
2639 # of $trace_to_depth .
2640 $explicit_stop = ($single || $was_signal);
2642 # Check to see if we should grab control ($single true,
2643 # trace set appropriately, or we got a signal).
2644 if ( $explicit_stop || ( $trace & 1 ) ) {
2645 $obj->_DB__grab_control(@_);
2646 } ## end if ($single || ($trace...
2650 If there's an action to be executed for the line we stopped at, execute it.
2651 If there are any preprompt actions, execute those as well.
2655 # If there's an action, do it now.
2661 # Are we nested another level (e.g., did we evaluate a function
2662 # that had a breakpoint in it at the debugger prompt)?
2663 if ( $single || $was_signal ) {
2665 # Yes, go down a level.
2666 local $level = $level + 1;
2668 # Do any pre-prompt actions.
2669 foreach $evalarg (@$pre) {
2673 # Complain about too much recursion if we passed the limit.
2675 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2678 # The line we're currently on. Set $incr to -1 to stay here
2679 # until we get a command that tells us to advance.
2681 $incr = -1; # for backward motion.
2683 # Tack preprompt debugger actions ahead of any actual input.
2684 @typeahead = ( @$pretype, @typeahead );
2686 =head2 WHERE ARE WE?
2688 XXX Relocate this section?
2690 The debugger normally shows the line corresponding to the current line of
2691 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2692 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2694 C<$incr> controls by how many lines the I<current> line should move forward
2695 after a command is executed. If set to -1, this indicates that the I<current>
2696 line shouldn't change.
2698 C<$start> is the I<current> line. It is used for things like knowing where to
2699 move forwards or backwards from when doing an C<L> or C<-> command.
2701 C<$max> tells the debugger where the last line of the current file is. It's
2702 used to terminate loops most often.
2704 =head2 THE COMMAND LOOP
2706 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2713 The outer part of the loop, starting at the C<CMD> label. This loop
2714 reads a command and then executes it.
2718 The inner part of the loop, starting at the C<PIPE> label. This part
2719 is wholly contained inside the C<CMD> block and only executes a command.
2720 Used to handle commands running inside a pager.
2724 So why have two labels to restart the loop? Because sometimes, it's easier to
2725 have a command I<generate> another command and then re-execute the loop to do
2726 the new command. This is faster, but perhaps a bit more convoluted.
2730 # The big command dispatch loop. It keeps running until the
2731 # user yields up control again.
2733 # If we have a terminal for input, and we get something back
2734 # from readline(), keep on processing.
2737 while (_DB__read_next_cmd($tid))
2741 # ... try to execute the input as debugger commands.
2743 # Don't stop running.
2746 # No signal is active.
2749 # Handle continued commands (ending with \):
2750 if ($cmd =~ s/\\\z/\n/) {
2751 $cmd .= DB::readline(" cont: ");
2755 =head4 The null command
2757 A newline entered by itself means I<re-execute the last command>. We grab the
2758 command out of C<$laststep> (where it was recorded previously), and copy it
2759 back into C<$cmd> to be executed below. If there wasn't any previous command,
2760 we'll do nothing below (no command will match). If there was, we also save it
2761 in the command history and fall through to allow the command parsing to pick
2766 # Empty input means repeat the last command.
2770 chomp($cmd); # get rid of the annoying extra newline
2771 if (length($cmd) >= 2) {
2772 push( @hist, $cmd );
2774 push( @truehist, $cmd );
2778 # This is a restart point for commands that didn't arrive
2779 # via direct user input. It allows us to 'redo PIPE' to
2780 # re-execute command processing without reading a new command.
2782 _DB__trim_command_and_return_first_component($obj);
2784 =head3 COMMAND ALIASES
2786 The debugger can create aliases for commands (these are stored in the
2787 C<%alias> hash). Before a command is executed, the command loop looks it up
2788 in the alias hash and substitutes the contents of the alias for the command,
2789 completely replacing it.
2793 # See if there's an alias for the command, and set it up if so.
2794 if ( $alias{$cmd_verb} ) {
2796 # Squelch signal handling; we want to keep control here
2797 # if something goes loco during the alias eval.
2798 local $SIG{__DIE__};
2799 local $SIG{__WARN__};
2801 # This is a command, so we eval it in the DEBUGGER's
2802 # scope! Otherwise, we can't see the special debugger
2803 # variables, or get to the debugger's subs. (Well, we
2804 # _could_, but why make it even more complicated?)
2805 eval "\$cmd =~ $alias{$cmd_verb}";
2808 print $OUT "Couldn't evaluate '$cmd_verb' alias: $@";
2811 _DB__trim_command_and_return_first_component($obj);
2812 } ## end if ($alias{$cmd_verb})
2814 =head3 MAIN-LINE COMMANDS
2816 All of these commands work up to and after the program being debugged has
2821 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2822 try to execute further, cleaning any restart-related stuff out of the
2823 environment, and executing with the last value of C<$?>.
2827 # All of these commands were remapped in perl 5.8.0;
2828 # we send them off to the secondary dispatcher (see below).
2829 $obj->_handle_special_char_cmd_wrapper_commands;
2830 _DB__trim_command_and_return_first_component($obj);
2832 if (my $cmd_rec = $cmd_lookup{$cmd_verb}) {
2833 my $type = $cmd_rec->{t};
2834 my $val = $cmd_rec->{v};
2838 elsif ($type eq 's') {
2843 =head4 C<t> - trace [n]
2845 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2846 If level is specified, set C<$trace_to_depth>.
2848 =head4 C<S> - list subroutines matching/not matching a pattern
2850 Walks through C<%sub>, checking to see whether or not to print the name.
2852 =head4 C<X> - list variables in current package
2854 Since the C<V> command actually processes this, just change this to the
2855 appropriate C<V> command and fall through.
2857 =head4 C<V> - list variables
2859 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2861 =head4 C<x> - evaluate and print an expression
2863 Hands the expression off to C<DB::eval>, setting it up to print the value
2864 via C<dumpvar.pl> instead of just printing it directly.
2866 =head4 C<m> - print methods
2868 Just uses C<DB::methods> to determine what methods are available.
2870 =head4 C<f> - switch files
2872 Switch to a different filename.
2874 =head4 C<.> - return to last-executed line.
2876 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2877 and then we look up the line in the magical C<%dbline> hash.
2879 =head4 C<-> - back one window
2881 We change C<$start> to be one window back; if we go back past the first line,
2882 we set it to be the first line. We ser C<$incr> to put us back at the
2883 currently-executing line, and then put a C<l $start +> (list one window from
2884 C<$start>) in C<$cmd> to be executed later.
2886 =head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
2888 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2889 problems, most notably that the default case of several commands destroying
2890 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2891 retain the old commands for those who were used to using them or who preferred
2892 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2893 deal with them instead of processing them in-line.
2895 =head4 C<y> - List lexicals in higher scope
2897 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2898 above the current one and then displays then using C<dumpvar.pl>.
2900 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2902 All of the commands below this point don't work after the program being
2903 debugged has ended. All of them check to see if the program has ended; this
2904 allows the commands to be relocated without worrying about a 'line of
2905 demarcation' above which commands can be entered anytime, and below which
2908 =head4 C<n> - single step, but don't trace down into subs
2910 Done by setting C<$single> to 2, which forces subs to execute straight through
2911 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2912 so a null command knows what to re-execute.
2914 =head4 C<s> - single-step, entering subs
2916 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2917 subs. Also saves C<s> as C<$lastcmd>.
2919 =head4 C<c> - run continuously, setting an optional breakpoint
2921 Most of the code for this command is taken up with locating the optional
2922 breakpoint, which is either a subroutine name or a line number. We set
2923 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2924 in this and all call levels above this one.
2926 =head4 C<r> - return from a subroutine
2928 For C<r> to work properly, the debugger has to stop execution again
2929 immediately after the return is executed. This is done by forcing
2930 single-stepping to be on in the call level above the current one. If
2931 we are printing return values when a C<r> is executed, set C<$doret>
2932 appropriately, and force us out of the command loop.
2934 =head4 C<T> - stack trace
2936 Just calls C<DB::print_trace>.
2938 =head4 C<w> - List window around current line.
2940 Just calls C<DB::cmd_w>.
2942 =head4 C<W> - watch-expression processing.
2944 Just calls C<DB::cmd_W>.
2946 =head4 C</> - search forward for a string in the source
2948 We take the argument and treat it as a pattern. If it turns out to be a
2949 bad one, we return the error we got from trying to C<eval> it and exit.
2950 If not, we create some code to do the search and C<eval> it so it can't
2955 _DB__handle_forward_slash_command($obj);
2957 =head4 C<?> - search backward for a string in the source
2959 Same as for C</>, except the loop runs backwards.
2963 _DB__handle_question_mark_command($obj);
2965 =head4 C<$rc> - Recall command
2967 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2968 that the terminal supports history). It find the the command required, puts it
2969 into C<$cmd>, and redoes the loop to execute it.
2973 # $rc - recall command.
2974 $obj->_handle_rc_recall_command;
2976 =head4 C<$sh$sh> - C<system()> command
2978 Calls the C<_db_system()> to handle the command. This keeps the C<STDIN> and
2979 C<STDOUT> from getting messed up.
2983 $obj->_handle_sh_command;
2985 =head4 C<$rc I<pattern> $rc> - Search command history
2987 Another command to manipulate C<@hist>: this one searches it with a pattern.
2988 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
2992 $obj->_handle_rc_search_history_command;
2994 =head4 C<$sh> - Invoke a shell
2996 Uses C<_db_system()> to invoke a shell.
3000 =head4 C<$sh I<command>> - Force execution of a command in a shell
3002 Like the above, but the command is passed to the shell. Again, we use
3003 C<_db_system()> to avoid problems with C<STDIN> and C<STDOUT>.
3005 =head4 C<H> - display commands in history
3007 Prints the contents of C<@hist> (if any).
3009 =head4 C<man, doc, perldoc> - look up documentation
3011 Just calls C<runman()> to print the appropriate document.
3015 $obj->_handle_doc_command;
3019 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3020 the bottom of the loop.
3022 =head4 C<=> - define command alias
3024 Manipulates C<%alias> to add or list command aliases.
3026 =head4 C<source> - read commands from a file.
3028 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3031 =head4 C<enable> C<disable> - enable or disable breakpoints
3033 This enables or disables breakpoints.
3035 =head4 C<save> - send current history to a file
3037 Takes the complete history, (not the shrunken version you see with C<H>),
3038 and saves it to the given filename, so it can be replayed using C<source>.
3040 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3042 =head4 C<R> - restart
3044 Restart the debugger session.
3046 =head4 C<rerun> - rerun the current session
3048 Return to any given position in the B<true>-history list
3050 =head4 C<|, ||> - pipe output through the pager.
3052 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3053 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3054 pipe to the pager (restoring the output filehandles if this fails). If this
3055 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3056 set C<$signal>, sending us back into the debugger.
3058 We then trim off the pipe symbols and C<redo> the command loop at the
3059 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3064 # || - run command in the pager, with output to DB::OUT.
3065 _DB__handle_run_command_in_pager_command($obj);
3067 =head3 END OF COMMAND PARSING
3069 Anything left in C<$cmd> at this point is a Perl expression that we want to
3070 evaluate. We'll always evaluate in the user's context, and fully qualify
3071 any variables we might want to address in the C<DB> package.
3077 # trace an expression
3078 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3080 # Make sure the flag that says "the debugger's running" is
3081 # still on, to make sure we get control again.
3082 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3084 # Run *our* eval that executes in the caller's context.
3087 # Turn off the one-time-dump stuff now.
3089 $onetimeDump = undef;
3090 $onetimedumpDepth = undef;
3092 elsif ( $term_pid == $$ ) {
3093 eval { # May run under miniperl, when not available...
3098 # XXX If this is the master pid, print a newline.
3101 } ## end while (($term || &setterm...
3103 =head3 POST-COMMAND PROCESSING
3105 After each command, we check to see if the command output was piped anywhere.
3106 If so, we go through the necessary code to unhook the pipe and go back to
3107 our standard filehandles for input and output.
3112 _DB__at_end_of_every_command($obj);
3115 =head3 COMMAND LOOP TERMINATION
3117 When commands have finished executing, we come here. If the user closed the
3118 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3119 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3120 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3121 The interpreter will then execute the next line and then return control to us
3126 # No more commands? Quit.
3127 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
3129 # Evaluate post-prompt commands.
3130 foreach $evalarg (@$post) {
3133 } # if ($single || $signal)
3135 # Put the user's globals back where you found them.
3136 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3140 # Because DB::Obj is used above,
3142 # my $obj = DB::Obj->new(
3144 # The following package declaraton must come before that,
3145 # or else runtime errors will occur with
3147 # PERLDB_OPTS="autotrace nonstop"
3157 my $self = bless {}, $class;
3165 my ($self, $args) = @_;
3167 %{$self} = (%$self, %$args);
3174 foreach my $slot_name (qw(
3175 after explicit_stop infix pat piped position prefix selected cmd_verb
3178 my $slot = $slot_name;
3183 ${ $self->{$slot} } = shift;
3186 return ${ $self->{$slot} };
3189 *{"append_to_$slot"} = sub {
3193 return $self->$slot($self->$slot . $s);
3198 sub _DB_on_init__initialize_globals
3202 # Check for whether we should be running continuously or not.
3203 # _After_ the perl program is compiled, $single is set to 1:
3204 if ( $single and not $second_time++ ) {
3206 # Options say run non-stop. Run until we get an interrupt.
3207 if ($runnonstop) { # Disable until signal
3208 # If there's any call stack in place, turn off single
3209 # stepping into subs throughout the stack.
3210 for my $i (0 .. $stack_depth) {
3214 # And we are now no longer in single-step mode.
3217 # If we simply returned at this point, we wouldn't get
3218 # the trace info. Fall on through.
3220 } ## end if ($runnonstop)
3222 elsif ($ImmediateStop) {
3224 # We are supposed to stop here; XXX probably a break.
3225 $ImmediateStop = 0; # We've processed it; turn it off
3226 $signal = 1; # Simulate an interrupt to force
3227 # us into the command loop
3229 } ## end if ($single and not $second_time...
3231 # If we're in single-step mode, or an interrupt (real or fake)
3232 # has occurred, turn off non-stop mode.
3233 $runnonstop = 0 if $single or $signal;
3238 sub _my_print_lineinfo
3240 my ($self, $i, $incr_pos) = @_;
3243 # Print it indented if tracing is on.
3244 DB::print_lineinfo( ' ' x $stack_depth,
3245 "$i:\t$DB::dbline[$i]" . $self->after );
3248 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3253 return $DB::dbline[$line];
3257 my ($self, $letter) = @_;
3259 return ($DB::cmd eq $letter);
3262 sub _DB__grab_control
3266 # Yes, grab control.
3267 if ($slave_editor) {
3269 # Tell the editor to update its position.
3270 $self->position("\032\032${DB::filename}:$line:0\n");
3271 DB::print_lineinfo($self->position());
3276 Special check: if we're in package C<DB::fake>, we've gone through the
3277 C<END> block at least once. We set up everything so that we can continue
3278 to enter commands and have a valid context to be in.
3282 elsif ( $DB::package eq 'DB::fake' ) {
3284 # Fallen off the end already.
3289 DB::print_help(<<EOP);
3290 Debugged program terminated. Use B<q> to quit or B<R> to restart,
3291 use B<o> I<inhibit_exit> to avoid stopping after program termination,
3292 B<h q>, B<h R> or B<h o> to get additional info.
3295 # Set the DB::eval context appropriately.
3296 $DB::package = 'main';
3297 $DB::usercontext = DB::_calc_usercontext($DB::package);
3298 } ## end elsif ($package eq 'DB::fake')
3302 If the program hasn't finished executing, we scan forward to the
3303 next executable line, print that out, build the prompt from the file and line
3304 number information, and print that.
3311 # Still somewhere in the midst of execution. Set up the
3313 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3314 # Perl 5 ones (sorry, we don't print Klingon
3317 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
3318 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
3319 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
3321 # Break up the prompt if it's really long.
3322 if ( length($self->prefix()) > 30 ) {
3323 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
3325 $self->infix(":\t");
3328 $self->infix("):\t");
3330 $self->prefix . $line. $self->infix
3331 . $self->_curr_line . $self->after
3335 # Print current line info, indenting if necessary.
3336 $self->_my_print_lineinfo($line, $self->position);
3339 my $line_i = sub { return $DB::dbline[$i]; };
3341 # Scan forward, stopping at either the end or the next
3343 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
3346 # Drop out on null statements, block closers, and comments.
3347 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
3349 # Drop out if the user interrupted us.
3352 # Append a newline if the line doesn't have one. Can happen
3353 # in eval'ed text, for instance.
3354 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
3356 # Next executable line.
3357 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
3359 $self->append_to_position($incr_pos);
3360 $self->_my_print_lineinfo($i, $incr_pos);
3361 } ## end for ($i = $line + 1 ; $i...
3362 } ## end else [ if ($slave_editor)
3367 sub _handle_t_command {
3370 my $levels = $self->cmd_args();
3372 if ((!length($levels)) or ($levels !~ /\D/)) {
3375 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3376 print {$OUT} "Trace = "
3378 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3387 sub _handle_S_command {
3390 if (my ($print_all_subs, $should_reverse, $Spatt)
3391 = $self->cmd_args =~ /\A((!)?(.+))?\z/) {
3392 # $Spatt is the pattern (if any) to use.
3394 my $Srev = defined $should_reverse;
3395 # No args - print all subs.
3396 my $Snocheck = !defined $print_all_subs;
3398 # Need to make these sane here.
3402 # Search through the debugger's magical hash of subs.
3403 # If $nocheck is true, just print the sub name.
3404 # Otherwise, check it against the pattern. We then use
3405 # the XOR trick to reverse the condition as required.
3406 foreach $subname ( sort( keys %sub ) ) {
3407 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3408 print $OUT $subname, "\n";
3417 sub _handle_V_command_and_X_command {
3420 $DB::cmd =~ s/^X\b/V $DB::package/;
3422 # Bare V commands get the currently-being-debugged package
3424 if ($self->_is_full('V')) {
3425 $DB::cmd = "V $DB::package";
3428 # V - show variables in package.
3429 if (my ($new_packname, $new_vars_str) =
3430 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3432 # Save the currently selected filehandle and
3433 # force output to debugger's filehandle (dumpvar
3434 # just does "print" for output).
3435 my $savout = select($OUT);
3437 # Grab package name and variables to dump.
3438 $packname = $new_packname;
3439 my @vars = split( ' ', $new_vars_str );
3441 # If main::dumpvar isn't here, get it.
3442 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3443 if ( defined &main::dumpvar ) {
3445 # We got it. Turn off subroutine entry/exit messages
3446 # for the moment, along with return values.
3450 # must detect sigpipe failures - not catching
3451 # then will cause the debugger to die.
3455 defined $option{dumpDepth}
3456 ? $option{dumpDepth}
3457 : -1, # assume -1 unless specified
3462 # The die doesn't need to include the $@, because
3463 # it will automatically get propagated for us.
3465 die unless $@ =~ /dumpvar print failed/;
3467 } ## end if (defined &main::dumpvar)
3470 # Couldn't load dumpvar.
3471 print $OUT "dumpvar.pl not available.\n";
3474 # Restore the output filehandle, and go round again.
3482 sub _handle_dash_command {
3485 if ($self->_is_full('-')) {
3487 # back up by a window; go to 1 if back too far.
3488 $start -= $incr + $window + 1;
3489 $start = 1 if $start <= 0;
3490 $incr = $window - 1;
3492 # Generate and execute a "l +" command (handled below).
3493 $DB::cmd = 'l ' . ($start) . '+';
3499 sub _n_or_s_commands_generic {
3500 my ($self, $new_val) = @_;
3502 next CMD if DB::_DB__is_finished();
3504 # Single step, but don't enter subs.
3507 # Save for empty command (repeat last).
3508 $laststep = $DB::cmd;
3513 my ($self, $letter, $new_val) = @_;
3515 if ($self->_is_full($letter)) {
3516 $self->_n_or_s_commands_generic($new_val);
3519 $self->_n_or_s_and_arg_commands_generic($letter, $new_val);
3525 sub _handle_n_command {
3528 return $self->_n_or_s('n', 2);
3531 sub _handle_s_command {
3534 return $self->_n_or_s('s', 1);
3537 sub _handle_r_command {
3540 # r - return from the current subroutine.
3541 if ($self->_is_full('r')) {
3543 # Can't do anything if the program's over.
3544 next CMD if DB::_DB__is_finished();
3546 # Turn on stack trace.
3547 $stack[$stack_depth] |= 1;
3549 # Print return value unless the stack is empty.
3550 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3557 sub _handle_T_command {
3560 if ($self->_is_full('T')) {
3561 DB::print_trace( $OUT, 1 ); # skip DB
3568 sub _handle_w_command {
3571 DB::cmd_w( 'w', $self->cmd_args() );
3577 sub _handle_W_command {
3580 if (my $arg = $self->cmd_args) {
3581 DB::cmd_W( 'W', $arg );
3588 sub _handle_rc_recall_command {
3591 # $rc - recall command.
3592 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3594 # No arguments, take one thing off history.
3595 pop(@hist) if length($DB::cmd) > 1;
3597 # Relative (- found)?
3598 # Y - index back from most recent (by 1 if bare minus)
3599 # N - go to that particular command slot or the last
3600 # thing if nothing following.
3603 scalar($minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist ))
3606 # Pick out the command desired.
3607 $DB::cmd = $hist[$self->cmd_verb];
3609 # Print the command to be executed and restart the loop
3610 # with that command in the buffer.
3611 print {$OUT} $DB::cmd, "\n";
3618 sub _handle_rc_search_history_command {
3621 # $rc pattern $rc - find a command in the history.
3622 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) {
3624 # Create the pattern to use.
3628 # Toss off last entry if length is >1 (and it always is).
3629 pop(@hist) if length($DB::cmd) > 1;
3633 # Look backward through the history.
