4 perl5db.pl - the perl debugger
8 perl -d your_Perl_script
12 C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
13 you invoke a script with C<perl -d>. This documentation tries to outline the
14 structure and services provided by C<perl5db.pl>, and to describe how you
19 The debugger can look pretty forbidding to many Perl programmers. There are
20 a number of reasons for this, many stemming out of the debugger's history.
22 When the debugger was first written, Perl didn't have a lot of its nicer
23 features - no references, no lexical variables, no closures, no object-oriented
24 programming. So a lot of the things one would normally have done using such
25 features was done using global variables, globs and the C<local()> operator
28 Some of these have survived into the current debugger; a few of the more
29 interesting and still-useful idioms are noted in this section, along with notes
30 on the comments themselves.
32 =head2 Why not use more lexicals?
34 Experienced Perl programmers will note that the debugger code tends to use
35 mostly package globals rather than lexically-scoped variables. This is done
36 to allow a significant amount of control of the debugger from outside the
39 Unfortunately, though the variables are accessible, they're not well
40 documented, so it's generally been a decision that hasn't made a lot of
41 difference to most users. Where appropriate, comments have been added to
42 make variables more accessible and usable, with the understanding that these
43 I<are> debugger internals, and are therefore subject to change. Future
44 development should probably attempt to replace the globals with a well-defined
45 API, but for now, the variables are what we've got.
47 =head2 Automated variable stacking via C<local()>
49 As you may recall from reading C<perlfunc>, the C<local()> operator makes a
50 temporary copy of a variable in the current scope. When the scope ends, the
51 old copy is restored. This is often used in the debugger to handle the
52 automatic stacking of variables during recursive calls:
57 # Do some stuff, then ...
61 What happens is that on entry to the subroutine, C<$some_global> is localized,
62 then altered. When the subroutine returns, Perl automatically undoes the
63 localization, restoring the previous value. Voila, automatic stack management.
65 The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
66 which lets the debugger get control inside of C<eval>'ed code. The debugger
67 localizes a saved copy of C<$@> inside the subroutine, which allows it to
68 keep C<$@> safe until it C<DB::eval> returns, at which point the previous
69 value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
70 track of C<$@> inside C<eval>s which C<eval> other C<eval's>.
72 In any case, watch for this pattern. It occurs fairly often.
76 This is used to cleverly reverse the sense of a logical test depending on
77 the value of an auxiliary variable. For instance, the debugger's C<S>
78 (search for subroutines by pattern) allows you to negate the pattern
81 # Find all non-'foo' subs:
84 Boolean algebra states that the truth table for XOR looks like this:
90 (! not present and no match) --> false, don't print
94 (! not present and matches) --> true, print
98 (! present and no match) --> true, print
102 (! present and matches) --> false, don't print
106 As you can see, the first pair applies when C<!> isn't supplied, and
107 the second pair applies when it is. The XOR simply allows us to
108 compact a more complicated if-then-elseif-else into a more elegant
109 (but perhaps overly clever) single test. After all, it needed this
112 =head2 FLAGS, FLAGS, FLAGS
114 There is a certain C programming legacy in the debugger. Some variables,
115 such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed
116 of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
117 of state to be stored independently in a single scalar.
123 is checking to see if the appropriate bit is on. Since each bit can be
124 "addressed" independently in this way, C<$scalar> is acting sort of like
125 an array of bits. Obviously, since the contents of C<$scalar> are just a
126 bit-pattern, we can save and restore it easily (it will just look like
129 The problem, is of course, that this tends to leave magic numbers scattered
130 all over your program whenever a bit is set, cleared, or checked. So why do
137 First, doing an arithmetical or bitwise operation on a scalar is
138 just about the fastest thing you can do in Perl: C<use constant> actually
139 creates a subroutine call, and array and hash lookups are much slower. Is
140 this over-optimization at the expense of readability? Possibly, but the
141 debugger accesses these variables a I<lot>. Any rewrite of the code will
142 probably have to benchmark alternate implementations and see which is the
143 best balance of readability and speed, and then document how it actually
148 Second, it's very easy to serialize a scalar number. This is done in
149 the restart code; the debugger state variables are saved in C<%ENV> and then
150 restored when the debugger is restarted. Having them be just numbers makes
155 Third, some of these variables are being shared with the Perl core
156 smack in the middle of the interpreter's execution loop. It's much faster for
157 a C program (like the interpreter) to check a bit in a scalar than to access
158 several different variables (or a Perl array).
162 =head2 What are those C<XXX> comments for?
164 Any comment containing C<XXX> means that the comment is either somewhat
165 speculative - it's not exactly clear what a given variable or chunk of
166 code is doing, or that it is incomplete - the basics may be clear, but the
167 subtleties are not completely documented.
169 Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
171 =head1 DATA STRUCTURES MAINTAINED BY CORE
173 There are a number of special data structures provided to the debugger by
174 the Perl interpreter.
176 The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline>
177 via glob assignment) contains the text from C<$filename>, with each
178 element corresponding to a single line of C<$filename>. Additionally,
179 breakable lines will be dualvars with the numeric component being the
180 memory address of a COP node. Non-breakable lines are dualvar to 0.
182 The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
183 assignment) contains breakpoints and actions. The keys are line numbers;
184 you can set individual values, but not the whole hash. The Perl interpreter
185 uses this hash to determine where breakpoints have been set. Any true value is
186 considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
187 Values are magical in numeric context: 1 if the line is breakable, 0 if not.
189 The scalar C<${"_<$filename"}> simply contains the string C<$filename>.
190 This is also the case for evaluated strings that contain subroutines, or
191 which are currently being executed. The $filename for C<eval>ed strings looks
194 =head1 DEBUGGER STARTUP
196 When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
197 non-interactive sessions, C<.perldb> for interactive ones) that can set a number
198 of options. In addition, this file may define a subroutine C<&afterinit>
199 that will be executed (in the debugger's context) after the debugger has
202 Next, it checks the C<PERLDB_OPTS> environment variable and treats its
203 contents as the argument of a C<o> command in the debugger.
205 =head2 STARTUP-ONLY OPTIONS
207 The following options can only be specified at startup.
208 To set them in your rcfile, add a call to
209 C<&parse_options("optionName=new_value")>.
215 the TTY to use for debugging i/o.
219 if set, goes in NonStop mode. On interrupt, if TTY is not set,
220 uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
221 Term::Rendezvous. Current variant is to have the name of TTY in this
226 if false, a dummy ReadLine is used, so you can debug
227 ReadLine applications.
231 if true, no i/o is performed until interrupt.
235 file or pipe to print line number info to. If it is a
236 pipe, a short "emacs like" message is used.
240 host:port to connect to on remote host for remote debugging.
244 file to store session history to. There is no default and so no
245 history file is written unless this variable is explicitly set.
249 number of commands to store to the file specified in C<HistFile>.
256 &parse_options("NonStop=1 LineInfo=db.out");
257 sub afterinit { $trace = 1; }
259 The script will run without human intervention, putting trace
260 information into C<db.out>. (If you interrupt it, you had better
261 reset C<LineInfo> to something I<interactive>!)
263 =head1 INTERNALS DESCRIPTION
265 =head2 DEBUGGER INTERFACE VARIABLES
267 Perl supplies the values for C<%sub>. It effectively inserts
268 a C<&DB::DB();> in front of each place that can have a
269 breakpoint. At each subroutine call, it calls C<&DB::sub> with
270 C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
271 {require 'perl5db.pl'}> before the first line.
273 After each C<require>d file is compiled, but before it is executed, a
274 call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
275 is the expanded name of the C<require>d file (as found via C<%INC>).
277 =head3 IMPORTANT INTERNAL VARIABLES
281 Used to control when the debugger will attempt to acquire another TTY to be
286 =item * 1 - on C<fork()>
288 =item * 2 - debugger is started inside debugger
290 =item * 4 - on startup
296 The value -2 indicates that no return value should be printed.
297 Any other positive value causes C<DB::sub> to print return values.
301 The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
302 contents of C<@_> when C<DB::eval> is called.
306 Determines what messages (if any) will get printed when a subroutine (or eval)
307 is entered or exited.
311 =item * 0 - No enter/exit messages
313 =item * 1 - Print I<entering> messages on subroutine entry
315 =item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
317 =item * 4 - Extended messages: C<< <in|out> I<context>=I<fully-qualified sub name> from I<file>:I<line> >>. If no other flag is on, acts like 1+4.
319 =item * 8 - Adds parameter information to messages, and overloaded stringify and tied FETCH is enabled on the printed arguments. Ignored if C<4> is not on.
321 =item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is not on.
325 To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
326 The debugger internally juggles the value of C<$frame> during execution to
327 protect external modules that the debugger uses from getting traced.
331 Tracks current debugger nesting level. Used to figure out how many
332 C<E<lt>E<gt>> pairs to surround the line number with when the debugger
333 outputs a prompt. Also used to help determine if the program has finished
334 during command parsing.
336 =head4 C<$onetimeDump>
338 Controls what (if anything) C<DB::eval()> will print after evaluating an
343 =item * C<undef> - don't print anything
345 =item * C<dump> - use C<dumpvar.pl> to display the value returned
347 =item * C<methods> - print the methods callable on the first item returned
351 =head4 C<$onetimeDumpDepth>
353 Controls how far down C<dumpvar.pl> will go before printing C<...> while
354 dumping a structure. Numeric. If C<undef>, print all levels.
358 Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
359 which is called before every statement, checks this and puts the user into
360 command mode if it finds C<$signal> set to a true value.
364 Controls behavior during single-stepping. Stacked in C<@stack> on entry to
365 each subroutine; popped again at the end of each subroutine.
369 =item * 0 - run continuously.
371 =item * 1 - single-step, go into subs. The C<s> command.
373 =item * 2 - single-step, don't go into subs. The C<n> command.
375 =item * 4 - print current sub depth (turned on to force this when C<too much
382 Controls the output of trace information.
386 =item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
388 =item * 2 - watch expressions are active
390 =item * 4 - user defined a C<watchfunction()> in C<afterinit()>
394 =head4 C<$slave_editor>
396 1 if C<LINEINFO> was directed to a pipe; 0 otherwise.
400 Stack of filehandles that C<DB::readline()> will read commands from.
401 Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
405 Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
406 supplied by the Perl interpreter to the debugger. Contains the source.
410 Previous values of watch expressions. First set when the expression is
411 entered; reset whenever the watch expression changes.
415 Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
416 so that the debugger can substitute safe values while it's running, and
417 restore them when it returns control.
421 Saves the current value of C<$single> on entry to a subroutine.
422 Manipulated by the C<c> command to turn off tracing in all subs above the
427 The 'watch' expressions: to be evaluated before each line is executed.
431 The typeahead buffer, used by C<DB::readline>.
435 Command aliases. Stored as character strings to be substituted for a command
438 =head4 C<%break_on_load>
440 Keys are file names, values are 1 (break when this file is loaded) or undef
441 (don't break when it is loaded).
445 Keys are line numbers, values are C<condition\0action>. If used in numeric
446 context, values are 0 if not breakable, 1 if breakable, no matter what is
447 in the actual hash entry.
449 =head4 C<%had_breakpoints>
451 Keys are file names; values are bitfields:
455 =item * 1 - file has a breakpoint in it.
457 =item * 2 - file has an action in it.
461 A zero or undefined value means this file has neither.
465 Stores the debugger options. These are character string values.
469 Saves breakpoints for code that hasn't been compiled yet.
470 Keys are subroutine names, values are:
474 =item * C<compile> - break when this sub is compiled
476 =item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
480 =head4 C<%postponed_file>
482 This hash keeps track of breakpoints that need to be set for files that have
483 not yet been compiled. Keys are filenames; values are references to hashes.
484 Each of these hashes is keyed by line number, and its values are breakpoint
485 definitions (C<condition\0action>).
487 =head1 DEBUGGER INITIALIZATION
489 The debugger's initialization actually jumps all over the place inside this
490 package. This is because there are several BEGIN blocks (which of course
491 execute immediately) spread through the code. Why is that?
493 The debugger needs to be able to change some things and set some things up
494 before the debugger code is compiled; most notably, the C<$deep> variable that
495 C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
496 debugger has to turn off warnings while the debugger code is compiled, but then
497 restore them to their original setting before the program being debugged begins
500 The first C<BEGIN> block simply turns off warnings by saving the current
501 setting of C<$^W> and then setting it to zero. The second one initializes
502 the debugger variables that are needed before the debugger begins executing.
503 The third one puts C<$^X> back to its former value.
505 We'll detail the second C<BEGIN> block later; just remember that if you need
506 to initialize something before the debugger starts really executing, that's
519 BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
523 $^V =~ /^v(\d+\.\d+)/;
524 feature->import(":$1");
525 $_initial_cwd = Cwd::getcwd();
528 # Debugger for Perl 5.00x; perl5db.pl patch level:
529 use vars qw($VERSION $header);
531 $VERSION = '1.49_01';
533 $header = "perl5db.pl version $VERSION";
535 =head1 DEBUGGER ROUTINES
539 This function replaces straight C<eval()> inside the debugger; it simplifies
540 the process of evaluating code in the user's context.
542 The code to be evaluated is passed via the package global variable
543 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
545 Before we do the C<eval()>, we preserve the current settings of C<$trace>,
546 C<$single>, C<$^D> and C<$usercontext>. The latter contains the
547 preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
548 user's current package, grabbed when C<DB::DB> got control. This causes the
549 proper context to be used when the eval is actually done. Afterward, we
550 restore C<$trace>, C<$single>, and C<$^D>.
552 Next we need to handle C<$@> without getting confused. We save C<$@> in a
553 local lexical, localize C<$saved[0]> (which is where C<save()> will put
554 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
555 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
556 considered sane by the debugger. If there was an C<eval()> error, we print
557 it on the debugger's output. If C<$onetimedump> is defined, we call
558 C<dumpit> if it's set to 'dump', or C<methods> if it's set to
559 'methods'. Setting it to something else causes the debugger to do the eval
560 but not print the result - handy if you want to do something else with it
561 (the "watch expressions" code does this to get the value of the watch
562 expression but not show it unless it matters).
564 In any case, we then return the list of output from C<eval> to the caller,
565 and unwinding restores the former version of C<$@> in C<@saved> as well
566 (the localization of C<$saved[0]> goes away at the end of this scope).
568 =head3 Parameters and variables influencing execution of DB::eval()
570 C<DB::eval> isn't parameterized in the standard way; this is to keep the
571 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
572 The variables listed below influence C<DB::eval()>'s execution directly.
576 =item C<$evalarg> - the thing to actually be eval'ed
578 =item C<$trace> - Current state of execution tracing
580 =item C<$single> - Current state of single-stepping
582 =item C<$onetimeDump> - what is to be displayed after the evaluation
584 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
588 The following variables are altered by C<DB::eval()> during its execution. They
589 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
593 =item C<@res> - used to capture output from actual C<eval>.
595 =item C<$otrace> - saved value of C<$trace>.
597 =item C<$osingle> - saved value of C<$single>.
599 =item C<$od> - saved value of C<$^D>.
601 =item C<$saved[0]> - saved value of C<$@>.
603 =item $\ - for output of C<$@> if there is an evaluation error.
607 =head3 The problem of lexicals
609 The context of C<DB::eval()> presents us with some problems. Obviously,
610 we want to be 'sandboxed' away from the debugger's internals when we do
611 the eval, but we need some way to control how punctuation variables and
612 debugger globals are used.
614 We can't use local, because the code inside C<DB::eval> can see localized
615 variables; and we can't use C<my> either for the same reason. The code
616 in this routine compromises and uses C<my>.
618 After this routine is over, we don't have user code executing in the debugger's
619 context, so we can use C<my> freely.
623 ############################################## Begin lexical danger zone
625 # 'my' variables used here could leak into (that is, be visible in)
626 # the context that the code being evaluated is executing in. This means that
627 # the code could modify the debugger's variables.
629 # Fiddling with the debugger's context could be Bad. We insulate things as
694 # Used to save @ARGV and extract any debugger-related flags.
697 # Used to prevent multiple entries to diesignal()
698 # (if for instance diesignal() itself dies)
701 # Used to prevent the debugger from running nonstop
705 sub _calc_usercontext {
708 # Cancel strict completely for the evaluated code, so the code
709 # the user evaluates won't be affected by it. (Shlomi Fish)
710 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
711 . "package $package;"; # this won't let them modify, alas
716 # 'my' would make it visible from user code
717 # but so does local! --tchrist
718 # Remember: this localizes @DB::res, not @main::res.
722 # Try to keep the user code from messing with us. Save these so that
723 # even if the eval'ed code changes them, we can put them back again.
724 # Needed because the user could refer directly to the debugger's
725 # package globals (and any 'my' variables in this containing scope)
726 # inside the eval(), and we want to try to stay safe.
727 local $otrace = $trace;
728 local $osingle = $single;
731 # Untaint the incoming eval() argument.
732 { ($evalarg) = $evalarg =~ /(.*)/s; }
734 # $usercontext built in DB::DB near the comment
735 # "set up the context for DB::eval ..."
736 # Evaluate and save any results.
737 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
739 # Restore those old values.
745 # Save the current value of $@, and preserve it in the debugger's copy
746 # of the saved precious globals.
749 # Since we're only saving $@, we only have to localize the array element
750 # that it will be stored in.
751 local $saved[0]; # Preserve the old value of $@
754 # Now see whether we need to report an error back to the user.
760 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
761 # are package globals.
762 elsif ($onetimeDump) {
763 if ( $onetimeDump eq 'dump' ) {
764 local $option{dumpDepth} = $onetimedumpDepth
765 if defined $onetimedumpDepth;
766 dumpit( $OUT, \@res );
768 elsif ( $onetimeDump eq 'methods' ) {
771 } ## end elsif ($onetimeDump)
775 ############################################## End lexical danger zone
777 # After this point it is safe to introduce lexicals.
778 # The code being debugged will be executing in its own context, and
779 # can't see the inside of the debugger.
781 # However, one should not overdo it: leave as much control from outside as
782 # possible. If you make something a lexical, it's not going to be addressable
783 # from outside the debugger even if you know its name.
785 # This file is automatically included if you do perl -d.
786 # It's probably not useful to include this yourself.
788 # Before venturing further into these twisty passages, it is
789 # wise to read the perldebguts man page or risk the ire of dragons.
791 # (It should be noted that perldebguts will tell you a lot about
792 # the underlying mechanics of how the debugger interfaces into the
793 # Perl interpreter, but not a lot about the debugger itself. The new
794 # comments in this code try to address this problem.)
796 # Note that no subroutine call is possible until &DB::sub is defined
797 # (for subroutines defined outside of the package DB). In fact the same is
798 # true if $deep is not defined.
800 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
802 # modified Perl debugger, to be run from Emacs in perldb-mode
803 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
804 # Johan Vromans -- upgrade to 4.0 pl 10
805 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
806 ########################################################################
808 =head1 DEBUGGER INITIALIZATION
810 The debugger starts up in phases.
814 First, it initializes the environment it wants to run in: turning off
815 warnings during its own compilation, defining variables which it will need
816 to avoid warnings later, setting itself up to not exit when the program
817 terminates, and defaulting to printing return values for the C<r> command.
821 # Needed for the statement after exec():
823 # This BEGIN block is simply used to switch off warnings during debugger
824 # compilation. Probably it would be better practice to fix the warnings,
825 # but this is how it's done at the moment.
830 } # Switch compilation warnings off until another BEGIN.
832 local ($^W) = 0; # Switch run-time warnings off during init.
834 =head2 THREADS SUPPORT
836 If we are running under a threaded Perl, we require threads and threads::shared
837 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
838 threaded debugger control. C<-dt> can also be used to set this.
840 Each new thread will be announced and the debugger prompt will always inform
841 you of each new thread created. It will also indicate the thread id in which
842 we are currently running within the prompt like this:
846 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
847 command prompt. The prompt will show: C<[0]> when running under threads, but
848 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
850 While running under threads, when you set or delete a breakpoint (etc.), this
851 will apply to all threads, not just the currently running one. When you are
852 in a currently executing thread, you will stay there until it completes. With
853 the current implementation it is not currently possible to hop from one thread
856 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
858 Note that threading support was built into the debugger as of Perl version
859 C<5.8.6> and debugger version C<1.2.8>.
864 # ensure we can share our non-threaded variables or no-op
865 if ($ENV{PERL5DB_THREADED}) {
867 require threads::shared;
868 import threads::shared qw(share);
872 print "Threads support enabled\n";
875 *share = sub(\[$@%]) {};
879 # These variables control the execution of 'dumpvar.pl'.
894 # used to control die() reporting in diesignal()
897 use vars qw($CarpLevel);
900 # without threads, $filename is not defined until DB::DB is called
901 share($main::{'_<'.$filename}) if defined $filename;
903 # Command-line + PERLLIB:
904 # Save the contents of @INC before they are modified elsewhere.
907 # This was an attempt to clear out the previous values of various
908 # trapped errors. Apparently it didn't help. XXX More info needed!
909 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
911 # We set these variables to safe values. We don't want to blindly turn
912 # off warnings, because other packages may still want them.
913 $trace = $signal = $single = 0; # Uninitialized warning suppression
914 # (local $^W cannot help - other packages!).
916 # Default to not exiting when program finishes; print the return
917 # value when the 'r' command is used to return from a subroutine.
918 $inhibit_exit = $option{PrintRet} = 1;
920 use vars qw($trace_to_depth);
922 # Default to 1E9 so it won't be limited to a certain recursion depth.
923 $trace_to_depth = 1E9;
925 =head1 OPTION PROCESSING
927 The debugger's options are actually spread out over the debugger itself and
928 C<dumpvar.pl>; some of these are variables to be set, while others are
929 subs to be called with a value. To try to make this a little easier to
930 manage, the debugger uses a few data structures to define what options
931 are legal and how they are to be processed.
933 First, the C<@options> array defines the I<names> of all the options that
939 CommandSet HistFile HistSize
940 hashDepth arrayDepth dumpDepth
941 DumpDBFiles DumpPackages DumpReused
942 compactDump veryCompact quote
943 HighBit undefPrint globPrint
944 PrintRet UsageOnly frame
946 ReadLine NonStop LineInfo
947 maxTraceLen recallCommand ShellBang
948 pager tkRunning ornaments
949 signalLevel warnLevel dieLevel
950 inhibit_exit ImmediateStop bareStringify
951 CreateTTY RemotePort windowSize
955 @RememberOnROptions = qw(DollarCaretP);
959 Second, C<optionVars> lists the variables that each option uses to save its
964 use vars qw(%optionVars);
967 hashDepth => \$dumpvar::hashDepth,
968 arrayDepth => \$dumpvar::arrayDepth,
969 CommandSet => \$CommandSet,
970 DumpDBFiles => \$dumpvar::dumpDBFiles,
971 DumpPackages => \$dumpvar::dumpPackages,
972 DumpReused => \$dumpvar::dumpReused,
973 HighBit => \$dumpvar::quoteHighBit,
974 undefPrint => \$dumpvar::printUndef,
975 globPrint => \$dumpvar::globPrint,
976 UsageOnly => \$dumpvar::usageOnly,
977 CreateTTY => \$CreateTTY,
978 bareStringify => \$dumpvar::bareStringify,
980 AutoTrace => \$trace,
981 inhibit_exit => \$inhibit_exit,
982 maxTraceLen => \$maxtrace,
983 ImmediateStop => \$ImmediateStop,
984 RemotePort => \$remoteport,
985 windowSize => \$window,
986 HistFile => \$histfile,
987 HistSize => \$histsize,
992 Third, C<%optionAction> defines the subroutine to be called to process each
997 use vars qw(%optionAction);
1000 compactDump => \&dumpvar::compactDump,
1001 veryCompact => \&dumpvar::veryCompact,
1002 quote => \&dumpvar::quote,
1005 ReadLine => \&ReadLine,
1006 NonStop => \&NonStop,
1007 LineInfo => \&LineInfo,
1008 recallCommand => \&recallCommand,
1009 ShellBang => \&shellBang,
1011 signalLevel => \&signalLevel,
1012 warnLevel => \&warnLevel,
1013 dieLevel => \&dieLevel,
1014 tkRunning => \&tkRunning,
1015 ornaments => \&ornaments,
1016 RemotePort => \&RemotePort,
1017 DollarCaretP => \&DollarCaretP,
1022 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1027 # Note that this list is not complete: several options not listed here
1028 # actually require that dumpvar.pl be loaded for them to work, but are
1029 # not in the table. A subsequent patch will correct this problem; for
1030 # the moment, we're just recommenting, and we are NOT going to change
1032 use vars qw(%optionRequire);
1035 compactDump => 'dumpvar.pl',
1036 veryCompact => 'dumpvar.pl',
1037 quote => 'dumpvar.pl',
1042 There are a number of initialization-related variables which can be set
1043 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1044 variable. These are:
1048 =item C<$rl> - readline control XXX needs more explanation
1050 =item C<$warnLevel> - whether or not debugger takes over warning handling
1052 =item C<$dieLevel> - whether or not debugger takes over die handling
1054 =item C<$signalLevel> - whether or not debugger takes over signal handling
1056 =item C<$pre> - preprompt actions (array reference)
1058 =item C<$post> - postprompt actions (array reference)
1062 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1064 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1070 # These guys may be defined in $ENV{PERL5DB} :
1071 $rl = 1 unless defined $rl;
1072 $warnLevel = 1 unless defined $warnLevel;
1073 $dieLevel = 1 unless defined $dieLevel;
1074 $signalLevel = 1 unless defined $signalLevel;
1075 $pre = [] unless defined $pre;
1076 $post = [] unless defined $post;
1077 $pretype = [] unless defined $pretype;
1078 $CreateTTY = 3 unless defined $CreateTTY;
1079 $CommandSet = '580' unless defined $CommandSet;
1084 share($signalLevel);
1094 The default C<die>, C<warn>, and C<signal> handlers are set up.
1098 warnLevel($warnLevel);
1099 dieLevel($dieLevel);
1100 signalLevel($signalLevel);
1104 The pager to be used is needed next. We try to get it from the
1105 environment first. If it's not defined there, we try to find it in
1106 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1107 then call the C<pager()> function to save the pager name.
1111 # This routine makes sure $pager is set up so that '|' can use it.
1114 # If PAGER is defined in the environment, use it.
1118 # If not, see if Config.pm defines it.
1119 : eval { require Config }
1120 && defined $Config::Config{pager}
1121 ? $Config::Config{pager}
1123 # If not, fall back to 'more'.
1126 unless defined $pager;
1130 We set up the command to be used to access the man pages, the command
1131 recall character (C<!> unless otherwise defined) and the shell escape
1132 character (C<!> unless otherwise defined). Yes, these do conflict, and
1133 neither works in the debugger at the moment.
1139 # Set up defaults for command recall and shell escape (note:
1140 # these currently don't work in linemode debugging).
1141 recallCommand("!") unless defined $prc;
1142 shellBang("!") unless defined $psh;
1146 We then set up the gigantic string containing the debugger help.
1147 We also set the limit on the number of arguments we'll display during a
1154 # If we didn't get a default for the length of eval/stack trace args,
1156 $maxtrace = 400 unless defined $maxtrace;
1158 =head2 SETTING UP THE DEBUGGER GREETING
1160 The debugger I<greeting> helps to inform the user how many debuggers are
1161 running, and whether the current debugger is the primary or a child.
1163 If we are the primary, we just hang onto our pid so we'll have it when
1164 or if we start a child debugger. If we are a child, we'll set things up
1165 so we'll have a unique greeting and so the parent will give us our own
1168 We save the current contents of the C<PERLDB_PIDS> environment variable
1169 because we mess around with it. We'll also need to hang onto it because
1170 we'll need it if we restart.
1172 Child debuggers make a label out of the current PID structure recorded in
1173 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1174 yet so the parent will give them one later via C<resetterm()>.
1178 # Save the current contents of the environment; we're about to
1179 # much with it. We'll need this if we have to restart.
1180 use vars qw($ini_pids);
1181 $ini_pids = $ENV{PERLDB_PIDS};
1183 use vars qw ($pids $term_pid);
1185 if ( defined $ENV{PERLDB_PIDS} ) {
1187 # We're a child. Make us a label out of the current PID structure
1188 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1189 # a term yet so the parent will give us one later via resetterm().
1191 my $env_pids = $ENV{PERLDB_PIDS};
1192 $pids = "[$env_pids]";
1194 # Unless we are on OpenVMS, all programs under the DCL shell run under
1197 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1201 $ENV{PERLDB_PIDS} .= "->$$";
1205 } ## end if (defined $ENV{PERLDB_PIDS...
1208 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1209 # child debugger, and mark us as the parent, so we'll know to set up
1210 # more TTY's is we have to.
1211 $ENV{PERLDB_PIDS} = "$$";
1216 use vars qw($pidprompt);
1219 # Sets up $emacs as a synonym for $slave_editor.
1220 our ($slave_editor);
1221 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1223 =head2 READING THE RC FILE
1225 The debugger will read a file of initialization options if supplied. If
1226 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1230 # As noted, this test really doesn't check accurately that the debugger
1231 # is running at a terminal or not.
1233 use vars qw($rcfile);
1235 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1236 # this is the wrong metric!
1237 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
1242 The debugger does a safety test of the file to be read. It must be owned
1243 either by the current user or root, and must only be writable by the owner.
1247 # This wraps a safety test around "do" to read and evaluate the init file.
1249 # This isn't really safe, because there's a race
1250 # between checking and opening. The solution is to
1251 # open and fstat the handle, but then you have to read and
1252 # eval the contents. But then the silly thing gets
1253 # your lexical scope, which is unfortunate at best.
1257 # Just exactly what part of the word "CORE::" don't you understand?
1258 local $SIG{__WARN__};
1259 local $SIG{__DIE__};
1261 unless ( is_safe_file($file) ) {
1262 CORE::warn <<EO_GRIPE;
1263 perldb: Must not source insecure rcfile $file.
1264 You or the superuser must be the owner, and it must not
1265 be writable by anyone but its owner.
1268 } ## end unless (is_safe_file($file...
1271 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1272 } ## end sub safe_do
1274 # This is the safety test itself.
