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 5.008;
  14 use strict;
  15 use warnings;
  16 use Cwd qw(abs_path);
  17 use File::Basename qw(dirname);
  18 use Getopt::Long qw(:config pass_through);
  19 use Git;
  20
  21 sub usage
  22 {
  23         print << 'USAGE';
  24 usage: git difftool [-t|--tool=<tool>]
  25                     [-x|--extcmd=<cmd>] [-g|--gui]
  26                     [--prompt] [-y|--no-prompt]
  27                     ['git diff' options]
  28 USAGE
  29         exit 1;
  30 }
  31
  32 sub setup_environment
  33 {
  34         my $DIR = abs_path(dirname($0));
  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 $exe;
  47 }
  48
  49 # parse command-line options. all unrecognized options and arguments
  50 # are passed through to the 'git diff' command.
  51 my ($difftool_cmd, $extcmd, $gui, $help, $prompt);
  52 GetOptions('g|gui' => \$gui,
  53         'h' => \$help,
  54         'prompt!' => \$prompt,
  55         'y' => sub { $prompt = 0; },
  56         't|tool:s' => \$difftool_cmd,
  57         'x|extcmd:s' => \$extcmd);
  58
  59 if (defined($help)) {
  60         usage();
  61 }
  62 if (defined($difftool_cmd)) {
  63         if (length($difftool_cmd) > 0) {
  64                 $ENV{GIT_DIFF_TOOL} = $difftool_cmd;
  65         } else {
  66                 print "No <tool> given for --tool=<tool>\n";
  67                 usage();
  68         }
  69 }
  70 if (defined($extcmd)) {
  71         if (length($extcmd) > 0) {
  72                 $ENV{GIT_DIFFTOOL_EXTCMD} = $extcmd;
  73         } else {
  74                 print "No <cmd> given for --extcmd=<cmd>\n";
  75                 usage();
  76         }
  77 }
  78 if (defined($gui)) {
  79         my $guitool = "";
  80         $guitool = Git::config('diff.guitool');
  81         if (length($guitool) > 0) {
  82                 $ENV{GIT_DIFF_TOOL} = $guitool;
  83         }
  84 }
  85 if (defined($prompt)) {
  86         if ($prompt) {
  87                 $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
  88         } else {
  89                 $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
  90         }
  91 }
  92
  93 setup_environment();
  94 my @command = (exe('git'), 'diff', @ARGV);
  95
  96 # ActiveState Perl for Win32 does not implement POSIX semantics of
  97 # exec* system call. It just spawns the given executable and finishes
  98 # the starting program, exiting with code 0.
  99 # system will at least catch the errors returned by git diff,
 100 # allowing the caller of git difftool better handling of failures.
 101 my $rc = system(@command);
 102 exit($rc | ($rc >> 8));