view release on metacpan or  search on metacpan

lib/POD2/RU/perlfunc.pod  view on Meta::CPAN

    };
    die $@ unless $@ eq "Alarm!\n";

You probably cannot mix C<alarm> and C<sleep> calls, because C<sleep>
is often implemented using C<alarm>.

On some older systems, it may sleep up to a full second less than what
you requested, depending on how it counts seconds.  Most modern systems
always sleep the full amount.  They may appear to sleep longer than that,
however, because your process might not be scheduled right away in a
busy multitasking system.

For delays of finer granularity than one second, the Time::HiRes module
(from CPAN, and starting from Perl 5.8 part of the standard
distribution) provides usleep().  You may also use Perl's four-argument
version of select() leaving the first three arguments undefined, or you
might be able to use the C<syscall> interface to access setitimer(2) if
your system supports it.  See L<perlfaq8> for details.

See also the POSIX module's C<pause> function.