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fix debugger y command scope level
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e22ea7cc 1
b570d64b 2=head1 NAME
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be9a9b1d 4perl5db.pl - the perl debugger
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6=head1 SYNOPSIS
7
8 perl -d your_Perl_script
9
10=head1 DESCRIPTION
11
12C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
13you invoke a script with C<perl -d>. This documentation tries to outline the
14structure and services provided by C<perl5db.pl>, and to describe how you
15can use them.
16
17=head1 GENERAL NOTES
18
19The debugger can look pretty forbidding to many Perl programmers. There are
20a number of reasons for this, many stemming out of the debugger's history.
21
22When the debugger was first written, Perl didn't have a lot of its nicer
23features - no references, no lexical variables, no closures, no object-oriented
24programming. So a lot of the things one would normally have done using such
b570d64b 25features was done using global variables, globs and the C<local()> operator
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26in creative ways.
27
28Some of these have survived into the current debugger; a few of the more
29interesting and still-useful idioms are noted in this section, along with notes
30on the comments themselves.
31
32=head2 Why not use more lexicals?
33
34Experienced Perl programmers will note that the debugger code tends to use
35mostly package globals rather than lexically-scoped variables. This is done
36to allow a significant amount of control of the debugger from outside the
b570d64b 37debugger itself.
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38
39Unfortunately, though the variables are accessible, they're not well
40documented, so it's generally been a decision that hasn't made a lot of
41difference to most users. Where appropriate, comments have been added to
42make variables more accessible and usable, with the understanding that these
be9a9b1d 43I<are> debugger internals, and are therefore subject to change. Future
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44development should probably attempt to replace the globals with a well-defined
45API, but for now, the variables are what we've got.
46
47=head2 Automated variable stacking via C<local()>
48
b570d64b 49As you may recall from reading C<perlfunc>, the C<local()> operator makes a
69893cff 50temporary copy of a variable in the current scope. When the scope ends, the
b570d64b 51old copy is restored. This is often used in the debugger to handle the
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52automatic stacking of variables during recursive calls:
53
54 sub foo {
55 local $some_global++;
56
57 # Do some stuff, then ...
58 return;
59 }
60
61What happens is that on entry to the subroutine, C<$some_global> is localized,
b570d64b 62then altered. When the subroutine returns, Perl automatically undoes the
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63localization, restoring the previous value. Voila, automatic stack management.
64
b570d64b 65The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
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66which lets the debugger get control inside of C<eval>'ed code. The debugger
67localizes a saved copy of C<$@> inside the subroutine, which allows it to
68keep C<$@> safe until it C<DB::eval> returns, at which point the previous
b570d64b 69value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
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70track of C<$@> inside C<eval>s which C<eval> other C<eval's>.
71
72In any case, watch for this pattern. It occurs fairly often.
73
74=head2 The C<^> trick
75
b570d64b 76This is used to cleverly reverse the sense of a logical test depending on
69893cff 77the value of an auxiliary variable. For instance, the debugger's C<S>
b570d64b 78(search for subroutines by pattern) allows you to negate the pattern
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79like this:
80
81 # Find all non-'foo' subs:
b570d64b 82 S !/foo/
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83
84Boolean algebra states that the truth table for XOR looks like this:
85
86=over 4
87
b570d64b 88=item * 0 ^ 0 = 0
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89
90(! not present and no match) --> false, don't print
91
b570d64b 92=item * 0 ^ 1 = 1
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93
94(! not present and matches) --> true, print
95
b570d64b 96=item * 1 ^ 0 = 1
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97
98(! present and no match) --> true, print
99
b570d64b 100=item * 1 ^ 1 = 0
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101
102(! present and matches) --> false, don't print
103
104=back
105
106As you can see, the first pair applies when C<!> isn't supplied, and
be9a9b1d 107the second pair applies when it is. The XOR simply allows us to
b570d64b 108compact a more complicated if-then-elseif-else into a more elegant
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109(but perhaps overly clever) single test. After all, it needed this
110explanation...
111
112=head2 FLAGS, FLAGS, FLAGS
113
114There is a certain C programming legacy in the debugger. Some variables,
be9a9b1d 115such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed
69893cff 116of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
b570d64b 117of state to be stored independently in a single scalar.
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118
119A test like
120
121 if ($scalar & 4) ...
122
b570d64b 123is checking to see if the appropriate bit is on. Since each bit can be
69893cff 124"addressed" independently in this way, C<$scalar> is acting sort of like
b570d64b 125an array of bits. Obviously, since the contents of C<$scalar> are just a
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126bit-pattern, we can save and restore it easily (it will just look like
127a number).
128
129The problem, is of course, that this tends to leave magic numbers scattered
b570d64b 130all over your program whenever a bit is set, cleared, or checked. So why do
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131it?
132
133=over 4
134
be9a9b1d 135=item *
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be9a9b1d 137First, doing an arithmetical or bitwise operation on a scalar is
69893cff 138just about the fastest thing you can do in Perl: C<use constant> actually
be9a9b1d 139creates a subroutine call, and array and hash lookups are much slower. Is
b570d64b 140this over-optimization at the expense of readability? Possibly, but the
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141debugger accesses these variables a I<lot>. Any rewrite of the code will
142probably have to benchmark alternate implementations and see which is the
b570d64b 143best balance of readability and speed, and then document how it actually
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144works.
145
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146=item *
147
b570d64b 148Second, it's very easy to serialize a scalar number. This is done in
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149the restart code; the debugger state variables are saved in C<%ENV> and then
150restored when the debugger is restarted. Having them be just numbers makes
b570d64b 151this trivial.
69893cff 152
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153=item *
154
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155Third, some of these variables are being shared with the Perl core
156smack in the middle of the interpreter's execution loop. It's much faster for
157a C program (like the interpreter) to check a bit in a scalar than to access
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158several different variables (or a Perl array).
159
160=back
161
162=head2 What are those C<XXX> comments for?
163
164Any comment containing C<XXX> means that the comment is either somewhat
b570d64b 165speculative - it's not exactly clear what a given variable or chunk of
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166code is doing, or that it is incomplete - the basics may be clear, but the
167subtleties are not completely documented.
168
169Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
170
b570d64b 171=head1 DATA STRUCTURES MAINTAINED BY CORE
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172
173There are a number of special data structures provided to the debugger by
174the Perl interpreter.
175
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176The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline>
177via glob assignment) contains the text from C<$filename>, with each
178element corresponding to a single line of C<$filename>. Additionally,
179breakable lines will be dualvars with the numeric component being the
180memory address of a COP node. Non-breakable lines are dualvar to 0.
69893cff 181
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182The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
183assignment) contains breakpoints and actions. The keys are line numbers;
184you can set individual values, but not the whole hash. The Perl interpreter
69893cff 185uses this hash to determine where breakpoints have been set. Any true value is
be9a9b1d 186considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
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187Values are magical in numeric context: 1 if the line is breakable, 0 if not.
188
da052516 189The scalar C<${"_<$filename"}> simply contains the string C<$filename>.
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190This is also the case for evaluated strings that contain subroutines, or
191which are currently being executed. The $filename for C<eval>ed strings looks
d24ca0c5 192like C<(eval 34).
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193
194=head1 DEBUGGER STARTUP
195
196When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
197non-interactive sessions, C<.perldb> for interactive ones) that can set a number
198of options. In addition, this file may define a subroutine C<&afterinit>
b570d64b 199that will be executed (in the debugger's context) after the debugger has
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200initialized itself.
201
b570d64b 202Next, it checks the C<PERLDB_OPTS> environment variable and treats its
be9a9b1d 203contents as the argument of a C<o> command in the debugger.
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204
205=head2 STARTUP-ONLY OPTIONS
206
207The following options can only be specified at startup.
208To set them in your rcfile, add a call to
209C<&parse_options("optionName=new_value")>.
210
211=over 4
212
b570d64b 213=item * TTY
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214
215the TTY to use for debugging i/o.
216
b570d64b 217=item * noTTY
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218
219if set, goes in NonStop mode. On interrupt, if TTY is not set,
b0e77abc 220uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
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221Term::Rendezvous. Current variant is to have the name of TTY in this
222file.
223
b570d64b 224=item * ReadLine
69893cff 225
5561b870 226if false, a dummy ReadLine is used, so you can debug
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227ReadLine applications.
228
b570d64b 229=item * NonStop
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230
231if true, no i/o is performed until interrupt.
232
b570d64b 233=item * LineInfo
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234
235file or pipe to print line number info to. If it is a
236pipe, a short "emacs like" message is used.
237
b570d64b 238=item * RemotePort
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239
240host:port to connect to on remote host for remote debugging.
241
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242=item * HistFile
243
244file to store session history to. There is no default and so no
245history file is written unless this variable is explicitly set.
246
247=item * HistSize
248
249number of commands to store to the file specified in C<HistFile>.
250Default is 100.
251
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252=back
253
254=head3 SAMPLE RCFILE
255
256 &parse_options("NonStop=1 LineInfo=db.out");
257 sub afterinit { $trace = 1; }
258
259The script will run without human intervention, putting trace
260information into C<db.out>. (If you interrupt it, you had better
be9a9b1d 261reset C<LineInfo> to something I<interactive>!)
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262
263=head1 INTERNALS DESCRIPTION
264
265=head2 DEBUGGER INTERFACE VARIABLES
266
267Perl supplies the values for C<%sub>. It effectively inserts
be9a9b1d 268a C<&DB::DB();> in front of each place that can have a
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269breakpoint. At each subroutine call, it calls C<&DB::sub> with
270C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
271{require 'perl5db.pl'}> before the first line.
272
273After each C<require>d file is compiled, but before it is executed, a
274call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
275is the expanded name of the C<require>d file (as found via C<%INC>).
276
277=head3 IMPORTANT INTERNAL VARIABLES
278
279=head4 C<$CreateTTY>
280
281Used to control when the debugger will attempt to acquire another TTY to be
b570d64b 282used for input.
69893cff 283
b570d64b 284=over
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285
286=item * 1 - on C<fork()>
287
288=item * 2 - debugger is started inside debugger
289
290=item * 4 - on startup
291
292=back
293
294=head4 C<$doret>
295
296The value -2 indicates that no return value should be printed.
297Any other positive value causes C<DB::sub> to print return values.
298
299=head4 C<$evalarg>
300
301The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
302contents of C<@_> when C<DB::eval> is called.
303
304=head4 C<$frame>
305
306Determines what messages (if any) will get printed when a subroutine (or eval)
b570d64b 307is entered or exited.
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308
309=over 4
310
311=item * 0 - No enter/exit messages
312
be9a9b1d 313=item * 1 - Print I<entering> messages on subroutine entry
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314
315=item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
316
be9a9b1d 317=item * 4 - Extended messages: C<< <in|out> I<context>=I<fully-qualified sub name> from I<file>:I<line> >>. If no other flag is on, acts like 1+4.
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318
319=item * 8 - Adds parameter information to messages, and overloaded stringify and tied FETCH is enabled on the printed arguments. Ignored if C<4> is not on.
320
7e3426ea 321=item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is not on.
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322
323=back
324
be9a9b1d 325To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
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326The debugger internally juggles the value of C<$frame> during execution to
327protect external modules that the debugger uses from getting traced.
328
329=head4 C<$level>
330
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331Tracks current debugger nesting level. Used to figure out how many
332C<E<lt>E<gt>> pairs to surround the line number with when the debugger
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333outputs a prompt. Also used to help determine if the program has finished
334during command parsing.
335
336=head4 C<$onetimeDump>
337
338Controls what (if anything) C<DB::eval()> will print after evaluating an
339expression.
340
341=over 4
342
343=item * C<undef> - don't print anything
344
345=item * C<dump> - use C<dumpvar.pl> to display the value returned
346
347=item * C<methods> - print the methods callable on the first item returned
348
349=back
350
351=head4 C<$onetimeDumpDepth>
352
be9a9b1d 353Controls how far down C<dumpvar.pl> will go before printing C<...> while
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354dumping a structure. Numeric. If C<undef>, print all levels.
355
356=head4 C<$signal>
357
358Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
359which is called before every statement, checks this and puts the user into
360command mode if it finds C<$signal> set to a true value.
361
362=head4 C<$single>
363
364Controls behavior during single-stepping. Stacked in C<@stack> on entry to
365each subroutine; popped again at the end of each subroutine.
366
b570d64b 367=over 4
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368
369=item * 0 - run continuously.
370
be9a9b1d 371=item * 1 - single-step, go into subs. The C<s> command.
69893cff 372
be9a9b1d 373=item * 2 - single-step, don't go into subs. The C<n> command.
69893cff 374
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375=item * 4 - print current sub depth (turned on to force this when C<too much
376recursion> occurs.
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377
378=back
379
380=head4 C<$trace>
381
b570d64b 382Controls the output of trace information.
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383
384=over 4
385
386=item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
387
388=item * 2 - watch expressions are active
389
390=item * 4 - user defined a C<watchfunction()> in C<afterinit()>
391
392=back
393
394=head4 C<$slave_editor>
395
3961 if C<LINEINFO> was directed to a pipe; 0 otherwise.
397
398=head4 C<@cmdfhs>
399
400Stack of filehandles that C<DB::readline()> will read commands from.
401Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
402
403=head4 C<@dbline>
404
b570d64b 405Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
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406supplied by the Perl interpreter to the debugger. Contains the source.
407
408=head4 C<@old_watch>
409
410Previous values of watch expressions. First set when the expression is
411entered; reset whenever the watch expression changes.
412
413=head4 C<@saved>
414
415Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
416so that the debugger can substitute safe values while it's running, and
417restore them when it returns control.
418
419=head4 C<@stack>
420
421Saves the current value of C<$single> on entry to a subroutine.
422Manipulated by the C<c> command to turn off tracing in all subs above the
423current one.
424
425=head4 C<@to_watch>
426
427The 'watch' expressions: to be evaluated before each line is executed.
428
429=head4 C<@typeahead>
430
431The typeahead buffer, used by C<DB::readline>.
432
433=head4 C<%alias>
434
435Command aliases. Stored as character strings to be substituted for a command
436entered.
437
438=head4 C<%break_on_load>
439
440Keys are file names, values are 1 (break when this file is loaded) or undef
441(don't break when it is loaded).
442
443=head4 C<%dbline>
444
be9a9b1d 445Keys are line numbers, values are C<condition\0action>. If used in numeric
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446context, values are 0 if not breakable, 1 if breakable, no matter what is
447in the actual hash entry.
448
449=head4 C<%had_breakpoints>
450
451Keys are file names; values are bitfields:
452
b570d64b 453=over 4
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454
455=item * 1 - file has a breakpoint in it.
456
457=item * 2 - file has an action in it.
458
459=back
460
461A zero or undefined value means this file has neither.
462
463=head4 C<%option>
464
465Stores the debugger options. These are character string values.
466
467=head4 C<%postponed>
468
469Saves breakpoints for code that hasn't been compiled yet.
470Keys are subroutine names, values are:
471
472=over 4
473
be9a9b1d 474=item * C<compile> - break when this sub is compiled
69893cff 475
be9a9b1d 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.
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477
478=back
479
480=head4 C<%postponed_file>
481
482This hash keeps track of breakpoints that need to be set for files that have
483not yet been compiled. Keys are filenames; values are references to hashes.
484Each of these hashes is keyed by line number, and its values are breakpoint
be9a9b1d 485definitions (C<condition\0action>).
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486
487=head1 DEBUGGER INITIALIZATION
488
489The debugger's initialization actually jumps all over the place inside this
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490package. This is because there are several BEGIN blocks (which of course
491execute immediately) spread through the code. Why is that?
69893cff 492
b570d64b 493The debugger needs to be able to change some things and set some things up
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494before the debugger code is compiled; most notably, the C<$deep> variable that
495C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
496debugger has to turn off warnings while the debugger code is compiled, but then
497restore them to their original setting before the program being debugged begins
498executing.
499
500The first C<BEGIN> block simply turns off warnings by saving the current
501setting of C<$^W> and then setting it to zero. The second one initializes
502the debugger variables that are needed before the debugger begins executing.
b570d64b 503The third one puts C<$^X> back to its former value.
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504
505We'll detail the second C<BEGIN> block later; just remember that if you need
506to initialize something before the debugger starts really executing, that's
507where it has to go.
