1=head1 NAME
2
3Git - Perl interface to the Git version control system
4
5=cut
6
7
8package Git;
9
10use 5.008;
11use strict;
12use warnings $ENV{GIT_PERL_FATAL_WARNINGS} ? qw(FATAL all) : ();
13
14BEGIN {
15
16our ($VERSION, @ISA, @EXPORT, @EXPORT_OK);
17
18# Totally unstable API.
19$VERSION = '0.01';
20
21
22=head1 SYNOPSIS
23
24  use Git;
25
26  my $version = Git::command_oneline('version');
27
28  git_cmd_try { Git::command_noisy('update-server-info') }
29              '%s failed w/ code %d';
30
31  my $repo = Git->repository (Directory => '/srv/git/cogito.git');
32
33
34  my @revs = $repo->command('rev-list', '--since=last monday', '--all');
35
36  my ($fh, $c) = $repo->command_output_pipe('rev-list', '--since=last monday', '--all');
37  my $lastrev = <$fh>; chomp $lastrev;
38  $repo->command_close_pipe($fh, $c);
39
40  my $lastrev = $repo->command_oneline( [ 'rev-list', '--all' ],
41                                        STDERR => 0 );
42
43  my $sha1 = $repo->hash_and_insert_object('file.txt');
44  my $tempfile = tempfile();
45  my $size = $repo->cat_blob($sha1, $tempfile);
46
47=cut
48
49
50require Exporter;
51
52@ISA = qw(Exporter);
53
54@EXPORT = qw(git_cmd_try);
55
56# Methods which can be called as standalone functions as well:
57@EXPORT_OK = qw(command command_oneline command_noisy
58                command_output_pipe command_input_pipe command_close_pipe
59                command_bidi_pipe command_close_bidi_pipe
60                version exec_path html_path hash_object git_cmd_try
61                remote_refs prompt
62                get_tz_offset get_record
63                credential credential_read credential_write
64                temp_acquire temp_is_locked temp_release temp_reset temp_path
65                unquote_path);
66
67
68=head1 DESCRIPTION
69
70This module provides Perl scripts easy way to interface the Git version control
71system. The modules have an easy and well-tested way to call arbitrary Git
72commands; in the future, the interface will also provide specialized methods
73for doing easily operations which are not totally trivial to do over
74the generic command interface.
75
76While some commands can be executed outside of any context (e.g. 'version'
77or 'init'), most operations require a repository context, which in practice
78means getting an instance of the Git object using the repository() constructor.
79(In the future, we will also get a new_repository() constructor.) All commands
80called as methods of the object are then executed in the context of the
81repository.
82
83Part of the "repository state" is also information about path to the attached
84working copy (unless you work with a bare repository). You can also navigate
85inside of the working copy using the C<wc_chdir()> method. (Note that
86the repository object is self-contained and will not change working directory
87of your process.)
88
89TODO: In the future, we might also do
90
91	my $remoterepo = $repo->remote_repository (Name => 'cogito', Branch => 'master');
92	$remoterepo ||= Git->remote_repository ('http://git.or.cz/cogito.git/');
93	my @refs = $remoterepo->refs();
94
95Currently, the module merely wraps calls to external Git tools. In the future,
96it will provide a much faster way to interact with Git by linking directly
97to libgit. This should be completely opaque to the user, though (performance
98increase notwithstanding).
99
100=cut
101
102
103sub carp { require Carp; goto &Carp::carp }
104sub croak { require Carp; goto &Carp::croak }
105use Git::LoadCPAN::Error qw(:try);
106}
107
108
109=head1 CONSTRUCTORS
110
111=over 4
112
113=item repository ( OPTIONS )
114
115=item repository ( DIRECTORY )
116
117=item repository ()
118
119Construct a new repository object.
120C<OPTIONS> are passed in a hash like fashion, using key and value pairs.
121Possible options are:
122
123B<Repository> - Path to the Git repository.
124
125B<WorkingCopy> - Path to the associated working copy; not strictly required
126as many commands will happily crunch on a bare repository.
127
128B<WorkingSubdir> - Subdirectory in the working copy to work inside.
129Just left undefined if you do not want to limit the scope of operations.
130
131B<Directory> - Path to the Git working directory in its usual setup.
132The C<.git> directory is searched in the directory and all the parent
133directories; if found, C<WorkingCopy> is set to the directory containing
134it and C<Repository> to the C<.git> directory itself. If no C<.git>
135directory was found, the C<Directory> is assumed to be a bare repository,
136C<Repository> is set to point at it and C<WorkingCopy> is left undefined.
137If the C<$GIT_DIR> environment variable is set, things behave as expected
138as well.
139
140You should not use both C<Directory> and either of C<Repository> and
141C<WorkingCopy> - the results of that are undefined.
142
143Alternatively, a directory path may be passed as a single scalar argument
144to the constructor; it is equivalent to setting only the C<Directory> option
145field.
146
147Calling the constructor with no options whatsoever is equivalent to
148calling it with C<< Directory => '.' >>. In general, if you are building
149a standard porcelain command, simply doing C<< Git->repository() >> should
150do the right thing and setup the object to reflect exactly where the user
151is right now.
152
153=cut
154
155sub repository {
156	my $class = shift;
157	my @args = @_;
158	my %opts = ();
159	my $self;
160
161	if (defined $args[0]) {
162		if ($#args % 2 != 1) {
163			# Not a hash.
164			$#args == 0 or throw Error::Simple("bad usage");
165			%opts = ( Directory => $args[0] );
166		} else {
167			%opts = @args;
168		}
169	}
170
171	if (not defined $opts{Repository} and not defined $opts{WorkingCopy}
172		and not defined $opts{Directory}) {
173		$opts{Directory} = '.';
174	}
175
176	if (defined $opts{Directory}) {
177		-d $opts{Directory} or throw Error::Simple("Directory not found: $opts{Directory} $!");
178
179		my $search = Git->repository(WorkingCopy => $opts{Directory});
180		my $dir;
181		try {
182			$dir = $search->command_oneline(['rev-parse', '--git-dir'],
183			                                STDERR => 0);
184		} catch Git::Error::Command with {
185			$dir = undef;
186		};
187
188		require Cwd;
189		if ($dir) {
190			require File::Spec;
191			File::Spec->file_name_is_absolute($dir) or $dir = $opts{Directory} . '/' . $dir;
192			$opts{Repository} = Cwd::abs_path($dir);
193
194			# If --git-dir went ok, this shouldn't die either.
195			my $prefix = $search->command_oneline('rev-parse', '--show-prefix');
196			$dir = Cwd::abs_path($opts{Directory}) . '/';
197			if ($prefix) {
198				if (substr($dir, -length($prefix)) ne $prefix) {
199					throw Error::Simple("rev-parse confused me - $dir does not have trailing $prefix");
200				}
201				substr($dir, -length($prefix)) = '';
202			}
203			$opts{WorkingCopy} = $dir;
204			$opts{WorkingSubdir} = $prefix;
205
206		} else {
207			# A bare repository? Let's see...
