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
  19 require Git;
  20
  21 my $DIR = abs_path(dirname($0));
  22
  23
  24 sub usage
  25 {
  26         print << 'USAGE';
  27 usage: git difftool [-t|--tool=<tool>] [-x|--extcmd=<cmd>]
  28                     [-y|--no-prompt]   [-g|--gui]
  29                     ['git diff' options]
  30 USAGE
  31         exit 1;
  32 }
  33
  34 sub setup_environment
  35 {
  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 sub generate_command
  51 {
  52         my @command = (exe('git'), 'diff');
  53         my $skip_next = 0;
  54         my $idx = -1;
  55         for my $arg (@ARGV) {
  56                 $idx++;
  57                 if ($skip_next) {
  58                         $skip_next = 0;
  59                         next;
  60                 }
  61                 if ($arg eq '-t' || $arg eq '--tool') {
  62                         usage() if $#ARGV <= $idx;
  63                         $ENV{GIT_DIFF_TOOL} = $ARGV[$idx + 1];
  64                         $skip_next = 1;
  65                         next;
  66                 }
  67                 if ($arg =~ /^--tool=/) {
  68                         $ENV{GIT_DIFF_TOOL} = substr($arg, 7);
  69                         next;
  70                 }
  71                 if ($arg eq '-x' || $arg eq '--extcmd') {
  72                         usage() if $#ARGV <= $idx;
  73                         $ENV{GIT_DIFFTOOL_EXTCMD} = $ARGV[$idx + 1];
  74                         $skip_next = 1;
  75                         next;
  76                 }
  77                 if ($arg =~ /^--extcmd=/) {
  78                         $ENV{GIT_DIFFTOOL_EXTCMD} = substr($arg, 9);
  79                         next;
  80                 }
  81                 if ($arg eq '-g' || $arg eq '--gui') {
  82                         eval {
  83                                 my $tool = Git::command_oneline('config',
  84                                                                 'diff.guitool');
  85                                 if (length($tool)) {
  86                                         $ENV{GIT_DIFF_TOOL} = $tool;
  87                                 }
  88                         };
  89                         next;
  90                 }
  91                 if ($arg eq '-y' || $arg eq '--no-prompt') {
  92                         $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
  93                         delete $ENV{GIT_DIFFTOOL_PROMPT};
  94                         next;
  95                 }
  96                 if ($arg eq '--prompt') {
  97                         $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
  98                         delete $ENV{GIT_DIFFTOOL_NO_PROMPT};
  99                         next;
 100                 }
 101                 if ($arg eq '-h' || $arg eq '--help') {
 102                         usage();
 103                 }
 104                 push @command, $arg;
 105         }
 106         return @command
 107 }
 108
 109 setup_environment();
 110
 111 # ActiveState Perl for Win32 does not implement POSIX semantics of
 112 # exec* system call. It just spawns the given executable and finishes
 113 # the starting program, exiting with code 0.
 114 # system will at least catch the errors returned by git diff,
 115 # allowing the caller of git difftool better handling of failures.
 116 my $rc = system(generate_command());
 117 exit($rc | ($rc >> 8));