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