208			$dir = $opts{Directory};
209
210			unless (-d "$dir/refs" and -d "$dir/objects" and -e "$dir/HEAD") {
211				# Mimic git-rev-parse --git-dir error message:
212				throw Error::Simple("fatal: Not a git repository: $dir");
213			}
214			my $search = Git->repository(Repository => $dir);
215			try {
216				$search->command('symbolic-ref', 'HEAD');
217			} catch Git::Error::Command with {
218				# Mimic git-rev-parse --git-dir error message:
219				throw Error::Simple("fatal: Not a git repository: $dir");
220			}
221
222			$opts{Repository} = Cwd::abs_path($dir);
223		}
224
225		delete $opts{Directory};
226	}
227
228	$self = { opts => \%opts };
229	bless $self, $class;
230}
231
232=back
233
234=head1 METHODS
235
236=over 4
237
238=item command ( COMMAND [, ARGUMENTS... ] )
239
240=item command ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
241
242Execute the given Git C<COMMAND> (specify it without the 'git-'
243prefix), optionally with the specified extra C<ARGUMENTS>.
244
245The second more elaborate form can be used if you want to further adjust
246the command execution. Currently, only one option is supported:
247
248B<STDERR> - How to deal with the command's error output. By default (C<undef>)
249it is delivered to the caller's C<STDERR>. A false value (0 or '') will cause
250it to be thrown away. If you want to process it, you can get it in a filehandle
251you specify, but you must be extremely careful; if the error output is not
252very short and you want to read it in the same process as where you called
253C<command()>, you are set up for a nice deadlock!
254
255The method can be called without any instance or on a specified Git repository
256(in that case the command will be run in the repository context).
257
258In scalar context, it returns all the command output in a single string
259(verbatim).
260
261In array context, it returns an array containing lines printed to the
262command's stdout (without trailing newlines).
263
264In both cases, the command's stdin and stderr are the same as the caller's.
265
266=cut
267
268sub command {
269	my ($fh, $ctx) = command_output_pipe(@_);
270
271	if (not defined wantarray) {
272		# Nothing to pepper the possible exception with.
273		_cmd_close($ctx, $fh);
274
275	} elsif (not wantarray) {
276		local $/;
277		my $text = <$fh>;
278		try {
279			_cmd_close($ctx, $fh);
280		} catch Git::Error::Command with {
281			# Pepper with the output:
282			my $E = shift;
283			$E->{'-outputref'} = \$text;
284			throw $E;
285		};
286		return $text;
287
288	} else {
289		my @lines = <$fh>;
290		defined and chomp for @lines;
291		try {
292			_cmd_close($ctx, $fh);
293		} catch Git::Error::Command with {
294			my $E = shift;
295			$E->{'-outputref'} = \@lines;
296			throw $E;
297		};
298		return @lines;
299	}
300}
301
302
303=item command_oneline ( COMMAND [, ARGUMENTS... ] )
304
305=item command_oneline ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
306
307Execute the given C<COMMAND> in the same way as command()
308does but always return a scalar string containing the first line
309of the command's standard output.
310
311=cut
312
313sub command_oneline {
314	my ($fh, $ctx) = command_output_pipe(@_);
315
316	my $line = <$fh>;
317	defined $line and chomp $line;
318	try {
319		_cmd_close($ctx, $fh);
320	} catch Git::Error::Command with {
321		# Pepper with the output:
322		my $E = shift;
323		$E->{'-outputref'} = \$line;
324		throw $E;
325	};
326	return $line;
327}
328
329
330=item command_output_pipe ( COMMAND [, ARGUMENTS... ] )
331
332=item command_output_pipe ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
333
334Execute the given C<COMMAND> in the same way as command()
335does but return a pipe filehandle from which the command output can be
336read.
337
338The function can return C<($pipe, $ctx)> in array context.
339See C<command_close_pipe()> for details.
340
341=cut
342
343sub command_output_pipe {
344	_command_common_pipe('-|', @_);
345}
346
347
348=item command_input_pipe ( COMMAND [, ARGUMENTS... ] )
349
350=item command_input_pipe ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
351
352Execute the given C<COMMAND> in the same way as command_output_pipe()
353does but return an input pipe filehandle instead; the command output
354is not captured.
355
356The function can return C<($pipe, $ctx)> in array context.
357See C<command_close_pipe()> for details.
358
359=cut
360
361sub command_input_pipe {
362	_command_common_pipe('|-', @_);
363}
364
365
366=item command_close_pipe ( PIPE [, CTX ] )
367
368Close the C<PIPE> as returned from C<command_*_pipe()>, checking
369whether the command finished successfully. The optional C<CTX> argument
370is required if you want to see the command name in the error message,
371and it is the second value returned by C<command_*_pipe()> when
372called in array context. The call idiom is:
373
374	my ($fh, $ctx) = $r->command_output_pipe('status');
375	while (<$fh>) { ... }
376	$r->command_close_pipe($fh, $ctx);
377
378Note that you should not rely on whatever actually is in C<CTX>;
379currently it is simply the command name but in future the context might
380have more complicated structure.
381
382=cut
383
384sub command_close_pipe {
385	my ($self, $fh, $ctx) = _maybe_self(@_);
386	$ctx ||= '<unknown>';
387	_cmd_close($ctx, $fh);
388}
389
390=item command_bidi_pipe ( COMMAND [, ARGUMENTS... ] )
391
392Execute the given C<COMMAND> in the same way as command_output_pipe()
393does but return both an input pipe filehandle and an output pipe filehandle.
394
395The function will return C<($pid, $pipe_in, $pipe_out, $ctx)>.
396See C<command_close_bidi_pipe()> for details.
397
398=cut
399
400sub command_bidi_pipe {
401	my ($pid, $in, $out);
402	my ($self) = _maybe_self(@_);
403	local %ENV = %ENV;
404	my $cwd_save = undef;
405	if ($self) {
406		shift;
407		require Cwd;
408		$cwd_save = Cwd::getcwd();
409		_setup_git_cmd_env($self);
410	}
411	require IPC::Open2;
412	$pid = IPC::Open2::open2($in, $out, 'git', @_);
413	chdir($cwd_save) if $cwd_save;
414	return ($pid, $in, $out, join(' ', @_));
415}
416
417=item command_close_bidi_pipe ( PID, PIPE_IN, PIPE_OUT [, CTX] )
418
419Close the C<PIPE_IN> and C<PIPE_OUT> as returned from C<command_bidi_pipe()>,
420checking whether the command finished successfully. The optional C<CTX>
421argument is required if you want to see the command name in the error message,
422and it is the fourth value returned by C<command_bidi_pipe()>.  The call idiom
423is:
424
425	my ($pid, $in, $out, $ctx) = $r->command_bidi_pipe('cat-file --batch-check');
426	print $out "000000000\n";
427	while (<$in>) { ... }
428	$r->command_close_bidi_pipe($pid, $in, $out, $ctx);
429
430Note that you should not rely on whatever actually is in C<CTX>;
431currently it is simply the command name but in future the context might
432have more complicated structure.
433
434C<PIPE_IN> and C<PIPE_OUT> may be C<undef> if they have been closed prior to
435calling this function.  This may be useful in a query-response type of
436commands where caller first writes a query and later reads response, eg:
437
438	my ($pid, $in, $out, $ctx) = $r->command_bidi_pipe('cat-file --batch-check');
439	print $out "000000000\n";
440	close $out;
441	while (<$in>) { ... }
442	$r->command_close_bidi_pipe($pid, $in, undef, $ctx);
443
444This idiom may prevent potential dead locks caused by data sent to the output
445pipe not being flushed and thus not reaching the executed command.
