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