git/git-difftool.perl
Alex Riesen 677fbff88f Explain seemingly pointless use of system in difftool
Portability reasons.

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-04-24 01:20:35 -07:00

93 lines
2.0 KiB
Perl
Executable File

#!/usr/bin/env perl
# Copyright (c) 2009 David Aguilar
#
# This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
# git-difftool--helper script.
#
# This script exports GIT_EXTERNAL_DIFF and GIT_PAGER for use by git.
# GIT_DIFFTOOL_NO_PROMPT, GIT_DIFFTOOL_PROMPT, and GIT_DIFF_TOOL
# are exported for use by git-difftool--helper.
#
# Any arguments that are unknown to this script are forwarded to 'git diff'.
use strict;
use warnings;
use Cwd qw(abs_path);
use File::Basename qw(dirname);
my $DIR = abs_path(dirname($0));
sub usage
{
print << 'USAGE';
usage: git difftool [--tool=<tool>] [-y|--no-prompt] ["git diff" options]
USAGE
exit 1;
}
sub setup_environment
{
$ENV{PATH} = "$DIR:$ENV{PATH}";
$ENV{GIT_PAGER} = '';
$ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
}
sub exe
{
my $exe = shift;
if ($^O eq 'MSWin32' || $^O eq 'msys') {
return "$exe.exe";
}
return $exe;
}
sub generate_command
{
my @command = (exe('git'), 'diff');
my $skip_next = 0;
my $idx = -1;
for my $arg (@ARGV) {
$idx++;
if ($skip_next) {
$skip_next = 0;
next;
}
if ($arg eq '-t' || $arg eq '--tool') {
usage() if $#ARGV <= $idx;
$ENV{GIT_DIFF_TOOL} = $ARGV[$idx + 1];
$skip_next = 1;
next;
}
if ($arg =~ /^--tool=/) {
$ENV{GIT_DIFF_TOOL} = substr($arg, 7);
next;
}
if ($arg eq '-y' || $arg eq '--no-prompt') {
$ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
delete $ENV{GIT_DIFFTOOL_PROMPT};
next;
}
if ($arg eq '--prompt') {
$ENV{GIT_DIFFTOOL_PROMPT} = 'true';
delete $ENV{GIT_DIFFTOOL_NO_PROMPT};
next;
}
if ($arg eq '-h' || $arg eq '--help') {
usage();
}
push @command, $arg;
}
return @command
}
setup_environment();
# ActiveState Perl for Win32 does not implement POSIX semantics of
# exec* system call. It just spawns the given executable and finishes
# the starting program, exiting with code 0.
# system will at least catch the errors returned by git diff,
# allowing the caller of git difftool better handling of failures.
my $rc = system(generate_command());
exit($rc | ($rc >> 8));