3635 for ( $i = $#hist ; $i ; --$i ) {
3636 # Stop if we find it.
3637 last SEARCH_HIST if $hist[$i] =~ /$pat/;
3643 print $OUT "No such command!\n\n";
3647 # Found it. Put it in the buffer, print it, and process it.
3648 $DB::cmd = $hist[$i];
3649 print $OUT $DB::cmd, "\n";
3656 sub _handle_H_command {
3659 if ($self->cmd_args =~ m#\A\*#) {
3660 @hist = @truehist = ();
3661 print $OUT "History cleansed\n";
3665 if (my ($num) = $self->cmd_args =~ /\A(?:-(\d+))?/) {
3667 # Anything other than negative numbers is ignored by
3668 # the (incorrect) pattern, so this test does nothing.
3669 $end = $num ? ( $#hist - $num ) : 0;
3671 # Set to the minimum if less than zero.
3672 $hist = 0 if $hist < 0;
3674 # Start at the end of the array.
3675 # Stay in while we're still above the ending value.
3676 # Tick back by one each time around the loop.
3679 for ( $i = $#hist ; $i > $end ; $i-- ) {
3681 # Print the command unless it has no arguments.
3682 print $OUT "$i: ", $hist[$i], "\n"
3683 unless $hist[$i] =~ /^.?$/;
3692 sub _handle_doc_command {
3695 # man, perldoc, doc - show manual pages.
3697 = $DB::cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
3705 sub _handle_p_command {
3708 my $print_cmd = 'print {$DB::OUT} ';
3709 # p - print (no args): print $_.
3710 if ($self->_is_full('p')) {
3711 $DB::cmd = $print_cmd . '$_';
3714 # p - print the given expression.
3715 $DB::cmd =~ s/\Ap\b/$print_cmd /;
3721 sub _handle_equal_sign_command {
3724 if ($DB::cmd =~ s/\A=\s*//) {
3726 if ( length $DB::cmd == 0 ) {
3728 # No args, get current aliases.
3729 @keys = sort keys %alias;
3731 elsif ( my ( $k, $v ) = ( $DB::cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3733 # Creating a new alias. $k is alias name, $v is
3736 # can't use $_ or kill //g state
3737 for my $x ( $k, $v ) {
3739 # Escape "alarm" characters.
3743 # Substitute key for value, using alarm chars
3744 # as separators (which is why we escaped them in
3746 $alias{$k} = "s\a$k\a$v\a";
3748 # Turn off standard warn and die behavior.
3749 local $SIG{__DIE__};
3750 local $SIG{__WARN__};
3753 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3755 # Nope. Bad alias. Say so and get out.
3756 print $OUT "Can't alias $k to $v: $@\n";
3761 # We'll only list the new one.
3763 } ## end elsif (my ($k, $v) = ($DB::cmd...
3765 # The argument is the alias to list.
3773 # Messy metaquoting: Trim the substitution code off.
3774 # We use control-G as the delimiter because it's not
3775 # likely to appear in the alias.
3776 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3779 print $OUT "$k\t= $1\n";
3781 elsif ( defined $alias{$k} ) {
3783 # Couldn't trim it off; just print the alias code.
3784 print $OUT "$k\t$alias{$k}\n";
3789 print "No alias for $k\n";
3791 } ## end for my $k (@keys)
3798 sub _handle_source_command {
3801 # source - read commands from a file (or pipe!) and execute.
3802 if (my $sourced_fn = $self->cmd_args) {
3803 if ( open my $fh, $sourced_fn ) {
3805 # Opened OK; stick it in the list of file handles.
3811 DB::_db_warn("Can't execute '$sourced_fn': $!\n");
3819 sub _handle_enable_disable_commands {
3822 my $which_cmd = $self->cmd_verb;
3823 my $position = $self->cmd_args;
3825 if ($position !~ /\s/) {
3826 my ($fn, $line_num);
3827 if ($position =~ m{\A\d+\z})
3829 $fn = $DB::filename;
3830 $line_num = $position;
3832 elsif (my ($new_fn, $new_line_num)
3833 = $position =~ m{\A(.*):(\d+)\z}) {
3834 ($fn, $line_num) = ($new_fn, $new_line_num);
3838 DB::_db_warn("Wrong spec for enable/disable argument.\n");
3842 if (DB::_has_breakpoint_data_ref($fn, $line_num)) {
3843 DB::_set_breakpoint_enabled_status($fn, $line_num,
3844 ($which_cmd eq 'enable' ? 1 : '')
3848 DB::_db_warn("No breakpoint set at ${fn}:${line_num}\n");
3858 sub _handle_save_command {
3861 if (my $new_fn = $self->cmd_args) {
3862 my $filename = $new_fn || '.perl5dbrc'; # default?
3863 if ( open my $fh, '>', $filename ) {
3865 # chomp to remove extraneous newlines from source'd files
3866 chomp( my @truelist =
3867 map { m/\A\s*(save|source)/ ? "#$_" : $_ }
3869 print {$fh} join( "\n", @truelist );
3870 print "commands saved in $filename\n";
3873 DB::_db_warn("Can't save debugger commands in '$new_fn': $!\n");
3881 sub _n_or_s_and_arg_commands_generic {
3882 my ($self, $letter, $new_val) = @_;
3884 # s - single-step. Remember the last command was 's'.
3885 if ($DB::cmd =~ s#\A\Q$letter\E\s#\$DB::single = $new_val;\n#) {
3886 $laststep = $letter;
3892 sub _handle_sh_command {
3895 # $sh$sh - run a shell command (if it's all ASCII).
3896 # Can't run shell commands with Unicode in the debugger, hmm.
3897 my $my_cmd = $DB::cmd;
3898 if ($my_cmd =~ m#\A$sh#gms) {
3900 if ($my_cmd =~ m#\G\z#cgms) {
3901 # Run the user's shell. If none defined, run Bourne.
3902 # We resume execution when the shell terminates.
3903 DB::_db_system( $ENV{SHELL} || "/bin/sh" );
3906 elsif ($my_cmd =~ m#\G$sh\s*(.*)#cgms) {
3911 elsif ($my_cmd =~ m#\G\s*(.*)#cgms) {
3912 DB::_db_system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3918 sub _handle_x_command {
3921 if ($DB::cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
3922 $onetimeDump = 'dump'; # main::dumpvar shows the output
3924 # handle special "x 3 blah" syntax XXX propagate
3925 # doc back to special variables.
3926 if ( $DB::cmd =~ s#\A\s*(\d+)(?=\s)# #) {
3927 $onetimedumpDepth = $1;
3934 sub _handle_q_command {
3937 if ($self->_is_full('q')) {
3946 sub _handle_cmd_wrapper_commands {
3949 DB::cmd_wrapper( $self->cmd_verb, $self->cmd_args, $line );
3953 sub _handle_special_char_cmd_wrapper_commands {
3956 # All of these commands were remapped in perl 5.8.0;
3957 # we send them off to the secondary dispatcher (see below).
3958 if (my ($cmd_letter, $my_arg) = $DB::cmd =~ /\A([<>\{]{1,2})\s*(.*)/so) {
3959 DB::cmd_wrapper( $cmd_letter, $my_arg, $line );
3970 # The following code may be executed now:
3975 C<sub> is called whenever a subroutine call happens in the program being
3976 debugged. The variable C<$DB::sub> contains the name of the subroutine
3979 The core function of this subroutine is to actually call the sub in the proper
3980 context, capturing its output. This of course causes C<DB::DB> to get called
3981 again, repeating until the subroutine ends and returns control to C<DB::sub>
3982 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3983 return value, and returns its captured copy of the return value as its own
3984 return value. The value then feeds back into the program being debugged as if
3985 C<DB::sub> hadn't been there at all.
3987 C<sub> does all the work of printing the subroutine entry and exit messages
3988 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3989 and also prints the return value if needed (for the C<r> command and if
3990 the 16 bit is set in C<$frame>).
3992 It also tracks the subroutine call depth by saving the current setting of
3993 C<$single> in the C<@stack> package global; if this exceeds the value in
3994 C<$deep>, C<sub> automatically turns on printing of the current depth by
3995 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
3996 of stop/don't stop on entry to subs set as it currently is set.
3998 =head3 C<caller()> support
4000 If C<caller()> is called from the package C<DB>, it provides some
4001 additional data, in the following order:
4007 The package name the sub was in
4009 =item * C<$filename>
4011 The filename it was defined in
4015 The line number it was defined on
4017 =item * C<$subroutine>
4019 The subroutine name; C<(eval)> if an C<eval>().
4023 1 if it has arguments, 0 if not
4025 =item * C<$wantarray>
4027 1 if array context, 0 if scalar context
4029 =item * C<$evaltext>
4031 The C<eval>() text, if any (undefined for C<eval BLOCK>)
4033 =item * C<$is_require>
4035 frame was created by a C<use> or C<require> statement
4039 pragma information; subject to change between versions
4043 pragma information; subject to change between versions
4045 =item * C<@DB::args>
4047 arguments with which the subroutine was invoked
4055 # We need to fully qualify the name ("DB::sub") to make "use strict;"
4056 # happy. -- Shlomi Fish
4058 sub _indent_print_line_info {
4059 my ($offset, $str) = @_;
4061 print_lineinfo( ' ' x ($stack_depth - $offset), $str);
4066 sub _print_frame_message {
4070 if ($frame & 4) { # Extended frame entry message
4071 _indent_print_line_info(-1, "in ");
4073 # Why -1? But it works! :-(
4074 # Because print_trace will call add 1 to it and then call
4075 # dump_trace; this results in our skipping -1+1 = 0 stack frames
4078 # Now it's 0 because we extracted a function.
4079 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" );
4082 _indent_print_line_info(-1, "entering $sub$al\n" );
4090 # Do not use a regex in this subroutine -> results in corrupted memory
4091 # See: [perl #66110]
4093 # lock ourselves under threads
4096 # Whether or not the autoloader was running, a scalar to put the
4097 # sub's return value in (if needed), and an array to put the sub's
4098 # return value in (if needed).
4099 my ( $al, $ret, @ret ) = "";
4100 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
4101 print "creating new thread\n";
4104 # If the last ten characters are '::AUTOLOAD', note we've traced
4105 # into AUTOLOAD for $sub.
4106 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4108 $al = " for $$sub" if defined $$sub;
4111 # We stack the stack pointer and then increment it to protect us
4112 # from a situation that might unwind a whole bunch of call frames
4113 # at once. Localizing the stack pointer means that it will automatically
4114 # unwind the same amount when multiple stack frames are unwound.
4115 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4118 $#stack = $stack_depth;
4120 # Save current single-step setting.
4121 $stack[-1] = $single;
4123 # Turn off all flags except single-stepping.
4126 # If we've gotten really deeply recursed, turn on the flag that will
4127 # make us stop with the 'deep recursion' message.
4128 $single |= 4 if $stack_depth == $deep;
4130 # If frame messages are on ...
4132 _print_frame_message($al);
4133 # standard frame entry message
4135 my $print_exit_msg = sub {
4136 # Check for exit trace messages...
4139 if ($frame & 4) # Extended exit message
4141 _indent_print_line_info(0, "out ");
4142 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" );
4146 _indent_print_line_info(0, "exited $sub$al\n" );
4152 # Determine the sub's return type, and capture appropriately.
4155 # Called in array context. call sub and capture output.
4156 # DB::DB will recursively get control again if appropriate; we'll come
4157 # back here when the sub is finished.
4163 # Pop the single-step value back off the stack.
4164 $single |= $stack[ $stack_depth-- ];
4166 $print_exit_msg->();
4168 # Print the return info if we need to.
4169 if ( $doret eq $stack_depth or $frame & 16 ) {
4171 # Turn off output record separator.
4173 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4175 # Indent if we're printing because of $frame tracing.
4178 print {$fh} ' ' x $stack_depth;
4181 # Print the return value.
4182 print {$fh} "list context return from $sub:\n";
4183 dumpit( $fh, \@ret );
4185 # And don't print it again.
4187 } ## end if ($doret eq $stack_depth...
4188 # And we have to return the return value now.
4190 } ## end if (wantarray)
4194 if ( defined wantarray ) {
4196 # Save the value if it's wanted at all.
4201 # Void return, explicitly.
4206 # Pop the single-step value off the stack.
4207 $single |= $stack[ $stack_depth-- ];
4209 # If we're doing exit messages...
4210 $print_exit_msg->();
4212 # If we are supposed to show the return value... same as before.
4213 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
4215 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4216 print $fh ( ' ' x $stack_depth ) if $frame & 16;
4219 ? "scalar context return from $sub: "
4220 : "void context return from $sub\n"
4222 dumpit( $fh, $ret ) if defined wantarray;
4224 } ## end if ($doret eq $stack_depth...
4226 # Return the appropriate scalar value.
4228 } ## end else [ if (wantarray)
4235 # lock ourselves under threads
4238 # Whether or not the autoloader was running, a scalar to put the
4239 # sub's return value in (if needed), and an array to put the sub's
4240 # return value in (if needed).
4241 my ( $al, $ret, @ret ) = "";
4242 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
4243 print "creating new thread\n";
4246 # If the last ten characters are C'::AUTOLOAD', note we've traced
4247 # into AUTOLOAD for $sub.
4248 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4252 # We stack the stack pointer and then increment it to protect us
4253 # from a situation that might unwind a whole bunch of call frames
4254 # at once. Localizing the stack pointer means that it will automatically
4255 # unwind the same amount when multiple stack frames are unwound.
4256 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4259 $#stack = $stack_depth;
4261 # Save current single-step setting.
4262 $stack[-1] = $single;
4264 # Turn off all flags except single-stepping.
4267 # If we've gotten really deeply recursed, turn on the flag that will
4268 # make us stop with the 'deep recursion' message.
4269 $single |= 4 if $stack_depth == $deep;
4271 # If frame messages are on ...
4272 _print_frame_message($al);
4274 # Pop the single-step value back off the stack.
4275 $single |= $stack[ $stack_depth-- ];
4277 # call the original lvalue sub.
4281 # Abstracting common code from multiple places elsewhere:
4282 sub depth_print_lineinfo {
4283 my $always_print = shift;
4285 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth);
4288 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
4290 In Perl 5.8.0, there was a major realignment of the commands and what they did,
4291 Most of the changes were to systematize the command structure and to eliminate
4292 commands that threw away user input without checking.
4294 The following sections describe the code added to make it easy to support
4295 multiple command sets with conflicting command names. This section is a start
4296 at unifying all command processing to make it simpler to develop commands.
4298 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
4299 number, and C<$dbline> (the current line) as arguments.
4301 Support functions in this section which have multiple modes of failure C<die>
4302 on error; the rest simply return a false value.
4304 The user-interface functions (all of the C<cmd_*> functions) just output
4309 The C<%set> hash defines the mapping from command letter to subroutine
4312 C<%set> is a two-level hash, indexed by set name and then by command name.
4313 Note that trying to set the CommandSet to C<foobar> simply results in the
4314 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
4323 'A' => 'pre580_null',
4325 'B' => 'pre580_null',
4326 'd' => 'pre580_null',
4329 'M' => 'pre580_null',
4331 'o' => 'pre580_null',
4337 '<' => 'pre590_prepost',
4338 '<<' => 'pre590_prepost',
4339 '>' => 'pre590_prepost',
4340 '>>' => 'pre590_prepost',
4341 '{' => 'pre590_prepost',
4342 '{{' => 'pre590_prepost',
4346 my %breakpoints_data;
4348 sub _has_breakpoint_data_ref {
4349 my ($filename, $line) = @_;
4352 exists( $breakpoints_data{$filename} )
4354 exists( $breakpoints_data{$filename}{$line} )
4358 sub _get_breakpoint_data_ref {
4359 my ($filename, $line) = @_;
4361 return ($breakpoints_data{$filename}{$line} ||= +{});
4364 sub _delete_breakpoint_data_ref {
4365 my ($filename, $line) = @_;
4367 delete($breakpoints_data{$filename}{$line});
4368 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) {
4369 delete($breakpoints_data{$filename});
4375 sub _set_breakpoint_enabled_status {
4376 my ($filename, $line, $status) = @_;
4378 _get_breakpoint_data_ref($filename, $line)->{'enabled'} =
4385 sub _enable_breakpoint_temp_enabled_status {
4386 my ($filename, $line) = @_;
4388 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1;
4393 sub _cancel_breakpoint_temp_enabled_status {
4394 my ($filename, $line) = @_;
4396 my $ref = _get_breakpoint_data_ref($filename, $line);
4398 delete ($ref->{'temp_enabled'});
4401 _delete_breakpoint_data_ref($filename, $line);
4407 sub _is_breakpoint_enabled {
4408 my ($filename, $line) = @_;
4410 my $data_ref = _get_breakpoint_data_ref($filename, $line);
4411 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'});
4414 =head2 C<cmd_wrapper()> (API)
4416 C<cmd_wrapper()> allows the debugger to switch command sets
4417 depending on the value of the C<CommandSet> option.
4419 It tries to look up the command in the C<%set> package-level I<lexical>
4420 (which means external entities can't fiddle with it) and create the name of
4421 the sub to call based on the value found in the hash (if it's there). I<All>
4422 of the commands to be handled in a set have to be added to C<%set>; if they
4423 aren't found, the 5.8.0 equivalent is called (if there is one).
4425 This code uses symbolic references.
4432 my $dblineno = shift;
4434 # Assemble the command subroutine's name by looking up the
4435 # command set and command name in %set. If we can't find it,
4436 # default to the older version of the command.
4438 . ( $set{$CommandSet}{$cmd}
4439 || ( $cmd =~ /\A[<>{]+/o ? 'prepost' : $cmd ) );
4441 # Call the command subroutine, call it by name.
4442 return __PACKAGE__->can($call)->( $cmd, $line, $dblineno );
4443 } ## end sub cmd_wrapper
4445 =head3 C<cmd_a> (command)
4447 The C<a> command handles pre-execution actions. These are associated with a
4448 particular line, so they're stored in C<%dbline>. We default to the current
4449 line if none is specified.
4455 my $line = shift || ''; # [.|line] expr
4458 # If it's dot (here), or not all digits, use the current line.
4459 $line =~ s/\A\./$dbline/;
4461 # Should be a line number followed by an expression.
4462 if ( my ($lineno, $expr) = $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
4464 if (! length($lineno)) {
4468 # If we have an expression ...
4469 if ( length $expr ) {
4471 # ... but the line isn't breakable, complain.
4472 if ( $dbline[$lineno] == 0 ) {
4474 "Line $lineno($dbline[$lineno]) does not have an action?\n";
4478 # It's executable. Record that the line has an action.
4479 $had_breakpoints{$filename} |= 2;
4481 # Remove any action, temp breakpoint, etc.
4482 $dbline{$lineno} =~ s/\0[^\0]*//;
4484 # Add the action to the line.
4485 $dbline{$lineno} .= "\0" . action($expr);
4487 _set_breakpoint_enabled_status($filename, $lineno, 1);
4489 } ## end if (length $expr)
4490 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
4495 "Adding an action requires an optional lineno and an expression\n"
4500 =head3 C<cmd_A> (command)
4502 Delete actions. Similar to above, except the delete code is in a separate
4503 subroutine, C<delete_action>.
4509 my $line = shift || '';
4513 $line =~ s/^\./$dbline/;
4515 # Call delete_action with a null param to delete them all.
4516 # The '1' forces the eval to be true. It'll be false only
4517 # if delete_action blows up for some reason, in which case
4518 # we print $@ and get out.
4519 if ( $line eq '*' ) {
4520 if (! eval { _delete_all_actions(); 1 }) {
4526 # There's a real line number. Pass it to delete_action.
4527 # Error trapping is as above.
4528 elsif ( $line =~ /^(\S.*)/ ) {
4529 if (! eval { delete_action($1); 1 }) {
4535 # Swing and a miss. Bad syntax.
4538 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4542 =head3 C<delete_action> (API)
4544 C<delete_action> accepts either a line number or C<undef>. If a line number
4545 is specified, we check for the line being executable (if it's not, it
4546 couldn't have had an action). If it is, we just take the action off (this
4547 will get any kind of an action, including breakpoints).
4551 sub _remove_action_from_dbline {
4554 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4555 delete $dbline{$i} if $dbline{$i} eq '';
4560 sub _delete_all_actions {
4561 print {$OUT} "Deleting all actions...\n";
4563 for my $file ( keys %had_breakpoints ) {
4564 local *dbline = $main::{ '_<' . $file };
4567 for my $i (1 .. $max) {
4568 if ( defined $dbline{$i} ) {
4569 _remove_action_from_dbline($i);
4573 unless ( $had_breakpoints{$file} &= ~2 ) {
4574 delete $had_breakpoints{$file};
4584 if ( defined($i) ) {
4586 die "Line $i has no action .\n" if $dbline[$i] == 0;
4588 # Nuke whatever's there.
4589 _remove_action_from_dbline($i);
4592 _delete_all_actions();
4596 =head3 C<cmd_b> (command)
4598 Set breakpoints. Since breakpoints can be set in so many places, in so many
4599 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4600 we try to parse the command type, and then shuttle it off to an appropriate
4601 subroutine to actually do the work of setting the breakpoint in the right
4608 my $line = shift; # [.|line] [cond]
4611 my $default_cond = sub {
4613 return length($cond) ? $cond : '1';
4616 # Make . the current line number if it's there..
4617 $line =~ s/^\.(\s|\z)/$dbline$1/;
4619 # No line number, no condition. Simple break on current line.
4620 if ( $line =~ /^\s*$/ ) {
4621 cmd_b_line( $dbline, 1 );
4624 # Break on load for a file.
4625 elsif ( my ($file) = $line =~ /^load\b\s*(.*)/ ) {
4630 # b compile|postpone <some sub> [<condition>]
4631 # The interpreter actually traps this one for us; we just put the
4632 # necessary condition in the %postponed hash.
4633 elsif ( my ($action, $subname, $cond)
4634 = $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4636 # De-Perl4-ify the name - ' separators to ::.
