Perlでタイムアウトを設定して外部コマンドを実行する ref: http://qiita.com/memememomo/items/72a10e1bbe04b57f5666

sample.pl

use strict;
use warnings;
use POSIX qw( SIGKILL );

my $TIMEOUT = 10;
my $cmd = "sleep 15";

my $pid = fork();
if (!defined($pid)) { die "failed to fork"; }
if ($pid == 0) {
    exec($cmd);
    exit;
}
elsif ($pid) {
    my $timeout = 0;
    eval {
        local $SIG{ALRM} = sub {
            $timeout = 1;
        };
        alarm($TIMEOUT);
        while(!$timeout) {
            last if waitpid($pid, POSIX::WNOHANG);
            sleep(1);
        }
    };
    if ($@) {
        warn "Error:".$@;
    }
    if ($timeout) {
        kill(SIGKILL, $pid);
        warn "TIMEOUT";
    }
}