1276 # Verifies that owner is either real user or superuser and that no
1277 # one but owner may write to it. This function is of limited use
1278 # when called on a path instead of upon a handle, because there are
1279 # no guarantees that filename (by dirent) whose file (by ino) is
1280 # eventually accessed is the same as the one tested.
1281 # Assumes that the file's existence is not in doubt.
1284 stat($path) || return; # mysteriously vaporized
1285 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1287 return 0 if $uid != 0 && $uid != $<;
1288 return 0 if $mode & 022;
1290 } ## end sub is_safe_file
1292 # If the rcfile (whichever one we decided was the right one to read)
1293 # exists, we safely do it.
1295 safe_do("./$rcfile");
1298 # If there isn't one here, try the user's home directory.
1299 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1300 safe_do("$ENV{HOME}/$rcfile");
1303 # Else try the login directory.
1304 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1305 safe_do("$ENV{LOGDIR}/$rcfile");
1308 # If the PERLDB_OPTS variable has options in it, parse those out next.
1309 if ( defined $ENV{PERLDB_OPTS} ) {
1310 parse_options( $ENV{PERLDB_OPTS} );
1315 The last thing we do during initialization is determine which subroutine is
1316 to be used to obtain a new terminal when a new debugger is started. Right now,
1317 the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
1322 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1323 # Works if you're running an xterm or xterm-like window, or you're on
1324 # OS/2, or on Mac OS X. This may need some expansion.
1326 if (not defined &get_fork_TTY) # only if no routine exists
1328 if ( defined $remoteport ) {
1329 # Expect an inetd-like server
1330 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1332 elsif (defined $ENV{TERM} # If we know what kind
1333 # of terminal this is,
1334 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1335 and defined $ENV{DISPLAY} # and what display it's on,
1338 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1340 elsif ( $ENV{TMUX} ) {
1341 *get_fork_TTY = \&tmux_get_fork_TTY;
1343 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1344 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1346 elsif ( $^O eq 'darwin' # If this is Mac OS X
1347 and defined $ENV{TERM_PROGRAM} # and we're running inside
1348 and $ENV{TERM_PROGRAM}
1349 eq 'Apple_Terminal' # Terminal.app
1352 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1354 } ## end if (not defined &get_fork_TTY...
1356 # untaint $^O, which may have been tainted by the last statement.
1357 # see bug [perl #24674]
1361 # Here begin the unreadable code. It needs fixing.
1363 =head2 RESTART PROCESSING
1365 This section handles the restart command. When the C<R> command is invoked, it
1366 tries to capture all of the state it can into environment variables, and
1367 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1368 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1369 the R command stuffed into the environment variables.
1371 PERLDB_RESTART - flag only, contains no restart data itself.
1372 PERLDB_HIST - command history, if it's available
1373 PERLDB_ON_LOAD - breakpoints set by the rc file
1374 PERLDB_POSTPONE - subs that have been loaded/not executed,
1376 PERLDB_VISITED - files that had breakpoints
1377 PERLDB_FILE_... - breakpoints for a file
1378 PERLDB_OPT - active options
1379 PERLDB_INC - the original @INC
1380 PERLDB_PRETYPE - preprompt debugger actions
1381 PERLDB_PRE - preprompt Perl code
1382 PERLDB_POST - post-prompt Perl code
1383 PERLDB_TYPEAHEAD - typeahead captured by readline()
1385 We chug through all these variables and plug the values saved in them
1386 back into the appropriate spots in the debugger.
1390 use vars qw(%postponed_file @typeahead);
1392 our (@hist, @truehist);
1394 sub _restore_shared_globals_after_restart
1396 @hist = get_list('PERLDB_HIST');
1397 %break_on_load = get_list("PERLDB_ON_LOAD");
1398 %postponed = get_list("PERLDB_POSTPONE");
1402 share(%break_on_load);
1406 sub _restore_breakpoints_and_actions {
1408 my @had_breakpoints = get_list("PERLDB_VISITED");
1410 for my $file_idx ( 0 .. $#had_breakpoints ) {
1411 my $filename = $had_breakpoints[$file_idx];
1412 my %pf = get_list("PERLDB_FILE_$file_idx");
1413 $postponed_file{ $filename } = \%pf if %pf;
1414 my @lines = sort {$a <=> $b} keys(%pf);
1415 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1416 for my $line_idx (0 .. $#lines) {
1417 _set_breakpoint_enabled_status(
1420 ($enabled_statuses[$line_idx] ? 1 : ''),
1428 sub _restore_options_after_restart
1430 my %options_map = get_list("PERLDB_OPT");
1432 while ( my ( $opt, $val ) = each %options_map ) {
1433 $val =~ s/[\\\']/\\$1/g;
1434 parse_options("$opt'$val'");
1440 sub _restore_globals_after_restart
1442 # restore original @INC
1443 @INC = get_list("PERLDB_INC");
1446 # return pre/postprompt actions and typeahead buffer
1447 $pretype = [ get_list("PERLDB_PRETYPE") ];
1448 $pre = [ get_list("PERLDB_PRE") ];
1449 $post = [ get_list("PERLDB_POST") ];
1450 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1456 if ( exists $ENV{PERLDB_RESTART} ) {
1458 # We're restarting, so we don't need the flag that says to restart anymore.
1459 delete $ENV{PERLDB_RESTART};
1462 _restore_shared_globals_after_restart();
1464 _restore_breakpoints_and_actions();
1467 _restore_options_after_restart();
1469 _restore_globals_after_restart();
1470 } ## end if (exists $ENV{PERLDB_RESTART...
1472 =head2 SETTING UP THE TERMINAL
1474 Now, we'll decide how the debugger is going to interact with the user.
1475 If there's no TTY, we set the debugger to run non-stop; there's not going
1476 to be anyone there to enter commands.
1480 use vars qw($notty $console $tty $LINEINFO);
1481 use vars qw($lineinfo $doccmd);
1485 # Local autoflush to avoid rt#116769,
1486 # as calling IO::File methods causes an unresolvable loop
1487 # that results in debugger failure.
1489 my $o = select($_[0]);
1501 If there is a TTY, we have to determine who it belongs to before we can
1502 proceed. If this is a slave editor or graphical debugger (denoted by
1503 the first command-line switch being '-emacs'), we shift this off and
1504 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1510 # Is Perl being run from a slave editor or graphical debugger?
1511 # If so, don't use readline, and set $slave_editor = 1.
1512 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1517 #require Term::ReadLine;
1521 We then determine what the console should be on various systems:
1525 =item * Cygwin - We use C<stdin> instead of a separate device.
1529 if ( $^O eq 'cygwin' ) {
1531 # /dev/tty is binary. use stdin for textmode
1535 =item * Unix - use F</dev/tty>.
1539 elsif ( -e "/dev/tty" ) {
1540 $console = "/dev/tty";
1543 =item * Windows or MSDOS - use C<con>.
1547 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1551 =item * VMS - use C<sys$command>.
1557 # everything else is ...
1558 $console = "sys\$command";
1565 Several other systems don't use a specific console. We C<undef $console>
1566 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1567 with a slave editor).
1571 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1573 # /dev/tty is binary. use stdin for textmode
1577 if ( $^O eq 'NetWare' ) {
1579 # /dev/tty is binary. use stdin for textmode
1583 # In OS/2, we need to use STDIN to get textmode too, even though
1584 # it pretty much looks like Unix otherwise.
1585 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1592 If there is a TTY hanging around from a parent, we use that as the console.
1596 $console = $tty if defined $tty;
1598 =head2 SOCKET HANDLING
1600 The debugger is capable of opening a socket and carrying out a debugging
1601 session over the socket.
1603 If C<RemotePort> was defined in the options, the debugger assumes that it
1604 should try to start a debugging session on that port. It builds the socket
1605 and then tries to connect the input and output filehandles to it.
1609 # Handle socket stuff.
1611 if ( defined $remoteport ) {
1613 # If RemotePort was defined in the options, connect input and output
1615 $IN = $OUT = connect_remoteport();
1616 } ## end if (defined $remoteport)
1620 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1621 this is probably a situation where multiple debuggers are running (for example,
1622 a backticked command that starts up another debugger). We create a new IN and
1623 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1631 # Two debuggers running (probably a system or a backtick that invokes
1632 # the debugger itself under the running one). create a new IN and OUT
1633 # filehandle, and do the necessary mojo to create a new tty if we
1634 # know how, and we can.
1635 create_IN_OUT(4) if $CreateTTY & 4;
1638 # If we have a console, check to see if there are separate ins and
1639 # outs to open. (They are assumed identical if not.)
1641 my ( $i, $o ) = split /,/, $console;
1642 $o = $i unless defined $o;
1644 # read/write on in, or just read, or read on STDIN.
1646 || open( IN, "<$i" )
1647 || open( IN, "<&STDIN" );
1649 # read/write/create/clobber out, or write/create/clobber out,
1650 # or merge with STDERR, or merge with STDOUT.
1652 || open( OUT, ">$o" )
1653 || open( OUT, ">&STDERR" )
1654 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1656 } ## end if ($console)
1657 elsif ( not defined $console ) {
1659 # No console. Open STDIN.
1660 open( IN, "<&STDIN" );
1662 # merge with STDERR, or with STDOUT.
1663 open( OUT, ">&STDERR" )
1664 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1665 $console = 'STDIN/OUT';
1666 } ## end elsif (not defined $console)
1668 # Keep copies of the filehandles so that when the pager runs, it
1669 # can close standard input without clobbering ours.
1670 if ($console or (not defined($console))) {
1674 } ## end elsif (from if(defined $remoteport))
1676 # Unbuffer DB::OUT. We need to see responses right away.
1679 # Line info goes to debugger output unless pointed elsewhere.
1680 # Pointing elsewhere makes it possible for slave editors to
1681 # keep track of file and position. We have both a filehandle
1682 # and a I/O description to keep track of.
1683 $LINEINFO = $OUT unless defined $LINEINFO;
1684 $lineinfo = $console unless defined $lineinfo;
1685 # share($LINEINFO); # <- unable to share globs
1690 To finish initialization, we show the debugger greeting,
1691 and then call the C<afterinit()> subroutine if there is one.
1695 # Show the debugger greeting.
1696 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1697 unless ($runnonstop) {
1700 if ( $term_pid eq '-1' ) {
1701 print $OUT "\nDaughter DB session started...\n";
1704 print $OUT "\nLoading DB routines from $header\n";
1707 $slave_editor ? "enabled" : "available", ".\n"
1710 "\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
1711 } ## end else [ if ($term_pid eq '-1')
1712 } ## end unless ($runnonstop)
1713 } ## end else [ if ($notty)
1715 # XXX This looks like a bug to me.
1716 # Why copy to @ARGS and then futz with @args?
1719 # Make sure backslashes before single quotes are stripped out, and
1720 # keep args unless they are numeric (XXX why?)
1721 # s/\'/\\\'/g; # removed while not justified understandably
1722 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1725 # If there was an afterinit() sub defined, call it. It will get
1726 # executed in our scope, so it can fiddle with debugger globals.
1727 if ( defined &afterinit ) { # May be defined in $rcfile
1731 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1732 use vars qw($I_m_init);
1736 ############################################################ Subroutines
1742 This gigantic subroutine is the heart of the debugger. Called before every
1743 statement, its job is to determine if a breakpoint has been reached, and
1744 stop if so; read commands from the user, parse them, and execute
1745 them, and then send execution off to the next statement.
1747 Note that the order in which the commands are processed is very important;
1748 some commands earlier in the loop will actually alter the C<$cmd> variable
1749 to create other commands to be executed later. This is all highly I<optimized>
1750 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1751 see what's happening in any given command.
1755 # $cmd cannot be an our() variable unfortunately (possible perl bug?).
1785 sub _DB__determine_if_we_should_break
1787 # if we have something here, see if we should break.
1788 # $stop is lexical and local to this block - $action on the other hand
1793 && _is_breakpoint_enabled($filename, $line)
1794 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1797 # Stop if the stop criterion says to just stop.
1798 if ( $stop eq '1' ) {
1802 # It's a conditional stop; eval it in the user's context and
1803 # see if we should stop. If so, remove the one-time sigil.
1805 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1806 # The &-call is here to ascertain the mutability of @_.
1808 # If the breakpoint is temporary, then delete its enabled status.
1809 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1810 _cancel_breakpoint_temp_enabled_status($filename, $line);
1813 } ## end if ($dbline{$line} && ...
1816 sub _DB__is_finished {
1817 if ($finished and $level <= 1) {
1826 sub _DB__read_next_cmd
1830 # We have a terminal, or can get one ...
1835 # ... and it belongs to this PID or we get one for this PID ...
1836 if ($term_pid != $$) {
1840 # ... and we got a line of command input ...
1841 $cmd = DB::readline(
1842 "$pidprompt $tid DB"
1845 . ( '>' x $level ) . " "
1848 return defined($cmd);
1851 sub _DB__trim_command_and_return_first_component {
1854 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1855 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1857 my ($verb, $args) = $cmd =~ m{\A(\S*)\s*(.*)}s;
1859 $obj->cmd_verb($verb);
1860 $obj->cmd_args($args);
1865 sub _DB__handle_f_command {
1868 if ($file = $obj->cmd_args) {
1869 # help for no arguments (old-style was return from sub).
1872 "The old f command is now the r command.\n"; # hint
1873 print $OUT "The new f command switches filenames.\n";
1875 } ## end if (!$file)
1877 # if not in magic file list, try a close match.
1878 if ( !defined $main::{ '_<' . $file } ) {
1879 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1881 $try = substr( $try, 2 );
1882 print $OUT "Choosing $try matching '$file':\n";
1885 } ## end if (($try) = grep(m#^_<.*$file#...
1886 } ## end if (!defined $main::{ ...
1888 # If not successfully switched now, we failed.
1889 if ( !defined $main::{ '_<' . $file } ) {
1890 print $OUT "No file matching '$file' is loaded.\n";
1894 # We switched, so switch the debugger internals around.
1895 elsif ( $file ne $filename ) {
1896 *dbline = $main::{ '_<' . $file };
1901 } ## end elsif ($file ne $filename)
1903 # We didn't switch; say we didn't.
1905 print $OUT "Already in $file.\n";
1913 sub _DB__handle_dot_command {
1917 if ($obj->_is_full('.')) {
1918 $incr = -1; # stay at current line
1920 # Reset everything to the old location.
1922 $filename = $filename_ini;
1923 *dbline = $main::{ '_<' . $filename };
1927 print_lineinfo($obj->position());
1934 sub _DB__handle_y_command {
1937 if (my ($match_level, $match_vars)
1938 = $obj->cmd_args =~ /\A(?:(\d*)\s*(.*))?\z/) {
1940 # See if we've got the necessary support.
1941 if (!eval { require PadWalker; PadWalker->VERSION(0.08) }) {
1945 ? "PadWalker module not found - please install\n"
1951 # Load up dumpvar if we don't have it. If we can, that is.
1952 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1953 defined &main::dumpvar
1954 or print $OUT "dumpvar.pl not available.\n"
1957 # Got all the modules we need. Find them and print them.
1958 my @vars = split( ' ', $match_vars || '' );
1961 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 2 ) };
1963 # Oops. Can't find it.
1970 # Show the desired vars with dumplex().
1971 my $savout = select($OUT);
1973 # Have dumplex dump the lexicals.
1974 foreach my $key (sort keys %$h) {
1975 dumpvar::dumplex( $key, $h->{$key},
1976 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
1984 sub _DB__handle_c_command {
1987 my $i = $obj->cmd_args;
1989 if ($i =~ m#\A[\w:]*\z#) {
1991 # Hey, show's over. The debugged program finished
1992 # executing already.
1993 next CMD if _DB__is_finished();
1995 # Capture the place to put a one-time break.
1998 # Probably not needed, since we finish an interactive
1999 # sub-session anyway...
2000 # local $filename = $filename;
2001 # local *dbline = *dbline; # XXX Would this work?!
2003 # The above question wonders if localizing the alias
2004 # to the magic array works or not. Since it's commented
2005 # out, we'll just leave that to speculation for now.
2007 # If the "subname" isn't all digits, we'll assume it
2008 # is a subroutine name, and try to find it.
2009 if ( $subname =~ /\D/ ) { # subroutine name
2010 # Qualify it to the current package unless it's
2011 # already qualified.
2012 $subname = $package . "::" . $subname
2013 unless $subname =~ /::/;
2015 # find_sub will return "file:line_number" corresponding
2016 # to where the subroutine is defined; we call find_sub,
2017 # break up the return value, and assign it in one
2019 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2021 # Force the line number to be numeric.
2024 # If we got a line number, we found the sub.
2027 # Switch all the debugger's internals around so
2028 # we're actually working with that file.
2030 *dbline = $main::{ '_<' . $filename };
2032 # Mark that there's a breakpoint in this file.
2033 $had_breakpoints{$filename} |= 1;
2035 # Scan forward to the first executable line
2036 # after the 'sub whatever' line.
2039 while ($dbline[$_line_num] == 0 && $_line_num< $max)
2046 # We didn't find a sub by that name.
2048 print $OUT "Subroutine $subname not found.\n";
2051 } ## end if ($subname =~ /\D/)
2053 # At this point, either the subname was all digits (an
2054 # absolute line-break request) or we've scanned through
2055 # the code following the definition of the sub, looking
2056 # for an executable, which we may or may not have found.
2058 # If $i (which we set $subname from) is non-zero, we
2059 # got a request to break at some line somewhere. On
2060 # one hand, if there wasn't any real subroutine name
2061 # involved, this will be a request to break in the current
2062 # file at the specified line, so we have to check to make
2063 # sure that the line specified really is breakable.
2065 # On the other hand, if there was a subname supplied, the
2066 # preceding block has moved us to the proper file and
2067 # location within that file, and then scanned forward
2068 # looking for the next executable line. We have to make
2069 # sure that one was found.
2071 # On the gripping hand, we can't do anything unless the
2072 # current value of $i points to a valid breakable line.
2077 if ( $dbline[$i] == 0 ) {
2078 print $OUT "Line $i not breakable.\n";
2082 # Yes. Set up the one-time-break sigil.
2083 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2084 _enable_breakpoint_temp_enabled_status($filename, $i);
2087 # Turn off stack tracing from here up.
2088 for my $j (0 .. $stack_depth) {
2097 sub _DB__handle_forward_slash_command {
2100 # The pattern as a string.
2101 use vars qw($inpat);
2103 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2105 # Remove the final slash.
2106 $inpat =~ s:([^\\])/$:$1:;
2108 # If the pattern isn't null ...
2109 if ( $inpat ne "" ) {
2111 # Turn off warn and die processing for a bit.
2112 local $SIG{__DIE__};
2113 local $SIG{__WARN__};
2115 # Create the pattern.
2116 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2119 # Oops. Bad pattern. No biscuit.
2120 # Print the eval error and go back for more
2126 } ## end if ($inpat ne "")
2128 # Set up to stop on wrap-around.
2131 # Don't move off the current line.
2134 my $pat = $obj->pat;
2136 # Done in eval so nothing breaks if the pattern
2137 # does something weird.
2142 # Move ahead one line.
2145 # Wrap if we pass the last line.
2146 if ($start > $max) {
2150 # Stop if we have gotten back to this line again,
2151 last if ($start == $end);
2153 # A hit! (Note, though, that we are doing
2154 # case-insensitive matching. Maybe a qr//
2155 # expression would be better, so the user could
2156 # do case-sensitive matching if desired.
2157 if ($dbline[$start] =~ m/$pat/i) {
2158 if ($slave_editor) {
2159 # Handle proper escaping in the slave.
2160 print {$OUT} "\032\032$filename:$start:0\n";
2163 # Just print the line normally.
2164 print {$OUT} "$start:\t",$dbline[$start],"\n";
2166 # And quit since we found something.
2176 # If we wrapped, there never was a match.
2177 if ( $start == $end ) {
2178 print {$OUT} "/$pat/: not found\n";
2186 sub _DB__handle_question_mark_command {
2189 # ? - backward pattern search.
2190 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2192 # Get the pattern, remove trailing question mark.
2193 $inpat =~ s:([^\\])\?$:$1:;
2195 # If we've got one ...
2196 if ( $inpat ne "" ) {
2198 # Turn off die & warn handlers.
2199 local $SIG{__DIE__};
2200 local $SIG{__WARN__};
2201 eval '$inpat =~ m' . "\a$inpat\a";
2205 # Ouch. Not good. Print the error.
2210 } ## end if ($inpat ne "")
2212 # Where we are now is where to stop after wraparound.
2215 # Don't move away from this line.
2218 my $pat = $obj->pat;
2219 # Search inside the eval to prevent pattern badness
2227 # Wrap if we pass the first line.
2229 $start = $max if ($start <= 0);
2231 # Quit if we get back where we started,
2232 last if ($start == $end);
2235 if ($dbline[$start] =~ m/$pat/i) {
2236 if ($slave_editor) {
2237 # Yep, follow slave editor requirements.
2238 print $OUT "\032\032$filename:$start:0\n";
2241 # Yep, just print normally.
2242 print $OUT "$start:\t",$dbline[$start],"\n";
2251 # Say we failed if the loop never found anything,
2252 if ( $start == $end ) {
2253 print {$OUT} "?$pat?: not found\n";
2261 sub _DB__handle_restart_and_rerun_commands {
2264 my $cmd_cmd = $obj->cmd_verb;
2265 my $cmd_params = $obj->cmd_args;
2266 # R - restart execution.
2267 # rerun - controlled restart execution.
2268 if ($cmd_cmd eq 'rerun' or $cmd_params eq '') {
2270 # Change directory to the initial current working directory on
2271 # the script startup, so if the debugged program changed the
2272 # directory, then we will still be able to find the path to the
2273 # the program. (perl 5 RT #121509 ).
2274 chdir ($_initial_cwd);
2276 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
2278 # Close all non-system fds for a clean restart. A more
2279 # correct method would be to close all fds that were not
2280 # open when the process started, but this seems to be
2281 # hard. See "debugger 'R'estart and open database
2282 # connections" on p5p.
2284 my $max_fd = 1024; # default if POSIX can't be loaded
2285 if (eval { require POSIX }) {
2286 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
2289 if (defined $max_fd) {
2290 foreach ($^F+1 .. $max_fd-1) {
2291 next unless open FD_TO_CLOSE, "<&=$_";
2296 # And run Perl again. We use exec() to keep the
2297 # PID stable (and that way $ini_pids is still valid).
2298 exec(@args) or print {$OUT} "exec failed: $!\n";
2306 sub _DB__handle_run_command_in_pager_command {
2309 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
2310 if ( $pager =~ /^\|/ ) {
2312 # Default pager is into a pipe. Redirect I/O.
2313 open( SAVEOUT, ">&STDOUT" )
2314 || _db_warn("Can't save STDOUT");
2315 open( STDOUT, ">&OUT" )
2316 || _db_warn("Can't redirect STDOUT");
2317 } ## end if ($pager =~ /^\|/)
2320 # Not into a pipe. STDOUT is safe.
2321 open( SAVEOUT, ">&OUT" ) || _db_warn("Can't save DB::OUT");
2324 # Fix up environment to record we have less if so.
2327 unless ( $obj->piped(scalar ( open( OUT, $pager ) ) ) ) {
2329 # Couldn't open pipe to pager.
2330 _db_warn("Can't pipe output to '$pager'");
2331 if ( $pager =~ /^\|/ ) {
2333 # Redirect I/O back again.
2334 open( OUT, ">&STDOUT" ) # XXX: lost message
2335 || _db_warn("Can't restore DB::OUT");
2336 open( STDOUT, ">&SAVEOUT" )
2337 || _db_warn("Can't restore STDOUT");
2339 } ## end if ($pager =~ /^\|/)
2342 # Redirect I/O. STDOUT already safe.
2343 open( OUT, ">&STDOUT" ) # XXX: lost message
2344 || _db_warn("Can't restore DB::OUT");
2347 } ## end unless ($piped = open(OUT,...
2349 # Set up broken-pipe handler if necessary.
2350 $SIG{PIPE} = \&DB::catch
2352 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
2355 # Save current filehandle, and put it back.
2356 $obj->selected(scalar( select(OUT) ));
2357 # Don't put it back if pager was a pipe.
2358 if ($cmd !~ /\A\|\|/)
2360 select($obj->selected());
2364 # Trim off the pipe symbols and run the command now.
2365 $cmd =~ s#\A\|+\s*##;
2372 sub _DB__handle_m_command {
2375 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2380 # m expr - set up DB::eval to do the work
2381 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2382 $onetimeDump = 'methods'; # method output gets used there
2388 sub _DB__at_end_of_every_command {
2391 # At the end of every command:
2394 # Unhook the pipe mechanism now.
2395 if ( $pager =~ /^\|/ ) {
2397 # No error from the child.
2400 # we cannot warn here: the handle is missing --tchrist
2401 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
2403 # most of the $? crud was coping with broken cshisms
2404 # $? is explicitly set to 0, so this never runs.
2406 print SAVEOUT "Pager '$pager' failed: ";
2408 print SAVEOUT "shell returned -1\n";
2411 print SAVEOUT ( $? & 127 )
2412 ? " (SIG#" . ( $? & 127 ) . ")"
2413 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
2416 print SAVEOUT "status ", ( $? >> 8 ), "\n";
2420 # Reopen filehandle for our output (if we can) and
2421 # restore STDOUT (if we can).
2422 open( OUT, ">&STDOUT" ) || _db_warn("Can't restore DB::OUT");
2423 open( STDOUT, ">&SAVEOUT" )
2424 || _db_warn("Can't restore STDOUT");
2426 # Turn off pipe exception handler if necessary.
2427 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
2429 # Will stop ignoring SIGPIPE if done like nohup(1)
2430 # does SIGINT but Perl doesn't give us a choice.
2431 } ## end if ($pager =~ /^\|/)
2434 # Non-piped "pager". Just restore STDOUT.
2435 open( OUT, ">&SAVEOUT" ) || _db_warn("Can't restore DB::OUT");
2438 # Let Readline know about the new filehandles.
2439 reset_IN_OUT( \*IN, \*OUT );
2441 # Close filehandle pager was using, restore the normal one
2445 if ($obj->selected() ne "") {
2446 select($obj->selected);
2452 } ## end if ($piped)
2457 sub _DB__handle_watch_expressions
2461 if ( $DB::trace & 2 ) {
2462 for my $n (0 .. $#DB::to_watch) {
2463 $DB::evalarg = $DB::to_watch[$n];
2464 local $DB::onetimeDump; # Tell DB::eval() to not output results
2466 # Fix context DB::eval() wants to return an array, but
2467 # we need a scalar here.
2468 my ($val) = join( "', '", DB::eval(@_) );
2469 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
2472 if ( $val ne $DB::old_watch[$n] ) {
2474 # Yep! Show the difference, and fake an interrupt.
2476 print {$DB::OUT} <<EOP;
2477 Watchpoint $n:\t$DB::to_watch[$n] changed:
2478 old value:\t$DB::old_watch[$n]
2481 $DB::old_watch[$n] = $val;
2482 } ## end if ($val ne $old_watch...
2483 } ## end for my $n (0 ..
2484 } ## end if ($trace & 2)
2491 # 'v' is the value (i.e: method name or subroutine ref).
2492 # 's' is subroutine.
2495 '-' => { t => 'm', v => '_handle_dash_command', },
2496 '.' => { t => 's', v => \&_DB__handle_dot_command, },
2497 '=' => { t => 'm', v => '_handle_equal_sign_command', },
2498 'H' => { t => 'm', v => '_handle_H_command', },
2499 'S' => { t => 'm', v => '_handle_S_command', },
2500 'T' => { t => 'm', v => '_handle_T_command', },
2501 'W' => { t => 'm', v => '_handle_W_command', },
2502 'c' => { t => 's', v => \&_DB__handle_c_command, },
2503 'f' => { t => 's', v => \&_DB__handle_f_command, },
2504 'm' => { t => 's', v => \&_DB__handle_m_command, },
2505 'n' => { t => 'm', v => '_handle_n_command', },
2506 'p' => { t => 'm', v => '_handle_p_command', },
2507 'q' => { t => 'm', v => '_handle_q_command', },
2508 'r' => { t => 'm', v => '_handle_r_command', },
2509 's' => { t => 'm', v => '_handle_s_command', },
2510 'save' => { t => 'm', v => '_handle_save_command', },
2511 'source' => { t => 'm', v => '_handle_source_command', },
2512 't' => { t => 'm', v => '_handle_t_command', },
2513 'w' => { t => 'm', v => '_handle_w_command', },
2514 'x' => { t => 'm', v => '_handle_x_command', },
2515 'y' => { t => 's', v => \&_DB__handle_y_command, },
2516 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, }
2518 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, }
2519 qw(enable disable)),
2521 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, },
2523 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, }
2524 qw(a A b B e E h i l L M o O v w W)),
2529 # lock the debugger and get the thread id for the prompt
2533 my ($prefix, $after, $infix);
2539 if ($ENV{PERL5DB_THREADED}) {
2540 $tid = eval { "[".threads->tid."]" };
2546 my $obj = DB::Obj->new(
2548 position => \$position,
2551 explicit_stop => \$explicit_stop,
2553 cmd_args => \$cmd_args,
2554 cmd_verb => \$cmd_verb,
2557 selected => \$selected,
2561 $obj->_DB_on_init__initialize_globals(@_);
2563 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2564 # The code being debugged may have altered them.
2567 # Since DB::DB gets called after every line, we can use caller() to
2568 # figure out where we last were executing. Sneaky, eh? This works because
2569 # caller is returning all the extra information when called from the
2571 local ( $package, $filename, $line ) = caller;
2572 $filename_ini = $filename;
2574 # set up the context for DB::eval, so it can properly execute
2575 # code on behalf of the user. We add the package in so that the
2576 # code is eval'ed in the proper package (not in the debugger!).
2577 local $usercontext = _calc_usercontext($package);
2579 # Create an alias to the active file magical array to simplify
2581 local (*dbline) = $main::{ '_<' . $filename };
2583 # Last line in the program.
2586 # The &-call is here to ascertain the mutability of @_.