4637 $subname =~ s/'/::/g;
4639 # Qualify it into the current package unless it's already qualified.
4640 $subname = "${package}::" . $subname unless $subname =~ /::/;
4642 # Add main if it starts with ::.
4643 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4645 # Save the break type for this sub.
4646 $postponed{$subname} = (($action eq 'postpone')
4647 ? ( "break +0 if " . $default_cond->($cond) )
4649 } ## end elsif ($line =~ ...
4650 # b <filename>:<line> [<condition>]
4651 elsif (my ($filename, $line_num, $cond)
4652 = $line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) {
4653 cmd_b_filename_line(
4656 (length($cond) ? $cond : '1'),
4659 # b <sub name> [<condition>]
4660 elsif ( my ($new_subname, $new_cond) =
4661 $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4664 $subname = $new_subname;
4665 cmd_b_sub( $subname, $default_cond->($new_cond) );
4668 # b <line> [<condition>].
4669 elsif ( my ($line_n, $cond) = $line =~ /^(\d*)\s*(.*)/ ) {
4671 # Capture the line. If none, it's the current line.
4672 $line = $line_n || $dbline;
4675 cmd_b_line( $line, $default_cond->($cond) );
4678 # Line didn't make sense.
4680 print "confused by line($line)?\n";
4686 =head3 C<break_on_load> (API)
4688 We want to break when this file is loaded. Mark this file in the
4689 C<%break_on_load> hash, and note that it has a breakpoint in
4690 C<%had_breakpoints>.
4696 $break_on_load{$file} = 1;
4697 $had_breakpoints{$file} |= 1;
4700 =head3 C<report_break_on_load> (API)
4702 Gives us an array of filenames that are set to break on load. Note that
4703 only files with break-on-load are in here, so simply showing the keys
4708 sub report_break_on_load {
4709 sort keys %break_on_load;
4712 =head3 C<cmd_b_load> (command)
4714 We take the file passed in and try to find it in C<%INC> (which maps modules
4715 to files they came from). We mark those files for break-on-load via
4716 C<break_on_load> and then report that it was done.
4724 # This is a block because that way we can use a redo inside it
4725 # even without there being any looping structure at all outside it.
4728 # Save short name and full path if found.
4730 push @files, $::INC{$file} if $::INC{$file};
4732 # Tack on .pm and do it again unless there was a '.' in the name
4734 $file .= '.pm', redo unless $file =~ /\./;
4737 # Do the real work here.
4738 break_on_load($_) for @files;
4740 # All the files that have break-on-load breakpoints.
4741 @files = report_break_on_load;
4743 # Normalize for the purposes of our printing this.
4746 print $OUT "Will stop on load of '@files'.\n";
4747 } ## end sub cmd_b_load
4749 =head3 C<$filename_error> (API package global)
4751 Several of the functions we need to implement in the API need to work both
4752 on the current file and on other files. We don't want to duplicate code, so
4753 C<$filename_error> is used to contain the name of the file that's being
4754 worked on (if it's not the current one).
4756 We can now build functions in pairs: the basic function works on the current
4757 file, and uses C<$filename_error> as part of its error message. Since this is
4758 initialized to C<"">, no filename will appear when we are working on the
4761 The second function is a wrapper which does the following:
4767 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4771 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4775 Calls the first function.
4777 The first function works on the I<current> file (i.e., the one we changed to),
4778 and prints C<$filename_error> in the error message (the name of the other file)
4779 if it needs to. When the functions return, C<*dbline> is restored to point
4780 to the actual current file (the one we're executing in) and
4781 C<$filename_error> is restored to C<"">. This restores everything to
4782 the way it was before the second function was called at all.
4784 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4791 use vars qw($filename_error);
4792 $filename_error = '';
4794 =head3 breakable_line(from, to) (API)
4796 The subroutine decides whether or not a line in the current file is breakable.
4797 It walks through C<@dbline> within the range of lines specified, looking for
4798 the first line that is breakable.
4800 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4801 first line I<after> C<$to> that's breakable, if there is one.
4803 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4804 first line I<before> C<$to> that's breakable, if there is one.
4808 sub breakable_line {
4810 my ( $from, $to ) = @_;
4812 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4815 # If there are at least 2 arguments, we're trying to search a range.
4818 # $delta is positive for a forward search, negative for a backward one.
4819 my $delta = $from < $to ? +1 : -1;
4821 # Keep us from running off the ends of the file.
4822 my $limit = $delta > 0 ? $#dbline : 1;
4824 # Clever test. If you're a mathematician, it's obvious why this
4825 # test works. If not:
4826 # If $delta is positive (going forward), $limit will be $#dbline.
4827 # If $to is less than $limit, ($limit - $to) will be positive, times
4828 # $delta of 1 (positive), so the result is > 0 and we should use $to
4829 # as the stopping point.
4831 # If $to is greater than $limit, ($limit - $to) is negative,
4832 # times $delta of 1 (positive), so the result is < 0 and we should
4833 # use $limit ($#dbline) as the stopping point.
4835 # If $delta is negative (going backward), $limit will be 1.
4836 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4837 # (negative) so the result is > 0, and we use $to as the stopping
4840 # If $to is less than zero, ($limit - $to) will be positive,
4841 # times $delta of -1 (negative), so the result is not > 0, and
4842 # we use $limit (1) as the stopping point.
4844 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4845 # (negative), still giving zero; the result is not > 0, and
4846 # we use $limit (1) as the stopping point.
4848 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4849 # (negative), giving a positive (>0) value, so we'll set $limit to
4852 $limit = $to if ( $limit - $to ) * $delta > 0;
4854 # The real search loop.
4855 # $i starts at $from (the point we want to start searching from).
4856 # We move through @dbline in the appropriate direction (determined
4857 # by $delta: either -1 (back) or +1 (ahead).
4858 # We stay in as long as we haven't hit an executable line
4859 # ($dbline[$i] == 0 means not executable) and we haven't reached
4860 # the limit yet (test similar to the above).
4861 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4863 } ## end if (@_ >= 2)
4865 # If $i points to a line that is executable, return that.
4866 return $i unless $dbline[$i] == 0;
4868 # Format the message and print it: no breakable lines in range.
4869 my ( $pl, $upto ) = ( '', '' );
4870 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4872 # If there's a filename in filename_error, we'll see it.
4874 die "Line$pl $from$upto$filename_error not breakable\n";
4875 } ## end sub breakable_line
4877 =head3 breakable_line_in_filename(file, from, to) (API)
4879 Like C<breakable_line>, but look in another file.
4883 sub breakable_line_in_filename {
4885 # Capture the file name.
4888 # Swap the magic line array over there temporarily.
4889 local *dbline = $main::{ '_<' . $f };
4891 # If there's an error, it's in this other file.
4892 local $filename_error = " of '$f'";
4894 # Find the breakable line.
4897 # *dbline and $filename_error get restored when this block ends.
4899 } ## end sub breakable_line_in_filename
4901 =head3 break_on_line(lineno, [condition]) (API)
4903 Adds a breakpoint with the specified condition (or 1 if no condition was
4904 specified) to the specified line. Dies if it can't.
4910 my $cond = @_ ? shift(@_) : 1;
4916 # Woops, not a breakable line. $filename_error allows us to say
4917 # if it was in a different file.
4918 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4920 # Mark this file as having breakpoints in it.
4921 $had_breakpoints{$filename} |= 1;
4923 # If there is an action or condition here already ...
4924 if ( $dbline{$i} ) {
4926 # ... swap this condition for the existing one.
4927 $dbline{$i} =~ s/^[^\0]*/$cond/;
4931 # Nothing here - just add the condition.
4932 $dbline{$i} = $cond;
4934 _set_breakpoint_enabled_status($filename, $i, 1);
4938 } ## end sub break_on_line
4940 =head3 cmd_b_line(line, [condition]) (command)
4942 Wrapper for C<break_on_line>. Prints the failure message if it
4948 if (not eval { break_on_line(@_); 1 }) {
4950 print $OUT $@ and return;
4954 } ## end sub cmd_b_line
4956 =head3 cmd_b_filename_line(line, [condition]) (command)
4958 Wrapper for C<break_on_filename_line>. Prints the failure message if it
4963 sub cmd_b_filename_line {
4964 if (not eval { break_on_filename_line(@_); 1 }) {
4966 print $OUT $@ and return;
4972 =head3 break_on_filename_line(file, line, [condition]) (API)
4974 Switches to the file specified and then calls C<break_on_line> to set
4979 sub break_on_filename_line {
4982 my $cond = @_ ? shift(@_) : 1;
4984 # Switch the magical hash temporarily.
4985 local *dbline = $main::{ '_<' . $f };
4987 # Localize the variables that break_on_line uses to make its message.
4988 local $filename_error = " of '$f'";
4989 local $filename = $f;
4991 # Add the breakpoint.
4992 break_on_line( $i, $cond );
4995 } ## end sub break_on_filename_line
4997 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4999 Switch to another file, search the range of lines specified for an
5000 executable one, and put a breakpoint on the first one you find.
5004 sub break_on_filename_line_range {
5008 my $cond = @_ ? shift(@_) : 1;
5010 # Find a breakable line if there is one.
5011 my $i = breakable_line_in_filename( $f, $from, $to );
5013 # Add the breakpoint.
5014 break_on_filename_line( $f, $i, $cond );
5017 } ## end sub break_on_filename_line_range
5019 =head3 subroutine_filename_lines(subname, [condition]) (API)
5021 Search for a subroutine within a given file. The condition is ignored.
5022 Uses C<find_sub> to locate the desired subroutine.
5026 sub subroutine_filename_lines {
5027 my ( $subname ) = @_;
5029 # Returned value from find_sub() is fullpathname:startline-endline.
5030 # The match creates the list (fullpathname, start, end).
5031 return (find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/);
5032 } ## end sub subroutine_filename_lines
5034 =head3 break_subroutine(subname) (API)
5036 Places a break on the first line possible in the specified subroutine. Uses
5037 C<subroutine_filename_lines> to find the subroutine, and
5038 C<break_on_filename_line_range> to place the break.
5042 sub break_subroutine {
5043 my $subname = shift;
5045 # Get filename, start, and end.
5046 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
5047 or die "Subroutine $subname not found.\n";
5050 # Null condition changes to '1' (always true).
5051 my $cond = @_ ? shift(@_) : 1;
5053 # Put a break the first place possible in the range of lines
5054 # that make up this subroutine.
5055 break_on_filename_line_range( $file, $s, $e, $cond );
5058 } ## end sub break_subroutine
5060 =head3 cmd_b_sub(subname, [condition]) (command)
5062 We take the incoming subroutine name and fully-qualify it as best we can.
5066 =item 1. If it's already fully-qualified, leave it alone.
5068 =item 2. Try putting it in the current package.
5070 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
5072 =item 4. If it starts with '::', put it in 'main::'.
5076 After all this cleanup, we call C<break_subroutine> to try to set the
5082 my $subname = shift;
5083 my $cond = @_ ? shift : 1;
5085 # If the subname isn't a code reference, qualify it so that
5086 # break_subroutine() will work right.
5087 if ( ref($subname) ne 'CODE' ) {
5090 $subname =~ s/'/::/g;
5093 # Put it in this package unless it's already qualified.
5094 if ($subname !~ /::/)
5096 $subname = $package . '::' . $subname;
5099 # Requalify it into CORE::GLOBAL if qualifying it into this
5100 # package resulted in its not being defined, but only do so
5101 # if it really is in CORE::GLOBAL.
5102 my $core_name = "CORE::GLOBAL::$s";
5103 if ((!defined(&$subname))
5105 and (defined &{$core_name}))
5107 $subname = $core_name;
5110 # Put it in package 'main' if it has a leading ::.
5111 if ($subname =~ /\A::/)
5113 $subname = "main" . $subname;
5115 } ## end if ( ref($subname) ne 'CODE' ) {
5117 # Try to set the breakpoint.
5118 if (not eval { break_subroutine( $subname, $cond ); 1 }) {
5125 } ## end sub cmd_b_sub
5127 =head3 C<cmd_B> - delete breakpoint(s) (command)
5129 The command mostly parses the command line and tries to turn the argument
5130 into a line spec. If it can't, it uses the current line. It then calls
5131 C<delete_breakpoint> to actually do the work.
5133 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
5134 thereby deleting all the breakpoints.
5141 # No line spec? Use dbline.
5142 # If there is one, use it if it's non-zero, or wipe it out if it is.
5143 my $line = ( $_[0] =~ /\A\./ ) ? $dbline : (shift || '');
5146 # If the line was dot, make the line the current one.
5147 $line =~ s/^\./$dbline/;
5149 # If it's * we're deleting all the breakpoints.
5150 if ( $line eq '*' ) {
5151 if (not eval { delete_breakpoint(); 1 }) {
5156 # If there is a line spec, delete the breakpoint on that line.
5157 elsif ( $line =~ /\A(\S.*)/ ) {
5158 if (not eval { delete_breakpoint( $line || $dbline ); 1 }) {
5162 } ## end elsif ($line =~ /^(\S.*)/)
5167 "Deleting a breakpoint requires a line number, or '*' for all\n"
5174 =head3 delete_breakpoint([line]) (API)
5176 This actually does the work of deleting either a single breakpoint, or all
5179 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
5180 just drop out with a message saying so. If it is, we remove the condition
5181 part of the 'condition\0action' that says there's a breakpoint here. If,
5182 after we've done that, there's nothing left, we delete the corresponding
5183 line in C<%dbline> to signal that no action needs to be taken for this line.
5185 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
5186 which lists all currently-loaded files which have breakpoints. We then look
5187 at each line in each of these files, temporarily switching the C<%dbline>
5188 and C<@dbline> structures to point to the files in question, and do what
5189 we did in the single line case: delete the condition in C<@dbline>, and
5190 delete the key in C<%dbline> if nothing's left.
5192 We then wholesale delete C<%postponed>, C<%postponed_file>, and
5193 C<%break_on_load>, because these structures contain breakpoints for files
5194 and code that haven't been loaded yet. We can just kill these off because there
5195 are no magical debugger structures associated with them.
5199 sub _remove_breakpoint_entry {
5203 _delete_breakpoint_data_ref($fn, $i);
5208 sub _delete_all_breakpoints {
5209 print {$OUT} "Deleting all breakpoints...\n";
5211 # %had_breakpoints lists every file that had at least one
5213 for my $fn ( keys %had_breakpoints ) {
5215 # Switch to the desired file temporarily.
5216 local *dbline = $main::{ '_<' . $fn };
5220 # For all lines in this file ...
5221 for my $i (1 .. $max) {
5223 # If there's a breakpoint or action on this line ...
5224 if ( defined $dbline{$i} ) {
5226 # ... remove the breakpoint.
5227 $dbline{$i} =~ s/\A[^\0]+//;
5228 if ( $dbline{$i} =~ s/\A\0?\z// ) {
5229 # Remove the entry altogether if no action is there.
5230 _remove_breakpoint_entry($fn, $i);
5232 } ## end if (defined $dbline{$i...
5233 } ## end for $i (1 .. $max)
5235 # If, after we turn off the "there were breakpoints in this file"
5236 # bit, the entry in %had_breakpoints for this file is zero,
5237 # we should remove this file from the hash.
5238 if ( not $had_breakpoints{$fn} &= (~1) ) {
5239 delete $had_breakpoints{$fn};
5241 } ## end for my $fn (keys %had_breakpoints)
5243 # Kill off all the other breakpoints that are waiting for files that
5244 # haven't been loaded yet.
5246 undef %postponed_file;
5247 undef %break_on_load;
5252 sub _delete_breakpoint_from_line {
5255 # Woops. This line wasn't breakable at all.
5256 die "Line $i not breakable.\n" if $dbline[$i] == 0;
5258 # Kill the condition, but leave any action.
5259 $dbline{$i} =~ s/\A[^\0]*//;
5261 # Remove the entry entirely if there's no action left.
5262 if ($dbline{$i} eq '') {
5263 _remove_breakpoint_entry($filename, $i);
5269 sub delete_breakpoint {
5272 # If we got a line, delete just that one.
5273 if ( defined($i) ) {
5274 _delete_breakpoint_from_line($i);
5276 # No line; delete them all.
5278 _delete_all_breakpoints();
5284 =head3 cmd_stop (command)
5286 This is meant to be part of the new command API, but it isn't called or used
5287 anywhere else in the debugger. XXX It is probably meant for use in development
5292 sub cmd_stop { # As on ^C, but not signal-safy.
5296 =head3 C<cmd_e> - threads
5298 Display the current thread id:
5302 This could be how (when implemented) to send commands to this thread id (e cmd)
5303 or that thread id (e tid cmd).
5310 unless (exists($INC{'threads.pm'})) {
5311 print "threads not loaded($ENV{PERL5DB_THREADED})
5312 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5314 my $tid = threads->tid;
5315 print "thread id: $tid\n";
5319 =head3 C<cmd_E> - list of thread ids
5321 Display the list of available thread ids:
5325 This could be used (when implemented) to send commands to all threads (E cmd).
5332 unless (exists($INC{'threads.pm'})) {
5333 print "threads not loaded($ENV{PERL5DB_THREADED})
5334 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5336 my $tid = threads->tid;
5337 print "thread ids: ".join(', ',
5338 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
5343 =head3 C<cmd_h> - help command (command)
5345 Does the work of either
5351 Showing all the debugger help
5355 Showing help for a specific command
5362 use vars qw($summary);
5367 # If we have no operand, assume null.
5368 my $line = shift || '';
5370 # 'h h'. Print the long-format help.
5371 if ( $line =~ /\Ah\s*\z/ ) {
5375 # 'h <something>'. Search for the command and print only its help.
5376 elsif ( my ($asked) = $line =~ /\A(\S.*)\z/ ) {
5378 # support long commands; otherwise bogus errors
5379 # happen when you ask for h on <CR> for example
5380 my $qasked = quotemeta($asked); # for searching; we don't
5381 # want to use it as a pattern.
5382 # XXX: finds CR but not <CR>
5384 # Search the help string for the command.
5386 $help =~ /^ # Start of a line
5388 (?:[IB]<) # Optional markup
5389 $qasked # The requested command
5394 # It's there; pull it out and print it.
5398 (?:[IB]<) # Optional markup
5399 $qasked # The command
5400 ([\s\S]*?) # Description line(s)
5401 \n) # End of last description line
5402 (?!\s) # Next line not starting with
5411 # Not found; not a debugger command.
5413 print_help("B<$asked> is not a debugger command.\n");
5415 } ## end elsif ($line =~ /^(\S.*)$/)
5417 # 'h' - print the summary help.
5419 print_help($summary);
5423 =head3 C<cmd_i> - inheritance display
5425 Display the (nested) parentage of the module or object given.
5432 foreach my $isa ( split( /\s+/, $line ) ) {
5434 ($isa) = DB::eval();
5441 defined( ${"$_\::VERSION"} )
5442 ? ' ' . ${"$_\::VERSION"}
5444 } @{mro::get_linear_isa(ref($isa) || $isa)}
5450 =head3 C<cmd_l> - list lines (command)
5452 Most of the command is taken up with transforming all the different line
5453 specification syntaxes into 'start-stop'. After that is done, the command
5454 runs a loop over C<@dbline> for the specified range of lines. It handles
5455 the printing of each line and any markers (C<==E<gt>> for current line,
5456 C<b> for break on this line, C<a> for action on this line, C<:> for this
5459 We save the last line listed in the C<$start> global for further listing
5466 foreach my $v (@_) {
5476 foreach my $v (@_) {
5484 sub _minify_to_max {
5487 $$ref = _min($$ref, $max);
5492 sub _cmd_l_handle_var_name {
5493 my $var_name = shift;
5495 $evalarg = $var_name;
5497 my ($s) = DB::eval();
5499 # Ooops. Bad scalar.
5501 print {$OUT} "Error: $@\n";
5505 # Good scalar. If it's a reference, find what it points to.
5507 print {$OUT} "Interpreted as: $1 $s\n";
5510 # Call self recursively to really do the command.
5511 return _cmd_l_main( $s );
5514 sub _cmd_l_handle_subname {
5519 $subname =~ s/\'/::/;
5521 # Put it in this package unless it starts with ::.
5522 $subname = $package . "::" . $subname unless $subname =~ /::/;
5524 # Put it in CORE::GLOBAL if t doesn't start with :: and
5525 # it doesn't live in this package and it lives in CORE::GLOBAL.
5526 $subname = "CORE::GLOBAL::$s"
5527 if not defined &$subname
5529 and defined &{"CORE::GLOBAL::$s"};
5531 # Put leading '::' names into 'main::'.
5532 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
5534 # Get name:start-stop from find_sub, and break this up at
5536 my @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
5538 # Pull off start-stop.
5539 my $subrange = pop @pieces;
5541 # If the name contained colons, the split broke it up.
5542 # Put it back together.
5543 $file = join( ':', @pieces );
5545 # If we're not in that file, switch over to it.
5546 if ( $file ne $filename ) {
5547 if (! $slave_editor) {
5548 print {$OUT} "Switching to file '$file'.\n";
5551 # Switch debugger's magic structures.
5552 *dbline = $main::{ '_<' . $file };
5555 } ## end if ($file ne $filename)
5557 # Subrange is 'start-stop'. If this is less than a window full,
5558 # swap it to 'start+', which will list a window from the start point.
5560 if ( eval($subrange) < -$window ) {
5561 $subrange =~ s/-.*/+/;
5564 # Call self recursively to list the range.
5565 return _cmd_l_main( $subrange );
5566 } ## end if ($subrange)
5570 print {$OUT} "Subroutine $subname not found.\n";
5576 # Compute new range to list.
5577 $incr = $window - 1;
5580 return _cmd_l_main( $start . '-' . ( $start + $incr ) );
5584 my ($new_start, $new_incr) = @_;
5586 # Don't reset start for 'l +nnn'.
5587 $start = $new_start if $new_start;
5589 # Increment for list. Use window size if not specified.
5590 # (Allows 'l +' to work.)
5591 $incr = $new_incr || ($window - 1);
5593 # Create a line range we'll understand, and recurse to do it.