508
509=cut
510
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511package DB;
512
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513use strict;
514
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515use Cwd ();
516
517my $_initial_cwd;
518
2dbd01ad 519BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
9eba6a4e 520
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521BEGIN {
522 require feature;
523 $^V =~ /^v(\d+\.\d+)/;
524 feature->import(":$1");
c59f1e04 525 $_initial_cwd = Cwd::getcwd();
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526}
527
54d04a52 528# Debugger for Perl 5.00x; perl5db.pl patch level:
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529use vars qw($VERSION $header);
530
496f5ba5 531$VERSION = '1.46';
69893cff 532
e22ea7cc 533$header = "perl5db.pl version $VERSION";
d338d6fe 534
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535=head1 DEBUGGER ROUTINES
536
537=head2 C<DB::eval()>
538
539This function replaces straight C<eval()> inside the debugger; it simplifies
540the process of evaluating code in the user's context.
541
b570d64b 542The code to be evaluated is passed via the package global variable
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543C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
544
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545Before we do the C<eval()>, we preserve the current settings of C<$trace>,
546C<$single>, C<$^D> and C<$usercontext>. The latter contains the
547preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
548user's current package, grabbed when C<DB::DB> got control. This causes the
549proper context to be used when the eval is actually done. Afterward, we
550restore C<$trace>, C<$single>, and C<$^D>.
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551
552Next we need to handle C<$@> without getting confused. We save C<$@> in a
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553local lexical, localize C<$saved[0]> (which is where C<save()> will put
554C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
69893cff 555C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
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556considered sane by the debugger. If there was an C<eval()> error, we print
557it on the debugger's output. If C<$onetimedump> is defined, we call
558C<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
560but not print the result - handy if you want to do something else with it
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561(the "watch expressions" code does this to get the value of the watch
562expression but not show it unless it matters).
563
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564In any case, we then return the list of output from C<eval> to the caller,
565and unwinding restores the former version of C<$@> in C<@saved> as well
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566(the localization of C<$saved[0]> goes away at the end of this scope).
567
568=head3 Parameters and variables influencing execution of DB::eval()
569
570C<DB::eval> isn't parameterized in the standard way; this is to keep the
571debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
b570d64b 572The variables listed below influence C<DB::eval()>'s execution directly.
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573
574=over 4
575
576=item C<$evalarg> - the thing to actually be eval'ed
577
be9a9b1d 578=item C<$trace> - Current state of execution tracing
69893cff 579
be9a9b1d 580=item C<$single> - Current state of single-stepping
69893cff 581
b570d64b 582=item C<$onetimeDump> - what is to be displayed after the evaluation
69893cff
RGS
583
584=item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
585
586=back
587
588The following variables are altered by C<DB::eval()> during its execution. They
b570d64b 589are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
69893cff
RGS
590
591=over 4
592
593=item C<@res> - used to capture output from actual C<eval>.
594
595=item C<$otrace> - saved value of C<$trace>.
596
b570d64b 597=item C<$osingle> - saved value of C<$single>.
69893cff
RGS
598
599=item C<$od> - saved value of C<$^D>.
600
601=item C<$saved[0]> - saved value of C<$@>.
602
b570d64b 603=item $\ - for output of C<$@> if there is an evaluation error.
69893cff
RGS
604
605=back
606
607=head3 The problem of lexicals
608
609The context of C<DB::eval()> presents us with some problems. Obviously,
610we want to be 'sandboxed' away from the debugger's internals when we do
611the eval, but we need some way to control how punctuation variables and
b570d64b 612debugger globals are used.
69893cff
RGS
613
614We can't use local, because the code inside C<DB::eval> can see localized
615variables; and we can't use C<my> either for the same reason. The code
616in this routine compromises and uses C<my>.
617
618After this routine is over, we don't have user code executing in the debugger's
619context, so we can use C<my> freely.
620
621=cut
622
623############################################## Begin lexical danger zone
624
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.
628#
629# Fiddling with the debugger's context could be Bad. We insulate things as
630# much as we can.
631
6b24a4b7
SF
632use vars qw(
633 @args
634 %break_on_load
6b24a4b7
SF
635 $CommandSet
636 $CreateTTY
637 $DBGR
638 @dbline
639 $dbline
640 %dbline
641 $dieLevel
6b24a4b7 642 $filename
6b24a4b7
SF
643 $histfile
644 $histsize
6b24a4b7
SF
645 $IN
646 $inhibit_exit
647 @ini_INC
648 $ini_warn
6b24a4b7
SF
649 $maxtrace
650 $od
6b24a4b7
SF
651 @options
652 $osingle
653 $otrace
6b24a4b7
SF
654 $pager
655 $post
656 %postponed
657 $prc
658 $pre
659 $pretype
660 $psh
661 @RememberOnROptions
662 $remoteport
663 @res
664 $rl
665 @saved
6b24a4b7 666 $signalLevel
6b24a4b7 667 $sub
6b24a4b7 668 $term
6b24a4b7
SF
669 $usercontext
670 $warnLevel
6b24a4b7
SF
671);
672
0b83f3d9 673our (
2ef1dcdb 674 @cmdfhs,
0b83f3d9
SF
675 $evalarg,
676 $frame,
0664c09a 677 $hist,
0b83f3d9
SF
678 $ImmediateStop,
679 $line,
680 $onetimeDump,
b8d11fe0 681 $onetimedumpDepth,
1ce985d2 682 %option,
0b83f3d9 683 $OUT,
1ce985d2 684 $packname,
0b83f3d9
SF
685 $signal,
686 $single,
d1450c23 687 $start,
9d0b71b3
SF
688 %sub,
689 $subname,
0b83f3d9 690 $trace,
d1450c23 691 $window,
18b5b545 692);
931ac036 693
6b24a4b7
SF
694# Used to save @ARGV and extract any debugger-related flags.
695use vars qw(@ARGS);
696
697# Used to prevent multiple entries to diesignal()
698# (if for instance diesignal() itself dies)
699use vars qw($panic);
700
701# Used to prevent the debugger from running nonstop
702# after a restart
ebd0282e 703our ($second_time);
6b24a4b7
SF
704
705sub _calc_usercontext {
706 my ($package) = @_;
707
708 # Cancel strict completely for the evaluated code, so the code
709 # the user evaluates won't be affected by it. (Shlomi Fish)
22fc883d 710 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
6b24a4b7
SF
711 . "package $package;"; # this won't let them modify, alas
712}
713
c1051fcf 714sub eval {
69893cff 715
c1051fcf 716 # 'my' would make it visible from user code
e22ea7cc 717 # but so does local! --tchrist
69893cff 718 # Remember: this localizes @DB::res, not @main::res.
c1051fcf
IZ
719 local @res;
720 {
e22ea7cc
RF
721
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
69893cff
RGS
725 # package globals (and any 'my' variables in this containing scope)
726 # inside the eval(), and we want to try to stay safe.
e22ea7cc 727 local $otrace = $trace;
69893cff
RGS
728 local $osingle = $single;
729 local $od = $^D;
730
731 # Untaint the incoming eval() argument.
732 { ($evalarg) = $evalarg =~ /(.*)/s; }
733
e22ea7cc 734 # $usercontext built in DB::DB near the comment
69893cff
RGS
735 # "set up the context for DB::eval ..."
736 # Evaluate and save any results.
e22ea7cc 737 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
69893cff
RGS
738
739 # Restore those old values.
740 $trace = $otrace;
741 $single = $osingle;
742 $^D = $od;
c1051fcf 743 }
69893cff
RGS
744
745 # Save the current value of $@, and preserve it in the debugger's copy
746 # of the saved precious globals.
c1051fcf 747 my $at = $@;
69893cff
RGS
748
749 # Since we're only saving $@, we only have to localize the array element
750 # that it will be stored in.
e22ea7cc 751 local $saved[0]; # Preserve the old value of $@
e3d167f6 752 eval { &DB::save };
69893cff
RGS
753
754 # Now see whether we need to report an error back to the user.
c1051fcf 755 if ($at) {
69893cff
RGS
756 local $\ = '';
757 print $OUT $at;
758 }
759
760 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
761 # are package globals.
762 elsif ($onetimeDump) {
e22ea7cc
RF
763 if ( $onetimeDump eq 'dump' ) {
764 local $option{dumpDepth} = $onetimedumpDepth
765 if defined $onetimedumpDepth;
766 dumpit( $OUT, \@res );
767 }
768 elsif ( $onetimeDump eq 'methods' ) {
769 methods( $res[0] );
770 }
69893cff 771 } ## end elsif ($onetimeDump)
c1051fcf 772 @res;
69893cff
RGS
773} ## end sub eval
774
775############################################## End lexical danger zone
c1051fcf 776
e22ea7cc
RF
777# After this point it is safe to introduce lexicals.
778# The code being debugged will be executing in its own context, and
69893cff 779# can't see the inside of the debugger.
d338d6fe 780#
e22ea7cc 781# However, one should not overdo it: leave as much control from outside as
69893cff
RGS
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.
784
d338d6fe
PP
785# This file is automatically included if you do perl -d.
786# It's probably not useful to include this yourself.
787#
e22ea7cc 788# Before venturing further into these twisty passages, it is
2f7e9187
MS
789# wise to read the perldebguts man page or risk the ire of dragons.
790#
69893cff
RGS
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.)
795
d338d6fe 796# Note that no subroutine call is possible until &DB::sub is defined
36477c24 797# (for subroutines defined outside of the package DB). In fact the same is
d338d6fe 798# true if $deep is not defined.
055fd3a9
GS
799
800# Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
055fd3a9
GS
801
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 ;-)
6fae1ad7 806########################################################################
d338d6fe 807
69893cff
RGS
808=head1 DEBUGGER INITIALIZATION
809
810The debugger starts up in phases.
811
812=head2 BASIC SETUP
813
814First, it initializes the environment it wants to run in: turning off
815warnings during its own compilation, defining variables which it will need
816to avoid warnings later, setting itself up to not exit when the program
817terminates, and defaulting to printing return values for the C<r> command.
818
819=cut
820
eda6e075 821# Needed for the statement after exec():
69893cff
RGS
822#
823# This BEGIN block is simply used to switch off warnings during debugger
98dc9551 824# compilation. Probably it would be better practice to fix the warnings,
69893cff 825# but this is how it's done at the moment.
eda6e075 826
e22ea7cc
RF
827BEGIN {
828 $ini_warn = $^W;
829 $^W = 0;
830} # Switch compilation warnings off until another BEGIN.
d12a4851 831
69893cff
RGS
832local ($^W) = 0; # Switch run-time warnings off during init.
833
2cbb2ee1
RGS
834=head2 THREADS SUPPORT
835
836If we are running under a threaded Perl, we require threads and threads::shared
837if the environment variable C<PERL5DB_THREADED> is set, to enable proper
838threaded debugger control. C<-dt> can also be used to set this.
839
840Each new thread will be announced and the debugger prompt will always inform
841you of each new thread created. It will also indicate the thread id in which
842we are currently running within the prompt like this:
843
2dbd01ad 844 [tid] DB<$i>
2cbb2ee1
RGS
845
846Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
847command prompt. The prompt will show: C<[0]> when running under threads, but
848not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
849
850While running under threads, when you set or delete a breakpoint (etc.), this
b570d64b 851will apply to all threads, not just the currently running one. When you are
2cbb2ee1
RGS
852in a currently executing thread, you will stay there until it completes. With
853the current implementation it is not currently possible to hop from one thread
854to another.
855
856The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
857
858Note that threading support was built into the debugger as of Perl version
859C<5.8.6> and debugger version C<1.2.8>.
860
861=cut
862
863BEGIN {
2dbd01ad
SF
864 # ensure we can share our non-threaded variables or no-op
865 if ($ENV{PERL5DB_THREADED}) {
866 require threads;
867 require threads::shared;
868 import threads::shared qw(share);
869 $DBGR;
870 share(\$DBGR);
871 lock($DBGR);
872 print "Threads support enabled\n";
873 } else {
cde405a6 874 *share = sub(\[$@%]) {};
2dbd01ad 875 }
2cbb2ee1
RGS
876}
877
2218c045
SF
878# These variables control the execution of 'dumpvar.pl'.
879{
880 package dumpvar;
881 use vars qw(
882 $hashDepth
883 $arrayDepth
884 $dumpDBFiles
885 $dumpPackages
886 $quoteHighBit
887 $printUndef
888 $globPrint
889 $usageOnly
890 );
891}
69893cff 892
2218c045
SF
893# used to control die() reporting in diesignal()
894{
895 package Carp;
896 use vars qw($CarpLevel);
897}
d338d6fe 898
422c59bf 899# without threads, $filename is not defined until DB::DB is called
cde405a6 900share($main::{'_<'.$filename}) if defined $filename;
2cbb2ee1 901
54d04a52 902# Command-line + PERLLIB:
69893cff 903# Save the contents of @INC before they are modified elsewhere.
54d04a52
IZ
904@ini_INC = @INC;
905
69893cff
RGS
906# This was an attempt to clear out the previous values of various
907# trapped errors. Apparently it didn't help. XXX More info needed!
d338d6fe
PP
908# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
909
69893cff
RGS
910# We set these variables to safe values. We don't want to blindly turn
911# off warnings, because other packages may still want them.
e22ea7cc
RF
912$trace = $signal = $single = 0; # Uninitialized warning suppression
913 # (local $^W cannot help - other packages!).
69893cff
RGS
914
915# Default to not exiting when program finishes; print the return
916# value when the 'r' command is used to return from a subroutine.
55497cff 917$inhibit_exit = $option{PrintRet} = 1;
d338d6fe 918
6b24a4b7
SF
919use vars qw($trace_to_depth);
920
5e2b42dd
SF
921# Default to 1E9 so it won't be limited to a certain recursion depth.
922$trace_to_depth = 1E9;
bdba49ad 923
69893cff
RGS
924=head1 OPTION PROCESSING
925
b570d64b
SF
926The debugger's options are actually spread out over the debugger itself and
927C<dumpvar.pl>; some of these are variables to be set, while others are
69893cff
RGS
928subs to be called with a value. To try to make this a little easier to
929manage, the debugger uses a few data structures to define what options
930are legal and how they are to be processed.
931
932First, the C<@options> array defines the I<names> of all the options that
933are to be accepted.
934
935=cut
936
937@options = qw(
5561b870 938 CommandSet HistFile HistSize
e22ea7cc
RF
939 hashDepth arrayDepth dumpDepth
940 DumpDBFiles DumpPackages DumpReused
941 compactDump veryCompact quote
942 HighBit undefPrint globPrint
943 PrintRet UsageOnly frame
944 AutoTrace TTY noTTY
945 ReadLine NonStop LineInfo
946 maxTraceLen recallCommand ShellBang
947 pager tkRunning ornaments
948 signalLevel warnLevel dieLevel
949 inhibit_exit ImmediateStop bareStringify
950 CreateTTY RemotePort windowSize
584420f0 951 DollarCaretP
e22ea7cc 952);
d12a4851 953
584420f0 954@RememberOnROptions = qw(DollarCaretP);
d12a4851 955
69893cff
RGS
956=pod
957
958Second, C<optionVars> lists the variables that each option uses to save its
959state.
960
961=cut
962
6b24a4b7
SF
963use vars qw(%optionVars);
964
69893cff 965%optionVars = (
e22ea7cc
RF
966 hashDepth => \$dumpvar::hashDepth,
967 arrayDepth => \$dumpvar::arrayDepth,
968 CommandSet => \$CommandSet,
969 DumpDBFiles => \$dumpvar::dumpDBFiles,
970 DumpPackages => \$dumpvar::dumpPackages,
971 DumpReused => \$dumpvar::dumpReused,
972 HighBit => \$dumpvar::quoteHighBit,
973 undefPrint => \$dumpvar::printUndef,
974 globPrint => \$dumpvar::globPrint,
975 UsageOnly => \$dumpvar::usageOnly,
976 CreateTTY => \$CreateTTY,
977 bareStringify => \$dumpvar::bareStringify,
978 frame => \$frame,
979 AutoTrace => \$trace,
980 inhibit_exit => \$inhibit_exit,
981 maxTraceLen => \$maxtrace,
982 ImmediateStop => \$ImmediateStop,
983 RemotePort => \$remoteport,
984 windowSize => \$window,
5561b870
AK
985 HistFile => \$histfile,
986 HistSize => \$histsize,
69893cff
RGS
987);
988
989=pod
990
991Third, C<%optionAction> defines the subroutine to be called to process each
992option.
