#!/usr/bin/perl
################################################################################
# pandora_exec - Execute a command with a time limit.
#
# Copyright (c) 2008-2023 Artica PFMS 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;
use POSIX qw(WEXITSTATUS WIFEXITED);

# Check command line arguments. 
if ($#ARGV < 1) {
	print("Usage: $0 <timeout in seconds> <command>\n");
	exit 1;	
}

my @opts = @ARGV;
my $timeout = shift(@opts);
my $command = ($0 =~ m/_agent_exec$/) ? # For backward compatibility with pandora_agent.
              join(' ', @opts) :
              join(' ', map { quotemeta($_) } @opts);

# Fork:
# * The child will run the command.
# * The parent will timeout if needed
#   and exit with the appropriate exit status.
my $pid = fork();
if ($pid == 0) {
	setpgrp();
	exec($command);
} else {
	eval {
		local $SIG{ALRM} = sub { kill(9, -$pid); exit 1; };
		alarm $timeout;
		waitpid($pid, 0);
		alarm 0;
		if (WIFEXITED(${^CHILD_ERROR_NATIVE})) {
			exit WEXITSTATUS(${^CHILD_ERROR_NATIVE});
		}
	};
}

exit 1;