5594 return _cmd_l_main( $start . '-' . ( $start + $incr ) );
5597 sub _cmd_l_calc_initial_end_and_i {
5598 my ($spec, $start_match, $end_match) = @_;
5600 # Determine end point; use end of file if not specified.
5601 my $end = ( !defined $start_match ) ? $max :
5602 ( $end_match ? $end_match : $start_match );
5604 # Go on to the end, and then stop.
5605 _minify_to_max(\$end);
5607 # Determine start line.
5608 my $i = $start_match;
5622 my ($spec, $current_line, $start_match, $end_match) = @_;
5625 _cmd_l_calc_initial_end_and_i($spec, $start_match, $end_match);
5627 # If we're running under a slave editor, force it to show the lines.
5628 if ($slave_editor) {
5629 print {$OUT} "\032\032$filename:$i:0\n";
5632 # We're doing it ourselves. We want to show the line and special
5634 # - the current line in execution
5635 # - whether a line is breakable or not
5636 # - whether a line has a break or not
5637 # - whether a line has an action or not
5640 for ( ; $i <= $end ; $i++ ) {
5642 # Check for breakpoints and actions.
5643 my ( $stop, $action );
5645 ( $stop, $action ) = split( /\0/, $dbline{$i} );
5648 # ==> if this is the current line in execution,
5649 # : if it's breakable.
5651 ( $i == $current_line and $filename eq $filename_ini )
5653 : ( $dbline[$i] + 0 ? ':' : ' ' );
5655 # Add break and action indicators.
5656 $arrow .= 'b' if $stop;
5657 $arrow .= 'a' if $action;
5660 print {$OUT} "$i$arrow\t", $dbline[$i];
5662 # Move on to the next line. Drop out on an interrupt.
5667 } ## end for (; $i <= $end ; $i++)
5669 # Line the prompt up; print a newline if the last line listed
5670 # didn't have a newline.
5671 if ($dbline[ $i - 1 ] !~ /\n\z/) {
5674 } ## end else [ if ($slave_editor)
5676 # Save the point we last listed to in case another relative 'l'
5677 # command is desired. Don't let it run off the end.
5679 _minify_to_max(\$start);
5687 # If this is '-something', delete any spaces after the dash.
5688 $spec =~ s/\A-\s*\z/-/;
5690 # If the line is '$something', assume this is a scalar containing a
5692 # Set up for DB::eval() - evaluate in *user* context.
5693 if ( my ($var_name) = $spec =~ /\A(\$.*)/s ) {
5694 return _cmd_l_handle_var_name($var_name);
5696 # l name. Try to find a sub by that name.
5697 elsif ( ($subname) = $spec =~ /\A([\':A-Za-z_][\':\w]*(?:\[.*\])?)/s ) {
5698 return _cmd_l_handle_subname();
5701 elsif ( $spec !~ /\S/ ) {
5702 return _cmd_l_empty();
5704 # l [start]+number_of_lines
5705 elsif ( my ($new_start, $new_incr) = $spec =~ /\A(\d*)\+(\d*)\z/ ) {
5706 return _cmd_l_plus($new_start, $new_incr);
5708 # l start-stop or l start,stop
5709 elsif (my ($s, $e) = $spec =~ /^(?:(-?[\d\$\.]+)(?:[-,]([\d\$\.]+))?)?/ ) {
5710 return _cmd_l_range($spec, $line, $s, $e);
5717 my (undef, $line) = @_;
5719 return _cmd_l_main($line);
5722 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5724 To list breakpoints, the command has to look determine where all of them are
5725 first. It starts a C<%had_breakpoints>, which tells us what all files have
5726 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5727 magic source and breakpoint data structures) to the file, and then look
5728 through C<%dbline> for lines with breakpoints and/or actions, listing them
5729 out. We look through C<%postponed> not-yet-compiled subroutines that have
5730 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5731 that have breakpoints.
5733 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5737 sub _cmd_L_calc_arg {
5738 # If no argument, list everything. Pre-5.8.0 version always lists
5740 my $arg = shift || 'abw';
5741 if ($CommandSet ne '580')
5749 sub _cmd_L_calc_wanted_flags {
5750 my $arg = _cmd_L_calc_arg(shift);
5752 return (map { index($arg, $_) >= 0 ? 1 : 0 } qw(a b w));
5756 sub _cmd_L_handle_breakpoints {
5757 my ($handle_db_line) = @_;
5760 # Look in all the files with breakpoints...
5761 for my $file ( keys %had_breakpoints ) {
5763 # Temporary switch to this file.
5764 local *dbline = $main::{ '_<' . $file };
5766 # Set up to look through the whole file.
5768 my $was; # Flag: did we print something
5771 # For each line in the file ...
5772 for my $i (1 .. $max) {
5774 # We've got something on this line.
5775 if ( defined $dbline{$i} ) {
5777 # Print the header if we haven't.
5779 print {$OUT} "$file:\n";
5783 print {$OUT} " $i:\t", $dbline[$i];
5785 $handle_db_line->($dbline{$i});
5787 # Quit if the user hit interrupt.
5789 last BREAKPOINTS_SCAN;
5791 } ## end if (defined $dbline{$i...
5792 } ## end for my $i (1 .. $max)
5793 } ## end for my $file (keys %had_breakpoints)
5798 sub _cmd_L_handle_postponed_breakpoints {
5799 my ($handle_db_line) = @_;
5801 print {$OUT} "Postponed breakpoints in files:\n";
5804 for my $file ( keys %postponed_file ) {
5805 my $db = $postponed_file{$file};
5806 print {$OUT} " $file:\n";
5807 for my $line ( sort { $a <=> $b } keys %$db ) {
5808 print {$OUT} " $line:\n";
5810 $handle_db_line->($db->{$line});
5813 last POSTPONED_SCANS;
5817 last POSTPONED_SCANS;
5828 my ($action_wanted, $break_wanted, $watch_wanted) =
5829 _cmd_L_calc_wanted_flags(shift);
5831 my $handle_db_line = sub {
5834 my ( $stop, $action ) = split( /\0/, $l );
5836 if ($stop and $break_wanted) {
5837 print {$OUT} " break if (", $stop, ")\n"
5840 if ($action && $action_wanted) {
5841 print {$OUT} " action: ", $action, "\n"
5847 # Breaks and actions are found together, so we look in the same place
5849 if ( $break_wanted or $action_wanted ) {
5850 _cmd_L_handle_breakpoints($handle_db_line);
5853 # Look for breaks in not-yet-compiled subs:
5854 if ( %postponed and $break_wanted ) {
5855 print {$OUT} "Postponed breakpoints in subroutines:\n";
5858 for $subname ( keys %postponed ) {
5859 print {$OUT} " $subname\t$postponed{$subname}\n";
5864 } ## end if (%postponed and $break_wanted)
5866 # Find files that have not-yet-loaded breaks:
5867 my @have = map { # Combined keys
5868 keys %{ $postponed_file{$_} }
5869 } keys %postponed_file;
5871 # If there are any, list them.
5872 if ( @have and ( $break_wanted or $action_wanted ) ) {
5873 _cmd_L_handle_postponed_breakpoints($handle_db_line);
5874 } ## end if (@have and ($break_wanted...
5876 if ( %break_on_load and $break_wanted ) {
5877 print {$OUT} "Breakpoints on load:\n";
5878 BREAK_ON_LOAD: for my $filename ( keys %break_on_load ) {
5879 print {$OUT} " $filename\n";
5880 last BREAK_ON_LOAD if $signal;
5882 } ## end if (%break_on_load and...
5884 if ($watch_wanted and ( $trace & 2 )) {
5885 print {$OUT} "Watch-expressions:\n" if @to_watch;
5886 TO_WATCH: for my $expr (@to_watch) {
5887 print {$OUT} " $expr\n";
5888 last TO_WATCH if $signal;
5895 =head3 C<cmd_M> - list modules (command)
5897 Just call C<list_modules>.
5907 =head3 C<cmd_o> - options (command)
5909 If this is just C<o> by itself, we list the current settings via
5910 C<dump_option>. If there's a nonblank value following it, we pass that on to
5911 C<parse_options> for processing.
5917 my $opt = shift || ''; # opt[=val]
5919 # Nonblank. Try to parse and process.
5920 if ( $opt =~ /^(\S.*)/ ) {
5924 # Blank. List the current option settings.
5932 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5934 Advises the user that the O command has been renamed.
5939 print $OUT "The old O command is now the o command.\n"; # hint
5940 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5941 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5944 =head3 C<cmd_v> - view window (command)
5946 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5947 move back a few lines to list the selected line in context. Uses C<cmd_l>
5948 to do the actual listing after figuring out the range of line to request.
5952 use vars qw($preview);
5958 # Extract the line to list around. (Astute readers will have noted that
5959 # this pattern will match whether or not a numeric line is specified,
5960 # which means that we'll always enter this loop (though a non-numeric
5961 # argument results in no action at all)).
5962 if ( $line =~ /^(\d*)$/ ) {
5964 # Total number of lines to list (a windowful).
5965 $incr = $window - 1;
5967 # Set the start to the argument given (if there was one).
5970 # Back up by the context amount.
5973 # Put together a linespec that cmd_l will like.
5974 $line = $start . '-' . ( $start + $incr );
5977 cmd_l( 'l', $line );
5978 } ## end if ($line =~ /^(\d*)$/)
5981 =head3 C<cmd_w> - add a watch expression (command)
5983 The 5.8 version of this command adds a watch expression if one is specified;
5984 it does nothing if entered with no operands.
5986 We extract the expression, save it, evaluate it in the user's context, and
5987 save the value. We'll re-evaluate it each time the debugger passes a line,
5988 and will stop (see the code at the top of the command loop) if the value
5989 of any of the expressions changes.
5993 sub _add_watch_expr {
5997 push @to_watch, $expr;
5999 # Parameterize DB::eval and call it to get the expression's value
6000 # in the user's context. This version can handle expressions which
6001 # return a list value.
6003 my ($val) = join( ' ', DB::eval() );
6004 $val = ( defined $val ) ? "'$val'" : 'undef';
6006 # Save the current value of the expression.
6007 push @old_watch, $val;
6009 # We are now watching expressions.
6018 # Null expression if no arguments.
6019 my $expr = shift || '';
6021 # If expression is not null ...
6022 if ( $expr =~ /\A\S/ ) {
6023 _add_watch_expr($expr);
6024 } ## end if ($expr =~ /^(\S.*)/)
6026 # You have to give one to get one.
6028 print $OUT "Adding a watch-expression requires an expression\n"; # hint
6034 =head3 C<cmd_W> - delete watch expressions (command)
6036 This command accepts either a watch expression to be removed from the list
6037 of watch expressions, or C<*> to delete them all.
6039 If C<*> is specified, we simply empty the watch expression list and the
6040 watch expression value list. We also turn off the bit that says we've got
6043 If an expression (or partial expression) is specified, we pattern-match
6044 through the expressions and remove the ones that match. We also discard
6045 the corresponding values. If no watch expressions are left, we turn off
6046 the I<watching expressions> bit.
6052 my $expr = shift || '';
6055 if ( $expr eq '*' ) {
6060 print $OUT "Deleting all watch expressions ...\n";
6063 @to_watch = @old_watch = ();
6066 # Delete one of them.
6067 elsif ( $expr =~ /^(\S.*)/ ) {
6069 # Where we are in the list.
6072 # For each expression ...
6073 foreach (@to_watch) {
6074 my $val = $to_watch[$i_cnt];
6076 # Does this one match the command argument?
6077 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
6078 # Yes. Turn it off, and its value too.
6079 splice( @to_watch, $i_cnt, 1 );
6080 splice( @old_watch, $i_cnt, 1 );
6083 } ## end foreach (@to_watch)
6085 # We don't bother to turn watching off because
6086 # a) we don't want to stop calling watchfunction() it it exists
6087 # b) foreach over a null list doesn't do anything anyway
6089 } ## end elsif ($expr =~ /^(\S.*)/)
6091 # No command arguments entered.
6094 "Deleting a watch-expression requires an expression, or '*' for all\n"
6099 ### END of the API section
6101 =head1 SUPPORT ROUTINES
6103 These are general support routines that are used in a number of places
6104 throughout the debugger.
6108 save() saves the user's versions of globals that would mess us up in C<@saved>,
6109 and installs the versions we like better.
6115 # Save eval failure, command failure, extended OS error, output field
6116 # separator, input record separator, output record separator and
6117 # the warning setting.
6118 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
6120 $, = ""; # output field separator is null string
6121 $/ = "\n"; # input record separator is newline
6122 $\ = ""; # output record separator is null string
6123 $^W = 0; # warnings are off
6126 =head2 C<print_lineinfo> - show where we are now
6128 print_lineinfo prints whatever it is that it is handed; it prints it to the
6129 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
6130 us to feed line information to a slave editor without messing up the
6135 sub print_lineinfo {
6137 # Make the terminal sensible if we're not the primary debugger.
6138 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
6142 } ## end sub print_lineinfo
6144 =head2 C<postponed_sub>
6146 Handles setting postponed breakpoints in subroutines once they're compiled.
6147 For breakpoints, we use C<DB::find_sub> to locate the source file and line
6148 range for the subroutine, then mark the file as having a breakpoint,
6149 temporarily switch the C<*dbline> glob over to the source file, and then
6150 search the given range of lines to find a breakable line. If we find one,
6151 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
6155 # The following takes its argument via $evalarg to preserve current @_
6159 # Get the subroutine name.
6160 my $subname = shift;
6162 # If this is a 'break +<n> if <condition>' ...
6163 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
6165 # If there's no offset, use '+0'.
6166 my $offset = $1 || 0;
6168 # find_sub's value is 'fullpath-filename:start-stop'. It's
6169 # possible that the filename might have colons in it too.
6170 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
6173 # We got the start line. Add the offset '+<n>' from
6174 # $postponed{subname}.
6177 # Switch to the file this sub is in, temporarily.
6178 local *dbline = $main::{ '_<' . $file };
6180 # No warnings, please.
6181 local $^W = 0; # != 0 is magical below
6183 # This file's got a breakpoint in it.
6184 $had_breakpoints{$file} |= 1;
6186 # Last line in file.
6189 # Search forward until we hit a breakable line or get to
6190 # the end of the file.
6191 ++$i until $dbline[$i] != 0 or $i >= $max;
6193 # Copy the breakpoint in and delete it from %postponed.
6194 $dbline{$i} = delete $postponed{$subname};
6197 # find_sub didn't find the sub.
6200 print $OUT "Subroutine $subname not found.\n";
6203 } ## end if ($postponed{$subname...
6204 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
6206 #print $OUT "In postponed_sub for '$subname'.\n";
6207 } ## end sub postponed_sub
6211 Called after each required file is compiled, but before it is executed;
6212 also called if the name of a just-compiled subroutine is a key of
6213 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
6214 etc.) into the just-compiled code.
6216 If this is a C<require>'d file, the incoming parameter is the glob
6217 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
6219 If it's a subroutine, the incoming parameter is the subroutine name.
6225 # If there's a break, process it.
6226 if ($ImmediateStop) {
6228 # Right, we've stopped. Turn it off.
6231 # Enter the command loop when DB::DB gets called.
6235 # If this is a subroutine, let postponed_sub() deal with it.
6236 if (ref(\$_[0]) ne 'GLOB') {
6237 return postponed_sub(@_);
6240 # Not a subroutine. Deal with the file.
6241 local *dbline = shift;
6242 my $filename = $dbline;
6243 $filename =~ s/^_<//;
6245 $signal = 1, print $OUT "'$filename' loaded...\n"
6246 if $break_on_load{$filename};
6247 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
6249 # Do we have any breakpoints to put in this file?
6250 return unless $postponed_file{$filename};
6252 # Yes. Mark this file as having breakpoints.
6253 $had_breakpoints{$filename} |= 1;
6255 # "Cannot be done: insufficient magic" - we can't just put the
6256 # breakpoints saved in %postponed_file into %dbline by assigning
6257 # the whole hash; we have to do it one item at a time for the
6258 # breakpoints to be set properly.
6259 #%dbline = %{$postponed_file{$filename}};
6261 # Set the breakpoints, one at a time.
6264 for $key ( keys %{ $postponed_file{$filename} } ) {
6266 # Stash the saved breakpoint into the current file's magic line array.
6267 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
6270 # This file's been compiled; discard the stored breakpoints.
6271 delete $postponed_file{$filename};
6273 } ## end sub postponed
6277 C<dumpit> is the debugger's wrapper around dumpvar.pl.
6279 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
6280 a reference to a variable (the thing to be dumped) as its input.
6282 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
6283 the currently-selected filehandle, thank you very much). The current
6284 values of the package globals C<$single> and C<$trace> are backed up in
6285 lexicals, and they are turned off (this keeps the debugger from trying
6286 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
6287 preserve its current value and it is set to zero to prevent entry/exit
6288 messages from printing, and C<$doret> is localized as well and set to -2 to
6289 prevent return values from being shown.
6291 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
6292 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
6293 installed version in C<@INC>, yours will be used instead. Possible security
6296 It then checks to see if the subroutine C<main::dumpValue> is now defined
6297 it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
6298 localizes the globals necessary for things to be sane when C<main::dumpValue()>
6299 is called, and picks up the variable to be dumped from the parameter list.
6301 It checks the package global C<%options> to see if there's a C<dumpDepth>
6302 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
6303 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
6304 structure: -1 means dump everything.
6306 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
6309 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
6310 and we then return to the caller.
6316 # Save the current output filehandle and switch to the one
6317 # passed in as the first parameter.
6318 my $savout = select(shift);
6320 # Save current settings of $single and $trace, and then turn them off.
6321 my $osingle = $single;
6322 my $otrace = $trace;
6323 $single = $trace = 0;
6325 # XXX Okay, what do $frame and $doret do, again?
6329 # Load dumpvar.pl unless we've already got the sub we need from it.
6330 unless ( defined &main::dumpValue ) {
6331 do 'dumpvar.pl' or die $@;
6334 # If the load succeeded (or we already had dumpvalue()), go ahead
6336 if ( defined &main::dumpValue ) {
6341 my $maxdepth = shift || $option{dumpDepth};
6342 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
6343 main::dumpValue( $v, $maxdepth );
6344 } ## end if (defined &main::dumpValue)
6346 # Oops, couldn't load dumpvar.pl.
6349 print $OUT "dumpvar.pl not available.\n";
6352 # Reset $single and $trace to their old values.
6356 # Restore the old filehandle.
6360 =head2 C<print_trace>
6362 C<print_trace>'s job is to print a stack trace. It does this via the
6363 C<dump_trace> routine, which actually does all the ferreting-out of the
6364 stack trace data. C<print_trace> takes care of formatting it nicely and
6365 printing it to the proper filehandle.
6373 The filehandle to print to.
6377 How many frames to skip before starting trace.
6381 How many frames to print.
6385 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
6389 The original comment below seems to be noting that the traceback may not be
6390 correct if this routine is called in a tied method.
6394 # Tied method do not create a context, so may get wrong message:
6400 # If this is going to a slave editor, but we're not the primary
6401 # debugger, reset it first.
6403 if $fh eq $LINEINFO # slave editor
6404 and $LINEINFO eq $OUT # normal output
6405 and $term_pid != $$; # not the primary
6407 # Collect the actual trace information to be formatted.
6408 # This is an array of hashes of subroutine call info.
6409 my @sub = dump_trace( $_[0] + 1, $_[1] );
6411 # Grab the "short report" flag from @_.
6412 my $short = $_[2]; # Print short report, next one for sub name
6414 # Run through the traceback info, format it, and print it.
6416 for my $i (0 .. $#sub) {
6418 # Drop out if the user has lost interest and hit control-C.
6421 # Set the separator so arrys print nice.
6424 # Grab and stringify the arguments if they are there.
6426 defined $sub[$i]{args}
6427 ? "(@{ $sub[$i]{args} })"
6430 # Shorten them up if $maxtrace says they're too long.
6431 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
6432 if length $args > $maxtrace;
6434 # Get the file name.
6435 my $file = $sub[$i]{file};
6437 # Put in a filename header if short is off.
6438 $file = $file eq '-e' ? $file : "file '$file'" unless $short;
6440 # Get the actual sub's name, and shorten to $maxtrace's requirement.
6441 $s = $sub[$i]{'sub'};
6442 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
6444 # Short report uses trimmed file and sub names.
6446 my $sub = @_ >= 4 ? $_[3] : $s;
6447 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
6448 } ## end if ($short)
6450 # Non-short report includes full names.
6452 print $fh "$sub[$i]{context} = $s$args"
6453 . " called from $file"
6454 . " line $sub[$i]{line}\n";
6456 } ## end for my $i (0 .. $#sub)
6457 } ## end sub print_trace
6459 =head2 dump_trace(skip[,count])
6461 Actually collect the traceback information available via C<caller()>. It does
6462 some filtering and cleanup of the data, but mostly it just collects it to
6463 make C<print_trace()>'s job easier.
6465 C<skip> defines the number of stack frames to be skipped, working backwards
6466 from the most current. C<count> determines the total number of frames to
6467 be returned; all of them (well, the first 10^9) are returned if C<count>
6470 This routine returns a list of hashes, from most-recent to least-recent
6471 stack frame. Each has the following keys and values:
6475 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
6477 =item * C<sub> - subroutine name, or C<eval> information
6479 =item * C<args> - undef, or a reference to an array of arguments
6481 =item * C<file> - the file in which this item was defined (if any)
6483 =item * C<line> - the line on which it was defined
6489 sub _dump_trace_calc_saved_single_arg
6491 my ($nothard, $arg) = @_;
6494 if ( not defined $arg ) { # undefined parameter
6498 elsif ( $nothard and tied $arg ) { # tied parameter
6501 elsif ( $nothard and $type = ref $arg ) { # reference
6502 return "ref($type)";
6504 else { # can be stringified
6506 "$arg"; # Safe to stringify now - should not call f().
6508 # Backslash any single-quotes or backslashes.
