#!/usr/bin/env perl

use strict;
use warnings;

$SIG{ALRM} = sub {
    print( "Alarm triggered, making system call...\n" );
    unlink('/doesnt/exist');  # this will definitely fail
};
alarm( 2 );

my $retval = system('sleep 4');

if( $retval == -1 ) {
    print( "system() retval = $retval; " . '$?' . " = $?; " . '$!' . " = $!\n" );
}
elsif( $retval == 0 ) {
    print( "system() returned 0\n" );
}
else {
    print( "system() return $retval\n" );
}

##</code><code>##

test$ ./test.pl 
Alarm triggered, making system call...
system() retval = -1; $? = -1; $! = No such file or directory

##</code><code>##

System 1:
$ perl -v
This is perl, v5.8.8 built for i386-linux-thread-multi

libc=/lib/libc-2.5.so

$ uname -a
Linux hostname.removed 2.6.18-8.1.1.el5 #1 SMP Mon Feb 26 20:38:02 EST 2007 i686 i686 i386 GNU/Linux


System 2:
test$ perl -v
This is perl, v5.8.6 built for i686-linux-64int

libc=/lib/libc-2.3.2.so

test$ uname -a
Linux hostname.removed 2.6.9-55.0.6.ELsmp #1 SMP Tue Sep 4 21:36:00 EDT 2007 i686 unknown