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Fix for RT #118169
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e22ea7cc 1
b570d64b 2=head1 NAME
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be9a9b1d 4perl5db.pl - the perl debugger
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5
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
2dbd01ad 515BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
9eba6a4e 516
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517BEGIN {
518 require feature;
519 $^V =~ /^v(\d+\.\d+)/;
520 feature->import(":$1");
521}
522
54d04a52 523# Debugger for Perl 5.00x; perl5db.pl patch level:
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524use vars qw($VERSION $header);
525
1799399c 526$VERSION = '1.40';
69893cff 527
e22ea7cc 528$header = "perl5db.pl version $VERSION";
d338d6fe 529
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530=head1 DEBUGGER ROUTINES
531
532=head2 C<DB::eval()>
533
534This function replaces straight C<eval()> inside the debugger; it simplifies
535the process of evaluating code in the user's context.
536
b570d64b 537The code to be evaluated is passed via the package global variable
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538C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
539
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540Before we do the C<eval()>, we preserve the current settings of C<$trace>,
541C<$single>, C<$^D> and C<$usercontext>. The latter contains the
542preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
543user's current package, grabbed when C<DB::DB> got control. This causes the
544proper context to be used when the eval is actually done. Afterward, we
545restore C<$trace>, C<$single>, and C<$^D>.
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546
547Next we need to handle C<$@> without getting confused. We save C<$@> in a
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548local lexical, localize C<$saved[0]> (which is where C<save()> will put
549C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
69893cff 550C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
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551considered sane by the debugger. If there was an C<eval()> error, we print
552it on the debugger's output. If C<$onetimedump> is defined, we call
553C<dumpit> if it's set to 'dump', or C<methods> if it's set to
554'methods'. Setting it to something else causes the debugger to do the eval
555but not print the result - handy if you want to do something else with it
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556(the "watch expressions" code does this to get the value of the watch
557expression but not show it unless it matters).
558
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559In any case, we then return the list of output from C<eval> to the caller,
560and unwinding restores the former version of C<$@> in C<@saved> as well
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561(the localization of C<$saved[0]> goes away at the end of this scope).
562
563=head3 Parameters and variables influencing execution of DB::eval()
564
565C<DB::eval> isn't parameterized in the standard way; this is to keep the
566debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
b570d64b 567The variables listed below influence C<DB::eval()>'s execution directly.
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568
569=over 4
570
571=item C<$evalarg> - the thing to actually be eval'ed
572
be9a9b1d 573=item C<$trace> - Current state of execution tracing
69893cff 574
be9a9b1d 575=item C<$single> - Current state of single-stepping
69893cff 576
b570d64b 577=item C<$onetimeDump> - what is to be displayed after the evaluation
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578
579=item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
580
581=back
582
583The following variables are altered by C<DB::eval()> during its execution. They
b570d64b 584are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
69893cff
RGS
585
586=over 4
587
588=item C<@res> - used to capture output from actual C<eval>.
589
590=item C<$otrace> - saved value of C<$trace>.
591
b570d64b 592=item C<$osingle> - saved value of C<$single>.
69893cff
RGS
593
594=item C<$od> - saved value of C<$^D>.
595
596=item C<$saved[0]> - saved value of C<$@>.
597
b570d64b 598=item $\ - for output of C<$@> if there is an evaluation error.
69893cff
RGS
599
600=back
601
602=head3 The problem of lexicals
603
604The context of C<DB::eval()> presents us with some problems. Obviously,
605we want to be 'sandboxed' away from the debugger's internals when we do
606the eval, but we need some way to control how punctuation variables and
b570d64b 607debugger globals are used.
69893cff
RGS
608
609We can't use local, because the code inside C<DB::eval> can see localized
610variables; and we can't use C<my> either for the same reason. The code
611in this routine compromises and uses C<my>.
612
613After this routine is over, we don't have user code executing in the debugger's
614context, so we can use C<my> freely.
615
616=cut
617
618############################################## Begin lexical danger zone
619
620# 'my' variables used here could leak into (that is, be visible in)
621# the context that the code being evaluated is executing in. This means that
622# the code could modify the debugger's variables.
623#
624# Fiddling with the debugger's context could be Bad. We insulate things as
625# much as we can.
626
6b24a4b7
SF
627use vars qw(
628 @args
629 %break_on_load
6b24a4b7
SF
630 $CommandSet
631 $CreateTTY
632 $DBGR
633 @dbline
634 $dbline
635 %dbline
636 $dieLevel
6b24a4b7 637 $filename
6b24a4b7
SF
638 $histfile
639 $histsize
6b24a4b7
SF
640 $IN
641 $inhibit_exit
642 @ini_INC
643 $ini_warn
6b24a4b7
SF
644 $maxtrace
645 $od
6b24a4b7
SF
646 @options
647 $osingle
648 $otrace
6b24a4b7
SF
649 $pager
650 $post
651 %postponed
652 $prc
653 $pre
654 $pretype
655 $psh
656 @RememberOnROptions
657 $remoteport
658 @res
659 $rl
660 @saved
6b24a4b7 661 $signalLevel
6b24a4b7 662 $sub
6b24a4b7 663 $term
6b24a4b7
SF
664 $usercontext
665 $warnLevel
6b24a4b7
SF
666);
667
0b83f3d9 668our (
2ef1dcdb 669 @cmdfhs,
0b83f3d9
SF
670 $evalarg,
671 $frame,
0664c09a 672 $hist,
0b83f3d9
SF
673 $ImmediateStop,
674 $line,
675 $onetimeDump,
b8d11fe0 676 $onetimedumpDepth,
1ce985d2 677 %option,
0b83f3d9 678 $OUT,
1ce985d2 679 $packname,
0b83f3d9
SF
680 $signal,
681 $single,
d1450c23 682 $start,
9d0b71b3
SF
683 %sub,
684 $subname,
0b83f3d9 685 $trace,
d1450c23 686 $window,
18b5b545 687);
931ac036 688
6b24a4b7
SF
689# Used to save @ARGV and extract any debugger-related flags.
690use vars qw(@ARGS);
691
692# Used to prevent multiple entries to diesignal()
693# (if for instance diesignal() itself dies)
694use vars qw($panic);
695
696# Used to prevent the debugger from running nonstop
697# after a restart
ebd0282e 698our ($second_time);
6b24a4b7
SF
699
700sub _calc_usercontext {
701 my ($package) = @_;
702
703 # Cancel strict completely for the evaluated code, so the code
704 # the user evaluates won't be affected by it. (Shlomi Fish)
22fc883d 705 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
6b24a4b7
SF
706 . "package $package;"; # this won't let them modify, alas
707}
708
c1051fcf 709sub eval {
69893cff 710
c1051fcf 711 # 'my' would make it visible from user code
e22ea7cc 712 # but so does local! --tchrist
69893cff 713 # Remember: this localizes @DB::res, not @main::res.
c1051fcf
IZ
714 local @res;
715 {
e22ea7cc
RF
716
717 # Try to keep the user code from messing with us. Save these so that
718 # even if the eval'ed code changes them, we can put them back again.
719 # Needed because the user could refer directly to the debugger's
69893cff
RGS
720 # package globals (and any 'my' variables in this containing scope)
721 # inside the eval(), and we want to try to stay safe.
e22ea7cc 722 local $otrace = $trace;
69893cff
RGS
723 local $osingle = $single;
724 local $od = $^D;
725
726 # Untaint the incoming eval() argument.
727 { ($evalarg) = $evalarg =~ /(.*)/s; }
728
e22ea7cc 729 # $usercontext built in DB::DB near the comment
69893cff
RGS
730 # "set up the context for DB::eval ..."
731 # Evaluate and save any results.
e22ea7cc 732 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
69893cff
RGS
733
734 # Restore those old values.
735 $trace = $otrace;
736 $single = $osingle;
737 $^D = $od;
c1051fcf 738 }
69893cff
RGS
739
740 # Save the current value of $@, and preserve it in the debugger's copy
741 # of the saved precious globals.
c1051fcf 742 my $at = $@;
69893cff
RGS
743
744 # Since we're only saving $@, we only have to localize the array element
745 # that it will be stored in.
e22ea7cc 746 local $saved[0]; # Preserve the old value of $@
e3d167f6 747 eval { &DB::save };
69893cff
RGS
748
749 # Now see whether we need to report an error back to the user.
c1051fcf 750 if ($at) {
69893cff
RGS
751 local $\ = '';
752 print $OUT $at;
753 }
754
755 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
756 # are package globals.
757 elsif ($onetimeDump) {
e22ea7cc
RF
758 if ( $onetimeDump eq 'dump' ) {
759 local $option{dumpDepth} = $onetimedumpDepth
760 if defined $onetimedumpDepth;
761 dumpit( $OUT, \@res );
762 }
763 elsif ( $onetimeDump eq 'methods' ) {
764 methods( $res[0] );
765 }
69893cff 766 } ## end elsif ($onetimeDump)
c1051fcf 767 @res;
69893cff
RGS
768} ## end sub eval
769
770############################################## End lexical danger zone
c1051fcf 771
e22ea7cc
RF
772# After this point it is safe to introduce lexicals.
773# The code being debugged will be executing in its own context, and
69893cff 774# can't see the inside of the debugger.
d338d6fe 775#
e22ea7cc 776# However, one should not overdo it: leave as much control from outside as
69893cff
RGS
777# possible. If you make something a lexical, it's not going to be addressable
778# from outside the debugger even if you know its name.
779
d338d6fe
PP
780# This file is automatically included if you do perl -d.
781# It's probably not useful to include this yourself.
782#
e22ea7cc 783# Before venturing further into these twisty passages, it is
2f7e9187
MS
784# wise to read the perldebguts man page or risk the ire of dragons.
785#
69893cff
RGS
786# (It should be noted that perldebguts will tell you a lot about
787# the underlying mechanics of how the debugger interfaces into the
788# Perl interpreter, but not a lot about the debugger itself. The new
789# comments in this code try to address this problem.)
790
d338d6fe 791# Note that no subroutine call is possible until &DB::sub is defined
36477c24 792# (for subroutines defined outside of the package DB). In fact the same is
d338d6fe 793# true if $deep is not defined.
055fd3a9
GS
794
795# Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
055fd3a9
GS
796
797# modified Perl debugger, to be run from Emacs in perldb-mode
798# Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
799# Johan Vromans -- upgrade to 4.0 pl 10
800# Ilya Zakharevich -- patches after 5.001 (and some before ;-)
6fae1ad7 801########################################################################
d338d6fe 802
69893cff
RGS
803=head1 DEBUGGER INITIALIZATION
804
805The debugger starts up in phases.
806
807=head2 BASIC SETUP
808
809First, it initializes the environment it wants to run in: turning off
810warnings during its own compilation, defining variables which it will need
811to avoid warnings later, setting itself up to not exit when the program
812terminates, and defaulting to printing return values for the C<r> command.
813
814=cut
815
eda6e075 816# Needed for the statement after exec():
69893cff
RGS
817#
818# This BEGIN block is simply used to switch off warnings during debugger
98dc9551 819# compilation. Probably it would be better practice to fix the warnings,
69893cff 820# but this is how it's done at the moment.
eda6e075 821
e22ea7cc
RF
822BEGIN {
823 $ini_warn = $^W;
824 $^W = 0;
825} # Switch compilation warnings off until another BEGIN.
d12a4851 826
69893cff
RGS
827local ($^W) = 0; # Switch run-time warnings off during init.
828
2cbb2ee1
RGS
829=head2 THREADS SUPPORT
830
831If we are running under a threaded Perl, we require threads and threads::shared
832if the environment variable C<PERL5DB_THREADED> is set, to enable proper
833threaded debugger control. C<-dt> can also be used to set this.
834
835Each new thread will be announced and the debugger prompt will always inform
836you of each new thread created. It will also indicate the thread id in which
837we are currently running within the prompt like this:
838
2dbd01ad 839 [tid] DB<$i>
2cbb2ee1
RGS
840
841Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
842command prompt. The prompt will show: C<[0]> when running under threads, but
843not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
844
845While running under threads, when you set or delete a breakpoint (etc.), this
b570d64b 846will apply to all threads, not just the currently running one. When you are
2cbb2ee1
RGS
847in a currently executing thread, you will stay there until it completes. With
848the current implementation it is not currently possible to hop from one thread
849to another.
850
851The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
852
853Note that threading support was built into the debugger as of Perl version
854C<5.8.6> and debugger version C<1.2.8>.
855
856=cut
857
858BEGIN {
2dbd01ad
SF
859 # ensure we can share our non-threaded variables or no-op
860 if ($ENV{PERL5DB_THREADED}) {
861 require threads;
862 require threads::shared;
863 import threads::shared qw(share);
864 $DBGR;
865 share(\$DBGR);
866 lock($DBGR);
867 print "Threads support enabled\n";
868 } else {
cde405a6 869 *share = sub(\[$@%]) {};
2dbd01ad 870 }
2cbb2ee1
RGS
871}
872
2218c045
SF
873# These variables control the execution of 'dumpvar.pl'.
874{
875 package dumpvar;
876 use vars qw(
877 $hashDepth
878 $arrayDepth
879 $dumpDBFiles
880 $dumpPackages
881 $quoteHighBit
882 $printUndef
883 $globPrint
884 $usageOnly
885 );
886}
69893cff 887
2218c045
SF
888# used to control die() reporting in diesignal()
889{
890 package Carp;
891 use vars qw($CarpLevel);
892}
d338d6fe 893
422c59bf 894# without threads, $filename is not defined until DB::DB is called
cde405a6 895share($main::{'_<'.$filename}) if defined $filename;
2cbb2ee1 896
54d04a52 897# Command-line + PERLLIB:
69893cff 898# Save the contents of @INC before they are modified elsewhere.
54d04a52
IZ
899@ini_INC = @INC;
900
69893cff
RGS
901# This was an attempt to clear out the previous values of various
902# trapped errors. Apparently it didn't help. XXX More info needed!
d338d6fe
PP
903# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
904
69893cff
RGS
905# We set these variables to safe values. We don't want to blindly turn
906# off warnings, because other packages may still want them.
e22ea7cc
RF
907$trace = $signal = $single = 0; # Uninitialized warning suppression
908 # (local $^W cannot help - other packages!).
69893cff
RGS
909
910# Default to not exiting when program finishes; print the return
911# value when the 'r' command is used to return from a subroutine.