446
447=cut
448
449sub command_close_bidi_pipe {
450	local $?;
451	my ($self, $pid, $in, $out, $ctx) = _maybe_self(@_);
452	_cmd_close($ctx, (grep { defined } ($in, $out)));
453	waitpid $pid, 0;
454	if ($? >> 8) {
455		throw Git::Error::Command($ctx, $? >>8);
456	}
457}
458
459
460=item command_noisy ( COMMAND [, ARGUMENTS... ] )
461
462Execute the given C<COMMAND> in the same way as command() does but do not
463capture the command output - the standard output is not redirected and goes
464to the standard output of the caller application.
465
466While the method is called command_noisy(), you might want to as well use
467it for the most silent Git commands which you know will never pollute your
468stdout but you want to avoid the overhead of the pipe setup when calling them.
469
470The function returns only after the command has finished running.
471
472=cut
473
474sub command_noisy {
475	my ($self, $cmd, @args) = _maybe_self(@_);
476	_check_valid_cmd($cmd);
477
478	my $pid = fork;
479	if (not defined $pid) {
480		throw Error::Simple("fork failed: $!");
481	} elsif ($pid == 0) {
482		_cmd_exec($self, $cmd, @args);
483	}
484	if (waitpid($pid, 0) > 0 and $?>>8 != 0) {
485		throw Git::Error::Command(join(' ', $cmd, @args), $? >> 8);
486	}
487}
488
489
490=item version ()
491
492Return the Git version in use.
493
494=cut
495
496sub version {
497	my $verstr = command_oneline('--version');
498	$verstr =~ s/^git version //;
499	$verstr;
500}
501
502
503=item exec_path ()
504
505Return path to the Git sub-command executables (the same as
506C<git --exec-path>). Useful mostly only internally.
507
508=cut
509
510sub exec_path { command_oneline('--exec-path') }
511
512
513=item html_path ()
514
515Return path to the Git html documentation (the same as
516C<git --html-path>). Useful mostly only internally.
517
518=cut
519
520sub html_path { command_oneline('--html-path') }
521
522
523=item get_tz_offset ( TIME )
524
525Return the time zone offset from GMT in the form +/-HHMM where HH is
526the number of hours from GMT and MM is the number of minutes.  This is
527the equivalent of what strftime("%z", ...) would provide on a GNU
528platform.
529
530If TIME is not supplied, the current local time is used.
531
532=cut
533
534sub get_tz_offset {
535	# some systems don't handle or mishandle %z, so be creative.
536	my $t = shift || time;
537	my @t = localtime($t);
538	$t[5] += 1900;
539	require Time::Local;
540	my $gm = Time::Local::timegm(@t);
541	my $sign = qw( + + - )[ $gm <=> $t ];
542	return sprintf("%s%02d%02d", $sign, (gmtime(abs($t - $gm)))[2,1]);
543}
544
545=item get_record ( FILEHANDLE, INPUT_RECORD_SEPARATOR )
546
547Read one record from FILEHANDLE delimited by INPUT_RECORD_SEPARATOR,
548removing any trailing INPUT_RECORD_SEPARATOR.
549
550=cut
551
552sub get_record {
553	my ($fh, $rs) = @_;
554	local $/ = $rs;
555	my $rec = <$fh>;
556	chomp $rec if defined $rec;
557	$rec;
558}
559
560=item prompt ( PROMPT , ISPASSWORD  )
561
562Query user C<PROMPT> and return answer from user.
563
564Honours GIT_ASKPASS and SSH_ASKPASS environment variables for querying
565the user. If no *_ASKPASS variable is set or an error occurred,
566the terminal is tried as a fallback.
567If C<ISPASSWORD> is set and true, the terminal disables echo.
568
569=cut
570
571sub prompt {
572	my ($prompt, $isPassword) = @_;
573	my $ret;
574	if (exists $ENV{'GIT_ASKPASS'}) {
575		$ret = _prompt($ENV{'GIT_ASKPASS'}, $prompt);
576	}
577	if (!defined $ret && exists $ENV{'SSH_ASKPASS'}) {
578		$ret = _prompt($ENV{'SSH_ASKPASS'}, $prompt);
579	}
580	if (!defined $ret) {
581		print STDERR $prompt;
582		STDERR->flush;
583		if (defined $isPassword && $isPassword) {
584			require Term::ReadKey;
585			Term::ReadKey::ReadMode('noecho');
586			$ret = '';
587			while (defined(my $key = Term::ReadKey::ReadKey(0))) {
588				last if $key =~ /[\012\015]/; # \n\r
589				$ret .= $key;
590			}
591			Term::ReadKey::ReadMode('restore');
592			print STDERR "\n";
593			STDERR->flush;
594		} else {
595			chomp($ret = <STDIN>);
596		}
597	}
598	return $ret;
599}
600
601sub _prompt {
602	my ($askpass, $prompt) = @_;
603	return unless length $askpass;
604	$prompt =~ s/\n/ /g;
605	my $ret;
606	open my $fh, "-|", $askpass, $prompt or return;
607	$ret = <$fh>;
608	$ret =~ s/[\015\012]//g; # strip \r\n, chomp does not work on all systems (i.e. windows) as expected
609	close ($fh);
610	return $ret;
611}
612
613=item repo_path ()
614
615Return path to the git repository. Must be called on a repository instance.
616
617=cut
618
619sub repo_path { $_[0]->{opts}->{Repository} }
620
621
622=item wc_path ()
623
624Return path to the working copy. Must be called on a repository instance.
625
626=cut
627
628sub wc_path { $_[0]->{opts}->{WorkingCopy} }
629
630
631=item wc_subdir ()
632
633Return path to the subdirectory inside of a working copy. Must be called
634on a repository instance.
635
636=cut
637
638sub wc_subdir { $_[0]->{opts}->{WorkingSubdir} ||= '' }
639
640
641=item wc_chdir ( SUBDIR )
642
643Change the working copy subdirectory to work within. The C<SUBDIR> is
644relative to the working copy root directory (not the current subdirectory).
645Must be called on a repository instance attached to a working copy
646and the directory must exist.
647
648=cut
649
650sub wc_chdir {
651	my ($self, $subdir) = @_;
652	$self->wc_path()
653		or throw Error::Simple("bare repository");
654
655	-d $self->wc_path().'/'.$subdir
656		or throw Error::Simple("subdir not found: $subdir $!");
657	# Of course we will not "hold" the subdirectory so anyone
658	# can delete it now and we will never know. But at least we tried.
659
660	$self->{opts}->{WorkingSubdir} = $subdir;
661}
662
663
664=item config ( VARIABLE )
665
666Retrieve the configuration C<VARIABLE> in the same manner as C<config>
667does. In scalar context requires the variable to be set only one time
668(exception is thrown otherwise), in array context returns allows the
669variable to be set multiple times and returns all the values.
670
671=cut
672
673sub config {
674	return _config_common({}, @_);
675}
676
677
678=item config_bool ( VARIABLE )
679
680Retrieve the bool configuration C<VARIABLE>. The return value
681is usable as a boolean in perl (and C<undef> if it's not defined,
682of course).
683
684=cut
685
686sub config_bool {
687	my $val = scalar _config_common({'kind' => '--bool'}, @_);
688
689	# Do not rewrite this as return (defined $val && $val eq 'true')
690	# as some callers do care what kind of falsehood they receive.
