Simple script for using git with alternate ssh keys

gitssh.pl

#!/usr/bin/perl
# This script makes dealing with alternate SSH keys. Rather than
# doing something retarded like mangling your git or ssh settings
# for automated tasks, you can simply use this script..
# It will create a temporary executable shell script (templated below)
# and delete it when it's done.
#
# It requires the GITREPO_KEYFILE environment variable to be set to the
# path of your ssh private key.
# Otherwise, this script will blindly pass arguments to git(1)

use strict;
use warnings;
use Cwd qw(getcwd);
use File::Temp qw(tempfile);

my $kfile = $ENV{GITREPO_KEYFILE} or 
    die "GITREPO_KEYFILE env must be set";


my $fstuff = <<"EOF";
#!/bin/sh
exec ssh -i $kfile \$\@
EOF

my ($fh,$fname) = tempfile(DIR => getcwd(), CLEANUP => 1);

print $fh $fstuff;
close($fh);
chmod(0700, $fname) or die "chmod $fname: $!";

$ENV{GIT_SSH}=$fname;
# use system instead of exec, so that the file gets cleaned up on exit
my $rv = system('git', @ARGV);
unlink($fname);
exit($rv);