55497cff 912$inhibit_exit = $option{PrintRet} = 1;
d338d6fe 913
6b24a4b7
SF
914use vars qw($trace_to_depth);
915
5e2b42dd
SF
916# Default to 1E9 so it won't be limited to a certain recursion depth.
917$trace_to_depth = 1E9;
bdba49ad 918
69893cff
RGS
919=head1 OPTION PROCESSING
920
b570d64b
SF
921The debugger's options are actually spread out over the debugger itself and
922C<dumpvar.pl>; some of these are variables to be set, while others are
69893cff
RGS
923subs to be called with a value. To try to make this a little easier to
924manage, the debugger uses a few data structures to define what options
925are legal and how they are to be processed.
926
927First, the C<@options> array defines the I<names> of all the options that
928are to be accepted.
929
930=cut
931
932@options = qw(
5561b870 933 CommandSet HistFile HistSize
e22ea7cc
RF
934 hashDepth arrayDepth dumpDepth
935 DumpDBFiles DumpPackages DumpReused
936 compactDump veryCompact quote
937 HighBit undefPrint globPrint
938 PrintRet UsageOnly frame
939 AutoTrace TTY noTTY
940 ReadLine NonStop LineInfo
941 maxTraceLen recallCommand ShellBang
942 pager tkRunning ornaments
943 signalLevel warnLevel dieLevel
944 inhibit_exit ImmediateStop bareStringify
945 CreateTTY RemotePort windowSize
584420f0 946 DollarCaretP
e22ea7cc 947);
d12a4851 948
584420f0 949@RememberOnROptions = qw(DollarCaretP);
d12a4851 950
69893cff
RGS
951=pod
952
953Second, C<optionVars> lists the variables that each option uses to save its
954state.
955
956=cut
957
6b24a4b7
SF
958use vars qw(%optionVars);
959
69893cff 960%optionVars = (
e22ea7cc
RF
961 hashDepth => \$dumpvar::hashDepth,
962 arrayDepth => \$dumpvar::arrayDepth,
963 CommandSet => \$CommandSet,
964 DumpDBFiles => \$dumpvar::dumpDBFiles,
965 DumpPackages => \$dumpvar::dumpPackages,
966 DumpReused => \$dumpvar::dumpReused,
967 HighBit => \$dumpvar::quoteHighBit,
968 undefPrint => \$dumpvar::printUndef,
969 globPrint => \$dumpvar::globPrint,
970 UsageOnly => \$dumpvar::usageOnly,
971 CreateTTY => \$CreateTTY,
972 bareStringify => \$dumpvar::bareStringify,
973 frame => \$frame,
974 AutoTrace => \$trace,
975 inhibit_exit => \$inhibit_exit,
976 maxTraceLen => \$maxtrace,
977 ImmediateStop => \$ImmediateStop,
978 RemotePort => \$remoteport,
979 windowSize => \$window,
5561b870
AK
980 HistFile => \$histfile,
981 HistSize => \$histsize,
69893cff
RGS
982);
983
984=pod
985
986Third, C<%optionAction> defines the subroutine to be called to process each
987option.
988
b570d64b 989=cut
69893cff 990
6b24a4b7
SF
991use vars qw(%optionAction);
992
69893cff
RGS
993%optionAction = (
994 compactDump => \&dumpvar::compactDump,
995 veryCompact => \&dumpvar::veryCompact,
996 quote => \&dumpvar::quote,
997 TTY => \&TTY,
998 noTTY => \&noTTY,
999 ReadLine => \&ReadLine,
1000 NonStop => \&NonStop,
1001 LineInfo => \&LineInfo,
1002 recallCommand => \&recallCommand,
1003 ShellBang => \&shellBang,
1004 pager => \&pager,
1005 signalLevel => \&signalLevel,
1006 warnLevel => \&warnLevel,
1007 dieLevel => \&dieLevel,
1008 tkRunning => \&tkRunning,
1009 ornaments => \&ornaments,
1010 RemotePort => \&RemotePort,
1011 DollarCaretP => \&DollarCaretP,
d12a4851
JH
1012);
1013
69893cff
RGS
1014=pod
1015
1016Last, the C<%optionRequire> notes modules that must be C<require>d if an
1017option is used.
1018
1019=cut
d338d6fe 1020
69893cff
RGS
1021# Note that this list is not complete: several options not listed here
1022# actually require that dumpvar.pl be loaded for them to work, but are
1023# not in the table. A subsequent patch will correct this problem; for
1024# the moment, we're just recommenting, and we are NOT going to change
1025# function.
6b24a4b7
SF
1026use vars qw(%optionRequire);
1027
eda6e075 1028%optionRequire = (
69893cff
RGS
1029 compactDump => 'dumpvar.pl',
1030 veryCompact => 'dumpvar.pl',
1031 quote => 'dumpvar.pl',
e22ea7cc 1032);
69893cff
RGS
1033
1034=pod
1035
1036There are a number of initialization-related variables which can be set
1037by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1038variable. These are:
1039
1040=over 4
1041
1042=item C<$rl> - readline control XXX needs more explanation
1043
1044=item C<$warnLevel> - whether or not debugger takes over warning handling
1045
1046=item C<$dieLevel> - whether or not debugger takes over die handling
1047
1048=item C<$signalLevel> - whether or not debugger takes over signal handling
1049
1050=item C<$pre> - preprompt actions (array reference)
1051
1052=item C<$post> - postprompt actions (array reference)
1053
1054=item C<$pretype>
1055
1056=item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1057
1058=item C<$CommandSet> - which command set to use (defaults to new, documented set)
1059
1060=back
1061
1062=cut
d338d6fe
PP
1063
1064# These guys may be defined in $ENV{PERL5DB} :
69893cff
RGS
1065$rl = 1 unless defined $rl;
1066$warnLevel = 1 unless defined $warnLevel;
1067$dieLevel = 1 unless defined $dieLevel;
1068$signalLevel = 1 unless defined $signalLevel;
1069$pre = [] unless defined $pre;
1070$post = [] unless defined $post;
1071$pretype = [] unless defined $pretype;
1072$CreateTTY = 3 unless defined $CreateTTY;
1073$CommandSet = '580' unless defined $CommandSet;
1074
2cbb2ee1
RGS
1075share($rl);
1076share($warnLevel);
1077share($dieLevel);
1078share($signalLevel);
1079share($pre);
1080share($post);
1081share($pretype);
1082share($rl);
1083share($CreateTTY);
1084share($CommandSet);
1085
69893cff
RGS
1086=pod
1087
1088The default C<die>, C<warn>, and C<signal> handlers are set up.
1089
1090=cut
055fd3a9 1091
d338d6fe
PP
1092warnLevel($warnLevel);
1093dieLevel($dieLevel);
1094signalLevel($signalLevel);
055fd3a9 1095
69893cff
RGS
1096=pod
1097
1098The pager to be used is needed next. We try to get it from the
5561b870 1099environment first. If it's not defined there, we try to find it in
69893cff
RGS
1100the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1101then call the C<pager()> function to save the pager name.
1102
1103=cut
1104
1105# This routine makes sure $pager is set up so that '|' can use it.
4865a36d 1106pager(
e22ea7cc 1107
69893cff 1108 # If PAGER is defined in the environment, use it.
e22ea7cc
RF
1109 defined $ENV{PAGER}
1110 ? $ENV{PAGER}
69893cff
RGS
1111
1112 # If not, see if Config.pm defines it.
e22ea7cc
RF
1113 : eval { require Config }
1114 && defined $Config::Config{pager}
1115 ? $Config::Config{pager}
69893cff
RGS
1116
1117 # If not, fall back to 'more'.
e22ea7cc
RF
1118 : 'more'
1119 )
1120 unless defined $pager;
69893cff
RGS
1121
1122=pod
1123
1124We set up the command to be used to access the man pages, the command
be9a9b1d
AT
1125recall character (C<!> unless otherwise defined) and the shell escape
1126character (C<!> unless otherwise defined). Yes, these do conflict, and
69893cff
RGS
1127neither works in the debugger at the moment.
1128
1129=cut
1130
055fd3a9 1131setman();
69893cff
RGS
1132
1133# Set up defaults for command recall and shell escape (note:
1134# these currently don't work in linemode debugging).
2218c045
SF
1135recallCommand("!") unless defined $prc;
1136shellBang("!") unless defined $psh;
69893cff
RGS
1137
1138=pod
1139
1140We then set up the gigantic string containing the debugger help.
1141We also set the limit on the number of arguments we'll display during a
1142trace.
1143
1144=cut
1145
04e43a21 1146sethelp();
69893cff
RGS
1147
1148# If we didn't get a default for the length of eval/stack trace args,
1149# set it here.
1d06cb2d 1150$maxtrace = 400 unless defined $maxtrace;
69893cff
RGS
1151
1152=head2 SETTING UP THE DEBUGGER GREETING
1153
be9a9b1d 1154The debugger I<greeting> helps to inform the user how many debuggers are
69893cff
RGS
1155running, and whether the current debugger is the primary or a child.
1156
1157If we are the primary, we just hang onto our pid so we'll have it when
1158or if we start a child debugger. If we are a child, we'll set things up
1159so we'll have a unique greeting and so the parent will give us our own
1160TTY later.
1161
1162We save the current contents of the C<PERLDB_PIDS> environment variable
1163because we mess around with it. We'll also need to hang onto it because
1164we'll need it if we restart.
1165
1166Child debuggers make a label out of the current PID structure recorded in
1167PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1168yet so the parent will give them one later via C<resetterm()>.
1169
1170=cut
1171
e22ea7cc 1172# Save the current contents of the environment; we're about to
69893cff 1173# much with it. We'll need this if we have to restart.
6b24a4b7 1174use vars qw($ini_pids);
f1583d8f 1175$ini_pids = $ENV{PERLDB_PIDS};
69893cff 1176
6b24a4b7
SF
1177use vars qw ($pids $term_pid);
1178
e22ea7cc
RF
1179if ( defined $ENV{PERLDB_PIDS} ) {
1180
69893cff 1181 # We're a child. Make us a label out of the current PID structure
e22ea7cc 1182 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
69893cff 1183 # a term yet so the parent will give us one later via resetterm().
55f4245e
JM
1184
1185 my $env_pids = $ENV{PERLDB_PIDS};
1186 $pids = "[$env_pids]";
1187
1188 # Unless we are on OpenVMS, all programs under the DCL shell run under
1189 # the same PID.
1190
1191 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1192 $term_pid = $$;
1193 }
1194 else {
1195 $ENV{PERLDB_PIDS} .= "->$$";
1196 $term_pid = -1;
1197 }
1198
69893cff
RGS
1199} ## end if (defined $ENV{PERLDB_PIDS...
1200else {
e22ea7cc
RF
1201
1202 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
69893cff
RGS
1203 # child debugger, and mark us as the parent, so we'll know to set up
1204 # more TTY's is we have to.
1205 $ENV{PERLDB_PIDS} = "$$";
619a0444 1206 $pids = "[pid=$$]";
e22ea7cc 1207 $term_pid = $$;
f1583d8f 1208}
69893cff 1209
6b24a4b7 1210use vars qw($pidprompt);
f1583d8f 1211$pidprompt = '';
69893cff
RGS
1212
1213# Sets up $emacs as a synonym for $slave_editor.
7793e5c2 1214our ($slave_editor);
69893cff
RGS
1215*emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1216
1217=head2 READING THE RC FILE
1218
b570d64b 1219The debugger will read a file of initialization options if supplied. If
69893cff
RGS
1220running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1221
b570d64b 1222=cut
69893cff
RGS
1223
1224# As noted, this test really doesn't check accurately that the debugger
1225# is running at a terminal or not.
d338d6fe 1226
6b24a4b7 1227use vars qw($rcfile);
fb4d8a6c
SF
1228{
1229 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1230 # this is the wrong metric!
1231 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
d338d6fe
PP
1232}
1233
69893cff
RGS
1234=pod
1235
1236The debugger does a safety test of the file to be read. It must be owned
1237either by the current user or root, and must only be writable by the owner.
1238
1239=cut
1240
1241# This wraps a safety test around "do" to read and evaluate the init file.
1242#
055fd3a9
GS
1243# This isn't really safe, because there's a race
1244# between checking and opening. The solution is to
1245# open and fstat the handle, but then you have to read and
1246# eval the contents. But then the silly thing gets
69893cff
RGS
1247# your lexical scope, which is unfortunate at best.
1248sub safe_do {
055fd3a9
GS
1249 my $file = shift;
1250
1251 # Just exactly what part of the word "CORE::" don't you understand?
69893cff
RGS
1252 local $SIG{__WARN__};
1253 local $SIG{__DIE__};
055fd3a9 1254
e22ea7cc 1255 unless ( is_safe_file($file) ) {
69893cff 1256 CORE::warn <<EO_GRIPE;
055fd3a9 1257perldb: Must not source insecure rcfile $file.
b570d64b 1258 You or the superuser must be the owner, and it must not
69893cff 1259 be writable by anyone but its owner.
055fd3a9 1260EO_GRIPE
69893cff
RGS
1261 return;
1262 } ## end unless (is_safe_file($file...
055fd3a9
GS
1263
1264 do $file;
1265 CORE::warn("perldb: couldn't parse $file: $@") if $@;
69893cff 1266} ## end sub safe_do
055fd3a9 1267
69893cff
RGS
1268# This is the safety test itself.
1269#
055fd3a9
GS
1270# Verifies that owner is either real user or superuser and that no
1271# one but owner may write to it. This function is of limited use
1272# when called on a path instead of upon a handle, because there are
1273# no guarantees that filename (by dirent) whose file (by ino) is
e22ea7cc 1274# eventually accessed is the same as the one tested.
055fd3a9
GS
1275# Assumes that the file's existence is not in doubt.
1276sub is_safe_file {
1277 my $path = shift;
69893cff 1278 stat($path) || return; # mysteriously vaporized
e22ea7cc 1279 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
055fd3a9
GS
1280
1281 return 0 if $uid != 0 && $uid != $<;
1282 return 0 if $mode & 022;
1283 return 1;
69893cff 1284} ## end sub is_safe_file
055fd3a9 1285
69893cff 1286# If the rcfile (whichever one we decided was the right one to read)
e22ea7cc
RF
1287# exists, we safely do it.
