#!/usr/bin/perl
##########################################################################
# pandora_exec
#
# Executes the given command and prints its output to stdout. If the
# execution times out or the command does not exist nothing is printed
# to stdout.
#
# Usage: pandora_exec <timeout in seconds> <command> [arguments]
##########################################################################
# Copyright (c) 2008 Ramon Novoa, rnovoa@gmail.com
#           (c) 2008 Artica Soluciones Tecnologicas S.L
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; version 2.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
##########################################################################

use strict;
use warnings;

# Check command line parameters 
if ($#ARGV < 1) {
	exit 1;	
}

my @opts = @ARGV;
my $timeout = shift(@opts);
my $command = quotemeta(shift(@opts));
my $arguments = join(' ', @opts);
my $output = '';

# Check that the command exists
if (system("$command >/dev/null 2>&1") == 32512) {
	exit 2;
}

# Execute the command
eval {
	local $SIG{ALRM} = sub { die "alarm\n" };
	alarm $timeout;

	$output = `$command $arguments`;
	alarm 0;
};

# Timeout
if ($@ eq "alarm\n") {
	exit 3;
}

print $output;

exit 0;