6511 # Single-quote it unless it's a number or a colon-separated
6514 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
6516 # Turn high-bit characters into meta-whatever.
6517 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
6519 # Turn control characters into ^-whatever.
6520 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
6526 sub _dump_trace_calc_save_args {
6530 map { _dump_trace_calc_saved_single_arg($nothard, $_) } @args
6536 # How many levels to skip.
6539 # How many levels to show. (1e9 is a cheap way of saying "all of them";
6540 # it's unlikely that we'll have more than a billion stack frames. If you
6541 # do, you've got an awfully big machine...)
6542 my $count = shift || 1e9;
6544 # We increment skip because caller(1) is the first level *back* from
6545 # the current one. Add $skip to the count of frames so we have a
6546 # simple stop criterion, counting from $skip to $count+$skip.
6550 # These variables are used to capture output from caller();
6551 my ( $p, $file, $line, $sub, $h, $context );
6553 my ( $e, $r, @sub, $args );
6555 # XXX Okay... why'd we do that?
6556 my $nothard = not $frame & 8;
6559 # Do not want to trace this.
6560 my $otrace = $trace;
6563 # Start out at the skip count.
6564 # If we haven't reached the number of frames requested, and caller() is
6565 # still returning something, stay in the loop. (If we pass the requested
6566 # number of stack frames, or we run out - caller() returns nothing - we
6568 # Up the stack frame index to go back one more level each time.
6572 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
6577 # Go through the arguments and save them for later.
6578 my $save_args = _dump_trace_calc_save_args($nothard);
6580 # If context is true, this is array (@)context.
6581 # If context is false, this is scalar ($) context.
6582 # If neither, context isn't defined. (This is apparently a 'can't
6584 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
6586 # if the sub has args ($h true), make an anonymous array of the
6588 $args = $h ? $save_args : undef;
6590 # remove trailing newline-whitespace-semicolon-end of line sequence
6591 # from the eval text, if any.
6592 $e =~ s/\n\s*\;\s*\Z// if $e;
6594 # Escape backslashed single-quotes again if necessary.
6595 $e =~ s/([\\\'])/\\$1/g if $e;
6597 # if the require flag is true, the eval text is from a require.
6599 $sub = "require '$e'";
6602 # if it's false, the eval text is really from an eval.
6603 elsif ( defined $r ) {
6607 # If the sub is '(eval)', this is a block eval, meaning we don't
6608 # know what the eval'ed text actually was.
6609 elsif ( $sub eq '(eval)' ) {
6610 $sub = "eval {...}";
6613 # Stick the collected information into @sub as an anonymous hash.
6617 context => $context,
6625 # Stop processing frames if the user hit control-C.
6627 } ## end for ($i = $skip ; $i < ...
6629 # Restore the trace value again.
6632 } ## end sub dump_trace
6636 C<action()> takes input provided as the argument to an add-action command,
6637 either pre- or post-, and makes sure it's a complete command. It doesn't do
6638 any fancy parsing; it just keeps reading input until it gets a string
6639 without a trailing backslash.
6646 while ( $action =~ s/\\$// ) {
6648 # We have a backslash on the end. Read more.
6650 } ## end while ($action =~ s/\\$//)
6652 # Return the assembled action.
6658 This routine mostly just packages up a regular expression to be used
6659 to check that the thing it's being matched against has properly-matched
6662 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
6663 speeds things up by only creating the qr//'ed expression once; if it's
6664 already defined, we don't try to define it again. A speed hack.
6668 use vars qw($balanced_brace_re);
6672 # I hate using globals!
6673 $balanced_brace_re ||= qr{
6676 (?> [^{}] + ) # Non-parens without backtracking
6678 (??{ $balanced_brace_re }) # Group with matching parens
6682 return $_[0] !~ m/$balanced_brace_re/;
6683 } ## end sub unbalanced
6687 C<gets()> is a primitive (very primitive) routine to read continuations.
6688 It was devised for reading continuations for actions.
6689 it just reads more input with C<readline()> and returns it.
6694 return DB::readline("cont: ");
6697 =head2 C<_db_system()> - handle calls to<system()> without messing up the debugger
6699 The C<system()> function assumes that it can just go ahead and use STDIN and
6700 STDOUT, but under the debugger, we want it to use the debugger's input and
6703 C<_db_system()> socks away the program's STDIN and STDOUT, and then substitutes
6704 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
6705 and then puts everything back again.
6711 # We save, change, then restore STDIN and STDOUT to avoid fork() since
6712 # some non-Unix systems can do system() but have problems with fork().
6713 open( SAVEIN, "<&STDIN" ) || db_warn("Can't save STDIN");
6714 open( SAVEOUT, ">&STDOUT" ) || db_warn("Can't save STDOUT");
6715 open( STDIN, "<&IN" ) || db_warn("Can't redirect STDIN");
6716 open( STDOUT, ">&OUT" ) || db_warn("Can't redirect STDOUT");
6718 # XXX: using csh or tcsh destroys sigint retvals!
6720 open( STDIN, "<&SAVEIN" ) || db_warn("Can't restore STDIN");
6721 open( STDOUT, ">&SAVEOUT" ) || db_warn("Can't restore STDOUT");
6725 # most of the $? crud was coping with broken cshisms
6727 db_warn( "(Command exited ", ( $? >> 8 ), ")\n" );
6731 "(Command died of SIG#",
6733 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6742 *system = \&_db_system;
6744 =head1 TTY MANAGEMENT
6746 The subs here do some of the terminal management for multiple debuggers.
6750 Top-level function called when we want to set up a new terminal for use
6753 If the C<noTTY> debugger option was set, we'll either use the terminal
6754 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6755 to find one. If we're a forked debugger, we call C<resetterm> to try to
6756 get a whole new terminal if we can.
6758 In either case, we set up the terminal next. If the C<ReadLine> option was
6759 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6760 the appropriate attributes. We then
6764 use vars qw($ornaments);
6765 use vars qw($rl_attribs);
6769 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6772 require Term::ReadLine;
6774 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6777 my ( $i, $o ) = split $tty, /,/;
6778 $o = $i unless defined $o;
6779 open( IN, "<$i" ) or die "Cannot open TTY '$i' for read: $!";
6780 open( OUT, ">$o" ) or die "Cannot open TTY '$o' for write: $!";
6786 # We don't have a TTY - try to find one via Term::Rendezvous.
6788 require Term::Rendezvous;
6790 # See if we have anything to pass to Term::Rendezvous.
6791 # Use $HOME/.perldbtty$$ if not.
6792 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6794 # Rendezvous and get the filehandles.
6795 my $term_rv = Term::Rendezvous->new( $rv );
6797 $OUT = $term_rv->OUT;
6798 } ## end else [ if ($tty)
6799 } ## end if ($notty)
6801 # We're a daughter debugger. Try to fork off another TTY.
6802 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6806 # If we shouldn't use Term::ReadLine, don't.
6808 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6811 # We're using Term::ReadLine. Get all the attributes for this terminal.
6813 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6815 $rl_attribs = $term->Attribs;
6816 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6817 if defined $rl_attribs->{basic_word_break_characters}
6818 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6819 $rl_attribs->{special_prefixes} = '$@&%';
6820 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6821 $rl_attribs->{completion_function} = \&db_complete;
6822 } ## end else [ if (!$rl)
6824 # Set up the LINEINFO filehandle.
6825 $LINEINFO = $OUT unless defined $LINEINFO;
6826 $lineinfo = $console unless defined $lineinfo;
6832 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6833 $term->SetHistory(@hist);
6836 # XXX Ornaments are turned on unconditionally, which is not
6837 # always a good thing.
6838 ornaments($ornaments) if defined $ornaments;
6840 } ## end sub setterm
6843 $histfile //= option_val("HistFile", undef);
6844 return unless defined $histfile;
6845 open my $fh, "<", $histfile or return;
6856 return unless defined $histfile;
6857 eval { require File::Path } or return;
6858 eval { require File::Basename } or return;
6859 File::Path::mkpath(File::Basename::dirname($histfile));
6860 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6861 $histsize //= option_val("HistSize",100);
6862 my @copy = grep { $_ ne '?' } @hist;
6863 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6864 for ($start .. $#copy) {
6865 print $fh "$copy[$_]\n";
6867 close $fh or die "Could not write '$histfile': $!";
6870 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6872 When the process being debugged forks, or the process invokes a command
6873 via C<system()> which starts a new debugger, we need to be able to get a new
6874 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6875 fight over the terminal, and you can never quite be sure who's going to get the
6876 input you're typing.
6878 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6879 is tasked with doing all the necessary operating system mojo to get a new
6880 TTY (and probably another window) and to direct the new debugger to read and
6883 The debugger provides C<get_fork_TTY> functions which work for TCP
6884 socket servers, X11, OS/2, and Mac OS X. Other systems are not
6885 supported. You are encouraged to write C<get_fork_TTY> functions which
6886 work for I<your> platform and contribute them.
6888 =head3 C<socket_get_fork_TTY>
6892 sub connect_remoteport {
6895 my $socket = IO::Socket::INET->new(
6897 PeerAddr => $remoteport,
6901 die "Unable to connect to remote host: $remoteport\n";
6906 sub socket_get_fork_TTY {
6907 $tty = $LINEINFO = $IN = $OUT = connect_remoteport();
6909 # Do I need to worry about setting $term?
6911 reset_IN_OUT( $IN, $OUT );
6915 =head3 C<xterm_get_fork_TTY>
6917 This function provides the C<get_fork_TTY> function for X11. If a
6918 program running under the debugger forks, a new <xterm> window is opened and
6919 the subsidiary debugger is directed there.
6921 The C<open()> call is of particular note here. We have the new C<xterm>
6922 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6923 command (which prints the device name of the TTY we'll want to use for input
6924 and output to STDOUT, then C<sleep> for a very long time, routing this output
6925 to file number 3. This way we can simply read from the <XT> filehandle (which
6926 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6928 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6933 sub xterm_get_fork_TTY {
6934 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6936 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6939 # Get the output from 'tty' and clean it up a little.
6943 $pidprompt = ''; # Shown anyway in titlebar
6945 # We need $term defined or we can not switch to the newly created xterm
6946 if ($tty ne '' && !defined $term) {
6947 require Term::ReadLine;
6949 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6952 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6955 # There's our new TTY.
6957 } ## end sub xterm_get_fork_TTY
6959 =head3 C<os2_get_fork_TTY>
6961 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6965 # This example function resets $IN, $OUT itself
6967 sub os2_get_fork_TTY { # A simplification of the following (and works without):
6969 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6970 my %opt = ( title => "Daughter Perl debugger $pids $name",
6971 ($rl ? (read_by_key => 1) : ()) );
6972 require OS2::Process;
6973 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
6975 $pidprompt = ''; # Shown anyway in titlebar
6976 reset_IN_OUT($in, $out);
6978 return ''; # Indicate that reset_IN_OUT is called
6979 } ## end sub os2_get_fork_TTY
6981 =head3 C<macosx_get_fork_TTY>
6983 The Mac OS X version uses AppleScript to tell Terminal.app to create
6988 # Notes about Terminal.app's AppleScript support,
6989 # (aka things that might break in future OS versions).
6991 # The "do script" command doesn't return a reference to the new window
6992 # it creates, but since it appears frontmost and windows are enumerated
6993 # front to back, we can use "first window" === "window 1".
6995 # Since "do script" is implemented by supplying the argument (plus a
6996 # return character) as terminal input, there's a potential race condition
6997 # where the debugger could beat the shell to reading the command.
6998 # To prevent this, we wait for the screen to clear before proceeding.
7001 # There's no direct accessor for the tty device name, so we fiddle
7002 # with the window title options until it says what we want.
7005 # There _is_ a direct accessor for the tty device name, _and_ there's
7006 # a new possible component of the window title (the name of the settings
7007 # set). A separate version is needed.
7009 my @script_versions=
7011 ([237, <<'__LEOPARD__'],
7012 tell application "Terminal"
7013 do script "clear;exec sleep 100000"
7014 tell first tab of first window
7016 set custom title to "forked perl debugger"
7017 set title displays custom title to true
7018 repeat while (length of first paragraph of (get contents)) > 0
7026 [100, <<'__JAGUAR_TIGER__'],
7027 tell application "Terminal"
7028 do script "clear;exec sleep 100000"
7030 set title displays shell path to false
7031 set title displays window size to false
7032 set title displays file name to false
7033 set title displays device name to true
7034 set title displays custom title to true
7035 set custom title to ""
7036 copy "/dev/" & name to thetty
7037 set custom title to "forked perl debugger"
7038 repeat while (length of first paragraph of (get contents)) > 0
7048 sub macosx_get_fork_TTY
7050 my($version,$script,$pipe,$tty);
7052 return unless $version=$ENV{TERM_PROGRAM_VERSION};
7053 foreach my $entry (@script_versions) {
7054 if ($version>=$entry->[0]) {
7055 $script=$entry->[1];
7059 return unless defined($script);
7060 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
7061 $tty=readline($pipe);
7063 return unless defined($tty) && $tty =~ m(^/dev/);
7068 =head2 C<create_IN_OUT($flags)>
7070 Create a new pair of filehandles, pointing to a new TTY. If impossible,
7071 try to diagnose why.
7077 =item * 1 - Don't know how to create a new TTY.
7079 =item * 2 - Debugger has forked, but we can't get a new TTY.
7081 =item * 4 - standard debugger startup is happening.
7087 use vars qw($fork_TTY);
7089 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
7091 # If we know how to get a new TTY, do it! $in will have
7092 # the TTY name if get_fork_TTY works.
7093 my $in = get_fork_TTY(@_) if defined &get_fork_TTY;
7095 # It used to be that
7096 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
7098 if ( not defined $in ) {
7101 # We don't know how.
7102 print_help(<<EOP) if $why == 1;
7103 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
7107 print_help(<<EOP) if $why == 2;
7108 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
7109 This may be an asynchronous session, so the parent debugger may be active.
7112 # Note that both debuggers are fighting over the same input.
7113 print_help(<<EOP) if $why != 4;
7114 Since two debuggers fight for the same TTY, input is severely entangled.
7118 I know how to switch the output to a different window in xterms, OS/2
7119 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
7120 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
7121 B<DB::get_fork_TTY()> returning this.
7123 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
7124 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
7127 } ## end if (not defined $in)
7128 elsif ( $in ne '' ) {
7132 $console = ''; # Indicate no need to open-from-the-console
7135 } ## end sub create_IN_OUT
7139 Handles rejiggering the prompt when we've forked off a new debugger.
7141 If the new debugger happened because of a C<system()> that invoked a
7142 program under the debugger, the arrow between the old pid and the new
7143 in the prompt has I<two> dashes instead of one.
7145 We take the current list of pids and add this one to the end. If there
7146 isn't any list yet, we make one up out of the initial pid associated with
7147 the terminal and our new pid, sticking an arrow (either one-dashed or
7148 two dashed) in between them.
7150 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
7151 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
7156 sub resetterm { # We forked, so we need a different TTY
7158 # Needs to be passed to create_IN_OUT() as well.
7161 # resetterm(2): got in here because of a system() starting a debugger.
7162 # resetterm(1): just forked.
7163 my $systemed = $in > 1 ? '-' : '';
7165 # If there's already a list of pids, add this to the end.
7167 $pids =~ s/\]/$systemed->$$]/;
7170 # No pid list. Time to make one.
7172 $pids = "[$term_pid->$$]";
7175 # The prompt we're going to be using for this debugger.
7178 # We now 0wnz this terminal.
7181 # Just return if we're not supposed to try to create a new TTY.
7182 return unless $CreateTTY & $in;
7184 # Try to create a new IN/OUT pair.
7186 } ## end sub resetterm
7190 First, we handle stuff in the typeahead buffer. If there is any, we shift off
7191 the next line, print a message saying we got it, add it to the terminal
7192 history (if possible), and return it.
7194 If there's nothing in the typeahead buffer, check the command filehandle stack.
7195 If there are any filehandles there, read from the last one, and return the line
7196 if we got one. If not, we pop the filehandle off and close it, and try the
7197 next one up the stack.
7199 If we've emptied the filehandle stack, we check to see if we've got a socket
7200 open, and we read that and return it if we do. If we don't, we just call the
7201 core C<readline()> and return its value.
7207 # Localize to prevent it from being smashed in the program being debugged.
7210 # If there are stacked filehandles to read from ...
7211 # (Handle it before the typeahead, because we may call source/etc. from
7215 # Read from the last one in the stack.
7216 my $line = CORE::readline( $cmdfhs[-1] );
7218 # If we got a line ...
7220 ? ( print $OUT ">> $line" and return $line ) # Echo and return
7221 : close pop @cmdfhs; # Pop and close
7222 } ## end while (@cmdfhs)
7224 # Pull a line out of the typeahead if there's stuff there.
7227 # How many lines left.
7228 my $left = @typeahead;
7230 # Get the next line.
7231 my $got = shift @typeahead;
7233 # Print a message saying we got input from the typeahead.
7235 print $OUT "auto(-$left)", shift, $got, "\n";
7237 # Add it to the terminal history (if possible).
7238 $term->AddHistory($got)
7240 and defined $term->Features->{addHistory};
7242 } ## end if (@typeahead)
7244 # We really need to read some input. Turn off entry/exit trace and
7245 # return value printing.
7249 # Nothing on the filehandle stack. Socket?
7250 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
7252 # Send anything we have to send.
7253 $OUT->write( join( '', @_ ) );
7255 # Receive anything there is to receive.
7260 while ($first_time or (length($buf) && ($stuff .= $buf) !~ /\n/))
7263 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
7264 # XXX Don't know. You tell me.
7269 } ## end if (ref $OUT and UNIVERSAL::isa...
7271 # No socket. Just read from the terminal.
7273 return $term->readline(@_);
7275 } ## end sub readline
7277 =head1 OPTIONS SUPPORT ROUTINES
7279 These routines handle listing and setting option values.
7281 =head2 C<dump_option> - list the current value of an option setting
7283 This routine uses C<option_val> to look up the value for an option.
7284 It cleans up escaped single-quotes and then displays the option and
7290 my ( $opt, $val ) = @_;
7291 $val = option_val( $opt, 'N/A' );
7292 $val =~ s/([\\\'])/\\$1/g;
7293 printf $OUT "%20s = '%s'\n", $opt, $val;
7294 } ## end sub dump_option
7296 sub options2remember {
7297 foreach my $k (@RememberOnROptions) {
7298 $option{$k} = option_val( $k, 'N/A' );
7303 =head2 C<option_val> - find the current value of an option
7305 This can't just be a simple hash lookup because of the indirect way that
7306 the option values are stored. Some are retrieved by calling a subroutine,
7307 some are just variables.
7309 You must supply a default value to be used in case the option isn't set.
7314 my ( $opt, $default ) = @_;
7317 # Does this option exist, and is it a variable?
7318 # If so, retrieve the value via the value in %optionVars.
7319 if ( defined $optionVars{$opt}
7320 and defined ${ $optionVars{$opt} } )
7322 $val = ${ $optionVars{$opt} };
7325 # Does this option exist, and it's a subroutine?
7326 # If so, call the subroutine via the ref in %optionAction
7327 # and capture the value.
7328 elsif ( defined $optionAction{$opt}
7329 and defined &{ $optionAction{$opt} } )
7331 $val = &{ $optionAction{$opt} }();
7334 # If there's an action or variable for the supplied option,
7335 # but no value was set, use the default.
7336 elsif (defined $optionAction{$opt} and not defined $option{$opt}
7337 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
7342 # Otherwise, do the simple hash lookup.
7344 $val = $option{$opt};
7347 # If the value isn't defined, use the default.
7348 # Then return whatever the value is.
7349 $val = $default unless defined $val;
7351 } ## end sub option_val
7353 =head2 C<parse_options>
7355 Handles the parsing and execution of option setting/displaying commands.
7357 An option entered by itself is assumed to be I<set me to 1> (the default value)
7358 if the option is a boolean one. If not, the user is prompted to enter a valid
7359 value or to query the current value (via C<option? >).
7361 If C<option=value> is entered, we try to extract a quoted string from the
7362 value (if it is quoted). If it's not, we just use the whole value as-is.
7364 We load any modules required to service this option, and then we set it: if
7365 it just gets stuck in a variable, we do that; if there's a subroutine to
7366 handle setting the option, we call that.
7368 Finally, if we're running in interactive mode, we display the effect of the
7369 user's command back to the terminal, skipping this if we're setting things
7370 during initialization.
7380 # These options need a value. Don't allow them to be clobbered by accident.
7381 my %opt_needs_val = map { ( $_ => 1 ) } qw{
7382 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
7383 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
7386 while (length($s)) {
7389 # Clean off excess leading whitespace.
7390 $s =~ s/^\s+// && next;
7392 # Options are always all word characters, followed by a non-word
7394 if ($s !~ s/^(\w+)(\W?)//) {
7395 print {$OUT} "Invalid option '$s'\n";
7398 my ( $opt, $sep ) = ( $1, $2 );
7400 # Make sure that such an option exists.
7401 my $matches = ( grep { /^\Q$opt/ && ( $option = $_ ) } @options )
7402 || ( grep { /^\Q$opt/i && ( $option = $_ ) } @options );
7405 print {$OUT} "Unknown option '$opt'\n";
7409 print {$OUT} "Ambiguous option '$opt'\n";
7414 # '?' as separator means query, but must have whitespace after it.
7415 if ( "?" eq $sep ) {
7417 print {$OUT} "Option query '$opt?' followed by non-space '$s'\n" ;
7422 #&dump_option($opt);
7423 } ## end if ("?" eq $sep)
7425 # Separator is whitespace (or just a carriage return).
7426 # They're going for a default, which we assume is 1.
7427 elsif ( $sep !~ /\S/ ) {
7429 $val = "1"; # this is an evil default; make 'em set it!
7432 # Separator is =. Trying to set a value.
7433 elsif ( $sep eq "=" ) {
7435 # If quoted, extract a quoted string.