691	if (!defined $val) {
692		return undef;
693	} else {
694		return $val eq 'true';
695	}
696}
697
698
699=item config_path ( VARIABLE )
700
701Retrieve the path configuration C<VARIABLE>. The return value
702is an expanded path or C<undef> if it's not defined.
703
704=cut
705
706sub config_path {
707	return _config_common({'kind' => '--path'}, @_);
708}
709
710
711=item config_int ( VARIABLE )
712
713Retrieve the integer configuration C<VARIABLE>. The return value
714is simple decimal number.  An optional value suffix of 'k', 'm',
715or 'g' in the config file will cause the value to be multiplied
716by 1024, 1048576 (1024^2), or 1073741824 (1024^3) prior to output.
717It would return C<undef> if configuration variable is not defined.
718
719=cut
720
721sub config_int {
722	return scalar _config_common({'kind' => '--int'}, @_);
723}
724
725=item config_regexp ( RE )
726
727Retrieve the list of configuration key names matching the regular
728expression C<RE>. The return value is a list of strings matching
729this regex.
730
731=cut
732
733sub config_regexp {
734	my ($self, $regex) = _maybe_self(@_);
735	try {
736		my @cmd = ('config', '--name-only', '--get-regexp', $regex);
737		unshift @cmd, $self if $self;
738		my @matches = command(@cmd);
739		return @matches;
740	} catch Git::Error::Command with {
741		my $E = shift;
742		if ($E->value() == 1) {
743			my @matches = ();
744			return @matches;
745		} else {
746			throw $E;
747		}
748	};
749}
750
751# Common subroutine to implement bulk of what the config* family of methods
752# do. This currently wraps command('config') so it is not so fast.
753sub _config_common {
754	my ($opts) = shift @_;
755	my ($self, $var) = _maybe_self(@_);
756
757	try {
758		my @cmd = ('config', $opts->{'kind'} ? $opts->{'kind'} : ());
759		unshift @cmd, $self if $self;
760		if (wantarray) {
761			return command(@cmd, '--get-all', $var);
762		} else {
763			return command_oneline(@cmd, '--get', $var);
764		}
765	} catch Git::Error::Command with {
766		my $E = shift;
767		if ($E->value() == 1) {
768			# Key not found.
769			return;
770		} else {
771			throw $E;
772		}
773	};
774}
775
776=item get_colorbool ( NAME )
777
778Finds if color should be used for NAMEd operation from the configuration,
779and returns boolean (true for "use color", false for "do not use color").
780
781=cut
782
783sub get_colorbool {
784	my ($self, $var) = @_;
785	my $stdout_to_tty = (-t STDOUT) ? "true" : "false";
786	my $use_color = $self->command_oneline('config', '--get-colorbool',
787					       $var, $stdout_to_tty);
788	return ($use_color eq 'true');
789}
790
791=item get_color ( SLOT, COLOR )
792
793Finds color for SLOT from the configuration, while defaulting to COLOR,
794and returns the ANSI color escape sequence:
795
796	print $repo->get_color("color.interactive.prompt", "underline blue white");
797	print "some text";
798	print $repo->get_color("", "normal");
799
800=cut
801
802sub get_color {
803	my ($self, $slot, $default) = @_;
804	my $color = $self->command_oneline('config', '--get-color', $slot, $default);
805	if (!defined $color) {
806		$color = "";
807	}
808	return $color;
809}
810
811=item remote_refs ( REPOSITORY [, GROUPS [, REFGLOBS ] ] )
812
813This function returns a hashref of refs stored in a given remote repository.
814The hash is in the format C<refname =\> hash>. For tags, the C<refname> entry
815contains the tag object while a C<refname^{}> entry gives the tagged objects.
816
817C<REPOSITORY> has the same meaning as the appropriate C<git-ls-remote>
818argument; either a URL or a remote name (if called on a repository instance).
819C<GROUPS> is an optional arrayref that can contain 'tags' to return all the
820tags and/or 'heads' to return all the heads. C<REFGLOB> is an optional array
821of strings containing a shell-like glob to further limit the refs returned in
822the hash; the meaning is again the same as the appropriate C<git-ls-remote>
823argument.
824
825This function may or may not be called on a repository instance. In the former
826case, remote names as defined in the repository are recognized as repository
827specifiers.
828
829=cut
830
831sub remote_refs {
832	my ($self, $repo, $groups, $refglobs) = _maybe_self(@_);
833	my @args;
834	if (ref $groups eq 'ARRAY') {
835		foreach (@$groups) {
836			if ($_ eq 'heads') {
837				push (@args, '--heads');
838			} elsif ($_ eq 'tags') {
839				push (@args, '--tags');
840			} else {
841				# Ignore unknown groups for future
842				# compatibility
843			}
844		}
845	}
846	push (@args, $repo);
847	if (ref $refglobs eq 'ARRAY') {
848		push (@args, @$refglobs);
849	}
850
851	my @self = $self ? ($self) : (); # Ultra trickery
852	my ($fh, $ctx) = Git::command_output_pipe(@self, 'ls-remote', @args);
853	my %refs;
854	while (<$fh>) {
855		chomp;
856		my ($hash, $ref) = split(/\t/, $_, 2);
857		$refs{$ref} = $hash;
858	}
859	Git::command_close_pipe(@self, $fh, $ctx);
860	return \%refs;
861}
862
863
864=item ident ( TYPE | IDENTSTR )
865
866=item ident_person ( TYPE | IDENTSTR | IDENTARRAY )
867
868This suite of functions retrieves and parses ident information, as stored
869in the commit and tag objects or produced by C<var GIT_type_IDENT> (thus
870C<TYPE> can be either I<author> or I<committer>; case is insignificant).
871
872The C<ident> method retrieves the ident information from C<git var>
873and either returns it as a scalar string or as an array with the fields parsed.
874Alternatively, it can take a prepared ident string (e.g. from the commit
875object) and just parse it.
876
877C<ident_person> returns the person part of the ident - name and email;
878it can take the same arguments as C<ident> or the array returned by C<ident>.
879
880The synopsis is like:
881
882	my ($name, $email, $time_tz) = ident('author');
883	"$name <$email>" eq ident_person('author');
884	"$name <$email>" eq ident_person($name);
885	$time_tz =~ /^\d+ [+-]\d{4}$/;
886
887=cut
888
889sub ident {
890	my ($self, $type) = _maybe_self(@_);
891	my $identstr;
892	if (lc $type eq lc 'committer' or lc $type eq lc 'author') {
893		my @cmd = ('var', 'GIT_'.uc($type).'_IDENT');
894		unshift @cmd, $self if $self;
895		$identstr = command_oneline(@cmd);
896	} else {
897		$identstr = $type;
898	}
899	if (wantarray) {
900		return $identstr =~ /^(.*) <(.*)> (\d+ [+-]\d{4})$/;
901	} else {
902		return $identstr;
903	}
904}
905
906sub ident_person {
907	my ($self, @ident) = _maybe_self(@_);
908	$#ident == 0 and @ident = $self ? $self->ident($ident[0]) : ident($ident[0]);
909	return "$ident[0] <$ident[1]>";
910}
911
912=item hash_object ( TYPE, FILENAME )
913
914Compute the SHA1 object id of the given C<FILENAME> considering it is
915of the C<TYPE> object type (C<blob>, C<commit>, C<tree>).
916
917The method can be called without any instance or on a specified Git repository,
918it makes zero difference.
919
920The function returns the SHA1 hash.
