git-difftool.perl

   1 #!/usr/bin/env perl
   2 # Copyright (c) 2009 David Aguilar
   3 #
   4 # This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
   5 # git-difftool-helper script.  This script exports
   6 # GIT_EXTERNAL_DIFF and GIT_PAGER for use by git, and
   7 # GIT_DIFFTOOL_NO_PROMPT and GIT_DIFF_TOOL for use by git-difftool-helper.
   8 # Any arguments that are unknown to this script are forwarded to 'git diff'.
   9
  10 use strict;
  11 use warnings;
  12 use Cwd qw(abs_path);
  13 use File::Basename qw(dirname);
  14
  15 my $DIR = abs_path(dirname($0));
  16
  17
  18 sub usage
  19 {
  20         print << 'USAGE';
  21 usage: git difftool [--tool=<tool>] [--no-prompt] ["git diff" options]
  22 USAGE
  23         exit 1;
  24 }
  25
  26 sub setup_environment
  27 {
  28         $ENV{PATH} = "$DIR:$ENV{PATH}";
  29         $ENV{GIT_PAGER} = '';
  30         $ENV{GIT_EXTERNAL_DIFF} = 'git-difftool-helper';
  31 }
  32
  33 sub exe
  34 {
  35         my $exe = shift;
  36         return defined $ENV{COMSPEC} ? "$exe.exe" : $exe;
  37 }
  38
  39 sub generate_command
  40 {
  41         my @command = (exe('git'), 'diff');
  42         my $skip_next = 0;
  43         my $idx = -1;
  44         for my $arg (@ARGV) {
  45                 $idx++;
  46                 if ($skip_next) {
  47                         $skip_next = 0;
  48                         next;
  49                 }
  50                 if ($arg eq '-t' or $arg eq '--tool') {
  51                         usage() if $#ARGV <= $idx;
  52                         $ENV{GIT_DIFF_TOOL} = $ARGV[$idx + 1];
  53                         $skip_next = 1;
  54                         next;
  55                 }
  56                 if ($arg =~ /^--tool=/) {
  57                         $ENV{GIT_DIFF_TOOL} = substr($arg, 7);
  58                         next;
  59                 }
  60                 if ($arg eq '--no-prompt') {
  61                         $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
  62                         next;
  63                 }
  64                 if ($arg eq '-h' or $arg eq '--help') {
  65                         usage();
  66                 }
  67                 push @command, $arg;
  68         }
  69         return @command
  70 }
  71
  72 setup_environment();
  73 exec(generate_command());