This is expected behaviour. If you ask for something, Perl waits until it gets it. Your alternative is to pass arguments to the script, like the name of a file to open. If the file is empty, then you could exit cleanly.

UPDATE:
Actually, you _could_ use a time out with $SIG{ALRM}:

$SIG{ALRM} = sub { die 'STDIN' };

eval {
   alarm(1);
   print while <>;
   alarm(0);
};

print "no STDIN\n" if $@ =~ /STDIN/;
[download]

You cannot get finer grained than one second with this way, but you can with select.

Or .... just use wog's much more elegant solution. wog++

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)