Very simply ... sleep!

Something like sleep, perhaps? For more fun, try the 4-argument form of select.

If sleep is interrupted by another signal, your program won't know unless it checks:

my $delay = 5;
$delay -= sleep $delay
    while $delay > 0;
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sleep usage:

while ( not defined $result ) {
    ( $result = try( $something ) ) or sleep 3;
}
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And a select example:

while ( not defined $result ) {
    ( $result = try( $something ) )
        or select undef, undef, undef, 3000;
}
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select can be used to pause for n number of milliseconds, so 3000 would be three seconds. Though this isn't the primary purpose for select, it's a useful side effect. What's useful about it is that you have more resolution than with sleep (which only has one-second granularity).

Probably a more Perlish solution than abusing select would be to use Time::HiRes (which I believe comes with Perl). Its use is as simple as sleep:

use Time::HiRes qw/ usleep /;

while( not defined $result ) {
    ( $result = try( $something ) ) or usleep( 3000 );
}
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Kudos to andyford for his comments. Yes, as was said sleep, or the Time::HiRes version of it will sleep for $n seconds. It may also be a bad idea. If you're program is waiting for a process it kicks of to finish, it may be better to have the process send a signal to your program.

Why do you want your program to wait a few seconds? Tell us that and you'll probably get a much better answer than 'use sleep.'

Cheers, Joost.