am: Use cat instead of echo to avoid DOS line-endings (fixes t4150)
[git/dscho.git] / git-difftool.perl
blobae1e0525d89181f8adbe288b62e107b8dadb8ca1
1 #!/usr/bin/perl
2 # Copyright (c) 2009, 2010 David Aguilar
3 # Copyright (c) 2012 Tim Henigan
5 # This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
6 # git-difftool--helper script.
8 # This script exports GIT_EXTERNAL_DIFF and GIT_PAGER for use by git.
9 # The GIT_DIFF* variables are exported for use by git-difftool--helper.
11 # Any arguments that are unknown to this script are forwarded to 'git diff'.
13 use 5.008;
14 use strict;
15 use warnings;
16 use File::Basename qw(dirname);
17 use File::Copy;
18 use File::Find;
19 use File::stat;
20 use File::Path qw(mkpath);
21 use File::Temp qw(tempdir);
22 use Getopt::Long qw(:config pass_through);
23 use Git;
25 my @tools;
26 my @working_tree;
27 my $rc;
28 my $repo = Git->repository();
29 my $repo_path = $repo->repo_path();
31 sub usage
33 my $exitcode = shift;
34 print << 'USAGE';
35 usage: git difftool [-t|--tool=<tool>] [--tool-help]
36 [-x|--extcmd=<cmd>]
37 [-g|--gui] [--no-gui]
38 [--prompt] [-y|--no-prompt]
39 [-d|--dir-diff]
40 ['git diff' options]
41 USAGE
42 exit($exitcode);
45 sub find_worktree
47 # Git->repository->wc_path() does not honor changes to the working
48 # tree location made by $ENV{GIT_WORK_TREE} or the 'core.worktree'
49 # config variable.
50 my $worktree;
51 my $env_worktree = $ENV{GIT_WORK_TREE};
52 my $core_worktree = Git::config('core.worktree');
54 if (defined($env_worktree) and (length($env_worktree) > 0)) {
55 $worktree = $env_worktree;
56 } elsif (defined($core_worktree) and (length($core_worktree) > 0)) {
57 $worktree = $core_worktree;
58 } else {
59 $worktree = $repo->wc_path();
62 return $worktree;
65 my $workdir = find_worktree();
67 sub filter_tool_scripts
69 if (-d $_) {
70 if ($_ ne ".") {
71 # Ignore files in subdirectories
72 $File::Find::prune = 1;
74 } else {
75 if ((-f $_) && ($_ ne "defaults")) {
76 push(@tools, $_);
81 sub print_tool_help
83 my ($cmd, @found, @notfound);
84 my $gitpath = Git::exec_path();
86 find(\&filter_tool_scripts, "$gitpath/mergetools");
88 foreach my $tool (@tools) {
89 $cmd = "TOOL_MODE=diff";
90 $cmd .= ' && . "$(git --exec-path)/git-mergetool--lib"';
91 $cmd .= " && get_merge_tool_path $tool >/dev/null 2>&1";
92 $cmd .= " && can_diff >/dev/null 2>&1";
93 if (system('sh', '-c', $cmd) == 0) {
94 push(@found, $tool);
95 } else {
96 push(@notfound, $tool);
100 print "'git difftool --tool=<tool>' may be set to one of the following:\n";
101 print "\t$_\n" for (sort(@found));
103 print "\nThe following tools are valid, but not currently available:\n";
104 print "\t$_\n" for (sort(@notfound));
106 print "\nNOTE: Some of the tools listed above only work in a windowed\n";
107 print "environment. If run in a terminal-only session, they will fail.\n";
109 exit(0);
112 sub setup_dir_diff
114 # Run the diff; exit immediately if no diff found
115 # 'Repository' and 'WorkingCopy' must be explicitly set to insure that
116 # if $GIT_DIR and $GIT_WORK_TREE are set in ENV, they are actually used
117 # by Git->repository->command*.