7436 if ($s =~ s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
7438 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
7441 # Not quoted. Use the whole thing. Warn about 'option='.
7445 print OUT qq(Option better cleared using $opt=""\n)
7447 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
7449 } ## end elsif ($sep eq "=")
7451 # "Quoted" with [], <>, or {}.
7452 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
7454 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
7455 $s =~ s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
7456 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last;
7457 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
7458 } ## end else [ if ("?" eq $sep)
7460 # Exclude non-booleans from getting set to 1 by default.
7461 if ( $opt_needs_val{$option} && $val_defaulted ) {
7462 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
7464 "Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n";
7466 } ## end if ($opt_needs_val{$option...
7468 # Save the option value.
7469 $option{$option} = $val if defined $val;
7471 # Load any module that this option requires.
7472 if ( defined($optionRequire{$option}) && defined($val) ) {
7476 require '$optionRequire{$option}';
7478 } || die $@ # XXX: shouldn't happen
7482 # Stick it in the proper variable if it goes in a variable.
7483 if (defined($optionVars{$option}) && defined($val)) {
7484 ${ $optionVars{$option} } = $val;
7487 # Call the appropriate sub if it gets set via sub.
7488 if (defined($optionAction{$option})
7489 && defined (&{ $optionAction{$option} })
7492 &{ $optionAction{$option} }($val);
7495 # Not initialization - echo the value we set it to.
7496 dump_option($option) if ($OUT ne \*STDERR);
7497 } ## end while (length)
7498 } ## end sub parse_options
7500 =head1 RESTART SUPPORT
7502 These routines are used to store (and restore) lists of items in environment
7503 variables during a restart.
7507 Set_list packages up items to be stored in a set of environment variables
7508 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
7509 the values). Values outside the standard ASCII charset are stored by encoding
7510 then as hexadecimal values.
7515 my ( $stem, @list ) = @_;
7518 # VAR_n: how many we have. Scalar assignment gets the number of items.
7519 $ENV{"${stem}_n"} = @list;
7521 # Grab each item in the list, escape the backslashes, encode the non-ASCII
7522 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
7523 for my $i ( 0 .. $#list ) {
7525 $val =~ s/\\/\\\\/g;
7526 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
7527 $ENV{"${stem}_$i"} = $val;
7528 } ## end for $i (0 .. $#list)
7529 } ## end sub set_list
7533 Reverse the set_list operation: grab VAR_n to see how many we should be getting
7534 back, and then pull VAR_0, VAR_1. etc. back out.
7541 my $n = delete $ENV{"${stem}_n"};
7543 for my $i ( 0 .. $n - 1 ) {
7544 $val = delete $ENV{"${stem}_$i"};
7545 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
7549 } ## end sub get_list
7551 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
7555 The C<catch()> subroutine is the essence of fast and low-impact. We simply
7556 set an already-existing global scalar variable to a constant value. This
7557 avoids allocating any memory possibly in the middle of something that will
7558 get all confused if we do, particularly under I<unsafe signals>.
7564 return; # Put nothing on the stack - malloc/free land!
7569 C<warn> emits a warning, by joining together its arguments and printing
7570 them, with couple of fillips.
7572 If the composited message I<doesn't> end with a newline, we automatically
7573 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
7574 to be set to the filehandle to be used to output warnings; it makes no
7575 assumptions about what filehandles are available.
7580 my ($msg) = join( "", @_ );
7581 $msg .= ": $!\n" unless $msg =~ /\n$/;
7588 =head1 INITIALIZATION TTY SUPPORT
7590 =head2 C<reset_IN_OUT>
7592 This routine handles restoring the debugger's input and output filehandles
7593 after we've tried and failed to move them elsewhere. In addition, it assigns
7594 the debugger's output filehandle to $LINEINFO if it was already open there.
7599 my $switch_li = $LINEINFO eq $OUT;
7601 # If there's a term and it's able to get a new tty, try to get one.
7602 if ( $term and $term->Features->{newTTY} ) {
7603 ( $IN, $OUT ) = ( shift, shift );
7604 $term->newTTY( $IN, $OUT );
7607 # This term can't get a new tty now. Better luck later.
7609 _db_warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n");
7612 # Set the filehndles up as they were.
7614 ( $IN, $OUT ) = ( shift, shift );
7617 # Unbuffer the output filehandle.
7620 # Point LINEINFO to the same output filehandle if it was there before.
7621 $LINEINFO = $OUT if $switch_li;
7622 } ## end sub reset_IN_OUT
7624 =head1 OPTION SUPPORT ROUTINES
7626 The following routines are used to process some of the more complicated
7631 Sets the input and output filehandles to the specified files or pipes.
7632 If the terminal supports switching, we go ahead and do it. If not, and
7633 there's already a terminal in place, we save the information to take effect
7636 If there's no terminal yet (for instance, during debugger initialization),
7637 we go ahead and set C<$console> and C<$tty> to the file indicated.
7643 if ( @_ and $term and $term->Features->{newTTY} ) {
7645 # This terminal supports switching to a new TTY.
7646 # Can be a list of two files, or on string containing both names,
7648 # XXX Should this perhaps be an assignment from @_?
7649 my ( $in, $out ) = shift;
7652 # Split list apart if supplied.
7653 ( $in, $out ) = split /,/, $in, 2;
7657 # Use the same file for both input and output.
7661 # Open file onto the debugger's filehandles, if you can.
7662 open IN, $in or die "cannot open '$in' for read: $!";
7663 open OUT, ">$out" or die "cannot open '$out' for write: $!";
7665 # Swap to the new filehandles.
7666 reset_IN_OUT( \*IN, \*OUT );
7668 # Save the setting for later.
7670 } ## end if (@_ and $term and $term...
7672 # Terminal doesn't support new TTY, or doesn't support readline.
7673 # Can't do it now, try restarting.
7675 _db_warn("Too late to set TTY, enabled on next 'R'!\n");
7678 # Useful if done through PERLDB_OPTS:
7679 $console = $tty = shift if @_;
7681 # Return whatever the TTY is.
7687 Sets the C<$notty> global, controlling whether or not the debugger tries to
7688 get a terminal to read from. If called after a terminal is already in place,
7689 we save the value to use it if we're restarted.
7695 _db_warn("Too late to set noTTY, enabled on next 'R'!\n") if @_;
7697 $notty = shift if @_;
7703 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
7704 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
7705 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
7706 the value in case a restart is done so we can change it then.
7712 _db_warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_;
7716 } ## end sub ReadLine
7718 =head2 C<RemotePort>
7720 Sets the port that the debugger will try to connect to when starting up.
7721 If the terminal's already been set up, we can't do it, but we remember the
7722 setting in case the user does a restart.
7728 _db_warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
7730 $remoteport = shift if @_;
7732 } ## end sub RemotePort
7736 Checks with the terminal to see if C<Tk> is running, and returns true or
7737 false. Returns false if the current terminal doesn't support C<readline>.
7742 if ( ${ $term->Features }{tkRunning} ) {
7743 return $term->tkRunning(@_);
7747 print $OUT "tkRunning not supported by current ReadLine package.\n";
7750 } ## end sub tkRunning
7754 Sets nonstop mode. If a terminal's already been set up, it's too late; the
7755 debugger remembers the setting in case you restart, though.
7761 _db_warn("Too late to set up NonStop mode, enabled on next 'R'!\n")
7764 $runnonstop = shift if @_;
7766 } ## end sub NonStop
7770 _db_warn("Some flag changes could not take effect until next 'R'!\n")
7773 $^P = parse_DollarCaretP_flags(shift) if @_;
7774 expand_DollarCaretP_flags($^P);
7779 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
7787 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7794 Sets the shell escape command, and generates a printable copy to be used
7801 # If we got an argument, meta-quote it, and add '\b' if it
7802 # ends in a word character.
7804 $sh = quotemeta shift;
7805 $sh .= "\\b" if $sh =~ /\w$/;
7808 # Generate the printable version for the help:
7809 $psh = $sh; # copy it
7810 $psh =~ s/\\b$//; # Take off trailing \b if any
7811 $psh =~ s/\\(.)/$1/g; # De-escape
7812 $psh; # return the printable version
7813 } ## end sub shellBang
7817 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7818 was passed as the argument. (This means you can't override the terminal's
7824 if ( defined $term ) {
7826 # We don't want to show warning backtraces, but we do want die() ones.
7827 local $warnLevel = 0;
7828 local $dieLevel = 1;
7830 # No ornaments if the terminal doesn't support them.
7831 if (not $term->Features->{ornaments}) {
7835 return (eval { $term->ornaments(@_) } || '');
7838 # Use what was passed in if we can't determine it ourselves.
7845 } ## end sub ornaments
7847 =head2 C<recallCommand>
7849 Sets the recall command, and builds a printable version which will appear in
7856 # If there is input, metaquote it. Add '\b' if it ends with a word
7859 $rc = quotemeta shift;
7860 $rc .= "\\b" if $rc =~ /\w$/;
7863 # Build it into a printable version.
7864 $prc = $rc; # Copy it
7865 $prc =~ s/\\b$//; # Remove trailing \b
7866 $prc =~ s/\\(.)/$1/g; # Remove escapes
7867 return $prc; # Return the printable version
7868 } ## end sub recallCommand
7870 =head2 C<LineInfo> - where the line number information goes
7872 Called with no arguments, returns the file or pipe that line info should go to.
7874 Called with an argument (a file or a pipe), it opens that onto the
7875 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7876 file or pipe again to the caller.
7884 # If this is a valid "thing to be opened for output", tack a
7885 # '>' onto the front.
7886 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7888 # If this is a pipe, the stream points to a slave editor.
7889 $slave_editor = ( $stream =~ /^\|/ );
7891 my $new_lineinfo_fh;
7892 # Open it up and unbuffer it.
7893 open ($new_lineinfo_fh , $stream )
7894 or _db_warn("Cannot open '$stream' for write");
7895 $LINEINFO = $new_lineinfo_fh;
7896 _autoflush($LINEINFO);
7900 } ## end sub LineInfo
7902 =head1 COMMAND SUPPORT ROUTINES
7904 These subroutines provide functionality for various commands.
7906 =head2 C<list_modules>
7908 For the C<M> command: list modules loaded and their versions.
7909 Essentially just runs through the keys in %INC, picks each package's
7910 C<$VERSION> variable, gets the file name, and formats the information
7915 sub list_modules { # versions
7919 # keys are the "as-loaded" name, values are the fully-qualified path
7920 # to the file itself.
7922 $file = $_; # get the module name
7923 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7924 s,/,::,g; # change '/' to '::'
7925 s/^perl5db$/DB/; # Special case: debugger
7926 # moves to package DB
7927 s/^Term::ReadLine::readline$/readline/; # simplify readline
7929 # If the package has a $VERSION package global (as all good packages
7930 # should!) decode it and save as partial message.
7931 my $pkg_version = do { no strict 'refs'; ${ $_ . '::VERSION' } };
7932 if ( defined $pkg_version ) {
7933 $version{$file} = "$pkg_version from ";
7936 # Finish up the message with the file the package came from.
7937 $version{$file} .= $INC{$file};
7938 } ## end for (keys %INC)
7940 # Hey, dumpit() formats a hash nicely, so why not use it?
7941 dumpit( $OUT, \%version );
7942 } ## end sub list_modules
7946 Sets up the monster string used to format and print the help.
7948 =head3 HELP MESSAGE FORMAT
7950 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
7951 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
7952 easy to parse and portable, but which still allows the help to be a little
7953 nicer than just plain text.
7955 Essentially, you define the command name (usually marked up with C<< B<> >>
7956 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
7957 newline. The descriptive text can also be marked up in the same way. If you
7958 need to continue the descriptive text to another line, start that line with
7959 just tabs and then enter the marked-up text.
7961 If you are modifying the help text, I<be careful>. The help-string parser is
7962 not very sophisticated, and if you don't follow these rules it will mangle the
7963 help beyond hope until you fix the string.
7967 use vars qw($pre580_help);
7968 use vars qw($pre580_summary);
7972 # XXX: make sure there are tabs between the command and explanation,
7973 # or print_help will screw up your formatting if you have
7974 # eeevil ornaments enabled. This is an insane mess.
7977 Help is currently only available for the new 5.8 command set.
7978 No help is available for the old command set.
7979 We assume you know what you're doing if you switch to it.
7982 B<s> [I<expr>] Single step [in I<expr>].
7983 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7984 <B<CR>> Repeat last B<n> or B<s> command.
7985 B<r> Return from current subroutine.
7986 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7987 at the specified position.
7988 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7989 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7990 B<l> I<line> List single I<line>.
7991 B<l> I<subname> List first window of lines from subroutine.
7992 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7993 B<l> List next window of lines.
7994 B<-> List previous window of lines.
7995 B<v> [I<line>] View window around I<line>.
7996 B<.> Return to the executed line.
7997 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7998 I<filename> may be either the full name of the file, or a regular
7999 expression matching the full file name:
8000 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
8001 Evals (with saved bodies) are considered to be filenames:
8002 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
8003 (in the order of execution).
8004 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
8005 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
8006 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
8007 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
8008 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth).
8009 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
8010 B<b> Sets breakpoint on current line)
8011 B<b> [I<line>] [I<condition>]
8012 Set breakpoint; I<line> defaults to the current execution line;
8013 I<condition> breaks if it evaluates to true, defaults to '1'.
8014 B<b> I<subname> [I<condition>]
8015 Set breakpoint at first line of subroutine.
8016 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
8017 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
8018 B<b> B<postpone> I<subname> [I<condition>]
8019 Set breakpoint at first line of subroutine after
8021 B<b> B<compile> I<subname>
8022 Stop after the subroutine is compiled.
8023 B<B> [I<line>] Delete the breakpoint for I<line>.
8024 B<B> I<*> Delete all breakpoints.
8025 B<a> [I<line>] I<command>
8026 Set an action to be done before the I<line> is executed;
8027 I<line> defaults to the current execution line.
8028 Sequence is: check for breakpoint/watchpoint, print line
8029 if necessary, do action, prompt user if necessary,
8032 B<A> [I<line>] Delete the action for I<line>.
8033 B<A> I<*> Delete all actions.
8034 B<w> I<expr> Add a global watch-expression.
8036 B<W> I<expr> Delete a global watch-expression.
8037 B<W> I<*> Delete all watch-expressions.
8038 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
8039 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
8040 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
8041 B<x> I<expr> Evals expression in list context, dumps the result.
8042 B<m> I<expr> Evals expression in list context, prints methods callable
8043 on the first element of the result.
8044 B<m> I<class> Prints methods callable via the given class.
8045 B<M> Show versions of loaded modules.
8046 B<i> I<class> Prints nested parents of given class.
8047 B<e> Display current thread id.
8048 B<E> Display all thread ids the current one will be identified: <n>.
8049 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8051 B<<> ? List Perl commands to run before each prompt.
8052 B<<> I<expr> Define Perl command to run before each prompt.
8053 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
8054 B<< *> Delete the list of perl commands to run before each prompt.
8055 B<>> ? List Perl commands to run after each prompt.
8056 B<>> I<expr> Define Perl command to run after each prompt.
8057 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
8058 B<>>B< *> Delete the list of Perl commands to run after each prompt.
8059 B<{> I<db_command> Define debugger command to run before each prompt.
8060 B<{> ? List debugger commands to run before each prompt.
8061 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
8062 B<{ *> Delete the list of debugger commands to run before each prompt.
8063 B<$prc> I<number> Redo a previous command (default previous command).
8064 B<$prc> I<-number> Redo number'th-to-last command.
8065 B<$prc> I<pattern> Redo last command that started with I<pattern>.
8066 See 'B<O> I<recallCommand>' too.
8067 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
8072 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
8074 See 'B<O> I<shellBang>' too.
8075 B<source> I<file> Execute I<file> containing debugger commands (may nest).
8076 B<save> I<file> Save current debugger session (actual history) to I<file>.
8077 B<rerun> Rerun session to current position.
8078 B<rerun> I<n> Rerun session to numbered command.
8079 B<rerun> I<-n> Rerun session to number'th-to-last command.
8080 B<H> I<-number> Display last number commands (default all).
8081 B<H> I<*> Delete complete history.
8082 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
8083 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
8084 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well.
8085 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
8086 I<command> Execute as a perl statement in current package.
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> Summary of debugger commands.
8129 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
8130 B<h h> Long help for debugger commands
8131 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
8132 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
8133 Set B<\$DB::doccmd> to change viewer.
8135 Type '|h h' for a paged display if this was too hard to read.
8137 "; # Fix balance of vi % matching: }}}}
8139 # note: tabs in the following section are not-so-helpful
8140 $summary = <<"END_SUM";
8141 I<List/search source lines:> I<Control script execution:>
8142 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8143 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8144 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
8145 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8146 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8147 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
8148 I<Debugger controls:> B<L> List break/watch/actions
8149 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr]
8150 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8151 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
8152 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8153 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
8154 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
8155 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
8156 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8157 B<q> or B<^D> Quit B<R> Attempt a restart
8158 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8159 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8160 B<p> I<expr> Print expression (uses script's current package).
8161 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8162 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8163 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
8164 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8165 B<e> Display thread id B<E> Display all thread ids.
8166 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8169 # ')}}; # Fix balance of vi % matching
8171 # and this is really numb...
8174 B<s> [I<expr>] Single step [in I<expr>].
8175 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
8176 B<CR>> Repeat last B<n> or B<s> command.
8177 B<r> Return from current subroutine.
8178 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
8179 at the specified position.
8180 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
8181 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
8182 B<l> I<line> List single I<line>.
8183 B<l> I<subname> List first window of lines from subroutine.
8184 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
8185 B<l> List next window of lines.
8186 B<-> List previous window of lines.
8187 B<w> [I<line>] List window around I<line>.
8188 B<.> Return to the executed line.
8189 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
8190 I<filename> may be either the full name of the file, or a regular
8191 expression matching the full file name:
8192 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
8193 Evals (with saved bodies) are considered to be filenames:
8194 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
8195 (in the order of execution).
8196 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
8197 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
8198 B<L> List all breakpoints and actions.
8199 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
8200 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) .
8201 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
8202 B<b> [I<line>] [I<condition>]
8203 Set breakpoint; I<line> defaults to the current execution line;
8204 I<condition> breaks if it evaluates to true, defaults to '1'.
8205 B<b> I<subname> [I<condition>]
8206 Set breakpoint at first line of subroutine.
8207 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
8208 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
8209 B<b> B<postpone> I<subname> [I<condition>]
8210 Set breakpoint at first line of subroutine after
8212 B<b> B<compile> I<subname>
8213 Stop after the subroutine is compiled.
8214 B<d> [I<line>] Delete the breakpoint for I<line>.
8215 B<D> Delete all breakpoints.
8216 B<a> [I<line>] I<command>
8217 Set an action to be done before the I<line> is executed;
8218 I<line> defaults to the current execution line.
8219 Sequence is: check for breakpoint/watchpoint, print line
8220 if necessary, do action, prompt user if necessary,
8222 B<a> [I<line>] Delete the action for I<line>.
8223 B<A> Delete all actions.
8224 B<W> I<expr> Add a global watch-expression.
8225 B<W> Delete all watch-expressions.
8226 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
8227 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
8228 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
8229 B<x> I<expr> Evals expression in list context, dumps the result.
8230 B<m> I<expr> Evals expression in list context, prints methods callable
8231 on the first element of the result.
8232 B<m> I<class> Prints methods callable via the given class.
8234 B<<> ? List Perl commands to run before each prompt.
8235 B<<> I<expr> Define Perl command to run before each prompt.
8236 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
8237 B<>> ? List Perl commands to run after each prompt.
8238 B<>> I<expr> Define Perl command to run after each prompt.
8239 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
8240 B<{> I<db_command> Define debugger command to run before each prompt.
8241 B<{> ? List debugger commands to run before each prompt.
8242 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
8243 B<$prc> I<number> Redo a previous command (default previous command).
8244 B<$prc> I<-number> Redo number'th-to-last command.
8245 B<$prc> I<pattern> Redo last command that started with I<pattern>.
8246 See 'B<O> I<recallCommand>' too.
8247 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
8252 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
8254 See 'B<O> I<shellBang>' too.
8255 B<source> I<file> Execute I<file> containing debugger commands (may nest).
8256 B<H> I<-number> Display last number commands (default all).
8257 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
8258 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
8259 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
8260 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
8261 I<command> Execute as a perl statement in current package.
8262 B<v> Show versions of loaded modules.
8263 B<R> Pure-man-restart of debugger, some of debugger state
8264 and command-line options may be lost.
8265 Currently the following settings are preserved:
8266 history, breakpoints and actions, debugger B<O>ptions
8267 and the following command-line options: I<-w>, I<-I>, I<-e>.
8269 B<O> [I<opt>] ... Set boolean option to true
8270 B<O> [I<opt>B<?>] Query options
8271 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
8272 Set options. Use quotes if spaces in value.
8273 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
8274 I<pager> program for output of \"|cmd\";
8275 I<tkRunning> run Tk while prompting (with ReadLine);
8276 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
8277 I<inhibit_exit> Allows stepping off the end of the script.
8278 I<ImmediateStop> Debugger should stop as early as possible.
8279 I<RemotePort> Remote hostname:port for remote debugging
8280 The following options affect what happens with B<V>, B<X>, and B<x> commands:
8281 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
8282 I<compactDump>, I<veryCompact> change style of array and hash dump;
8283 I<globPrint> whether to print contents of globs;
8284 I<DumpDBFiles> dump arrays holding debugged files;
8285 I<DumpPackages> dump symbol tables of packages;
8286 I<DumpReused> dump contents of \"reused\" addresses;
8287 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
8288 I<bareStringify> Do not print the overload-stringified value;
8289 Other options include:
8290 I<PrintRet> affects printing of return value after B<r> command,
8291 I<frame> affects printing messages on subroutine entry/exit.
8292 I<AutoTrace> affects printing messages on possible breaking points.
8293 I<maxTraceLen> gives max length of evals/args listed in stack trace.
8294 I<ornaments> affects screen appearance of the command line.
8295 I<CreateTTY> bits control attempts to create a new TTY on events:
8296 1: on fork() 2: debugger is started inside debugger
8298 During startup options are initialized from \$ENV{PERLDB_OPTS}.
8299 You can put additional initialization options I<TTY>, I<noTTY>,
8300 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
8301 B<R> after you set them).
8303 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
8304 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
8305 B<h h> Summary of debugger commands.
8306 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
8307 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
8308 Set B<\$DB::doccmd> to change viewer.
8310 Type '|h' for a paged display if this was too hard to read.
8312 "; # Fix balance of vi % matching: }}}}
8314 # note: tabs in the following section are not-so-helpful
8315 $pre580_summary = <<"END_SUM";
8316 I<List/search source lines:> I<Control script execution:>
8317 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8318 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8319 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
8320 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8321 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8322 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
8323 I<Debugger controls:> B<L> List break/watch/actions
8324 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
8325 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8326 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
8327 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8328 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
8329 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
8330 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8331 B<q> or B<^D> Quit B<R> Attempt a restart
8332 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8333 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8334 B<p> I<expr> Print expression (uses script's current package).