1288if ( -f $rcfile ) {
055fd3a9 1289 safe_do("./$rcfile");
69893cff 1290}
e22ea7cc 1291
69893cff 1292# If there isn't one here, try the user's home directory.
e22ea7cc 1293elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
055fd3a9
GS
1294 safe_do("$ENV{HOME}/$rcfile");
1295}
e22ea7cc 1296
69893cff 1297# Else try the login directory.
e22ea7cc 1298elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
055fd3a9 1299 safe_do("$ENV{LOGDIR}/$rcfile");
d338d6fe
PP
1300}
1301
69893cff 1302# If the PERLDB_OPTS variable has options in it, parse those out next.
e22ea7cc
RF
1303if ( defined $ENV{PERLDB_OPTS} ) {
1304 parse_options( $ENV{PERLDB_OPTS} );
d338d6fe
PP
1305}
1306
69893cff
RGS
1307=pod
1308
1309The last thing we do during initialization is determine which subroutine is
1310to be used to obtain a new terminal when a new debugger is started. Right now,
b0b54b5e 1311the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
11653f7f 1312(darwin).
69893cff
RGS
1313
1314=cut
1315
1316# Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1317# Works if you're running an xterm or xterm-like window, or you're on
6fae1ad7
RF
1318# OS/2, or on Mac OS X. This may need some expansion.
1319
1320if (not defined &get_fork_TTY) # only if no routine exists
69893cff 1321{
b570d64b 1322 if ( defined $remoteport ) {
11653f7f
JJ
1323 # Expect an inetd-like server
1324 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1325 }
1326 elsif (defined $ENV{TERM} # If we know what kind
6fae1ad7
RF
1327 # of terminal this is,
1328 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1329 and defined $ENV{DISPLAY} # and what display it's on,
1330 )
1331 {
1332 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1333 }
1334 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1335 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1336 }
1337 elsif ( $^O eq 'darwin' # If this is Mac OS X
1338 and defined $ENV{TERM_PROGRAM} # and we're running inside
1339 and $ENV{TERM_PROGRAM}
1340 eq 'Apple_Terminal' # Terminal.app
1341 )
1342 {
1343 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1344 }
69893cff 1345} ## end if (not defined &get_fork_TTY...
e22ea7cc 1346
dbb46cec
DQ
1347# untaint $^O, which may have been tainted by the last statement.
1348# see bug [perl #24674]
e22ea7cc
RF
1349$^O =~ m/^(.*)\z/;
1350$^O = $1;
f1583d8f 1351
d12a4851 1352# Here begin the unreadable code. It needs fixing.
055fd3a9 1353
69893cff
RGS
1354=head2 RESTART PROCESSING
1355
1356This section handles the restart command. When the C<R> command is invoked, it
1357tries to capture all of the state it can into environment variables, and
1358then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1359if C<PERLDB_RESTART> is there; if so, we reload all the information that
1360the R command stuffed into the environment variables.
1361
b570d64b 1362 PERLDB_RESTART - flag only, contains no restart data itself.
69893cff
RGS
1363 PERLDB_HIST - command history, if it's available
1364 PERLDB_ON_LOAD - breakpoints set by the rc file
1365 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1366 PERLDB_VISITED - files that had breakpoints
1367 PERLDB_FILE_... - breakpoints for a file
1368 PERLDB_OPT - active options
1369 PERLDB_INC - the original @INC
1370 PERLDB_PRETYPE - preprompt debugger actions
1371 PERLDB_PRE - preprompt Perl code
1372 PERLDB_POST - post-prompt Perl code
1373 PERLDB_TYPEAHEAD - typeahead captured by readline()
1374
1375We chug through all these variables and plug the values saved in them
1376back into the appropriate spots in the debugger.
1377
1378=cut
1379
0664c09a 1380use vars qw(%postponed_file @typeahead);
14f38b27 1381
0664c09a 1382our (@hist, @truehist);
6b24a4b7 1383
fb0fb5f4
SF
1384sub _restore_shared_globals_after_restart
1385{
1386 @hist = get_list('PERLDB_HIST');
1387 %break_on_load = get_list("PERLDB_ON_LOAD");
1388 %postponed = get_list("PERLDB_POSTPONE");
1389
1390 share(@hist);
1391 share(@truehist);
1392 share(%break_on_load);
1393 share(%postponed);
1394}
1395
e18a02a6 1396sub _restore_breakpoints_and_actions {
e22ea7cc 1397
e22ea7cc 1398 my @had_breakpoints = get_list("PERLDB_VISITED");
e18a02a6 1399
bdba49ad
SF
1400 for my $file_idx ( 0 .. $#had_breakpoints ) {
1401 my $filename = $had_breakpoints[$file_idx];
1402 my %pf = get_list("PERLDB_FILE_$file_idx");
1403 $postponed_file{ $filename } = \%pf if %pf;
1404 my @lines = sort {$a <=> $b} keys(%pf);
1405 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1406 for my $line_idx (0 .. $#lines) {
1407 _set_breakpoint_enabled_status(
1408 $filename,
1409 $lines[$line_idx],
1410 ($enabled_statuses[$line_idx] ? 1 : ''),
1411 );
1412 }
e22ea7cc 1413 }
69893cff 1414
e18a02a6
SF
1415 return;
1416}
1417
ca50076b
SF
1418sub _restore_options_after_restart
1419{
1420 my %options_map = get_list("PERLDB_OPT");
1421
1422 while ( my ( $opt, $val ) = each %options_map ) {
1423 $val =~ s/[\\\']/\\$1/g;
1424 parse_options("$opt'$val'");
1425 }
1426
1427 return;
1428}
1429
18580168
SF
1430sub _restore_globals_after_restart
1431{
1432 # restore original @INC
1433 @INC = get_list("PERLDB_INC");
1434 @ini_INC = @INC;
1435
1436 # return pre/postprompt actions and typeahead buffer
1437 $pretype = [ get_list("PERLDB_PRETYPE") ];
1438 $pre = [ get_list("PERLDB_PRE") ];
1439 $post = [ get_list("PERLDB_POST") ];
1440 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1441
1442 return;
1443}
1444
fb0fb5f4 1445
e18a02a6
SF
1446if ( exists $ENV{PERLDB_RESTART} ) {
1447
1448 # We're restarting, so we don't need the flag that says to restart anymore.
1449 delete $ENV{PERLDB_RESTART};
1450
1451 # $restart = 1;
fb0fb5f4 1452 _restore_shared_globals_after_restart();
e18a02a6
SF
1453
1454 _restore_breakpoints_and_actions();
1455
69893cff 1456 # restore options
ca50076b 1457 _restore_options_after_restart();
69893cff 1458
18580168 1459 _restore_globals_after_restart();
69893cff
RGS
1460} ## end if (exists $ENV{PERLDB_RESTART...
1461
1462=head2 SETTING UP THE TERMINAL
1463
1464Now, we'll decide how the debugger is going to interact with the user.
1465If there's no TTY, we set the debugger to run non-stop; there's not going
1466to be anyone there to enter commands.
1467
1468=cut
54d04a52 1469
ebd0282e 1470use vars qw($notty $console $tty $LINEINFO);
6b24a4b7
SF
1471use vars qw($lineinfo $doccmd);
1472
ebd0282e
SF
1473our ($runnonstop);
1474
e0047406
KF
1475# Local autoflush to avoid rt#116769,
1476# as calling IO::File methods causes an unresolvable loop
1477# that results in debugger failure.
1478sub _autoflush {
1479 my $o = select($_[0]);
1480 $|++;
1481 select($o);
1482}
1483
d338d6fe 1484if ($notty) {
69893cff 1485 $runnonstop = 1;
2dbd01ad 1486 share($runnonstop);
69893cff 1487}
d12a4851 1488
69893cff
RGS
1489=pod
1490
1491If there is a TTY, we have to determine who it belongs to before we can
1492proceed. If this is a slave editor or graphical debugger (denoted by
1493the first command-line switch being '-emacs'), we shift this off and
1494set C<$rl> to 0 (XXX ostensibly to do straight reads).
1495
1496=cut
1497
1498else {
e22ea7cc 1499
69893cff
RGS
1500 # Is Perl being run from a slave editor or graphical debugger?
1501 # If so, don't use readline, and set $slave_editor = 1.
2b0b9dd1
SF
1502 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1503 $rl = 0;
1504 shift(@main::ARGV);
1505 }
e22ea7cc
RF
1506
1507 #require Term::ReadLine;
d12a4851 1508
69893cff
RGS
1509=pod
1510
1511We then determine what the console should be on various systems:
1512
1513=over 4
1514
1515=item * Cygwin - We use C<stdin> instead of a separate device.
1516
1517=cut
1518
e22ea7cc
RF
1519 if ( $^O eq 'cygwin' ) {
1520
69893cff
RGS
1521 # /dev/tty is binary. use stdin for textmode
1522 undef $console;
1523 }
1524
f703fc96 1525=item * Unix - use F</dev/tty>.
69893cff
RGS
1526
1527=cut
1528
e22ea7cc 1529 elsif ( -e "/dev/tty" ) {
69893cff
RGS
1530 $console = "/dev/tty";
1531 }
1532
1533=item * Windows or MSDOS - use C<con>.
1534
1535=cut
1536
e22ea7cc 1537 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
69893cff
RGS
1538 $console = "con";
1539 }
1540
69893cff
RGS
1541=item * VMS - use C<sys$command>.
1542
1543=cut
1544
1545 else {
e22ea7cc 1546
69893cff
RGS
1547 # everything else is ...
1548 $console = "sys\$command";
d12a4851 1549 }
69893cff
RGS
1550
1551=pod
1552
1553=back
1554
1555Several other systems don't use a specific console. We C<undef $console>
1556for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
739a0b84 1557with a slave editor).
69893cff
RGS
1558
1559=cut
d12a4851 1560
e22ea7cc
RF
1561 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1562
69893cff 1563 # /dev/tty is binary. use stdin for textmode
e22ea7cc
RF
1564 $console = undef;
1565 }
1566
1567 if ( $^O eq 'NetWare' ) {
d12a4851 1568
69893cff
RGS
1569 # /dev/tty is binary. use stdin for textmode
1570 $console = undef;
1571 }
d12a4851 1572
69893cff
RGS
1573 # In OS/2, we need to use STDIN to get textmode too, even though
1574 # it pretty much looks like Unix otherwise.
e22ea7cc
RF
1575 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1576 { # In OS/2
1577 $console = undef;
1578 }
1579
69893cff
RGS
1580=pod
1581
1582If there is a TTY hanging around from a parent, we use that as the console.
1583
1584=cut
1585
e22ea7cc 1586 $console = $tty if defined $tty;
d12a4851 1587
b570d64b 1588=head2 SOCKET HANDLING
69893cff
RGS
1589
1590The debugger is capable of opening a socket and carrying out a debugging
1591session over the socket.
1592
1593If C<RemotePort> was defined in the options, the debugger assumes that it
1594should try to start a debugging session on that port. It builds the socket
1595and then tries to connect the input and output filehandles to it.
1596
1597=cut
1598
1599 # Handle socket stuff.
e22ea7cc
RF
1600
1601 if ( defined $remoteport ) {
1602
69893cff
RGS
1603 # If RemotePort was defined in the options, connect input and output
1604 # to the socket.
11653f7f 1605 $IN = $OUT = connect_remoteport();
69893cff
RGS
1606 } ## end if (defined $remoteport)
1607
1608=pod
1609
1610If no C<RemotePort> was defined, and we want to create a TTY on startup,
1611this is probably a situation where multiple debuggers are running (for example,
1612a backticked command that starts up another debugger). We create a new IN and
1613OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1614and if we can.
1615
1616=cut
1617
1618 # Non-socket.
1619 else {
e22ea7cc 1620
69893cff
RGS
1621 # Two debuggers running (probably a system or a backtick that invokes
1622 # the debugger itself under the running one). create a new IN and OUT
e22ea7cc 1623 # filehandle, and do the necessary mojo to create a new tty if we
69893cff 1624 # know how, and we can.
e22ea7cc
RF
1625 create_IN_OUT(4) if $CreateTTY & 4;
1626 if ($console) {
1627
69893cff 1628 # If we have a console, check to see if there are separate ins and
cd1191f1 1629 # outs to open. (They are assumed identical if not.)
69893cff 1630
e22ea7cc
RF
1631 my ( $i, $o ) = split /,/, $console;
1632 $o = $i unless defined $o;
69893cff 1633
69893cff 1634 # read/write on in, or just read, or read on STDIN.
e22ea7cc
RF
1635 open( IN, "+<$i" )
1636 || open( IN, "<$i" )
1637 || open( IN, "<&STDIN" );
1638
69893cff
RGS
1639 # read/write/create/clobber out, or write/create/clobber out,
1640 # or merge with STDERR, or merge with STDOUT.
e22ea7cc
RF
1641 open( OUT, "+>$o" )
1642 || open( OUT, ">$o" )
1643 || open( OUT, ">&STDERR" )
1644 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1645
1646 } ## end if ($console)
1647 elsif ( not defined $console ) {
1648
1649 # No console. Open STDIN.
1650 open( IN, "<&STDIN" );
1651
1652 # merge with STDERR, or with STDOUT.
1653 open( OUT, ">&STDERR" )
1654 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1655 $console = 'STDIN/OUT';
69893cff
RGS
1656 } ## end elsif (not defined $console)
1657
1658 # Keep copies of the filehandles so that when the pager runs, it
1659 # can close standard input without clobbering ours.
2b0b9dd1
SF
1660 if ($console or (not defined($console))) {
1661 $IN = \*IN;
1662 $OUT = \*OUT;
1663 }
e22ea7cc
RF
1664 } ## end elsif (from if(defined $remoteport))
1665
1666 # Unbuffer DB::OUT. We need to see responses right away.
e0047406 1667 _autoflush($OUT);
e22ea7cc
RF
1668
1669 # Line info goes to debugger output unless pointed elsewhere.
1670 # Pointing elsewhere makes it possible for slave editors to
1671 # keep track of file and position. We have both a filehandle
1672 # and a I/O description to keep track of.
1673 $LINEINFO = $OUT unless defined $LINEINFO;
1674 $lineinfo = $console unless defined $lineinfo;
2dbd01ad
SF
1675 # share($LINEINFO); # <- unable to share globs
1676 share($lineinfo); #
e22ea7cc 1677
69893cff
RGS
1678=pod
1679
1680To finish initialization, we show the debugger greeting,
1681and then call the C<afterinit()> subroutine if there is one.
1682
1683=cut
d12a4851 1684
e22ea7cc
RF
1685 # Show the debugger greeting.