993
b570d64b 994=cut
69893cff 995
6b24a4b7
SF
996use vars qw(%optionAction);
997
69893cff
RGS
998%optionAction = (
999 compactDump => \&dumpvar::compactDump,
1000 veryCompact => \&dumpvar::veryCompact,
1001 quote => \&dumpvar::quote,
1002 TTY => \&TTY,
1003 noTTY => \&noTTY,
1004 ReadLine => \&ReadLine,
1005 NonStop => \&NonStop,
1006 LineInfo => \&LineInfo,
1007 recallCommand => \&recallCommand,
1008 ShellBang => \&shellBang,
1009 pager => \&pager,
1010 signalLevel => \&signalLevel,
1011 warnLevel => \&warnLevel,
1012 dieLevel => \&dieLevel,
1013 tkRunning => \&tkRunning,
1014 ornaments => \&ornaments,
1015 RemotePort => \&RemotePort,
1016 DollarCaretP => \&DollarCaretP,
d12a4851
JH
1017);
1018
69893cff
RGS
1019=pod
1020
1021Last, the C<%optionRequire> notes modules that must be C<require>d if an
1022option is used.
1023
1024=cut
d338d6fe 1025
69893cff
RGS
1026# Note that this list is not complete: several options not listed here
1027# actually require that dumpvar.pl be loaded for them to work, but are
1028# not in the table. A subsequent patch will correct this problem; for
1029# the moment, we're just recommenting, and we are NOT going to change
1030# function.
6b24a4b7
SF
1031use vars qw(%optionRequire);
1032
eda6e075 1033%optionRequire = (
69893cff
RGS
1034 compactDump => 'dumpvar.pl',
1035 veryCompact => 'dumpvar.pl',
1036 quote => 'dumpvar.pl',
e22ea7cc 1037);
69893cff
RGS
1038
1039=pod
1040
1041There are a number of initialization-related variables which can be set
1042by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1043variable. These are:
1044
1045=over 4
1046
1047=item C<$rl> - readline control XXX needs more explanation
1048
1049=item C<$warnLevel> - whether or not debugger takes over warning handling
1050
1051=item C<$dieLevel> - whether or not debugger takes over die handling
1052
1053=item C<$signalLevel> - whether or not debugger takes over signal handling
1054
1055=item C<$pre> - preprompt actions (array reference)
1056
1057=item C<$post> - postprompt actions (array reference)
1058
1059=item C<$pretype>
1060
1061=item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1062
1063=item C<$CommandSet> - which command set to use (defaults to new, documented set)
1064
1065=back
1066
1067=cut
d338d6fe
PP
1068
1069# These guys may be defined in $ENV{PERL5DB} :
69893cff
RGS
1070$rl = 1 unless defined $rl;
1071$warnLevel = 1 unless defined $warnLevel;
1072$dieLevel = 1 unless defined $dieLevel;
1073$signalLevel = 1 unless defined $signalLevel;
1074$pre = [] unless defined $pre;
1075$post = [] unless defined $post;
1076$pretype = [] unless defined $pretype;
1077$CreateTTY = 3 unless defined $CreateTTY;
1078$CommandSet = '580' unless defined $CommandSet;
1079
2cbb2ee1
RGS
1080share($rl);
1081share($warnLevel);
1082share($dieLevel);
1083share($signalLevel);
1084share($pre);
1085share($post);
1086share($pretype);
1087share($rl);
1088share($CreateTTY);
1089share($CommandSet);
1090
69893cff
RGS
1091=pod
1092
1093The default C<die>, C<warn>, and C<signal> handlers are set up.
1094
1095=cut
055fd3a9 1096
d338d6fe
PP
1097warnLevel($warnLevel);
1098dieLevel($dieLevel);
1099signalLevel($signalLevel);
055fd3a9 1100
69893cff
RGS
1101=pod
1102
1103The pager to be used is needed next. We try to get it from the
5561b870 1104environment first. If it's not defined there, we try to find it in
69893cff
RGS
1105the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1106then call the C<pager()> function to save the pager name.
1107
1108=cut
1109
1110# This routine makes sure $pager is set up so that '|' can use it.
4865a36d 1111pager(
e22ea7cc 1112
69893cff 1113 # If PAGER is defined in the environment, use it.
e22ea7cc
RF
1114 defined $ENV{PAGER}
1115 ? $ENV{PAGER}
69893cff
RGS
1116
1117 # If not, see if Config.pm defines it.
e22ea7cc
RF
1118 : eval { require Config }
1119 && defined $Config::Config{pager}
1120 ? $Config::Config{pager}
69893cff
RGS
1121
1122 # If not, fall back to 'more'.
e22ea7cc
RF
1123 : 'more'
1124 )
1125 unless defined $pager;
69893cff
RGS
1126
1127=pod
1128
1129We set up the command to be used to access the man pages, the command
be9a9b1d
AT
1130recall character (C<!> unless otherwise defined) and the shell escape
1131character (C<!> unless otherwise defined). Yes, these do conflict, and
69893cff
RGS
1132neither works in the debugger at the moment.
1133
1134=cut
1135
055fd3a9 1136setman();
69893cff
RGS
1137
1138# Set up defaults for command recall and shell escape (note:
1139# these currently don't work in linemode debugging).
2218c045
SF
1140recallCommand("!") unless defined $prc;
1141shellBang("!") unless defined $psh;
69893cff
RGS
1142
1143=pod
1144
1145We then set up the gigantic string containing the debugger help.
1146We also set the limit on the number of arguments we'll display during a
1147trace.
1148
1149=cut
1150
04e43a21 1151sethelp();
69893cff
RGS
1152
1153# If we didn't get a default for the length of eval/stack trace args,
1154# set it here.
1d06cb2d 1155$maxtrace = 400 unless defined $maxtrace;
69893cff
RGS
1156
1157=head2 SETTING UP THE DEBUGGER GREETING
1158
be9a9b1d 1159The debugger I<greeting> helps to inform the user how many debuggers are
69893cff
RGS
1160running, and whether the current debugger is the primary or a child.
1161
1162If we are the primary, we just hang onto our pid so we'll have it when
1163or if we start a child debugger. If we are a child, we'll set things up
1164so we'll have a unique greeting and so the parent will give us our own
1165TTY later.
1166
1167We save the current contents of the C<PERLDB_PIDS> environment variable
1168because we mess around with it. We'll also need to hang onto it because
1169we'll need it if we restart.
1170
1171Child debuggers make a label out of the current PID structure recorded in
1172PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1173yet so the parent will give them one later via C<resetterm()>.
1174
1175=cut
1176
e22ea7cc 1177# Save the current contents of the environment; we're about to
69893cff 1178# much with it. We'll need this if we have to restart.
6b24a4b7 1179use vars qw($ini_pids);
f1583d8f 1180$ini_pids = $ENV{PERLDB_PIDS};
69893cff 1181
6b24a4b7
SF
1182use vars qw ($pids $term_pid);
1183
e22ea7cc
RF
1184if ( defined $ENV{PERLDB_PIDS} ) {
1185
69893cff 1186 # We're a child. Make us a label out of the current PID structure
e22ea7cc 1187 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
69893cff 1188 # a term yet so the parent will give us one later via resetterm().
55f4245e
JM
1189
1190 my $env_pids = $ENV{PERLDB_PIDS};
1191 $pids = "[$env_pids]";
1192
1193 # Unless we are on OpenVMS, all programs under the DCL shell run under
1194 # the same PID.
1195
1196 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1197 $term_pid = $$;
1198 }
1199 else {
1200 $ENV{PERLDB_PIDS} .= "->$$";
1201 $term_pid = -1;
1202 }
1203
69893cff
RGS
1204} ## end if (defined $ENV{PERLDB_PIDS...
1205else {
e22ea7cc
RF
1206
1207 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
69893cff
RGS
1208 # child debugger, and mark us as the parent, so we'll know to set up
1209 # more TTY's is we have to.
1210 $ENV{PERLDB_PIDS} = "$$";
619a0444 1211 $pids = "[pid=$$]";
e22ea7cc 1212 $term_pid = $$;
f1583d8f 1213}
69893cff 1214
6b24a4b7 1215use vars qw($pidprompt);
f1583d8f 1216$pidprompt = '';
69893cff
RGS
1217
1218# Sets up $emacs as a synonym for $slave_editor.
7793e5c2 1219our ($slave_editor);
69893cff
RGS
1220*emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1221
1222=head2 READING THE RC FILE
1223
b570d64b 1224The debugger will read a file of initialization options if supplied. If
69893cff
RGS
1225running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1226
b570d64b 1227=cut
69893cff
RGS
1228
1229# As noted, this test really doesn't check accurately that the debugger
1230# is running at a terminal or not.
d338d6fe 1231
6b24a4b7 1232use vars qw($rcfile);
fb4d8a6c
SF
1233{
1234 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1235 # this is the wrong metric!
1236 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
d338d6fe
PP
1237}
1238
69893cff
RGS
1239=pod
1240
1241The debugger does a safety test of the file to be read. It must be owned
1242either by the current user or root, and must only be writable by the owner.
1243
1244=cut
1245
1246# This wraps a safety test around "do" to read and evaluate the init file.
1247#
055fd3a9
GS
1248# This isn't really safe, because there's a race
1249# between checking and opening. The solution is to
1250# open and fstat the handle, but then you have to read and
1251# eval the contents. But then the silly thing gets
69893cff
RGS
1252# your lexical scope, which is unfortunate at best.
1253sub safe_do {
055fd3a9
GS
1254 my $file = shift;
1255
1256 # Just exactly what part of the word "CORE::" don't you understand?
69893cff
RGS
1257 local $SIG{__WARN__};
1258 local $SIG{__DIE__};
055fd3a9 1259
e22ea7cc 1260 unless ( is_safe_file($file) ) {
69893cff 1261 CORE::warn <<EO_GRIPE;
055fd3a9 1262perldb: Must not source insecure rcfile $file.
b570d64b 1263 You or the superuser must be the owner, and it must not
69893cff 1264 be writable by anyone but its owner.
055fd3a9 1265EO_GRIPE
69893cff
RGS
1266 return;
1267 } ## end unless (is_safe_file($file...
055fd3a9
GS
1268
1269 do $file;
1270 CORE::warn("perldb: couldn't parse $file: $@") if $@;
69893cff 1271} ## end sub safe_do
055fd3a9 1272
69893cff
RGS
1273# This is the safety test itself.
1274#
055fd3a9
GS
1275# Verifies that owner is either real user or superuser and that no
1276# one but owner may write to it. This function is of limited use
1277# when called on a path instead of upon a handle, because there are
1278# no guarantees that filename (by dirent) whose file (by ino) is
e22ea7cc 1279# eventually accessed is the same as the one tested.
055fd3a9
GS
1280# Assumes that the file's existence is not in doubt.
1281sub is_safe_file {
1282 my $path = shift;
69893cff 1283 stat($path) || return; # mysteriously vaporized
e22ea7cc 1284 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
055fd3a9
GS
1285
1286 return 0 if $uid != 0 && $uid != $<;
1287 return 0 if $mode & 022;
1288 return 1;
69893cff 1289} ## end sub is_safe_file
055fd3a9 1290
69893cff 1291# If the rcfile (whichever one we decided was the right one to read)
e22ea7cc
RF
1292# exists, we safely do it.
1293if ( -f $rcfile ) {
055fd3a9 1294 safe_do("./$rcfile");
69893cff 1295}
e22ea7cc 1296
69893cff 1297# If there isn't one here, try the user's home directory.
e22ea7cc 1298elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
055fd3a9
GS
1299 safe_do("$ENV{HOME}/$rcfile");
1300}
e22ea7cc 1301
69893cff 1302# Else try the login directory.
e22ea7cc 1303elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
055fd3a9 1304 safe_do("$ENV{LOGDIR}/$rcfile");
d338d6fe
PP
1305}
1306
69893cff 1307# If the PERLDB_OPTS variable has options in it, parse those out next.
e22ea7cc
RF
1308if ( defined $ENV{PERLDB_OPTS} ) {
1309 parse_options( $ENV{PERLDB_OPTS} );
d338d6fe
PP
1310}
1311
69893cff
RGS
1312=pod
1313
1314The last thing we do during initialization is determine which subroutine is
1315to be used to obtain a new terminal when a new debugger is started. Right now,
b0b54b5e 1316the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
11653f7f 1317(darwin).
69893cff
RGS
1318
1319=cut
1320
1321# Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1322# Works if you're running an xterm or xterm-like window, or you're on
6fae1ad7
RF
1323# OS/2, or on Mac OS X. This may need some expansion.
1324
1325if (not defined &get_fork_TTY) # only if no routine exists
69893cff 1326{
b570d64b 1327 if ( defined $remoteport ) {
11653f7f
JJ
1328 # Expect an inetd-like server
1329 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1330 }
1331 elsif (defined $ENV{TERM} # If we know what kind
6fae1ad7
RF
1332 # of terminal this is,
1333 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1334 and defined $ENV{DISPLAY} # and what display it's on,
1335 )
1336 {
1337 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1338 }
babb663a
RH
1339 elsif ( $ENV{TMUX} ) {
1340 *get_fork_TTY = \&tmux_get_fork_TTY;
1341 }
6fae1ad7
RF
1342 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1343 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1344 }
1345 elsif ( $^O eq 'darwin' # If this is Mac OS X
1346 and defined $ENV{TERM_PROGRAM} # and we're running inside
1347 and $ENV{TERM_PROGRAM}
1348 eq 'Apple_Terminal' # Terminal.app
1349 )
1350 {
1351 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1352 }
69893cff 1353} ## end if (not defined &get_fork_TTY...
e22ea7cc 1354
dbb46cec
DQ
1355# untaint $^O, which may have been tainted by the last statement.
1356# see bug [perl #24674]
e22ea7cc
RF
1357$^O =~ m/^(.*)\z/;
1358$^O = $1;
f1583d8f 1359
d12a4851 1360# Here begin the unreadable code. It needs fixing.
055fd3a9 1361
69893cff
RGS
1362=head2 RESTART PROCESSING
1363
1364This section handles the restart command. When the C<R> command is invoked, it
1365tries to capture all of the state it can into environment variables, and
1366then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1367if C<PERLDB_RESTART> is there; if so, we reload all the information that
1368the R command stuffed into the environment variables.
1369
b570d64b 1370 PERLDB_RESTART - flag only, contains no restart data itself.
69893cff
RGS
1371 PERLDB_HIST - command history, if it's available
1372 PERLDB_ON_LOAD - breakpoints set by the rc file
555bd962
BG
1373 PERLDB_POSTPONE - subs that have been loaded/not executed,
1374 and have actions
69893cff
RGS
1375 PERLDB_VISITED - files that had breakpoints
1376 PERLDB_FILE_... - breakpoints for a file
1377 PERLDB_OPT - active options
1378 PERLDB_INC - the original @INC
1379 PERLDB_PRETYPE - preprompt debugger actions
1380 PERLDB_PRE - preprompt Perl code
1381 PERLDB_POST - post-prompt Perl code
1382 PERLDB_TYPEAHEAD - typeahead captured by readline()
1383
1384We chug through all these variables and plug the values saved in them
1385back into the appropriate spots in the debugger.