921
922=cut
923
924# TODO: Support for passing FILEHANDLE instead of FILENAME
925sub hash_object {
926	my ($self, $type, $file) = _maybe_self(@_);
927	command_oneline('hash-object', '-t', $type, $file);
928}
929
930
931=item hash_and_insert_object ( FILENAME )
932
933Compute the SHA1 object id of the given C<FILENAME> and add the object to the
934object database.
935
936The function returns the SHA1 hash.
937
938=cut
939
940# TODO: Support for passing FILEHANDLE instead of FILENAME
941sub hash_and_insert_object {
942	my ($self, $filename) = @_;
943
944	carp "Bad filename \"$filename\"" if $filename =~ /[\r\n]/;
945
946	$self->_open_hash_and_insert_object_if_needed();
947	my ($in, $out) = ($self->{hash_object_in}, $self->{hash_object_out});
948
949	unless (print $out $filename, "\n") {
950		$self->_close_hash_and_insert_object();
951		throw Error::Simple("out pipe went bad");
952	}
953
954	chomp(my $hash = <$in>);
955	unless (defined($hash)) {
956		$self->_close_hash_and_insert_object();
957		throw Error::Simple("in pipe went bad");
958	}
959
960	return $hash;
961}
962
963sub _open_hash_and_insert_object_if_needed {
964	my ($self) = @_;
965
966	return if defined($self->{hash_object_pid});
967
968	($self->{hash_object_pid}, $self->{hash_object_in},
969	 $self->{hash_object_out}, $self->{hash_object_ctx}) =
970		$self->command_bidi_pipe(qw(hash-object -w --stdin-paths --no-filters));
971}
972
973sub _close_hash_and_insert_object {
974	my ($self) = @_;
975
976	return unless defined($self->{hash_object_pid});
977
978	my @vars = map { 'hash_object_' . $_ } qw(pid in out ctx);
979
980	command_close_bidi_pipe(@$self{@vars});
981	delete @$self{@vars};
982}
983
984=item cat_blob ( SHA1, FILEHANDLE )
985
986Prints the contents of the blob identified by C<SHA1> to C<FILEHANDLE> and
987returns the number of bytes printed.
988
989=cut
990
991sub cat_blob {
992	my ($self, $sha1, $fh) = @_;
993
994	$self->_open_cat_blob_if_needed();
995	my ($in, $out) = ($self->{cat_blob_in}, $self->{cat_blob_out});
996
997	unless (print $out $sha1, "\n") {
998		$self->_close_cat_blob();
999		throw Error::Simple("out pipe went bad");
1000	}
1001
1002	my $description = <$in>;
1003	if ($description =~ / missing$/) {
1004		carp "$sha1 doesn't exist in the repository";
1005		return -1;
1006	}
1007
1008	if ($description !~ /^[0-9a-fA-F]{40}(?:[0-9a-fA-F]{24})? \S+ (\d+)$/) {
1009		carp "Unexpected result returned from git cat-file";
1010		return -1;
1011	}
1012
1013	my $size = $1;
1014
1015	my $blob;
1016	my $bytesLeft = $size;
1017
1018	while (1) {
1019		last unless $bytesLeft;
1020
1021		my $bytesToRead = $bytesLeft < 1024 ? $bytesLeft : 1024;
1022		my $read = read($in, $blob, $bytesToRead);
1023		unless (defined($read)) {
1024			$self->_close_cat_blob();
1025			throw Error::Simple("in pipe went bad");
1026		}
1027		unless (print $fh $blob) {
1028			$self->_close_cat_blob();
1029			throw Error::Simple("couldn't write to passed in filehandle");
1030		}
1031		$bytesLeft -= $read;
1032	}
1033
1034	# Skip past the trailing newline.
1035	my $newline;
1036	my $read = read($in, $newline, 1);
1037	unless (defined($read)) {
1038		$self->_close_cat_blob();
1039		throw Error::Simple("in pipe went bad");
1040	}
1041	unless ($read == 1 && $newline eq "\n") {
1042		$self->_close_cat_blob();
1043		throw Error::Simple("didn't find newline after blob");
1044	}
1045
1046	return $size;
1047}
1048
1049sub _open_cat_blob_if_needed {
1050	my ($self) = @_;
1051
1052	return if defined($self->{cat_blob_pid});
1053
1054	($self->{cat_blob_pid}, $self->{cat_blob_in},
1055	 $self->{cat_blob_out}, $self->{cat_blob_ctx}) =
1056		$self->command_bidi_pipe(qw(cat-file --batch));
1057}
1058
1059sub _close_cat_blob {
1060	my ($self) = @_;
1061
1062	return unless defined($self->{cat_blob_pid});
1063
1064	my @vars = map { 'cat_blob_' . $_ } qw(pid in out ctx);
1065
1066	command_close_bidi_pipe(@$self{@vars});
1067	delete @$self{@vars};
1068}
1069
1070
1071=item credential_read( FILEHANDLE )
1072
1073Reads credential key-value pairs from C<FILEHANDLE>.  Reading stops at EOF or
1074when an empty line is encountered.  Each line must be of the form C<key=value>
1075with a non-empty key.  Function returns hash with all read values.  Any white
1076space (other than new-line character) is preserved.
1077
1078=cut
1079
1080sub credential_read {
1081	my ($self, $reader) = _maybe_self(@_);
1082	my %credential;
1083	while (<$reader>) {
1084		chomp;
1085		if ($_ eq '') {
1086			last;
1087		} elsif (!/^([^=]+)=(.*)$/) {
1088			throw Error::Simple("unable to parse git credential data:\n$_");
1089		}
1090		$credential{$1} = $2;
1091	}
1092	return %credential;
1093}
1094
1095=item credential_write( FILEHANDLE, CREDENTIAL_HASHREF )
1096
1097Writes credential key-value pairs from hash referenced by
1098C<CREDENTIAL_HASHREF> to C<FILEHANDLE>.  Keys and values cannot contain
1099new-lines or NUL bytes characters, and key cannot contain equal signs nor be
1100empty (if they do Error::Simple is thrown).  Any white space is preserved.  If
1101value for a key is C<undef>, it will be skipped.
1102
1103If C<'url'> key exists it will be written first.  (All the other key-value
1104pairs are written in sorted order but you should not depend on that).  Once
1105all lines are written, an empty line is printed.
1106
1107=cut
1108
1109sub credential_write {
1110	my ($self, $writer, $credential) = _maybe_self(@_);
1111	my ($key, $value);
1112
1113	# Check if $credential is valid prior to writing anything
1114	while (($key, $value) = each %$credential) {
1115		if (!defined $key || !length $key) {
1116			throw Error::Simple("credential key empty or undefined");
1117		} elsif ($key =~ /[=\n\0]/) {
1118			throw Error::Simple("credential key contains invalid characters: $key");
1119		} elsif (defined $value && $value =~ /[\n\0]/) {
1120			throw Error::Simple("credential value for key=$key contains invalid characters: $value");
1121		}
1122	}
1123
1124	for $key (sort {
1125		# url overwrites other fields, so it must come first
1126		return -1 if $a eq 'url';
1127		return  1 if $b eq 'url';
1128		return $a cmp $b;
1129	} keys %$credential) {
1130		if (defined $credential->{$key}) {
1131			print $writer $key, '=', $credential->{$key}, "\n";
1132		}
1133	}
1134	print $writer "\n";
1135}
1136
1137sub _credential_run {
1138	my ($self, $credential, $op) = _maybe_self(@_);
1139	my ($pid, $reader, $writer, $ctx) = command_bidi_pipe('credential', $op);
1140
1141	credential_write $writer, $credential;
1142	close $writer;
1143
1144	if ($op eq "fill") {
1145		%$credential = credential_read $reader;
1146	}
1147	if (<$reader>) {
1148		throw Error::Simple("unexpected output from git credential $op response:\n$_\n");
1149	}
1150
1151	command_close_bidi_pipe($pid, $reader, undef, $ctx);
1152}
1153
1154=item credential( CREDENTIAL_HASHREF [, OPERATION ] )
1155
1156=item credential( CREDENTIAL_HASHREF, CODE )
1157
1158Executes C<git credential> for a given set of credentials and specified
1159operation.  In both forms C<CREDENTIAL_HASHREF> needs to be a reference to
1160a hash which stores credentials.  Under certain conditions the hash can
1161change.