2587 &_DB__determine_if_we_should_break;
2589 # Preserve the current stop-or-not, and see if any of the W
2590 # (watch expressions) has changed.
2591 my $was_signal = $signal;
2593 # If we have any watch expressions ...
2594 _DB__handle_watch_expressions($obj);
2596 =head2 C<watchfunction()>
2598 C<watchfunction()> is a function that can be defined by the user; it is a
2599 function which will be run on each entry to C<DB::DB>; it gets the
2600 current package, filename, and line as its parameters.
2602 The watchfunction can do anything it likes; it is executing in the
2603 debugger's context, so it has access to all of the debugger's internal
2604 data structures and functions.
2606 C<watchfunction()> can control the debugger's actions. Any of the following
2607 will cause the debugger to return control to the user's program after
2608 C<watchfunction()> executes:
2614 Returning a false value from the C<watchfunction()> itself.
2618 Altering C<$single> to a false value.
2622 Altering C<$signal> to a false value.
2626 Turning off the C<4> bit in C<$trace> (this also disables the
2627 check for C<watchfunction()>. This can be done with
2635 # If there's a user-defined DB::watchfunction, call it with the
2636 # current package, filename, and line. The function executes in
2638 if ( $trace & 4 ) { # User-installed watch
2640 if watchfunction( $package, $filename, $line )
2643 and not( $trace & ~4 );
2644 } ## end if ($trace & 4)
2646 # Pick up any alteration to $signal in the watchfunction, and
2647 # turn off the signal now.
2648 $was_signal = $signal;
2651 =head2 GETTING READY TO EXECUTE COMMANDS
2653 The debugger decides to take control if single-step mode is on, the
2654 C<t> command was entered, or the user generated a signal. If the program
2655 has fallen off the end, we set things up so that entering further commands
2656 won't cause trouble, and we say that the program is over.
2660 # Make sure that we always print if asked for explicitly regardless
2661 # of $trace_to_depth .
2662 $explicit_stop = ($single || $was_signal);
2664 # Check to see if we should grab control ($single true,
2665 # trace set appropriately, or we got a signal).
2666 if ( $explicit_stop || ( $trace & 1 ) ) {
2667 $obj->_DB__grab_control(@_);
2668 } ## end if ($single || ($trace...
2672 If there's an action to be executed for the line we stopped at, execute it.
2673 If there are any preprompt actions, execute those as well.
2677 # If there's an action, do it now.
2680 # The &-call is here to ascertain the mutability of @_.
2684 # Are we nested another level (e.g., did we evaluate a function
2685 # that had a breakpoint in it at the debugger prompt)?
2686 if ( $single || $was_signal ) {
2688 # Yes, go down a level.
2689 local $level = $level + 1;
2691 # Do any pre-prompt actions.
2692 foreach $evalarg (@$pre) {
2693 # The &-call is here to ascertain the mutability of @_.
2697 # Complain about too much recursion if we passed the limit.
2699 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2702 # The line we're currently on. Set $incr to -1 to stay here
2703 # until we get a command that tells us to advance.
2705 $incr = -1; # for backward motion.
2707 # Tack preprompt debugger actions ahead of any actual input.
2708 @typeahead = ( @$pretype, @typeahead );
2710 =head2 WHERE ARE WE?
2712 XXX Relocate this section?
2714 The debugger normally shows the line corresponding to the current line of
2715 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2716 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2718 C<$incr> controls by how many lines the I<current> line should move forward
2719 after a command is executed. If set to -1, this indicates that the I<current>
2720 line shouldn't change.
2722 C<$start> is the I<current> line. It is used for things like knowing where to
2723 move forwards or backwards from when doing an C<L> or C<-> command.
2725 C<$max> tells the debugger where the last line of the current file is. It's
2726 used to terminate loops most often.
2728 =head2 THE COMMAND LOOP
2730 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2737 The outer part of the loop, starting at the C<CMD> label. This loop
2738 reads a command and then executes it.
2742 The inner part of the loop, starting at the C<PIPE> label. This part
2743 is wholly contained inside the C<CMD> block and only executes a command.
2744 Used to handle commands running inside a pager.
2748 So why have two labels to restart the loop? Because sometimes, it's easier to
2749 have a command I<generate> another command and then re-execute the loop to do
2750 the new command. This is faster, but perhaps a bit more convoluted.
2754 # The big command dispatch loop. It keeps running until the
2755 # user yields up control again.
2757 # If we have a terminal for input, and we get something back
2758 # from readline(), keep on processing.
2761 while (_DB__read_next_cmd($tid))
2765 # ... try to execute the input as debugger commands.
2767 # Don't stop running.
2770 # No signal is active.
2773 # Handle continued commands (ending with \):
2774 if ($cmd =~ s/\\\z/\n/) {
2775 $cmd .= DB::readline(" cont: ");
2779 =head4 The null command
2781 A newline entered by itself means I<re-execute the last command>. We grab the
2782 command out of C<$laststep> (where it was recorded previously), and copy it
2783 back into C<$cmd> to be executed below. If there wasn't any previous command,
2784 we'll do nothing below (no command will match). If there was, we also save it
2785 in the command history and fall through to allow the command parsing to pick
2790 # Empty input means repeat the last command.
2794 chomp($cmd); # get rid of the annoying extra newline
2795 if (length($cmd) >= 2) {
2796 push( @hist, $cmd );
2798 push( @truehist, $cmd );
2802 # This is a restart point for commands that didn't arrive
2803 # via direct user input. It allows us to 'redo PIPE' to
2804 # re-execute command processing without reading a new command.
2806 _DB__trim_command_and_return_first_component($obj);
2808 =head3 COMMAND ALIASES
2810 The debugger can create aliases for commands (these are stored in the
2811 C<%alias> hash). Before a command is executed, the command loop looks it up
2812 in the alias hash and substitutes the contents of the alias for the command,
2813 completely replacing it.
2817 # See if there's an alias for the command, and set it up if so.
2818 if ( $alias{$cmd_verb} ) {
2820 # Squelch signal handling; we want to keep control here
2821 # if something goes loco during the alias eval.
2822 local $SIG{__DIE__};
2823 local $SIG{__WARN__};
2825 # This is a command, so we eval it in the DEBUGGER's
2826 # scope! Otherwise, we can't see the special debugger
2827 # variables, or get to the debugger's subs. (Well, we
2828 # _could_, but why make it even more complicated?)
2829 eval "\$cmd =~ $alias{$cmd_verb}";
2832 print $OUT "Couldn't evaluate '$cmd_verb' alias: $@";
2835 _DB__trim_command_and_return_first_component($obj);
2836 } ## end if ($alias{$cmd_verb})
2838 =head3 MAIN-LINE COMMANDS
2840 All of these commands work up to and after the program being debugged has
2845 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2846 try to execute further, cleaning any restart-related stuff out of the
2847 environment, and executing with the last value of C<$?>.
2851 # All of these commands were remapped in perl 5.8.0;
2852 # we send them off to the secondary dispatcher (see below).
2853 $obj->_handle_special_char_cmd_wrapper_commands;
2854 _DB__trim_command_and_return_first_component($obj);
2856 if (my $cmd_rec = $cmd_lookup{$cmd_verb}) {
2857 my $type = $cmd_rec->{t};
2858 my $val = $cmd_rec->{v};
2862 elsif ($type eq 's') {
2867 =head4 C<t> - trace [n]
2869 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2870 If level is specified, set C<$trace_to_depth>.
2872 =head4 C<S> - list subroutines matching/not matching a pattern
2874 Walks through C<%sub>, checking to see whether or not to print the name.
2876 =head4 C<X> - list variables in current package
2878 Since the C<V> command actually processes this, just change this to the
2879 appropriate C<V> command and fall through.
2881 =head4 C<V> - list variables
2883 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2885 =head4 C<x> - evaluate and print an expression
2887 Hands the expression off to C<DB::eval>, setting it up to print the value
2888 via C<dumpvar.pl> instead of just printing it directly.
2890 =head4 C<m> - print methods
2892 Just uses C<DB::methods> to determine what methods are available.
2894 =head4 C<f> - switch files
2896 Switch to a different filename.
2898 =head4 C<.> - return to last-executed line.
2900 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2901 and then we look up the line in the magical C<%dbline> hash.
2903 =head4 C<-> - back one window
2905 We change C<$start> to be one window back; if we go back past the first line,
2906 we set it to be the first line. We ser C<$incr> to put us back at the
2907 currently-executing line, and then put a C<l $start +> (list one window from
2908 C<$start>) in C<$cmd> to be executed later.
2910 =head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
2912 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2913 problems, most notably that the default case of several commands destroying
2914 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2915 retain the old commands for those who were used to using them or who preferred
2916 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2917 deal with them instead of processing them in-line.
2919 =head4 C<y> - List lexicals in higher scope
2921 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2922 above the current one and then displays then using C<dumpvar.pl>.
2924 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2926 All of the commands below this point don't work after the program being
2927 debugged has ended. All of them check to see if the program has ended; this
2928 allows the commands to be relocated without worrying about a 'line of
2929 demarcation' above which commands can be entered anytime, and below which
2932 =head4 C<n> - single step, but don't trace down into subs
2934 Done by setting C<$single> to 2, which forces subs to execute straight through
2935 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2936 so a null command knows what to re-execute.
2938 =head4 C<s> - single-step, entering subs
2940 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2941 subs. Also saves C<s> as C<$lastcmd>.
2943 =head4 C<c> - run continuously, setting an optional breakpoint
2945 Most of the code for this command is taken up with locating the optional
2946 breakpoint, which is either a subroutine name or a line number. We set
2947 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2948 in this and all call levels above this one.
2950 =head4 C<r> - return from a subroutine
2952 For C<r> to work properly, the debugger has to stop execution again
2953 immediately after the return is executed. This is done by forcing
2954 single-stepping to be on in the call level above the current one. If
2955 we are printing return values when a C<r> is executed, set C<$doret>
2956 appropriately, and force us out of the command loop.
2958 =head4 C<T> - stack trace
2960 Just calls C<DB::print_trace>.
2962 =head4 C<w> - List window around current line.
2964 Just calls C<DB::cmd_w>.
2966 =head4 C<W> - watch-expression processing.
2968 Just calls C<DB::cmd_W>.
2970 =head4 C</> - search forward for a string in the source
2972 We take the argument and treat it as a pattern. If it turns out to be a
2973 bad one, we return the error we got from trying to C<eval> it and exit.
2974 If not, we create some code to do the search and C<eval> it so it can't
2979 _DB__handle_forward_slash_command($obj);
2981 =head4 C<?> - search backward for a string in the source
2983 Same as for C</>, except the loop runs backwards.
2987 _DB__handle_question_mark_command($obj);
2989 =head4 C<$rc> - Recall command
2991 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2992 that the terminal supports history). It finds the command required, puts it
2993 into C<$cmd>, and redoes the loop to execute it.
2997 # $rc - recall command.
2998 $obj->_handle_rc_recall_command;
3000 =head4 C<$sh$sh> - C<system()> command
3002 Calls the C<_db_system()> to handle the command. This keeps the C<STDIN> and
3003 C<STDOUT> from getting messed up.
3007 $obj->_handle_sh_command;
3009 =head4 C<$rc I<pattern> $rc> - Search command history
3011 Another command to manipulate C<@hist>: this one searches it with a pattern.
3012 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
3016 $obj->_handle_rc_search_history_command;
3018 =head4 C<$sh> - Invoke a shell
3020 Uses C<_db_system()> to invoke a shell.
3024 =head4 C<$sh I<command>> - Force execution of a command in a shell
3026 Like the above, but the command is passed to the shell. Again, we use
3027 C<_db_system()> to avoid problems with C<STDIN> and C<STDOUT>.
3029 =head4 C<H> - display commands in history
3031 Prints the contents of C<@hist> (if any).
3033 =head4 C<man, doc, perldoc> - look up documentation
3035 Just calls C<runman()> to print the appropriate document.
3039 $obj->_handle_doc_command;
3043 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3044 the bottom of the loop.
3046 =head4 C<=> - define command alias
3048 Manipulates C<%alias> to add or list command aliases.
3050 =head4 C<source> - read commands from a file.
3052 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3055 =head4 C<enable> C<disable> - enable or disable breakpoints
3057 This enables or disables breakpoints.
3059 =head4 C<save> - send current history to a file
3061 Takes the complete history, (not the shrunken version you see with C<H>),
3062 and saves it to the given filename, so it can be replayed using C<source>.
3064 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3066 =head4 C<R> - restart
3068 Restart the debugger session.
3070 =head4 C<rerun> - rerun the current session
3072 Return to any given position in the B<true>-history list
3074 =head4 C<|, ||> - pipe output through the pager.
3076 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3077 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3078 pipe to the pager (restoring the output filehandles if this fails). If this
3079 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3080 set C<$signal>, sending us back into the debugger.
3082 We then trim off the pipe symbols and C<redo> the command loop at the
3083 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3088 # || - run command in the pager, with output to DB::OUT.
3089 _DB__handle_run_command_in_pager_command($obj);
3091 =head3 END OF COMMAND PARSING
3093 Anything left in C<$cmd> at this point is a Perl expression that we want to
3094 evaluate. We'll always evaluate in the user's context, and fully qualify
3095 any variables we might want to address in the C<DB> package.
3101 # trace an expression
3102 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3104 # Make sure the flag that says "the debugger's running" is
3105 # still on, to make sure we get control again.
3106 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3108 # Run *our* eval that executes in the caller's context.
3109 # The &-call is here to ascertain the mutability of @_.
3112 # Turn off the one-time-dump stuff now.
3114 $onetimeDump = undef;
3115 $onetimedumpDepth = undef;
3117 elsif ( $term_pid == $$ ) {
3118 eval { # May run under miniperl, when not available...
3123 # XXX If this is the master pid, print a newline.
3126 } ## end while (($term || &setterm...
3128 =head3 POST-COMMAND PROCESSING
3130 After each command, we check to see if the command output was piped anywhere.
3131 If so, we go through the necessary code to unhook the pipe and go back to
3132 our standard filehandles for input and output.
3137 _DB__at_end_of_every_command($obj);
3140 =head3 COMMAND LOOP TERMINATION
3142 When commands have finished executing, we come here. If the user closed the
3143 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3144 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3145 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3146 The interpreter will then execute the next line and then return control to us
3151 # No more commands? Quit.
3152 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
3154 # Evaluate post-prompt commands.
3155 foreach $evalarg (@$post) {
3156 # The &-call is here to ascertain the mutability of @_.
3159 } # if ($single || $signal)
3161 # Put the user's globals back where you found them.
3162 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3166 # Because DB::Obj is used above,
3168 # my $obj = DB::Obj->new(
3170 # The following package declaration must come before that,
3171 # or else runtime errors will occur with
3173 # PERLDB_OPTS="autotrace nonstop"
3183 my $self = bless {}, $class;
3191 my ($self, $args) = @_;
3193 %{$self} = (%$self, %$args);
3200 foreach my $slot_name (qw(
3201 after explicit_stop infix pat piped position prefix selected cmd_verb
3204 my $slot = $slot_name;
3209 ${ $self->{$slot} } = shift;
3212 return ${ $self->{$slot} };
3215 *{"append_to_$slot"} = sub {
3219 return $self->$slot($self->$slot . $s);
3224 sub _DB_on_init__initialize_globals
3228 # Check for whether we should be running continuously or not.
3229 # _After_ the perl program is compiled, $single is set to 1:
3230 if ( $single and not $second_time++ ) {
3232 # Options say run non-stop. Run until we get an interrupt.
3233 if ($runnonstop) { # Disable until signal
3234 # If there's any call stack in place, turn off single
3235 # stepping into subs throughout the stack.
3236 for my $i (0 .. $stack_depth) {
3240 # And we are now no longer in single-step mode.
3243 # If we simply returned at this point, we wouldn't get
3244 # the trace info. Fall on through.
3246 } ## end if ($runnonstop)
3248 elsif ($ImmediateStop) {
3250 # We are supposed to stop here; XXX probably a break.
3251 $ImmediateStop = 0; # We've processed it; turn it off
3252 $signal = 1; # Simulate an interrupt to force
3253 # us into the command loop
3255 } ## end if ($single and not $second_time...
3257 # If we're in single-step mode, or an interrupt (real or fake)
3258 # has occurred, turn off non-stop mode.
3259 $runnonstop = 0 if $single or $signal;
3264 sub _my_print_lineinfo
3266 my ($self, $i, $incr_pos) = @_;
3269 # Print it indented if tracing is on.
3270 DB::print_lineinfo( ' ' x $stack_depth,
3271 "$i:\t$DB::dbline[$i]" . $self->after );
3274 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3279 return $DB::dbline[$line];
3283 my ($self, $letter) = @_;
3285 return ($DB::cmd eq $letter);
3288 sub _DB__grab_control
3292 # Yes, grab control.
3293 if ($slave_editor) {
3295 # Tell the editor to update its position.
3296 $self->position("\032\032${DB::filename}:$line:0\n");
3297 DB::print_lineinfo($self->position());
3302 Special check: if we're in package C<DB::fake>, we've gone through the
3303 C<END> block at least once. We set up everything so that we can continue
3304 to enter commands and have a valid context to be in.
3308 elsif ( $DB::package eq 'DB::fake' ) {
3310 # Fallen off the end already.
3315 DB::print_help(<<EOP);
3316 Debugged program terminated. Use B<q> to quit or B<R> to restart,
3317 use B<o> I<inhibit_exit> to avoid stopping after program termination,
3318 B<h q>, B<h R> or B<h o> to get additional info.
3321 # Set the DB::eval context appropriately.
3322 # At program termination disable any user actions.
3323 $DB::action = undef;
3325 $DB::package = 'main';
3326 $DB::usercontext = DB::_calc_usercontext($DB::package);
3327 } ## end elsif ($package eq 'DB::fake')
3331 If the program hasn't finished executing, we scan forward to the
3332 next executable line, print that out, build the prompt from the file and line
3333 number information, and print that.
3340 # Still somewhere in the midst of execution. Set up the
3342 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3343 # Perl 5 ones (sorry, we don't print Klingon
3346 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
3347 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
3348 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
3350 # Break up the prompt if it's really long.
3351 if ( length($self->prefix()) > 30 ) {
3352 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
3354 $self->infix(":\t");
3357 $self->infix("):\t");
3359 $self->prefix . $line. $self->infix
3360 . $self->_curr_line . $self->after
3364 # Print current line info, indenting if necessary.
3365 $self->_my_print_lineinfo($line, $self->position);
3368 my $line_i = sub { return $DB::dbline[$i]; };
3370 # Scan forward, stopping at either the end or the next
3372 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
3375 # Drop out on null statements, block closers, and comments.
3376 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
3378 # Drop out if the user interrupted us.
3381 # Append a newline if the line doesn't have one. Can happen
3382 # in eval'ed text, for instance.
3383 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
3385 # Next executable line.
3386 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
3388 $self->append_to_position($incr_pos);
3389 $self->_my_print_lineinfo($i, $incr_pos);
3390 } ## end for ($i = $line + 1 ; $i...
3391 } ## end else [ if ($slave_editor)
3396 sub _handle_t_command {
3399 my $levels = $self->cmd_args();
3401 if ((!length($levels)) or ($levels !~ /\D/)) {
3404 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3405 print {$OUT} "Trace = "
3407 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3416 sub _handle_S_command {
3419 if (my ($print_all_subs, $should_reverse, $Spatt)
3420 = $self->cmd_args =~ /\A((!)?(.+))?\z/) {
3421 # $Spatt is the pattern (if any) to use.
3423 my $Srev = defined $should_reverse;
3424 # No args - print all subs.
3425 my $Snocheck = !defined $print_all_subs;
3427 # Need to make these sane here.
3431 # Search through the debugger's magical hash of subs.
3432 # If $nocheck is true, just print the sub name.
3433 # Otherwise, check it against the pattern. We then use
3434 # the XOR trick to reverse the condition as required.
3435 foreach $subname ( sort( keys %sub ) ) {
3436 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3437 print $OUT $subname, "\n";
3446 sub _handle_V_command_and_X_command {
3449 $DB::cmd =~ s/^X\b/V $DB::package/;
3451 # Bare V commands get the currently-being-debugged package
3453 if ($self->_is_full('V')) {
3454 $DB::cmd = "V $DB::package";
3457 # V - show variables in package.
3458 if (my ($new_packname, $new_vars_str) =
3459 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3461 # Save the currently selected filehandle and
3462 # force output to debugger's filehandle (dumpvar
3463 # just does "print" for output).
3464 my $savout = select($OUT);
3466 # Grab package name and variables to dump.
3467 $packname = $new_packname;
3468 my @vars = split( ' ', $new_vars_str );
3470 # If main::dumpvar isn't here, get it.
3471 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3472 if ( defined &main::dumpvar ) {
3474 # We got it. Turn off subroutine entry/exit messages
3475 # for the moment, along with return values.
3479 # must detect sigpipe failures - not catching
3480 # then will cause the debugger to die.
3484 defined $option{dumpDepth}
3485 ? $option{dumpDepth}
3486 : -1, # assume -1 unless specified
3491 # The die doesn't need to include the $@, because
3492 # it will automatically get propagated for us.
3494 die unless $@ =~ /dumpvar print failed/;
3496 } ## end if (defined &main::dumpvar)
3499 # Couldn't load dumpvar.
3500 print $OUT "dumpvar.pl not available.\n";
3503 # Restore the output filehandle, and go round again.
3511 sub _handle_dash_command {
3514 if ($self->_is_full('-')) {
3516 # back up by a window; go to 1 if back too far.
3517 $start -= $incr + $window + 1;
3518 $start = 1 if $start <= 0;
3519 $incr = $window - 1;
3521 # Generate and execute a "l +" command (handled below).
3522 $DB::cmd = 'l ' . ($start) . '+';
3528 sub _n_or_s_commands_generic {
3529 my ($self, $new_val) = @_;
3531 next CMD if DB::_DB__is_finished();
3533 # Single step, but don't enter subs.
3536 # Save for empty command (repeat last).
3537 $laststep = $DB::cmd;
3542 my ($self, $letter, $new_val) = @_;
3544 if ($self->_is_full($letter)) {
3545 $self->_n_or_s_commands_generic($new_val);
3548 $self->_n_or_s_and_arg_commands_generic($letter, $new_val);
3554 sub _handle_n_command {
3557 return $self->_n_or_s('n', 2);
3560 sub _handle_s_command {
3563 return $self->_n_or_s('s', 1);
3566 sub _handle_r_command {
3569 # r - return from the current subroutine.
3570 if ($self->_is_full('r')) {
3572 # Can't do anything if the program's over.
3573 next CMD if DB::_DB__is_finished();
3575 # Turn on stack trace.
3576 $stack[$stack_depth] |= 1;
3578 # Print return value unless the stack is empty.
3579 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3586 sub _handle_T_command {
3589 if ($self->_is_full('T')) {
3590 DB::print_trace( $OUT, 1 ); # skip DB
3597 sub _handle_w_command {
3600 DB::cmd_w( 'w', $self->cmd_args() );
3606 sub _handle_W_command {
3609 if (my $arg = $self->cmd_args) {
3610 DB::cmd_W( 'W', $arg );
3617 sub _handle_rc_recall_command {
3620 # $rc - recall command.
3621 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3623 # No arguments, take one thing off history.
3624 pop(@hist) if length($DB::cmd) > 1;
3626 # Relative (- found)?
3627 # Y - index back from most recent (by 1 if bare minus)
3628 # N - go to that particular command slot or the last
3629 # thing if nothing following.
3632 scalar($minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist ))
3635 # Pick out the command desired.
3636 $DB::cmd = $hist[$self->cmd_verb];
3638 # Print the command to be executed and restart the loop
3639 # with that command in the buffer.
3640 print {$OUT} $DB::cmd, "\n";
3647 sub _handle_rc_search_history_command {
3650 # $rc pattern $rc - find a command in the history.
3651 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) {
3653 # Create the pattern to use.
3657 # Toss off last entry if length is >1 (and it always is).
3658 pop(@hist) if length($DB::cmd) > 1;
3662 # Look backward through the history.
3664 for ( $i = $#hist ; $i ; --$i ) {
3665 # Stop if we find it.
3666 last SEARCH_HIST if $hist[$i] =~ /$pat/;
3672 print $OUT "No such command!\n\n";
3676 # Found it. Put it in the buffer, print it, and process it.
3677 $DB::cmd = $hist[$i];
3678 print $OUT $DB::cmd, "\n";
3685 sub _handle_H_command {
3688 if ($self->cmd_args =~ m#\A\*#) {
3689 @hist = @truehist = ();
3690 print $OUT "History cleansed\n";
3694 if (my ($num) = $self->cmd_args =~ /\A(?:-(\d+))?/) {
3696 # Anything other than negative numbers is ignored by
3697 # the (incorrect) pattern, so this test does nothing.
3698 $end = $num ? ( $#hist - $num ) : 0;
3700 # Set to the minimum if less than zero.
3701 $hist = 0 if $hist < 0;
3703 # Start at the end of the array.
3704 # Stay in while we're still above the ending value.
3705 # Tick back by one each time around the loop.
3708 for ( $i = $#hist ; $i > $end ; $i-- ) {
3710 # Print the command unless it has no arguments.
3711 print $OUT "$i: ", $hist[$i], "\n"
3712 unless $hist[$i] =~ /^.?$/;
3721 sub _handle_doc_command {
3724 # man, perldoc, doc - show manual pages.
3726 = $DB::cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
3727 DB::runman($man_page);
3734 sub _handle_p_command {
3737 my $print_cmd = 'print {$DB::OUT} ';
3738 # p - print (no args): print $_.
3739 if ($self->_is_full('p')) {
3740 $DB::cmd = $print_cmd . '$_';
3743 # p - print the given expression.
3744 $DB::cmd =~ s/\Ap\b/$print_cmd /;
3750 sub _handle_equal_sign_command {
3753 if ($DB::cmd =~ s/\A=\s*//) {
3755 if ( length $DB::cmd == 0 ) {
3757 # No args, get current aliases.
3758 @keys = sort keys %alias;
3760 elsif ( my ( $k, $v ) = ( $DB::cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3762 # Creating a new alias. $k is alias name, $v is
3765 # can't use $_ or kill //g state
3766 for my $x ( $k, $v ) {
3768 # Escape "alarm" characters.
3772 # Substitute key for value, using alarm chars
3773 # as separators (which is why we escaped them in
3775 $alias{$k} = "s\a$k\a$v\a";
3777 # Turn off standard warn and die behavior.
3778 local $SIG{__DIE__};
3779 local $SIG{__WARN__};
3782 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3784 # Nope. Bad alias. Say so and get out.
3785 print $OUT "Can't alias $k to $v: $@\n";
3790 # We'll only list the new one.
3792 } ## end elsif (my ($k, $v) = ($DB::cmd...
3794 # The argument is the alias to list.
3802 # Messy metaquoting: Trim the substitution code off.
3803 # We use control-G as the delimiter because it's not
3804 # likely to appear in the alias.
3805 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3808 print $OUT "$k\t= $1\n";
3810 elsif ( defined $alias{$k} ) {
3812 # Couldn't trim it off; just print the alias code.
3813 print $OUT "$k\t$alias{$k}\n";
3818 print "No alias for $k\n";
3820 } ## end for my $k (@keys)
3827 sub _handle_source_command {
3830 # source - read commands from a file (or pipe!) and execute.
3831 if (my $sourced_fn = $self->cmd_args) {
3832 if ( open my $fh, $sourced_fn ) {
3834 # Opened OK; stick it in the list of file handles.
3840 DB::_db_warn("Can't execute '$sourced_fn': $!\n");
3848 sub _handle_enable_disable_commands {
3851 my $which_cmd = $self->cmd_verb;
3852 my $position = $self->cmd_args;
3854 if ($position !~ /\s/) {
3855 my ($fn, $line_num);
3856 if ($position =~ m{\A\d+\z})
3858 $fn = $DB::filename;
3859 $line_num = $position;
3861 elsif (my ($new_fn, $new_line_num)
3862 = $position =~ m{\A(.*):(\d+)\z}) {
3863 ($fn, $line_num) = ($new_fn, $new_line_num);
3867 DB::_db_warn("Wrong spec for enable/disable argument.\n");
3871 if (DB::_has_breakpoint_data_ref($fn, $line_num)) {
3872 DB::_set_breakpoint_enabled_status($fn, $line_num,
3873 ($which_cmd eq 'enable' ? 1 : '')
3877 DB::_db_warn("No breakpoint set at ${fn}:${line_num}\n");
3887 sub _handle_save_command {
3890 if (my $new_fn = $self->cmd_args) {
3891 my $filename = $new_fn || '.perl5dbrc'; # default?
3892 if ( open my $fh, '>', $filename ) {
3894 # chomp to remove extraneous newlines from source'd files
3895 chomp( my @truelist =
3896 map { m/\A\s*(save|source)/ ? "#$_" : $_ }
3898 print {$fh} join( "\n", @truelist );
3899 print "commands saved in $filename\n";
3902 DB::_db_warn("Can't save debugger commands in '$new_fn': $!\n");
3910 sub _n_or_s_and_arg_commands_generic {
3911 my ($self, $letter, $new_val) = @_;
3913 # s - single-step. Remember the last command was 's'.
3914 if ($DB::cmd =~ s#\A\Q$letter\E\s#\$DB::single = $new_val;\n#) {
3915 $laststep = $letter;
3921 sub _handle_sh_command {
3924 # $sh$sh - run a shell command (if it's all ASCII).
3925 # Can't run shell commands with Unicode in the debugger, hmm.
3926 my $my_cmd = $DB::cmd;
3927 if ($my_cmd =~ m#\A$sh#gms) {
3929 if ($my_cmd =~ m#\G\z#cgms) {
3930 # Run the user's shell. If none defined, run Bourne.
3931 # We resume execution when the shell terminates.
3932 DB::_db_system( $ENV{SHELL} || "/bin/sh" );
3935 elsif ($my_cmd =~ m#\G$sh\s*(.*)#cgms) {
3940 elsif ($my_cmd =~ m#\G\s*(.*)#cgms) {
3941 DB::_db_system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3947 sub _handle_x_command {
3950 if ($DB::cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
3951 $onetimeDump = 'dump'; # main::dumpvar shows the output
3953 # handle special "x 3 blah" syntax XXX propagate
3954 # doc back to special variables.
