This file is indexed.

/usr/bin/ptksh is in perl-tk 1:804.031-1build1.

This file is owned by root:root, with mode 0o755.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
#!/usr/bin/perl -w

eval 'exec /usr/bin/perl -w -S $0 ${1+"$@"}'
    if 0; # not running under some shell
#
# PTKSH 2.0
#
# A graphical user interface for testing Perl/Tk commands and scripts.
#
# VERSION HISTORY:
# ...truncated earlier stuff...
# 4/23/98  V1.7    Achim Bohnet  -- some fixes to "o" command
# 6/08/98  V2.01  M. Beller -- merge in GUI code for "wish"-like interface
#
# 2.01d1 6/6/98 First development version
#
# 2.01d2 6/7/98
#  - apply A.B. patch for pod and -option
#  - fix "use of uninitialized variable" in END{ } block (for -c option)
#  - support h and ? only for help
#  - misc. pod fixes (PITFALLS)
#  - use default fonts and default colors  ## NOT YET--still working on it
#  - get rid of Data::Dumper for history
#
# 2.01d3 6/8/98
#  - Remove "use Data::Dumper" line
#  - Put in hack for unix vs. win32 window manager focus problem
#  - Achim's pod and histfile patch
#
# 2.01d4 6/18/98
#  - Slaven's patch to make <Home> work properly
#  - Add help message to banner (per Steve Lydie)
#  - Fix horizontal scrolling (turn off wrapping in console window)
#  - Clarify <Up> in docs and help means "up arrow"
#  - Use HOMEDRIVE/HOMEPATH on Win32
#
# For more history look at the various Changes files in the Perl/Tk
# distribution.

=head1 NAME

ptksh - Perl/Tk script to provide a graphical user interface for testing Perl/Tk
commands and scripts.

=head1 SYNOPSIS

  % ptksh  ?scriptfile?
  ... version information ...
  ptksh> $b=$mw->Button(-text=>'Hi',-command=>sub{print 'Hi'})
  ptksh> $b->pack
  ptksh> o $b
  ... list of options ...
  ptksh> help
  ... help information ...
  ptksh> exit
  %


=head1 DESCRIPTION

ptksh is a perl/Tk shell to enter perl commands
interactively.  When one starts ptksh a L<MainWindow|Tk::MainWindow>
is automatically created, along with a ptksh command window.
One can access the main window by typing commands using the
variable $mw at the 'ptksh> ' prompt of the command window.

ptksh supports command line editing and history.  Just type "<Up>" at
the command prompt to see a history list.  The last 50 commands entered
are saved, then reloaded into history list the next time you start ptksh.

ptksh supports some convenient commands for inspecting Tk widgets.  See below.

To exit ptksh use: C<exit>.

ptksh is B<*not*> a full symbolic debugger.
To debug perl/Tk programs at a low level use the more powerful
L<perl debugger|perldebug>.  (Just enter ``O tk'' on debuggers
command line to start the Tk eventloop.)

=head1 FEATURES

=head2 History

Press <Up> (the Up Arrow) in the perlwish window to obtain a gui-based history list.
Press <Enter> on any history line to enter it into the perlwish window.
Then hit return.  So, for example, repeat last command is <Up><Enter><Enter>.
You can quit the history window with <Escape>.  NOTE: history is only saved
if exit is "graceful" (i.e. by the "exit" command from the console or by
quitting all main windows--NOT by interrupt).

=head2 Debugging Support

ptksh provides some convenience function to make browsing
in perl/Tk widget easier:

=over 4

=item B<?>, or B<h>

displays a short help summary.

=item B<d>, or B<x> ?I<args>, ...?

Dumps recursively arguments to stdout. (see L<Data::Dumper>).
You must have <Data::Dumper> installed to support this feature.

B<x> was introduced for perl debugger compatibility.

=item B<p> ?I<arg>, ...?

appends "|\n" to each of it's arguments and prints it.
If value is B<undef>, '(undef)' is printed to stdout.

=item B<o> I<$widget> ?I<-option> ...?

prints the option(s) of I<$widget> one on each line.
If no options are given all options of the widget are
listed.  See L<Tk::options> for more details on the
format and contents of the returned list.

=item B<o> I<$widget> B</>I<regexp>B</>

Lists options of I<$widget> matching the
L<regular expression|perlre> I<regexp>.

=item B<u> ?I<class>?

If no argument is given it lists the modules loaded
by the commands you executed or since the last time you
called C<u>.