1162
1163In the first form, C<OPERATION> can be C<'fill'>, C<'approve'> or C<'reject'>,
1164and function will execute corresponding C<git credential> sub-command.  If
1165it's omitted C<'fill'> is assumed.  In case of C<'fill'> the values stored in
1166C<CREDENTIAL_HASHREF> will be changed to the ones returned by the C<git
1167credential fill> command.  The usual usage would look something like:
1168
1169	my %cred = (
1170		'protocol' => 'https',
1171		'host' => 'example.com',
1172		'username' => 'bob'
1173	);
1174	Git::credential \%cred;
1175	if (try_to_authenticate($cred{'username'}, $cred{'password'})) {
1176		Git::credential \%cred, 'approve';
1177		... do more stuff ...
1178	} else {
1179		Git::credential \%cred, 'reject';
1180	}
1181
1182In the second form, C<CODE> needs to be a reference to a subroutine.  The
1183function will execute C<git credential fill> to fill the provided credential
1184hash, then call C<CODE> with C<CREDENTIAL_HASHREF> as the sole argument.  If
1185C<CODE>'s return value is defined, the function will execute C<git credential
1186approve> (if return value yields true) or C<git credential reject> (if return
1187value is false).  If the return value is undef, nothing at all is executed;
1188this is useful, for example, if the credential could neither be verified nor
1189rejected due to an unrelated network error.  The return value is the same as
1190what C<CODE> returns.  With this form, the usage might look as follows:
1191
1192	if (Git::credential {
1193		'protocol' => 'https',
1194		'host' => 'example.com',
1195		'username' => 'bob'
1196	}, sub {
1197		my $cred = shift;
1198		return !!try_to_authenticate($cred->{'username'},
1199		                             $cred->{'password'});
1200	}) {
1201		... do more stuff ...
1202	}
1203
1204=cut
1205
1206sub credential {
1207	my ($self, $credential, $op_or_code) = (_maybe_self(@_), 'fill');
1208
1209	if ('CODE' eq ref $op_or_code) {
1210		_credential_run $credential, 'fill';
1211		my $ret = $op_or_code->($credential);
1212		if (defined $ret) {
1213			_credential_run $credential, $ret ? 'approve' : 'reject';
1214		}
1215		return $ret;
1216	} else {
1217		_credential_run $credential, $op_or_code;
1218	}
1219}
1220
1221{ # %TEMP_* Lexical Context
1222
1223my (%TEMP_FILEMAP, %TEMP_FILES);
1224
1225=item temp_acquire ( NAME )
1226
1227Attempts to retrieve the temporary file mapped to the string C<NAME>. If an
1228associated temp file has not been created this session or was closed, it is
1229created, cached, and set for autoflush and binmode.
1230
1231Internally locks the file mapped to C<NAME>. This lock must be released with
1232C<temp_release()> when the temp file is no longer needed. Subsequent attempts
1233to retrieve temporary files mapped to the same C<NAME> while still locked will
1234cause an error. This locking mechanism provides a weak guarantee and is not
1235threadsafe. It does provide some error checking to help prevent temp file refs
1236writing over one another.
1237
1238In general, the L<File::Handle> returned should not be closed by consumers as
1239it defeats the purpose of this caching mechanism. If you need to close the temp
1240file handle, then you should use L<File::Temp> or another temp file faculty
1241directly. If a handle is closed and then requested again, then a warning will
1242issue.
1243
1244=cut
1245
1246sub temp_acquire {
1247	my $temp_fd = _temp_cache(@_);
1248
1249	$TEMP_FILES{$temp_fd}{locked} = 1;
1250	$temp_fd;
1251}
1252
1253=item temp_is_locked ( NAME )
1254
1255Returns true if the internal lock created by a previous C<temp_acquire()>
1256call with C<NAME> is still in effect.
1257
1258When temp_acquire is called on a C<NAME>, it internally locks the temporary
1259file mapped to C<NAME>.  That lock will not be released until C<temp_release()>
1260is called with either the original C<NAME> or the L<File::Handle> that was
1261returned from the original call to temp_acquire.
1262
1263Subsequent attempts to call C<temp_acquire()> with the same C<NAME> will fail
1264unless there has been an intervening C<temp_release()> call for that C<NAME>
1265(or its corresponding L<File::Handle> that was returned by the original
1266C<temp_acquire()> call).
1267
1268If true is returned by C<temp_is_locked()> for a C<NAME>, an attempt to
1269C<temp_acquire()> the same C<NAME> will cause an error unless
1270C<temp_release> is first called on that C<NAME> (or its corresponding
1271L<File::Handle> that was returned by the original C<temp_acquire()> call).
1272
1273=cut
1274
1275sub temp_is_locked {
1276	my ($self, $name) = _maybe_self(@_);
1277	my $temp_fd = \$TEMP_FILEMAP{$name};
1278
1279	defined $$temp_fd && $$temp_fd->opened && $TEMP_FILES{$$temp_fd}{locked};
1280}
1281
1282=item temp_release ( NAME )
1283
1284=item temp_release ( FILEHANDLE )
1285
1286Releases a lock acquired through C<temp_acquire()>. Can be called either with
1287the C<NAME> mapping used when acquiring the temp file or with the C<FILEHANDLE>
1288referencing a locked temp file.
1289
1290Warns if an attempt is made to release a file that is not locked.
1291
1292The temp file will be truncated before being released. This can help to reduce
1293disk I/O where the system is smart enough to detect the truncation while data
1294is in the output buffers. Beware that after the temp file is released and
1295truncated, any operations on that file may fail miserably until it is
1296re-acquired. All contents are lost between each release and acquire mapped to
1297the same string.
1298
1299=cut
1300
1301sub temp_release {
1302	my ($self, $temp_fd, $trunc) = _maybe_self(@_);
1303
1304	if (exists $TEMP_FILEMAP{$temp_fd}) {
1305		$temp_fd = $TEMP_FILES{$temp_fd};
1306	}
1307	unless ($TEMP_FILES{$temp_fd}{locked}) {
1308		carp "Attempt to release temp file '",
1309			$temp_fd, "' that has not been locked";
1310	}
1311	temp_reset($temp_fd) if $trunc and $temp_fd->opened;
1312
1313	$TEMP_FILES{$temp_fd}{locked} = 0;
1314	undef;
1315}
1316
1317sub _temp_cache {
1318	my ($self, $name) = _maybe_self(@_);
1319
1320	my $temp_fd = \$TEMP_FILEMAP{$name};
1321	if (defined $$temp_fd and $$temp_fd->opened) {
1322		if ($TEMP_FILES{$$temp_fd}{locked}) {
1323			throw Error::Simple("Temp file with moniker '" .