118 my $diffrepo = Git->repository(Repository => $repo_path, WorkingCopy => $workdir);
119 my $diffrtn = $diffrepo->command_oneline('diff', '--raw', '--no-abbrev', '-z', @ARGV);
120 exit(0) if (length($diffrtn) == 0);
122 # Setup temp directories
123 my $tmpdir = tempdir('git-diffall.XXXXX', CLEANUP => 1, TMPDIR => 1);
124 my $ldir = "$tmpdir/left";
125 my $rdir = "$tmpdir/right";
126 mkpath($ldir) or die $!;
127 mkpath($rdir) or die $!;
129 # Build index info for left and right sides of the diff
130 my $submodule_mode = '160000';
131 my $symlink_mode = '120000';
132 my $null_mode = '0' x 6;
133 my $null_sha1 = '0' x 40;
134 my $lindex = '';
135 my $rindex = '';
136 my %submodule;
137 my %symlink;
138 my @rawdiff = split('\0', $diffrtn);
140 my $i = 0;
141 while ($i < $#rawdiff) {
142 if ($rawdiff[$i] =~ /^::/) {
143 print "Combined diff formats ('-c' and '--cc') are not supported in directory diff mode.\n";
144 exit(1);
147 my ($lmode, $rmode, $lsha1, $rsha1, $status) = split(' ', substr($rawdiff[$i], 1));
148 my $src_path = $rawdiff[$i + 1];
149 my $dst_path;
151 if ($status =~ /^[CR]/) {
152 $dst_path = $rawdiff[$i + 2];
153 $i += 3;
154 } else {
155 $dst_path = $src_path;
156 $i += 2;
159 if (($lmode eq $submodule_mode) or ($rmode eq $submodule_mode)) {
160 $submodule{$src_path}{left} = $lsha1;
161 if ($lsha1 ne $rsha1) {
162 $submodule{$dst_path}{right} = $rsha1;
163 } else {
164 $submodule{$dst_path}{right} = "$rsha1-dirty";
166 next;
169 if ($lmode eq $symlink_mode) {
170 $symlink{$src_path}{left} = $diffrepo->command_oneline('show', "$lsha1");
173 if ($rmode eq $symlink_mode) {
174 $symlink{$dst_path}{right} = $diffrepo->command_oneline('show', "$rsha1");
177 if (($lmode ne $null_mode) and ($status !~ /^C/)) {
178 $lindex .= "$lmode $lsha1\t$src_path\0";
181 if ($rmode ne $null_mode) {
182 if ($rsha1 ne $null_sha1) {
183 $rindex .= "$rmode $rsha1\t$dst_path\0";
184 } else {
185 push(@working_tree, $dst_path);
190 # If $GIT_DIR is not set prior to calling 'git update-index' and
191 # 'git checkout-index', then those commands will fail if difftool
192 # is called from a directory other than the repo root.
193 my $must_unset_git_dir = 0;
194 if (not defined($ENV{GIT_DIR})) {
195 $must_unset_git_dir = 1;
196 $ENV{GIT_DIR} = $repo_path;
199 # Populate the left and right directories based on each index file
200 my ($inpipe, $ctx);
201 $ENV{GIT_INDEX_FILE} = "$tmpdir/lindex";
202 ($inpipe, $ctx) = $repo->command_input_pipe(qw/update-index -z --index-info/);
203 print($inpipe $lindex);
204 $repo->command_close_pipe($inpipe, $ctx);
205 $rc = system('git', 'checkout-index', '--all', "--prefix=$ldir/");
206 exit($rc | ($rc >> 8)) if ($rc != 0);
208 $ENV{GIT_INDEX_FILE} = "$tmpdir/rindex";
209 ($inpipe, $ctx) = $repo->command_input_pipe(qw/update-index -z --index-info/);
210 print($inpipe $rindex);
211 $repo->command_close_pipe($inpipe, $ctx);
212 $rc = system('git', 'checkout-index', '--all', "--prefix=$rdir/");
213 exit($rc | ($rc >> 8)) if ($rc != 0);
215 # If $GIT_DIR was explicitly set just for the update/checkout
216 # commands, then it should be unset before continuing.
217 delete($ENV{GIT_DIR}) if ($must_unset_git_dir);
218 delete($ENV{GIT_INDEX_FILE});
220 # Changes in the working tree need special treatment since they are
221 # not part of the index
222 for my $file (@working_tree) {
223 my $dir = dirname($file);
224 unless (-d "$rdir/$dir") {
225 mkpath("$rdir/$dir") or die $!;
227 copy("$workdir/$file", "$rdir/$file") or die $!;
228 chmod(stat("$workdir/$file")->mode, "$rdir/$file") or die $!;
231 # Changes to submodules require special treatment. This loop writes a
232 # temporary file to both the left and right directories to show the
233 # change in the recorded SHA1 for the submodule.
