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 Getopt::Long qw(:config pass_through);
  17 use Git;
  18
  19 sub usage
  20 {
  21         my $exitcode = shift;
  22         print << 'USAGE';
  23 usage: git difftool [-t|--tool=<tool>]
  24                     [-x|--extcmd=<cmd>]
  25                     [-g|--gui] [--no-gui]
  26                     [--prompt] [-y|--no-prompt]
  27                     ['git diff' options]
  28 USAGE
  29         exit($exitcode);
  30 }
  31
  32 sub setup_environment
  33 {
  34         $ENV{GIT_PAGER} = '';
  35         $ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
  36 }
  37
  38 # parse command-line options. all unrecognized options and arguments
  39 # are passed through to the 'git diff' command.
  40 my ($difftool_cmd, $extcmd, $gui, $help, $prompt);
  41 GetOptions('g|gui!' => \$gui,
  42         'h' => \$help,
  43         'prompt!' => \$prompt,
  44         'y' => sub { $prompt = 0; },
  45         't|tool:s' => \$difftool_cmd,
  46         'x|extcmd:s' => \$extcmd);
  47
  48 if (defined($help)) {
  49         usage(0);
  50 }
  51 if (defined($difftool_cmd)) {
  52         if (length($difftool_cmd) > 0) {
  53                 $ENV{GIT_DIFF_TOOL} = $difftool_cmd;
  54         } else {
  55                 print "No <tool> given for --tool=<tool>\n";
  56                 usage(1);
  57         }
  58 }
  59 if (defined($extcmd)) {
  60         if (length($extcmd) > 0) {
  61                 $ENV{GIT_DIFFTOOL_EXTCMD} = $extcmd;
  62         } else {
  63                 print "No <cmd> given for --extcmd=<cmd>\n";
  64                 usage(1);
  65         }
  66 }
  67 if ($gui) {
  68         my $guitool = "";
  69         $guitool = Git::config('diff.guitool');
  70         if (length($guitool) > 0) {
  71                 $ENV{GIT_DIFF_TOOL} = $guitool;
  72         }
  73 }
  74 if (defined($prompt)) {
  75         if ($prompt) {
  76                 $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
  77         } else {
  78                 $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
  79         }
  80 }
  81
  82 setup_environment();
  83 my @command = ('git', 'diff', @ARGV);
  84
  85 # ActiveState Perl for Win32 does not implement POSIX semantics of
  86 # exec* system call. It just spawns the given executable and finishes
  87 # the starting program, exiting with code 0.
  88 # system will at least catch the errors returned by git diff,
  89 # allowing the caller of git difftool better handling of failures.
  90 my $rc = system(@command);
  91 exit($rc | ($rc >> 8));