If argument is the empty string lists all modules that are
loaded by ptksh.

If argument is a string, ``text'' it tries to do a ``use Tk::Text;''.

=back

=head2 Packages

Ptksh compiles into package Tk::ptksh.  Your code is eval'ed into package
main.  The coolness of this is that your eval code should not interfere with
ptksh itself.

=head2 Multiline Commands

ptksh will accept multiline commands.  Simply put a "\" character immediately
before the newline, and ptksh will continue your command onto the next line.

=head2 Source File Support

If you have a perl/Tk script that you want to do debugging on, try running the
command

  ptksh> do 'myscript';

   -- or  (at shell command prompt) --

  % ptksh myscript

Then use the perl/Tk commands to try out different operations on your script.

=head1 ENVIRONMENT

Looks for your .ptksh_history in the directory specified by
the $HOME environment variable ($HOMEPATH on Win32 systems).

=head1 FILES

=over 4

=item F<.ptksh_init>

If found in current directory it is read in an evaluated
after the mainwindow I<$mw> is created. F<.ptksh_init>
can contain any valid perl code.

=item F<~/.ptksh_history>

Contains the last 50 lines entered in ptksh session(s).

=back

=head1 PITFALLS

It is best not to use "my" in the commands you type into ptksh.
For example "my $v" will make $v local just to the command or commands
entered until <Return> is pressed.
For a related reason, there are no file-scopy "my" variables in the
ptksh code itself (else the user might trounce on them by accident).

=head1 BUGS

B<Tk::MainLoop> function interactively entered or sourced in a
init or script file will block ptksh.

=head1 SEE ALSO

L<Tk|Tk>
L<perldebug|perldebug>

=head1 VERSION

VERSION 2.03

=head1 AUTHORS

Mike Beller <beller@penvision.com>,
Achim Bohnet <ach@mpe.mpg.de>

Copyright (c) 1996 - 1998 Achim Bohnet and Mike Beller. All rights reserved.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.

=cut

package Tk::ptksh;
require 5.004;
use strict;
use Tk;

##### Constants

use vars qw($NAME $VERSION $FONT @FONT $WIN32 $HOME $HISTFILE $HISTSAVE $PROMPT $INITFILE);

$NAME = 'ptksh';
$VERSION = '2.03';
$WIN32 = 1 if $^O =~ /Win32/;
$HOME = $WIN32 ? ($ENV{HOMEDRIVE} . $ENV{HOMEPATH}) || 'C:\\' : $ENV{HOME} . "/";
@FONT = ($WIN32 ? (-font => 'systemfixed') : () );
#@FONT = ($WIN32 ? (-font => ['courier', 9, 'normal']) : () );
$HISTFILE = "${HOME}.${NAME}_history";
$HISTSAVE = 50;
$INITFILE = ".${NAME}_init";
$PROMPT = "$NAME> ";

sub Win32Fix { my $p = shift; $p =~ s'\\'/'g; $p =~ s'/$''; return $p }

use vars qw($mw $st $t @hist $hist $list $isStartOfCommand);

# NOTE: mainwindow creation order seems to impact who gets focus, and
# order is different on Win32 & *nix!!  So hack is to create the windows
# in an order dependent on the OS!

$mw = Tk::MainWindow->new unless $WIN32;  # &&& hack to work around focus problem

##### set up user's main window
package main;
$main::mw = Tk::MainWindow->new;
$main::mw->title('$mw');
$main::mw->geometry("+1+1");
package Tk::ptksh;

##### Set up ptksh windows
$mw = Tk::MainWindow->new if $WIN32;  # &&& hack to work around focus problem
$mw->title($NAME);
$st = $mw->Scrolled('Text', -scrollbars => 'osoe',
				-wrap => 'none',
				-width => 80, -height => 25, @FONT);
$t = $st->Subwidget('scrolled');
$st->pack(-fill => 'both', -expand => 'true');
# $mw_mapped assures that Center is only called exactly twice: first time
# will determine geometry of window, second time centering will work.
# I observed a couple of further <Map> events, which are now ignored
# and thus window creation seems to be faster now.
my $mw_mapped;
$mw->bind('<Map>', sub {return if $mw_mapped && $mw_mapped>=2; Center($mw); $mw_mapped++;} );