1386
1387=cut
1388
0664c09a 1389use vars qw(%postponed_file @typeahead);
14f38b27 1390
0664c09a 1391our (@hist, @truehist);
6b24a4b7 1392
fb0fb5f4
SF
1393sub _restore_shared_globals_after_restart
1394{
1395 @hist = get_list('PERLDB_HIST');
1396 %break_on_load = get_list("PERLDB_ON_LOAD");
1397 %postponed = get_list("PERLDB_POSTPONE");
1398
1399 share(@hist);
1400 share(@truehist);
1401 share(%break_on_load);
1402 share(%postponed);
1403}
1404
e18a02a6 1405sub _restore_breakpoints_and_actions {
e22ea7cc 1406
e22ea7cc 1407 my @had_breakpoints = get_list("PERLDB_VISITED");
e18a02a6 1408
bdba49ad
SF
1409 for my $file_idx ( 0 .. $#had_breakpoints ) {
1410 my $filename = $had_breakpoints[$file_idx];
1411 my %pf = get_list("PERLDB_FILE_$file_idx");
1412 $postponed_file{ $filename } = \%pf if %pf;
1413 my @lines = sort {$a <=> $b} keys(%pf);
1414 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1415 for my $line_idx (0 .. $#lines) {
1416 _set_breakpoint_enabled_status(
1417 $filename,
1418 $lines[$line_idx],
1419 ($enabled_statuses[$line_idx] ? 1 : ''),
1420 );
1421 }
e22ea7cc 1422 }
69893cff 1423
e18a02a6
SF
1424 return;
1425}
1426
ca50076b
SF
1427sub _restore_options_after_restart
1428{
1429 my %options_map = get_list("PERLDB_OPT");
1430
1431 while ( my ( $opt, $val ) = each %options_map ) {
1432 $val =~ s/[\\\']/\\$1/g;
1433 parse_options("$opt'$val'");
1434 }
1435
1436 return;
1437}
1438
18580168
SF
1439sub _restore_globals_after_restart
1440{
1441 # restore original @INC
1442 @INC = get_list("PERLDB_INC");
1443 @ini_INC = @INC;
1444
1445 # return pre/postprompt actions and typeahead buffer
1446 $pretype = [ get_list("PERLDB_PRETYPE") ];
1447 $pre = [ get_list("PERLDB_PRE") ];
1448 $post = [ get_list("PERLDB_POST") ];
1449 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1450
1451 return;
1452}
1453
fb0fb5f4 1454
e18a02a6
SF
1455if ( exists $ENV{PERLDB_RESTART} ) {
1456
1457 # We're restarting, so we don't need the flag that says to restart anymore.
1458 delete $ENV{PERLDB_RESTART};
1459
1460 # $restart = 1;
fb0fb5f4 1461 _restore_shared_globals_after_restart();
e18a02a6
SF
1462
1463 _restore_breakpoints_and_actions();
1464
69893cff 1465 # restore options
ca50076b 1466 _restore_options_after_restart();
69893cff 1467
18580168 1468 _restore_globals_after_restart();
69893cff
RGS
1469} ## end if (exists $ENV{PERLDB_RESTART...
1470
1471=head2 SETTING UP THE TERMINAL
1472
1473Now, we'll decide how the debugger is going to interact with the user.
1474If there's no TTY, we set the debugger to run non-stop; there's not going
1475to be anyone there to enter commands.
1476
1477=cut
54d04a52 1478
ebd0282e 1479use vars qw($notty $console $tty $LINEINFO);
6b24a4b7
SF
1480use vars qw($lineinfo $doccmd);
1481
ebd0282e
SF
1482our ($runnonstop);
1483
e0047406
KF
1484# Local autoflush to avoid rt#116769,
1485# as calling IO::File methods causes an unresolvable loop
1486# that results in debugger failure.
1487sub _autoflush {
1488 my $o = select($_[0]);
1489 $|++;
1490 select($o);
1491}
1492
d338d6fe 1493if ($notty) {
69893cff 1494 $runnonstop = 1;
2dbd01ad 1495 share($runnonstop);
69893cff 1496}
d12a4851 1497
69893cff
RGS
1498=pod
1499
1500If there is a TTY, we have to determine who it belongs to before we can
1501proceed. If this is a slave editor or graphical debugger (denoted by
1502the first command-line switch being '-emacs'), we shift this off and
1503set C<$rl> to 0 (XXX ostensibly to do straight reads).
1504
1505=cut
1506
1507else {
e22ea7cc 1508
69893cff
RGS
1509 # Is Perl being run from a slave editor or graphical debugger?
1510 # If so, don't use readline, and set $slave_editor = 1.
2b0b9dd1
SF
1511 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1512 $rl = 0;
1513 shift(@main::ARGV);
1514 }
e22ea7cc
RF
1515
1516 #require Term::ReadLine;
d12a4851 1517
69893cff
RGS
1518=pod
1519
1520We then determine what the console should be on various systems:
1521
1522=over 4
1523
1524=item * Cygwin - We use C<stdin> instead of a separate device.
1525
1526=cut
1527
e22ea7cc
RF
1528 if ( $^O eq 'cygwin' ) {
1529
69893cff
RGS
1530 # /dev/tty is binary. use stdin for textmode
1531 undef $console;
1532 }
1533
f703fc96 1534=item * Unix - use F</dev/tty>.
69893cff
RGS
1535
1536=cut
1537
e22ea7cc 1538 elsif ( -e "/dev/tty" ) {
69893cff
RGS
1539 $console = "/dev/tty";
1540 }
1541
1542=item * Windows or MSDOS - use C<con>.
1543
1544=cut
1545
e22ea7cc 1546 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
69893cff
RGS
1547 $console = "con";
1548 }
1549
69893cff
RGS
1550=item * VMS - use C<sys$command>.
1551
1552=cut
1553
1554 else {
e22ea7cc 1555
69893cff
RGS
1556 # everything else is ...
1557 $console = "sys\$command";
d12a4851 1558 }
69893cff
RGS
1559
1560=pod
1561
1562=back
1563
1564Several other systems don't use a specific console. We C<undef $console>
1565for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
739a0b84 1566with a slave editor).
69893cff
RGS
1567
1568=cut
d12a4851 1569
e22ea7cc
RF
1570 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1571
69893cff 1572 # /dev/tty is binary. use stdin for textmode
e22ea7cc
RF
1573 $console = undef;
1574 }
1575
1576 if ( $^O eq 'NetWare' ) {
d12a4851 1577
69893cff
RGS
1578 # /dev/tty is binary. use stdin for textmode
1579 $console = undef;
1580 }
d12a4851 1581
69893cff
RGS
1582 # In OS/2, we need to use STDIN to get textmode too, even though
1583 # it pretty much looks like Unix otherwise.
e22ea7cc
RF
1584 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1585 { # In OS/2
1586 $console = undef;
1587 }
1588
69893cff
RGS
1589=pod
1590
1591If there is a TTY hanging around from a parent, we use that as the console.
1592
1593=cut
1594
e22ea7cc 1595 $console = $tty if defined $tty;
d12a4851 1596
b570d64b 1597=head2 SOCKET HANDLING
69893cff
RGS
1598
1599The debugger is capable of opening a socket and carrying out a debugging
1600session over the socket.
1601
1602If C<RemotePort> was defined in the options, the debugger assumes that it
1603should try to start a debugging session on that port. It builds the socket
1604and then tries to connect the input and output filehandles to it.
1605
1606=cut
1607
1608 # Handle socket stuff.
e22ea7cc
RF
1609
1610 if ( defined $remoteport ) {
1611
69893cff
RGS
1612 # If RemotePort was defined in the options, connect input and output
1613 # to the socket.
11653f7f 1614 $IN = $OUT = connect_remoteport();
69893cff
RGS
1615 } ## end if (defined $remoteport)
1616
1617=pod
1618
1619If no C<RemotePort> was defined, and we want to create a TTY on startup,
1620this is probably a situation where multiple debuggers are running (for example,
1621a backticked command that starts up another debugger). We create a new IN and
1622OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1623and if we can.
1624
1625=cut
1626
1627 # Non-socket.
1628 else {
e22ea7cc 1629
69893cff
RGS
1630 # Two debuggers running (probably a system or a backtick that invokes
1631 # the debugger itself under the running one). create a new IN and OUT
e22ea7cc 1632 # filehandle, and do the necessary mojo to create a new tty if we
69893cff 1633 # know how, and we can.
e22ea7cc
RF
1634 create_IN_OUT(4) if $CreateTTY & 4;
1635 if ($console) {
1636
69893cff 1637 # If we have a console, check to see if there are separate ins and
cd1191f1 1638 # outs to open. (They are assumed identical if not.)
69893cff 1639
e22ea7cc
RF
1640 my ( $i, $o ) = split /,/, $console;
1641 $o = $i unless defined $o;
69893cff 1642
69893cff 1643 # read/write on in, or just read, or read on STDIN.
e22ea7cc
RF
1644 open( IN, "+<$i" )
1645 || open( IN, "<$i" )
1646 || open( IN, "<&STDIN" );
1647
69893cff
RGS
1648 # read/write/create/clobber out, or write/create/clobber out,
1649 # or merge with STDERR, or merge with STDOUT.
e22ea7cc
RF
1650 open( OUT, "+>$o" )
1651 || open( OUT, ">$o" )
1652 || open( OUT, ">&STDERR" )
1653 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1654
1655 } ## end if ($console)
1656 elsif ( not defined $console ) {
1657
1658 # No console. Open STDIN.
1659 open( IN, "<&STDIN" );
1660
1661 # merge with STDERR, or with STDOUT.
1662 open( OUT, ">&STDERR" )
1663 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1664 $console = 'STDIN/OUT';
69893cff
RGS
1665 } ## end elsif (not defined $console)
1666
1667 # Keep copies of the filehandles so that when the pager runs, it
1668 # can close standard input without clobbering ours.
2b0b9dd1
SF
1669 if ($console or (not defined($console))) {
1670 $IN = \*IN;
1671 $OUT = \*OUT;
1672 }
e22ea7cc
RF
1673 } ## end elsif (from if(defined $remoteport))
1674
1675 # Unbuffer DB::OUT. We need to see responses right away.
e0047406 1676 _autoflush($OUT);
e22ea7cc
RF
1677
1678 # Line info goes to debugger output unless pointed elsewhere.
1679 # Pointing elsewhere makes it possible for slave editors to
1680 # keep track of file and position. We have both a filehandle
1681 # and a I/O description to keep track of.
1682 $LINEINFO = $OUT unless defined $LINEINFO;
1683 $lineinfo = $console unless defined $lineinfo;
2dbd01ad
SF
1684 # share($LINEINFO); # <- unable to share globs
1685 share($lineinfo); #
e22ea7cc 1686
69893cff
RGS
1687=pod
1688
1689To finish initialization, we show the debugger greeting,
1690and then call the C<afterinit()> subroutine if there is one.
1691
1692=cut
d12a4851 1693
e22ea7cc
RF
1694 # Show the debugger greeting.
1695 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1696 unless ($runnonstop) {
1697 local $\ = '';
1698 local $, = '';
1699 if ( $term_pid eq '-1' ) {
1700 print $OUT "\nDaughter DB session started...\n";
1701 }
1702 else {
1703 print $OUT "\nLoading DB routines from $header\n";
1704 print $OUT (
1705 "Editor support ",
1706 $slave_editor ? "enabled" : "available", ".\n"
1707 );
1708 print $OUT
1f874cb6 1709"\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
69893cff
RGS
1710 } ## end else [ if ($term_pid eq '-1')
1711 } ## end unless ($runnonstop)
1712} ## end else [ if ($notty)
1713
1714# XXX This looks like a bug to me.
1715# Why copy to @ARGS and then futz with @args?
d338d6fe 1716@ARGS = @ARGV;
6b24a4b7 1717# for (@args) {
69893cff
RGS
1718 # Make sure backslashes before single quotes are stripped out, and
1719 # keep args unless they are numeric (XXX why?)
e22ea7cc
RF
1720 # s/\'/\\\'/g; # removed while not justified understandably
1721 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
6b24a4b7 1722# }
d338d6fe 1723
e22ea7cc 1724# If there was an afterinit() sub defined, call it. It will get
69893cff 1725# executed in our scope, so it can fiddle with debugger globals.
e22ea7cc 1726if ( defined &afterinit ) { # May be defined in $rcfile
2b0b9dd1 1727 afterinit();
d338d6fe 1728}
e22ea7cc 1729
69893cff 1730# Inform us about "Stack dump during die enabled ..." in dieLevel().
6b24a4b7
SF
1731use vars qw($I_m_init);
1732
43aed9ee
IZ
1733$I_m_init = 1;
1734
d338d6fe
PP
1735############################################################ Subroutines
1736
69893cff
RGS
1737=head1 SUBROUTINES
1738
1739=head2 DB
1740
1741This gigantic subroutine is the heart of the debugger. Called before every
1742statement, its job is to determine if a breakpoint has been reached, and
1743stop if so; read commands from the user, parse them, and execute
b468dcb6 1744them, and then send execution off to the next statement.
69893cff
RGS
1745
1746Note that the order in which the commands are processed is very important;
1747some commands earlier in the loop will actually alter the C<$cmd> variable
be9a9b1d 1748to create other commands to be executed later. This is all highly I<optimized>
69893cff
RGS
1749but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1750see what's happening in any given command.
1751
1752=cut
1753
136ae23d
SF
1754# $cmd cannot be an our() variable unfortunately (possible perl bug?).
1755
6b24a4b7
SF
1756use vars qw(
1757 $action
6b24a4b7 1758 $cmd
6b24a4b7
SF
1759 $file
1760 $filename_ini
1761 $finished
1762 %had_breakpoints
6b24a4b7
SF
1763 $level
1764 $max
6b24a4b7 1765 $package
6b24a4b7
SF
1766 $try
1767);
1768
1ce985d2 1769our (
bdb3f37d 1770 %alias,
1ce985d2 1771 $doret,
0664c09a 1772 $end,
4d0e1f38 1773 $fall_off_end,
d1450c23 1774 $incr,
73c5e526 1775 $laststep,
14f38b27 1776 $rc,
ddf4cf26 1777 $sh,
1ce985d2
SF
1778 $stack_depth,
1779 @stack,
1780 @to_watch,
1781 @old_watch,
1782);
8ad70697 1783
6791e41b
SF
1784sub _DB__determine_if_we_should_break
1785{
1786 # if we have something here, see if we should break.
1787 # $stop is lexical and local to this block - $action on the other hand
1788 # is global.
1789 my $stop;
1790
1791 if ( $dbline{$line}
1792 && _is_breakpoint_enabled($filename, $line)
1793 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1794 {
1795
1796 # Stop if the stop criterion says to just stop.
1797 if ( $stop eq '1' ) {
1798 $signal |= 1;
1799 }
1800
1801 # It's a conditional stop; eval it in the user's context and
1802 # see if we should stop. If so, remove the one-time sigil.
1803 elsif ($stop) {
1804 $evalarg = "\$DB::signal |= 1 if do {$stop}";
e0cd3692
SF
1805 # The &-call is here to ascertain the mutability of @_.
1806 &DB::eval;
6791e41b
SF
1807 # If the breakpoint is temporary, then delete its enabled status.
1808 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1809 _cancel_breakpoint_temp_enabled_status($filename, $line);
1810 }
1811 }
1812 } ## end if ($dbline{$line} && ...
1813}
1814
8481f647
SF
1815sub _DB__is_finished {
1816 if ($finished and $level <= 1) {
1817 end_report();
1818 return 1;
1819 }
1820 else {
1821 return;
1822 }
1823}
1824
32bbadc6
SF
1825sub _DB__read_next_cmd
1826{
1827 my ($tid) = @_;
1828
1829 # We have a terminal, or can get one ...
1830 if (!$term) {
1831 setterm();
1832 }
1833
7e3426ea 1834 # ... and it belongs to this PID or we get one for this PID ...
32bbadc6
SF
1835 if ($term_pid != $$) {
1836 resetterm(1);
1837 }
1838
1839 # ... and we got a line of command input ...
1840 $cmd = DB::readline(
1841 "$pidprompt $tid DB"
1842 . ( '<' x $level )
1843 . ( $#hist + 1 )
1844 . ( '>' x $level ) . " "
1845 );
1846
1847 return defined($cmd);
1848}
1849
7013f40c 1850sub _DB__trim_command_and_return_first_component {
af84fb69
SF
1851 my ($obj) = @_;
1852
7013f40c
SF
1853 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1854 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1855
3249b113 1856 my ($verb, $args) = $cmd =~ m{\A(\S*)\s*(.*)}s;
af84fb69 1857
3249b113
SF
1858 $obj->cmd_verb($verb);
1859 $obj->cmd_args($args);
af84fb69
SF
1860
1861 return;
7013f40c
SF
1862}
1863
2a802473 1864sub _DB__handle_f_command {
a30f63cd 1865 my ($obj) = @_;
2a802473 1866
a30f63cd 1867 if ($file = $obj->cmd_args) {
2a802473
SF
1868 # help for no arguments (old-style was return from sub).
1869 if ( !$file ) {
1870 print $OUT
1871 "The old f command is now the r command.\n"; # hint
1872 print $OUT "The new f command switches filenames.\n";
1873 next CMD;
1874 } ## end if (!$file)
1875
1876 # if not in magic file list, try a close match.