1324				$name . "' already in use");
1325		}
1326	} else {
1327		if (defined $$temp_fd) {
1328			# then we're here because of a closed handle.
1329			carp "Temp file '", $name,
1330				"' was closed. Opening replacement.";
1331		}
1332		my $fname;
1333
1334		my $tmpdir;
1335		if (defined $self) {
1336			$tmpdir = $self->repo_path();
1337		}
1338
1339		my $n = $name;
1340		$n =~ s/\W/_/g; # no strange chars
1341
1342		require File::Temp;
1343		($$temp_fd, $fname) = File::Temp::tempfile(
1344			"Git_${n}_XXXXXX", UNLINK => 1, DIR => $tmpdir,
1345			) or throw Error::Simple("couldn't open new temp file");
1346
1347		$$temp_fd->autoflush;
1348		binmode $$temp_fd;
1349		$TEMP_FILES{$$temp_fd}{fname} = $fname;
1350	}
1351	$$temp_fd;
1352}
1353
1354=item temp_reset ( FILEHANDLE )
1355
1356Truncates and resets the position of the C<FILEHANDLE>.
1357
1358=cut
1359
1360sub temp_reset {
1361	my ($self, $temp_fd) = _maybe_self(@_);
1362
1363	truncate $temp_fd, 0
1364		or throw Error::Simple("couldn't truncate file");
1365	sysseek($temp_fd, 0, Fcntl::SEEK_SET()) and seek($temp_fd, 0, Fcntl::SEEK_SET())
1366		or throw Error::Simple("couldn't seek to beginning of file");
1367	sysseek($temp_fd, 0, Fcntl::SEEK_CUR()) == 0 and tell($temp_fd) == 0
1368		or throw Error::Simple("expected file position to be reset");
1369}
1370
1371=item temp_path ( NAME )
1372
1373=item temp_path ( FILEHANDLE )
1374
1375Returns the filename associated with the given tempfile.
1376
1377=cut
1378
1379sub temp_path {
1380	my ($self, $temp_fd) = _maybe_self(@_);
1381
1382	if (exists $TEMP_FILEMAP{$temp_fd}) {
1383		$temp_fd = $TEMP_FILEMAP{$temp_fd};
1384	}
1385	$TEMP_FILES{$temp_fd}{fname};
1386}
1387
1388sub END {
1389	unlink values %TEMP_FILEMAP if %TEMP_FILEMAP;
1390}
1391
1392} # %TEMP_* Lexical Context
1393
1394=item prefix_lines ( PREFIX, STRING [, STRING... ])
1395
1396Prefixes lines in C<STRING> with C<PREFIX>.
1397
1398=cut
1399
1400sub prefix_lines {
1401	my $prefix = shift;
1402	my $string = join("\n", @_);
1403	$string =~ s/^/$prefix/mg;
1404	return $string;
1405}
1406
1407=item unquote_path ( PATH )
1408
1409Unquote a quoted path containing c-escapes as returned by ls-files etc.
1410when not using -z or when parsing the output of diff -u.
1411
1412=cut
1413
1414{
1415	my %cquote_map = (
1416		"a" => chr(7),
1417		"b" => chr(8),
1418		"t" => chr(9),
1419		"n" => chr(10),
1420		"v" => chr(11),
1421		"f" => chr(12),
1422		"r" => chr(13),
1423		"\\" => "\\",
1424		"\042" => "\042",
1425	);
1426
1427	sub unquote_path {
1428		local ($_) = @_;
1429		my ($retval, $remainder);
1430		if (!/^\042(.*)\042$/) {
1431			return $_;
1432		}
1433		($_, $retval) = ($1, "");
1434		while (/^([^\\]*)\\(.*)$/) {
1435			$remainder = $2;
1436			$retval .= $1;
1437			for ($remainder) {
1438				if (/^([0-3][0-7][0-7])(.*)$/) {
1439					$retval .= chr(oct($1));
1440					$_ = $2;
1441					last;
1442				}
1443				if (/^([\\\042abtnvfr])(.*)$/) {
1444					$retval .= $cquote_map{$1};
1445					$_ = $2;
1446					last;
1447				}
1448				# This is malformed
1449				throw Error::Simple("invalid quoted path $_[0]");
1450			}
1451			$_ = $remainder;
1452		}
1453		$retval .= $_;
1454		return $retval;
1455	}
1456}
1457
1458=item get_comment_line_char ( )
1459
1460Gets the core.commentchar configuration value.
1461The value falls-back to '#' if core.commentchar is set to 'auto'.
1462
1463=cut
1464
1465sub get_comment_line_char {
1466	my $comment_line_char = config("core.commentchar") || '#';
1467	$comment_line_char = '#' if ($comment_line_char eq 'auto');
1468	$comment_line_char = '#' if (length($comment_line_char) != 1);
1469	return $comment_line_char;
1470}
1471
1472=item comment_lines ( STRING [, STRING... ])
1473
1474Comments lines following core.commentchar configuration.
1475
1476=cut
1477
1478sub comment_lines {
1479	my $comment_line_char = get_comment_line_char;
1480	return prefix_lines("$comment_line_char ", @_);
1481}
1482
1483=back
1484
1485=head1 ERROR HANDLING
1486
1487All functions are supposed to throw Perl exceptions in case of errors.
1488See the L<Error> module on how to catch those. Most exceptions are mere
1489L<Error::Simple> instances.
1490
1491However, the C<command()>, C<command_oneline()> and C<command_noisy()>
1492functions suite can throw C<Git::Error::Command> exceptions as well: those are
1493thrown when the external command returns an error code and contain the error
1494code as well as access to the captured command's output. The exception class
1495provides the usual C<stringify> and C<value> (command's exit code) methods and
1496in addition also a C<cmd_output> method that returns either an array or a
1497string with the captured command output (depending on the original function
1498call context; C<command_noisy()> returns C<undef>) and $<cmdline> which
1499returns the command and its arguments (but without proper quoting).
1500
1501Note that the C<command_*_pipe()> functions cannot throw this exception since
1502it has no idea whether the command failed or not. You will only find out
1503at the time you C<close> the pipe; if you want to have that automated,
1504use C<command_close_pipe()>, which can throw the exception.
1505
1506=cut
1507
1508{
1509	package Git::Error::Command;
1510
1511	@Git::Error::Command::ISA = qw(Error);
1512
1513	sub new {
1514		my $self = shift;
1515		my $cmdline = '' . shift;
1516		my $value = 0 + shift;
1517		my $outputref = shift;
1518		my(@args) = ();
1519
1520		local $Error::Depth = $Error::Depth + 1;
1521
1522		push(@args, '-cmdline', $cmdline);
1523		push(@args, '-value', $value);
1524		push(@args, '-outputref', $outputref);
1525
1526		$self->SUPER::new(-text => 'command returned error', @args);
1527	}
1528
1529	sub stringify {
1530		my $self = shift;
1531		my $text = $self->SUPER::stringify;
1532		$self->cmdline() . ': ' . $text . ': ' . $self->value() . "\n";
1533	}
1534
1535	sub cmdline {
1536		my $self = shift;
1537		$self->{'-cmdline'};
1538	}
1539
1540	sub cmd_output {
1541		my $self = shift;
1542		my $ref = $self->{'-outputref'};
1543		defined $ref or undef;
1544		if (ref $ref eq 'ARRAY') {
1545			return @$ref;
1546		} else { # SCALAR
1547			return $$ref;
1548		}
1549	}
1550}
1551
1552=over 4
1553
1554=item git_cmd_try { CODE } ERRMSG
1555
1556This magical statement will automatically catch any C<Git::Error::Command>
1557exceptions thrown by C<CODE> and make your program die with C<ERRMSG>
1558on its lips; the message will have %s substituted for the command line
1559and %d for the exit status. This statement is useful mostly for producing
1560more user-friendly error messages.