# Event bindings
$t->bindtags([$t, ref($t), $t->toplevel, 'all']); # take first crack at events
$t->bind('<Return>', \&EvalInput);
$t->bind('<BackSpace>', \&BackSpace);
$t->bind('<Escape>', \&HistKill);
$t->bind('<Up>', \&History);
$t->bind('<Control-a>', \&BeginLine);
$t->bind('<Home>', \&BeginLine);
$t->bind('<Any-KeyPress>', [\&Key, Tk::Ev('K'), Tk::Ev('A')]);

my $default_font = $t->cget(-font);
my %default_font = $t->fontActual($default_font);
my $normal_font;
if (!$t->fontMetrics($default_font, '-fixed')) {
    $normal_font = $t->fontCreate(%default_font, -family => "courier");
    $t->configure(-font => $normal_font);
} else {
    $normal_font = $default_font;
}
my %normal_font = $t->fontActual($normal_font);
my $bold_font = $t->fontCreate(%normal_font, -weight => "bold");

# Set up different colors for the various window outputs
#$t->tagConfigure('prompt', -underline => 'true');
$t->tagConfigure('prompt', -foreground => 'blue', -font => $bold_font);
$t->tagConfigure('result', -foreground => 'purple');
$t->tagConfigure('error', -foreground => 'red');
$t->tagConfigure('output', -foreground => 'blue');

# The tag 'limit' is the beginning of the input command line
$t->markSet('limit', 'insert');
$t->markGravity('limit', 'left');

# redirect stdout
#tie (*STDOUT, 'Tk::Text', $t);
tie (*STDOUT, 'Tk::ptksh');
#tie (*STDERR, 'Tk::ptksh');

# Print banner
print "$NAME V$VERSION";
print " perl V$] Tk V$Tk::VERSION  MainWindow -> \$mw\n";
print "\n\t\@INC:\n";
foreach (@INC) { print "\t  $_\n" };
print "Type 'h<Return>' at the prompt for help\n";

##### Read .ptkshinit
if ( -r $INITFILE)
  {
    print "Reading $INITFILE ...\n";
    package main;
    do $Tk::ptksh::INITFILE;
    package Tk::ptksh;
  }

###### Source the file if given as argument 0
if (defined($ARGV[0]) && -r $ARGV[0])
  {
    print "Reading $ARGV[0] ...\n";
    package main;
    do $ARGV[0];
    package Tk::ptksh;
  }

##### Read history
@hist = ();
if ( -r $HISTFILE and open(HIST, $HISTFILE) ) {
	print "Reading history ...\n";
	my $c = "";
	while (<HIST>) {
		chomp;
		$c .= $_;
		if ($_ !~ /\\$/) { #end of command if no trailing "\"
			push @hist, $c;
			$c = "";
		} else {
			chop $c;	# kill trailing "\"
			$c .= "\n";
		}
	}
    close HIST;
}

##### Initial prompt
Prompt($PROMPT);
$Tk::ptksh::mw->focus;
$t->focus;
#$mw->after(1000, sub {print STDERR "now\n"; $mw->focus; $t->focus;});

##### Now enter main loop
#$mw->afterIdle(sub {Center($mw);});
MainLoop();

####### Callbacks/etc.

# EvalInput -- Eval the input area (between 'limit' and 'insert')
#              in package main;
use vars qw($command $result); # use globals instead of "my" to avoid conflict w/ 'eval'
sub EvalInput {
	# If return is hit when not inside the command entry range, reprompt
	if ($t->compare('insert', '<=', 'limit')) {
		$t->markSet('insert', 'end');
		Prompt($PROMPT);
		Tk->break;
	}

	# Support multi-line commands
	if ($t->get('insert-1c', 'insert') eq "\\") {
		$t->insert('insert', "\n");
		$t->insert('insert', "> ", 'prompt'); # must use this pattern for continue
		$t->see('insert');
		Tk->break;
	}

	# Get the command and strip out continuations
	$command = $t->get('limit','end');
	$t->markSet('insert','end');
	$command =~ s/\\\n>\s/\n/mg;

	# Eval it
	if ( $command !~ /^\s*$/) {
		chomp $command;
		push(@hist, $command)
			unless @hist && ($command eq $hist[$#hist]); #could elim more redundancy

		$t->insert('insert', "\n");

		$isStartOfCommand = 1;

		$command = PtkshCommand($command);

		exit if ($command eq 'exit');

		package main;
		no strict;
		$Tk::ptksh::result = eval "local \$^W=0; $Tk::ptksh::command;";
		use strict;
		package Tk::ptksh;

		if ($t->compare('insert', '!=', 'insert linestart')) {
			$t->insert('insert', "\n");
		}
		if ($@) {
			$t->insert('insert', '## ' . $@, 'error');
		} else {
			$result = "" if !defined($result);
			$t->insert('insert', '# ' . $result, 'result');
		}
	}