1877 if ( !defined $main::{ '_<' . $file } ) {
1878 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1879 {
1880 $try = substr( $try, 2 );
1881 print $OUT "Choosing $try matching '$file':\n";
1882 $file = $try;
1883 }
1884 } ## end if (($try) = grep(m#^_<.*$file#...
1885 } ## end if (!defined $main::{ ...
1886
1887 # If not successfully switched now, we failed.
1888 if ( !defined $main::{ '_<' . $file } ) {
1889 print $OUT "No file matching '$file' is loaded.\n";
1890 next CMD;
1891 }
1892
1893 # We switched, so switch the debugger internals around.
1894 elsif ( $file ne $filename ) {
1895 *dbline = $main::{ '_<' . $file };
1896 $max = $#dbline;
1897 $filename = $file;
1898 $start = 1;
1899 $cmd = "l";
1900 } ## end elsif ($file ne $filename)
1901
1902 # We didn't switch; say we didn't.
1903 else {
1904 print $OUT "Already in $file.\n";
1905 next CMD;
1906 }
1907 }
1908
1909 return;
1910}
1911
6115a173
SF
1912sub _DB__handle_dot_command {
1913 my ($obj) = @_;
1914
1915 # . command.
601c6a23 1916 if ($obj->_is_full('.')) {
6115a173
SF
1917 $incr = -1; # stay at current line
1918
1919 # Reset everything to the old location.
1920 $start = $line;
1921 $filename = $filename_ini;
1922 *dbline = $main::{ '_<' . $filename };
1923 $max = $#dbline;
1924
1925 # Now where are we?
1926 print_lineinfo($obj->position());
1927 next CMD;
1928 }
1929
1930 return;
1931}
1932
5c2b78e7
SF
1933sub _DB__handle_y_command {
1934 my ($obj) = @_;
1935
1936 if (my ($match_level, $match_vars)
9875a6d2 1937 = $obj->cmd_args =~ /\A(?:(\d*)\s*(.*))?\z/) {
5c2b78e7
SF
1938
1939 # See if we've got the necessary support.
84e7f475
SF
1940 if (!eval { require PadWalker; PadWalker->VERSION(0.08) }) {
1941 my $Err = $@;
b5679dc0 1942 _db_warn(
84e7f475
SF
1943 $Err =~ /locate/
1944 ? "PadWalker module not found - please install\n"
1945 : $Err
1946 );
1947 next CMD;
1948 }
5c2b78e7
SF
1949
1950 # Load up dumpvar if we don't have it. If we can, that is.
1951 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1952 defined &main::dumpvar
1953 or print $OUT "dumpvar.pl not available.\n"
1954 and next CMD;
1955
1956 # Got all the modules we need. Find them and print them.
1957 my @vars = split( ' ', $match_vars || '' );
1958
1959 # Find the pad.
496f5ba5 1960 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 2 ) };
5c2b78e7
SF
1961
1962 # Oops. Can't find it.
84e7f475
SF
1963 if (my $Err = $@) {
1964 $Err =~ s/ at .*//;
b5679dc0 1965 _db_warn($Err);
84e7f475
SF
1966 next CMD;
1967 }
5c2b78e7
SF
1968
1969 # Show the desired vars with dumplex().
1970 my $savout = select($OUT);
1971
1972 # Have dumplex dump the lexicals.
84e7f475
SF
1973 foreach my $key (sort keys %$h) {
1974 dumpvar::dumplex( $key, $h->{$key},
1975 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
1976 @vars );
1977 }
5c2b78e7
SF
1978 select($savout);
1979 next CMD;
1980 }
1981}
1982
35cd713a
SF
1983sub _DB__handle_c_command {
1984 my ($obj) = @_;
1985
a523ec7c 1986 my $i = $obj->cmd_args;
35cd713a 1987
a523ec7c 1988 if ($i =~ m#\A[\w:]*\z#) {
35cd713a
SF
1989
1990 # Hey, show's over. The debugged program finished
1991 # executing already.
1992 next CMD if _DB__is_finished();
1993
1994 # Capture the place to put a one-time break.
a523ec7c 1995 $subname = $i;
35cd713a
SF
1996
1997 # Probably not needed, since we finish an interactive
1998 # sub-session anyway...
1999 # local $filename = $filename;
2000 # local *dbline = *dbline; # XXX Would this work?!
2001 #
2002 # The above question wonders if localizing the alias
2003 # to the magic array works or not. Since it's commented
2004 # out, we'll just leave that to speculation for now.
2005
2006 # If the "subname" isn't all digits, we'll assume it
2007 # is a subroutine name, and try to find it.
2008 if ( $subname =~ /\D/ ) { # subroutine name
2009 # Qualify it to the current package unless it's
2010 # already qualified.
2011 $subname = $package . "::" . $subname
2012 unless $subname =~ /::/;
2013
2014 # find_sub will return "file:line_number" corresponding
2015 # to where the subroutine is defined; we call find_sub,
2016 # break up the return value, and assign it in one
2017 # operation.
a523ec7c 2018 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
35cd713a
SF
2019
2020 # Force the line number to be numeric.
a523ec7c 2021 $i = $i + 0;
35cd713a
SF
2022
2023 # If we got a line number, we found the sub.
a523ec7c 2024 if ($i) {
35cd713a
SF
2025
2026 # Switch all the debugger's internals around so
2027 # we're actually working with that file.
2028 $filename = $file;
2029 *dbline = $main::{ '_<' . $filename };
2030
2031 # Mark that there's a breakpoint in this file.
2032 $had_breakpoints{$filename} |= 1;
2033
2034 # Scan forward to the first executable line
2035 # after the 'sub whatever' line.
2036 $max = $#dbline;
a523ec7c 2037 my $_line_num = $i;
9c6fceaf
SF
2038 while ($dbline[$_line_num] == 0 && $_line_num< $max)
2039 {
2040 $_line_num++;
2041 }
a523ec7c 2042 $i = $_line_num;
35cd713a
SF
2043 } ## end if ($i)
2044
2045 # We didn't find a sub by that name.
2046 else {
2047 print $OUT "Subroutine $subname not found.\n";
2048 next CMD;
2049 }
2050 } ## end if ($subname =~ /\D/)
2051
2052 # At this point, either the subname was all digits (an
2053 # absolute line-break request) or we've scanned through
2054 # the code following the definition of the sub, looking
2055 # for an executable, which we may or may not have found.
2056 #
2057 # If $i (which we set $subname from) is non-zero, we
2058 # got a request to break at some line somewhere. On
2059 # one hand, if there wasn't any real subroutine name
2060 # involved, this will be a request to break in the current
2061 # file at the specified line, so we have to check to make
2062 # sure that the line specified really is breakable.
2063 #
2064 # On the other hand, if there was a subname supplied, the
2065 # preceding block has moved us to the proper file and
2066 # location within that file, and then scanned forward
2067 # looking for the next executable line. We have to make
2068 # sure that one was found.
2069 #
2070 # On the gripping hand, we can't do anything unless the
2071 # current value of $i points to a valid breakable line.
2072 # Check that.
a523ec7c 2073 if ($i) {
35cd713a
SF
2074
2075 # Breakable?
a523ec7c
SF
2076 if ( $dbline[$i] == 0 ) {
2077 print $OUT "Line $i not breakable.\n";
35cd713a
SF
2078 next CMD;
2079 }
2080
2081 # Yes. Set up the one-time-break sigil.
a523ec7c
SF
2082 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2083 _enable_breakpoint_temp_enabled_status($filename, $i);
35cd713a
SF
2084 } ## end if ($i)
2085
2086 # Turn off stack tracing from here up.
a523ec7c
SF
2087 for my $j (0 .. $stack_depth) {
2088 $stack[ $j ] &= ~1;
35cd713a
SF
2089 }
2090 last CMD;
2091 }
2092
2093 return;
2094}
2095
a4d311a3
SF
2096sub _DB__handle_forward_slash_command {
2097 my ($obj) = @_;
2098
2099 # The pattern as a string.
2100 use vars qw($inpat);
2101
2102 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2103
2104 # Remove the final slash.
2105 $inpat =~ s:([^\\])/$:$1:;
2106
2107 # If the pattern isn't null ...
2108 if ( $inpat ne "" ) {
2109
7e3426ea 2110 # Turn off warn and die processing for a bit.
a4d311a3
SF
2111 local $SIG{__DIE__};
2112 local $SIG{__WARN__};
2113
2114 # Create the pattern.
2115 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2116 if ( $@ ne "" ) {
2117
2118 # Oops. Bad pattern. No biscuit.
2119 # Print the eval error and go back for more
2120 # commands.
72c017e3 2121 print {$OUT} "$@";
a4d311a3
SF
2122 next CMD;
2123 }
2124 $obj->pat($inpat);
2125 } ## end if ($inpat ne "")
2126
2127 # Set up to stop on wrap-around.
2128 $end = $start;
2129
2130 # Don't move off the current line.
2131 $incr = -1;
2132
2133 my $pat = $obj->pat;
2134
2135 # Done in eval so nothing breaks if the pattern
2136 # does something weird.
2137 eval
2138 {
2139 no strict q/vars/;
2140 for (;;) {
2141 # Move ahead one line.
2142 ++$start;
2143
2144 # Wrap if we pass the last line.
72c017e3
SF
2145 if ($start > $max) {
2146 $start = 1;
2147 }
a4d311a3
SF
2148
2149 # Stop if we have gotten back to this line again,
2150 last if ($start == $end);
2151
2152 # A hit! (Note, though, that we are doing
2153 # case-insensitive matching. Maybe a qr//
2154 # expression would be better, so the user could
2155 # do case-sensitive matching if desired.
2156 if ($dbline[$start] =~ m/$pat/i) {
2157 if ($slave_editor) {
2158 # Handle proper escaping in the slave.
72c017e3 2159 print {$OUT} "\032\032$filename:$start:0\n";
a4d311a3
SF
2160 }
2161 else {
2162 # Just print the line normally.
72c017e3 2163 print {$OUT} "$start:\t",$dbline[$start],"\n";
a4d311a3
SF
2164 }
2165 # And quit since we found something.
2166 last;
2167 }
2168 }
2169 };
2170
2171 if ($@) {
2172 warn $@;
2173 }
2174
2175 # If we wrapped, there never was a match.
2176 if ( $start == $end ) {
2177 print {$OUT} "/$pat/: not found\n";
2178 }
2179 next CMD;
2180 }
2181
2182 return;
2183}
2184
11f0f050
SF
2185sub _DB__handle_question_mark_command {
2186 my ($obj) = @_;
2187
2188 # ? - backward pattern search.
2189 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2190
2191 # Get the pattern, remove trailing question mark.
2192 $inpat =~ s:([^\\])\?$:$1:;
2193
2194 # If we've got one ...
2195 if ( $inpat ne "" ) {
2196
2197 # Turn off die & warn handlers.
2198 local $SIG{__DIE__};
2199 local $SIG{__WARN__};
2200 eval '$inpat =~ m' . "\a$inpat\a";
2201
2202 if ( $@ ne "" ) {
2203
2204 # Ouch. Not good. Print the error.
2205 print $OUT $@;
2206 next CMD;
2207 }
2208 $obj->pat($inpat);
2209 } ## end if ($inpat ne "")
2210
2211 # Where we are now is where to stop after wraparound.
2212 $end = $start;
2213
2214 # Don't move away from this line.
2215 $incr = -1;
2216
2217 my $pat = $obj->pat;
2218 # Search inside the eval to prevent pattern badness
2219 # from killing us.
2220 eval {
2221 no strict q/vars/;
2222 for (;;) {
2223 # Back up a line.
2224 --$start;
2225
2226 # Wrap if we pass the first line.
2227
2228 $start = $max if ($start <= 0);
2229
2230 # Quit if we get back where we started,
2231 last if ($start == $end);
2232
2233 # Match?
2234 if ($dbline[$start] =~ m/$pat/i) {
2235 if ($slave_editor) {
2236 # Yep, follow slave editor requirements.
2237 print $OUT "\032\032$filename:$start:0\n";
2238 }
2239 else {
2240 # Yep, just print normally.
2241 print $OUT "$start:\t",$dbline[$start],"\n";
2242 }
2243
2244 # Found, so done.
2245 last;
2246 }
2247 }
2248 };
2249
2250 # Say we failed if the loop never found anything,
2251 if ( $start == $end ) {
2252 print {$OUT} "?$pat?: not found\n";
2253 }
2254 next CMD;
2255 }
2256
2257 return;
2258}
2259
5f166812
SF
2260sub _DB__handle_restart_and_rerun_commands {
2261 my ($obj) = @_;
2262
b9920278
SF
2263 my $cmd_cmd = $obj->cmd_verb;
2264 my $cmd_params = $obj->cmd_args;
5f166812
SF
2265 # R - restart execution.
2266 # rerun - controlled restart execution.
b9920278 2267 if ($cmd_cmd eq 'rerun' or $cmd_params eq '') {
c59f1e04
SF
2268
2269 # Change directory to the initial current working directory on
2270 # the script startup, so if the debugged program changed the
2271 # directory, then we will still be able to find the path to the
2272 # the program. (perl 5 RT #121509 ).
2273 chdir ($_initial_cwd);
2274
5f166812
SF
2275 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
2276
2277 # Close all non-system fds for a clean restart. A more
2278 # correct method would be to close all fds that were not
2279 # open when the process started, but this seems to be
2280 # hard. See "debugger 'R'estart and open database
2281 # connections" on p5p.
2282
2283 my $max_fd = 1024; # default if POSIX can't be loaded
2284 if (eval { require POSIX }) {
2285 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
2286 }
2287
2288 if (defined $max_fd) {
2289 foreach ($^F+1 .. $max_fd-1) {
2290 next unless open FD_TO_CLOSE, "<&=$_";
2291 close(FD_TO_CLOSE);
2292 }
2293 }
2294
2295 # And run Perl again. We use exec() to keep the
2296 # PID stable (and that way $ini_pids is still valid).
2297 exec(@args) or print {$OUT} "exec failed: $!\n";
2298
2299 last CMD;
2300 }
2301
2302 return;
2303}
2304
33f361f5
SF
2305sub _DB__handle_run_command_in_pager_command {
2306 my ($obj) = @_;
2307
2308 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
2309 if ( $pager =~ /^\|/ ) {
2310
2311 # Default pager is into a pipe. Redirect I/O.
2312 open( SAVEOUT, ">&STDOUT" )
b5679dc0 2313 || _db_warn("Can't save STDOUT");
33f361f5 2314 open( STDOUT, ">&OUT" )
b5679dc0 2315 || _db_warn("Can't redirect STDOUT");
33f361f5
SF
2316 } ## end if ($pager =~ /^\|/)
2317 else {
2318
2319 # Not into a pipe. STDOUT is safe.
b5679dc0 2320 open( SAVEOUT, ">&OUT" ) || _db_warn("Can't save DB::OUT");
33f361f5
SF
2321 }
2322
2323 # Fix up environment to record we have less if so.
2324 fix_less();
2325
2326 unless ( $obj->piped(scalar ( open( OUT, $pager ) ) ) ) {
2327
2328 # Couldn't open pipe to pager.
b5679dc0 2329 _db_warn("Can't pipe output to '$pager'");
33f361f5
SF
2330 if ( $pager =~ /^\|/ ) {
2331
2332 # Redirect I/O back again.
2333 open( OUT, ">&STDOUT" ) # XXX: lost message
b5679dc0 2334 || _db_warn("Can't restore DB::OUT");
33f361f5 2335 open( STDOUT, ">&SAVEOUT" )
b5679dc0 2336 || _db_warn("Can't restore STDOUT");
33f361f5
SF
2337 close(SAVEOUT);
2338 } ## end if ($pager =~ /^\|/)
2339 else {
2340
2341 # Redirect I/O. STDOUT already safe.
2342 open( OUT, ">&STDOUT" ) # XXX: lost message
b5679dc0 2343 || _db_warn("Can't restore DB::OUT");
33f361f5
SF
2344 }
2345 next CMD;
2346 } ## end unless ($piped = open(OUT,...
2347
2348 # Set up broken-pipe handler if necessary.
2349 $SIG{PIPE} = \&DB::catch
2350 if $pager =~ /^\|/
2351 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
2352
e0047406 2353 _autoflush(\*OUT);
33f361f5
SF
2354 # Save current filehandle, and put it back.