234 for my $path (keys %submodule) {
235 if (defined($submodule{$path}{left})) {
236 write_to_file("$ldir/$path", "Subproject commit $submodule{$path}{left}");
238 if (defined($submodule{$path}{right})) {
239 write_to_file("$rdir/$path", "Subproject commit $submodule{$path}{right}");
243 # Symbolic links require special treatment. The standard "git diff"
244 # shows only the link itself, not the contents of the link target.
245 # This loop replicates that behavior.
246 for my $path (keys %symlink) {
247 if (defined($symlink{$path}{left})) {
248 write_to_file("$ldir/$path", $symlink{$path}{left});
250 if (defined($symlink{$path}{right})) {
251 write_to_file("$rdir/$path", $symlink{$path}{right});
255 return ($ldir, $rdir);
258 sub write_to_file
260 my $path = shift;
261 my $value = shift;
263 # Make sure the path to the file exists
264 my $dir = dirname($path);
265 unless (-d "$dir") {
266 mkpath("$dir") or die $!;
269 # If the file already exists in that location, delete it. This
270 # is required in the case of symbolic links.
271 unlink("$path");
273 open(my $fh, '>', "$path") or die $!;
274 print($fh $value);
275 close($fh);
278 # parse command-line options. all unrecognized options and arguments
279 # are passed through to the 'git diff' command.
280 my ($difftool_cmd, $dirdiff, $extcmd, $gui, $help, $prompt, $tool_help);
281 GetOptions('g|gui!' => \$gui,
282 'd|dir-diff' => \$dirdiff,
283 'h' => \$help,
284 'prompt!' => \$prompt,
285 'y' => sub { $prompt = 0; },
286 't|tool:s' => \$difftool_cmd,
287 'tool-help' => \$tool_help,
288 'x|extcmd:s' => \$extcmd);
290 if (defined($help)) {
291 usage(0);
293 if (defined($tool_help)) {
294 print_tool_help();
296 if (defined($difftool_cmd)) {
297 if (length($difftool_cmd) > 0) {
298 $ENV{GIT_DIFF_TOOL} = $difftool_cmd;
299 } else {
300 print "No <tool> given for --tool=<tool>\n";
301 usage(1);
304 if (defined($extcmd)) {
305 if (length($extcmd) > 0) {
306 $ENV{GIT_DIFFTOOL_EXTCMD} = $extcmd;
307 } else {
308 print "No <cmd> given for --extcmd=<cmd>\n";
309 usage(1);
312 if ($gui) {
313 my $guitool = '';
314 $guitool = Git::config('diff.guitool');
315 if (length($guitool) > 0) {
316 $ENV{GIT_DIFF_TOOL} = $guitool;
320 # In directory diff mode, 'git-difftool--helper' is called once
321 # to compare the a/b directories. In file diff mode, 'git diff'
322 # will invoke a separate instance of 'git-difftool--helper' for
323 # each file that changed.
324 if (defined($dirdiff)) {
325 my ($a, $b) = setup_dir_diff();
326 if (defined($extcmd)) {
327 $rc = system($extcmd, $a, $b);
328 } else {
329 $ENV{GIT_DIFFTOOL_DIRDIFF} = 'true';
330 $rc = system('git', 'difftool--helper', $a, $b);
333 exit($rc | ($rc >> 8)) if ($rc != 0);
335 # If the diff including working copy files and those
336 # files were modified during the diff, then the changes
337 # should be copied back to the working tree
338 for my $file (@working_tree) {
339 copy("$b/$file", "$workdir/$file") or die $!;
340 chmod(stat("$b/$file")->mode, "$workdir/$file") or die $!;
342 } else {
343 if (defined($prompt)) {
344 if ($prompt) {
345 $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
346 } else {
347 $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
351 $ENV{GIT_PAGER} = '';
352 $ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
354 # ActiveState Perl for Win32 does not implement POSIX semantics of
355 # exec* system call. It just spawns the given executable and finishes
356 # the starting program, exiting with code 0.
357 # system will at least catch the errors returned by git diff,
358 # allowing the caller of git difftool better handling of failures.
359 my $rc = system('git', 'diff', @ARGV);
360 exit($rc | ($rc >> 8));