It is true that Activestate perls have no capability and if
you absolutly must use Activestate then alarm is no
supported. However on the perl that comes with the
cygwin system (running Win98) I ran your code and
other basic uses of an alarm with exactly the same
behaviour as on my linux system.
in reply to cross-platform timeout on user input
In case you don't know it, cygwin runs on most windows
platforms and has a pile of modular components including
the a good selection of those utilities missing from a non unix
system: perl, grep, bash, gcc, tar, wget, and many more.
Cygwin also allows you to compile many perl modules
without depending on ppm like Activestate, though in using
it some modules avalible in the ppm archives are very
difficult/impossible to get to work.
If you are going to be installing perl on many systems
anyway then cygwin may be a good option to explore.