2355 $obj->selected(scalar( select(OUT) ));
2356 # Don't put it back if pager was a pipe.
2357 if ($cmd !~ /\A\|\|/)
2358 {
2359 select($obj->selected());
2360 $obj->selected("");
2361 }
2362
2363 # Trim off the pipe symbols and run the command now.
2364 $cmd =~ s#\A\|+\s*##;
2365 redo PIPE;
2366 }
2367
2368 return;
2369}
2370
321095c5
SF
2371sub _DB__handle_m_command {
2372 my ($obj) = @_;
2373
2374 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2375 methods($1);
2376 next CMD;
2377 }
2378
2379 # m expr - set up DB::eval to do the work
2380 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2381 $onetimeDump = 'methods'; # method output gets used there
2382 }
2383
2384 return;
2385}
33f361f5 2386
8e4cceb9
SF
2387sub _DB__at_end_of_every_command {
2388 my ($obj) = @_;
2389
2390 # At the end of every command:
2391 if ($obj->piped) {
2392
2393 # Unhook the pipe mechanism now.
2394 if ( $pager =~ /^\|/ ) {
2395
2396 # No error from the child.
2397 $? = 0;
2398
2399 # we cannot warn here: the handle is missing --tchrist
2400 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
2401
2402 # most of the $? crud was coping with broken cshisms
2403 # $? is explicitly set to 0, so this never runs.
2404 if ($?) {
2405 print SAVEOUT "Pager '$pager' failed: ";
2406 if ( $? == -1 ) {
2407 print SAVEOUT "shell returned -1\n";
2408 }
2409 elsif ( $? >> 8 ) {
2410 print SAVEOUT ( $? & 127 )
2411 ? " (SIG#" . ( $? & 127 ) . ")"
2412 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
2413 }
2414 else {
2415 print SAVEOUT "status ", ( $? >> 8 ), "\n";
2416 }
2417 } ## end if ($?)
2418
2419 # Reopen filehandle for our output (if we can) and
2420 # restore STDOUT (if we can).
b5679dc0 2421 open( OUT, ">&STDOUT" ) || _db_warn("Can't restore DB::OUT");
8e4cceb9 2422 open( STDOUT, ">&SAVEOUT" )
b5679dc0 2423 || _db_warn("Can't restore STDOUT");
8e4cceb9
SF
2424
2425 # Turn off pipe exception handler if necessary.
2426 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
2427
2428 # Will stop ignoring SIGPIPE if done like nohup(1)
2429 # does SIGINT but Perl doesn't give us a choice.
2430 } ## end if ($pager =~ /^\|/)
2431 else {
2432
2433 # Non-piped "pager". Just restore STDOUT.
b5679dc0 2434 open( OUT, ">&SAVEOUT" ) || _db_warn("Can't restore DB::OUT");
8e4cceb9
SF
2435 }
2436
9b534162
HH
2437 # Let Readline know about the new filehandles.
2438 reset_IN_OUT( \*IN, \*OUT );
2439
8e4cceb9
SF
2440 # Close filehandle pager was using, restore the normal one
2441 # if necessary,
2442 close(SAVEOUT);
2443
2444 if ($obj->selected() ne "") {
2445 select($obj->selected);
2446 $obj->selected("");
2447 }
2448
2449 # No pipes now.
2450 $obj->piped("");
2451 } ## end if ($piped)
2452
2453 return;
2454}
2455
5f5eab52
SF
2456sub _DB__handle_watch_expressions
2457{
2458 my $self = shift;
2459
2460 if ( $DB::trace & 2 ) {
2461 for my $n (0 .. $#DB::to_watch) {
2462 $DB::evalarg = $DB::to_watch[$n];
2463 local $DB::onetimeDump; # Tell DB::eval() to not output results
2464
2465 # Fix context DB::eval() wants to return an array, but
2466 # we need a scalar here.
2467 my ($val) = join( "', '", DB::eval(@_) );
2468 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
2469
2470 # Did it change?
2471 if ( $val ne $DB::old_watch[$n] ) {
2472
2473 # Yep! Show the difference, and fake an interrupt.
2474 $DB::signal = 1;
2475 print {$DB::OUT} <<EOP;
2476Watchpoint $n:\t$DB::to_watch[$n] changed:
2477 old value:\t$DB::old_watch[$n]
2478 new value:\t$val
2479EOP
2480 $DB::old_watch[$n] = $val;
2481 } ## end if ($val ne $old_watch...
2482 } ## end for my $n (0 ..
2483 } ## end if ($trace & 2)
2484
2485 return;
2486}
2487
47e3b8cc
SF
2488# 't' is type.
2489# 'm' is method.
2490# 'v' is the value (i.e: method name or subroutine ref).
2491# 's' is subroutine.
2492my %cmd_lookup =
2493(
c9a9a6c0 2494 '-' => { t => 'm', v => '_handle_dash_command', },
d478d7a0 2495 '.' => { t => 's', v => \&_DB__handle_dot_command, },
8f144dfc
SF
2496 '=' => { t => 'm', v => '_handle_equal_sign_command', },
2497 'H' => { t => 'm', v => '_handle_H_command', },
c9a9a6c0
SF
2498 'S' => { t => 'm', v => '_handle_S_command', },
2499 'T' => { t => 'm', v => '_handle_T_command', },
8f144dfc 2500 'W' => { t => 'm', v => '_handle_W_command', },
c9a9a6c0 2501 'c' => { t => 's', v => \&_DB__handle_c_command, },
d478d7a0
SF
2502 'f' => { t => 's', v => \&_DB__handle_f_command, },
2503 'm' => { t => 's', v => \&_DB__handle_m_command, },
c9a9a6c0 2504 'n' => { t => 'm', v => '_handle_n_command', },
8f144dfc 2505 'p' => { t => 'm', v => '_handle_p_command', },
d478d7a0 2506 'q' => { t => 'm', v => '_handle_q_command', },
c9a9a6c0
SF
2507 'r' => { t => 'm', v => '_handle_r_command', },
2508 's' => { t => 'm', v => '_handle_s_command', },
8f144dfc
SF
2509 'save' => { t => 'm', v => '_handle_save_command', },
2510 'source' => { t => 'm', v => '_handle_source_command', },
d478d7a0 2511 't' => { t => 'm', v => '_handle_t_command', },
8f144dfc 2512 'w' => { t => 'm', v => '_handle_w_command', },
d478d7a0 2513 'x' => { t => 'm', v => '_handle_x_command', },
c9a9a6c0 2514 'y' => { t => 's', v => \&_DB__handle_y_command, },
d478d7a0
SF
2515 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, }
2516 ('X', 'V')),
8f144dfc
SF
2517 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, }
2518 qw(enable disable)),
2519 (map { $_ =>
2520 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, },
2521 } qw(R rerun)),
fbe9ebae 2522 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, }
ce1a6808 2523 qw(a A b B e E h i l L M o O v w W)),
47e3b8cc
SF
2524);
2525
2b0b9dd1
SF
2526sub DB {
2527
2528 # lock the debugger and get the thread id for the prompt
2529 lock($DBGR);
2530 my $tid;
2531 my $position;
2532 my ($prefix, $after, $infix);
2533 my $pat;
22fc883d 2534 my $explicit_stop;
33f361f5
SF
2535 my $piped;
2536 my $selected;
2b0b9dd1
SF
2537
2538 if ($ENV{PERL5DB_THREADED}) {
2539 $tid = eval { "[".threads->tid."]" };
2540 }
2541
610f01b9 2542 my $cmd_verb;
3249b113 2543 my $cmd_args;
35cd713a 2544
22fc883d
SF
2545 my $obj = DB::Obj->new(
2546 {
2547 position => \$position,
2548 prefix => \$prefix,
2549 after => \$after,
2550 explicit_stop => \$explicit_stop,
2551 infix => \$infix,
3249b113 2552 cmd_args => \$cmd_args,
610f01b9 2553 cmd_verb => \$cmd_verb,
a4d311a3 2554 pat => \$pat,
33f361f5
SF
2555 piped => \$piped,
2556 selected => \$selected,
22fc883d
SF
2557 },
2558 );
2559
2560 $obj->_DB_on_init__initialize_globals(@_);
2b0b9dd1 2561
69893cff
RGS
2562 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2563 # The code being debugged may have altered them.
b0b8faca 2564 DB::save();
69893cff
RGS
2565
2566 # Since DB::DB gets called after every line, we can use caller() to
2567 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 2568 # caller is returning all the extra information when called from the
69893cff 2569 # debugger.
e22ea7cc 2570 local ( $package, $filename, $line ) = caller;
6b24a4b7 2571 $filename_ini = $filename;
69893cff
RGS
2572
2573 # set up the context for DB::eval, so it can properly execute
2574 # code on behalf of the user. We add the package in so that the
2575 # code is eval'ed in the proper package (not in the debugger!).
6b24a4b7 2576 local $usercontext = _calc_usercontext($package);
69893cff
RGS
2577
2578 # Create an alias to the active file magical array to simplify
2579 # the code here.
e22ea7cc 2580 local (*dbline) = $main::{ '_<' . $filename };
aa057b67 2581
69893cff 2582 # Last line in the program.
55783941 2583 $max = $#dbline;
69893cff 2584
e0cd3692
SF
2585 # The &-call is here to ascertain the mutability of @_.
2586 &_DB__determine_if_we_should_break;
69893cff
RGS
2587
2588 # Preserve the current stop-or-not, and see if any of the W
2589 # (watch expressions) has changed.
36477c24 2590 my $was_signal = $signal;
69893cff
RGS
2591
2592 # If we have any watch expressions ...
5f5eab52 2593 _DB__handle_watch_expressions($obj);
69893cff
RGS
2594
2595=head2 C<watchfunction()>
2596
2597C<watchfunction()> is a function that can be defined by the user; it is a
b570d64b 2598function which will be run on each entry to C<DB::DB>; it gets the
69893cff
RGS
2599current package, filename, and line as its parameters.
2600
b570d64b 2601The watchfunction can do anything it likes; it is executing in the
69893cff
RGS
2602debugger's context, so it has access to all of the debugger's internal
2603data structures and functions.
2604
2605C<watchfunction()> can control the debugger's actions. Any of the following
2606will cause the debugger to return control to the user's program after
2607C<watchfunction()> executes:
2608
b570d64b 2609=over 4
69893cff 2610
be9a9b1d
AT
2611=item *
2612
2613Returning a false value from the C<watchfunction()> itself.
2614
2615=item *
2616
2617Altering C<$single> to a false value.
2618
2619=item *
69893cff 2620
be9a9b1d 2621Altering C<$signal> to a false value.
69893cff 2622
be9a9b1d 2623=item *
69893cff 2624
be9a9b1d 2625Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
2626check for C<watchfunction()>. This can be done with
2627
2628 $trace &= ~4;
2629
2630=back
2631
2632=cut
2633
e22ea7cc 2634 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
2635 # current package, filename, and line. The function executes in
2636 # the DB:: package.
e22ea7cc
RF
2637 if ( $trace & 4 ) { # User-installed watch
2638 return
2639 if watchfunction( $package, $filename, $line )
2640 and not $single
2641 and not $was_signal
2642 and not( $trace & ~4 );
69893cff
RGS
2643 } ## end if ($trace & 4)
2644
e22ea7cc 2645 # Pick up any alteration to $signal in the watchfunction, and
69893cff 2646 # turn off the signal now.
6027b9a3 2647 $was_signal = $signal;
69893cff
RGS
2648 $signal = 0;
2649
2650=head2 GETTING READY TO EXECUTE COMMANDS
2651
2652The debugger decides to take control if single-step mode is on, the
2653C<t> command was entered, or the user generated a signal. If the program
2654has fallen off the end, we set things up so that entering further commands
2655won't cause trouble, and we say that the program is over.
2656
2657=cut
2658
8dc67a69
SF
2659 # Make sure that we always print if asked for explicitly regardless
2660 # of $trace_to_depth .
22fc883d 2661 $explicit_stop = ($single || $was_signal);
8dc67a69 2662
69893cff
RGS
2663 # Check to see if we should grab control ($single true,
2664 # trace set appropriately, or we got a signal).
8dc67a69 2665 if ( $explicit_stop || ( $trace & 1 ) ) {
22fc883d 2666 $obj->_DB__grab_control(@_);
69893cff
RGS
2667 } ## end if ($single || ($trace...
2668
2669=pod
2670
2671If there's an action to be executed for the line we stopped at, execute it.
b570d64b 2672If there are any preprompt actions, execute those as well.
e219e2fb
RF
2673
2674=cut
2675
69893cff 2676 # If there's an action, do it now.
05da04df
SF
2677 if ($action) {
2678 $evalarg = $action;
e0cd3692
SF
2679 # The &-call is here to ascertain the mutability of @_.
2680 &DB::eval;
05da04df 2681 }
e219e2fb 2682
69893cff
RGS
2683 # Are we nested another level (e.g., did we evaluate a function
2684 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
2685 if ( $single || $was_signal ) {
2686
69893cff 2687 # Yes, go down a level.
e22ea7cc 2688 local $level = $level + 1;
69893cff
RGS
2689
2690 # Do any pre-prompt actions.
e22ea7cc 2691 foreach $evalarg (@$pre) {
e0cd3692
SF
2692 # The &-call is here to ascertain the mutability of @_.
2693 &DB::eval;
e22ea7cc 2694 }
69893cff
RGS
2695
2696 # Complain about too much recursion if we passed the limit.
05da04df
SF
2697 if ($single & 4) {
2698 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2699 }
69893cff
RGS
2700
2701 # The line we're currently on. Set $incr to -1 to stay here
2702 # until we get a command that tells us to advance.
e22ea7cc
RF
2703 $start = $line;
2704 $incr = -1; # for backward motion.
69893cff
RGS
2705
2706 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 2707 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
2708
2709=head2 WHERE ARE WE?
2710
2711XXX Relocate this section?
2712
2713The debugger normally shows the line corresponding to the current line of
2714execution. Sometimes, though, we want to see the next line, or to move elsewhere
2715in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2716
be9a9b1d
AT
2717C<$incr> controls by how many lines the I<current> line should move forward
2718after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2719line shouldn't change.
2720
be9a9b1d 2721C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2722move forwards or backwards from when doing an C<L> or C<-> command.
2723
2724C<$max> tells the debugger where the last line of the current file is. It's
2725used to terminate loops most often.
2726
2727=head2 THE COMMAND LOOP
2728
2729Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2730in two parts:
2731
2732=over 4
2733
be9a9b1d
AT
2734=item *
2735
2736The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2737reads a command and then executes it.
2738
be9a9b1d
AT
2739=item *
2740
2741The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2742is wholly contained inside the C<CMD> block and only executes a command.
2743Used to handle commands running inside a pager.
2744
2745=back
2746
2747So why have two labels to restart the loop? Because sometimes, it's easier to
2748have a command I<generate> another command and then re-execute the loop to do
2749the new command. This is faster, but perhaps a bit more convoluted.
2750
2751=cut
2752
2753 # The big command dispatch loop. It keeps running until the
2754 # user yields up control again.
2755 #
2756 # If we have a terminal for input, and we get something back
2757 # from readline(), keep on processing.
6b24a4b7 2758
e22ea7cc 2759 CMD:
32bbadc6 2760 while (_DB__read_next_cmd($tid))
69893cff 2761 {
e22ea7cc 2762
8380a245 2763 share($cmd);
69893cff
RGS
2764 # ... try to execute the input as debugger commands.
2765
2766 # Don't stop running.
2767 $single = 0;
2768
2769 # No signal is active.
2770 $signal = 0;
2771
2772 # Handle continued commands (ending with \):
3d7a2a93 2773 if ($cmd =~ s/\\\z/\n/) {
eeb7da96 2774 $cmd .= DB::readline(" cont: ");
e22ea7cc 2775 redo CMD;
3d7a2a93 2776 }
69893cff
RGS
2777
2778=head4 The null command
2779
be9a9b1d 2780A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2781command out of C<$laststep> (where it was recorded previously), and copy it
2782back into C<$cmd> to be executed below. If there wasn't any previous command,
2783we'll do nothing below (no command will match). If there was, we also save it
2784in the command history and fall through to allow the command parsing to pick
2785it up.
