while ($forked > 0) {
    print "[$forked] ";
    last if (waitpid(-1,0) == -1);
    sleep 1;
}
[download]

#!/usr/bin/perl -w

use strict;
$|=1;

my %kids;
$SIG{CHLD} = \&REAPER;          # set handler for fork

for (1..10) {
    my $pid = fork();
    die "Fork failed" unless defined $pid;
    if ($pid == 0) {
        print "Hello $$\n";
        sleep 1;
        print "Bye $$\n";
        exit;
    } else {
        $kids{$pid} = 1;
        print "Started child $pid\n";
    }
}

foreach my $kid (keys %kids) {
    print "Waiting for [$kid]:\n";
    my $val;
    do {
        $val = waitpid($kid, 0);
    } until $val == -1;
    delete $kids{$kid};
}

print "Done\n";
exit;

sub REAPER {
    my $pid = wait;
    $SIG{CHLD} = \&REAPER;      # reinstall for sysV (not needed)
    print "Finished child process $pid" . ($? ? " with exit $?" : "") 
+. "\n";
    delete $kids{$pid};
}
[download]

Second, why are you using a handler? It seems to me you are not ( at least in this example ) gaining anything by installing a handler. You want the parent to handle reaping the children. Signal handlers are really only useful when you want something to happen outside the scope of the parent process and that "something" needs to happen immediately. I do not gather you are working like that. If a child waits a few seconds for you to reap it, will there be any harm?

This snippet is from a code that spawns N children and gives them something to do from a job queue. When a child finishes, ie exits, I simply spawn another child off. Note the loop at the end to wait for the last N children to finish.

while( @jobq ) {
    if ( $counter < $num_children ) {
        &SPAWN( $ref );
    }
    else {
        do {
           sleep 5;
           $dpid = waitpid( -1, 1 );
        } until $dpid;
        last if ( $dpid == -1 );  # No children left
        printf "%s has finished, spawning next child (%d left)\n", $tr
+acker{$dpi
d}, scalar @jobq;
        &SPAWN( $ref );
    }
}

do {
    sleep 5;
    $dpid = waitpid( -1, 1 );
    printf("%s has finished\n", $tracker{$dpid}) if(defined( $tracker{
+$dpid} )
    );
} until $dpid == -1;
[download]

mikfire

-- Randal L. Schwartz, Perl hacker