How can I tell Perl to run some code every 20 seconds?

Question

How can I tell Perl to run some code every 20 seconds?

Answer 1

#!/usr/bin/perl -w

use strict;


# heartbeat
$SIG{ALRM} = sub {
    # set up the next signal for 20 second from now
    alarm(20);
    printf "\n";
};

alarm(20); # start timer
my $i = 0;
while(1) {
    $i++;
    printf "loop" . $i . "\n";
    sleep 2;
}

alarm(0);

printf "done!\n";

Output :

loop1
loop2
loop3
loop4
loop5
loop6
loop7
loop8
loop9
loop10

loop11
loop12
loop13
loop14
loop15
loop16
loop17
loop18
loop19
loop20