2786
2787=cut
2788
2789 # Empty input means repeat the last command.
eeb7da96
SF
2790 if ($cmd eq '') {
2791 $cmd = $laststep;
2792 }
e22ea7cc 2793 chomp($cmd); # get rid of the annoying extra newline
eeb7da96
SF
2794 if (length($cmd) >= 2) {
2795 push( @hist, $cmd );
2796 }
e22ea7cc 2797 push( @truehist, $cmd );
2dbd01ad
SF
2798 share(@hist);
2799 share(@truehist);
e22ea7cc
RF
2800
2801 # This is a restart point for commands that didn't arrive
2802 # via direct user input. It allows us to 'redo PIPE' to
2803 # re-execute command processing without reading a new command.
69893cff 2804 PIPE: {
af84fb69 2805 _DB__trim_command_and_return_first_component($obj);
69893cff
RGS
2806
2807=head3 COMMAND ALIASES
2808
2809The debugger can create aliases for commands (these are stored in the
2810C<%alias> hash). Before a command is executed, the command loop looks it up
2811in the alias hash and substitutes the contents of the alias for the command,
2812completely replacing it.
2813
2814=cut
2815
2816 # See if there's an alias for the command, and set it up if so.
610f01b9 2817 if ( $alias{$cmd_verb} ) {
e22ea7cc 2818
69893cff
RGS
2819 # Squelch signal handling; we want to keep control here
2820 # if something goes loco during the alias eval.
2821 local $SIG{__DIE__};
2822 local $SIG{__WARN__};
2823
2824 # This is a command, so we eval it in the DEBUGGER's
2825 # scope! Otherwise, we can't see the special debugger
2826 # variables, or get to the debugger's subs. (Well, we
2827 # _could_, but why make it even more complicated?)
610f01b9 2828 eval "\$cmd =~ $alias{$cmd_verb}";
69893cff
RGS
2829 if ($@) {
2830 local $\ = '';
610f01b9 2831 print $OUT "Couldn't evaluate '$cmd_verb' alias: $@";
69893cff
RGS
2832 next CMD;
2833 }
af84fb69 2834 _DB__trim_command_and_return_first_component($obj);
610f01b9 2835 } ## end if ($alias{$cmd_verb})
69893cff
RGS
2836
2837=head3 MAIN-LINE COMMANDS
2838
2839All of these commands work up to and after the program being debugged has
b570d64b 2840terminated.
69893cff
RGS
2841
2842=head4 C<q> - quit
2843
b570d64b 2844Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
69893cff
RGS
2845try to execute further, cleaning any restart-related stuff out of the
2846environment, and executing with the last value of C<$?>.
2847
2848=cut
2849
fbe9ebae
SF
2850 # All of these commands were remapped in perl 5.8.0;
2851 # we send them off to the secondary dispatcher (see below).
2852 $obj->_handle_special_char_cmd_wrapper_commands;
af84fb69 2853 _DB__trim_command_and_return_first_component($obj);
fbe9ebae 2854
610f01b9 2855 if (my $cmd_rec = $cmd_lookup{$cmd_verb}) {
47e3b8cc
SF
2856 my $type = $cmd_rec->{t};
2857 my $val = $cmd_rec->{v};
2858 if ($type eq 'm') {
2859 $obj->$val();
2860 }
2861 elsif ($type eq 's') {
2862 $val->($obj);
2863 }
2864 }
69893cff 2865
611272bb 2866=head4 C<t> - trace [n]
69893cff
RGS
2867
2868Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
611272bb 2869If level is specified, set C<$trace_to_depth>.
69893cff 2870
69893cff
RGS
2871=head4 C<S> - list subroutines matching/not matching a pattern
2872
2873Walks through C<%sub>, checking to see whether or not to print the name.
2874
69893cff
RGS
2875=head4 C<X> - list variables in current package
2876
b570d64b 2877Since the C<V> command actually processes this, just change this to the
69893cff
RGS
2878appropriate C<V> command and fall through.
2879
69893cff
RGS
2880=head4 C<V> - list variables
2881
b570d64b 2882Uses C<dumpvar.pl> to dump out the current values for selected variables.
69893cff 2883
69893cff
RGS
2884=head4 C<x> - evaluate and print an expression
2885
2886Hands the expression off to C<DB::eval>, setting it up to print the value
2887via C<dumpvar.pl> instead of just printing it directly.
2888
69893cff
RGS
2889=head4 C<m> - print methods
2890
2891Just uses C<DB::methods> to determine what methods are available.
2892
69893cff
RGS
2893=head4 C<f> - switch files
2894
73decac7 2895Switch to a different filename.
69893cff 2896
69893cff
RGS
2897=head4 C<.> - return to last-executed line.
2898
2899We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2900and then we look up the line in the magical C<%dbline> hash.
2901
69893cff
RGS
2902=head4 C<-> - back one window
2903
2904We change C<$start> to be one window back; if we go back past the first line,
2905we set it to be the first line. We ser C<$incr> to put us back at the
2906currently-executing line, and then put a C<l $start +> (list one window from
2907C<$start>) in C<$cmd> to be executed later.
2908
8481f647 2909=head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
69893cff
RGS
2910
2911In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2912problems, most notably that the default case of several commands destroying
2913the user's work in setting watchpoints, actions, etc. We wanted, however, to
2914retain the old commands for those who were used to using them or who preferred
2915them. At this point, we check for the new commands and call C<cmd_wrapper> to
2916deal with them instead of processing them in-line.
2917
69893cff
RGS
2918=head4 C<y> - List lexicals in higher scope
2919
826b9a2e 2920Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
69893cff
RGS
2921above the current one and then displays then using C<dumpvar.pl>.
2922
69893cff
RGS
2923=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2924
2925All of the commands below this point don't work after the program being
2926debugged has ended. All of them check to see if the program has ended; this
2927allows the commands to be relocated without worrying about a 'line of
2928demarcation' above which commands can be entered anytime, and below which
2929they can't.
2930
2931=head4 C<n> - single step, but don't trace down into subs
2932
2933Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2934when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
826b9a2e 2935so a null command knows what to re-execute.
69893cff 2936
69893cff
RGS
2937=head4 C<s> - single-step, entering subs
2938
826b9a2e 2939Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2940subs. Also saves C<s> as C<$lastcmd>.
2941
69893cff
RGS
2942=head4 C<c> - run continuously, setting an optional breakpoint
2943
2944Most of the code for this command is taken up with locating the optional
2945breakpoint, which is either a subroutine name or a line number. We set
2946the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2947in this and all call levels above this one.
2948
69893cff
RGS
2949=head4 C<r> - return from a subroutine
2950
2951For C<r> to work properly, the debugger has to stop execution again
2952immediately after the return is executed. This is done by forcing
2953single-stepping to be on in the call level above the current one. If
2954we are printing return values when a C<r> is executed, set C<$doret>
2955appropriately, and force us out of the command loop.
2956
69893cff
RGS
2957=head4 C<T> - stack trace
2958
2959Just calls C<DB::print_trace>.
2960
69893cff
RGS
2961=head4 C<w> - List window around current line.
2962
2963Just calls C<DB::cmd_w>.
2964
69893cff
RGS
2965=head4 C<W> - watch-expression processing.
2966
b570d64b 2967Just calls C<DB::cmd_W>.
69893cff 2968
69893cff
RGS
2969=head4 C</> - search forward for a string in the source
2970
ef18ae63 2971We take the argument and treat it as a pattern. If it turns out to be a
69893cff 2972bad one, we return the error we got from trying to C<eval> it and exit.
ef18ae63 2973If not, we create some code to do the search and C<eval> it so it can't
69893cff
RGS
2974mess us up.
2975
2976=cut
2977
a4d311a3 2978 _DB__handle_forward_slash_command($obj);
69893cff
RGS
2979
2980=head4 C<?> - search backward for a string in the source
2981
2982Same as for C</>, except the loop runs backwards.
2983
2984=cut
2985
11f0f050 2986 _DB__handle_question_mark_command($obj);
69893cff
RGS
2987
2988=head4 C<$rc> - Recall command
2989
2990Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
7e3426ea 2991that the terminal supports history). It finds the command required, puts it
69893cff
RGS
2992into C<$cmd>, and redoes the loop to execute it.
2993
2994=cut
2995
e22ea7cc 2996 # $rc - recall command.
14f38b27 2997 $obj->_handle_rc_recall_command;
69893cff
RGS
2998
2999=head4 C<$sh$sh> - C<system()> command
3000
f0bb1409 3001Calls the C<_db_system()> to handle the command. This keeps the C<STDIN> and
69893cff
RGS
3002C<STDOUT> from getting messed up.
3003
3004=cut
3005
466f24c7 3006 $obj->_handle_sh_command;
69893cff
RGS
3007
3008=head4 C<$rc I<pattern> $rc> - Search command history
3009
3010Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 3011If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
3012
3013=cut
3014
0d2c714c 3015 $obj->_handle_rc_search_history_command;
69893cff 3016
ef18ae63 3017=head4 C<$sh> - Invoke a shell
69893cff 3018
f0bb1409 3019Uses C<_db_system()> to invoke a shell.
69893cff
RGS
3020
3021=cut
3022
69893cff
RGS
3023=head4 C<$sh I<command>> - Force execution of a command in a shell
3024
3025Like the above, but the command is passed to the shell. Again, we use
f0bb1409 3026C<_db_system()> to avoid problems with C<STDIN> and C<STDOUT>.
69893cff 3027
69893cff
RGS
3028=head4 C<H> - display commands in history
3029
3030Prints the contents of C<@hist> (if any).
3031
69893cff
RGS
3032=head4 C<man, doc, perldoc> - look up documentation
3033
3034Just calls C<runman()> to print the appropriate document.
3035
3036=cut
3037
c7b0c61d 3038 $obj->_handle_doc_command;
69893cff
RGS
3039
3040=head4 C<p> - print
3041
3042Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3043the bottom of the loop.
3044
69893cff
RGS
3045=head4 C<=> - define command alias
3046
3047Manipulates C<%alias> to add or list command aliases.
3048
69893cff
RGS
3049=head4 C<source> - read commands from a file.
3050
3051Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3052pick it up.
3053
d0ecd4f3 3054=head4 C<enable> C<disable> - enable or disable breakpoints
e09195af 3055
d0ecd4f3 3056This enables or disables breakpoints.
e09195af 3057
69893cff
RGS
3058=head4 C<save> - send current history to a file
3059
3060Takes the complete history, (not the shrunken version you see with C<H>),
3061and saves it to the given filename, so it can be replayed using C<source>.
3062
3063Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3064
7fddc82f
RF
3065=head4 C<R> - restart
3066
ef18ae63 3067Restart the debugger session.
7fddc82f
RF
3068
3069=head4 C<rerun> - rerun the current session
3070
3071Return to any given position in the B<true>-history list
3072
69893cff
RGS
3073=head4 C<|, ||> - pipe output through the pager.
3074
be9a9b1d 3075For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
3076(the program's standard output). For C<||>, we only save C<OUT>. We open a
3077pipe to the pager (restoring the output filehandles if this fails). If this
b570d64b 3078is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
69893cff
RGS
3079set C<$signal>, sending us back into the debugger.
3080
3081We then trim off the pipe symbols and C<redo> the command loop at the
3082C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3083reading another.
3084
3085=cut
3086
3087 # || - run command in the pager, with output to DB::OUT.
33f361f5 3088 _DB__handle_run_command_in_pager_command($obj);
69893cff
RGS
3089
3090=head3 END OF COMMAND PARSING
3091
ff41e38d
SF
3092Anything left in C<$cmd> at this point is a Perl expression that we want to
3093evaluate. We'll always evaluate in the user's context, and fully qualify
69893cff
RGS
3094any variables we might want to address in the C<DB> package.
3095
3096=cut
3097
e22ea7cc 3098 } # PIPE:
69893cff 3099
e2b8b3e7
TC
3100 # trace an expression
3101 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3102
e22ea7cc 3103 # Make sure the flag that says "the debugger's running" is
69893cff 3104 # still on, to make sure we get control again.
e22ea7cc 3105 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3106
3107 # Run *our* eval that executes in the caller's context.
e0cd3692
SF
3108 # The &-call is here to ascertain the mutability of @_.
3109 &DB::eval;
69893cff
RGS
3110
3111 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3112 if ($onetimeDump) {
3113 $onetimeDump = undef;
69893cff 3114 $onetimedumpDepth = undef;
e22ea7cc
RF
3115 }
3116 elsif ( $term_pid == $$ ) {
8380a245 3117 eval { # May run under miniperl, when not available...
c7e68384
IZ
3118 STDOUT->flush();
3119 STDERR->flush();
8380a245 3120 };
e22ea7cc 3121
69893cff 3122 # XXX If this is the master pid, print a newline.
8380a245 3123 print {$OUT} "\n";
e22ea7cc
RF
3124 }
3125 } ## end while (($term || &setterm...
69893cff
RGS
3126
3127=head3 POST-COMMAND PROCESSING
3128
3129After each command, we check to see if the command output was piped anywhere.
3130If so, we go through the necessary code to unhook the pipe and go back to
3131our standard filehandles for input and output.
3132
3133=cut
3134
e22ea7cc 3135 continue { # CMD:
8e4cceb9 3136 _DB__at_end_of_every_command($obj);
e22ea7cc 3137 } # CMD:
69893cff
RGS
3138
3139=head3 COMMAND LOOP TERMINATION
3140
3141When commands have finished executing, we come here. If the user closed the
3142input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3143evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3144C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3145The interpreter will then execute the next line and then return control to us
3146again.
3147
3148=cut
3149
3150 # No more commands? Quit.
1f874cb6 3151 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
69893cff
RGS
3152
3153 # Evaluate post-prompt commands.
e22ea7cc 3154 foreach $evalarg (@$post) {
e0cd3692
SF
3155 # The &-call is here to ascertain the mutability of @_.
3156 &DB::eval;
e22ea7cc
RF
3157 }
3158 } # if ($single || $signal)
69893cff
RGS
3159
3160 # Put the user's globals back where you found them.
e22ea7cc 3161 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3162 ();
3163} ## end sub DB
3164
90fd4c80
KF
3165# Because DB::Obj is used above,
3166#
3167# my $obj = DB::Obj->new(
3168#
7e3426ea 3169# The following package declaration must come before that,
90fd4c80
KF
3170# or else runtime errors will occur with
3171#
3172# PERLDB_OPTS="autotrace nonstop"
3173#
3174# ( rt#116771 )
3175BEGIN {
3176
22fc883d
SF
3177package DB::Obj;
3178
3179sub new {
3180 my $class = shift;
3181
3182 my $self = bless {}, $class;
3183
3184 $self->_init(@_);
3185
3186 return $self;
3187}
3188
3189sub _init {
3190 my ($self, $args) = @_;
3191
3192 %{$self} = (%$self, %$args);
3193
3194 return;
3195}
3196
3197{
3198 no strict 'refs';
a4d311a3 3199 foreach my $slot_name (qw(
610f01b9 3200 after explicit_stop infix pat piped position prefix selected cmd_verb
3249b113 3201 cmd_args
a4d311a3 3202 )) {
22fc883d
SF
3203 my $slot = $slot_name;
3204 *{$slot} = sub {
3205 my $self = shift;
3206
3207 if (@_) {
3208 ${ $self->{$slot} } = shift;
3209 }
3210
3211 return ${ $self->{$slot} };
3212 };
8def6eff
SF
3213
3214 *{"append_to_$slot"} = sub {
3215 my $self = shift;
3216 my $s = shift;
3217
3218 return $self->$slot($self->$slot . $s);
3219 };
22fc883d
SF
3220 }
3221}
3222
3223sub _DB_on_init__initialize_globals
3224{
3225 my $self = shift;
3226
3227 # Check for whether we should be running continuously or not.
3228 # _After_ the perl program is compiled, $single is set to 1:
ebd0282e 3229 if ( $single and not $second_time++ ) {
22fc883d
SF
3230
3231 # Options say run non-stop. Run until we get an interrupt.
ebd0282e 3232 if ($runnonstop) { # Disable until signal
22fc883d
SF
3233 # If there's any call stack in place, turn off single
3234 # stepping into subs throughout the stack.
8ad70697
SF
3235 for my $i (0 .. $stack_depth) {
3236 $stack[ $i ] &= ~1;
22fc883d
SF
3237 }
3238
3239 # And we are now no longer in single-step mode.
ebd0282e 3240 $single = 0;
22fc883d
SF
3241
3242 # If we simply returned at this point, we wouldn't get
3243 # the trace info. Fall on through.
