perldoc -q timeout
Found in /usr/share/perl/5.8/pod/perlfaq8.pod
       How do I timeout a slow event?

       Use the alarm() function, probably in conjunction with a
       signal handler, as documented in "Signals"
       in perlipc and the section on ``Signals'' in the Camel.
       You may instead use the more flexible Sys::AlarmCall  module available from CPAN.

       The alarm() function is not implemented on all versions of Windows.  
        Check the documentation for your specific version of Perl.