1686 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1687 unless ($runnonstop) {
1688 local $\ = '';
1689 local $, = '';
1690 if ( $term_pid eq '-1' ) {
1691 print $OUT "\nDaughter DB session started...\n";
1692 }
1693 else {
1694 print $OUT "\nLoading DB routines from $header\n";
1695 print $OUT (
1696 "Editor support ",
1697 $slave_editor ? "enabled" : "available", ".\n"
1698 );
1699 print $OUT
1f874cb6 1700"\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
69893cff
RGS
1701 } ## end else [ if ($term_pid eq '-1')
1702 } ## end unless ($runnonstop)
1703} ## end else [ if ($notty)
1704
1705# XXX This looks like a bug to me.
1706# Why copy to @ARGS and then futz with @args?
d338d6fe 1707@ARGS = @ARGV;
6b24a4b7 1708# for (@args) {
69893cff
RGS
1709 # Make sure backslashes before single quotes are stripped out, and
1710 # keep args unless they are numeric (XXX why?)
e22ea7cc
RF
1711 # s/\'/\\\'/g; # removed while not justified understandably
1712 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
6b24a4b7 1713# }
d338d6fe 1714
e22ea7cc 1715# If there was an afterinit() sub defined, call it. It will get
69893cff 1716# executed in our scope, so it can fiddle with debugger globals.
e22ea7cc 1717if ( defined &afterinit ) { # May be defined in $rcfile
2b0b9dd1 1718 afterinit();
d338d6fe 1719}
e22ea7cc 1720
69893cff 1721# Inform us about "Stack dump during die enabled ..." in dieLevel().
6b24a4b7
SF
1722use vars qw($I_m_init);
1723
43aed9ee
IZ
1724$I_m_init = 1;
1725
d338d6fe
PP
1726############################################################ Subroutines
1727
69893cff
RGS
1728=head1 SUBROUTINES
1729
1730=head2 DB
1731
1732This gigantic subroutine is the heart of the debugger. Called before every
1733statement, its job is to determine if a breakpoint has been reached, and
1734stop if so; read commands from the user, parse them, and execute
b468dcb6 1735them, and then send execution off to the next statement.
69893cff
RGS
1736
1737Note that the order in which the commands are processed is very important;
1738some commands earlier in the loop will actually alter the C<$cmd> variable
be9a9b1d 1739to create other commands to be executed later. This is all highly I<optimized>
69893cff
RGS
1740but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1741see what's happening in any given command.
1742
1743=cut
1744
136ae23d
SF
1745# $cmd cannot be an our() variable unfortunately (possible perl bug?).
1746
6b24a4b7
SF
1747use vars qw(
1748 $action
6b24a4b7 1749 $cmd
6b24a4b7
SF
1750 $file
1751 $filename_ini
1752 $finished
1753 %had_breakpoints
6b24a4b7
SF
1754 $level
1755 $max
6b24a4b7 1756 $package
6b24a4b7
SF
1757 $try
1758);
1759
1ce985d2 1760our (
bdb3f37d 1761 %alias,
1ce985d2 1762 $doret,
0664c09a 1763 $end,
4d0e1f38 1764 $fall_off_end,
d1450c23 1765 $incr,
73c5e526 1766 $laststep,
14f38b27 1767 $rc,
ddf4cf26 1768 $sh,
1ce985d2
SF
1769 $stack_depth,
1770 @stack,
1771 @to_watch,
1772 @old_watch,
1773);
8ad70697 1774
6791e41b
SF
1775sub _DB__determine_if_we_should_break
1776{
1777 # if we have something here, see if we should break.
1778 # $stop is lexical and local to this block - $action on the other hand
1779 # is global.
1780 my $stop;
1781
1782 if ( $dbline{$line}
1783 && _is_breakpoint_enabled($filename, $line)
1784 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1785 {
1786
1787 # Stop if the stop criterion says to just stop.
1788 if ( $stop eq '1' ) {
1789 $signal |= 1;
1790 }
1791
1792 # It's a conditional stop; eval it in the user's context and
1793 # see if we should stop. If so, remove the one-time sigil.
1794 elsif ($stop) {
1795 $evalarg = "\$DB::signal |= 1 if do {$stop}";
e3d167f6 1796 DB::eval(@_);
6791e41b
SF
1797 # If the breakpoint is temporary, then delete its enabled status.
1798 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1799 _cancel_breakpoint_temp_enabled_status($filename, $line);
1800 }
1801 }
1802 } ## end if ($dbline{$line} && ...
1803}
1804
8481f647
SF
1805sub _DB__is_finished {
1806 if ($finished and $level <= 1) {
1807 end_report();
1808 return 1;
1809 }
1810 else {
1811 return;
1812 }
1813}
1814
32bbadc6
SF
1815sub _DB__read_next_cmd
1816{
1817 my ($tid) = @_;
1818
1819 # We have a terminal, or can get one ...
1820 if (!$term) {
1821 setterm();
1822 }
1823
7e3426ea 1824 # ... and it belongs to this PID or we get one for this PID ...
32bbadc6
SF
1825 if ($term_pid != $$) {
1826 resetterm(1);
1827 }
1828
1829 # ... and we got a line of command input ...
1830 $cmd = DB::readline(
1831 "$pidprompt $tid DB"
1832 . ( '<' x $level )
1833 . ( $#hist + 1 )
1834 . ( '>' x $level ) . " "
1835 );
1836
1837 return defined($cmd);
1838}
1839
7013f40c 1840sub _DB__trim_command_and_return_first_component {
af84fb69
SF
1841 my ($obj) = @_;
1842
7013f40c
SF
1843 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1844 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1845
3249b113 1846 my ($verb, $args) = $cmd =~ m{\A(\S*)\s*(.*)}s;
af84fb69 1847
3249b113
SF
1848 $obj->cmd_verb($verb);
1849 $obj->cmd_args($args);
af84fb69
SF
1850
1851 return;
7013f40c
SF
1852}
1853
2a802473 1854sub _DB__handle_f_command {
a30f63cd 1855 my ($obj) = @_;
2a802473 1856
a30f63cd 1857 if ($file = $obj->cmd_args) {
2a802473
SF
1858 # help for no arguments (old-style was return from sub).
1859 if ( !$file ) {
1860 print $OUT
1861 "The old f command is now the r command.\n"; # hint
1862 print $OUT "The new f command switches filenames.\n";
1863 next CMD;
1864 } ## end if (!$file)
1865
1866 # if not in magic file list, try a close match.
1867 if ( !defined $main::{ '_<' . $file } ) {
1868 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1869 {
1870 $try = substr( $try, 2 );
1871 print $OUT "Choosing $try matching '$file':\n";
1872 $file = $try;
1873 }
1874 } ## end if (($try) = grep(m#^_<.*$file#...
1875 } ## end if (!defined $main::{ ...
1876
1877 # If not successfully switched now, we failed.
1878 if ( !defined $main::{ '_<' . $file } ) {
1879 print $OUT "No file matching '$file' is loaded.\n";
1880 next CMD;
1881 }
1882
1883 # We switched, so switch the debugger internals around.
1884 elsif ( $file ne $filename ) {
1885 *dbline = $main::{ '_<' . $file };
1886 $max = $#dbline;
1887 $filename = $file;
1888 $start = 1;
1889 $cmd = "l";
1890 } ## end elsif ($file ne $filename)
1891
1892 # We didn't switch; say we didn't.
1893 else {
1894 print $OUT "Already in $file.\n";
1895 next CMD;
1896 }
1897 }
1898
1899 return;
1900}
1901
6115a173
SF
1902sub _DB__handle_dot_command {
1903 my ($obj) = @_;
1904
1905 # . command.
601c6a23 1906 if ($obj->_is_full('.')) {
6115a173
SF
1907 $incr = -1; # stay at current line
1908
1909 # Reset everything to the old location.
1910 $start = $line;
1911 $filename = $filename_ini;
1912 *dbline = $main::{ '_<' . $filename };
1913 $max = $#dbline;
1914
1915 # Now where are we?
1916 print_lineinfo($obj->position());
1917 next CMD;
1918 }
1919
1920 return;
1921}
1922
5c2b78e7
SF
1923sub _DB__handle_y_command {
1924 my ($obj) = @_;
1925
1926 if (my ($match_level, $match_vars)
9875a6d2 1927 = $obj->cmd_args =~ /\A(?:(\d*)\s*(.*))?\z/) {
5c2b78e7
SF
1928
1929 # See if we've got the necessary support.
84e7f475
SF
1930 if (!eval { require PadWalker; PadWalker->VERSION(0.08) }) {
1931 my $Err = $@;
b5679dc0 1932 _db_warn(
84e7f475
SF
1933 $Err =~ /locate/
1934 ? "PadWalker module not found - please install\n"
1935 : $Err
1936 );
1937 next CMD;
1938 }
5c2b78e7
SF
1939
1940 # Load up dumpvar if we don't have it. If we can, that is.
1941 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1942 defined &main::dumpvar
1943 or print $OUT "dumpvar.pl not available.\n"
1944 and next CMD;
1945
1946 # Got all the modules we need. Find them and print them.
1947 my @vars = split( ' ', $match_vars || '' );
1948
1949 # Find the pad.
1950 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
1951
1952 # Oops. Can't find it.
84e7f475
SF
1953 if (my $Err = $@) {
1954 $Err =~ s/ at .*//;
b5679dc0 1955 _db_warn($Err);
84e7f475
SF
1956 next CMD;
1957 }
5c2b78e7
SF
1958
1959 # Show the desired vars with dumplex().
1960 my $savout = select($OUT);
1961
1962 # Have dumplex dump the lexicals.
84e7f475
SF
1963 foreach my $key (sort keys %$h) {
1964 dumpvar::dumplex( $key, $h->{$key},
1965 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
1966 @vars );
1967 }
5c2b78e7
SF
1968 select($savout);
1969 next CMD;
1970 }
1971}
1972
35cd713a
SF
1973sub _DB__handle_c_command {
1974 my ($obj) = @_;
1975
a523ec7c 1976 my $i = $obj->cmd_args;
35cd713a 1977
a523ec7c 1978 if ($i =~ m#\A[\w:]*\z#) {
35cd713a
SF
1979
1980 # Hey, show's over. The debugged program finished
1981 # executing already.
1982 next CMD if _DB__is_finished();
1983
1984 # Capture the place to put a one-time break.
a523ec7c 1985 $subname = $i;
35cd713a
SF
1986
1987 # Probably not needed, since we finish an interactive
1988 # sub-session anyway...
1989 # local $filename = $filename;
1990 # local *dbline = *dbline; # XXX Would this work?!
1991 #
1992 # The above question wonders if localizing the alias
1993 # to the magic array works or not. Since it's commented
1994 # out, we'll just leave that to speculation for now.
1995
1996 # If the "subname" isn't all digits, we'll assume it
1997 # is a subroutine name, and try to find it.
1998 if ( $subname =~ /\D/ ) { # subroutine name
1999 # Qualify it to the current package unless it's
2000 # already qualified.
2001 $subname = $package . "::" . $subname
2002 unless $subname =~ /::/;
2003
2004 # find_sub will return "file:line_number" corresponding
2005 # to where the subroutine is defined; we call find_sub,
2006 # break up the return value, and assign it in one
2007 # operation.
a523ec7c 2008 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
35cd713a
SF
2009
2010 # Force the line number to be numeric.
a523ec7c 2011 $i = $i + 0;
35cd713a
SF
2012
2013 # If we got a line number, we found the sub.
a523ec7c 2014 if ($i) {
35cd713a
SF
2015
2016 # Switch all the debugger's internals around so
2017 # we're actually working with that file.
2018 $filename = $file;
2019 *dbline = $main::{ '_<' . $filename };
2020
2021 # Mark that there's a breakpoint in this file.
2022 $had_breakpoints{$filename} |= 1;
2023
2024 # Scan forward to the first executable line
2025 # after the 'sub whatever' line.
2026 $max = $#dbline;
a523ec7c 2027 my $_line_num = $i;
9c6fceaf
SF
2028 while ($dbline[$_line_num] == 0 && $_line_num< $max)
2029 {
2030 $_line_num++;
2031 }
a523ec7c 2032 $i = $_line_num;
35cd713a
SF
2033 } ## end if ($i)
2034
2035 # We didn't find a sub by that name.
2036 else {
2037 print $OUT "Subroutine $subname not found.\n";
2038 next CMD;
2039 }
2040 } ## end if ($subname =~ /\D/)
2041
2042 # At this point, either the subname was all digits (an
2043 # absolute line-break request) or we've scanned through
2044 # the code following the definition of the sub, looking
2045 # for an executable, which we may or may not have found.
2046 #
2047 # If $i (which we set $subname from) is non-zero, we
2048 # got a request to break at some line somewhere. On
2049 # one hand, if there wasn't any real subroutine name
2050 # involved, this will be a request to break in the current
2051 # file at the specified line, so we have to check to make
2052 # sure that the line specified really is breakable.
2053 #
2054 # On the other hand, if there was a subname supplied, the
2055 # preceding block has moved us to the proper file and
2056 # location within that file, and then scanned forward
2057 # looking for the next executable line. We have to make
2058 # sure that one was found.
2059 #
2060 # On the gripping hand, we can't do anything unless the
2061 # current value of $i points to a valid breakable line.
2062 # Check that.
a523ec7c 2063 if ($i) {
35cd713a
SF
2064
2065 # Breakable?
a523ec7c
SF
2066 if ( $dbline[$i] == 0 ) {
2067 print $OUT "Line $i not breakable.\n";
35cd713a
SF
2068 next CMD;
2069 }
2070
2071 # Yes. Set up the one-time-break sigil.
a523ec7c
SF
2072 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2073 _enable_breakpoint_temp_enabled_status($filename, $i);
35cd713a
SF
2074 } ## end if ($i)
2075
2076 # Turn off stack tracing from here up.
a523ec7c
SF
2077 for my $j (0 .. $stack_depth) {
2078 $stack[ $j ] &= ~1;
35cd713a
SF
2079 }
2080 last CMD;
2081 }
2082
2083 return;
2084}
2085
a4d311a3
SF
2086sub _DB__handle_forward_slash_command {
2087 my ($obj) = @_;
2088
2089 # The pattern as a string.
2090 use vars qw($inpat);
2091
2092 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2093
2094 # Remove the final slash.
2095 $inpat =~ s:([^\\])/$:$1:;
2096
2097 # If the pattern isn't null ...