3955 if ( $DB::cmd =~ s#\A\s*(\d+)(?=\s)# #) {
3956 $onetimedumpDepth = $1;
3963 sub _handle_q_command {
3966 if ($self->_is_full('q')) {
3975 sub _handle_cmd_wrapper_commands {
3978 DB::cmd_wrapper( $self->cmd_verb, $self->cmd_args, $line );
3982 sub _handle_special_char_cmd_wrapper_commands {
3985 # All of these commands were remapped in perl 5.8.0;
3986 # we send them off to the secondary dispatcher (see below).
3987 if (my ($cmd_letter, $my_arg) = $DB::cmd =~ /\A([<>\{]{1,2})\s*(.*)/so) {
3988 DB::cmd_wrapper( $cmd_letter, $my_arg, $line );
3999 # The following code may be executed now:
4004 C<sub> is called whenever a subroutine call happens in the program being
4005 debugged. The variable C<$DB::sub> contains the name of the subroutine
4008 The core function of this subroutine is to actually call the sub in the proper
4009 context, capturing its output. This of course causes C<DB::DB> to get called
4010 again, repeating until the subroutine ends and returns control to C<DB::sub>
4011 again. Once control returns, C<DB::sub> figures out whether or not to dump the
4012 return value, and returns its captured copy of the return value as its own
4013 return value. The value then feeds back into the program being debugged as if
4014 C<DB::sub> hadn't been there at all.
4016 C<sub> does all the work of printing the subroutine entry and exit messages
4017 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
4018 and also prints the return value if needed (for the C<r> command and if
4019 the 16 bit is set in C<$frame>).
4021 It also tracks the subroutine call depth by saving the current setting of
4022 C<$single> in the C<@stack> package global; if this exceeds the value in
4023 C<$deep>, C<sub> automatically turns on printing of the current depth by
4024 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
4025 of stop/don't stop on entry to subs set as it currently is set.
4027 =head3 C<caller()> support
4029 If C<caller()> is called from the package C<DB>, it provides some
4030 additional data, in the following order:
4036 The package name the sub was in
4038 =item * C<$filename>
4040 The filename it was defined in
4044 The line number it was defined on
4046 =item * C<$subroutine>
4048 The subroutine name; C<(eval)> if an C<eval>().
4052 1 if it has arguments, 0 if not
4054 =item * C<$wantarray>
4056 1 if array context, 0 if scalar context
4058 =item * C<$evaltext>
4060 The C<eval>() text, if any (undefined for C<eval BLOCK>)
4062 =item * C<$is_require>
4064 frame was created by a C<use> or C<require> statement
4068 pragma information; subject to change between versions
4072 pragma information; subject to change between versions
4074 =item * C<@DB::args>
4076 arguments with which the subroutine was invoked
4084 # We need to fully qualify the name ("DB::sub") to make "use strict;"
4085 # happy. -- Shlomi Fish
4087 sub _indent_print_line_info {
4088 my ($offset, $str) = @_;
4090 print_lineinfo( ' ' x ($stack_depth - $offset), $str);
4095 sub _print_frame_message {
4099 if ($frame & 4) { # Extended frame entry message
4100 _indent_print_line_info(-1, "in ");
4102 # Why -1? But it works! :-(
4103 # Because print_trace will call add 1 to it and then call
4104 # dump_trace; this results in our skipping -1+1 = 0 stack frames
4107 # Now it's 0 because we extracted a function.
4108 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" );
4111 _indent_print_line_info(-1, "entering $sub$al\n" );
4119 # lock ourselves under threads
4122 # Whether or not the autoloader was running, a scalar to put the
4123 # sub's return value in (if needed), and an array to put the sub's
4124 # return value in (if needed).
4125 my ( $al, $ret, @ret ) = "";
4126 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
4127 print "creating new thread\n";
4130 # If the last ten characters are '::AUTOLOAD', note we've traced
4131 # into AUTOLOAD for $sub.
4132 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4134 $al = " for $$sub" if defined $$sub;
4137 # We stack the stack pointer and then increment it to protect us
4138 # from a situation that might unwind a whole bunch of call frames
4139 # at once. Localizing the stack pointer means that it will automatically
4140 # unwind the same amount when multiple stack frames are unwound.
4141 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4144 $#stack = $stack_depth;
4146 # Save current single-step setting.
4147 $stack[-1] = $single;
4149 # Turn off all flags except single-stepping.
4152 # If we've gotten really deeply recursed, turn on the flag that will
4153 # make us stop with the 'deep recursion' message.
4154 $single |= 4 if $stack_depth == $deep;
4156 # If frame messages are on ...
4158 _print_frame_message($al);
4159 # standard frame entry message
4161 my $print_exit_msg = sub {
4162 # Check for exit trace messages...
4165 if ($frame & 4) # Extended exit message
4167 _indent_print_line_info(0, "out ");
4168 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" );
4172 _indent_print_line_info(0, "exited $sub$al\n" );
4178 # Determine the sub's return type, and capture appropriately.
4181 # Called in array context. call sub and capture output.
4182 # DB::DB will recursively get control again if appropriate; we'll come
4183 # back here when the sub is finished.
4189 # Pop the single-step value back off the stack.
4190 $single |= $stack[ $stack_depth-- ];
4192 $print_exit_msg->();
4194 # Print the return info if we need to.
4195 if ( $doret eq $stack_depth or $frame & 16 ) {
4197 # Turn off output record separator.
4199 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4201 # Indent if we're printing because of $frame tracing.
4204 print {$fh} ' ' x $stack_depth;
4207 # Print the return value.
4208 print {$fh} "list context return from $sub:\n";
4209 dumpit( $fh, \@ret );
4211 # And don't print it again.
4213 } ## end if ($doret eq $stack_depth...
4214 # And we have to return the return value now.
4216 } ## end if (wantarray)
4220 if ( defined wantarray ) {
4222 # Save the value if it's wanted at all.
4227 # Void return, explicitly.
4232 # Pop the single-step value off the stack.
4233 $single |= $stack[ $stack_depth-- ];
4235 # If we're doing exit messages...
4236 $print_exit_msg->();
4238 # If we are supposed to show the return value... same as before.
4239 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
4241 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4242 print $fh ( ' ' x $stack_depth ) if $frame & 16;
4245 ? "scalar context return from $sub: "
4246 : "void context return from $sub\n"
4248 dumpit( $fh, $ret ) if defined wantarray;
4250 } ## end if ($doret eq $stack_depth...
4252 # Return the appropriate scalar value.
4254 } ## end else [ if (wantarray)
4261 # lock ourselves under threads
4264 # Whether or not the autoloader was running, a scalar to put the
4265 # sub's return value in (if needed), and an array to put the sub's
4266 # return value in (if needed).
4267 my ( $al, $ret, @ret ) = "";
4268 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
4269 print "creating new thread\n";
4272 # If the last ten characters are C'::AUTOLOAD', note we've traced
4273 # into AUTOLOAD for $sub.
4274 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4278 # We stack the stack pointer and then increment it to protect us
4279 # from a situation that might unwind a whole bunch of call frames
4280 # at once. Localizing the stack pointer means that it will automatically
4281 # unwind the same amount when multiple stack frames are unwound.
4282 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4285 $#stack = $stack_depth;
4287 # Save current single-step setting.
4288 $stack[-1] = $single;
4290 # Turn off all flags except single-stepping.
4291 # Use local so the single-step value is popped back off the
4293 local $single = $single & 1;
4295 # If we've gotten really deeply recursed, turn on the flag that will
4296 # make us stop with the 'deep recursion' message.
4297 $single |= 4 if $stack_depth == $deep;
4299 # If frame messages are on ...
4300 _print_frame_message($al);
4302 # call the original lvalue sub.
4306 # Abstracting common code from multiple places elsewhere:
4307 sub depth_print_lineinfo {
4308 my $always_print = shift;
4310 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth);
4313 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
4315 In Perl 5.8.0, there was a major realignment of the commands and what they did,
4316 Most of the changes were to systematize the command structure and to eliminate
4317 commands that threw away user input without checking.
4319 The following sections describe the code added to make it easy to support
4320 multiple command sets with conflicting command names. This section is a start
4321 at unifying all command processing to make it simpler to develop commands.
4323 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
4324 number, and C<$dbline> (the current line) as arguments.
4326 Support functions in this section which have multiple modes of failure C<die>
4327 on error; the rest simply return a false value.
4329 The user-interface functions (all of the C<cmd_*> functions) just output
4334 The C<%set> hash defines the mapping from command letter to subroutine
4337 C<%set> is a two-level hash, indexed by set name and then by command name.
4338 Note that trying to set the CommandSet to C<foobar> simply results in the
4339 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
4348 'A' => 'pre580_null',
4350 'B' => 'pre580_null',
4351 'd' => 'pre580_null',
4354 'M' => 'pre580_null',
4356 'o' => 'pre580_null',
4362 '<' => 'pre590_prepost',
4363 '<<' => 'pre590_prepost',
4364 '>' => 'pre590_prepost',
4365 '>>' => 'pre590_prepost',
4366 '{' => 'pre590_prepost',
4367 '{{' => 'pre590_prepost',
4371 my %breakpoints_data;
4373 sub _has_breakpoint_data_ref {
4374 my ($filename, $line) = @_;
4377 exists( $breakpoints_data{$filename} )
4379 exists( $breakpoints_data{$filename}{$line} )
4383 sub _get_breakpoint_data_ref {
4384 my ($filename, $line) = @_;
4386 return ($breakpoints_data{$filename}{$line} ||= +{});
4389 sub _delete_breakpoint_data_ref {
4390 my ($filename, $line) = @_;
4392 delete($breakpoints_data{$filename}{$line});
4393 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) {
4394 delete($breakpoints_data{$filename});
4400 sub _set_breakpoint_enabled_status {
4401 my ($filename, $line, $status) = @_;
4403 _get_breakpoint_data_ref($filename, $line)->{'enabled'} =
4410 sub _enable_breakpoint_temp_enabled_status {
4411 my ($filename, $line) = @_;
4413 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1;
4418 sub _cancel_breakpoint_temp_enabled_status {
4419 my ($filename, $line) = @_;
4421 my $ref = _get_breakpoint_data_ref($filename, $line);
4423 delete ($ref->{'temp_enabled'});
4426 _delete_breakpoint_data_ref($filename, $line);
4432 sub _is_breakpoint_enabled {
4433 my ($filename, $line) = @_;
4435 my $data_ref = _get_breakpoint_data_ref($filename, $line);
4436 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'});
4439 =head2 C<cmd_wrapper()> (API)
4441 C<cmd_wrapper()> allows the debugger to switch command sets
4442 depending on the value of the C<CommandSet> option.
4444 It tries to look up the command in the C<%set> package-level I<lexical>
4445 (which means external entities can't fiddle with it) and create the name of
4446 the sub to call based on the value found in the hash (if it's there). I<All>
4447 of the commands to be handled in a set have to be added to C<%set>; if they
4448 aren't found, the 5.8.0 equivalent is called (if there is one).
4450 This code uses symbolic references.
4457 my $dblineno = shift;
4459 # Assemble the command subroutine's name by looking up the
4460 # command set and command name in %set. If we can't find it,
4461 # default to the older version of the command.
4463 . ( $set{$CommandSet}{$cmd}
4464 || ( $cmd =~ /\A[<>{]+/o ? 'prepost' : $cmd ) );
4466 # Call the command subroutine, call it by name.
4467 return __PACKAGE__->can($call)->( $cmd, $line, $dblineno );
4468 } ## end sub cmd_wrapper
4470 =head3 C<cmd_a> (command)
4472 The C<a> command handles pre-execution actions. These are associated with a
4473 particular line, so they're stored in C<%dbline>. We default to the current
4474 line if none is specified.
4480 my $line = shift || ''; # [.|line] expr
4483 # If it's dot (here), or not all digits, use the current line.
4484 $line =~ s/\A\./$dbline/;
4486 # Should be a line number followed by an expression.
4487 if ( my ($lineno, $expr) = $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
4489 if (! length($lineno)) {
4493 # If we have an expression ...
4494 if ( length $expr ) {
4496 # ... but the line isn't breakable, complain.
4497 if ( $dbline[$lineno] == 0 ) {
4499 "Line $lineno($dbline[$lineno]) does not have an action?\n";
4503 # It's executable. Record that the line has an action.
4504 $had_breakpoints{$filename} |= 2;
4506 # Remove any action, temp breakpoint, etc.
4507 $dbline{$lineno} =~ s/\0[^\0]*//;
4509 # Add the action to the line.
4510 $dbline{$lineno} .= "\0" . action($expr);
4512 _set_breakpoint_enabled_status($filename, $lineno, 1);
4514 } ## end if (length $expr)
4515 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
4520 "Adding an action requires an optional lineno and an expression\n"
4525 =head3 C<cmd_A> (command)
4527 Delete actions. Similar to above, except the delete code is in a separate
4528 subroutine, C<delete_action>.
4534 my $line = shift || '';
4538 $line =~ s/^\./$dbline/;
4540 # Call delete_action with a null param to delete them all.
4541 # The '1' forces the eval to be true. It'll be false only
4542 # if delete_action blows up for some reason, in which case
4543 # we print $@ and get out.
4544 if ( $line eq '*' ) {
4545 if (! eval { _delete_all_actions(); 1 }) {
4551 # There's a real line number. Pass it to delete_action.
4552 # Error trapping is as above.
4553 elsif ( $line =~ /^(\S.*)/ ) {
4554 if (! eval { delete_action($1); 1 }) {
4560 # Swing and a miss. Bad syntax.
4563 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4567 =head3 C<delete_action> (API)
4569 C<delete_action> accepts either a line number or C<undef>. If a line number
4570 is specified, we check for the line being executable (if it's not, it
4571 couldn't have had an action). If it is, we just take the action off (this
4572 will get any kind of an action, including breakpoints).
4576 sub _remove_action_from_dbline {
4579 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4580 delete $dbline{$i} if $dbline{$i} eq '';
4585 sub _delete_all_actions {
4586 print {$OUT} "Deleting all actions...\n";
4588 for my $file ( keys %had_breakpoints ) {
4589 local *dbline = $main::{ '_<' . $file };
4592 for my $i (1 .. $max) {
4593 if ( defined $dbline{$i} ) {
4594 _remove_action_from_dbline($i);
4598 unless ( $had_breakpoints{$file} &= ~2 ) {
4599 delete $had_breakpoints{$file};
4609 if ( defined($i) ) {
4611 die "Line $i has no action .\n" if $dbline[$i] == 0;
4613 # Nuke whatever's there.
4614 _remove_action_from_dbline($i);
4617 _delete_all_actions();
4621 =head3 C<cmd_b> (command)
4623 Set breakpoints. Since breakpoints can be set in so many places, in so many
4624 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4625 we try to parse the command type, and then shuttle it off to an appropriate
4626 subroutine to actually do the work of setting the breakpoint in the right
4633 my $line = shift; # [.|line] [cond]
4636 my $default_cond = sub {
4638 return length($cond) ? $cond : '1';
4641 # Make . the current line number if it's there..
4642 $line =~ s/^\.(\s|\z)/$dbline$1/;
4644 # No line number, no condition. Simple break on current line.
4645 if ( $line =~ /^\s*$/ ) {
4646 cmd_b_line( $dbline, 1 );
4649 # Break on load for a file.
4650 elsif ( my ($file) = $line =~ /^load\b\s*(.*)/ ) {
4655 # b compile|postpone <some sub> [<condition>]
4656 # The interpreter actually traps this one for us; we just put the
4657 # necessary condition in the %postponed hash.
4658 elsif ( my ($action, $subname, $cond)
4659 = $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4661 # De-Perl4-ify the name - ' separators to ::.
4662 $subname =~ s/'/::/g;
4664 # Qualify it into the current package unless it's already qualified.
4665 $subname = "${package}::" . $subname unless $subname =~ /::/;
4667 # Add main if it starts with ::.
4668 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4670 # Save the break type for this sub.
4671 $postponed{$subname} = (($action eq 'postpone')
4672 ? ( "break +0 if " . $default_cond->($cond) )
4674 } ## end elsif ($line =~ ...
4675 # b <filename>:<line> [<condition>]
4676 elsif (my ($filename, $line_num, $cond)
4677 = $line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) {
4678 cmd_b_filename_line(
4681 (length($cond) ? $cond : '1'),
4684 # b <sub name> [<condition>]
4685 elsif ( my ($new_subname, $new_cond) =
4686 $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4689 $subname = $new_subname;
4690 cmd_b_sub( $subname, $default_cond->($new_cond) );
4693 # b <line> [<condition>].
4694 elsif ( my ($line_n, $cond) = $line =~ /^(\d*)\s*(.*)/ ) {
4696 # Capture the line. If none, it's the current line.
4697 $line = $line_n || $dbline;
4700 cmd_b_line( $line, $default_cond->($cond) );
4703 # Line didn't make sense.
4705 print "confused by line($line)?\n";
4711 =head3 C<break_on_load> (API)
4713 We want to break when this file is loaded. Mark this file in the
4714 C<%break_on_load> hash, and note that it has a breakpoint in
4715 C<%had_breakpoints>.
4721 $break_on_load{$file} = 1;
4722 $had_breakpoints{$file} |= 1;
4725 =head3 C<report_break_on_load> (API)
4727 Gives us an array of filenames that are set to break on load. Note that
4728 only files with break-on-load are in here, so simply showing the keys
4733 sub report_break_on_load {
4734 sort keys %break_on_load;
4737 =head3 C<cmd_b_load> (command)
4739 We take the file passed in and try to find it in C<%INC> (which maps modules
4740 to files they came from). We mark those files for break-on-load via
4741 C<break_on_load> and then report that it was done.
4749 # This is a block because that way we can use a redo inside it
4750 # even without there being any looping structure at all outside it.
4753 # Save short name and full path if found.
4755 push @files, $::INC{$file} if $::INC{$file};
4757 # Tack on .pm and do it again unless there was a '.' in the name
4759 $file .= '.pm', redo unless $file =~ /\./;
4762 # Do the real work here.
4763 break_on_load($_) for @files;
4765 # All the files that have break-on-load breakpoints.
4766 @files = report_break_on_load;
4768 # Normalize for the purposes of our printing this.
4771 print $OUT "Will stop on load of '@files'.\n";
4772 } ## end sub cmd_b_load
4774 =head3 C<$filename_error> (API package global)
4776 Several of the functions we need to implement in the API need to work both
4777 on the current file and on other files. We don't want to duplicate code, so
4778 C<$filename_error> is used to contain the name of the file that's being
4779 worked on (if it's not the current one).
4781 We can now build functions in pairs: the basic function works on the current
4782 file, and uses C<$filename_error> as part of its error message. Since this is
4783 initialized to C<"">, no filename will appear when we are working on the
4786 The second function is a wrapper which does the following:
4792 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4796 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4800 Calls the first function.
4802 The first function works on the I<current> file (i.e., the one we changed to),
4803 and prints C<$filename_error> in the error message (the name of the other file)
4804 if it needs to. When the functions return, C<*dbline> is restored to point
4805 to the actual current file (the one we're executing in) and
4806 C<$filename_error> is restored to C<"">. This restores everything to
4807 the way it was before the second function was called at all.
4809 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4816 use vars qw($filename_error);
4817 $filename_error = '';
4819 =head3 breakable_line(from, to) (API)
4821 The subroutine decides whether or not a line in the current file is breakable.
4822 It walks through C<@dbline> within the range of lines specified, looking for
4823 the first line that is breakable.
4825 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4826 first line I<after> C<$to> that's breakable, if there is one.
4828 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4829 first line I<before> C<$to> that's breakable, if there is one.
4833 sub breakable_line {
4835 my ( $from, $to ) = @_;
4837 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4840 # If there are at least 2 arguments, we're trying to search a range.
4843 # $delta is positive for a forward search, negative for a backward one.
4844 my $delta = $from < $to ? +1 : -1;
4846 # Keep us from running off the ends of the file.
4847 my $limit = $delta > 0 ? $#dbline : 1;
4849 # Clever test. If you're a mathematician, it's obvious why this
4850 # test works. If not:
4851 # If $delta is positive (going forward), $limit will be $#dbline.
4852 # If $to is less than $limit, ($limit - $to) will be positive, times
4853 # $delta of 1 (positive), so the result is > 0 and we should use $to
4854 # as the stopping point.
4856 # If $to is greater than $limit, ($limit - $to) is negative,
4857 # times $delta of 1 (positive), so the result is < 0 and we should
4858 # use $limit ($#dbline) as the stopping point.
4860 # If $delta is negative (going backward), $limit will be 1.
4861 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4862 # (negative) so the result is > 0, and we use $to as the stopping
4865 # If $to is less than zero, ($limit - $to) will be positive,
4866 # times $delta of -1 (negative), so the result is not > 0, and
4867 # we use $limit (1) as the stopping point.
4869 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4870 # (negative), still giving zero; the result is not > 0, and
4871 # we use $limit (1) as the stopping point.
4873 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4874 # (negative), giving a positive (>0) value, so we'll set $limit to
4877 $limit = $to if ( $limit - $to ) * $delta > 0;
4879 # The real search loop.
4880 # $i starts at $from (the point we want to start searching from).
4881 # We move through @dbline in the appropriate direction (determined
4882 # by $delta: either -1 (back) or +1 (ahead).
4883 # We stay in as long as we haven't hit an executable line
4884 # ($dbline[$i] == 0 means not executable) and we haven't reached
4885 # the limit yet (test similar to the above).
4886 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4888 } ## end if (@_ >= 2)
4890 # If $i points to a line that is executable, return that.
4891 return $i unless $dbline[$i] == 0;
4893 # Format the message and print it: no breakable lines in range.
4894 my ( $pl, $upto ) = ( '', '' );
4895 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4897 # If there's a filename in filename_error, we'll see it.
4899 die "Line$pl $from$upto$filename_error not breakable\n";
4900 } ## end sub breakable_line
4902 =head3 breakable_line_in_filename(file, from, to) (API)
4904 Like C<breakable_line>, but look in another file.
4908 sub breakable_line_in_filename {
4910 # Capture the file name.
4913 # Swap the magic line array over there temporarily.
4914 local *dbline = $main::{ '_<' . $f };
4916 # If there's an error, it's in this other file.
4917 local $filename_error = " of '$f'";
4919 # Find the breakable line.
4922 # *dbline and $filename_error get restored when this block ends.
4924 } ## end sub breakable_line_in_filename
4926 =head3 break_on_line(lineno, [condition]) (API)
4928 Adds a breakpoint with the specified condition (or 1 if no condition was
4929 specified) to the specified line. Dies if it can't.
4935 my $cond = @_ ? shift(@_) : 1;
4941 # Woops, not a breakable line. $filename_error allows us to say
4942 # if it was in a different file.
4943 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4945 # Mark this file as having breakpoints in it.
4946 $had_breakpoints{$filename} |= 1;
4948 # If there is an action or condition here already ...
4949 if ( $dbline{$i} ) {
4951 # ... swap this condition for the existing one.
4952 $dbline{$i} =~ s/^[^\0]*/$cond/;
4956 # Nothing here - just add the condition.
4957 $dbline{$i} = $cond;
4959 _set_breakpoint_enabled_status($filename, $i, 1);
4963 } ## end sub break_on_line
4965 =head3 cmd_b_line(line, [condition]) (command)
4967 Wrapper for C<break_on_line>. Prints the failure message if it
4973 if (not eval { break_on_line(@_); 1 }) {
4975 print $OUT $@ and return;
4979 } ## end sub cmd_b_line
4981 =head3 cmd_b_filename_line(line, [condition]) (command)
4983 Wrapper for C<break_on_filename_line>. Prints the failure message if it
4988 sub cmd_b_filename_line {
4989 if (not eval { break_on_filename_line(@_); 1 }) {
4991 print $OUT $@ and return;
4997 =head3 break_on_filename_line(file, line, [condition]) (API)
4999 Switches to the file specified and then calls C<break_on_line> to set
5004 sub break_on_filename_line {
5007 my $cond = @_ ? shift(@_) : 1;
5009 # Switch the magical hash temporarily.
5010 local *dbline = $main::{ '_<' . $f };
5012 # Localize the variables that break_on_line uses to make its message.
5013 local $filename_error = " of '$f'";
5014 local $filename = $f;
5016 # Add the breakpoint.
5017 break_on_line( $i, $cond );
5020 } ## end sub break_on_filename_line
5022 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
5024 Switch to another file, search the range of lines specified for an
5025 executable one, and put a breakpoint on the first one you find.
5029 sub break_on_filename_line_range {
5033 my $cond = @_ ? shift(@_) : 1;
5035 # Find a breakable line if there is one.
5036 my $i = breakable_line_in_filename( $f, $from, $to );
5038 # Add the breakpoint.
5039 break_on_filename_line( $f, $i, $cond );
5042 } ## end sub break_on_filename_line_range
5044 =head3 subroutine_filename_lines(subname, [condition]) (API)
5046 Search for a subroutine within a given file. The condition is ignored.
5047 Uses C<find_sub> to locate the desired subroutine.
5051 sub subroutine_filename_lines {
5052 my ( $subname ) = @_;
5054 # Returned value from find_sub() is fullpathname:startline-endline.
5055 # The match creates the list (fullpathname, start, end).
5056 return (find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/);
5057 } ## end sub subroutine_filename_lines
5059 =head3 break_subroutine(subname) (API)
5061 Places a break on the first line possible in the specified subroutine. Uses
5062 C<subroutine_filename_lines> to find the subroutine, and
5063 C<break_on_filename_line_range> to place the break.
5067 sub break_subroutine {
5068 my $subname = shift;
5070 # Get filename, start, and end.
5071 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
5072 or die "Subroutine $subname not found.\n";
5075 # Null condition changes to '1' (always true).
5076 my $cond = @_ ? shift(@_) : 1;
5078 # Put a break the first place possible in the range of lines
5079 # that make up this subroutine.
5080 break_on_filename_line_range( $file, $s, $e, $cond );
5083 } ## end sub break_subroutine
5085 =head3 cmd_b_sub(subname, [condition]) (command)
5087 We take the incoming subroutine name and fully-qualify it as best we can.
5091 =item 1. If it's already fully-qualified, leave it alone.
5093 =item 2. Try putting it in the current package.
5095 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
5097 =item 4. If it starts with '::', put it in 'main::'.
5101 After all this cleanup, we call C<break_subroutine> to try to set the
5107 my $subname = shift;
5108 my $cond = @_ ? shift : 1;
5110 # If the subname isn't a code reference, qualify it so that
5111 # break_subroutine() will work right.
5112 if ( ref($subname) ne 'CODE' ) {
5115 $subname =~ s/'/::/g;
5118 # Put it in this package unless it's already qualified.
5119 if ($subname !~ /::/)
5121 $subname = $package . '::' . $subname;
5124 # Requalify it into CORE::GLOBAL if qualifying it into this
5125 # package resulted in its not being defined, but only do so
5126 # if it really is in CORE::GLOBAL.
5127 my $core_name = "CORE::GLOBAL::$s";
5128 if ((!defined(&$subname))
5130 and (defined &{$core_name}))
5132 $subname = $core_name;
5135 # Put it in package 'main' if it has a leading ::.
5136 if ($subname =~ /\A::/)
5138 $subname = "main" . $subname;
5140 } ## end if ( ref($subname) ne 'CODE' ) {
5142 # Try to set the breakpoint.
5143 if (not eval { break_subroutine( $subname, $cond ); 1 }) {
5150 } ## end sub cmd_b_sub
5152 =head3 C<cmd_B> - delete breakpoint(s) (command)
5154 The command mostly parses the command line and tries to turn the argument
5155 into a line spec. If it can't, it uses the current line. It then calls
5156 C<delete_breakpoint> to actually do the work.
5158 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
5159 thereby deleting all the breakpoints.
5166 # No line spec? Use dbline.
5167 # If there is one, use it if it's non-zero, or wipe it out if it is.
5168 my $line = ( $_[0] =~ /\A\./ ) ? $dbline : (shift || '');
5171 # If the line was dot, make the line the current one.
5172 $line =~ s/^\./$dbline/;
5174 # If it's * we're deleting all the breakpoints.
5175 if ( $line eq '*' ) {
5176 if (not eval { delete_breakpoint(); 1 }) {
5181 # If there is a line spec, delete the breakpoint on that line.
5182 elsif ( $line =~ /\A(\S.*)/ ) {
5183 if (not eval { delete_breakpoint( $line || $dbline ); 1 }) {
5187 } ## end elsif ($line =~ /^(\S.*)/)
5192 "Deleting a breakpoint requires a line number, or '*' for all\n"
5199 =head3 delete_breakpoint([line]) (API)
5201 This actually does the work of deleting either a single breakpoint, or all
5204 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
5205 just drop out with a message saying so. If it is, we remove the condition
5206 part of the 'condition\0action' that says there's a breakpoint here. If,
5207 after we've done that, there's nothing left, we delete the corresponding
5208 line in C<%dbline> to signal that no action needs to be taken for this line.
5210 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
5211 which lists all currently-loaded files which have breakpoints. We then look
5212 at each line in each of these files, temporarily switching the C<%dbline>
5213 and C<@dbline> structures to point to the files in question, and do what
5214 we did in the single line case: delete the condition in C<@dbline>, and
5215 delete the key in C<%dbline> if nothing's left.
5217 We then wholesale delete C<%postponed>, C<%postponed_file>, and
5218 C<%break_on_load>, because these structures contain breakpoints for files
5219 and code that haven't been loaded yet. We can just kill these off because there
5220 are no magical debugger structures associated with them.
5224 sub _remove_breakpoint_entry {
5228 _delete_breakpoint_data_ref($fn, $i);
5233 sub _delete_all_breakpoints {
5234 print {$OUT} "Deleting all breakpoints...\n";
5236 # %had_breakpoints lists every file that had at least one
5238 for my $fn ( keys %had_breakpoints ) {
5240 # Switch to the desired file temporarily.
5241 local *dbline = $main::{ '_<' . $fn };
5245 # For all lines in this file ...
