# setup an ALRM handler
my $timed_out = 0;
local $SIG{ALRM} = sub { die "Timed out!" };

# run some code for 10 seconds max
eval {
  alarm 10; # let it run 10 seconds
  eval($code);
  die $@ if $@;
};

# figure out if it got an alarm
warn "Alarm rang!" if $@ and $@ =~ /Timed out!/;