2098 if ( $inpat ne "" ) {
2099
7e3426ea 2100 # Turn off warn and die processing for a bit.
a4d311a3
SF
2101 local $SIG{__DIE__};
2102 local $SIG{__WARN__};
2103
2104 # Create the pattern.
2105 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2106 if ( $@ ne "" ) {
2107
2108 # Oops. Bad pattern. No biscuit.
2109 # Print the eval error and go back for more
2110 # commands.
72c017e3 2111 print {$OUT} "$@";
a4d311a3
SF
2112 next CMD;
2113 }
2114 $obj->pat($inpat);
2115 } ## end if ($inpat ne "")
2116
2117 # Set up to stop on wrap-around.
2118 $end = $start;
2119
2120 # Don't move off the current line.
2121 $incr = -1;
2122
2123 my $pat = $obj->pat;
2124
2125 # Done in eval so nothing breaks if the pattern
2126 # does something weird.
2127 eval
2128 {
2129 no strict q/vars/;
2130 for (;;) {
2131 # Move ahead one line.
2132 ++$start;
2133
2134 # Wrap if we pass the last line.
72c017e3
SF
2135 if ($start > $max) {
2136 $start = 1;
2137 }
a4d311a3
SF
2138
2139 # Stop if we have gotten back to this line again,
2140 last if ($start == $end);
2141
2142 # A hit! (Note, though, that we are doing
2143 # case-insensitive matching. Maybe a qr//
2144 # expression would be better, so the user could
2145 # do case-sensitive matching if desired.
2146 if ($dbline[$start] =~ m/$pat/i) {
2147 if ($slave_editor) {
2148 # Handle proper escaping in the slave.
72c017e3 2149 print {$OUT} "\032\032$filename:$start:0\n";
a4d311a3
SF
2150 }
2151 else {
2152 # Just print the line normally.
72c017e3 2153 print {$OUT} "$start:\t",$dbline[$start],"\n";
a4d311a3
SF
2154 }
2155 # And quit since we found something.
2156 last;
2157 }
2158 }
2159 };
2160
2161 if ($@) {
2162 warn $@;
2163 }
2164
2165 # If we wrapped, there never was a match.
2166 if ( $start == $end ) {
2167 print {$OUT} "/$pat/: not found\n";
2168 }
2169 next CMD;
2170 }
2171
2172 return;
2173}
2174
11f0f050
SF
2175sub _DB__handle_question_mark_command {
2176 my ($obj) = @_;
2177
2178 # ? - backward pattern search.
2179 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2180
2181 # Get the pattern, remove trailing question mark.
2182 $inpat =~ s:([^\\])\?$:$1:;
2183
2184 # If we've got one ...
2185 if ( $inpat ne "" ) {
2186
2187 # Turn off die & warn handlers.
2188 local $SIG{__DIE__};
2189 local $SIG{__WARN__};
2190 eval '$inpat =~ m' . "\a$inpat\a";
2191
2192 if ( $@ ne "" ) {
2193
2194 # Ouch. Not good. Print the error.
2195 print $OUT $@;
2196 next CMD;
2197 }
2198 $obj->pat($inpat);
2199 } ## end if ($inpat ne "")
2200
2201 # Where we are now is where to stop after wraparound.
2202 $end = $start;
2203
2204 # Don't move away from this line.
2205 $incr = -1;
2206
2207 my $pat = $obj->pat;
2208 # Search inside the eval to prevent pattern badness
2209 # from killing us.
2210 eval {
2211 no strict q/vars/;
2212 for (;;) {
2213 # Back up a line.
2214 --$start;
2215
2216 # Wrap if we pass the first line.
2217
2218 $start = $max if ($start <= 0);
2219
2220 # Quit if we get back where we started,
2221 last if ($start == $end);
2222
2223 # Match?
2224 if ($dbline[$start] =~ m/$pat/i) {
2225 if ($slave_editor) {
2226 # Yep, follow slave editor requirements.
2227 print $OUT "\032\032$filename:$start:0\n";
2228 }
2229 else {
2230 # Yep, just print normally.
2231 print $OUT "$start:\t",$dbline[$start],"\n";
2232 }
2233
2234 # Found, so done.
2235 last;
2236 }
2237 }
2238 };
2239
2240 # Say we failed if the loop never found anything,
2241 if ( $start == $end ) {
2242 print {$OUT} "?$pat?: not found\n";
2243 }
2244 next CMD;
2245 }
2246
2247 return;
2248}
2249
5f166812
SF
2250sub _DB__handle_restart_and_rerun_commands {
2251 my ($obj) = @_;
2252
b9920278
SF
2253 my $cmd_cmd = $obj->cmd_verb;
2254 my $cmd_params = $obj->cmd_args;
5f166812
SF
2255 # R - restart execution.
2256 # rerun - controlled restart execution.
b9920278 2257 if ($cmd_cmd eq 'rerun' or $cmd_params eq '') {
5f166812
SF
2258 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
2259
2260 # Close all non-system fds for a clean restart. A more
2261 # correct method would be to close all fds that were not
2262 # open when the process started, but this seems to be
2263 # hard. See "debugger 'R'estart and open database
2264 # connections" on p5p.
2265
2266 my $max_fd = 1024; # default if POSIX can't be loaded
2267 if (eval { require POSIX }) {
2268 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
2269 }
2270
2271 if (defined $max_fd) {
2272 foreach ($^F+1 .. $max_fd-1) {
2273 next unless open FD_TO_CLOSE, "<&=$_";
2274 close(FD_TO_CLOSE);
2275 }
2276 }
2277
2278 # And run Perl again. We use exec() to keep the
2279 # PID stable (and that way $ini_pids is still valid).
2280 exec(@args) or print {$OUT} "exec failed: $!\n";
2281
2282 last CMD;
2283 }
2284
2285 return;
2286}
2287
33f361f5
SF
2288sub _DB__handle_run_command_in_pager_command {
2289 my ($obj) = @_;
2290
2291 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
2292 if ( $pager =~ /^\|/ ) {
2293
2294 # Default pager is into a pipe. Redirect I/O.
2295 open( SAVEOUT, ">&STDOUT" )
b5679dc0 2296 || _db_warn("Can't save STDOUT");
33f361f5 2297 open( STDOUT, ">&OUT" )
b5679dc0 2298 || _db_warn("Can't redirect STDOUT");
33f361f5
SF
2299 } ## end if ($pager =~ /^\|/)
2300 else {
2301
2302 # Not into a pipe. STDOUT is safe.
b5679dc0 2303 open( SAVEOUT, ">&OUT" ) || _db_warn("Can't save DB::OUT");
33f361f5
SF
2304 }
2305
2306 # Fix up environment to record we have less if so.
2307 fix_less();
2308
2309 unless ( $obj->piped(scalar ( open( OUT, $pager ) ) ) ) {
2310
2311 # Couldn't open pipe to pager.
b5679dc0 2312 _db_warn("Can't pipe output to '$pager'");
33f361f5
SF
2313 if ( $pager =~ /^\|/ ) {
2314
2315 # Redirect I/O back again.
2316 open( OUT, ">&STDOUT" ) # XXX: lost message
b5679dc0 2317 || _db_warn("Can't restore DB::OUT");
33f361f5 2318 open( STDOUT, ">&SAVEOUT" )
b5679dc0 2319 || _db_warn("Can't restore STDOUT");
33f361f5
SF
2320 close(SAVEOUT);
2321 } ## end if ($pager =~ /^\|/)
2322 else {
2323
2324 # Redirect I/O. STDOUT already safe.
2325 open( OUT, ">&STDOUT" ) # XXX: lost message
b5679dc0 2326 || _db_warn("Can't restore DB::OUT");
33f361f5
SF
2327 }
2328 next CMD;
2329 } ## end unless ($piped = open(OUT,...
2330
2331 # Set up broken-pipe handler if necessary.
2332 $SIG{PIPE} = \&DB::catch
2333 if $pager =~ /^\|/
2334 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
2335
e0047406 2336 _autoflush(\*OUT);
33f361f5
SF
2337 # Save current filehandle, and put it back.
2338 $obj->selected(scalar( select(OUT) ));
2339 # Don't put it back if pager was a pipe.
2340 if ($cmd !~ /\A\|\|/)
2341 {
2342 select($obj->selected());
2343 $obj->selected("");
2344 }
2345
2346 # Trim off the pipe symbols and run the command now.
2347 $cmd =~ s#\A\|+\s*##;
2348 redo PIPE;
2349 }
2350
2351 return;
2352}
2353
321095c5
SF
2354sub _DB__handle_m_command {
2355 my ($obj) = @_;
2356
2357 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2358 methods($1);
2359 next CMD;
2360 }
2361
2362 # m expr - set up DB::eval to do the work
2363 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2364 $onetimeDump = 'methods'; # method output gets used there
2365 }
2366
2367 return;
2368}
33f361f5 2369
8e4cceb9
SF
2370sub _DB__at_end_of_every_command {
2371 my ($obj) = @_;
2372
2373 # At the end of every command:
2374 if ($obj->piped) {
2375
2376 # Unhook the pipe mechanism now.
2377 if ( $pager =~ /^\|/ ) {
2378
2379 # No error from the child.
2380 $? = 0;
2381
2382 # we cannot warn here: the handle is missing --tchrist
2383 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
2384
2385 # most of the $? crud was coping with broken cshisms
2386 # $? is explicitly set to 0, so this never runs.
2387 if ($?) {
2388 print SAVEOUT "Pager '$pager' failed: ";
2389 if ( $? == -1 ) {
2390 print SAVEOUT "shell returned -1\n";
2391 }
2392 elsif ( $? >> 8 ) {
2393 print SAVEOUT ( $? & 127 )
2394 ? " (SIG#" . ( $? & 127 ) . ")"
2395 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
2396 }
2397 else {
2398 print SAVEOUT "status ", ( $? >> 8 ), "\n";
2399 }
2400 } ## end if ($?)
2401
2402 # Reopen filehandle for our output (if we can) and
2403 # restore STDOUT (if we can).
b5679dc0 2404 open( OUT, ">&STDOUT" ) || _db_warn("Can't restore DB::OUT");
8e4cceb9 2405 open( STDOUT, ">&SAVEOUT" )
b5679dc0 2406 || _db_warn("Can't restore STDOUT");
8e4cceb9
SF
2407
2408 # Turn off pipe exception handler if necessary.
2409 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
2410
2411 # Will stop ignoring SIGPIPE if done like nohup(1)
2412 # does SIGINT but Perl doesn't give us a choice.
2413 } ## end if ($pager =~ /^\|/)
2414 else {
2415
2416 # Non-piped "pager". Just restore STDOUT.
b5679dc0 2417 open( OUT, ">&SAVEOUT" ) || _db_warn("Can't restore DB::OUT");
8e4cceb9
SF
2418 }
2419
2420 # Close filehandle pager was using, restore the normal one
2421 # if necessary,
2422 close(SAVEOUT);
2423
2424 if ($obj->selected() ne "") {
2425 select($obj->selected);
2426 $obj->selected("");
2427 }
2428
2429 # No pipes now.
2430 $obj->piped("");
2431 } ## end if ($piped)
2432
2433 return;
2434}
2435
5f5eab52
SF
2436sub _DB__handle_watch_expressions
2437{
2438 my $self = shift;
2439
2440 if ( $DB::trace & 2 ) {
2441 for my $n (0 .. $#DB::to_watch) {
2442 $DB::evalarg = $DB::to_watch[$n];
2443 local $DB::onetimeDump; # Tell DB::eval() to not output results
2444
2445 # Fix context DB::eval() wants to return an array, but
2446 # we need a scalar here.
2447 my ($val) = join( "', '", DB::eval(@_) );
2448 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
2449
2450 # Did it change?
2451 if ( $val ne $DB::old_watch[$n] ) {
2452
2453 # Yep! Show the difference, and fake an interrupt.
2454 $DB::signal = 1;
2455 print {$DB::OUT} <<EOP;
2456Watchpoint $n:\t$DB::to_watch[$n] changed:
2457 old value:\t$DB::old_watch[$n]
2458 new value:\t$val
2459EOP
2460 $DB::old_watch[$n] = $val;
2461 } ## end if ($val ne $old_watch...
2462 } ## end for my $n (0 ..
2463 } ## end if ($trace & 2)
2464
2465 return;
2466}
2467
47e3b8cc
SF
2468# 't' is type.
2469# 'm' is method.
2470# 'v' is the value (i.e: method name or subroutine ref).
2471# 's' is subroutine.