8335 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8336 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8337 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
8338 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8339 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8342 # ')}}; # Fix balance of vi % matching
8344 } ## end sub sethelp
8346 =head2 C<print_help()>
8348 Most of what C<print_help> does is just text formatting. It finds the
8349 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
8350 terminal control characters to simulate them (courtesy of
8351 C<Term::ReadLine::TermCap>).
8356 my $help_str = shift;
8358 # Restore proper alignment destroyed by eeevil I<> and B<>
8359 # ornaments: A pox on both their houses!
8361 # A help command will have everything up to and including
8362 # the first tab sequence padded into a field 16 (or if indented 20)
8363 # wide. If it's wider than that, an extra space will be added.
8365 ^ # only matters at start of line
8366 ( \040{4} | \t )* # some subcommands are indented
8367 ( < ? # so <CR> works
8368 [BI] < [^\t\n] + ) # find an eeevil ornament
8369 ( \t+ ) # original separation, discarded
8370 ( .* ) # this will now start (no earlier) than
8373 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
8374 my $clean = $command;
8375 $clean =~ s/[BI]<([^>]*)>/$1/g;
8377 # replace with this whole string:
8378 ($leadwhite ? " " x 4 : "")
8380 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
8385 $help_str =~ s{ # handle bold ornaments
8386 B < ( [^>] + | > ) >
8388 $Term::ReadLine::TermCap::rl_term_set[2]
8390 . $Term::ReadLine::TermCap::rl_term_set[3]
8393 $help_str =~ s{ # handle italic ornaments
8394 I < ( [^>] + | > ) >
8396 $Term::ReadLine::TermCap::rl_term_set[0]
8398 . $Term::ReadLine::TermCap::rl_term_set[1]
8402 print {$OUT} $help_str;
8405 } ## end sub print_help
8409 This routine does a lot of gyrations to be sure that the pager is C<less>.
8410 It checks for C<less> masquerading as C<more> and records the result in
8411 C<$fixed_less> so we don't have to go through doing the stats again.
8415 use vars qw($fixed_less);
8418 if ($pager =~ /\bless\b/)
8422 elsif ($pager =~ /\bmore\b/)
8424 # Nope, set to more. See what's out there.
8425 my @st_more = stat('/usr/bin/more');
8426 my @st_less = stat('/usr/bin/less');
8428 # is it really less, pretending to be more?
8432 && $st_more[0] == $st_less[0]
8433 && $st_more[1] == $st_less[1]
8443 # We already know if this is set.
8444 return if $fixed_less;
8446 # changes environment!
8447 # 'r' added so we don't do (slow) stats again.
8448 $fixed_less = 1 if _calc_is_less();
8451 } ## end sub fix_less
8453 =head1 DIE AND WARN MANAGEMENT
8457 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
8458 to debug a debugger problem.
8460 It does its best to report the error that occurred, and then forces the
8461 program, debugger, and everything to die.
8467 # No entry/exit messages.
8470 # No return value prints.
8473 # set the abort signal handling to the default (just terminate).
8474 $SIG{'ABRT'} = 'DEFAULT';
8476 # If we enter the signal handler recursively, kill myself with an
8477 # abort signal (so we just terminate).
8478 kill 'ABRT', $$ if $panic++;
8480 # If we can show detailed info, do so.
8481 if ( defined &Carp::longmess ) {
8483 # Don't recursively enter the warn handler, since we're carping.
8484 local $SIG{__WARN__} = '';
8486 # Skip two levels before reporting traceback: we're skipping
8487 # mydie and confess.
8488 local $Carp::CarpLevel = 2; # mydie + confess
8490 # Tell us all about it.
8491 _db_warn( Carp::longmess("Signal @_") );
8494 # No Carp. Tell us about the signal as best we can.
8497 print $DB::OUT "Got signal @_\n";
8502 } ## end sub diesignal
8506 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
8507 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
8513 # No entry/exit trace.
8516 # No return value printing.
8519 # Turn off warn and die handling to prevent recursive entries to this
8521 local $SIG{__WARN__} = '';
8522 local $SIG{__DIE__} = '';
8524 # Load Carp if we can. If $^S is false (current thing being compiled isn't
8525 # done yet), we may not be able to do a require.
8526 eval { require Carp }
8527 if defined $^S; # If error/warning during compilation,
8528 # require may be broken.
8530 # Use the core warn() unless Carp loaded OK.
8532 "\nCannot print stack trace, load with -MCarp option to see stack" ),
8534 unless defined &Carp::longmess;
8536 # Save the current values of $single and $trace, and then turn them off.
8537 my ( $mysingle, $mytrace ) = ( $single, $trace );
8541 # We can call Carp::longmess without its being "debugged" (which we
8542 # don't want - we just want to use it!). Capture this for later.
8543 my $mess = Carp::longmess(@_);
8545 # Restore $single and $trace to their original values.
8546 ( $single, $trace ) = ( $mysingle, $mytrace );
8548 # Use the debugger's own special way of printing warnings to print
8549 # the stack trace message.
8555 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
8556 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
8557 single stepping and tracing during the call to C<Carp::longmess> to avoid
8558 debugging it - we just want to use it.
8560 If C<dieLevel> is zero, we let the program being debugged handle the
8561 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
8562 the debugger takes over all exception handling, printing a backtrace and
8563 displaying the exception via its C<dbwarn()> routine.
8570 local $SIG{__DIE__} = '';
8571 local $SIG{__WARN__} = '';
8572 if ( $dieLevel > 2 ) {
8573 local $SIG{__WARN__} = \&dbwarn;
8574 _db_warn(@_); # Yell no matter what
8577 if ( $dieLevel < 2 ) {
8578 die @_ if $^S; # in eval propagate
8581 # The code used to check $^S to see if compilation of the current thing
8582 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
8583 eval { require Carp };
8586 "\nCannot print stack trace, load with -MCarp option to see stack" )
8587 unless defined &Carp::longmess;
8589 # We do not want to debug this chunk (automatic disabling works
8590 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
8591 # get the stack trace from Carp::longmess (if possible), restore $signal
8592 # and $trace, and then die with the stack trace.
8593 my ( $mysingle, $mytrace ) = ( $single, $trace );
8599 package Carp; # Do not include us in the list
8600 eval { $mess = Carp::longmess(@_); };
8602 ( $single, $trace ) = ( $mysingle, $mytrace );
8606 =head2 C<warnlevel()>
8608 Set the C<$DB::warnLevel> variable that stores the value of the
8609 C<warnLevel> option. Calling C<warnLevel()> with a positive value
8610 results in the debugger taking over all warning handlers. Setting
8611 C<warnLevel> to zero leaves any warning handlers set up by the program
8612 being debugged in place.
8618 my $prevwarn = $SIG{__WARN__} unless $warnLevel;
8621 $SIG{__WARN__} = \&DB::dbwarn;
8624 $SIG{__WARN__} = $prevwarn;
8626 undef $SIG{__WARN__};
8630 } ## end sub warnLevel
8634 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
8635 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
8636 zero lets you use your own C<die()> handler.
8643 my $prevdie = $SIG{__DIE__} unless $dieLevel;
8647 # Always set it to dbdie() for non-zero values.
8648 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
8650 # No longer exists, so don't try to use it.
8651 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
8653 # If we've finished initialization, mention that stack dumps
8654 # are enabled, If dieLevel is 1, we won't stack dump if we die
8656 print $OUT "Stack dump during die enabled",
8657 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
8660 # XXX This is probably obsolete, given that diehard() is gone.
8661 print $OUT "Dump printed too.\n" if $dieLevel > 2;
8662 } ## end if ($dieLevel)
8664 # Put the old one back if there was one.
8666 $SIG{__DIE__} = $prevdie;
8667 print $OUT "Default die handler restored.\n";
8669 undef $SIG{__DIE__};
8670 print $OUT "Die handler removed.\n";
8674 } ## end sub dieLevel
8676 =head2 C<signalLevel>
8678 Number three in a series: set C<signalLevel> to zero to keep your own
8679 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
8680 takes over and handles them with C<DB::diesignal()>.
8686 my $prevsegv = $SIG{SEGV} unless $signalLevel;
8687 my $prevbus = $SIG{BUS} unless $signalLevel;
8688 $signalLevel = shift;
8690 $SIG{SEGV} = \&DB::diesignal;
8691 $SIG{BUS} = \&DB::diesignal;
8694 $SIG{SEGV} = $prevsegv;
8695 $SIG{BUS} = $prevbus;
8699 } ## end sub signalLevel
8701 =head1 SUBROUTINE DECODING SUPPORT
8703 These subroutines are used during the C<x> and C<X> commands to try to
8704 produce as much information as possible about a code reference. They use
8705 L<Devel::Peek> to try to find the glob in which this code reference lives
8706 (if it does) - this allows us to actually code references which correspond
8707 to named subroutines (including those aliased via glob assignment).
8709 =head2 C<CvGV_name()>
8711 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
8712 via that routine. If this fails, return the reference again (when the
8713 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
8719 my $name = CvGV_name_or_bust($in);
8720 defined $name ? $name : $in;
8723 =head2 C<CvGV_name_or_bust> I<coderef>
8725 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
8726 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
8727 find a glob for this ref.
8729 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
8733 use vars qw($skipCvGV);
8735 sub CvGV_name_or_bust {
8737 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
8738 return unless ref $in;
8739 $in = \&$in; # Hard reference...
8740 eval { require Devel::Peek; 1 } or return;
8741 my $gv = Devel::Peek::CvGV($in) or return;
8742 *$gv{PACKAGE} . '::' . *$gv{NAME};
8743 } ## end sub CvGV_name_or_bust
8747 A utility routine used in various places; finds the file where a subroutine
8748 was defined, and returns that filename and a line-number range.
8750 Tries to use C<@sub> first; if it can't find it there, it tries building a
8751 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
8752 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
8753 this way, it brute-force searches C<%sub>, checking for identical references.
8757 sub _find_sub_helper {
8760 return unless defined &$subr;
8761 my $name = CvGV_name_or_bust($subr);
8763 $data = $sub{$name} if defined $name;
8764 return $data if defined $data;
8767 $subr = \&$subr; # Hard reference
8770 $s = $_, last if $subr eq \&$_;
8785 return ( $sub{$subr} || _find_sub_helper($subr) );
8786 } ## end sub find_sub
8790 A subroutine that uses the utility function C<methods_via> to find all the
8791 methods in the class corresponding to the current reference and in
8800 # Figure out the class - either this is the class or it's a reference
8801 # to something blessed into that class.
8803 $class = ref $class if ref $class;
8807 # Show the methods that this class has.
8808 methods_via( $class, '', 1 );
8810 # Show the methods that UNIVERSAL has.
8811 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
8812 } ## end sub methods
8814 =head2 C<methods_via($class, $prefix, $crawl_upward)>
8816 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
8817 all the parent class methods. C<$class> is the name of the next class to
8818 try; C<$prefix> is the message prefix, which gets built up as we go up the
8819 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
8820 higher in the C<@ISA> tree, 0 if we should stop.
8826 # If we've processed this class already, just quit.
8828 return if $seen{$class}++;
8830 # This is a package that is contributing the methods we're about to print.
8832 my $prepend = $prefix ? "via $prefix: " : '';
8835 # Extract from all the symbols in this class.
8836 my $class_ref = do { no strict "refs"; \%{$class . '::'} };
8837 while (my ($name, $glob) = each %$class_ref) {
8838 # references directly in the symbol table are Proxy Constant
8839 # Subroutines, and are by their very nature defined
8840 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8841 # to a subroutine reference, which can be tested by defined.
8842 # $glob might also be the value -1 (from sub foo;)
8843 # or (say) '$$' (from sub foo ($$);)
8844 # \$glob will be SCALAR in both cases.
8845 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8846 && !$seen{$name}++) {
8847 push @to_print, "$prepend$name\n";
8854 print $DB::OUT $_ foreach sort @to_print;
8857 # If the $crawl_upward argument is false, just quit here.
8858 return unless shift;
8860 # $crawl_upward true: keep going up the tree.
8861 # Find all the classes this one is a subclass of.
8862 my $class_ISA_ref = do { no strict "refs"; \@{"${class}::ISA"} };
8863 for my $name ( @$class_ISA_ref ) {
8865 # Set up the new prefix.
8866 $prepend = $prefix ? $prefix . " -> $name" : $name;
8868 # Crawl up the tree and keep trying to crawl up.
8869 methods_via( $name, $prepend, 1 );
8871 } ## end sub methods_via
8873 =head2 C<setman> - figure out which command to use to show documentation
8875 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8880 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|NetWare)\z/s
8881 ? "man" # O Happy Day!
8882 : "perldoc"; # Alas, poor unfortunates
8885 =head2 C<runman> - run the appropriate command to show documentation
8887 Accepts a man page name; runs the appropriate command to display it (set up
8888 during debugger initialization). Uses C<_db_system()> to avoid mucking up the
8889 program's STDIN and STDOUT.
8893 my %_is_in_pods = (map { $_ => 1 }
9029 _db_system("$doccmd $doccmd");
9033 # this way user can override, like with $doccmd="man -Mwhatever"
9034 # or even just "man " to disable the path check.
9035 if ( $doccmd ne 'man' ) {
9036 _db_system("$doccmd $page");
9040 $page = 'perl' if lc($page) eq 'help';
9043 my $man1dir = $Config::Config{'man1dir'};
9044 my $man3dir = $Config::Config{'man3dir'};
9045 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
9047 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
9048 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
9049 chop $manpath if $manpath;
9051 # harmless if missing, I figure
9052 my $oldpath = $ENV{MANPATH};
9053 $ENV{MANPATH} = $manpath if $manpath;
9054 my $nopathopt = $^O =~ /dunno what goes here/;
9059 # I just *know* there are men without -M
9060 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
9065 unless ( $page =~ /^perl\w/ ) {
9066 # do it this way because its easier to slurp in to keep up to date - clunky though.
9067 if (exists($_is_in_pods{$page})) {
9068 CORE::system( $doccmd,
9069 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
9073 } ## end if (CORE::system($doccmd...
9074 if ( defined $oldpath ) {
9075 $ENV{MANPATH} = $manpath;
9078 delete $ENV{MANPATH};
9082 #use Carp; # This did break, left for debugging
9084 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
9086 Because of the way the debugger interface to the Perl core is designed, any
9087 debugger package globals that C<DB::sub()> requires have to be defined before
9088 any subroutines can be called. These are defined in the second C<BEGIN> block.
9090 This block sets things up so that (basically) the world is sane
9091 before the debugger starts executing. We set up various variables that the
9092 debugger has to have set up before the Perl core starts running:
9098 The debugger's own filehandles (copies of STD and STDOUT for now).
9102 Characters for shell escapes, the recall command, and the history command.
9106 The maximum recursion depth.
9110 The size of a C<w> command's window.
9114 The before-this-line context to be printed in a C<v> (view a window around this line) command.
9118 The fact that we're not in a sub at all right now.
9122 The default SIGINT handler for the debugger.
9126 The appropriate value of the flag in C<$^D> that says the debugger is running
9130 The current debugger recursion level
9134 The list of postponed items and the C<$single> stack (XXX define this)
9138 That we want no return values and no subroutine entry/exit trace.
9144 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
9146 use vars qw($db_stop);
9148 BEGIN { # This does not compile, alas. (XXX eh?)
9149 $IN = \*STDIN; # For bugs before DB::OUT has been opened
9150 $OUT = \*STDERR; # For errors before DB::OUT has been opened
9152 # Define characters used by command parsing.
9153 $sh = '!'; # Shell escape (does not work)
9154 $rc = ','; # Recall command (does not work)
9155 @hist = ('?'); # Show history (does not work)
9156 @truehist = (); # Can be saved for replay (per session)
9158 # This defines the point at which you get the 'deep recursion'
9159 # warning. It MUST be defined or the debugger will not load.
9162 # Number of lines around the current one that are shown in the
9166 # How much before-the-current-line context the 'v' command should
9167 # use in calculating the start of the window it will display.
9170 # We're not in any sub yet, but we need this to be a defined value.
9173 # Set up the debugger's interrupt handler. It simply sets a flag
9174 # ($signal) that DB::DB() will check before each command is executed.
9175 $SIG{INT} = \&DB::catch;
9177 # The following lines supposedly, if uncommented, allow the debugger to
9178 # debug itself. Perhaps we can try that someday.
9179 # This may be enabled to debug debugger:
9180 #$warnLevel = 1 unless defined $warnLevel;
9181 #$dieLevel = 1 unless defined $dieLevel;
9182 #$signalLevel = 1 unless defined $signalLevel;
9184 # This is the flag that says "a debugger is running, please call
9185 # DB::DB and DB::sub". We will turn it on forcibly before we try to
9186 # execute anything in the user's context, because we always want to
9188 $db_stop = 0; # Compiler warning ...
9189 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
9191 # This variable records how many levels we're nested in debugging. Used
9192 # Used in the debugger prompt, and in determining whether it's all over or
9194 $level = 0; # Level of recursive debugging
9196 # "Triggers bug (?) in perl if we postpone this until runtime."
9197 # XXX No details on this yet, or whether we should fix the bug instead
9198 # of work around it. Stay tuned.
9201 # Used to track the current stack depth using the auto-stacked-variable
9203 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
9205 # Don't print return values on exiting a subroutine.
9208 # No extry/exit tracing.
9213 BEGIN { $^W = $ini_warn; } # Switch warnings back
9215 =head1 READLINE SUPPORT - COMPLETION FUNCTION
9219 C<readline> support - adds command completion to basic C<readline>.
9221 Returns a list of possible completions to C<readline> when invoked. C<readline>
9222 will print the longest common substring following the text already entered.
9224 If there is only a single possible completion, C<readline> will use it in full.
9226 This code uses C<map> and C<grep> heavily to create lists of possible
9227 completion. Think LISP in this section.
9233 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
9234 # $text is the text to be completed.
9235 # $line is the incoming line typed by the user.
9236 # $start is the start of the text to be completed in the incoming line.
9237 my ( $text, $line, $start ) = @_;
9239 # Save the initial text.
9240 # The search pattern is current package, ::, extract the next qualifier
9241 # Prefix and pack are set to undef.
9242 my ( $itext, $search, $prefix, $pack ) =
9243 ( $text, "^\Q${package}::\E([^:]+)\$" );
9245 =head3 C<b postpone|compile>
9251 Find all the subroutines that might match in this package
9255 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
9259 Include all the rest of the subs that are known
9263 C<grep> out the ones that match the text we have so far
9267 Return this as the list of possible completions
9273 return sort grep /^\Q$text/, ( keys %sub ),
9274 qw(postpone load compile), # subroutines
9275 ( map { /$search/ ? ($1) : () } keys %sub )
9276 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
9280 Get all the possible files from C<@INC> as it currently stands and
9281 select the ones that match the text so far.
9285 return sort grep /^\Q$text/, values %INC # files
9286 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
9288 =head3 C<V> (list variable) and C<m> (list modules)
9290 There are two entry points for these commands:
9292 =head4 Unqualified package names
9294 Get the top-level packages and grab everything that matches the text
9295 so far. For each match, recursively complete the partial packages to
9296 get all possible matching packages. Return this sorted list.
9300 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9301 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
9302 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
9304 =head4 Qualified package names
9306 Take a partially-qualified package and find all subpackages for it
9307 by getting all the subpackages for the package so far, matching all
9308 the subpackages against the text, and discarding all of them which
9309 start with 'main::'. Return this list.
9313 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9314 grep !/^main::/, grep /^\Q$text/,
9315 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () }
9316 do { no strict 'refs'; keys %{ $prefix . '::' } }
9317 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
9318 and $text =~ /^(.*[^:])::?(\w*)$/
9321 =head3 C<f> - switch files
9323 Here, we want to get a fully-qualified filename for the C<f> command.
9328 =item 1. The original source file itself
9330 =item 2. A file from C<@INC>
9332 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
9338 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
9339 # We might possibly want to switch to an eval (which has a "filename"
9340 # like '(eval 9)'), so we may need to clean up the completion text
9341 # before proceeding.
9342 $prefix = length($1) - length($text);
9347 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
9348 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
9349 out of C<%main::>, add the initial source file, and extract the ones that
9350 match the completion text so far.
9355 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
9357 } ## end if ($line =~ /^\|*f\s+(.*)/)
9359 =head3 Subroutine name completion
9361 We look through all of the defined subs (the keys of C<%sub>) and
9362 return both all the possible matches to the subroutine name plus
9363 all the matches qualified to the current package.
9367 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
9368 $text = substr $text, 1;
9370 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
9372 map { /$search/ ? ($1) : () }
9375 } ## end if ((substr $text, 0, ...
9377 =head3 Scalar, array, and hash completion: partially qualified package
9379 Much like the above, except we have to do a little more cleanup:
9383 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
9391 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
9395 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
9401 Figure out the prefix vs. what needs completing.
9405 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
9412 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
9418 map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
9426 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.