5246 for my $i (1 .. $max) {
5248 # If there's a breakpoint or action on this line ...
5249 if ( defined $dbline{$i} ) {
5251 # ... remove the breakpoint.
5252 $dbline{$i} =~ s/\A[^\0]+//;
5253 if ( $dbline{$i} =~ s/\A\0?\z// ) {
5254 # Remove the entry altogether if no action is there.
5255 _remove_breakpoint_entry($fn, $i);
5257 } ## end if (defined $dbline{$i...
5258 } ## end for $i (1 .. $max)
5260 # If, after we turn off the "there were breakpoints in this file"
5261 # bit, the entry in %had_breakpoints for this file is zero,
5262 # we should remove this file from the hash.
5263 if ( not $had_breakpoints{$fn} &= (~1) ) {
5264 delete $had_breakpoints{$fn};
5266 } ## end for my $fn (keys %had_breakpoints)
5268 # Kill off all the other breakpoints that are waiting for files that
5269 # haven't been loaded yet.
5271 undef %postponed_file;
5272 undef %break_on_load;
5277 sub _delete_breakpoint_from_line {
5280 # Woops. This line wasn't breakable at all.
5281 die "Line $i not breakable.\n" if $dbline[$i] == 0;
5283 # Kill the condition, but leave any action.
5284 $dbline{$i} =~ s/\A[^\0]*//;
5286 # Remove the entry entirely if there's no action left.
5287 if ($dbline{$i} eq '') {
5288 _remove_breakpoint_entry($filename, $i);
5294 sub delete_breakpoint {
5297 # If we got a line, delete just that one.
5298 if ( defined($i) ) {
5299 _delete_breakpoint_from_line($i);
5301 # No line; delete them all.
5303 _delete_all_breakpoints();
5309 =head3 cmd_stop (command)
5311 This is meant to be part of the new command API, but it isn't called or used
5312 anywhere else in the debugger. XXX It is probably meant for use in development
5317 sub cmd_stop { # As on ^C, but not signal-safy.
5321 =head3 C<cmd_e> - threads
5323 Display the current thread id:
5327 This could be how (when implemented) to send commands to this thread id (e cmd)
5328 or that thread id (e tid cmd).
5335 unless (exists($INC{'threads.pm'})) {
5336 print "threads not loaded($ENV{PERL5DB_THREADED})
5337 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5339 my $tid = threads->tid;
5340 print "thread id: $tid\n";
5344 =head3 C<cmd_E> - list of thread ids
5346 Display the list of available thread ids:
5350 This could be used (when implemented) to send commands to all threads (E cmd).
5357 unless (exists($INC{'threads.pm'})) {
5358 print "threads not loaded($ENV{PERL5DB_THREADED})
5359 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5361 my $tid = threads->tid;
5362 print "thread ids: ".join(', ',
5363 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
5368 =head3 C<cmd_h> - help command (command)
5370 Does the work of either
5376 Showing all the debugger help
5380 Showing help for a specific command
5387 use vars qw($summary);
5392 # If we have no operand, assume null.
5393 my $line = shift || '';
5395 # 'h h'. Print the long-format help.
5396 if ( $line =~ /\Ah\s*\z/ ) {
5400 # 'h <something>'. Search for the command and print only its help.
5401 elsif ( my ($asked) = $line =~ /\A(\S.*)\z/ ) {
5403 # support long commands; otherwise bogus errors
5404 # happen when you ask for h on <CR> for example
5405 my $qasked = quotemeta($asked); # for searching; we don't
5406 # want to use it as a pattern.
5407 # XXX: finds CR but not <CR>
5409 # Search the help string for the command.
5411 $help =~ /^ # Start of a line
5413 (?:[IB]<) # Optional markup
5414 $qasked # The requested command
5419 # It's there; pull it out and print it.
5423 (?:[IB]<) # Optional markup
5424 $qasked # The command
5425 ([\s\S]*?) # Description line(s)
5426 \n) # End of last description line
5427 (?!\s) # Next line not starting with
5436 # Not found; not a debugger command.
5438 print_help("B<$asked> is not a debugger command.\n");
5440 } ## end elsif ($line =~ /^(\S.*)$/)
5442 # 'h' - print the summary help.
5444 print_help($summary);
5448 =head3 C<cmd_i> - inheritance display
5450 Display the (nested) parentage of the module or object given.
5457 foreach my $isa ( split( /\s+/, $line ) ) {
5459 # The &-call is here to ascertain the mutability of @_.
5467 defined( ${"$_\::VERSION"} )
5468 ? ' ' . ${"$_\::VERSION"}
5470 } @{mro::get_linear_isa(ref($isa) || $isa)}
5476 =head3 C<cmd_l> - list lines (command)
5478 Most of the command is taken up with transforming all the different line
5479 specification syntaxes into 'start-stop'. After that is done, the command
5480 runs a loop over C<@dbline> for the specified range of lines. It handles
5481 the printing of each line and any markers (C<==E<gt>> for current line,
5482 C<b> for break on this line, C<a> for action on this line, C<:> for this
5485 We save the last line listed in the C<$start> global for further listing
5492 foreach my $v (@_) {
5502 foreach my $v (@_) {
5510 sub _minify_to_max {
5513 $$ref = _min($$ref, $max);
5518 sub _cmd_l_handle_var_name {
5519 my $var_name = shift;
5521 $evalarg = $var_name;
5523 my ($s) = DB::eval();
5525 # Ooops. Bad scalar.
5527 print {$OUT} "Error: $@\n";
5531 # Good scalar. If it's a reference, find what it points to.
5533 print {$OUT} "Interpreted as: $1 $s\n";
5536 # Call self recursively to really do the command.
5537 return _cmd_l_main( $s );
5540 sub _cmd_l_handle_subname {
5545 $subname =~ s/\'/::/;
5547 # Put it in this package unless it starts with ::.
5548 $subname = $package . "::" . $subname unless $subname =~ /::/;
5550 # Put it in CORE::GLOBAL if t doesn't start with :: and
5551 # it doesn't live in this package and it lives in CORE::GLOBAL.
5552 $subname = "CORE::GLOBAL::$s"
5553 if not defined &$subname
5555 and defined &{"CORE::GLOBAL::$s"};
5557 # Put leading '::' names into 'main::'.
5558 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
5560 # Get name:start-stop from find_sub, and break this up at
5562 my @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
5564 # Pull off start-stop.
5565 my $subrange = pop @pieces;
5567 # If the name contained colons, the split broke it up.
5568 # Put it back together.
5569 $file = join( ':', @pieces );
5571 # If we're not in that file, switch over to it.
5572 if ( $file ne $filename ) {
5573 if (! $slave_editor) {
5574 print {$OUT} "Switching to file '$file'.\n";
5577 # Switch debugger's magic structures.
5578 *dbline = $main::{ '_<' . $file };
5581 } ## end if ($file ne $filename)
5583 # Subrange is 'start-stop'. If this is less than a window full,
5584 # swap it to 'start+', which will list a window from the start point.
5586 if ( eval($subrange) < -$window ) {
5587 $subrange =~ s/-.*/+/;
5590 # Call self recursively to list the range.
5591 return _cmd_l_main( $subrange );
5592 } ## end if ($subrange)
5596 print {$OUT} "Subroutine $subname not found.\n";
5602 # Compute new range to list.
5603 $incr = $window - 1;
5606 return _cmd_l_main( $start . '-' . ( $start + $incr ) );
5610 my ($new_start, $new_incr) = @_;
5612 # Don't reset start for 'l +nnn'.
5613 $start = $new_start if $new_start;
5615 # Increment for list. Use window size if not specified.
5616 # (Allows 'l +' to work.)
5617 $incr = $new_incr || ($window - 1);
5619 # Create a line range we'll understand, and recurse to do it.
5620 return _cmd_l_main( $start . '-' . ( $start + $incr ) );
5623 sub _cmd_l_calc_initial_end_and_i {
5624 my ($spec, $start_match, $end_match) = @_;
5626 # Determine end point; use end of file if not specified.
5627 my $end = ( !defined $start_match ) ? $max :
5628 ( $end_match ? $end_match : $start_match );
5630 # Go on to the end, and then stop.
5631 _minify_to_max(\$end);
5633 # Determine start line.
5634 my $i = $start_match;
5648 my ($spec, $current_line, $start_match, $end_match) = @_;
5651 _cmd_l_calc_initial_end_and_i($spec, $start_match, $end_match);
5653 # If we're running under a slave editor, force it to show the lines.
5654 if ($slave_editor) {
5655 print {$OUT} "\032\032$filename:$i:0\n";
5658 # We're doing it ourselves. We want to show the line and special
5660 # - the current line in execution
5661 # - whether a line is breakable or not
5662 # - whether a line has a break or not
5663 # - whether a line has an action or not
5666 for ( ; $i <= $end ; $i++ ) {
5668 # Check for breakpoints and actions.
5669 my ( $stop, $action );
5671 ( $stop, $action ) = split( /\0/, $dbline{$i} );
5674 # ==> if this is the current line in execution,
5675 # : if it's breakable.
5677 ( $i == $current_line and $filename eq $filename_ini )
5679 : ( $dbline[$i] + 0 ? ':' : ' ' );
5681 # Add break and action indicators.
5682 $arrow .= 'b' if $stop;
5683 $arrow .= 'a' if $action;
5686 print {$OUT} "$i$arrow\t", $dbline[$i];
5688 # Move on to the next line. Drop out on an interrupt.
5693 } ## end for (; $i <= $end ; $i++)
5695 # Line the prompt up; print a newline if the last line listed
5696 # didn't have a newline.
5697 if ($dbline[ $i - 1 ] !~ /\n\z/) {
5700 } ## end else [ if ($slave_editor)
5702 # Save the point we last listed to in case another relative 'l'
5703 # command is desired. Don't let it run off the end.
5705 _minify_to_max(\$start);
5713 # If this is '-something', delete any spaces after the dash.
5714 $spec =~ s/\A-\s*\z/-/;
5716 # If the line is '$something', assume this is a scalar containing a
5718 # Set up for DB::eval() - evaluate in *user* context.
5719 if ( my ($var_name) = $spec =~ /\A(\$.*)/s ) {
5720 return _cmd_l_handle_var_name($var_name);
5722 # l name. Try to find a sub by that name.
5723 elsif ( ($subname) = $spec =~ /\A([\':A-Za-z_][\':\w]*(?:\[.*\])?)/s ) {
5724 return _cmd_l_handle_subname();
5727 elsif ( $spec !~ /\S/ ) {
5728 return _cmd_l_empty();
5730 # l [start]+number_of_lines
5731 elsif ( my ($new_start, $new_incr) = $spec =~ /\A(\d*)\+(\d*)\z/ ) {
5732 return _cmd_l_plus($new_start, $new_incr);
5734 # l start-stop or l start,stop
5735 elsif (my ($s, $e) = $spec =~ /^(?:(-?[\d\$\.]+)(?:[-,]([\d\$\.]+))?)?/ ) {
5736 return _cmd_l_range($spec, $line, $s, $e);
5743 my (undef, $line) = @_;
5745 return _cmd_l_main($line);
5748 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5750 To list breakpoints, the command has to look determine where all of them are
5751 first. It starts a C<%had_breakpoints>, which tells us what all files have
5752 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5753 magic source and breakpoint data structures) to the file, and then look
5754 through C<%dbline> for lines with breakpoints and/or actions, listing them
5755 out. We look through C<%postponed> not-yet-compiled subroutines that have
5756 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5757 that have breakpoints.
5759 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5763 sub _cmd_L_calc_arg {
5764 # If no argument, list everything. Pre-5.8.0 version always lists
5766 my $arg = shift || 'abw';
5767 if ($CommandSet ne '580')
5775 sub _cmd_L_calc_wanted_flags {
5776 my $arg = _cmd_L_calc_arg(shift);
5778 return (map { index($arg, $_) >= 0 ? 1 : 0 } qw(a b w));
5782 sub _cmd_L_handle_breakpoints {
5783 my ($handle_db_line) = @_;
5786 # Look in all the files with breakpoints...
5787 for my $file ( keys %had_breakpoints ) {
5789 # Temporary switch to this file.
5790 local *dbline = $main::{ '_<' . $file };
5792 # Set up to look through the whole file.
5794 my $was; # Flag: did we print something
5797 # For each line in the file ...
5798 for my $i (1 .. $max) {
5800 # We've got something on this line.
5801 if ( defined $dbline{$i} ) {
5803 # Print the header if we haven't.
5805 print {$OUT} "$file:\n";
5809 print {$OUT} " $i:\t", $dbline[$i];
5811 $handle_db_line->($dbline{$i});
5813 # Quit if the user hit interrupt.
5815 last BREAKPOINTS_SCAN;
5817 } ## end if (defined $dbline{$i...
5818 } ## end for my $i (1 .. $max)
5819 } ## end for my $file (keys %had_breakpoints)
5824 sub _cmd_L_handle_postponed_breakpoints {
5825 my ($handle_db_line) = @_;
5827 print {$OUT} "Postponed breakpoints in files:\n";
5830 for my $file ( keys %postponed_file ) {
5831 my $db = $postponed_file{$file};
5832 print {$OUT} " $file:\n";
5833 for my $line ( sort { $a <=> $b } keys %$db ) {
5834 print {$OUT} " $line:\n";
5836 $handle_db_line->($db->{$line});
5839 last POSTPONED_SCANS;
5843 last POSTPONED_SCANS;
5854 my ($action_wanted, $break_wanted, $watch_wanted) =
5855 _cmd_L_calc_wanted_flags(shift);
5857 my $handle_db_line = sub {
5860 my ( $stop, $action ) = split( /\0/, $l );
5862 if ($stop and $break_wanted) {
5863 print {$OUT} " break if (", $stop, ")\n"
5866 if ($action && $action_wanted) {
5867 print {$OUT} " action: ", $action, "\n"
5873 # Breaks and actions are found together, so we look in the same place
5875 if ( $break_wanted or $action_wanted ) {
5876 _cmd_L_handle_breakpoints($handle_db_line);
5879 # Look for breaks in not-yet-compiled subs:
5880 if ( %postponed and $break_wanted ) {
5881 print {$OUT} "Postponed breakpoints in subroutines:\n";
5884 for $subname ( keys %postponed ) {
5885 print {$OUT} " $subname\t$postponed{$subname}\n";
5890 } ## end if (%postponed and $break_wanted)
5892 # Find files that have not-yet-loaded breaks:
5893 my @have = map { # Combined keys
5894 keys %{ $postponed_file{$_} }
5895 } keys %postponed_file;
5897 # If there are any, list them.
5898 if ( @have and ( $break_wanted or $action_wanted ) ) {
5899 _cmd_L_handle_postponed_breakpoints($handle_db_line);
5900 } ## end if (@have and ($break_wanted...
5902 if ( %break_on_load and $break_wanted ) {
5903 print {$OUT} "Breakpoints on load:\n";
5904 BREAK_ON_LOAD: for my $filename ( keys %break_on_load ) {
5905 print {$OUT} " $filename\n";
5906 last BREAK_ON_LOAD if $signal;
5908 } ## end if (%break_on_load and...
5910 if ($watch_wanted and ( $trace & 2 )) {
5911 print {$OUT} "Watch-expressions:\n" if @to_watch;
5912 TO_WATCH: for my $expr (@to_watch) {
5913 print {$OUT} " $expr\n";
5914 last TO_WATCH if $signal;
5921 =head3 C<cmd_M> - list modules (command)
5923 Just call C<list_modules>.
5933 =head3 C<cmd_o> - options (command)
5935 If this is just C<o> by itself, we list the current settings via
5936 C<dump_option>. If there's a nonblank value following it, we pass that on to
5937 C<parse_options> for processing.
5943 my $opt = shift || ''; # opt[=val]
5945 # Nonblank. Try to parse and process.
5946 if ( $opt =~ /^(\S.*)/ ) {
5950 # Blank. List the current option settings.
5958 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5960 Advises the user that the O command has been renamed.
5965 print $OUT "The old O command is now the o command.\n"; # hint
5966 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5967 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5970 =head3 C<cmd_v> - view window (command)
5972 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5973 move back a few lines to list the selected line in context. Uses C<cmd_l>
5974 to do the actual listing after figuring out the range of line to request.
5978 use vars qw($preview);
5984 # Extract the line to list around. (Astute readers will have noted that
5985 # this pattern will match whether or not a numeric line is specified,
5986 # which means that we'll always enter this loop (though a non-numeric
5987 # argument results in no action at all)).
5988 if ( $line =~ /^(\d*)$/ ) {
5990 # Total number of lines to list (a windowful).
5991 $incr = $window - 1;
5993 # Set the start to the argument given (if there was one).
5996 # Back up by the context amount.
5999 # Put together a linespec that cmd_l will like.
6000 $line = $start . '-' . ( $start + $incr );
6003 cmd_l( 'l', $line );
6004 } ## end if ($line =~ /^(\d*)$/)
6007 =head3 C<cmd_w> - add a watch expression (command)
6009 The 5.8 version of this command adds a watch expression if one is specified;
6010 it does nothing if entered with no operands.
6012 We extract the expression, save it, evaluate it in the user's context, and
6013 save the value. We'll re-evaluate it each time the debugger passes a line,
6014 and will stop (see the code at the top of the command loop) if the value
6015 of any of the expressions changes.
6019 sub _add_watch_expr {
6023 push @to_watch, $expr;
6025 # Parameterize DB::eval and call it to get the expression's value
6026 # in the user's context. This version can handle expressions which
6027 # return a list value.
6029 # The &-call is here to ascertain the mutability of @_.
6030 my ($val) = join( ' ', &DB::eval);
6031 $val = ( defined $val ) ? "'$val'" : 'undef';
6033 # Save the current value of the expression.
6034 push @old_watch, $val;
6036 # We are now watching expressions.
6045 # Null expression if no arguments.
6046 my $expr = shift || '';
6048 # If expression is not null ...
6049 if ( $expr =~ /\A\S/ ) {
6050 _add_watch_expr($expr);
6051 } ## end if ($expr =~ /^(\S.*)/)
6053 # You have to give one to get one.
6055 print $OUT "Adding a watch-expression requires an expression\n"; # hint
6061 =head3 C<cmd_W> - delete watch expressions (command)
6063 This command accepts either a watch expression to be removed from the list
6064 of watch expressions, or C<*> to delete them all.
6066 If C<*> is specified, we simply empty the watch expression list and the
6067 watch expression value list. We also turn off the bit that says we've got
6070 If an expression (or partial expression) is specified, we pattern-match
6071 through the expressions and remove the ones that match. We also discard
6072 the corresponding values. If no watch expressions are left, we turn off
6073 the I<watching expressions> bit.
6079 my $expr = shift || '';
6082 if ( $expr eq '*' ) {
6087 print $OUT "Deleting all watch expressions ...\n";
6090 @to_watch = @old_watch = ();
6093 # Delete one of them.
6094 elsif ( $expr =~ /^(\S.*)/ ) {
6096 # Where we are in the list.
6099 # For each expression ...
6100 foreach (@to_watch) {
6101 my $val = $to_watch[$i_cnt];
6103 # Does this one match the command argument?
6104 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
6105 # Yes. Turn it off, and its value too.
6106 splice( @to_watch, $i_cnt, 1 );
6107 splice( @old_watch, $i_cnt, 1 );
6110 } ## end foreach (@to_watch)
6112 # We don't bother to turn watching off because
6113 # a) we don't want to stop calling watchfunction() if it exists
6114 # b) foreach over a null list doesn't do anything anyway
6116 } ## end elsif ($expr =~ /^(\S.*)/)
6118 # No command arguments entered.
6121 "Deleting a watch-expression requires an expression, or '*' for all\n"
6126 ### END of the API section
6128 =head1 SUPPORT ROUTINES
6130 These are general support routines that are used in a number of places
6131 throughout the debugger.
6135 save() saves the user's versions of globals that would mess us up in C<@saved>,
6136 and installs the versions we like better.
6142 # Save eval failure, command failure, extended OS error, output field
6143 # separator, input record separator, output record separator and
6144 # the warning setting.
6145 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
6147 $, = ""; # output field separator is null string
6148 $/ = "\n"; # input record separator is newline
6149 $\ = ""; # output record separator is null string
6150 $^W = 0; # warnings are off
6153 =head2 C<print_lineinfo> - show where we are now
6155 print_lineinfo prints whatever it is that it is handed; it prints it to the
6156 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
6157 us to feed line information to a slave editor without messing up the
6162 sub print_lineinfo {
6164 # Make the terminal sensible if we're not the primary debugger.
6165 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
6168 # $LINEINFO may be undef if $noTTY is set or some other issue.
6171 print {$LINEINFO} @_;
6173 } ## end sub print_lineinfo
6175 =head2 C<postponed_sub>
6177 Handles setting postponed breakpoints in subroutines once they're compiled.
6178 For breakpoints, we use C<DB::find_sub> to locate the source file and line
6179 range for the subroutine, then mark the file as having a breakpoint,
6180 temporarily switch the C<*dbline> glob over to the source file, and then
6181 search the given range of lines to find a breakable line. If we find one,
6182 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
6186 # The following takes its argument via $evalarg to preserve current @_
6190 # Get the subroutine name.
6191 my $subname = shift;
6193 # If this is a 'break +<n> if <condition>' ...
6194 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
6196 # If there's no offset, use '+0'.
6197 my $offset = $1 || 0;
6199 # find_sub's value is 'fullpath-filename:start-stop'. It's
6200 # possible that the filename might have colons in it too.
6201 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
6204 # We got the start line. Add the offset '+<n>' from
6205 # $postponed{subname}.
6208 # Switch to the file this sub is in, temporarily.
6209 local *dbline = $main::{ '_<' . $file };
6211 # No warnings, please.
6212 local $^W = 0; # != 0 is magical below
6214 # This file's got a breakpoint in it.
6215 $had_breakpoints{$file} |= 1;
6217 # Last line in file.
6220 # Search forward until we hit a breakable line or get to
6221 # the end of the file.
6222 ++$i until $dbline[$i] != 0 or $i >= $max;
6224 # Copy the breakpoint in and delete it from %postponed.
6225 $dbline{$i} = delete $postponed{$subname};
6228 # find_sub didn't find the sub.
6231 print $OUT "Subroutine $subname not found.\n";
6234 } ## end if ($postponed{$subname...
6235 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
6237 #print $OUT "In postponed_sub for '$subname'.\n";
6238 } ## end sub postponed_sub
6242 Called after each required file is compiled, but before it is executed;
6243 also called if the name of a just-compiled subroutine is a key of
6244 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
6245 etc.) into the just-compiled code.
6247 If this is a C<require>'d file, the incoming parameter is the glob
6248 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
6250 If it's a subroutine, the incoming parameter is the subroutine name.
6256 # If there's a break, process it.
6257 if ($ImmediateStop) {
6259 # Right, we've stopped. Turn it off.
6262 # Enter the command loop when DB::DB gets called.
6266 # If this is a subroutine, let postponed_sub() deal with it.
6267 if (ref(\$_[0]) ne 'GLOB') {
6268 return postponed_sub(@_);
6271 # Not a subroutine. Deal with the file.
6272 local *dbline = shift;
6273 my $filename = $dbline;
6274 $filename =~ s/^_<//;
6276 $signal = 1, print $OUT "'$filename' loaded...\n"
6277 if $break_on_load{$filename};
6278 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
6280 # Do we have any breakpoints to put in this file?
6281 return unless $postponed_file{$filename};
6283 # Yes. Mark this file as having breakpoints.
6284 $had_breakpoints{$filename} |= 1;
6286 # "Cannot be done: insufficient magic" - we can't just put the
6287 # breakpoints saved in %postponed_file into %dbline by assigning
6288 # the whole hash; we have to do it one item at a time for the
6289 # breakpoints to be set properly.
6290 #%dbline = %{$postponed_file{$filename}};
6292 # Set the breakpoints, one at a time.
6295 for $key ( keys %{ $postponed_file{$filename} } ) {
6297 # Stash the saved breakpoint into the current file's magic line array.
6298 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
6301 # This file's been compiled; discard the stored breakpoints.
6302 delete $postponed_file{$filename};
6304 } ## end sub postponed
6308 C<dumpit> is the debugger's wrapper around dumpvar.pl.
6310 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
6311 a reference to a variable (the thing to be dumped) as its input.
6313 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
6314 the currently-selected filehandle, thank you very much). The current
6315 values of the package globals C<$single> and C<$trace> are backed up in
6316 lexicals, and they are turned off (this keeps the debugger from trying
6317 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
6318 preserve its current value and it is set to zero to prevent entry/exit
6319 messages from printing, and C<$doret> is localized as well and set to -2 to
6320 prevent return values from being shown.
6322 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
6323 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
6324 installed version in C<@INC>, yours will be used instead. Possible security
6327 It then checks to see if the subroutine C<main::dumpValue> is now defined
6328 it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
6329 localizes the globals necessary for things to be sane when C<main::dumpValue()>
6330 is called, and picks up the variable to be dumped from the parameter list.
6332 It checks the package global C<%options> to see if there's a C<dumpDepth>
6333 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
6334 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
6335 structure: -1 means dump everything.
6337 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
6340 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
6341 and we then return to the caller.
6347 # Save the current output filehandle and switch to the one
6348 # passed in as the first parameter.
6349 my $savout = select(shift);
6351 # Save current settings of $single and $trace, and then turn them off.
6352 my $osingle = $single;
6353 my $otrace = $trace;
6354 $single = $trace = 0;
6356 # XXX Okay, what do $frame and $doret do, again?
6360 # Load dumpvar.pl unless we've already got the sub we need from it.
6361 unless ( defined &main::dumpValue ) {
6362 do 'dumpvar.pl' or die $@;
6365 # If the load succeeded (or we already had dumpvalue()), go ahead
6367 if ( defined &main::dumpValue ) {
6372 my $maxdepth = shift || $option{dumpDepth};
6373 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
6374 main::dumpValue( $v, $maxdepth );
6375 } ## end if (defined &main::dumpValue)
6377 # Oops, couldn't load dumpvar.pl.
6380 print $OUT "dumpvar.pl not available.\n";
6383 # Reset $single and $trace to their old values.
6387 # Restore the old filehandle.
6391 =head2 C<print_trace>
6393 C<print_trace>'s job is to print a stack trace. It does this via the
6394 C<dump_trace> routine, which actually does all the ferreting-out of the
6395 stack trace data. C<print_trace> takes care of formatting it nicely and
6396 printing it to the proper filehandle.
6404 The filehandle to print to.
6408 How many frames to skip before starting trace.
6412 How many frames to print.
6416 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
6420 The original comment below seems to be noting that the traceback may not be
6421 correct if this routine is called in a tied method.
6425 # Tied method do not create a context, so may get wrong message:
6431 # If this is going to a slave editor, but we're not the primary
6432 # debugger, reset it first.
6434 if $fh eq $LINEINFO # slave editor
6435 and $LINEINFO eq $OUT # normal output
6436 and $term_pid != $$; # not the primary
6438 # Collect the actual trace information to be formatted.
6439 # This is an array of hashes of subroutine call info.
6440 my @sub = dump_trace( $_[0] + 1, $_[1] );
6442 # Grab the "short report" flag from @_.
6443 my $short = $_[2]; # Print short report, next one for sub name
6445 # Run through the traceback info, format it, and print it.
6447 for my $i (0 .. $#sub) {
6449 # Drop out if the user has lost interest and hit control-C.
6452 # Set the separator so arrays print nice.
6455 # Grab and stringify the arguments if they are there.
6457 defined $sub[$i]{args}
6458 ? "(@{ $sub[$i]{args} })"
6461 # Shorten them up if $maxtrace says they're too long.
6462 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
6463 if length $args > $maxtrace;
6465 # Get the file name.
6466 my $file = $sub[$i]{file};
6468 # Put in a filename header if short is off.
6469 $file = $file eq '-e' ? $file : "file '$file'" unless $short;
6471 # Get the actual sub's name, and shorten to $maxtrace's requirement.
6472 $s = $sub[$i]{'sub'};
6473 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
6475 # Short report uses trimmed file and sub names.
6477 my $sub = @_ >= 4 ? $_[3] : $s;
6478 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
6479 } ## end if ($short)
6481 # Non-short report includes full names.
6483 print $fh "$sub[$i]{context} = $s$args"
6484 . " called from $file"
6485 . " line $sub[$i]{line}\n";
6487 } ## end for my $i (0 .. $#sub)
6488 } ## end sub print_trace
6490 =head2 dump_trace(skip[,count])
6492 Actually collect the traceback information available via C<caller()>. It does
6493 some filtering and cleanup of the data, but mostly it just collects it to
6494 make C<print_trace()>'s job easier.
6496 C<skip> defines the number of stack frames to be skipped, working backwards
6497 from the most current. C<count> determines the total number of frames to
6498 be returned; all of them (well, the first 10^9) are returned if C<count>
6501 This routine returns a list of hashes, from most-recent to least-recent
6502 stack frame. Each has the following keys and values:
6506 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
6508 =item * C<sub> - subroutine name, or C<eval> information
6510 =item * C<args> - undef, or a reference to an array of arguments
6512 =item * C<file> - the file in which this item was defined (if any)
6514 =item * C<line> - the line on which it was defined
6520 sub _dump_trace_calc_saved_single_arg
6522 my ($nothard, $arg) = @_;
6525 if ( not defined $arg ) { # undefined parameter
6529 elsif ( $nothard and tied $arg ) { # tied parameter
6532 elsif ( $nothard and $type = ref $arg ) { # reference
6533 return "ref($type)";
6535 else { # can be stringified
6537 "$arg"; # Safe to stringify now - should not call f().
6539 # Backslash any single-quotes or backslashes.
6542 # Single-quote it unless it's a number or a colon-separated
6545 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
6547 # Turn high-bit characters into meta-whatever, and controls into like
6549 require 'meta_notation.pm';
6550 $_ = _meta_notation($_) if /[[:^print:]]/a;
6556 sub _dump_trace_calc_save_args {
6560 map { _dump_trace_calc_saved_single_arg($nothard, $_) } @args
6566 # How many levels to skip.