2472my %cmd_lookup =
2473(
c9a9a6c0 2474 '-' => { t => 'm', v => '_handle_dash_command', },
d478d7a0 2475 '.' => { t => 's', v => \&_DB__handle_dot_command, },
8f144dfc
SF
2476 '=' => { t => 'm', v => '_handle_equal_sign_command', },
2477 'H' => { t => 'm', v => '_handle_H_command', },
c9a9a6c0
SF
2478 'S' => { t => 'm', v => '_handle_S_command', },
2479 'T' => { t => 'm', v => '_handle_T_command', },
8f144dfc 2480 'W' => { t => 'm', v => '_handle_W_command', },
c9a9a6c0 2481 'c' => { t => 's', v => \&_DB__handle_c_command, },
d478d7a0
SF
2482 'f' => { t => 's', v => \&_DB__handle_f_command, },
2483 'm' => { t => 's', v => \&_DB__handle_m_command, },
c9a9a6c0 2484 'n' => { t => 'm', v => '_handle_n_command', },
8f144dfc 2485 'p' => { t => 'm', v => '_handle_p_command', },
d478d7a0 2486 'q' => { t => 'm', v => '_handle_q_command', },
c9a9a6c0
SF
2487 'r' => { t => 'm', v => '_handle_r_command', },
2488 's' => { t => 'm', v => '_handle_s_command', },
8f144dfc
SF
2489 'save' => { t => 'm', v => '_handle_save_command', },
2490 'source' => { t => 'm', v => '_handle_source_command', },
d478d7a0 2491 't' => { t => 'm', v => '_handle_t_command', },
8f144dfc 2492 'w' => { t => 'm', v => '_handle_w_command', },
d478d7a0 2493 'x' => { t => 'm', v => '_handle_x_command', },
c9a9a6c0 2494 'y' => { t => 's', v => \&_DB__handle_y_command, },
d478d7a0
SF
2495 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, }
2496 ('X', 'V')),
8f144dfc
SF
2497 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, }
2498 qw(enable disable)),
2499 (map { $_ =>
2500 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, },
2501 } qw(R rerun)),
fbe9ebae 2502 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, }
ce1a6808 2503 qw(a A b B e E h i l L M o O v w W)),
47e3b8cc
SF
2504);
2505
2b0b9dd1
SF
2506sub DB {
2507
2508 # lock the debugger and get the thread id for the prompt
2509 lock($DBGR);
2510 my $tid;
2511 my $position;
2512 my ($prefix, $after, $infix);
2513 my $pat;
22fc883d 2514 my $explicit_stop;
33f361f5
SF
2515 my $piped;
2516 my $selected;
2b0b9dd1
SF
2517
2518 if ($ENV{PERL5DB_THREADED}) {
2519 $tid = eval { "[".threads->tid."]" };
2520 }
2521
610f01b9 2522 my $cmd_verb;
3249b113 2523 my $cmd_args;
35cd713a 2524
22fc883d
SF
2525 my $obj = DB::Obj->new(
2526 {
2527 position => \$position,
2528 prefix => \$prefix,
2529 after => \$after,
2530 explicit_stop => \$explicit_stop,
2531 infix => \$infix,
3249b113 2532 cmd_args => \$cmd_args,
610f01b9 2533 cmd_verb => \$cmd_verb,
a4d311a3 2534 pat => \$pat,
33f361f5
SF
2535 piped => \$piped,
2536 selected => \$selected,
22fc883d
SF
2537 },
2538 );
2539
2540 $obj->_DB_on_init__initialize_globals(@_);
2b0b9dd1 2541
69893cff
RGS
2542 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2543 # The code being debugged may have altered them.
b0b8faca 2544 DB::save();
69893cff
RGS
2545
2546 # Since DB::DB gets called after every line, we can use caller() to
2547 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 2548 # caller is returning all the extra information when called from the
69893cff 2549 # debugger.
e22ea7cc 2550 local ( $package, $filename, $line ) = caller;
6b24a4b7 2551 $filename_ini = $filename;
69893cff
RGS
2552
2553 # set up the context for DB::eval, so it can properly execute
2554 # code on behalf of the user. We add the package in so that the
2555 # code is eval'ed in the proper package (not in the debugger!).
6b24a4b7 2556 local $usercontext = _calc_usercontext($package);
69893cff
RGS
2557
2558 # Create an alias to the active file magical array to simplify
2559 # the code here.
e22ea7cc 2560 local (*dbline) = $main::{ '_<' . $filename };
aa057b67 2561
69893cff 2562 # Last line in the program.
55783941 2563 $max = $#dbline;
69893cff 2564
22fc883d 2565 _DB__determine_if_we_should_break(@_);
69893cff
RGS
2566
2567 # Preserve the current stop-or-not, and see if any of the W
2568 # (watch expressions) has changed.
36477c24 2569 my $was_signal = $signal;
69893cff
RGS
2570
2571 # If we have any watch expressions ...
5f5eab52 2572 _DB__handle_watch_expressions($obj);
69893cff
RGS
2573
2574=head2 C<watchfunction()>
2575
2576C<watchfunction()> is a function that can be defined by the user; it is a
b570d64b 2577function which will be run on each entry to C<DB::DB>; it gets the
69893cff
RGS
2578current package, filename, and line as its parameters.
2579
b570d64b 2580The watchfunction can do anything it likes; it is executing in the
69893cff
RGS
2581debugger's context, so it has access to all of the debugger's internal
2582data structures and functions.
2583
2584C<watchfunction()> can control the debugger's actions. Any of the following
2585will cause the debugger to return control to the user's program after
2586C<watchfunction()> executes:
2587
b570d64b 2588=over 4
69893cff 2589
be9a9b1d
AT
2590=item *
2591
2592Returning a false value from the C<watchfunction()> itself.
2593
2594=item *
2595
2596Altering C<$single> to a false value.
2597
2598=item *
69893cff 2599
be9a9b1d 2600Altering C<$signal> to a false value.
69893cff 2601
be9a9b1d 2602=item *
69893cff 2603
be9a9b1d 2604Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
2605check for C<watchfunction()>. This can be done with
2606
2607 $trace &= ~4;
2608
2609=back
2610
2611=cut
2612
e22ea7cc 2613 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
2614 # current package, filename, and line. The function executes in
2615 # the DB:: package.
e22ea7cc
RF
2616 if ( $trace & 4 ) { # User-installed watch
2617 return
2618 if watchfunction( $package, $filename, $line )
2619 and not $single
2620 and not $was_signal
2621 and not( $trace & ~4 );
69893cff
RGS
2622 } ## end if ($trace & 4)
2623
e22ea7cc 2624 # Pick up any alteration to $signal in the watchfunction, and
69893cff 2625 # turn off the signal now.
6027b9a3 2626 $was_signal = $signal;
69893cff
RGS
2627 $signal = 0;
2628
2629=head2 GETTING READY TO EXECUTE COMMANDS
2630
2631The debugger decides to take control if single-step mode is on, the
2632C<t> command was entered, or the user generated a signal. If the program
2633has fallen off the end, we set things up so that entering further commands
2634won't cause trouble, and we say that the program is over.
2635
2636=cut
2637
8dc67a69
SF
2638 # Make sure that we always print if asked for explicitly regardless
2639 # of $trace_to_depth .
22fc883d 2640 $explicit_stop = ($single || $was_signal);
8dc67a69 2641
69893cff
RGS
2642 # Check to see if we should grab control ($single true,
2643 # trace set appropriately, or we got a signal).
8dc67a69 2644 if ( $explicit_stop || ( $trace & 1 ) ) {
22fc883d 2645 $obj->_DB__grab_control(@_);
69893cff
RGS
2646 } ## end if ($single || ($trace...
2647
2648=pod
2649
2650If there's an action to be executed for the line we stopped at, execute it.
b570d64b 2651If there are any preprompt actions, execute those as well.
e219e2fb
RF
2652
2653=cut
2654
69893cff 2655 # If there's an action, do it now.
05da04df
SF
2656 if ($action) {
2657 $evalarg = $action;
e3d167f6 2658 DB::eval(@_);
05da04df 2659 }
e219e2fb 2660
69893cff
RGS
2661 # Are we nested another level (e.g., did we evaluate a function
2662 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
2663 if ( $single || $was_signal ) {
2664
69893cff 2665 # Yes, go down a level.
e22ea7cc 2666 local $level = $level + 1;
69893cff
RGS
2667
2668 # Do any pre-prompt actions.
e22ea7cc 2669 foreach $evalarg (@$pre) {
e3d167f6 2670 DB::eval(@_);
e22ea7cc 2671 }
69893cff
RGS
2672
2673 # Complain about too much recursion if we passed the limit.
05da04df
SF
2674 if ($single & 4) {
2675 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2676 }
69893cff
RGS
2677
2678 # The line we're currently on. Set $incr to -1 to stay here
2679 # until we get a command that tells us to advance.
e22ea7cc
RF
2680 $start = $line;
2681 $incr = -1; # for backward motion.
69893cff
RGS
2682
2683 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 2684 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
2685
2686=head2 WHERE ARE WE?
2687
2688XXX Relocate this section?
2689
2690The debugger normally shows the line corresponding to the current line of
2691execution. Sometimes, though, we want to see the next line, or to move elsewhere
2692in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2693
be9a9b1d
AT
2694C<$incr> controls by how many lines the I<current> line should move forward
2695after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2696line shouldn't change.
2697
be9a9b1d 2698C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2699move forwards or backwards from when doing an C<L> or C<-> command.
2700
2701C<$max> tells the debugger where the last line of the current file is. It's
2702used to terminate loops most often.
2703
2704=head2 THE COMMAND LOOP
2705
2706Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2707in two parts:
2708
2709=over 4
2710
be9a9b1d
AT
2711=item *
2712
2713The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2714reads a command and then executes it.
2715
be9a9b1d
AT
2716=item *
2717
2718The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2719is wholly contained inside the C<CMD> block and only executes a command.
2720Used to handle commands running inside a pager.
2721
2722=back
2723
2724So why have two labels to restart the loop? Because sometimes, it's easier to
2725have a command I<generate> another command and then re-execute the loop to do
2726the new command. This is faster, but perhaps a bit more convoluted.
2727
2728=cut
2729
2730 # The big command dispatch loop. It keeps running until the
2731 # user yields up control again.
2732 #
2733 # If we have a terminal for input, and we get something back
2734 # from readline(), keep on processing.
6b24a4b7 2735
e22ea7cc 2736 CMD:
32bbadc6 2737 while (_DB__read_next_cmd($tid))
69893cff 2738 {
e22ea7cc 2739
8380a245 2740 share($cmd);
69893cff
RGS
2741 # ... try to execute the input as debugger commands.
2742
2743 # Don't stop running.
2744 $single = 0;
2745
2746 # No signal is active.
2747 $signal = 0;
2748
2749 # Handle continued commands (ending with \):
3d7a2a93 2750 if ($cmd =~ s/\\\z/\n/) {
eeb7da96 2751 $cmd .= DB::readline(" cont: ");
e22ea7cc 2752 redo CMD;
3d7a2a93 2753 }
69893cff
RGS
2754
2755=head4 The null command
2756
be9a9b1d 2757A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2758command out of C<$laststep> (where it was recorded previously), and copy it
2759back into C<$cmd> to be executed below. If there wasn't any previous command,
2760we'll do nothing below (no command will match). If there was, we also save it
2761in the command history and fall through to allow the command parsing to pick
2762it up.
2763
2764=cut
2765
2766 # Empty input means repeat the last command.
eeb7da96
SF
2767 if ($cmd eq '') {
2768 $cmd = $laststep;
2769 }
e22ea7cc 2770 chomp($cmd); # get rid of the annoying extra newline
eeb7da96
SF
2771 if (length($cmd) >= 2) {
2772 push( @hist, $cmd );
2773 }
e22ea7cc 2774 push( @truehist, $cmd );
2dbd01ad
SF
2775 share(@hist);
2776 share(@truehist);
e22ea7cc
RF
2777
2778 # This is a restart point for commands that didn't arrive
2779 # via direct user input. It allows us to 'redo PIPE' to
2780 # re-execute command processing without reading a new command.
69893cff 2781 PIPE: {
af84fb69 2782 _DB__trim_command_and_return_first_component($obj);
69893cff
RGS
2783
2784=head3 COMMAND ALIASES
2785
2786The debugger can create aliases for commands (these are stored in the
2787C<%alias> hash). Before a command is executed, the command loop looks it up
2788in the alias hash and substitutes the contents of the alias for the command,
2789completely replacing it.
2790
2791=cut
2792
2793 # See if there's an alias for the command, and set it up if so.
610f01b9 2794 if ( $alias{$cmd_verb} ) {
e22ea7cc 2795
69893cff
RGS
2796 # Squelch signal handling; we want to keep control here
2797 # if something goes loco during the alias eval.
2798 local $SIG{__DIE__};
2799 local $SIG{__WARN__};
2800
2801 # This is a command, so we eval it in the DEBUGGER's
2802 # scope! Otherwise, we can't see the special debugger
2803 # variables, or get to the debugger's subs. (Well, we
2804 # _could_, but why make it even more complicated?)
610f01b9 2805 eval "\$cmd =~ $alias{$cmd_verb}";
69893cff
RGS
2806 if ($@) {
2807 local $\ = '';
610f01b9 2808 print $OUT "Couldn't evaluate '$cmd_verb' alias: $@";
69893cff
RGS
2809 next CMD;
2810 }
af84fb69 2811 _DB__trim_command_and_return_first_component($obj);
610f01b9 2812 } ## end if ($alias{$cmd_verb})
69893cff
RGS
2813
2814=head3 MAIN-LINE COMMANDS
2815
2816All of these commands work up to and after the program being debugged has
b570d64b 2817terminated.
69893cff
RGS
2818
2819=head4 C<q> - quit
2820
b570d64b 2821Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
69893cff
RGS
2822try to execute further, cleaning any restart-related stuff out of the
2823environment, and executing with the last value of C<$?>.
2824
2825=cut
2826
fbe9ebae
SF
2827 # All of these commands were remapped in perl 5.8.0;
2828 # we send them off to the secondary dispatcher (see below).
2829 $obj->_handle_special_char_cmd_wrapper_commands;
af84fb69 2830 _DB__trim_command_and_return_first_component($obj);
fbe9ebae 2831
610f01b9 2832 if (my $cmd_rec = $cmd_lookup{$cmd_verb}) {
47e3b8cc
SF
2833 my $type = $cmd_rec->{t};
2834 my $val = $cmd_rec->{v};
2835 if ($type eq 'm') {
2836 $obj->$val();
2837 }
2838 elsif ($type eq 's') {
2839 $val->($obj);
2840 }
2841 }
69893cff 2842
611272bb 2843=head4 C<t> - trace [n]
69893cff
RGS
2844
2845Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
611272bb 2846If level is specified, set C<$trace_to_depth>.
69893cff 2847
69893cff
RGS
2848=head4 C<S> - list subroutines matching/not matching a pattern
2849
2850Walks through C<%sub>, checking to see whether or not to print the name.
2851
69893cff
RGS
2852=head4 C<X> - list variables in current package
2853
b570d64b 2854Since the C<V> command actually processes this, just change this to the
69893cff
RGS
2855appropriate C<V> command and fall through.
2856
69893cff
RGS
2857=head4 C<V> - list variables
2858
b570d64b 2859Uses C<dumpvar.pl> to dump out the current values for selected variables.
69893cff 2860
69893cff
RGS
2861=head4 C<x> - evaluate and print an expression
2862
2863Hands the expression off to C<DB::eval>, setting it up to print the value
2864via C<dumpvar.pl> instead of just printing it directly.
2865
69893cff
RGS
2866=head4 C<m> - print methods
2867
2868Just uses C<DB::methods> to determine what methods are available.
2869
69893cff
RGS
2870=head4 C<f> - switch files
2871
73decac7 2872Switch to a different filename.
69893cff 2873
69893cff
RGS
2874=head4 C<.> - return to last-executed line.
2875
2876We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2877and then we look up the line in the magical C<%dbline> hash.
2878
69893cff
RGS
2879=head4 C<-> - back one window
2880
2881We change C<$start> to be one window back; if we go back past the first line,
2882we set it to be the first line. We ser C<$incr> to put us back at the
2883currently-executing line, and then put a C<l $start +> (list one window from
2884C<$start>) in C<$cmd> to be executed later.
