$ cat 6.fork.pl
#!/usr/bin/perl -w
use 5.011;

my $start = time;

if (fork() == 0) {
 # arm the alarm clock
 alarm(10);
 # create a child process that sleeps
 system("ping www.google.com >5.fork.txt");
 exit(0);
}
say "relevant processes with pstree command:";
system("pstree -Apal $$");

while((my $pid = wait()) != -1) {
 say "$pid terminated"
}
system("cat 5.fork.txt");
say time-$start, " ? <-ten seconds elapsed from forked process"
__END__
$