6569 # How many levels to show. (1e9 is a cheap way of saying "all of them";
6570 # it's unlikely that we'll have more than a billion stack frames. If you
6571 # do, you've got an awfully big machine...)
6572 my $count = shift || 1e9;
6574 # We increment skip because caller(1) is the first level *back* from
6575 # the current one. Add $skip to the count of frames so we have a
6576 # simple stop criterion, counting from $skip to $count+$skip.
6580 # These variables are used to capture output from caller();
6581 my ( $p, $file, $line, $sub, $h, $context );
6583 my ( $e, $r, @sub, $args );
6585 # XXX Okay... why'd we do that?
6586 my $nothard = not $frame & 8;
6589 # Do not want to trace this.
6590 my $otrace = $trace;
6593 # Start out at the skip count.
6594 # If we haven't reached the number of frames requested, and caller() is
6595 # still returning something, stay in the loop. (If we pass the requested
6596 # number of stack frames, or we run out - caller() returns nothing - we
6598 # Up the stack frame index to go back one more level each time.
6602 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
6607 # Go through the arguments and save them for later.
6608 my $save_args = _dump_trace_calc_save_args($nothard);
6610 # If context is true, this is array (@)context.
6611 # If context is false, this is scalar ($) context.
6612 # If neither, context isn't defined. (This is apparently a 'can't
6614 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
6616 # if the sub has args ($h true), make an anonymous array of the
6618 $args = $h ? $save_args : undef;
6620 # remove trailing newline-whitespace-semicolon-end of line sequence
6621 # from the eval text, if any.
6622 $e =~ s/\n\s*\;\s*\Z// if $e;
6624 # Escape backslashed single-quotes again if necessary.
6625 $e =~ s/([\\\'])/\\$1/g if $e;
6627 # if the require flag is true, the eval text is from a require.
6629 $sub = "require '$e'";
6632 # if it's false, the eval text is really from an eval.
6633 elsif ( defined $r ) {
6637 # If the sub is '(eval)', this is a block eval, meaning we don't
6638 # know what the eval'ed text actually was.
6639 elsif ( $sub eq '(eval)' ) {
6640 $sub = "eval {...}";
6643 # Stick the collected information into @sub as an anonymous hash.
6647 context => $context,
6655 # Stop processing frames if the user hit control-C.
6657 } ## end for ($i = $skip ; $i < ...
6659 # Restore the trace value again.
6662 } ## end sub dump_trace
6666 C<action()> takes input provided as the argument to an add-action command,
6667 either pre- or post-, and makes sure it's a complete command. It doesn't do
6668 any fancy parsing; it just keeps reading input until it gets a string
6669 without a trailing backslash.
6676 while ( $action =~ s/\\$// ) {
6678 # We have a backslash on the end. Read more.
6680 } ## end while ($action =~ s/\\$//)
6682 # Return the assembled action.
6688 This routine mostly just packages up a regular expression to be used
6689 to check that the thing it's being matched against has properly-matched
6692 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
6693 speeds things up by only creating the qr//'ed expression once; if it's
6694 already defined, we don't try to define it again. A speed hack.
6698 use vars qw($balanced_brace_re);
6702 # I hate using globals!
6703 $balanced_brace_re ||= qr{
6706 (?> [^{}] + ) # Non-parens without backtracking
6708 (??{ $balanced_brace_re }) # Group with matching parens
6712 return $_[0] !~ m/$balanced_brace_re/;
6713 } ## end sub unbalanced
6717 C<gets()> is a primitive (very primitive) routine to read continuations.
6718 It was devised for reading continuations for actions.
6719 it just reads more input with C<readline()> and returns it.
6724 return DB::readline("cont: ");
6727 =head2 C<_db_system()> - handle calls to<system()> without messing up the debugger
6729 The C<system()> function assumes that it can just go ahead and use STDIN and
6730 STDOUT, but under the debugger, we want it to use the debugger's input and
6733 C<_db_system()> socks away the program's STDIN and STDOUT, and then substitutes
6734 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
6735 and then puts everything back again.
6741 # We save, change, then restore STDIN and STDOUT to avoid fork() since
6742 # some non-Unix systems can do system() but have problems with fork().
6743 open( SAVEIN, "<&STDIN" ) || _db_warn("Can't save STDIN");
6744 open( SAVEOUT, ">&STDOUT" ) || _db_warn("Can't save STDOUT");
6745 open( STDIN, "<&IN" ) || _db_warn("Can't redirect STDIN");
6746 open( STDOUT, ">&OUT" ) || _db_warn("Can't redirect STDOUT");
6748 # XXX: using csh or tcsh destroys sigint retvals!
6750 open( STDIN, "<&SAVEIN" ) || _db_warn("Can't restore STDIN");
6751 open( STDOUT, ">&SAVEOUT" ) || _db_warn("Can't restore STDOUT");
6755 # most of the $? crud was coping with broken cshisms
6757 _db_warn( "(Command exited ", ( $? >> 8 ), ")\n" );
6761 "(Command died of SIG#",
6763 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6772 *system = \&_db_system;
6774 =head1 TTY MANAGEMENT
6776 The subs here do some of the terminal management for multiple debuggers.
6780 Top-level function called when we want to set up a new terminal for use
6783 If the C<noTTY> debugger option was set, we'll either use the terminal
6784 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6785 to find one. If we're a forked debugger, we call C<resetterm> to try to
6786 get a whole new terminal if we can.
6788 In either case, we set up the terminal next. If the C<ReadLine> option was
6789 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6790 the appropriate attributes. We then
6794 use vars qw($ornaments);
6795 use vars qw($rl_attribs);
6799 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6802 require Term::ReadLine;
6804 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6807 my ( $i, $o ) = split $tty, /,/;
6808 $o = $i unless defined $o;
6809 open( IN, "<$i" ) or die "Cannot open TTY '$i' for read: $!";
6810 open( OUT, ">$o" ) or die "Cannot open TTY '$o' for write: $!";
6816 # We don't have a TTY - try to find one via Term::Rendezvous.
6818 require Term::Rendezvous;
6820 # See if we have anything to pass to Term::Rendezvous.
6821 # Use $HOME/.perldbtty$$ if not.
6822 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6824 # Rendezvous and get the filehandles.
6825 my $term_rv = Term::Rendezvous->new( $rv );
6827 $OUT = $term_rv->OUT;
6828 } ## end else [ if ($tty)
6829 } ## end if ($notty)
6831 # We're a daughter debugger. Try to fork off another TTY.
6832 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6836 # If we shouldn't use Term::ReadLine, don't.
6838 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6841 # We're using Term::ReadLine. Get all the attributes for this terminal.
6843 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6845 $rl_attribs = $term->Attribs;
6846 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6847 if defined $rl_attribs->{basic_word_break_characters}
6848 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6849 $rl_attribs->{special_prefixes} = '$@&%';
6850 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6851 $rl_attribs->{completion_function} = \&db_complete;
6852 } ## end else [ if (!$rl)
6854 # Set up the LINEINFO filehandle.
6855 $LINEINFO = $OUT unless defined $LINEINFO;
6856 $lineinfo = $console unless defined $lineinfo;
6862 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6863 $term->SetHistory(@hist);
6866 # XXX Ornaments are turned on unconditionally, which is not
6867 # always a good thing.
6868 ornaments($ornaments) if defined $ornaments;
6870 } ## end sub setterm
6873 $histfile //= option_val("HistFile", undef);
6874 return unless defined $histfile;
6875 open my $fh, "<", $histfile or return;
6886 return unless defined $histfile;
6887 eval { require File::Path } or return;
6888 eval { require File::Basename } or return;
6889 File::Path::mkpath(File::Basename::dirname($histfile));
6890 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6891 $histsize //= option_val("HistSize",100);
6892 my @copy = grep { $_ ne '?' } @hist;
6893 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6894 for ($start .. $#copy) {
6895 print $fh "$copy[$_]\n";
6897 close $fh or die "Could not write '$histfile': $!";
6900 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6902 When the process being debugged forks, or the process invokes a command
6903 via C<system()> which starts a new debugger, we need to be able to get a new
6904 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6905 fight over the terminal, and you can never quite be sure who's going to get the
6906 input you're typing.
6908 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6909 is tasked with doing all the necessary operating system mojo to get a new
6910 TTY (and probably another window) and to direct the new debugger to read and
6913 The debugger provides C<get_fork_TTY> functions which work for TCP
6914 socket servers, X11, OS/2, and Mac OS X. Other systems are not
6915 supported. You are encouraged to write C<get_fork_TTY> functions which
6916 work for I<your> platform and contribute them.
6918 =head3 C<socket_get_fork_TTY>
6922 sub connect_remoteport {
6925 my $socket = IO::Socket::INET->new(
6927 PeerAddr => $remoteport,
6931 die "Unable to connect to remote host: $remoteport\n";
6936 sub socket_get_fork_TTY {
6937 $tty = $LINEINFO = $IN = $OUT = connect_remoteport();
6939 # Do I need to worry about setting $term?
6941 reset_IN_OUT( $IN, $OUT );
6945 =head3 C<xterm_get_fork_TTY>
6947 This function provides the C<get_fork_TTY> function for X11. If a
6948 program running under the debugger forks, a new <xterm> window is opened and
6949 the subsidiary debugger is directed there.
6951 The C<open()> call is of particular note here. We have the new C<xterm>
6952 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6953 command (which prints the device name of the TTY we'll want to use for input
6954 and output to STDOUT, then C<sleep> for a very long time, routing this output
6955 to file number 3. This way we can simply read from the <XT> filehandle (which
6956 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6958 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6963 sub xterm_get_fork_TTY {
6964 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6966 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6969 # Get the output from 'tty' and clean it up a little.
6973 $pidprompt = ''; # Shown anyway in titlebar
6975 # We need $term defined or we can not switch to the newly created xterm
6976 if ($tty ne '' && !defined $term) {
6977 require Term::ReadLine;
6979 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6982 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6985 # There's our new TTY.
6987 } ## end sub xterm_get_fork_TTY
6989 =head3 C<os2_get_fork_TTY>
6991 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6995 # This example function resets $IN, $OUT itself
6997 sub os2_get_fork_TTY { # A simplification of the following (and works without):
6999 ( my $name = $0 ) =~ s,^.*[/\\],,s;
7000 my %opt = ( title => "Daughter Perl debugger $pids $name",
7001 ($rl ? (read_by_key => 1) : ()) );
7002 require OS2::Process;
7003 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
7005 $pidprompt = ''; # Shown anyway in titlebar
7006 reset_IN_OUT($in, $out);
7008 return ''; # Indicate that reset_IN_OUT is called
7009 } ## end sub os2_get_fork_TTY
7011 =head3 C<macosx_get_fork_TTY>
7013 The Mac OS X version uses AppleScript to tell Terminal.app to create
7018 # Notes about Terminal.app's AppleScript support,
7019 # (aka things that might break in future OS versions).
7021 # The "do script" command doesn't return a reference to the new window
7022 # it creates, but since it appears frontmost and windows are enumerated
7023 # front to back, we can use "first window" === "window 1".
7025 # Since "do script" is implemented by supplying the argument (plus a
7026 # return character) as terminal input, there's a potential race condition
7027 # where the debugger could beat the shell to reading the command.
7028 # To prevent this, we wait for the screen to clear before proceeding.
7031 # There's no direct accessor for the tty device name, so we fiddle
7032 # with the window title options until it says what we want.
7035 # There _is_ a direct accessor for the tty device name, _and_ there's
7036 # a new possible component of the window title (the name of the settings
7037 # set). A separate version is needed.
7039 my @script_versions=
7041 ([237, <<'__LEOPARD__'],
7042 tell application "Terminal"
7043 do script "clear;exec sleep 100000"
7044 tell first tab of first window
7046 set custom title to "forked perl debugger"
7047 set title displays custom title to true
7048 repeat while (length of first paragraph of (get contents)) > 0
7056 [100, <<'__JAGUAR_TIGER__'],
7057 tell application "Terminal"
7058 do script "clear;exec sleep 100000"
7060 set title displays shell path to false
7061 set title displays window size to false
7062 set title displays file name to false
7063 set title displays device name to true
7064 set title displays custom title to true
7065 set custom title to ""
7066 copy "/dev/" & name to thetty
7067 set custom title to "forked perl debugger"
7068 repeat while (length of first paragraph of (get contents)) > 0
7078 sub macosx_get_fork_TTY
7080 my($version,$script,$pipe,$tty);
7082 return unless $version=$ENV{TERM_PROGRAM_VERSION};
7083 foreach my $entry (@script_versions) {
7084 if ($version>=$entry->[0]) {
7085 $script=$entry->[1];
7089 return unless defined($script);
7090 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
7091 $tty=readline($pipe);
7093 return unless defined($tty) && $tty =~ m(^/dev/);
7098 =head3 C<tmux_get_fork_TTY>
7100 Creates a split window for subprocesses when a process running under the
7101 perl debugger in Tmux forks.
7105 sub tmux_get_fork_TTY {
7106 return unless $ENV{TMUX};
7110 my $status = open $pipe, '-|', 'tmux', 'split-window',
7111 '-P', '-F', '#{pane_tty}', 'sleep 100000';
7123 if ( !defined $term ) {
7124 require Term::ReadLine;
7126 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
7129 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
7137 =head2 C<create_IN_OUT($flags)>
7139 Create a new pair of filehandles, pointing to a new TTY. If impossible,
7140 try to diagnose why.
7146 =item * 1 - Don't know how to create a new TTY.
7148 =item * 2 - Debugger has forked, but we can't get a new TTY.
7150 =item * 4 - standard debugger startup is happening.
7156 use vars qw($fork_TTY);
7158 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
7160 # If we know how to get a new TTY, do it! $in will have
7161 # the TTY name if get_fork_TTY works.
7162 my $in = get_fork_TTY(@_) if defined &get_fork_TTY;
7164 # It used to be that
7165 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
7167 if ( not defined $in ) {
7170 # We don't know how.
7171 print_help(<<EOP) if $why == 1;
7172 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
7176 print_help(<<EOP) if $why == 2;
7177 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
7178 This may be an asynchronous session, so the parent debugger may be active.
7181 # Note that both debuggers are fighting over the same input.
7182 print_help(<<EOP) if $why != 4;
7183 Since two debuggers fight for the same TTY, input is severely entangled.
7187 I know how to switch the output to a different window in xterms, OS/2
7188 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
7189 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
7190 B<DB::get_fork_TTY()> returning this.
7192 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
7193 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
7196 } ## end if (not defined $in)
7197 elsif ( $in ne '' ) {
7201 $console = ''; # Indicate no need to open-from-the-console
7204 } ## end sub create_IN_OUT
7208 Handles rejiggering the prompt when we've forked off a new debugger.
7210 If the new debugger happened because of a C<system()> that invoked a
7211 program under the debugger, the arrow between the old pid and the new
7212 in the prompt has I<two> dashes instead of one.
7214 We take the current list of pids and add this one to the end. If there
7215 isn't any list yet, we make one up out of the initial pid associated with
7216 the terminal and our new pid, sticking an arrow (either one-dashed or
7217 two dashed) in between them.
7219 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
7220 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
7225 sub resetterm { # We forked, so we need a different TTY
7227 # Needs to be passed to create_IN_OUT() as well.
7230 # resetterm(2): got in here because of a system() starting a debugger.
7231 # resetterm(1): just forked.
7232 my $systemed = $in > 1 ? '-' : '';
7234 # If there's already a list of pids, add this to the end.
7236 $pids =~ s/\]/$systemed->$$]/;
7239 # No pid list. Time to make one.
7241 $pids = "[$term_pid->$$]";
7244 # The prompt we're going to be using for this debugger.
7247 # We now 0wnz this terminal.
7250 # Just return if we're not supposed to try to create a new TTY.
7251 return unless $CreateTTY & $in;
7253 # Try to create a new IN/OUT pair.
7255 } ## end sub resetterm
7259 First, we handle stuff in the typeahead buffer. If there is any, we shift off
7260 the next line, print a message saying we got it, add it to the terminal
7261 history (if possible), and return it.
7263 If there's nothing in the typeahead buffer, check the command filehandle stack.
7264 If there are any filehandles there, read from the last one, and return the line
7265 if we got one. If not, we pop the filehandle off and close it, and try the
7266 next one up the stack.
7268 If we've emptied the filehandle stack, we check to see if we've got a socket
7269 open, and we read that and return it if we do. If we don't, we just call the
7270 core C<readline()> and return its value.
7276 # Localize to prevent it from being smashed in the program being debugged.
7279 # If there are stacked filehandles to read from ...
7280 # (Handle it before the typeahead, because we may call source/etc. from
7284 # Read from the last one in the stack.
7285 my $line = CORE::readline( $cmdfhs[-1] );
7287 # If we got a line ...
7289 ? ( print $OUT ">> $line" and return $line ) # Echo and return
7290 : close pop @cmdfhs; # Pop and close
7291 } ## end while (@cmdfhs)
7293 # Pull a line out of the typeahead if there's stuff there.
7296 # How many lines left.
7297 my $left = @typeahead;
7299 # Get the next line.
7300 my $got = shift @typeahead;
7302 # Print a message saying we got input from the typeahead.
7304 print $OUT "auto(-$left)", shift, $got, "\n";
7306 # Add it to the terminal history (if possible).
7307 $term->AddHistory($got)
7309 and defined $term->Features->{addHistory};
7311 } ## end if (@typeahead)
7313 # We really need to read some input. Turn off entry/exit trace and
7314 # return value printing.
7318 # Nothing on the filehandle stack. Socket?
7319 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
7321 # Send anything we have to send.
7322 $OUT->write( join( '', @_ ) );
7324 # Receive anything there is to receive.
7329 while ($first_time or (length($buf) && ($stuff .= $buf) !~ /\n/))
7332 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
7333 # XXX Don't know. You tell me.
7338 } ## end if (ref $OUT and UNIVERSAL::isa...
7340 # No socket. Just read from the terminal.
7342 return $term->readline(@_);
7344 } ## end sub readline
7346 =head1 OPTIONS SUPPORT ROUTINES
7348 These routines handle listing and setting option values.
7350 =head2 C<dump_option> - list the current value of an option setting
7352 This routine uses C<option_val> to look up the value for an option.
7353 It cleans up escaped single-quotes and then displays the option and
7359 my ( $opt, $val ) = @_;
7360 $val = option_val( $opt, 'N/A' );
7361 $val =~ s/([\\\'])/\\$1/g;
7362 printf $OUT "%20s = '%s'\n", $opt, $val;
7363 } ## end sub dump_option
7365 sub options2remember {
7366 foreach my $k (@RememberOnROptions) {
7367 $option{$k} = option_val( $k, 'N/A' );
7372 =head2 C<option_val> - find the current value of an option
7374 This can't just be a simple hash lookup because of the indirect way that
7375 the option values are stored. Some are retrieved by calling a subroutine,
7376 some are just variables.
7378 You must supply a default value to be used in case the option isn't set.
7383 my ( $opt, $default ) = @_;
7386 # Does this option exist, and is it a variable?
7387 # If so, retrieve the value via the value in %optionVars.
7388 if ( defined $optionVars{$opt}
7389 and defined ${ $optionVars{$opt} } )
7391 $val = ${ $optionVars{$opt} };
7394 # Does this option exist, and it's a subroutine?
7395 # If so, call the subroutine via the ref in %optionAction
7396 # and capture the value.
7397 elsif ( defined $optionAction{$opt}
7398 and defined &{ $optionAction{$opt} } )
7400 $val = &{ $optionAction{$opt} }();
7403 # If there's an action or variable for the supplied option,
7404 # but no value was set, use the default.
7405 elsif (defined $optionAction{$opt} and not defined $option{$opt}
7406 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
7411 # Otherwise, do the simple hash lookup.
7413 $val = $option{$opt};
7416 # If the value isn't defined, use the default.
7417 # Then return whatever the value is.
7418 $val = $default unless defined $val;
7420 } ## end sub option_val
7422 =head2 C<parse_options>
7424 Handles the parsing and execution of option setting/displaying commands.
7426 An option entered by itself is assumed to be I<set me to 1> (the default value)
7427 if the option is a boolean one. If not, the user is prompted to enter a valid
7428 value or to query the current value (via C<option? >).
7430 If C<option=value> is entered, we try to extract a quoted string from the
7431 value (if it is quoted). If it's not, we just use the whole value as-is.
7433 We load any modules required to service this option, and then we set it: if
7434 it just gets stuck in a variable, we do that; if there's a subroutine to
7435 handle setting the option, we call that.
7437 Finally, if we're running in interactive mode, we display the effect of the
7438 user's command back to the terminal, skipping this if we're setting things
7439 during initialization.
7449 # These options need a value. Don't allow them to be clobbered by accident.
7450 my %opt_needs_val = map { ( $_ => 1 ) } qw{
7451 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
7452 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
7455 while (length($s)) {
7458 # Clean off excess leading whitespace.
7459 $s =~ s/^\s+// && next;
7461 # Options are always all word characters, followed by a non-word
7463 if ($s !~ s/^(\w+)(\W?)//) {
7464 print {$OUT} "Invalid option '$s'\n";
7467 my ( $opt, $sep ) = ( $1, $2 );
7469 # Make sure that such an option exists.
7470 my $matches = ( grep { /^\Q$opt/ && ( $option = $_ ) } @options )
7471 || ( grep { /^\Q$opt/i && ( $option = $_ ) } @options );
7474 print {$OUT} "Unknown option '$opt'\n";
7478 print {$OUT} "Ambiguous option '$opt'\n";
7483 # '?' as separator means query, but must have whitespace after it.
7484 if ( "?" eq $sep ) {
7486 print {$OUT} "Option query '$opt?' followed by non-space '$s'\n" ;
7491 #&dump_option($opt);
7492 } ## end if ("?" eq $sep)
7494 # Separator is whitespace (or just a carriage return).
7495 # They're going for a default, which we assume is 1.
7496 elsif ( $sep !~ /\S/ ) {
7498 $val = "1"; # this is an evil default; make 'em set it!
7501 # Separator is =. Trying to set a value.
7502 elsif ( $sep eq "=" ) {
7504 # If quoted, extract a quoted string.
7505 if ($s =~ s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
7507 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
7510 # Not quoted. Use the whole thing. Warn about 'option='.
7514 print OUT qq(Option better cleared using $opt=""\n)
7516 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
7518 } ## end elsif ($sep eq "=")
7520 # "Quoted" with [], <>, or {}.
7521 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
7523 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
7524 $s =~ s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
7525 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last;
7526 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
7527 } ## end else [ if ("?" eq $sep)
7529 # Exclude non-booleans from getting set to 1 by default.
7530 if ( $opt_needs_val{$option} && $val_defaulted ) {
7531 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
7533 "Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n";
7535 } ## end if ($opt_needs_val{$option...
7537 # Save the option value.
7538 $option{$option} = $val if defined $val;
7540 # Load any module that this option requires.
7541 if ( defined($optionRequire{$option}) && defined($val) ) {
7545 require '$optionRequire{$option}';
7547 } || die $@ # XXX: shouldn't happen
7551 # Stick it in the proper variable if it goes in a variable.
7552 if (defined($optionVars{$option}) && defined($val)) {
7553 ${ $optionVars{$option} } = $val;
7556 # Call the appropriate sub if it gets set via sub.
7557 if (defined($optionAction{$option})
7558 && defined (&{ $optionAction{$option} })
7561 &{ $optionAction{$option} }($val);
7564 # Not initialization - echo the value we set it to.
7565 dump_option($option) if ($OUT ne \*STDERR);
7566 } ## end while (length)
7567 } ## end sub parse_options
7569 =head1 RESTART SUPPORT
7571 These routines are used to store (and restore) lists of items in environment
7572 variables during a restart.
7576 Set_list packages up items to be stored in a set of environment variables
7577 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
7578 the values). Values outside the standard ASCII charset are stored by encoding
7579 them as hexadecimal values.
7584 my ( $stem, @list ) = @_;
7587 # VAR_n: how many we have. Scalar assignment gets the number of items.
7588 $ENV{"${stem}_n"} = @list;
7590 # Grab each item in the list, escape the backslashes, encode the non-ASCII
7591 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
7592 for my $i ( 0 .. $#list ) {
7594 $val =~ s/\\/\\\\/g;
7595 no warnings 'experimental::regex_sets';
7596 $val =~ s/ ( (?[ [\000-\xFF] & [:^print:] ]) ) /
7597 "\\0x" . unpack('H2',$1)/xaeg;
7598 $ENV{"${stem}_$i"} = $val;
7599 } ## end for $i (0 .. $#list)
7600 } ## end sub set_list
7604 Reverse the set_list operation: grab VAR_n to see how many we should be getting
7605 back, and then pull VAR_0, VAR_1. etc. back out.
7612 my $n = delete $ENV{"${stem}_n"};
7614 for my $i ( 0 .. $n - 1 ) {
7615 $val = delete $ENV{"${stem}_$i"};
7616 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
7620 } ## end sub get_list
7622 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
7626 The C<catch()> subroutine is the essence of fast and low-impact. We simply
7627 set an already-existing global scalar variable to a constant value. This
7628 avoids allocating any memory possibly in the middle of something that will
7629 get all confused if we do, particularly under I<unsafe signals>.
7635 return; # Put nothing on the stack - malloc/free land!
7640 C<warn> emits a warning, by joining together its arguments and printing
7641 them, with couple of fillips.
7643 If the composited message I<doesn't> end with a newline, we automatically
7644 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
7645 to be set to the filehandle to be used to output warnings; it makes no
7646 assumptions about what filehandles are available.
7651 my ($msg) = join( "", @_ );
7652 $msg .= ": $!\n" unless $msg =~ /\n$/;
7659 =head1 INITIALIZATION TTY SUPPORT
7661 =head2 C<reset_IN_OUT>
7663 This routine handles restoring the debugger's input and output filehandles
7664 after we've tried and failed to move them elsewhere. In addition, it assigns
7665 the debugger's output filehandle to $LINEINFO if it was already open there.
7670 my $switch_li = $LINEINFO eq $OUT;
7672 # If there's a term and it's able to get a new tty, try to get one.
7673 if ( $term and $term->Features->{newTTY} ) {
7674 ( $IN, $OUT ) = ( shift, shift );
7675 $term->newTTY( $IN, $OUT );
7678 # This term can't get a new tty now. Better luck later.
7680 _db_warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n");
7683 # Set the filehndles up as they were.
7685 ( $IN, $OUT ) = ( shift, shift );
7688 # Unbuffer the output filehandle.
7691 # Point LINEINFO to the same output filehandle if it was there before.
7692 $LINEINFO = $OUT if $switch_li;
7693 } ## end sub reset_IN_OUT
7695 =head1 OPTION SUPPORT ROUTINES
7697 The following routines are used to process some of the more complicated
7702 Sets the input and output filehandles to the specified files or pipes.
7703 If the terminal supports switching, we go ahead and do it. If not, and
7704 there's already a terminal in place, we save the information to take effect
7707 If there's no terminal yet (for instance, during debugger initialization),
7708 we go ahead and set C<$console> and C<$tty> to the file indicated.
7714 if ( @_ and $term and $term->Features->{newTTY} ) {
7716 # This terminal supports switching to a new TTY.
7717 # Can be a list of two files, or on string containing both names,
7719 # XXX Should this perhaps be an assignment from @_?
7720 my ( $in, $out ) = shift;
7723 # Split list apart if supplied.
7724 ( $in, $out ) = split /,/, $in, 2;
7728 # Use the same file for both input and output.
7732 # Open file onto the debugger's filehandles, if you can.
7733 open IN, $in or die "cannot open '$in' for read: $!";
7734 open OUT, ">$out" or die "cannot open '$out' for write: $!";
7736 # Swap to the new filehandles.
7737 reset_IN_OUT( \*IN, \*OUT );
7739 # Save the setting for later.
7741 } ## end if (@_ and $term and $term...
7743 # Terminal doesn't support new TTY, or doesn't support readline.
7744 # Can't do it now, try restarting.
7746 _db_warn("Too late to set TTY, enabled on next 'R'!\n");
7749 # Useful if done through PERLDB_OPTS:
7750 $console = $tty = shift if @_;
7752 # Return whatever the TTY is.
7758 Sets the C<$notty> global, controlling whether or not the debugger tries to
7759 get a terminal to read from. If called after a terminal is already in place,
7760 we save the value to use it if we're restarted.
7766 _db_warn("Too late to set noTTY, enabled on next 'R'!\n") if @_;
7768 $notty = shift if @_;
7774 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
7775 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
7776 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
7777 the value in case a restart is done so we can change it then.
7783 _db_warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_;
7787 } ## end sub ReadLine
7789 =head2 C<RemotePort>
7791 Sets the port that the debugger will try to connect to when starting up.
7792 If the terminal's already been set up, we can't do it, but we remember the
7793 setting in case the user does a restart.
7799 _db_warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
7801 $remoteport = shift if @_;
7803 } ## end sub RemotePort
7807 Checks with the terminal to see if C<Tk> is running, and returns true or
7808 false. Returns false if the current terminal doesn't support C<readline>.
7813 if ( ${ $term->Features }{tkRunning} ) {
7814 return $term->tkRunning(@_);
7818 print $OUT "tkRunning not supported by current ReadLine package.\n";
7821 } ## end sub tkRunning
7825 Sets nonstop mode. If a terminal's already been set up, it's too late; the
7826 debugger remembers the setting in case you restart, though.
7832 _db_warn("Too late to set up NonStop mode, enabled on next 'R'!\n")
7835 $runnonstop = shift if @_;
7837 } ## end sub NonStop
7841 _db_warn("Some flag changes could not take effect until next 'R'!\n")
7844 $^P = parse_DollarCaretP_flags(shift) if @_;
7845 expand_DollarCaretP_flags($^P);
7850 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
7858 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7865 Sets the shell escape command, and generates a printable copy to be used
7872 # If we got an argument, meta-quote it, and add '\b' if it
7873 # ends in a word character.