9430 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9431 return db_complete( $out[0], $line, $start );
9434 # Return the list of possibles.
9437 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
9443 =head3 Symbol completion: current package or package C<main>.
9447 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
9454 If it's C<main>, delete main to just get C<::> leading.
9458 $pack = ( $package eq 'main' ? '' : $package ) . '::';
9464 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
9468 $prefix = substr $text, 0, 1;
9469 $text = substr $text, 1;
9477 We look for the lexical scope above DB::DB and auto-complete lexical variables
9478 if PadWalker could be loaded.
9482 if (not $text =~ /::/ and eval { require PadWalker } ) {
9485 my @info = caller($level);
9489 last if $info[3] eq 'DB::DB';
9492 my $lexicals = PadWalker::peek_my($level);
9493 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
9501 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
9505 push @out, map "$prefix$_", grep /^\Q$text/,
9506 ( grep /^_?[a-zA-Z]/, keys %$pack ),
9507 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
9511 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
9517 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9518 return db_complete( $out[0], $line, $start );
9521 # Return the list of possibles.
9523 } ## end if ($text =~ /^[\$@%]/)
9527 We use C<option_val()> to look up the current value of the option. If there's
9528 only a single value, we complete the command in such a way that it is a
9529 complete command for setting the option in question. If there are multiple
9530 possible values, we generate a command consisting of the option plus a trailing
9531 question mark, which, if executed, will list the current value of the option.
9535 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
9536 { # Options after space
9537 # We look for the text to be matched in the list of possible options,
9538 # and fetch the current value.
9539 my @out = grep /^\Q$text/, @options;
9540 my $val = option_val( $out[0], undef );
9542 # Set up a 'query option's value' command.
9544 if ( not defined $val or $val =~ /[\n\r]/ ) {
9546 # There's really nothing else we can do.
9549 # We have a value. Create a proper option-setting command.
9550 elsif ( $val =~ /\s/ ) {
9552 # XXX This may be an extraneous variable.
9555 # We'll want to quote the string (because of the embedded
9556 # whtespace), but we want to make sure we don't end up with
9557 # mismatched quote characters. We try several possibilities.
9558 foreach my $l ( split //, qq/\"\'\#\|/ ) {
9560 # If we didn't find this quote character in the value,
9561 # quote it using this quote character.
9562 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
9564 } ## end elsif ($val =~ /\s/)
9566 # Don't need any quotes.
9571 # If there were multiple possible values, return '? ', which
9572 # makes the command into a query command. If there was just one,
9573 # have readline append that.
9574 $rl_attribs->{completer_terminator_character} =
9575 ( @out == 1 ? $out : '? ' );
9577 # Return list of possibilities.
9579 } ## end if ((substr $line, 0, ...
9581 =head3 Filename completion
9583 For entering filenames. We simply call C<readline>'s C<filename_list()>
9584 method with the completion text to get the possible completions.
9588 return $term->filename_list($text); # filenames
9590 } ## end sub db_complete
9592 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
9594 Functions that possibly ought to be somewhere else.
9604 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n";
9609 If we have $ini_pids, save it in the environment; else remove it from the
9610 environment. Used by the C<R> (restart) command.
9615 if ( defined($ini_pids) ) {
9616 $ENV{PERLDB_PIDS} = $ini_pids;
9619 delete( $ENV{PERLDB_PIDS} );
9621 } ## end sub clean_ENV
9623 # PERLDBf_... flag names from perl.h
9624 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
9627 %DollarCaretP_flags = (
9628 PERLDBf_SUB => 0x01, # Debug sub enter/exit
9629 PERLDBf_LINE => 0x02, # Keep line #
9630 PERLDBf_NOOPT => 0x04, # Switch off optimizations
9631 PERLDBf_INTER => 0x08, # Preserve more data
9632 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
9633 PERLDBf_SINGLE => 0x20, # Start with single-step on
9634 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
9635 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
9636 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
9637 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
9638 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
9639 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
9641 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
9642 # doesn't need to set it. It's provided for the benefit of profilers and
9643 # other code analysers.
9645 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
9648 sub parse_DollarCaretP_flags {
9653 foreach my $f ( split /\s*\|\s*/, $flags ) {
9655 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
9658 elsif ( $f =~ /^(\d+)$/ ) {
9661 elsif ( $f =~ /^DEFAULT$/i ) {
9662 $value = $DollarCaretP_flags{PERLDB_ALL};
9665 $f =~ /^(?:PERLDBf_)?(.*)$/i;
9666 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
9667 unless ( defined $value ) {
9669 "Unrecognized \$^P flag '$f'!\n",
9670 "Acceptable flags are: "
9671 . join( ', ', sort keys %DollarCaretP_flags ),
9672 ", and hexadecimal and decimal numbers.\n"
9682 sub expand_DollarCaretP_flags {
9683 my $DollarCaretP = shift;
9686 my $n = ( 1 << $_ );
9687 ( $DollarCaretP & $n )
9688 ? ( $DollarCaretP_flags_r{$n}
9689 || sprintf( '0x%x', $n ) )
9693 return @bits ? join( '|', @bits ) : 0;
9700 Rerun the current session to:
9702 rerun current position
9704 rerun 4 command number 4
9706 rerun -4 current command minus 4 (go back 4 steps)
9708 Whether this always makes sense, in the current context is unknowable, and is
9709 in part left as a useful exercise for the reader. This sub returns the
9710 appropriate arguments to rerun the current session.
9717 pop(@truehist); # strim
9718 unless (defined $truehist[$i]) {
9719 print "Unable to return to non-existent command: $i\n";
9721 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
9722 my @temp = @truehist; # store
9723 push(@DB::typeahead, @truehist); # saved
9724 @truehist = @hist = (); # flush
9725 @args = restart(); # setup
9726 get_list("PERLDB_HIST"); # clean
9727 set_list("PERLDB_HIST", @temp); # reset
9734 Restarting the debugger is a complex operation that occurs in several phases.
9735 First, we try to reconstruct the command line that was used to invoke Perl
9741 # I may not be able to resurrect you, but here goes ...
9743 "Warning: some settings and command-line options may be lost!\n";
9744 my ( @script, @flags, $cl );
9746 # If warn was on before, turn it on again.
9747 push @flags, '-w' if $ini_warn;
9749 # Rebuild the -I flags that were on the initial
9752 push @flags, '-I', $_;
9755 # Turn on taint if it was on before.
9756 push @flags, '-T' if ${^TAINT};
9758 # Arrange for setting the old INC:
9759 # Save the current @init_INC in the environment.
9760 set_list( "PERLDB_INC", @ini_INC );
9762 # If this was a perl one-liner, go to the "file"
9763 # corresponding to the one-liner read all the lines
9764 # out of it (except for the first one, which is going
9765 # to be added back on again when 'perl -d' runs: that's
9766 # the 'require perl5db.pl;' line), and add them back on
9767 # to the command line to be executed.
9769 my $lines = *{$main::{'_<-e'}}{ARRAY};
9770 for ( 1 .. $#$lines ) { # The first line is PERL5DB
9771 chomp( $cl = $lines->[$_] );
9772 push @script, '-e', $cl;
9774 } ## end if ($0 eq '-e')
9776 # Otherwise we just reuse the original name we had
9784 After the command line has been reconstructed, the next step is to save
9785 the debugger's status in environment variables. The C<DB::set_list> routine
9786 is used to save aggregate variables (both hashes and arrays); scalars are
9787 just popped into environment variables directly.
9791 # If the terminal supported history, grab it and
9792 # save that in the environment.
9793 set_list( "PERLDB_HIST",
9794 $term->Features->{getHistory}
9798 # Find all the files that were visited during this
9799 # session (i.e., the debugger had magic hashes
9800 # corresponding to them) and stick them in the environment.
9801 my @had_breakpoints = keys %had_breakpoints;
9802 set_list( "PERLDB_VISITED", @had_breakpoints );
9804 # Save the debugger options we chose.
9805 set_list( "PERLDB_OPT", %option );
9806 # set_list( "PERLDB_OPT", options2remember() );
9808 # Save the break-on-loads.
9809 set_list( "PERLDB_ON_LOAD", %break_on_load );
9813 The most complex part of this is the saving of all of the breakpoints. They
9814 can live in an awful lot of places, and we have to go through all of them,
9815 find the breakpoints, and then save them in the appropriate environment
9816 variable via C<DB::set_list>.
9820 # Go through all the breakpoints and make sure they're
9823 for ( 0 .. $#had_breakpoints ) {
9825 # We were in this file.
9826 my $file = $had_breakpoints[$_];
9828 # Grab that file's magic line hash.
9829 *dbline = $main::{ '_<' . $file };
9831 # Skip out if it doesn't exist, or if the breakpoint
9832 # is in a postponed file (we'll do postponed ones
9834 next unless %dbline or $postponed_file{$file};
9836 # In an eval. This is a little harder, so we'll
9837 # do more processing on that below.
9838 ( push @hard, $file ), next
9839 if $file =~ /^\(\w*eval/;
9841 # XXX I have no idea what this is doing. Yet.
9843 @add = %{ $postponed_file{$file} }
9844 if $postponed_file{$file};
9846 # Save the list of all the breakpoints for this file.
9847 set_list( "PERLDB_FILE_$_", %dbline, @add );
9849 # Serialize the extra data %breakpoints_data hash.
9851 set_list( "PERLDB_FILE_ENABLED_$_",
9852 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 }
9853 sort { $a <=> $b } keys(%dbline)
9855 } ## end for (0 .. $#had_breakpoints)
9857 # The breakpoint was inside an eval. This is a little
9858 # more difficult. XXX and I don't understand it.
9859 foreach my $hard_file (@hard) {
9860 # Get over to the eval in question.
9861 *dbline = $main::{ '_<' . $hard_file };
9862 my $quoted = quotemeta $hard_file;
9864 for my $sub ( keys %sub ) {
9865 if (my ($n1, $n2) = $sub{$sub} =~ /\A$quoted:(\d+)-(\d+)\z/) {
9866 $subs{$sub} = [ $n1, $n2 ];
9871 "No subroutines in $hard_file, ignoring breakpoints.\n";
9874 LINES: foreach my $line ( keys %dbline ) {
9876 # One breakpoint per sub only:
9877 my ( $offset, $found );
9878 SUBS: foreach my $sub ( keys %subs ) {
9880 $subs{$sub}->[1] >= $line # Not after the subroutine
9882 not defined $offset # Not caught
9888 $offset = $line - $subs{$sub}->[0];
9890 $offset = "+$offset";
9893 } ## end if ($subs{$sub}->[1] >=...
9894 } ## end for $sub (keys %subs)
9895 if ( defined $offset ) {
9896 $postponed{$found} =
9897 "break $offset if $dbline{$line}";
9901 ("Breakpoint in ${hard_file}:$line ignored:"
9902 . " after all the subroutines.\n");
9904 } ## end for $line (keys %dbline)
9905 } ## end for (@hard)
9907 # Save the other things that don't need to be
9909 set_list( "PERLDB_POSTPONE", %postponed );
9910 set_list( "PERLDB_PRETYPE", @$pretype );
9911 set_list( "PERLDB_PRE", @$pre );
9912 set_list( "PERLDB_POST", @$post );
9913 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9915 # We are officially restarting.
9916 $ENV{PERLDB_RESTART} = 1;
9918 # We are junking all child debuggers.
9919 delete $ENV{PERLDB_PIDS}; # Restore ini state
9921 # Set this back to the initial pid.
9922 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9926 After all the debugger status has been saved, we take the command we built up
9927 and then return it, so we can C<exec()> it. The debugger will spot the
9928 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9929 from the environment.
9933 # And run Perl again. Add the "-d" flag, all the
9934 # flags we built up, the script (whether a one-liner
9935 # or a file), add on the -emacs flag for a slave editor,
9936 # and then the old arguments.
9938 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9944 =head1 END PROCESSING - THE C<END> BLOCK
9946 Come here at the very end of processing. We want to go into a
9947 loop where we allow the user to enter commands and interact with the
9948 debugger, but we don't want anything else to execute.
9950 First we set the C<$finished> variable, so that some commands that
9951 shouldn't be run after the end of program quit working.
9953 We then figure out whether we're truly done (as in the user entered a C<q>
9954 command, or we finished execution while running nonstop). If we aren't,
9955 we set C<$single> to 1 (causing the debugger to get control again).
9957 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9958 message and returns control to the debugger. Repeat.
9960 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9961 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9962 break, run to completion.).
9967 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9968 $fall_off_end = 1 unless $inhibit_exit;
9970 # Do not stop in at_exit() and destructors on exit:
9971 if ($fall_off_end or $runnonstop) {
9975 DB::fake::at_exit();
9979 =head1 PRE-5.8 COMMANDS
9981 Some of the commands changed function quite a bit in the 5.8 command
9982 realignment, so much so that the old code had to be replaced completely.
9983 Because we wanted to retain the option of being able to go back to the
9984 former command set, we moved the old code off to this section.
9986 There's an awful lot of duplicated code here. We've duplicated the
9987 comments to keep things clear.
9991 Does nothing. Used to I<turn off> commands.
9995 sub cmd_pre580_null {
10000 =head2 Old C<a> command.
10002 This version added actions if you supplied them, and deleted them
10011 # Argument supplied. Add the action.
10012 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
10014 # If the line isn't there, use the current line.
10015 my $i = $1 || $line;
10018 # If there is an action ...
10021 # ... but the line isn't breakable, skip it.
10022 if ( $dbline[$i] == 0 ) {
10023 print $OUT "Line $i may not have an action.\n";
10027 # ... and the line is breakable:
10028 # Mark that there's an action in this file.
10029 $had_breakpoints{$filename} |= 2;
10031 # Delete any current action.
10032 $dbline{$i} =~ s/\0[^\0]*//;
10034 # Add the new action, continuing the line as needed.
10035 $dbline{$i} .= "\0" . action($j);
10037 } ## end if (length $j)
10039 # No action supplied.
10042 # Delete the action.
10043 $dbline{$i} =~ s/\0[^\0]*//;
10045 # Mark as having no break or action if nothing's left.
10046 delete $dbline{$i} if $dbline{$i} eq '';
10048 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
10049 } ## end sub cmd_pre580_a
10051 =head2 Old C<b> command
10060 my $dbline = shift;
10063 if ( $cmd =~ /^load\b\s*(.*)/ ) {
10069 # b compile|postpone <some sub> [<condition>]
10070 # The interpreter actually traps this one for us; we just put the
10071 # necessary condition in the %postponed hash.
10072 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
10074 # Capture the condition if there is one. Make it true if none.
10075 my $cond = length $3 ? $3 : '1';
10077 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
10078 # if it was 'compile'.
10079 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
10081 # De-Perl4-ify the name - ' separators to ::.
10082 $subname =~ s/\'/::/g;
10084 # Qualify it into the current package unless it's already qualified.
10085 $subname = "${package}::" . $subname
10086 unless $subname =~ /::/;
10088 # Add main if it starts with ::.
10089 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
10091 # Save the break type for this sub.
10092 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
10093 } ## end elsif ($cmd =~ ...
10095 # b <sub name> [<condition>]
10096 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
10098 my $cond = length $2 ? $2 : '1';
10099 cmd_b_sub( $subname, $cond );
10101 # b <line> [<condition>].
10102 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
10103 my $i = $1 || $dbline;
10104 my $cond = length $2 ? $2 : '1';
10105 cmd_b_line( $i, $cond );
10107 } ## end sub cmd_pre580_b
10109 =head2 Old C<D> command.
10111 Delete all breakpoints unconditionally.
10118 if ( $cmd =~ /^\s*$/ ) {
10119 print $OUT "Deleting all breakpoints...\n";
10121 # %had_breakpoints lists every file that had at least one
10122 # breakpoint in it.
10124 for $file ( keys %had_breakpoints ) {
10126 # Switch to the desired file temporarily.
10127 local *dbline = $main::{ '_<' . $file };
10132 # For all lines in this file ...
10133 for my $i (1 .. $max) {
10135 # If there's a breakpoint or action on this line ...
10136 if ( defined $dbline{$i} ) {
10138 # ... remove the breakpoint.
10139 $dbline{$i} =~ s/^[^\0]+//;
10140 if ( $dbline{$i} =~ s/^\0?$// ) {
10142 # Remove the entry altogether if no action is there.
10143 delete $dbline{$i};
10145 } ## end if (defined $dbline{$i...
10146 } ## end for my $i (1 .. $max)
10148 # If, after we turn off the "there were breakpoints in this file"
10149 # bit, the entry in %had_breakpoints for this file is zero,
10150 # we should remove this file from the hash.
10151 if ( not $had_breakpoints{$file} &= ~1 ) {
10152 delete $had_breakpoints{$file};
10154 } ## end for $file (keys %had_breakpoints)
10156 # Kill off all the other breakpoints that are waiting for files that
10157 # haven't been loaded yet.
10159 undef %postponed_file;
10160 undef %break_on_load;
10161 } ## end if ($cmd =~ /^\s*$/)
10162 } ## end sub cmd_pre580_D
10164 =head2 Old C<h> command
10166 Print help. Defaults to printing the long-form help; the 5.8 version
10167 prints the summary by default.
10175 # Print the *right* help, long format.
10176 if ( $cmd =~ /^\s*$/ ) {
10177 print_help($pre580_help);
10180 # 'h h' - explicitly-requested summary.
10181 elsif ( $cmd =~ /^h\s*/ ) {
10182 print_help($pre580_summary);
10185 # Find and print a command's help.
10186 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
10187 my $asked = $1; # for proper errmsg
10188 my $qasked = quotemeta($asked); # for searching
10189 # XXX: finds CR but not <CR>
10193 (?:[IB]<) # Optional markup
10194 $qasked # The command name
10201 ( # The command help:
10203 (?:[IB]<) # Optional markup
10204 $qasked # The command name
10205 ([\s\S]*?) # Lines starting with tabs
10209 ) # Line not starting with space
10210 # (Next command's help)
10214 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
10218 print_help("B<$asked> is not a debugger command.\n");
10220 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
10221 } ## end sub cmd_pre580_h
10223 =head2 Old C<W> command
10225 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
10233 # Delete all watch expressions.
10234 if ( $cmd =~ /^$/ ) {
10236 # No watching is going on.
10239 # Kill all the watch expressions and values.
10240 @to_watch = @old_watch = ();
10243 # Add a watch expression.
10244 elsif ( $cmd =~ /^(.*)/s ) {
10246 # add it to the list to be watched.
10247 push @to_watch, $1;
10249 # Get the current value of the expression.
10250 # Doesn't handle expressions returning list values!
10252 my ($val) = DB::eval();
10253 $val = ( defined $val ) ? "'$val'" : 'undef';
10256 push @old_watch, $val;
10258 # We're watching stuff.
10261 } ## end elsif ($cmd =~ /^(.*)/s)
10262 } ## end sub cmd_pre580_W
10264 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
10266 The debugger used to have a bunch of nearly-identical code to handle
10267 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
10268 C<cmd_prepost> unify all this into one set of code to handle the
10269 appropriate actions.
10271 =head2 C<cmd_pre590_prepost>
10273 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
10274 do something destructive. In pre 5.8 debuggers, the default action was to
10275 delete all the actions.
10279 sub cmd_pre590_prepost {
10281 my $line = shift || '*';
10282 my $dbline = shift;
10284 return cmd_prepost( $cmd, $line, $dbline );
10285 } ## end sub cmd_pre590_prepost
10287 =head2 C<cmd_prepost>
10289 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
10290 Since the lists of actions are all held in arrays that are pointed to by
10291 references anyway, all we have to do is pick the right array reference and
10292 then use generic code to all, delete, or list actions.
10299 # No action supplied defaults to 'list'.
10300 my $line = shift || '?';
10302 # Figure out what to put in the prompt.
10305 # Make sure we have some array or another to address later.
10306 # This means that if ssome reason the tests fail, we won't be
10307 # trying to stash actions or delete them from the wrong place.
10310 # < - Perl code to run before prompt.
10311 if ( $cmd =~ /^\</o ) {
10312 $which = 'pre-perl';
10316 # > - Perl code to run after prompt.
10317 elsif ( $cmd =~ /^\>/o ) {
10318 $which = 'post-perl';
10322 # { - first check for properly-balanced braces.
10323 elsif ( $cmd =~ /^\{/o ) {
10324 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
10326 "$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n";
10329 # Properly balanced. Pre-prompt debugger actions.
10331 $which = 'pre-debugger';
10334 } ## end elsif ( $cmd =~ /^\{/o )
10336 # Did we find something that makes sense?
10338 print $OUT "Confused by command: $cmd\n";
10345 if ( $line =~ /^\s*\?\s*$/o ) {
10348 # Nothing there. Complain.
10349 print $OUT "No $which actions.\n";
10353 # List the actions in the selected list.
10354 print $OUT "$which commands:\n";
10355 foreach my $action (@$aref) {
10356 print $OUT "\t$cmd -- $action\n";
10359 } ## end if ( $line =~ /^\s*\?\s*$/o)
10361 # Might be a delete.
10363 if ( length($cmd) == 1 ) {
10364 if ( $line =~ /^\s*\*\s*$/o ) {
10366 # It's a delete. Get rid of the old actions in the
10369 print $OUT "All $cmd actions cleared.\n";
10373 # Replace all the actions. (This is a <, >, or {).
10374 @$aref = action($line);
10376 } ## end if ( length($cmd) == 1)
10377 elsif ( length($cmd) == 2 ) {
10379 # Add the action to the line. (This is a <<, >>, or {{).
10380 push @$aref, action($line);
10384 # <<<, >>>>, {{{{{{ ... something not a command.
10386 "Confused by strange length of $which command($cmd)...\n";
10388 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
10390 } ## end sub cmd_prepost
10394 Contains the C<at_exit> routine that the debugger uses to issue the
10395 C<Debugged program terminated ...> message after the program completes. See
10396 the C<END> block documentation for more details.
10403 "Debugged program terminated. Use 'q' to quit or 'R' to restart.";
10406 package DB; # Do not trace this 1; below!