2885
8481f647 2886=head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
69893cff
RGS
2887
2888In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2889problems, most notably that the default case of several commands destroying
2890the user's work in setting watchpoints, actions, etc. We wanted, however, to
2891retain the old commands for those who were used to using them or who preferred
2892them. At this point, we check for the new commands and call C<cmd_wrapper> to
2893deal with them instead of processing them in-line.
2894
69893cff
RGS
2895=head4 C<y> - List lexicals in higher scope
2896
826b9a2e 2897Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
69893cff
RGS
2898above the current one and then displays then using C<dumpvar.pl>.
2899
69893cff
RGS
2900=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2901
2902All of the commands below this point don't work after the program being
2903debugged has ended. All of them check to see if the program has ended; this
2904allows the commands to be relocated without worrying about a 'line of
2905demarcation' above which commands can be entered anytime, and below which
2906they can't.
2907
2908=head4 C<n> - single step, but don't trace down into subs
2909
2910Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2911when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
826b9a2e 2912so a null command knows what to re-execute.
69893cff 2913
69893cff
RGS
2914=head4 C<s> - single-step, entering subs
2915
826b9a2e 2916Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2917subs. Also saves C<s> as C<$lastcmd>.
2918
69893cff
RGS
2919=head4 C<c> - run continuously, setting an optional breakpoint
2920
2921Most of the code for this command is taken up with locating the optional
2922breakpoint, which is either a subroutine name or a line number. We set
2923the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2924in this and all call levels above this one.
2925
69893cff
RGS
2926=head4 C<r> - return from a subroutine
2927
2928For C<r> to work properly, the debugger has to stop execution again
2929immediately after the return is executed. This is done by forcing
2930single-stepping to be on in the call level above the current one. If
2931we are printing return values when a C<r> is executed, set C<$doret>
2932appropriately, and force us out of the command loop.
2933
69893cff
RGS
2934=head4 C<T> - stack trace
2935
2936Just calls C<DB::print_trace>.
2937
69893cff
RGS
2938=head4 C<w> - List window around current line.
2939
2940Just calls C<DB::cmd_w>.
2941
69893cff
RGS
2942=head4 C<W> - watch-expression processing.
2943
b570d64b 2944Just calls C<DB::cmd_W>.
69893cff 2945
69893cff
RGS
2946=head4 C</> - search forward for a string in the source
2947
ef18ae63 2948We take the argument and treat it as a pattern. If it turns out to be a
69893cff 2949bad one, we return the error we got from trying to C<eval> it and exit.
ef18ae63 2950If not, we create some code to do the search and C<eval> it so it can't
69893cff
RGS
2951mess us up.
2952
2953=cut
2954
a4d311a3 2955 _DB__handle_forward_slash_command($obj);
69893cff
RGS
2956
2957=head4 C<?> - search backward for a string in the source
2958
2959Same as for C</>, except the loop runs backwards.
2960
2961=cut
2962
11f0f050 2963 _DB__handle_question_mark_command($obj);
69893cff
RGS
2964
2965=head4 C<$rc> - Recall command
2966
2967Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
7e3426ea 2968that the terminal supports history). It finds the command required, puts it
69893cff
RGS
2969into C<$cmd>, and redoes the loop to execute it.
2970
2971=cut
2972
e22ea7cc 2973 # $rc - recall command.
14f38b27 2974 $obj->_handle_rc_recall_command;
69893cff
RGS
2975
2976=head4 C<$sh$sh> - C<system()> command
2977
f0bb1409 2978Calls the C<_db_system()> to handle the command. This keeps the C<STDIN> and
69893cff
RGS
2979C<STDOUT> from getting messed up.
2980
2981=cut
2982
466f24c7 2983 $obj->_handle_sh_command;
69893cff
RGS
2984
2985=head4 C<$rc I<pattern> $rc> - Search command history
2986
2987Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 2988If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
2989
2990=cut
2991
0d2c714c 2992 $obj->_handle_rc_search_history_command;
69893cff 2993
ef18ae63 2994=head4 C<$sh> - Invoke a shell
69893cff 2995
f0bb1409 2996Uses C<_db_system()> to invoke a shell.
69893cff
RGS
2997
2998=cut
2999
69893cff
RGS
3000=head4 C<$sh I<command>> - Force execution of a command in a shell
3001
3002Like the above, but the command is passed to the shell. Again, we use
f0bb1409 3003C<_db_system()> to avoid problems with C<STDIN> and C<STDOUT>.
69893cff 3004
69893cff
RGS
3005=head4 C<H> - display commands in history
3006
3007Prints the contents of C<@hist> (if any).
3008
69893cff
RGS
3009=head4 C<man, doc, perldoc> - look up documentation
3010
3011Just calls C<runman()> to print the appropriate document.
3012
3013=cut
3014
c7b0c61d 3015 $obj->_handle_doc_command;
69893cff
RGS
3016
3017=head4 C<p> - print
3018
3019Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3020the bottom of the loop.
3021
69893cff
RGS
3022=head4 C<=> - define command alias
3023
3024Manipulates C<%alias> to add or list command aliases.
3025
69893cff
RGS
3026=head4 C<source> - read commands from a file.
3027
3028Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3029pick it up.
3030
d0ecd4f3 3031=head4 C<enable> C<disable> - enable or disable breakpoints
e09195af 3032
d0ecd4f3 3033This enables or disables breakpoints.
e09195af 3034
69893cff
RGS
3035=head4 C<save> - send current history to a file
3036
3037Takes the complete history, (not the shrunken version you see with C<H>),
3038and saves it to the given filename, so it can be replayed using C<source>.
3039
3040Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3041
7fddc82f
RF
3042=head4 C<R> - restart
3043
ef18ae63 3044Restart the debugger session.
7fddc82f
RF
3045
3046=head4 C<rerun> - rerun the current session
3047
3048Return to any given position in the B<true>-history list
3049
69893cff
RGS
3050=head4 C<|, ||> - pipe output through the pager.
3051
be9a9b1d 3052For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
3053(the program's standard output). For C<||>, we only save C<OUT>. We open a
3054pipe to the pager (restoring the output filehandles if this fails). If this
b570d64b 3055is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
69893cff
RGS
3056set C<$signal>, sending us back into the debugger.
3057
3058We then trim off the pipe symbols and C<redo> the command loop at the
3059C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3060reading another.
3061
3062=cut
3063
3064 # || - run command in the pager, with output to DB::OUT.
33f361f5 3065 _DB__handle_run_command_in_pager_command($obj);
69893cff
RGS
3066
3067=head3 END OF COMMAND PARSING
3068
ff41e38d
SF
3069Anything left in C<$cmd> at this point is a Perl expression that we want to
3070evaluate. We'll always evaluate in the user's context, and fully qualify
69893cff
RGS
3071any variables we might want to address in the C<DB> package.
3072
3073=cut
3074
e22ea7cc 3075 } # PIPE:
69893cff 3076
e2b8b3e7
TC
3077 # trace an expression
3078 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3079
e22ea7cc 3080 # Make sure the flag that says "the debugger's running" is
69893cff 3081 # still on, to make sure we get control again.
e22ea7cc 3082 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3083
3084 # Run *our* eval that executes in the caller's context.
e3d167f6 3085 DB::eval(@_);
69893cff
RGS
3086
3087 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3088 if ($onetimeDump) {
3089 $onetimeDump = undef;
69893cff 3090 $onetimedumpDepth = undef;
e22ea7cc
RF
3091 }
3092 elsif ( $term_pid == $$ ) {
8380a245 3093 eval { # May run under miniperl, when not available...
c7e68384
IZ
3094 STDOUT->flush();
3095 STDERR->flush();
8380a245 3096 };
e22ea7cc 3097
69893cff 3098 # XXX If this is the master pid, print a newline.
8380a245 3099 print {$OUT} "\n";
e22ea7cc
RF
3100 }
3101 } ## end while (($term || &setterm...
69893cff
RGS
3102
3103=head3 POST-COMMAND PROCESSING
3104
3105After each command, we check to see if the command output was piped anywhere.
3106If so, we go through the necessary code to unhook the pipe and go back to
3107our standard filehandles for input and output.
3108
3109=cut
3110
e22ea7cc 3111 continue { # CMD:
8e4cceb9 3112 _DB__at_end_of_every_command($obj);
e22ea7cc 3113 } # CMD:
69893cff
RGS
3114
3115=head3 COMMAND LOOP TERMINATION
3116
3117When commands have finished executing, we come here. If the user closed the
3118input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3119evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3120C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3121The interpreter will then execute the next line and then return control to us
3122again.
3123
3124=cut
3125
3126 # No more commands? Quit.
1f874cb6 3127 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
69893cff
RGS
3128
3129 # Evaluate post-prompt commands.
e22ea7cc 3130 foreach $evalarg (@$post) {
e3d167f6 3131 DB::eval(@_);
e22ea7cc
RF
3132 }
3133 } # if ($single || $signal)
69893cff
RGS
3134
3135 # Put the user's globals back where you found them.
e22ea7cc 3136 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3137 ();
3138} ## end sub DB
3139
90fd4c80
KF
3140# Because DB::Obj is used above,
3141#
3142# my $obj = DB::Obj->new(
3143#
7e3426ea 3144# The following package declaration must come before that,
90fd4c80
KF
3145# or else runtime errors will occur with
3146#
3147# PERLDB_OPTS="autotrace nonstop"
3148#
3149# ( rt#116771 )
3150BEGIN {
3151
22fc883d
SF
3152package DB::Obj;
3153
3154sub new {
3155 my $class = shift;
3156
3157 my $self = bless {}, $class;
3158
3159 $self->_init(@_);
3160
3161 return $self;
3162}
3163
3164sub _init {
3165 my ($self, $args) = @_;
3166
3167 %{$self} = (%$self, %$args);
3168
3169 return;
3170}
3171
3172{
3173 no strict 'refs';
a4d311a3 3174 foreach my $slot_name (qw(
610f01b9 3175 after explicit_stop infix pat piped position prefix selected cmd_verb
3249b113 3176 cmd_args
a4d311a3 3177 )) {
22fc883d
SF
3178 my $slot = $slot_name;
3179 *{$slot} = sub {
3180 my $self = shift;
3181
3182 if (@_) {
3183 ${ $self->{$slot} } = shift;
3184 }
3185
3186 return ${ $self->{$slot} };
3187 };
8def6eff
SF
3188
3189 *{"append_to_$slot"} = sub {
3190 my $self = shift;
3191 my $s = shift;
3192
3193 return $self->$slot($self->$slot . $s);
3194 };
22fc883d
SF
3195 }
3196}
3197
3198sub _DB_on_init__initialize_globals
3199{
3200 my $self = shift;
3201
3202 # Check for whether we should be running continuously or not.
3203 # _After_ the perl program is compiled, $single is set to 1:
ebd0282e 3204 if ( $single and not $second_time++ ) {
22fc883d
SF
3205
3206 # Options say run non-stop. Run until we get an interrupt.
ebd0282e 3207 if ($runnonstop) { # Disable until signal
22fc883d
SF
3208 # If there's any call stack in place, turn off single
3209 # stepping into subs throughout the stack.
8ad70697
SF
3210 for my $i (0 .. $stack_depth) {
3211 $stack[ $i ] &= ~1;
22fc883d
SF
3212 }
3213
3214 # And we are now no longer in single-step mode.
ebd0282e 3215 $single = 0;
22fc883d
SF
3216
3217 # If we simply returned at this point, we wouldn't get
3218 # the trace info. Fall on through.
3219 # return;
3220 } ## end if ($runnonstop)
3221
8ad70697 3222 elsif ($ImmediateStop) {
22fc883d
SF
3223
3224 # We are supposed to stop here; XXX probably a break.
8ad70697 3225 $ImmediateStop = 0; # We've processed it; turn it off
ebd0282e 3226 $signal = 1; # Simulate an interrupt to force
22fc883d
SF
3227 # us into the command loop
3228 }
3229 } ## end if ($single and not $second_time...
3230
3231 # If we're in single-step mode, or an interrupt (real or fake)
3232 # has occurred, turn off non-stop mode.
ebd0282e 3233 $runnonstop = 0 if $single or $signal;
22fc883d
SF
3234
3235 return;
3236}
3237
ad46ac70
SF
3238sub _my_print_lineinfo
3239{
3240 my ($self, $i, $incr_pos) = @_;
3241
18b5b545 3242 if ($frame) {
ad46ac70 3243 # Print it indented if tracing is on.
8ad70697 3244 DB::print_lineinfo( ' ' x $stack_depth,
ad46ac70
SF
3245 "$i:\t$DB::dbline[$i]" . $self->after );
3246 }
3247 else {
3248 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3249 }
3250}
3251
44a07e3e 3252sub _curr_line {
18b5b545 3253 return $DB::dbline[$line];
44a07e3e
SF
3254}
3255
601c6a23
SF
3256sub _is_full {
3257 my ($self, $letter) = @_;
3258
3259 return ($DB::cmd eq $letter);
3260}
3261
22fc883d
SF
3262sub _DB__grab_control
3263{
3264 my $self = shift;
3265
3266 # Yes, grab control.
7793e5c2 3267 if ($slave_editor) {
22fc883d
SF
3268
3269 # Tell the editor to update its position.
18b5b545 3270 $self->position("\032\032${DB::filename}:$line:0\n");
22fc883d
SF
3271 DB::print_lineinfo($self->position());
3272 }
3273
3274=pod
3275
3276Special check: if we're in package C<DB::fake>, we've gone through the
3277C<END> block at least once. We set up everything so that we can continue
3278to enter commands and have a valid context to be in.
3279
3280=cut
3281
3282 elsif ( $DB::package eq 'DB::fake' ) {
3283
3284 # Fallen off the end already.
3285 if (!$DB::term) {
3286 DB::setterm();
3287 }
3288
3289 DB::print_help(<<EOP);
3290Debugged program terminated. Use B<q> to quit or B<R> to restart,
3291use B<o> I<inhibit_exit> to avoid stopping after program termination,
3292B<h q>, B<h R> or B<h o> to get additional info.
3293EOP
3294
3295 # Set the DB::eval context appropriately.
3296 $DB::package = 'main';
3297 $DB::usercontext = DB::_calc_usercontext($DB::package);
3298 } ## end elsif ($package eq 'DB::fake')
3299
3300=pod
3301
3302If the program hasn't finished executing, we scan forward to the
3303next executable line, print that out, build the prompt from the file and line
3304number information, and print that.
