Andrew's git - gitweb.git/blob

   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.
   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
  13use strict;
  14use warnings;
  15use Cwd qw(abs_path);
  16use File::Basename qw(dirname);
  17
  18my $DIR = abs_path(dirname($0));
  19
  20
  21sub usage
  22{
  23        print << 'USAGE';
  24usage: git difftool [--tool=<tool>] [-y|--no-prompt] ["git diff" options]
  25USAGE
  26        exit 1;
  27}
  28
  29sub setup_environment
  30{
  31        $ENV{PATH} = "$DIR:$ENV{PATH}";
  32        $ENV{GIT_PAGER} = '';
  33        $ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
  34}
  35
  36sub exe
  37{
  38        my $exe = shift;
  39        if ($^O eq 'MSWin32' || $^O eq 'msys') {
  40                return "$exe.exe";
  41        }
  42        return $exe;
  43}
  44
  45sub generate_command
  46{
  47        my @command = (exe('git'), 'diff');
  48        my $skip_next = 0;
  49        my $idx = -1;
  50        for my $arg (@ARGV) {
  51                $idx++;
  52                if ($skip_next) {
  53                        $skip_next = 0;
  54                        next;
  55                }
  56                if ($arg eq '-t' || $arg eq '--tool') {
  57                        usage() if $#ARGV <= $idx;
  58                        $ENV{GIT_DIFF_TOOL} = $ARGV[$idx + 1];
  59                        $skip_next = 1;
  60                        next;
  61                }
  62                if ($arg =~ /^--tool=/) {
  63                        $ENV{GIT_DIFF_TOOL} = substr($arg, 7);
  64                        next;
  65                }
  66                if ($arg eq '-y' || $arg eq '--no-prompt') {
  67                        $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
  68                        delete $ENV{GIT_DIFFTOOL_PROMPT};
  69                        next;
  70                }
  71                if ($arg eq '--prompt') {
  72                        $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
  73                        delete $ENV{GIT_DIFFTOOL_NO_PROMPT};
  74                        next;
  75                }
  76                if ($arg eq '-h' || $arg eq '--help') {
  77                        usage();
  78                }
  79                push @command, $arg;
  80        }
  81        return @command
  82}
  83
  84setup_environment();
  85
  86# ActiveState Perl for Win32 does not implement POSIX semantics of
  87# exec* system call. It just spawns the given executable and finishes
  88# the starting program, exiting with code 0.
  89# system will at least catch the errors returned by git diff,
  90# allowing the caller of git difftool better handling of failures.
  91my $rc = system(generate_command());
  92exit($rc | ($rc >> 8));