	Prompt($PROMPT);

	Tk->break;
}

sub Prompt {
	my $pr = shift;

	if ($t->compare('insert', '!=', 'insert linestart')) {
		$t->insert('insert', "\n");
	}

	$t->insert('insert', $pr, 'prompt');
	$t->see('insert');
	$t->markSet('limit', 'insert');

}

sub BackSpace {
	if ($t->tagNextrange('sel', '1.0', 'end')) {
		$t->delete('sel.first', 'sel.last');
		} elsif ($t->compare('insert', '>', 'limit')) {
			$t->delete('insert-1c');
			$t->see('insert');
		}
		Tk->break;
}

sub BeginLine {
       $t->SetCursor('limit');
       $t->break;
}

sub Key {
	my ($self, $k, $a) = @_;
	#print "key event: ", $k, "\n";
	if ($t->compare('insert', '<', 'limit')) {
		$t->markSet('insert', 'end');
	}
	#$t->break; #for testing bindtags
}

sub History {
	Tk->break if defined($hist);

	$hist = $mw->Toplevel;
	$hist->title('History');
	$list = $hist->ScrlListbox(-scrollbars => 'oe',
              -width => 30, -height => 10, @FONT)->pack(qw(-fill both -expand 1));
	Center($hist);
	$list->insert('end', @hist);
	$list->see('end');
	$list->activate('end');
	$hist->bind('<Double-1>', \&HistPick);
	$hist->bind('<Return>', \&HistPick);
	$hist->bind('<Escape>', \&HistKill);
	my $hist_mapped; # see above for $mw_mapped
	$hist->bind('<Map>', sub {return if $hist_mapped && $hist_mapped>=2; Center($hist); $hist_mapped++;} );
	$hist->bind('<Destroy>', \&HistDestroy);
	$hist->focus;
	$list->focus;
	$hist->grab;
	#$mw->afterIdle(sub {Center($hist);});
	Tk->break;
}

sub HistPick {
	my $item = $list->get('active');
	return if (!$item);
	$t->markSet('insert', 'end');
	$t->insert('insert',$item);
	$t->see('insert');
	$mw->focus;
	$t->focus;
	HistKill();
}

sub HistKill {
	if ($hist) {
		$hist->grabRelease;
		$hist->destroy;
	}
}

# Called from destroy event mapping
sub HistDestroy {
	if (defined($hist) && (shift == $hist)) {
		$hist = undef;
		$mw->focus;
		$t->focus;
	}
}

sub LastCommand {
	if ($t->compare('insert', '==', 'limit')) {
		$t->insert('insert', $hist[$#hist]);
		$t->break;
	}
}

# Center a toplevel on screen or above parent
sub Center {
	my $w = shift;
	my ($x, $y);

	if ($w->parent) {
		#print STDERR $w->screenwidth, " ", $w->width, "\n";
		$x = $w->parent->x + ($w->parent->width - $w->width)/2;
		$y = $w->parent->y + ($w->parent->height - $w->height)/2;
	} else {
		#print STDERR $w->screenwidth, " ", $w->width, "\n";
		$x = ($w->screenwidth - $w->width)/2;
		$y = ($w->screenheight - $w->height)/2;
	}
	$x = int($x);
	$y = int($y);
	my $g = "+$x+$y";
	#print STDERR "Setting geometry to $g\n";
	$w->geometry($g);
}

# To deal with "TIE".
# We have to make sure the prints don't go into the command entry range.

sub TIEHANDLE {	# just to capture the tied calls
	my $self = [];
	return bless $self;

}

sub PRINT {
	my ($bogus) = shift;

	$t->markSet('insert', 'end');

	if ($isStartOfCommand) {  # Then no prints have happened in this command yet so...
		if ($t->compare('insert', '!=', 'insert linestart')) {
			$t->insert('insert', "\n");
		}
		# set flag so we know at least one print happened in this eval
		$isStartOfCommand = 0;
	}

	while (@_) {
		$t->insert('end', shift, 'output');
	}

	$t->see('insert');

	$t->markSet('limit', 'insert'); # don't interpret print as an input command
}

sub PRINTF
{
 my $w = shift;
 $w->PRINT(sprintf(shift,@_));
}

###
### Utility function
###

sub _o
  {
    my $w = shift;
    my $what = shift;

