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>]
  26                     [-g|--gui] [--no-gui]
  27                     [--prompt] [-y|--no-prompt]
  28                     ['git diff' options]
  29 USAGE
  30         exit 1;
  31 }
  32
  33 sub setup_environment
  34 {
  35         my $DIR = abs_path(dirname($0));
  36         $ENV{PATH} = "$DIR:$ENV{PATH}";
  37         $ENV{GIT_PAGER} = '';
  38         $ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
  39 }
  40
  41 sub exe
  42 {
  43         my $exe = shift;
  44         if ($^O eq 'MSWin32' || $^O eq 'msys') {
  45                 return "$exe.exe";
  46         }
  47         return $exe;
  48 }
  49
  50 # parse command-line options. all unrecognized options and arguments
  51 # are passed through to the 'git diff' command.
  52 my ($difftool_cmd, $extcmd, $gui, $help, $prompt);
  53 GetOptions('g|gui!' => \$gui,
  54         'h' => \$help,
  55         'prompt!' => \$prompt,
  56         'y' => sub { $prompt = 0; },
  57         't|tool:s' => \$difftool_cmd,
  58         'x|extcmd:s' => \$extcmd);
  59
  60 if (defined($help)) {
  61         usage();
  62 }
  63 if (defined($difftool_cmd)) {
  64         if (length($difftool_cmd) > 0) {
  65                 $ENV{GIT_DIFF_TOOL} = $difftool_cmd;
  66         } else {
  67                 print "No <tool> given for --tool=<tool>\n";
  68                 usage();
  69         }
  70 }
  71 if (defined($extcmd)) {
  72         if (length($extcmd) > 0) {
  73                 $ENV{GIT_DIFFTOOL_EXTCMD} = $extcmd;
  74         } else {
  75                 print "No <cmd> given for --extcmd=<cmd>\n";
  76                 usage();
  77         }
  78 }
  79 if ($gui) {
  80         my $guitool = "";
  81         $guitool = Git::config('diff.guitool');
  82         if (length($guitool) > 0) {
  83                 $ENV{GIT_DIFF_TOOL} = $guitool;
  84         }
  85 }
  86 if (defined($prompt)) {
  87         if ($prompt) {
  88                 $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
  89         } else {
  90                 $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
  91         }
  92 }
  93
  94 setup_environment();
  95 my @command = (exe('git'), 'diff', @ARGV);
  96
  97 # ActiveState Perl for Win32 does not implement POSIX semantics of
  98 # exec* system call. It just spawns the given executable and finishes
  99 # the starting program, exiting with code 0.
 100 # system will at least catch the errors returned by git diff,
 101 # allowing the caller of git difftool better handling of failures.
 102 my $rc = system(@command);
 103 exit($rc | ($rc >> 8));