3244 # return;
3245 } ## end if ($runnonstop)
3246
8ad70697 3247 elsif ($ImmediateStop) {
22fc883d
SF
3248
3249 # We are supposed to stop here; XXX probably a break.
8ad70697 3250 $ImmediateStop = 0; # We've processed it; turn it off
ebd0282e 3251 $signal = 1; # Simulate an interrupt to force
22fc883d
SF
3252 # us into the command loop
3253 }
3254 } ## end if ($single and not $second_time...
3255
3256 # If we're in single-step mode, or an interrupt (real or fake)
3257 # has occurred, turn off non-stop mode.
ebd0282e 3258 $runnonstop = 0 if $single or $signal;
22fc883d
SF
3259
3260 return;
3261}
3262
ad46ac70
SF
3263sub _my_print_lineinfo
3264{
3265 my ($self, $i, $incr_pos) = @_;
3266
18b5b545 3267 if ($frame) {
ad46ac70 3268 # Print it indented if tracing is on.
8ad70697 3269 DB::print_lineinfo( ' ' x $stack_depth,
ad46ac70
SF
3270 "$i:\t$DB::dbline[$i]" . $self->after );
3271 }
3272 else {
3273 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3274 }
3275}
3276
44a07e3e 3277sub _curr_line {
18b5b545 3278 return $DB::dbline[$line];
44a07e3e
SF
3279}
3280
601c6a23
SF
3281sub _is_full {
3282 my ($self, $letter) = @_;
3283
3284 return ($DB::cmd eq $letter);
3285}
3286
22fc883d
SF
3287sub _DB__grab_control
3288{
3289 my $self = shift;
3290
3291 # Yes, grab control.
7793e5c2 3292 if ($slave_editor) {
22fc883d
SF
3293
3294 # Tell the editor to update its position.
18b5b545 3295 $self->position("\032\032${DB::filename}:$line:0\n");
22fc883d
SF
3296 DB::print_lineinfo($self->position());
3297 }
3298
3299=pod
3300
3301Special check: if we're in package C<DB::fake>, we've gone through the
3302C<END> block at least once. We set up everything so that we can continue
3303to enter commands and have a valid context to be in.
3304
3305=cut
3306
3307 elsif ( $DB::package eq 'DB::fake' ) {
3308
3309 # Fallen off the end already.
3310 if (!$DB::term) {
3311 DB::setterm();
3312 }
3313
3314 DB::print_help(<<EOP);
3315Debugged program terminated. Use B<q> to quit or B<R> to restart,
3316use B<o> I<inhibit_exit> to avoid stopping after program termination,
3317B<h q>, B<h R> or B<h o> to get additional info.
3318EOP
3319
3320 # Set the DB::eval context appropriately.
3321 $DB::package = 'main';
3322 $DB::usercontext = DB::_calc_usercontext($DB::package);
3323 } ## end elsif ($package eq 'DB::fake')
3324
3325=pod
3326
3327If the program hasn't finished executing, we scan forward to the
3328next executable line, print that out, build the prompt from the file and line
3329number information, and print that.
3330
3331=cut
3332
3333 else {
3334
3335
3336 # Still somewhere in the midst of execution. Set up the
3337 # debugger prompt.
3338 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3339 # Perl 5 ones (sorry, we don't print Klingon
3340 #module names)
3341
3342 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
8def6eff 3343 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
44a07e3e 3344 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3345
3346 # Break up the prompt if it's really long.
3347 if ( length($self->prefix()) > 30 ) {
18b5b545 3348 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
22fc883d
SF
3349 $self->prefix("");
3350 $self->infix(":\t");
3351 }
3352 else {
3353 $self->infix("):\t");
3354 $self->position(
18b5b545 3355 $self->prefix . $line. $self->infix
44a07e3e 3356 . $self->_curr_line . $self->after
22fc883d
SF
3357 );
3358 }
3359
3360 # Print current line info, indenting if necessary.
18b5b545 3361 $self->_my_print_lineinfo($line, $self->position);
22fc883d 3362
44a07e3e
SF
3363 my $i;
3364 my $line_i = sub { return $DB::dbline[$i]; };
3365
22fc883d
SF
3366 # Scan forward, stopping at either the end or the next
3367 # unbreakable line.
18b5b545 3368 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
22fc883d
SF
3369 { #{ vi
3370
3371 # Drop out on null statements, block closers, and comments.
44a07e3e 3372 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
22fc883d
SF
3373
3374 # Drop out if the user interrupted us.
ebd0282e 3375 last if $signal;
22fc883d
SF
3376
3377 # Append a newline if the line doesn't have one. Can happen
3378 # in eval'ed text, for instance.
44a07e3e 3379 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3380
3381 # Next executable line.
44a07e3e 3382 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
22fc883d 3383 . $self->after;
8def6eff 3384 $self->append_to_position($incr_pos);
ad46ac70 3385 $self->_my_print_lineinfo($i, $incr_pos);
22fc883d
SF
3386 } ## end for ($i = $line + 1 ; $i...
3387 } ## end else [ if ($slave_editor)
3388
3389 return;
3390}
3391
174f9c5e 3392sub _handle_t_command {
9875a6d2
SF
3393 my $self = shift;
3394
3395 my $levels = $self->cmd_args();
3396
3397 if ((!length($levels)) or ($levels !~ /\D/)) {
931ac036 3398 $trace ^= 1;
174f9c5e 3399 local $\ = '';
8ad70697
SF
3400 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3401 print {$OUT} "Trace = "
931ac036 3402 . ( ( $trace & 1 )
174f9c5e
SF
3403 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3404 : "off" ) . "\n";
3405 next CMD;
3406 }
3407
3408 return;
3409}
3410
9d0b71b3
SF
3411
3412sub _handle_S_command {
3249b113
SF
3413 my $self = shift;
3414
9d0b71b3 3415 if (my ($print_all_subs, $should_reverse, $Spatt)
3249b113 3416 = $self->cmd_args =~ /\A((!)?(.+))?\z/) {
9d0b71b3
SF
3417 # $Spatt is the pattern (if any) to use.
3418 # Reverse scan?
3419 my $Srev = defined $should_reverse;
3420 # No args - print all subs.
3421 my $Snocheck = !defined $print_all_subs;
3422
3423 # Need to make these sane here.
3424 local $\ = '';
3425 local $, = '';
3426
3427 # Search through the debugger's magical hash of subs.
3428 # If $nocheck is true, just print the sub name.
3429 # Otherwise, check it against the pattern. We then use
3430 # the XOR trick to reverse the condition as required.
3431 foreach $subname ( sort( keys %sub ) ) {
3432 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3433 print $OUT $subname, "\n";
3434 }
3435 }
3436 next CMD;
3437 }
3438
3439 return;
3440}
3441
1ce985d2 3442sub _handle_V_command_and_X_command {
601c6a23 3443 my $self = shift;
1ce985d2
SF
3444
3445 $DB::cmd =~ s/^X\b/V $DB::package/;
3446
3447 # Bare V commands get the currently-being-debugged package
3448 # added.
601c6a23 3449 if ($self->_is_full('V')) {
1ce985d2
SF
3450 $DB::cmd = "V $DB::package";
3451 }
3452
3453 # V - show variables in package.
3454 if (my ($new_packname, $new_vars_str) =
3455 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3456
3457 # Save the currently selected filehandle and
3458 # force output to debugger's filehandle (dumpvar
3459 # just does "print" for output).
3460 my $savout = select($OUT);
3461
3462 # Grab package name and variables to dump.
3463 $packname = $new_packname;
3464 my @vars = split( ' ', $new_vars_str );
3465
3466 # If main::dumpvar isn't here, get it.
3467 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3468 if ( defined &main::dumpvar ) {
3469
3470 # We got it. Turn off subroutine entry/exit messages
3471 # for the moment, along with return values.
3472 local $frame = 0;
3473 local $doret = -2;
3474
3475 # must detect sigpipe failures - not catching
3476 # then will cause the debugger to die.
3477 eval {
b0b8faca 3478 main::dumpvar(
1ce985d2
SF
3479 $packname,
3480 defined $option{dumpDepth}
3481 ? $option{dumpDepth}
3482 : -1, # assume -1 unless specified
3483 @vars
3484 );
3485 };
3486
3487 # The die doesn't need to include the $@, because
3488 # it will automatically get propagated for us.
3489 if ($@) {
3490 die unless $@ =~ /dumpvar print failed/;
3491 }
3492 } ## end if (defined &main::dumpvar)
3493 else {
3494
3495 # Couldn't load dumpvar.
3496 print $OUT "dumpvar.pl not available.\n";
3497 }
3498
3499 # Restore the output filehandle, and go round again.
3500 select($savout);
3501 next CMD;
3502 }
3503
3504 return;
3505}
3506
d1450c23 3507sub _handle_dash_command {
601c6a23 3508 my $self = shift;
d1450c23 3509
601c6a23 3510 if ($self->_is_full('-')) {
d1450c23
SF
3511
3512 # back up by a window; go to 1 if back too far.
3513 $start -= $incr + $window + 1;
3514 $start = 1 if $start <= 0;
3515 $incr = $window - 1;
3516
3517 # Generate and execute a "l +" command (handled below).
3518 $DB::cmd = 'l ' . ($start) . '+';
fbe9ebae 3519 redo CMD;
d1450c23
SF
3520 }
3521 return;
3522}
3523
cb9d1513
SF
3524sub _n_or_s_commands_generic {
3525 my ($self, $new_val) = @_;
73c5e526 3526 # n - next
cb9d1513 3527 next CMD if DB::_DB__is_finished();
73c5e526 3528
cb9d1513
SF
3529 # Single step, but don't enter subs.
3530 $single = $new_val;
3531
3532 # Save for empty command (repeat last).
3533 $laststep = $DB::cmd;
3534 last CMD;
3535}
73c5e526 3536
cb9d1513
SF
3537sub _n_or_s {
3538 my ($self, $letter, $new_val) = @_;
3539
601c6a23 3540 if ($self->_is_full($letter)) {
cb9d1513 3541 $self->_n_or_s_commands_generic($new_val);
73c5e526 3542 }
a30f63cd 3543 else {
50a8a759
SF
3544 $self->_n_or_s_and_arg_commands_generic($letter, $new_val);
3545 }
73c5e526
SF
3546
3547 return;
3548}
3549
cb9d1513
SF
3550sub _handle_n_command {
3551 my $self = shift;
3552
3553 return $self->_n_or_s('n', 2);
3554}
3555
3556sub _handle_s_command {
3557 my $self = shift;
3558
3559 return $self->_n_or_s('s', 1);
3560}
3561
573b5003
SF
3562sub _handle_r_command {
3563 my $self = shift;
f89bf53e 3564
573b5003 3565 # r - return from the current subroutine.
601c6a23 3566 if ($self->_is_full('r')) {
573b5003
SF
3567
3568 # Can't do anything if the program's over.
3569 next CMD if DB::_DB__is_finished();
3570
3571 # Turn on stack trace.
3572 $stack[$stack_depth] |= 1;
3573
3574 # Print return value unless the stack is empty.
3575 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3576 last CMD;
3577 }
3578
3579 return;
3580}
3581
d4038e14 3582sub _handle_T_command {
601c6a23
SF
3583 my $self = shift;
3584
3585 if ($self->_is_full('T')) {
d4038e14
SF
3586 DB::print_trace( $OUT, 1 ); # skip DB
3587 next CMD;
3588 }
3589
3590 return;
3591}
3592
b6e88520 3593sub _handle_w_command {
9875a6d2
SF
3594 my $self = shift;
3595
3596 DB::cmd_w( 'w', $self->cmd_args() );
3597 next CMD;
b6e88520
SF
3598
3599 return;
3600}
3601
25953301 3602sub _handle_W_command {
a523ec7c
SF
3603 my $self = shift;
3604
3605 if (my $arg = $self->cmd_args) {
25953301
SF
3606 DB::cmd_W( 'W', $arg );
3607 next CMD;
3608 }
3609
3610 return;
3611}
3612
14f38b27
SF
3613sub _handle_rc_recall_command {
3614 my $self = shift;
3615
3616 # $rc - recall command.
3617 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3618
3619 # No arguments, take one thing off history.
3620 pop(@hist) if length($DB::cmd) > 1;
3621
3622 # Relative (- found)?
3623 # Y - index back from most recent (by 1 if bare minus)
3624 # N - go to that particular command slot or the last
3625 # thing if nothing following.
14f38b27 3626
9c6fceaf
SF
3627 $self->cmd_verb(
3628 scalar($minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist ))
3629 );
14f38b27
SF
3630
3631 # Pick out the command desired.
610f01b9 3632 $DB::cmd = $hist[$self->cmd_verb];
14f38b27
SF
3633
3634 # Print the command to be executed and restart the loop
3635 # with that command in the buffer.
3636 print {$OUT} $DB::cmd, "\n";
3637 redo CMD;
3638 }
3639
3640 return;
3641}
3642
0d2c714c
SF
3643sub _handle_rc_search_history_command {
3644 my $self = shift;
3645
3646 # $rc pattern $rc - find a command in the history.
3647 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) {
3648
3649 # Create the pattern to use.
3650 my $pat = "^$arg";
3651 $self->pat($pat);
3652
3653 # Toss off last entry if length is >1 (and it always is).
3654 pop(@hist) if length($DB::cmd) > 1;
3655
9c6fceaf 3656 my $i;
0d2c714c
SF
3657
3658 # Look backward through the history.
3659 SEARCH_HIST:
3660 for ( $i = $#hist ; $i ; --$i ) {
3661 # Stop if we find it.
3662 last SEARCH_HIST if $hist[$i] =~ /$pat/;
3663 }
3664
9c6fceaf 3665 if ( !$i ) {
0d2c714c
SF
3666
3667 # Never found it.
3668 print $OUT "No such command!\n\n";
3669 next CMD;
3670 }
3671
3672 # Found it. Put it in the buffer, print it, and process it.
9c6fceaf 3673 $DB::cmd = $hist[$i];
0d2c714c
SF
3674 print $OUT $DB::cmd, "\n";
3675 redo CMD;
3676 }
b6aeebb8
SF
3677
3678 return;
0d2c714c
SF
3679}
3680
0664c09a
SF
3681sub _handle_H_command {
3682 my $self = shift;
3683
3249b113 3684 if ($self->cmd_args =~ m#\A\*#) {
0664c09a
SF
3685 @hist = @truehist = ();
3686 print $OUT "History cleansed\n";
3687 next CMD;
3688 }
3689
3249b113 3690 if (my ($num) = $self->cmd_args =~ /\A(?:-(\d+))?/) {
0664c09a
SF
3691
3692 # Anything other than negative numbers is ignored by
3693 # the (incorrect) pattern, so this test does nothing.
3694 $end = $num ? ( $#hist - $num ) : 0;
3695
3696 # Set to the minimum if less than zero.
3697 $hist = 0 if $hist < 0;
3698
3699 # Start at the end of the array.
3700 # Stay in while we're still above the ending value.
3701 # Tick back by one each time around the loop.
3702 my $i;
3703
3704 for ( $i = $#hist ; $i > $end ; $i-- ) {
3705
3706 # Print the command unless it has no arguments.
3707 print $OUT "$i: ", $hist[$i], "\n"
3708 unless $hist[$i] =~ /^.?$/;
3709 }
3710
0664c09a
SF
3711 next CMD;
3712 }
3713
3714 return;
3715}
3716
c7b0c61d
SF
3717sub _handle_doc_command {
3718 my $self = shift;
3719
3720 # man, perldoc, doc - show manual pages.
3721 if (my ($man_page)
3722 = $DB::cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
b019bbd2 3723 DB::runman($man_page);
c7b0c61d
SF
3724 next CMD;
3725 }
3726
3727 return;
3728}
3729
b6aeebb8
SF
3730sub _handle_p_command {
3731 my $self = shift;
3732
3733 my $print_cmd = 'print {$DB::OUT} ';
3734 # p - print (no args): print $_.
601c6a23 3735 if ($self->_is_full('p')) {
b6aeebb8
SF
3736 $DB::cmd = $print_cmd . '$_';
3737 }
a30f63cd
SF
3738 else {
3739 # p - print the given expression.