7875 $sh = quotemeta shift;
7876 $sh .= "\\b" if $sh =~ /\w$/;
7879 # Generate the printable version for the help:
7880 $psh = $sh; # copy it
7881 $psh =~ s/\\b$//; # Take off trailing \b if any
7882 $psh =~ s/\\(.)/$1/g; # De-escape
7883 $psh; # return the printable version
7884 } ## end sub shellBang
7888 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7889 was passed as the argument. (This means you can't override the terminal's
7895 if ( defined $term ) {
7897 # We don't want to show warning backtraces, but we do want die() ones.
7898 local $warnLevel = 0;
7899 local $dieLevel = 1;
7901 # No ornaments if the terminal doesn't support them.
7902 if (not $term->Features->{ornaments}) {
7906 return (eval { $term->ornaments(@_) } || '');
7909 # Use what was passed in if we can't determine it ourselves.
7916 } ## end sub ornaments
7918 =head2 C<recallCommand>
7920 Sets the recall command, and builds a printable version which will appear in
7927 # If there is input, metaquote it. Add '\b' if it ends with a word
7930 $rc = quotemeta shift;
7931 $rc .= "\\b" if $rc =~ /\w$/;
7934 # Build it into a printable version.
7935 $prc = $rc; # Copy it
7936 $prc =~ s/\\b$//; # Remove trailing \b
7937 $prc =~ s/\\(.)/$1/g; # Remove escapes
7938 return $prc; # Return the printable version
7939 } ## end sub recallCommand
7941 =head2 C<LineInfo> - where the line number information goes
7943 Called with no arguments, returns the file or pipe that line info should go to.
7945 Called with an argument (a file or a pipe), it opens that onto the
7946 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7947 file or pipe again to the caller.
7955 # If this is a valid "thing to be opened for output", tack a
7956 # '>' onto the front.
7957 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7959 # If this is a pipe, the stream points to a slave editor.
7960 $slave_editor = ( $stream =~ /^\|/ );
7962 my $new_lineinfo_fh;
7963 # Open it up and unbuffer it.
7964 open ($new_lineinfo_fh , $stream )
7965 or _db_warn("Cannot open '$stream' for write");
7966 $LINEINFO = $new_lineinfo_fh;
7967 _autoflush($LINEINFO);
7971 } ## end sub LineInfo
7973 =head1 COMMAND SUPPORT ROUTINES
7975 These subroutines provide functionality for various commands.
7977 =head2 C<list_modules>
7979 For the C<M> command: list modules loaded and their versions.
7980 Essentially just runs through the keys in %INC, picks each package's
7981 C<$VERSION> variable, gets the file name, and formats the information
7986 sub list_modules { # versions
7990 # keys are the "as-loaded" name, values are the fully-qualified path
7991 # to the file itself.
7993 $file = $_; # get the module name
7994 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7995 s,/,::,g; # change '/' to '::'
7996 s/^perl5db$/DB/; # Special case: debugger
7997 # moves to package DB
7998 s/^Term::ReadLine::readline$/readline/; # simplify readline
8000 # If the package has a $VERSION package global (as all good packages
8001 # should!) decode it and save as partial message.
8002 my $pkg_version = do { no strict 'refs'; ${ $_ . '::VERSION' } };
8003 if ( defined $pkg_version ) {
8004 $version{$file} = "$pkg_version from ";
8007 # Finish up the message with the file the package came from.
8008 $version{$file} .= $INC{$file};
8009 } ## end for (keys %INC)
8011 # Hey, dumpit() formats a hash nicely, so why not use it?
8012 dumpit( $OUT, \%version );
8013 } ## end sub list_modules
8017 Sets up the monster string used to format and print the help.
8019 =head3 HELP MESSAGE FORMAT
8021 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
8022 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
8023 easy to parse and portable, but which still allows the help to be a little
8024 nicer than just plain text.
8026 Essentially, you define the command name (usually marked up with C<< B<> >>
8027 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
8028 newline. The descriptive text can also be marked up in the same way. If you
8029 need to continue the descriptive text to another line, start that line with
8030 just tabs and then enter the marked-up text.
8032 If you are modifying the help text, I<be careful>. The help-string parser is
8033 not very sophisticated, and if you don't follow these rules it will mangle the
8034 help beyond hope until you fix the string.
8038 use vars qw($pre580_help);
8039 use vars qw($pre580_summary);
8043 # XXX: make sure there are tabs between the command and explanation,
8044 # or print_help will screw up your formatting if you have
8045 # eeevil ornaments enabled. This is an insane mess.
8048 Help is currently only available for the new 5.8 command set.
8049 No help is available for the old command set.
8050 We assume you know what you're doing if you switch to it.
8053 B<s> [I<expr>] Single step [in I<expr>].
8054 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
8055 <B<CR>> Repeat last B<n> or B<s> command.
8056 B<r> Return from current subroutine.
8057 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
8058 at the specified position.
8059 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
8060 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
8061 B<l> I<line> List single I<line>.
8062 B<l> I<subname> List first window of lines from subroutine.
8063 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
8064 B<l> List next window of lines.
8065 B<-> List previous window of lines.
8066 B<v> [I<line>] View window around I<line>.
8067 B<.> Return to the executed line.
8068 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
8069 I<filename> may be either the full name of the file, or a regular
8070 expression matching the full file name:
8071 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
8072 Evals (with saved bodies) are considered to be filenames:
8073 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
8074 (in the order of execution).
8075 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
8076 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
8077 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
8078 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
8079 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth).
8080 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
8081 B<b> Sets breakpoint on current line)
8082 B<b> [I<line>] [I<condition>]
8083 Set breakpoint; I<line> defaults to the current execution line;
8084 I<condition> breaks if it evaluates to true, defaults to '1'.
8085 B<b> I<subname> [I<condition>]
8086 Set breakpoint at first line of subroutine.
8087 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
8088 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
8089 B<b> B<postpone> I<subname> [I<condition>]
8090 Set breakpoint at first line of subroutine after
8092 B<b> B<compile> I<subname>
8093 Stop after the subroutine is compiled.
8094 B<B> [I<line>] Delete the breakpoint for I<line>.
8095 B<B> I<*> Delete all breakpoints.
8096 B<a> [I<line>] I<command>
8097 Set an action to be done before the I<line> is executed;
8098 I<line> defaults to the current execution line.
8099 Sequence is: check for breakpoint/watchpoint, print line
8100 if necessary, do action, prompt user if necessary,
8103 B<A> [I<line>] Delete the action for I<line>.
8104 B<A> I<*> Delete all actions.
8105 B<w> I<expr> Add a global watch-expression.
8107 B<W> I<expr> Delete a global watch-expression.
8108 B<W> I<*> Delete all watch-expressions.
8109 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
8110 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
8111 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
8112 B<x> I<expr> Evals expression in list context, dumps the result.
8113 B<m> I<expr> Evals expression in list context, prints methods callable
8114 on the first element of the result.
8115 B<m> I<class> Prints methods callable via the given class.
8116 B<M> Show versions of loaded modules.
8117 B<i> I<class> Prints nested parents of given class.
8118 B<e> Display current thread id.
8119 B<E> Display all thread ids the current one will be identified: <n>.
8120 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8122 B<<> ? List Perl commands to run before each prompt.
8123 B<<> I<expr> Define Perl command to run before each prompt.
8124 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
8125 B<< *> Delete the list of perl commands to run before each prompt.
8126 B<>> ? List Perl commands to run after each prompt.
8127 B<>> I<expr> Define Perl command to run after each prompt.
8128 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
8129 B<>>B< *> Delete the list of Perl commands to run after each prompt.
8130 B<{> I<db_command> Define debugger command to run before each prompt.
8131 B<{> ? List debugger commands to run before each prompt.
8132 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
8133 B<{ *> Delete the list of debugger commands to run before each prompt.
8134 B<$prc> I<number> Redo a previous command (default previous command).
8135 B<$prc> I<-number> Redo number'th-to-last command.
8136 B<$prc> I<pattern> Redo last command that started with I<pattern>.
8137 See 'B<O> I<recallCommand>' too.
8138 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
8143 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
8145 See 'B<O> I<shellBang>' too.
8146 B<source> I<file> Execute I<file> containing debugger commands (may nest).
8147 B<save> I<file> Save current debugger session (actual history) to I<file>.
8148 B<rerun> Rerun session to current position.
8149 B<rerun> I<n> Rerun session to numbered command.
8150 B<rerun> I<-n> Rerun session to number'th-to-last command.
8151 B<H> I<-number> Display last number commands (default all).
8152 B<H> I<*> Delete complete history.
8153 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
8154 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
8155 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well.
8156 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
8157 I<command> Execute as a perl statement in current package.
8158 B<R> Pure-man-restart of debugger, some of debugger state
8159 and command-line options may be lost.
8160 Currently the following settings are preserved:
8161 history, breakpoints and actions, debugger B<O>ptions
8162 and the following command-line options: I<-w>, I<-I>, I<-e>.
8164 B<o> [I<opt>] ... Set boolean option to true
8165 B<o> [I<opt>B<?>] Query options
8166 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
8167 Set options. Use quotes if spaces in value.
8168 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
8169 I<pager> program for output of \"|cmd\";
8170 I<tkRunning> run Tk while prompting (with ReadLine);
8171 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
8172 I<inhibit_exit> Allows stepping off the end of the script.
8173 I<ImmediateStop> Debugger should stop as early as possible.
8174 I<RemotePort> Remote hostname:port for remote debugging
8175 The following options affect what happens with B<V>, B<X>, and B<x> commands:
8176 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
8177 I<compactDump>, I<veryCompact> change style of array and hash dump;
8178 I<globPrint> whether to print contents of globs;
8179 I<DumpDBFiles> dump arrays holding debugged files;
8180 I<DumpPackages> dump symbol tables of packages;
8181 I<DumpReused> dump contents of \"reused\" addresses;
8182 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
8183 I<bareStringify> Do not print the overload-stringified value;
8184 Other options include:
8185 I<PrintRet> affects printing of return value after B<r> command,
8186 I<frame> affects printing messages on subroutine entry/exit.
8187 I<AutoTrace> affects printing messages on possible breaking points.
8188 I<maxTraceLen> gives max length of evals/args listed in stack trace.
8189 I<ornaments> affects screen appearance of the command line.
8190 I<CreateTTY> bits control attempts to create a new TTY on events:
8191 1: on fork() 2: debugger is started inside debugger
8193 During startup options are initialized from \$ENV{PERLDB_OPTS}.
8194 You can put additional initialization options I<TTY>, I<noTTY>,
8195 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
8196 B<R> after you set them).
8198 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
8199 B<h> Summary of debugger commands.
8200 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
8201 B<h h> Long help for debugger commands
8202 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
8203 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
8204 Set B<\$DB::doccmd> to change viewer.
8206 Type '|h h' for a paged display if this was too hard to read.
8208 "; # Fix balance of vi % matching: }}}}
8210 # note: tabs in the following section are not-so-helpful
8211 $summary = <<"END_SUM";
8212 I<List/search source lines:> I<Control script execution:>
8213 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8214 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8215 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
8216 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8217 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8218 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
8219 I<Debugger controls:> B<L> List break/watch/actions
8220 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr]
8221 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8222 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
8223 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8224 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
8225 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
8226 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
8227 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8228 B<q> or B<^D> Quit B<R> Attempt a restart
8229 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8230 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8231 B<p> I<expr> Print expression (uses script's current package).
8232 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8233 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8234 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
8235 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8236 B<e> Display thread id B<E> Display all thread ids.
8237 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8240 # ')}}; # Fix balance of vi % matching
8242 # and this is really numb...
8245 B<s> [I<expr>] Single step [in I<expr>].
8246 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
8247 B<CR>> Repeat last B<n> or B<s> command.
8248 B<r> Return from current subroutine.
8249 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
8250 at the specified position.
8251 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
8252 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
8253 B<l> I<line> List single I<line>.
8254 B<l> I<subname> List first window of lines from subroutine.
8255 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
8256 B<l> List next window of lines.
8257 B<-> List previous window of lines.
8258 B<w> [I<line>] List window around I<line>.
8259 B<.> Return to the executed line.
8260 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
8261 I<filename> may be either the full name of the file, or a regular
8262 expression matching the full file name:
8263 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
8264 Evals (with saved bodies) are considered to be filenames:
8265 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
8266 (in the order of execution).
8267 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
8268 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
8269 B<L> List all breakpoints and actions.
8270 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
8271 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) .
8272 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
8273 B<b> [I<line>] [I<condition>]
8274 Set breakpoint; I<line> defaults to the current execution line;
8275 I<condition> breaks if it evaluates to true, defaults to '1'.
8276 B<b> I<subname> [I<condition>]
8277 Set breakpoint at first line of subroutine.
8278 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
8279 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
8280 B<b> B<postpone> I<subname> [I<condition>]
8281 Set breakpoint at first line of subroutine after
8283 B<b> B<compile> I<subname>
8284 Stop after the subroutine is compiled.
8285 B<d> [I<line>] Delete the breakpoint for I<line>.
8286 B<D> Delete all breakpoints.
8287 B<a> [I<line>] I<command>
8288 Set an action to be done before the I<line> is executed;
8289 I<line> defaults to the current execution line.
8290 Sequence is: check for breakpoint/watchpoint, print line
8291 if necessary, do action, prompt user if necessary,
8293 B<a> [I<line>] Delete the action for I<line>.
8294 B<A> Delete all actions.
8295 B<W> I<expr> Add a global watch-expression.
8296 B<W> Delete all watch-expressions.
8297 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
8298 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
8299 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
8300 B<x> I<expr> Evals expression in list context, dumps the result.
8301 B<m> I<expr> Evals expression in list context, prints methods callable
8302 on the first element of the result.
8303 B<m> I<class> Prints methods callable via the given class.
8305 B<<> ? List Perl commands to run before each prompt.
8306 B<<> I<expr> Define Perl command to run before each prompt.
8307 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
8308 B<>> ? List Perl commands to run after each prompt.
8309 B<>> I<expr> Define Perl command to run after each prompt.
8310 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
8311 B<{> I<db_command> Define debugger command to run before each prompt.
8312 B<{> ? List debugger commands to run before each prompt.
8313 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
8314 B<$prc> I<number> Redo a previous command (default previous command).
8315 B<$prc> I<-number> Redo number'th-to-last command.
8316 B<$prc> I<pattern> Redo last command that started with I<pattern>.
8317 See 'B<O> I<recallCommand>' too.
8318 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
8323 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
8325 See 'B<O> I<shellBang>' too.
8326 B<source> I<file> Execute I<file> containing debugger commands (may nest).
8327 B<H> I<-number> Display last number commands (default all).
8328 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
8329 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
8330 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
8331 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
8332 I<command> Execute as a perl statement in current package.
8333 B<v> Show versions of loaded modules.
8334 B<R> Pure-man-restart of debugger, some of debugger state
8335 and command-line options may be lost.
8336 Currently the following settings are preserved:
8337 history, breakpoints and actions, debugger B<O>ptions
8338 and the following command-line options: I<-w>, I<-I>, I<-e>.
8340 B<O> [I<opt>] ... Set boolean option to true
8341 B<O> [I<opt>B<?>] Query options
8342 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
8343 Set options. Use quotes if spaces in value.
8344 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
8345 I<pager> program for output of \"|cmd\";
8346 I<tkRunning> run Tk while prompting (with ReadLine);
8347 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
8348 I<inhibit_exit> Allows stepping off the end of the script.
8349 I<ImmediateStop> Debugger should stop as early as possible.
8350 I<RemotePort> Remote hostname:port for remote debugging
8351 The following options affect what happens with B<V>, B<X>, and B<x> commands:
8352 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
8353 I<compactDump>, I<veryCompact> change style of array and hash dump;
8354 I<globPrint> whether to print contents of globs;
8355 I<DumpDBFiles> dump arrays holding debugged files;
8356 I<DumpPackages> dump symbol tables of packages;
8357 I<DumpReused> dump contents of \"reused\" addresses;
8358 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
8359 I<bareStringify> Do not print the overload-stringified value;
8360 Other options include:
8361 I<PrintRet> affects printing of return value after B<r> command,
8362 I<frame> affects printing messages on subroutine entry/exit.
8363 I<AutoTrace> affects printing messages on possible breaking points.
8364 I<maxTraceLen> gives max length of evals/args listed in stack trace.
8365 I<ornaments> affects screen appearance of the command line.
8366 I<CreateTTY> bits control attempts to create a new TTY on events:
8367 1: on fork() 2: debugger is started inside debugger
8369 During startup options are initialized from \$ENV{PERLDB_OPTS}.
8370 You can put additional initialization options I<TTY>, I<noTTY>,
8371 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
8372 B<R> after you set them).
8374 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
8375 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
8376 B<h h> Summary of debugger commands.
8377 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
8378 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
8379 Set B<\$DB::doccmd> to change viewer.
8381 Type '|h' for a paged display if this was too hard to read.
8383 "; # Fix balance of vi % matching: }}}}
8385 # note: tabs in the following section are not-so-helpful
8386 $pre580_summary = <<"END_SUM";
8387 I<List/search source lines:> I<Control script execution:>
8388 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8389 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8390 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
8391 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8392 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8393 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
8394 I<Debugger controls:> B<L> List break/watch/actions
8395 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
8396 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8397 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
8398 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8399 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
8400 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
8401 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8402 B<q> or B<^D> Quit B<R> Attempt a restart
8403 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8404 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8405 B<p> I<expr> Print expression (uses script's current package).
8406 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8407 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8408 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
8409 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8410 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8413 # ')}}; # Fix balance of vi % matching
8415 } ## end sub sethelp
8417 =head2 C<print_help()>
8419 Most of what C<print_help> does is just text formatting. It finds the
8420 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
8421 terminal control characters to simulate them (courtesy of
8422 C<Term::ReadLine::TermCap>).
8427 my $help_str = shift;
8429 # Restore proper alignment destroyed by eeevil I<> and B<>
8430 # ornaments: A pox on both their houses!
8432 # A help command will have everything up to and including
8433 # the first tab sequence padded into a field 16 (or if indented 20)
8434 # wide. If it's wider than that, an extra space will be added.
8436 ^ # only matters at start of line
8437 ( \ {4} | \t )* # some subcommands are indented
8438 ( < ? # so <CR> works
8439 [BI] < [^\t\n] + ) # find an eeevil ornament
8440 ( \t+ ) # original separation, discarded
8441 ( .* ) # this will now start (no earlier) than
8444 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
8445 my $clean = $command;
8446 $clean =~ s/[BI]<([^>]*)>/$1/g;
8448 # replace with this whole string:
8449 ($leadwhite ? " " x 4 : "")
8451 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
8456 $help_str =~ s{ # handle bold ornaments
8457 B < ( [^>] + | > ) >
8459 $Term::ReadLine::TermCap::rl_term_set[2]
8461 . $Term::ReadLine::TermCap::rl_term_set[3]
8464 $help_str =~ s{ # handle italic ornaments
8465 I < ( [^>] + | > ) >
8467 $Term::ReadLine::TermCap::rl_term_set[0]
8469 . $Term::ReadLine::TermCap::rl_term_set[1]
8473 print {$OUT} $help_str;
8476 } ## end sub print_help
8480 This routine does a lot of gyrations to be sure that the pager is C<less>.
8481 It checks for C<less> masquerading as C<more> and records the result in
8482 C<$fixed_less> so we don't have to go through doing the stats again.
8486 use vars qw($fixed_less);
8489 if ($pager =~ /\bless\b/)
8493 elsif ($pager =~ /\bmore\b/)
8495 # Nope, set to more. See what's out there.
8496 my @st_more = stat('/usr/bin/more');
8497 my @st_less = stat('/usr/bin/less');
8499 # is it really less, pretending to be more?
8503 && $st_more[0] == $st_less[0]
8504 && $st_more[1] == $st_less[1]
8514 # We already know if this is set.
8515 return if $fixed_less;
8517 # changes environment!
8518 # 'r' added so we don't do (slow) stats again.
8519 $fixed_less = 1 if _calc_is_less();
8522 } ## end sub fix_less
8524 =head1 DIE AND WARN MANAGEMENT
8528 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
8529 to debug a debugger problem.
8531 It does its best to report the error that occurred, and then forces the
8532 program, debugger, and everything to die.
8538 # No entry/exit messages.
8541 # No return value prints.
8544 # set the abort signal handling to the default (just terminate).
8545 $SIG{'ABRT'} = 'DEFAULT';
8547 # If we enter the signal handler recursively, kill myself with an
8548 # abort signal (so we just terminate).
8549 kill 'ABRT', $$ if $panic++;
8551 # If we can show detailed info, do so.
8552 if ( defined &Carp::longmess ) {
8554 # Don't recursively enter the warn handler, since we're carping.
8555 local $SIG{__WARN__} = '';
8557 # Skip two levels before reporting traceback: we're skipping
8558 # mydie and confess.
8559 local $Carp::CarpLevel = 2; # mydie + confess
8561 # Tell us all about it.
8562 _db_warn( Carp::longmess("Signal @_") );
8565 # No Carp. Tell us about the signal as best we can.
8568 print $DB::OUT "Got signal @_\n";
8573 } ## end sub diesignal
8577 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
8578 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
8584 # No entry/exit trace.
8587 # No return value printing.
8590 # Turn off warn and die handling to prevent recursive entries to this
8592 local $SIG{__WARN__} = '';
8593 local $SIG{__DIE__} = '';
8595 # Load Carp if we can. If $^S is false (current thing being compiled isn't
8596 # done yet), we may not be able to do a require.
8597 eval { require Carp }
8598 if defined $^S; # If error/warning during compilation,
8599 # require may be broken.
8601 # Use the core warn() unless Carp loaded OK.
8603 "\nCannot print stack trace, load with -MCarp option to see stack" ),
8605 unless defined &Carp::longmess;
8607 # Save the current values of $single and $trace, and then turn them off.
8608 my ( $mysingle, $mytrace ) = ( $single, $trace );
8612 # We can call Carp::longmess without its being "debugged" (which we
8613 # don't want - we just want to use it!). Capture this for later.
8614 my $mess = Carp::longmess(@_);
8616 # Restore $single and $trace to their original values.
8617 ( $single, $trace ) = ( $mysingle, $mytrace );
8619 # Use the debugger's own special way of printing warnings to print
8620 # the stack trace message.
8626 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
8627 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
8628 single stepping and tracing during the call to C<Carp::longmess> to avoid
8629 debugging it - we just want to use it.
8631 If C<dieLevel> is zero, we let the program being debugged handle the
8632 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
8633 the debugger takes over all exception handling, printing a backtrace and
8634 displaying the exception via its C<dbwarn()> routine.
8641 local $SIG{__DIE__} = '';
8642 local $SIG{__WARN__} = '';
8643 if ( $dieLevel > 2 ) {
8644 local $SIG{__WARN__} = \&dbwarn;
8645 _db_warn(@_); # Yell no matter what
8648 if ( $dieLevel < 2 ) {
8649 die @_ if $^S; # in eval propagate
8652 # The code used to check $^S to see if compilation of the current thing
8653 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
8654 eval { require Carp };
8657 "\nCannot print stack trace, load with -MCarp option to see stack" )
8658 unless defined &Carp::longmess;
8660 # We do not want to debug this chunk (automatic disabling works
8661 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
8662 # get the stack trace from Carp::longmess (if possible), restore $signal
8663 # and $trace, and then die with the stack trace.
8664 my ( $mysingle, $mytrace ) = ( $single, $trace );
8670 package Carp; # Do not include us in the list
8671 eval { $mess = Carp::longmess(@_); };
8673 ( $single, $trace ) = ( $mysingle, $mytrace );
8677 =head2 C<warnlevel()>
8679 Set the C<$DB::warnLevel> variable that stores the value of the
8680 C<warnLevel> option. Calling C<warnLevel()> with a positive value
8681 results in the debugger taking over all warning handlers. Setting
8682 C<warnLevel> to zero leaves any warning handlers set up by the program
8683 being debugged in place.
8689 my $prevwarn = $SIG{__WARN__} unless $warnLevel;
8692 $SIG{__WARN__} = \&DB::dbwarn;
8695 $SIG{__WARN__} = $prevwarn;
8697 undef $SIG{__WARN__};
8701 } ## end sub warnLevel
8705 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
8706 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
8707 zero lets you use your own C<die()> handler.
8714 my $prevdie = $SIG{__DIE__} unless $dieLevel;
8718 # Always set it to dbdie() for non-zero values.
8719 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
8721 # No longer exists, so don't try to use it.
8722 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
8724 # If we've finished initialization, mention that stack dumps
8725 # are enabled, If dieLevel is 1, we won't stack dump if we die
8727 print $OUT "Stack dump during die enabled",
8728 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
8731 # XXX This is probably obsolete, given that diehard() is gone.
8732 print $OUT "Dump printed too.\n" if $dieLevel > 2;
8733 } ## end if ($dieLevel)
8735 # Put the old one back if there was one.
8737 $SIG{__DIE__} = $prevdie;
8738 print $OUT "Default die handler restored.\n";
8740 undef $SIG{__DIE__};
8741 print $OUT "Die handler removed.\n";
8745 } ## end sub dieLevel
8747 =head2 C<signalLevel>
8749 Number three in a series: set C<signalLevel> to zero to keep your own
8750 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
8751 takes over and handles them with C<DB::diesignal()>.
8757 my $prevsegv = $SIG{SEGV} unless $signalLevel;
8758 my $prevbus = $SIG{BUS} unless $signalLevel;
8759 $signalLevel = shift;
8761 $SIG{SEGV} = \&DB::diesignal;
8762 $SIG{BUS} = \&DB::diesignal;
8765 $SIG{SEGV} = $prevsegv;
8766 $SIG{BUS} = $prevbus;
8770 } ## end sub signalLevel
8772 =head1 SUBROUTINE DECODING SUPPORT
8774 These subroutines are used during the C<x> and C<X> commands to try to
8775 produce as much information as possible about a code reference. They use
8776 L<Devel::Peek> to try to find the glob in which this code reference lives
8777 (if it does) - this allows us to actually code references which correspond
8778 to named subroutines (including those aliased via glob assignment).
8780 =head2 C<CvGV_name()>
8782 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
8783 via that routine. If this fails, return the reference again (when the
8784 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
8790 my $name = CvGV_name_or_bust($in);
8791 defined $name ? $name : $in;
8794 =head2 C<CvGV_name_or_bust> I<coderef>
8796 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
8797 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
8798 find a glob for this ref.
8800 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
8804 use vars qw($skipCvGV);
8806 sub CvGV_name_or_bust {
8808 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
8809 return unless ref $in;
8810 $in = \&$in; # Hard reference...
8811 eval { require Devel::Peek; 1 } or return;
8812 my $gv = Devel::Peek::CvGV($in) or return;
8813 *$gv{PACKAGE} . '::' . *$gv{NAME};
8814 } ## end sub CvGV_name_or_bust
8818 A utility routine used in various places; finds the file where a subroutine
8819 was defined, and returns that filename and a line-number range.
8821 Tries to use C<@sub> first; if it can't find it there, it tries building a
8822 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
8823 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
8824 this way, it brute-force searches C<%sub>, checking for identical references.
8828 sub _find_sub_helper {
8831 return unless defined &$subr;
8832 my $name = CvGV_name_or_bust($subr);
8834 $data = $sub{$name} if defined $name;
8835 return $data if defined $data;
8838 $subr = \&$subr; # Hard reference
8841 $s = $_, last if $subr eq \&$_;
8856 return ( $sub{$subr} || _find_sub_helper($subr) );
8857 } ## end sub find_sub
8861 A subroutine that uses the utility function C<methods_via> to find all the
8862 methods in the class corresponding to the current reference and in
8871 # Figure out the class - either this is the class or it's a reference
8872 # to something blessed into that class.
8874 $class = ref $class if ref $class;
8878 # Show the methods that this class has.
8879 methods_via( $class, '', 1 );
8881 # Show the methods that UNIVERSAL has.
8882 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
8883 } ## end sub methods
8885 =head2 C<methods_via($class, $prefix, $crawl_upward)>
8887 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
8888 all the parent class methods. C<$class> is the name of the next class to
8889 try; C<$prefix> is the message prefix, which gets built up as we go up the
8890 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
8891 higher in the C<@ISA> tree, 0 if we should stop.
8897 # If we've processed this class already, just quit.
8899 return if $seen{$class}++;
8901 # This is a package that is contributing the methods we're about to print.
8903 my $prepend = $prefix ? "via $prefix: " : '';
8906 # Extract from all the symbols in this class.
8907 my $class_ref = do { no strict "refs"; \%{$class . '::'} };
8908 while (my ($name, $glob) = each %$class_ref) {
8909 # references directly in the symbol table are Proxy Constant
8910 # Subroutines, and are by their very nature defined
8911 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8912 # to a subroutine reference, which can be tested by defined.
8913 # $glob might also be the value -1 (from sub foo;)
8914 # or (say) '$$' (from sub foo ($$);)
8915 # \$glob will be SCALAR in both cases.
8916 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8917 && !$seen{$name}++) {
8918 push @to_print, "$prepend$name\n";
8925 print $DB::OUT $_ foreach sort @to_print;
8928 # If the $crawl_upward argument is false, just quit here.
8929 return unless shift;
8931 # $crawl_upward true: keep going up the tree.
8932 # Find all the classes this one is a subclass of.
8933 my $class_ISA_ref = do { no strict "refs"; \@{"${class}::ISA"} };
8934 for my $name ( @$class_ISA_ref ) {
8936 # Set up the new prefix.
8937 $prepend = $prefix ? $prefix . " -> $name" : $name;
8939 # Crawl up the tree and keep trying to crawl up.
8940 methods_via( $name, $prepend, 1 );
8942 } ## end sub methods_via
8944 =head2 C<setman> - figure out which command to use to show documentation
8946 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8951 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|NetWare)\z/s
8952 ? "man" # O Happy Day!
8953 : "perldoc"; # Alas, poor unfortunates
8956 =head2 C<runman> - run the appropriate command to show documentation
8958 Accepts a man page name; runs the appropriate command to display it (set up
8959 during debugger initialization). Uses C<_db_system()> to avoid mucking up the
8960 program's STDIN and STDOUT.
8967 _db_system("$doccmd $doccmd");
8971 # this way user can override, like with $doccmd="man -Mwhatever"
8972 # or even just "man " to disable the path check.