    $what =~ s/^\s+//;
    $what =~ s/\s+$//;
    my (@opt) = split " ", $what;

    print 'o(', join('|', @opt), ")\n";
    require Tk::Pretty;

    # check for regexp
    if ($opt[0] =~ s|^/(.*)/$|$1|)
      {
	print "options matching /$opt[0]/:\n";
        foreach ($w->configure())
          {
            print Tk::Pretty::Pretty($_),"\n" if $_->[0] =~ /\Q$opt[0]\E/;
          }
        return;
    }

    # list of options (allow as bar words)
    foreach (@opt)
      {
	s/^['"]//;
	s/,$//;
	s/['"]$//;
	s/^([^-])/-$1/;
      }
    if (length $what)
      {
       foreach (@opt)
          {
            print Tk::Pretty::Pretty($w->configure($_)),"\n";
          }
      }
    else
      {
        foreach ($w->configure()) { print Tk::Pretty::Pretty($_),"\n" }
      }
  }

sub _p {
    foreach (@_) { print $_, "|\n"; }
}

use vars qw($u_init %u_last $u_cnt);
$u_init = 0;
%u_last = ();
sub _u {
    my $module = shift;
    if (defined($module) and $module ne '') {
	$module = "Tk/".ucfirst($module).".pm" unless $module =~ /^Tk/;
	print " --- Loading $module ---\n";
	require "$module";
	print $@ if $@;
    } else {
        %u_last = () if defined $module;
	$u_cnt = 0;
	foreach (sort keys %INC) {
	    next if exists $u_last{$_};
            $u_cnt++;
            $u_last{$_} = 1;
	    #next if m,^/, and m,\.ix$,; # Ignore autoloader files
	    #next if m,\.ix$,; # Ignore autoloader files

	    if (length($_) < 20 ) {
		printf "%-20s -> %s\n", $_, $INC{$_};
	    } else {
		print "$_ -> $INC{$_}\n";
	    }
        }
	print STDERR "No modules loaded since last 'u' command (or startup)\n"
		unless $u_cnt;
    }
}

sub _d
  {
    require Data::Dumper;
    local $Data::Dumper::Deparse;
    $Data::Dumper::Deparse = 1;
    print Data::Dumper::Dumper(@_);
  }

sub _h
  {
    print <<'EOT';

  ? or h          print this message
  d or x arg,...  calls Data::Dumper::Dumper
  p arg,...       print args, each on a line and "|\n"
  o $w /regexp/   print options of widget matching regexp
  o $w [opt ...]  print (all) options of widget
  u xxx           xxx = string : load Tk::Xxx
			       = ''     : list all modules loaded
			       = undef  : list modules loaded since last u call
				              (or after ptksh startup)

  Press <Up> (the "up arrow" key) for command history
  Press <Escape> to leave command history window
  Type "exit" to quit (saves history)
  Type \<Return> for continuation of command to following line

EOT
}


# Substitute our special commands into the command line
sub PtkshCommand {
	$_ = shift;

	foreach ($_) {
		last if s/^\?\s*$/Tk::ptksh::_h /;
		last if s/^h\s*$/Tk::ptksh::_h /;
		last if s/^u(\s+|$)/Tk::ptksh::_u /;
		last if s/^[dx]\s+/Tk::ptksh::_d /;
		last if s/^u\s+(\S+)/Tk::ptksh::_u('$1')/;
		last if s/^p\s+(.*)$/Tk::ptksh::_p $1;/;
		last if s/^o\s+(\S+)\s*?$/Tk::ptksh::_o $1;/;
		last if s/^o\s+(\S+)\s*,?\s+(.*)?$/Tk::ptksh::_o $1, '$2';/;
    }
    %u_last = %INC unless $u_init++;

    # print STDERR "Command is: $_\n";

    $_;
}

###
### Save History -- use Data::Dumper to preserve multiline commands
###

END {
	if ($HISTFILE) {  # because this is probably perl -c if $HISTFILE is not set
		$#hist-- if $hist[-1] =~ /^(q$|x$|\s*exit\b)/; # chop off the exit command

	    @hist = @hist[($#hist-$HISTSAVE)..($#hist)] if $#hist > $HISTSAVE;

		if( open HIST, ">$HISTFILE" ) {
			while ($_ = shift(@hist)) {
				s/\n/\\\n/mg;
				print HIST "$_\n";
			}
			close HIST;
		} else {
			print STDERR "Error: Unable to open history file '$HISTFILE'\n";
		}
	}
}

1;  # just in case we decide to be "use"'able in the future.