3305
3306=cut
3307
3308 else {
3309
3310
3311 # Still somewhere in the midst of execution. Set up the
3312 # debugger prompt.
3313 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3314 # Perl 5 ones (sorry, we don't print Klingon
3315 #module names)
3316
3317 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
8def6eff 3318 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
44a07e3e 3319 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3320
3321 # Break up the prompt if it's really long.
3322 if ( length($self->prefix()) > 30 ) {
18b5b545 3323 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
22fc883d
SF
3324 $self->prefix("");
3325 $self->infix(":\t");
3326 }
3327 else {
3328 $self->infix("):\t");
3329 $self->position(
18b5b545 3330 $self->prefix . $line. $self->infix
44a07e3e 3331 . $self->_curr_line . $self->after
22fc883d
SF
3332 );
3333 }
3334
3335 # Print current line info, indenting if necessary.
18b5b545 3336 $self->_my_print_lineinfo($line, $self->position);
22fc883d 3337
44a07e3e
SF
3338 my $i;
3339 my $line_i = sub { return $DB::dbline[$i]; };
3340
22fc883d
SF
3341 # Scan forward, stopping at either the end or the next
3342 # unbreakable line.
18b5b545 3343 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
22fc883d
SF
3344 { #{ vi
3345
3346 # Drop out on null statements, block closers, and comments.
44a07e3e 3347 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
22fc883d
SF
3348
3349 # Drop out if the user interrupted us.
ebd0282e 3350 last if $signal;
22fc883d
SF
3351
3352 # Append a newline if the line doesn't have one. Can happen
3353 # in eval'ed text, for instance.
44a07e3e 3354 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3355
3356 # Next executable line.
44a07e3e 3357 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
22fc883d 3358 . $self->after;
8def6eff 3359 $self->append_to_position($incr_pos);
ad46ac70 3360 $self->_my_print_lineinfo($i, $incr_pos);
22fc883d
SF
3361 } ## end for ($i = $line + 1 ; $i...
3362 } ## end else [ if ($slave_editor)
3363
3364 return;
3365}
3366
174f9c5e 3367sub _handle_t_command {
9875a6d2
SF
3368 my $self = shift;
3369
3370 my $levels = $self->cmd_args();
3371
3372 if ((!length($levels)) or ($levels !~ /\D/)) {
931ac036 3373 $trace ^= 1;
174f9c5e 3374 local $\ = '';
8ad70697
SF
3375 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3376 print {$OUT} "Trace = "
931ac036 3377 . ( ( $trace & 1 )
174f9c5e
SF
3378 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3379 : "off" ) . "\n";
3380 next CMD;
3381 }
3382
3383 return;
3384}
3385
9d0b71b3
SF
3386
3387sub _handle_S_command {
3249b113
SF
3388 my $self = shift;
3389
9d0b71b3 3390 if (my ($print_all_subs, $should_reverse, $Spatt)
3249b113 3391 = $self->cmd_args =~ /\A((!)?(.+))?\z/) {
9d0b71b3
SF
3392 # $Spatt is the pattern (if any) to use.
3393 # Reverse scan?
3394 my $Srev = defined $should_reverse;
3395 # No args - print all subs.
3396 my $Snocheck = !defined $print_all_subs;
3397
3398 # Need to make these sane here.
3399 local $\ = '';
3400 local $, = '';
3401
3402 # Search through the debugger's magical hash of subs.
3403 # If $nocheck is true, just print the sub name.
3404 # Otherwise, check it against the pattern. We then use
3405 # the XOR trick to reverse the condition as required.
3406 foreach $subname ( sort( keys %sub ) ) {
3407 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3408 print $OUT $subname, "\n";
3409 }
3410 }
3411 next CMD;
3412 }
3413
3414 return;
3415}
3416
1ce985d2 3417sub _handle_V_command_and_X_command {
601c6a23 3418 my $self = shift;
1ce985d2
SF
3419
3420 $DB::cmd =~ s/^X\b/V $DB::package/;
3421
3422 # Bare V commands get the currently-being-debugged package
3423 # added.
601c6a23 3424 if ($self->_is_full('V')) {
1ce985d2
SF
3425 $DB::cmd = "V $DB::package";
3426 }
3427
3428 # V - show variables in package.
3429 if (my ($new_packname, $new_vars_str) =
3430 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3431
3432 # Save the currently selected filehandle and
3433 # force output to debugger's filehandle (dumpvar
3434 # just does "print" for output).
3435 my $savout = select($OUT);
3436
3437 # Grab package name and variables to dump.
3438 $packname = $new_packname;
3439 my @vars = split( ' ', $new_vars_str );
3440
3441 # If main::dumpvar isn't here, get it.
3442 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3443 if ( defined &main::dumpvar ) {
3444
3445 # We got it. Turn off subroutine entry/exit messages
3446 # for the moment, along with return values.
3447 local $frame = 0;
3448 local $doret = -2;
3449
3450 # must detect sigpipe failures - not catching
3451 # then will cause the debugger to die.
3452 eval {
b0b8faca 3453 main::dumpvar(
1ce985d2
SF
3454 $packname,
3455 defined $option{dumpDepth}
3456 ? $option{dumpDepth}
3457 : -1, # assume -1 unless specified
3458 @vars
3459 );
3460 };
3461
3462 # The die doesn't need to include the $@, because
3463 # it will automatically get propagated for us.
3464 if ($@) {
3465 die unless $@ =~ /dumpvar print failed/;
3466 }
3467 } ## end if (defined &main::dumpvar)
3468 else {
3469
3470 # Couldn't load dumpvar.
3471 print $OUT "dumpvar.pl not available.\n";
3472 }
3473
3474 # Restore the output filehandle, and go round again.
3475 select($savout);
3476 next CMD;
3477 }
3478
3479 return;
3480}
3481
d1450c23 3482sub _handle_dash_command {
601c6a23 3483 my $self = shift;
d1450c23 3484
601c6a23 3485 if ($self->_is_full('-')) {
d1450c23
SF
3486
3487 # back up by a window; go to 1 if back too far.
3488 $start -= $incr + $window + 1;
3489 $start = 1 if $start <= 0;
3490 $incr = $window - 1;
3491
3492 # Generate and execute a "l +" command (handled below).
3493 $DB::cmd = 'l ' . ($start) . '+';
fbe9ebae 3494 redo CMD;
d1450c23
SF
3495 }
3496 return;
3497}
3498
cb9d1513
SF
3499sub _n_or_s_commands_generic {
3500 my ($self, $new_val) = @_;
73c5e526 3501 # n - next
cb9d1513 3502 next CMD if DB::_DB__is_finished();
73c5e526 3503
cb9d1513
SF
3504 # Single step, but don't enter subs.
3505 $single = $new_val;
3506
3507 # Save for empty command (repeat last).
3508 $laststep = $DB::cmd;
3509 last CMD;
3510}
73c5e526 3511
cb9d1513
SF
3512sub _n_or_s {
3513 my ($self, $letter, $new_val) = @_;
3514
601c6a23 3515 if ($self->_is_full($letter)) {
cb9d1513 3516 $self->_n_or_s_commands_generic($new_val);
73c5e526 3517 }
a30f63cd 3518 else {
50a8a759
SF
3519 $self->_n_or_s_and_arg_commands_generic($letter, $new_val);
3520 }
73c5e526
SF
3521
3522 return;
3523}
3524
cb9d1513
SF
3525sub _handle_n_command {
3526 my $self = shift;
3527
3528 return $self->_n_or_s('n', 2);
3529}
3530
3531sub _handle_s_command {
3532 my $self = shift;
3533
3534 return $self->_n_or_s('s', 1);
3535}
3536
573b5003
SF
3537sub _handle_r_command {
3538 my $self = shift;
f89bf53e 3539
573b5003 3540 # r - return from the current subroutine.
601c6a23 3541 if ($self->_is_full('r')) {
573b5003
SF
3542
3543 # Can't do anything if the program's over.
3544 next CMD if DB::_DB__is_finished();
3545
3546 # Turn on stack trace.
3547 $stack[$stack_depth] |= 1;
3548
3549 # Print return value unless the stack is empty.
3550 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3551 last CMD;
3552 }
3553
3554 return;
3555}
3556
d4038e14 3557sub _handle_T_command {
601c6a23
SF
3558 my $self = shift;
3559
3560 if ($self->_is_full('T')) {
d4038e14
SF
3561 DB::print_trace( $OUT, 1 ); # skip DB
3562 next CMD;
3563 }
3564
3565 return;
3566}
3567
b6e88520 3568sub _handle_w_command {
9875a6d2
SF
3569 my $self = shift;
3570
3571 DB::cmd_w( 'w', $self->cmd_args() );
3572 next CMD;
b6e88520
SF
3573
3574 return;
3575}
3576
25953301 3577sub _handle_W_command {
a523ec7c
SF
3578 my $self = shift;
3579
3580 if (my $arg = $self->cmd_args) {
25953301
SF
3581 DB::cmd_W( 'W', $arg );
3582 next CMD;
3583 }
3584
3585 return;
3586}
3587
14f38b27
SF
3588sub _handle_rc_recall_command {
3589 my $self = shift;
3590
3591 # $rc - recall command.
3592 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3593
3594 # No arguments, take one thing off history.
3595 pop(@hist) if length($DB::cmd) > 1;
3596
3597 # Relative (- found)?
3598 # Y - index back from most recent (by 1 if bare minus)
3599 # N - go to that particular command slot or the last
3600 # thing if nothing following.
14f38b27 3601
9c6fceaf
SF
3602 $self->cmd_verb(
3603 scalar($minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist ))
3604 );
14f38b27
SF
3605
3606 # Pick out the command desired.
610f01b9 3607 $DB::cmd = $hist[$self->cmd_verb];
14f38b27
SF
3608
3609 # Print the command to be executed and restart the loop
3610 # with that command in the buffer.
3611 print {$OUT} $DB::cmd, "\n";
3612 redo CMD;
3613 }
3614
3615 return;
3616}
3617
0d2c714c
SF
3618sub _handle_rc_search_history_command {
3619 my $self = shift;
3620
3621 # $rc pattern $rc - find a command in the history.
3622 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) {
3623
3624 # Create the pattern to use.
3625 my $pat = "^$arg";
3626 $self->pat($pat);
3627
3628 # Toss off last entry if length is >1 (and it always is).
3629 pop(@hist) if length($DB::cmd) > 1;
3630
9c6fceaf 3631 my $i;
0d2c714c
SF
3632
3633 # Look backward through the history.
3634 SEARCH_HIST:
3635 for ( $i = $#hist ; $i ; --$i ) {
3636 # Stop if we find it.
3637 last SEARCH_HIST if $hist[$i] =~ /$pat/;
3638 }
3639
9c6fceaf 3640 if ( !$i ) {
0d2c714c
SF
3641
3642 # Never found it.
3643 print $OUT "No such command!\n\n";
3644 next CMD;
3645 }
3646
3647 # Found it. Put it in the buffer, print it, and process it.
9c6fceaf 3648 $DB::cmd = $hist[$i];
0d2c714c
SF
3649 print $OUT $DB::cmd, "\n";
3650 redo CMD;
3651 }
b6aeebb8
SF
3652
3653 return;
0d2c714c
SF
3654}
3655
0664c09a
SF
3656sub _handle_H_command {
3657 my $self = shift;
3658
3249b113 3659 if ($self->cmd_args =~ m#\A\*#) {
0664c09a
SF
3660 @hist = @truehist = ();
3661 print $OUT "History cleansed\n";
3662 next CMD;
3663 }
3664
3249b113 3665 if (my ($num) = $self->cmd_args =~ /\A(?:-(\d+))?/) {
0664c09a
SF
3666
3667 # Anything other than negative numbers is ignored by
3668 # the (incorrect) pattern, so this test does nothing.
3669 $end = $num ? ( $#hist - $num ) : 0;
3670
3671 # Set to the minimum if less than zero.
3672 $hist = 0 if $hist < 0;
3673
3674 # Start at the end of the array.
3675 # Stay in while we're still above the ending value.
3676 # Tick back by one each time around the loop.
3677 my $i;
3678
3679 for ( $i = $#hist ; $i > $end ; $i-- ) {
3680
3681 # Print the command unless it has no arguments.
3682 print $OUT "$i: ", $hist[$i], "\n"
3683 unless $hist[$i] =~ /^.?$/;
3684 }
3685
0664c09a
SF
3686 next CMD;
3687 }
3688
3689 return;
3690}
3691
c7b0c61d
SF
3692sub _handle_doc_command {
3693 my $self = shift;
3694
3695 # man, perldoc, doc - show manual pages.
3696 if (my ($man_page)
3697 = $DB::cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
b019bbd2 3698 DB::runman($man_page);
c7b0c61d
SF
3699 next CMD;
3700 }
3701
3702 return;
3703}
3704
b6aeebb8
SF
3705sub _handle_p_command {
3706 my $self = shift;
3707
3708 my $print_cmd = 'print {$DB::OUT} ';
3709 # p - print (no args): print $_.
601c6a23 3710 if ($self->_is_full('p')) {
b6aeebb8
SF
3711 $DB::cmd = $print_cmd . '$_';
3712 }
a30f63cd
SF
3713 else {
3714 # p - print the given expression.
3715 $DB::cmd =~ s/\Ap\b/$print_cmd /;
3716 }
b6aeebb8
SF
3717
3718 return;
3719}
3720
bdb3f37d
SF
3721sub _handle_equal_sign_command {
3722 my $self = shift;
3723
3724 if ($DB::cmd =~ s/\A=\s*//) {
3725 my @keys;
3726 if ( length $DB::cmd == 0 ) {
3727
3728 # No args, get current aliases.
3729 @keys = sort keys %alias;
3730 }
3731 elsif ( my ( $k, $v ) = ( $DB::cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3732
3733 # Creating a new alias. $k is alias name, $v is
3734 # alias value.
3735
3736 # can't use $_ or kill //g state
3737 for my $x ( $k, $v ) {
3738
3739 # Escape "alarm" characters.
3740 $x =~ s/\a/\\a/g;
3741 }
3742
3743 # Substitute key for value, using alarm chars
3744 # as separators (which is why we escaped them in
3745 # the command).
3746 $alias{$k} = "s\a$k\a$v\a";
3747
3748 # Turn off standard warn and die behavior.
3749