8973 if ( $doccmd ne 'man' ) {
8974 _db_system("$doccmd $page");
8978 $page = 'perl' if lc($page) eq 'help';
8981 my $man1dir = $Config::Config{man1direxp};
8982 my $man3dir = $Config::Config{man3direxp};
8983 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8985 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8986 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8987 chop $manpath if $manpath;
8989 # harmless if missing, I figure
8990 local $ENV{MANPATH} = $manpath if $manpath;
8991 my $nopathopt = $^O =~ /dunno what goes here/;
8996 # I just *know* there are men without -M
8997 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
9002 unless ( $page =~ /^perl\w/ ) {
9003 # Previously the debugger contained a list which it slurped in,
9004 # listing the known "perl" manpages. However, it was out of date,
9005 # with errors both of omission and inclusion. This approach is
9006 # considerably less complex. The failure mode on a butchered
9007 # install is simply that the user has to run man or perldoc
9008 # "manually" with the full manpage name.
9010 # There is a list of $^O values in installperl to determine whether
9011 # the directory is 'pods' or 'pod'. However, we can avoid tight
9012 # coupling to that by simply checking the "non-standard" 'pods'
9014 my $pods = "$Config::Config{privlibexp}/pods";
9015 $pods = "$Config::Config{privlibexp}/pod"
9017 if (-f "$pods/perl$page.pod") {
9018 CORE::system( $doccmd,
9019 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
9023 } ## end if (CORE::system($doccmd...
9026 #use Carp; # This did break, left for debugging
9028 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
9030 Because of the way the debugger interface to the Perl core is designed, any
9031 debugger package globals that C<DB::sub()> requires have to be defined before
9032 any subroutines can be called. These are defined in the second C<BEGIN> block.
9034 This block sets things up so that (basically) the world is sane
9035 before the debugger starts executing. We set up various variables that the
9036 debugger has to have set up before the Perl core starts running:
9042 The debugger's own filehandles (copies of STD and STDOUT for now).
9046 Characters for shell escapes, the recall command, and the history command.
9050 The maximum recursion depth.
9054 The size of a C<w> command's window.
9058 The before-this-line context to be printed in a C<v> (view a window around this line) command.
9062 The fact that we're not in a sub at all right now.
9066 The default SIGINT handler for the debugger.
9070 The appropriate value of the flag in C<$^D> that says the debugger is running
9074 The current debugger recursion level
9078 The list of postponed items and the C<$single> stack (XXX define this)
9082 That we want no return values and no subroutine entry/exit trace.
9088 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
9090 use vars qw($db_stop);
9092 BEGIN { # This does not compile, alas. (XXX eh?)
9093 $IN = \*STDIN; # For bugs before DB::OUT has been opened
9094 $OUT = \*STDERR; # For errors before DB::OUT has been opened
9096 # Define characters used by command parsing.
9097 $sh = '!'; # Shell escape (does not work)
9098 $rc = ','; # Recall command (does not work)
9099 @hist = ('?'); # Show history (does not work)
9100 @truehist = (); # Can be saved for replay (per session)
9102 # This defines the point at which you get the 'deep recursion'
9103 # warning. It MUST be defined or the debugger will not load.
9106 # Number of lines around the current one that are shown in the
9110 # How much before-the-current-line context the 'v' command should
9111 # use in calculating the start of the window it will display.
9114 # We're not in any sub yet, but we need this to be a defined value.
9117 # Set up the debugger's interrupt handler. It simply sets a flag
9118 # ($signal) that DB::DB() will check before each command is executed.
9119 $SIG{INT} = \&DB::catch;
9121 # The following lines supposedly, if uncommented, allow the debugger to
9122 # debug itself. Perhaps we can try that someday.
9123 # This may be enabled to debug debugger:
9124 #$warnLevel = 1 unless defined $warnLevel;
9125 #$dieLevel = 1 unless defined $dieLevel;
9126 #$signalLevel = 1 unless defined $signalLevel;
9128 # This is the flag that says "a debugger is running, please call
9129 # DB::DB and DB::sub". We will turn it on forcibly before we try to
9130 # execute anything in the user's context, because we always want to
9132 $db_stop = 0; # Compiler warning ...
9133 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
9135 # This variable records how many levels we're nested in debugging. Used
9136 # Used in the debugger prompt, and in determining whether it's all over or
9138 $level = 0; # Level of recursive debugging
9140 # "Triggers bug (?) in perl if we postpone this until runtime."
9141 # XXX No details on this yet, or whether we should fix the bug instead
9142 # of work around it. Stay tuned.
9145 # Used to track the current stack depth using the auto-stacked-variable
9147 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
9149 # Don't print return values on exiting a subroutine.
9152 # No extry/exit tracing.
9157 BEGIN { $^W = $ini_warn; } # Switch warnings back
9159 =head1 READLINE SUPPORT - COMPLETION FUNCTION
9163 C<readline> support - adds command completion to basic C<readline>.
9165 Returns a list of possible completions to C<readline> when invoked. C<readline>
9166 will print the longest common substring following the text already entered.
9168 If there is only a single possible completion, C<readline> will use it in full.
9170 This code uses C<map> and C<grep> heavily to create lists of possible
9171 completion. Think LISP in this section.
9177 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
9178 # $text is the text to be completed.
9179 # $line is the incoming line typed by the user.
9180 # $start is the start of the text to be completed in the incoming line.
9181 my ( $text, $line, $start ) = @_;
9183 # Save the initial text.
9184 # The search pattern is current package, ::, extract the next qualifier
9185 # Prefix and pack are set to undef.
9186 my ( $itext, $search, $prefix, $pack ) =
9187 ( $text, "^\Q${package}::\E([^:]+)\$" );
9189 =head3 C<b postpone|compile>
9195 Find all the subroutines that might match in this package
9199 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
9203 Include all the rest of the subs that are known
9207 C<grep> out the ones that match the text we have so far
9211 Return this as the list of possible completions
9217 return sort grep /^\Q$text/, ( keys %sub ),
9218 qw(postpone load compile), # subroutines
9219 ( map { /$search/ ? ($1) : () } keys %sub )
9220 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
9224 Get all the possible files from C<@INC> as it currently stands and
9225 select the ones that match the text so far.
9229 return sort grep /^\Q$text/, values %INC # files
9230 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
9232 =head3 C<V> (list variable) and C<m> (list modules)
9234 There are two entry points for these commands:
9236 =head4 Unqualified package names
9238 Get the top-level packages and grab everything that matches the text
9239 so far. For each match, recursively complete the partial packages to
9240 get all possible matching packages. Return this sorted list.
9244 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9245 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
9246 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
9248 =head4 Qualified package names
9250 Take a partially-qualified package and find all subpackages for it
9251 by getting all the subpackages for the package so far, matching all
9252 the subpackages against the text, and discarding all of them which
9253 start with 'main::'. Return this list.
9257 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9258 grep !/^main::/, grep /^\Q$text/,
9259 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () }
9260 do { no strict 'refs'; keys %{ $prefix . '::' } }
9261 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
9262 and $text =~ /^(.*[^:])::?(\w*)$/
9265 =head3 C<f> - switch files
9267 Here, we want to get a fully-qualified filename for the C<f> command.
9272 =item 1. The original source file itself
9274 =item 2. A file from C<@INC>
9276 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
9282 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
9283 # We might possibly want to switch to an eval (which has a "filename"
9284 # like '(eval 9)'), so we may need to clean up the completion text
9285 # before proceeding.
9286 $prefix = length($1) - length($text);
9291 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
9292 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
9293 out of C<%main::>, add the initial source file, and extract the ones that
9294 match the completion text so far.
9299 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
9301 } ## end if ($line =~ /^\|*f\s+(.*)/)
9303 =head3 Subroutine name completion
9305 We look through all of the defined subs (the keys of C<%sub>) and
9306 return both all the possible matches to the subroutine name plus
9307 all the matches qualified to the current package.
9311 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
9312 $text = substr $text, 1;
9314 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
9316 map { /$search/ ? ($1) : () }
9319 } ## end if ((substr $text, 0, ...
9321 =head3 Scalar, array, and hash completion: partially qualified package
9323 Much like the above, except we have to do a little more cleanup:
9327 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
9335 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
9339 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
9345 Figure out the prefix vs. what needs completing.
9349 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
9356 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
9362 map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
9370 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.
9374 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9375 return db_complete( $out[0], $line, $start );
9378 # Return the list of possibles.
9381 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
9387 =head3 Symbol completion: current package or package C<main>.
9391 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
9398 If it's C<main>, delete main to just get C<::> leading.
9402 $pack = ( $package eq 'main' ? '' : $package ) . '::';
9408 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
9412 $prefix = substr $text, 0, 1;
9413 $text = substr $text, 1;
9421 We look for the lexical scope above DB::DB and auto-complete lexical variables
9422 if PadWalker could be loaded.
9426 if (not $text =~ /::/ and eval { require PadWalker } ) {
9429 my @info = caller($level);
9433 last if $info[3] eq 'DB::DB';
9436 my $lexicals = PadWalker::peek_my($level);
9437 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
9445 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
9449 push @out, map "$prefix$_", grep /^\Q$text/,
9450 ( grep /^_?[a-zA-Z]/, do { no strict 'refs'; keys %$pack } ),
9451 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
9455 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
9461 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9462 return db_complete( $out[0], $line, $start );
9465 # Return the list of possibles.
9467 } ## end if ($text =~ /^[\$@%]/)
9471 We use C<option_val()> to look up the current value of the option. If there's
9472 only a single value, we complete the command in such a way that it is a
9473 complete command for setting the option in question. If there are multiple
9474 possible values, we generate a command consisting of the option plus a trailing
9475 question mark, which, if executed, will list the current value of the option.
9479 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
9480 { # Options after space
9481 # We look for the text to be matched in the list of possible options,
9482 # and fetch the current value.
9483 my @out = grep /^\Q$text/, @options;
9484 my $val = option_val( $out[0], undef );
9486 # Set up a 'query option's value' command.
9488 if ( not defined $val or $val =~ /[\n\r]/ ) {
9490 # There's really nothing else we can do.
9493 # We have a value. Create a proper option-setting command.
9494 elsif ( $val =~ /\s/ ) {
9496 # XXX This may be an extraneous variable.
9499 # We'll want to quote the string (because of the embedded
9500 # whtespace), but we want to make sure we don't end up with
9501 # mismatched quote characters. We try several possibilities.
9502 foreach my $l ( split //, qq/\"\'\#\|/ ) {
9504 # If we didn't find this quote character in the value,
9505 # quote it using this quote character.
9506 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
9508 } ## end elsif ($val =~ /\s/)
9510 # Don't need any quotes.
9515 # If there were multiple possible values, return '? ', which
9516 # makes the command into a query command. If there was just one,
9517 # have readline append that.
9518 $rl_attribs->{completer_terminator_character} =
9519 ( @out == 1 ? $out : '? ' );
9521 # Return list of possibilities.
9523 } ## end if ((substr $line, 0, ...
9525 =head3 Filename completion
9527 For entering filenames. We simply call C<readline>'s C<filename_list()>
9528 method with the completion text to get the possible completions.
9532 return $term->filename_list($text); # filenames
9534 } ## end sub db_complete
9536 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
9538 Functions that possibly ought to be somewhere else.
9548 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n";
9553 If we have $ini_pids, save it in the environment; else remove it from the
9554 environment. Used by the C<R> (restart) command.
9559 if ( defined($ini_pids) ) {
9560 $ENV{PERLDB_PIDS} = $ini_pids;
9563 delete( $ENV{PERLDB_PIDS} );
9565 } ## end sub clean_ENV
9567 # PERLDBf_... flag names from perl.h
9568 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
9571 %DollarCaretP_flags = (
9572 PERLDBf_SUB => 0x01, # Debug sub enter/exit
9573 PERLDBf_LINE => 0x02, # Keep line #
9574 PERLDBf_NOOPT => 0x04, # Switch off optimizations
9575 PERLDBf_INTER => 0x08, # Preserve more data
9576 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
9577 PERLDBf_SINGLE => 0x20, # Start with single-step on
9578 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
9579 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
9580 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
9581 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
9582 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
9583 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
9585 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
9586 # doesn't need to set it. It's provided for the benefit of profilers and
9587 # other code analysers.
9589 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
9592 sub parse_DollarCaretP_flags {
9597 foreach my $f ( split /\s*\|\s*/, $flags ) {
9599 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
9602 elsif ( $f =~ /^(\d+)$/ ) {
9605 elsif ( $f =~ /^DEFAULT$/i ) {
9606 $value = $DollarCaretP_flags{PERLDB_ALL};
9609 $f =~ /^(?:PERLDBf_)?(.*)$/i;
9610 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
9611 unless ( defined $value ) {
9613 "Unrecognized \$^P flag '$f'!\n",
9614 "Acceptable flags are: "
9615 . join( ', ', sort keys %DollarCaretP_flags ),
9616 ", and hexadecimal and decimal numbers.\n"
9626 sub expand_DollarCaretP_flags {
9627 my $DollarCaretP = shift;
9630 my $n = ( 1 << $_ );
9631 ( $DollarCaretP & $n )
9632 ? ( $DollarCaretP_flags_r{$n}
9633 || sprintf( '0x%x', $n ) )
9637 return @bits ? join( '|', @bits ) : 0;
9644 Rerun the current session to:
9646 rerun current position
9648 rerun 4 command number 4
9650 rerun -4 current command minus 4 (go back 4 steps)
9652 Whether this always makes sense, in the current context is unknowable, and is
9653 in part left as a useful exercise for the reader. This sub returns the
9654 appropriate arguments to rerun the current session.
9661 pop(@truehist); # strim
9662 unless (defined $truehist[$i]) {
9663 print "Unable to return to non-existent command: $i\n";
9665 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
9666 my @temp = @truehist; # store
9667 push(@DB::typeahead, @truehist); # saved
9668 @truehist = @hist = (); # flush
9669 @args = restart(); # setup
9670 get_list("PERLDB_HIST"); # clean
9671 set_list("PERLDB_HIST", @temp); # reset
9678 Restarting the debugger is a complex operation that occurs in several phases.
9679 First, we try to reconstruct the command line that was used to invoke Perl
9685 # I may not be able to resurrect you, but here goes ...
9687 "Warning: some settings and command-line options may be lost!\n";
9688 my ( @script, @flags, $cl );
9690 # If warn was on before, turn it on again.
9691 push @flags, '-w' if $ini_warn;
9693 # Rebuild the -I flags that were on the initial
9696 push @flags, '-I', $_;
9699 # Turn on taint if it was on before.
9700 push @flags, '-T' if ${^TAINT};
9702 # Arrange for setting the old INC:
9703 # Save the current @init_INC in the environment.
9704 set_list( "PERLDB_INC", @ini_INC );
9706 # If this was a perl one-liner, go to the "file"
9707 # corresponding to the one-liner read all the lines
9708 # out of it (except for the first one, which is going
9709 # to be added back on again when 'perl -d' runs: that's
9710 # the 'require perl5db.pl;' line), and add them back on
9711 # to the command line to be executed.
9713 my $lines = *{$main::{'_<-e'}}{ARRAY};
9714 for ( 1 .. $#$lines ) { # The first line is PERL5DB
9715 chomp( $cl = $lines->[$_] );
9716 push @script, '-e', $cl;
9718 } ## end if ($0 eq '-e')
9720 # Otherwise we just reuse the original name we had
9728 After the command line has been reconstructed, the next step is to save
9729 the debugger's status in environment variables. The C<DB::set_list> routine
9730 is used to save aggregate variables (both hashes and arrays); scalars are
9731 just popped into environment variables directly.
9735 # If the terminal supported history, grab it and
9736 # save that in the environment.
9737 set_list( "PERLDB_HIST",
9738 $term->Features->{getHistory}
9742 # Find all the files that were visited during this
9743 # session (i.e., the debugger had magic hashes
9744 # corresponding to them) and stick them in the environment.
9745 my @had_breakpoints = keys %had_breakpoints;
9746 set_list( "PERLDB_VISITED", @had_breakpoints );
9748 # Save the debugger options we chose.
9749 set_list( "PERLDB_OPT", %option );
9750 # set_list( "PERLDB_OPT", options2remember() );
9752 # Save the break-on-loads.
9753 set_list( "PERLDB_ON_LOAD", %break_on_load );
9757 The most complex part of this is the saving of all of the breakpoints. They
9758 can live in an awful lot of places, and we have to go through all of them,
9759 find the breakpoints, and then save them in the appropriate environment
9760 variable via C<DB::set_list>.
9764 # Go through all the breakpoints and make sure they're
9767 for ( 0 .. $#had_breakpoints ) {
9769 # We were in this file.
9770 my $file = $had_breakpoints[$_];
9772 # Grab that file's magic line hash.
9773 *dbline = $main::{ '_<' . $file };
9775 # Skip out if it doesn't exist, or if the breakpoint
9776 # is in a postponed file (we'll do postponed ones
9778 next unless %dbline or $postponed_file{$file};
9780 # In an eval. This is a little harder, so we'll
9781 # do more processing on that below.
9782 ( push @hard, $file ), next
9783 if $file =~ /^\(\w*eval/;
9785 # XXX I have no idea what this is doing. Yet.
9787 @add = %{ $postponed_file{$file} }
9788 if $postponed_file{$file};
9790 # Save the list of all the breakpoints for this file.
9791 set_list( "PERLDB_FILE_$_", %dbline, @add );
9793 # Serialize the extra data %breakpoints_data hash.
9795 set_list( "PERLDB_FILE_ENABLED_$_",
9796 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 }
9797 sort { $a <=> $b } keys(%dbline)
9799 } ## end for (0 .. $#had_breakpoints)
9801 # The breakpoint was inside an eval. This is a little
9802 # more difficult. XXX and I don't understand it.
9803 foreach my $hard_file (@hard) {
9804 # Get over to the eval in question.
9805 *dbline = $main::{ '_<' . $hard_file };
9806 my $quoted = quotemeta $hard_file;
9808 for my $sub ( keys %sub ) {
9809 if (my ($n1, $n2) = $sub{$sub} =~ /\A$quoted:(\d+)-(\d+)\z/) {
9810 $subs{$sub} = [ $n1, $n2 ];
9815 "No subroutines in $hard_file, ignoring breakpoints.\n";
9818 LINES: foreach my $line ( keys %dbline ) {
9820 # One breakpoint per sub only:
9821 my ( $offset, $found );
9822 SUBS: foreach my $sub ( keys %subs ) {
9824 $subs{$sub}->[1] >= $line # Not after the subroutine
9826 not defined $offset # Not caught
9832 $offset = $line - $subs{$sub}->[0];
9834 $offset = "+$offset";
9837 } ## end if ($subs{$sub}->[1] >=...
9838 } ## end for $sub (keys %subs)
9839 if ( defined $offset ) {
9840 $postponed{$found} =
9841 "break $offset if $dbline{$line}";
9845 ("Breakpoint in ${hard_file}:$line ignored:"
9846 . " after all the subroutines.\n");
9848 } ## end for $line (keys %dbline)
9849 } ## end for (@hard)
9851 # Save the other things that don't need to be
9853 set_list( "PERLDB_POSTPONE", %postponed );
9854 set_list( "PERLDB_PRETYPE", @$pretype );
9855 set_list( "PERLDB_PRE", @$pre );
9856 set_list( "PERLDB_POST", @$post );
9857 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9859 # We are officially restarting.
9860 $ENV{PERLDB_RESTART} = 1;
9862 # We are junking all child debuggers.
9863 delete $ENV{PERLDB_PIDS}; # Restore ini state
9865 # Set this back to the initial pid.
9866 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9870 After all the debugger status has been saved, we take the command we built up
9871 and then return it, so we can C<exec()> it. The debugger will spot the
9872 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9873 from the environment.
9877 # And run Perl again. Add the "-d" flag, all the
9878 # flags we built up, the script (whether a one-liner
9879 # or a file), add on the -emacs flag for a slave editor,
9880 # and then the old arguments.
9882 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9888 =head1 END PROCESSING - THE C<END> BLOCK
9890 Come here at the very end of processing. We want to go into a
9891 loop where we allow the user to enter commands and interact with the
9892 debugger, but we don't want anything else to execute.
9894 First we set the C<$finished> variable, so that some commands that
9895 shouldn't be run after the end of program quit working.
9897 We then figure out whether we're truly done (as in the user entered a C<q>
9898 command, or we finished execution while running nonstop). If we aren't,
9899 we set C<$single> to 1 (causing the debugger to get control again).
9901 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9902 message and returns control to the debugger. Repeat.
9904 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9905 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9906 break, run to completion.).
9911 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9912 $fall_off_end = 1 unless $inhibit_exit;
9914 # Do not stop in at_exit() and destructors on exit:
9915 if ($fall_off_end or $runnonstop) {
9919 DB::fake::at_exit();
9923 =head1 PRE-5.8 COMMANDS
9925 Some of the commands changed function quite a bit in the 5.8 command
9926 realignment, so much so that the old code had to be replaced completely.
9927 Because we wanted to retain the option of being able to go back to the
9928 former command set, we moved the old code off to this section.
9930 There's an awful lot of duplicated code here. We've duplicated the
9931 comments to keep things clear.
9935 Does nothing. Used to I<turn off> commands.
9939 sub cmd_pre580_null {
9944 =head2 Old C<a> command.
9946 This version added actions if you supplied them, and deleted them
9955 # Argument supplied. Add the action.
9956 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9958 # If the line isn't there, use the current line.
9959 my $i = $1 || $line;
9962 # If there is an action ...
9965 # ... but the line isn't breakable, skip it.
9966 if ( $dbline[$i] == 0 ) {
9967 print $OUT "Line $i may not have an action.\n";
9971 # ... and the line is breakable:
9972 # Mark that there's an action in this file.
9973 $had_breakpoints{$filename} |= 2;
9975 # Delete any current action.
9976 $dbline{$i} =~ s/\0[^\0]*//;
9978 # Add the new action, continuing the line as needed.
9979 $dbline{$i} .= "\0" . action($j);
9981 } ## end if (length $j)
9983 # No action supplied.
9986 # Delete the action.
9987 $dbline{$i} =~ s/\0[^\0]*//;
9989 # Mark as having no break or action if nothing's left.
9990 delete $dbline{$i} if $dbline{$i} eq '';
9992 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9993 } ## end sub cmd_pre580_a
9995 =head2 Old C<b> command
10004 my $dbline = shift;
10007 if ( $cmd =~ /^load\b\s*(.*)/ ) {
10013 # b compile|postpone <some sub> [<condition>]
10014 # The interpreter actually traps this one for us; we just put the
10015 # necessary condition in the %postponed hash.
10016 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
10018 # Capture the condition if there is one. Make it true if none.
10019 my $cond = length $3 ? $3 : '1';
10021 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
10022 # if it was 'compile'.
10023 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
10025 # De-Perl4-ify the name - ' separators to ::.
10026 $subname =~ s/\'/::/g;
10028 # Qualify it into the current package unless it's already qualified.
10029 $subname = "${package}::" . $subname
10030 unless $subname =~ /::/;
10032 # Add main if it starts with ::.
10033 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
10035 # Save the break type for this sub.
10036 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
10037 } ## end elsif ($cmd =~ ...
10039 # b <sub name> [<condition>]
10040 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
10042 my $cond = length $2 ? $2 : '1';
10043 cmd_b_sub( $subname, $cond );
10045 # b <line> [<condition>].
10046 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
10047 my $i = $1 || $dbline;
10048 my $cond = length $2 ? $2 : '1';
10049 cmd_b_line( $i, $cond );
10051 } ## end sub cmd_pre580_b
10053 =head2 Old C<D> command.
10055 Delete all breakpoints unconditionally.
10062 if ( $cmd =~ /^\s*$/ ) {
10063 print $OUT "Deleting all breakpoints...\n";
10065 # %had_breakpoints lists every file that had at least one
10066 # breakpoint in it.
10068 for $file ( keys %had_breakpoints ) {
10070 # Switch to the desired file temporarily.
10071 local *dbline = $main::{ '_<' . $file };
10076 # For all lines in this file ...
10077 for my $i (1 .. $max) {
10079 # If there's a breakpoint or action on this line ...
10080 if ( defined $dbline{$i} ) {
10082 # ... remove the breakpoint.
10083 $dbline{$i} =~ s/^[^\0]+//;
10084 if ( $dbline{$i} =~ s/^\0?$// ) {
10086 # Remove the entry altogether if no action is there.
10087 delete $dbline{$i};
10089 } ## end if (defined $dbline{$i...
10090 } ## end for my $i (1 .. $max)
10092 # If, after we turn off the "there were breakpoints in this file"
10093 # bit, the entry in %had_breakpoints for this file is zero,
10094 # we should remove this file from the hash.
10095 if ( not $had_breakpoints{$file} &= ~1 ) {
10096 delete $had_breakpoints{$file};
10098 } ## end for $file (keys %had_breakpoints)
10100 # Kill off all the other breakpoints that are waiting for files that
10101 # haven't been loaded yet.
10103 undef %postponed_file;
10104 undef %break_on_load;
10105 } ## end if ($cmd =~ /^\s*$/)
10106 } ## end sub cmd_pre580_D
10108 =head2 Old C<h> command
10110 Print help. Defaults to printing the long-form help; the 5.8 version
10111 prints the summary by default.
10119 # Print the *right* help, long format.
10120 if ( $cmd =~ /^\s*$/ ) {
10121 print_help($pre580_help);
10124 # 'h h' - explicitly-requested summary.
10125 elsif ( $cmd =~ /^h\s*/ ) {
10126 print_help($pre580_summary);
10129 # Find and print a command's help.
10130 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
10131 my $asked = $1; # for proper errmsg
10132 my $qasked = quotemeta($asked); # for searching
10133 # XXX: finds CR but not <CR>
10137 (?:[IB]<) # Optional markup
10138 $qasked # The command name
10145 ( # The command help:
10147 (?:[IB]<) # Optional markup
10148 $qasked # The command name
10149 ([\s\S]*?) # Lines starting with tabs
10153 ) # Line not starting with space
10154 # (Next command's help)
10158 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
10162 print_help("B<$asked> is not a debugger command.\n");
10164 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
10165 } ## end sub cmd_pre580_h
10167 =head2 Old C<W> command
10169 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
10177 # Delete all watch expressions.
10178 if ( $cmd =~ /^$/ ) {
10180 # No watching is going on.
10183 # Kill all the watch expressions and values.
10184 @to_watch = @old_watch = ();
10187 # Add a watch expression.
10188 elsif ( $cmd =~ /^(.*)/s ) {
10190 # add it to the list to be watched.
10191 push @to_watch, $1;
10193 # Get the current value of the expression.
10194 # Doesn't handle expressions returning list values!
10196 # The &-call is here to ascertain the mutability of @_.
10197 my ($val) = &DB::eval;
10198 $val = ( defined $val ) ? "'$val'" : 'undef';
10201 push @old_watch, $val;
10203 # We're watching stuff.
10206 } ## end elsif ($cmd =~ /^(.*)/s)
10207 } ## end sub cmd_pre580_W
10209 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
10211 The debugger used to have a bunch of nearly-identical code to handle
10212 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
10213 C<cmd_prepost> unify all this into one set of code to handle the
10214 appropriate actions.
10216 =head2 C<cmd_pre590_prepost>
10218 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
10219 do something destructive. In pre 5.8 debuggers, the default action was to
10220 delete all the actions.
10224 sub cmd_pre590_prepost {
10226 my $line = shift || '*';
10227 my $dbline = shift;
10229 return cmd_prepost( $cmd, $line, $dbline );
10230 } ## end sub cmd_pre590_prepost
10232 =head2 C<cmd_prepost>
10234 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
10235 Since the lists of actions are all held in arrays that are pointed to by
10236 references anyway, all we have to do is pick the right array reference and
10237 then use generic code to all, delete, or list actions.
10244 # No action supplied defaults to 'list'.
10245 my $line = shift || '?';
10247 # Figure out what to put in the prompt.
10250 # Make sure we have some array or another to address later.
10251 # This means that if for some reason the tests fail, we won't be
10252 # trying to stash actions or delete them from the wrong place.
10255 # < - Perl code to run before prompt.
10256 if ( $cmd =~ /^\</o ) {
10257 $which = 'pre-perl';
10261 # > - Perl code to run after prompt.
10262 elsif ( $cmd =~ /^\>/o ) {
10263 $which = 'post-perl';
10267 # { - first check for properly-balanced braces.
10268 elsif ( $cmd =~ /^\{/o ) {
10269 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
10271 "$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n";
10274 # Properly balanced. Pre-prompt debugger actions.
10276 $which = 'pre-debugger';
10279 } ## end elsif ( $cmd =~ /^\{/o )
10281 # Did we find something that makes sense?
10283 print $OUT "Confused by command: $cmd\n";
10290 if ( $line =~ /^\s*\?\s*$/o ) {
10293 # Nothing there. Complain.
10294 print $OUT "No $which actions.\n";
10298 # List the actions in the selected list.
10299 print $OUT "$which commands:\n";
10300 foreach my $action (@$aref) {
10301 print $OUT "\t$cmd -- $action\n";
10304 } ## end if ( $line =~ /^\s*\?\s*$/o)
10306 # Might be a delete.
10308 if ( length($cmd) == 1 ) {
10309 if ( $line =~ /^\s*\*\s*$/o ) {
10311 # It's a delete. Get rid of the old actions in the
10314 print $OUT "All $cmd actions cleared.\n";
10318 # Replace all the actions. (This is a <, >, or {).
10319 @$aref = action($line);
10321 } ## end if ( length($cmd) == 1)
10322 elsif ( length($cmd) == 2 ) {
10324 # Add the action to the line. (This is a <<, >>, or {{).
10325 push @$aref, action($line);
10329 # <<<, >>>>, {{{{{{ ... something not a command.
10331 "Confused by strange length of $which command($cmd)...\n";
10333 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
10335 } ## end sub cmd_prepost
10339 Contains the C<at_exit> routine that the debugger uses to issue the
10340 C<Debugged program terminated ...> message after the program completes. See
10341 the C<END> block documentation for more details.
10348 "Debugged program terminated. Use 'q' to quit or 'R' to restart.";
10351 package DB; # Do not trace this 1; below!