Merge branch 'maint'
[git] / git-difftool.perl
1 #!/usr/bin/env perl
2 # Copyright (c) 2009, 2010 David Aguilar
3 #
4 # This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
5 # git-difftool--helper script.
6 #
7 # This script exports GIT_EXTERNAL_DIFF and GIT_PAGER for use by git.
8 # GIT_DIFFTOOL_NO_PROMPT, GIT_DIFFTOOL_PROMPT, and GIT_DIFF_TOOL
9 # are exported for use by git-difftool--helper.
10 #
11 # Any arguments that are unknown to this script are forwarded to 'git diff'.
12
13 use strict;
14 use warnings;
15 use Cwd qw(abs_path);
16 use File::Basename qw(dirname);
17
18 require Git;
19
20 my $DIR = abs_path(dirname($0));
21
22
23 sub usage
24 {
25         print << 'USAGE';
26 usage: git difftool [-t|--tool=<tool>] [-x|--extcmd=<cmd>]
27                     [-y|--no-prompt]   [-g|--gui]
28                     ['git diff' options]
29 USAGE
30         exit 1;
31 }
32
33 sub setup_environment
34 {
35         $ENV{PATH} = "$DIR:$ENV{PATH}";
36         $ENV{GIT_PAGER} = '';
37         $ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
38 }
39
40 sub exe
41 {
42         my $exe = shift;
43         if ($^O eq 'MSWin32' || $^O eq 'msys') {
44                 return "$exe.exe";
45         }
46         return $exe;
47 }
48
49 sub generate_command
50 {
51         my @command = (exe('git'), 'diff');
52         my $skip_next = 0;
53         my $idx = -1;
54         for my $arg (@ARGV) {
55                 $idx++;
56                 if ($skip_next) {
57                         $skip_next = 0;
58                         next;
59                 }
60                 if ($arg eq '-t' || $arg eq '--tool') {
61                         usage() if $#ARGV <= $idx;
62                         $ENV{GIT_DIFF_TOOL} = $ARGV[$idx + 1];
63                         $skip_next = 1;
64                         next;
65                 }
66                 if ($arg =~ /^--tool=/) {
67                         $ENV{GIT_DIFF_TOOL} = substr($arg, 7);
68                         next;
69                 }
70                 if ($arg eq '-x' || $arg eq '--extcmd') {
71                         usage() if $#ARGV <= $idx;
72                         $ENV{GIT_DIFFTOOL_EXTCMD} = $ARGV[$idx + 1];
73                         $skip_next = 1;
74                         next;
75                 }
76                 if ($arg =~ /^--extcmd=/) {
77                         $ENV{GIT_DIFFTOOL_EXTCMD} = substr($arg, 9);
78                         next;
79                 }
80                 if ($arg eq '-g' || $arg eq '--gui') {
81                         eval {
82                                 my $tool = Git::command_oneline('config',
83                                                                 'diff.guitool');
84                                 if (length($tool)) {
85                                         $ENV{GIT_DIFF_TOOL} = $tool;
86                                 }
87                         };
88                         next;
89                 }
90                 if ($arg eq '-y' || $arg eq '--no-prompt') {
91                         $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
92                         delete $ENV{GIT_DIFFTOOL_PROMPT};
93                         next;
94                 }
95                 if ($arg eq '--prompt') {
96                         $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
97                         delete $ENV{GIT_DIFFTOOL_NO_PROMPT};
98                         next;
99                 }
100                 if ($arg eq '-h' || $arg eq '--help') {
101                         usage();
102                 }
103                 push @command, $arg;
104         }
105         return @command
106 }
107
108 setup_environment();
109
110 # ActiveState Perl for Win32 does not implement POSIX semantics of
111 # exec* system call. It just spawns the given executable and finishes
112 # the starting program, exiting with code 0.
113 # system will at least catch the errors returned by git diff,
114 # allowing the caller of git difftool better handling of failures.
115 my $rc = system(generate_command());
116 exit($rc | ($rc >> 8));