#!/usr/bin/perl -l
use strict;
use warnings;

spawn(5, "/tmp/cmd.pl");

sub spawn
{
    my ($timeout, @cmd) = @_;

    defined( my $child_pid = fork ) or die "fork: $!";

    if ($child_pid)
    {
        # parent
        eval
        {
            local $SIG{ALRM} = sub { timeout($child_pid); };
            alarm $timeout;
            waitpid $child_pid, 0;
            alarm 0;
        };

        if ($@)
        {
            print "oops: $@";
        }
    }
    else
    {
        # child
        exec @cmd or die "exec: $!";
    }
}

sub timeout
{
    my ($pid) = @_;
    kill 'TERM' => $pid;
    waitpid $pid, 0;
    die "reaped $pid\n";
}