1561
1562In case of no exception caught the statement returns C<CODE>'s return value.
1563
1564Note that this is the only auto-exported function.
1565
1566=cut
1567
1568sub git_cmd_try(&$) {
1569	my ($code, $errmsg) = @_;
1570	my @result;
1571	my $err;
1572	my $array = wantarray;
1573	try {
1574		if ($array) {
1575			@result = &$code;
1576		} else {
1577			$result[0] = &$code;
1578		}
1579	} catch Git::Error::Command with {
1580		my $E = shift;
1581		$err = $errmsg;
1582		$err =~ s/\%s/$E->cmdline()/ge;
1583		$err =~ s/\%d/$E->value()/ge;
1584		# We can't croak here since Error.pm would mangle
1585		# that to Error::Simple.
1586	};
1587	$err and croak $err;
1588	return $array ? @result : $result[0];
1589}
1590
1591
1592=back
1593
1594=head1 COPYRIGHT
1595
1596Copyright 2006 by Petr Baudis E<lt>pasky@suse.czE<gt>.
1597
1598This module is free software; it may be used, copied, modified
1599and distributed under the terms of the GNU General Public Licence,
1600either version 2, or (at your option) any later version.
1601
1602=cut
1603
1604
1605# Take raw method argument list and return ($obj, @args) in case
1606# the method was called upon an instance and (undef, @args) if
1607# it was called directly.
1608sub _maybe_self {
1609	UNIVERSAL::isa($_[0], 'Git') ? @_ : (undef, @_);
1610}
1611
1612# Check if the command id is something reasonable.
1613sub _check_valid_cmd {
1614	my ($cmd) = @_;
1615	$cmd =~ /^[a-z0-9A-Z_-]+$/ or throw Error::Simple("bad command: $cmd");
1616}
1617
1618# Common backend for the pipe creators.
1619sub _command_common_pipe {
1620	my $direction = shift;
1621	my ($self, @p) = _maybe_self(@_);
1622	my (%opts, $cmd, @args);
1623	if (ref $p[0]) {
1624		($cmd, @args) = @{shift @p};
1625		%opts = ref $p[0] ? %{$p[0]} : @p;
1626	} else {
1627		($cmd, @args) = @p;
1628	}
1629	_check_valid_cmd($cmd);
1630
1631	my $fh;
1632	if ($^O eq 'MSWin32') {
1633		# ActiveState Perl
1634		#defined $opts{STDERR} and
1635		#	warn 'ignoring STDERR option - running w/ ActiveState';
1636		$direction eq '-|' or
1637			die 'input pipe for ActiveState not implemented';
1638		# the strange construction with *ACPIPE is just to
1639		# explain the tie below that we want to bind to
1640		# a handle class, not scalar. It is not known if
1641		# it is something specific to ActiveState Perl or
1642		# just a Perl quirk.
1643		tie (*ACPIPE, 'Git::activestate_pipe', $cmd, @args);
1644		$fh = *ACPIPE;
1645
1646	} else {
1647		my $pid = open($fh, $direction);
1648		if (not defined $pid) {
1649			throw Error::Simple("open failed: $!");
1650		} elsif ($pid == 0) {
1651			if ($opts{STDERR}) {
1652				open (STDERR, '>&', $opts{STDERR})
1653					or die "dup failed: $!";
1654			} elsif (defined $opts{STDERR}) {
1655				open (STDERR, '>', '/dev/null')
1656					or die "opening /dev/null failed: $!";
1657			}
1658			_cmd_exec($self, $cmd, @args);
1659		}
1660	}
1661	return wantarray ? ($fh, join(' ', $cmd, @args)) : $fh;
1662}
1663
1664# When already in the subprocess, set up the appropriate state
1665# for the given repository and execute the git command.
1666sub _cmd_exec {
1667	my ($self, @args) = @_;
1668	_setup_git_cmd_env($self);
1669	_execv_git_cmd(@args);
1670	die qq[exec "@args" failed: $!];
1671}
1672
1673# set up the appropriate state for git command
1674sub _setup_git_cmd_env {
1675	my $self = shift;
1676	if ($self) {
1677		$self->repo_path() and $ENV{'GIT_DIR'} = $self->repo_path();
1678		$self->repo_path() and $self->wc_path()
1679			and $ENV{'GIT_WORK_TREE'} = $self->wc_path();
1680		$self->wc_path() and chdir($self->wc_path());
1681		$self->wc_subdir() and chdir($self->wc_subdir());
1682	}
1683}
1684
1685# Execute the given Git command ($_[0]) with arguments ($_[1..])
1686# by searching for it at proper places.
1687sub _execv_git_cmd { exec('git', @_); }
1688
1689# Close pipe to a subprocess.
1690sub _cmd_close {
1691	my $ctx = shift @_;
1692	foreach my $fh (@_) {
1693		if (close $fh) {
1694			# nop
1695		} elsif ($!) {
1696			# It's just close, no point in fatalities
1697			carp "error closing pipe: $!";
1698		} elsif ($? >> 8) {
1699			# The caller should pepper this.
1700			throw Git::Error::Command($ctx, $? >> 8);
1701		}
1702		# else we might e.g. closed a live stream; the command
1703		# dying of SIGPIPE would drive us here.
1704	}
1705}
1706
1707
1708sub DESTROY {
1709	my ($self) = @_;
1710	$self->_close_hash_and_insert_object();
1711	$self->_close_cat_blob();
1712}
1713
1714
1715# Pipe implementation for ActiveState Perl.
1716
1717package Git::activestate_pipe;
1718
1719sub TIEHANDLE {
1720	my ($class, @params) = @_;
1721	# FIXME: This is probably horrible idea and the thing will explode
1722	# at the moment you give it arguments that require some quoting,
1723	# but I have no ActiveState clue... --pasky
1724	# Let's just hope ActiveState Perl does at least the quoting
1725	# correctly.
1726	my @data = qx{git @params};
1727	bless { i => 0, data => \@data }, $class;
1728}
1729
1730sub READLINE {
1731	my $self = shift;
1732	if ($self->{i} >= scalar @{$self->{data}}) {
1733		return undef;
1734	}
1735	my $i = $self->{i};
1736	if (wantarray) {
1737		$self->{i} = $#{$self->{'data'}} + 1;
1738		return splice(@{$self->{'data'}}, $i);
1739	}
1740	$self->{i} = $i + 1;
1741	return $self->{'data'}->[ $i ];
1742}
1743
1744sub CLOSE {
1745	my $self = shift;
1746	delete $self->{data};
1747	delete $self->{i};
1748}
1749
1750sub EOF {
1751	my $self = shift;
1752	return ($self->{i} >= scalar @{$self->{data}});
1753}
1754
1755
17561; # Famous last words
1757