#!/usr/bin/perl

open my $fh, '>>', '/tmp/out' or die "open: $!\n";

sub output {
    my ($id) = @_;
    my $line = sprintf "[%02d: my id is: %02d]\n", $id, $id; # 19 chars
    print $fh $line x 500;  # bigger than 8K, and $line straddles boundary
    warn "$id: sleeping...\n";
    sleep 1;
    warn "$id: exiting\n";
    exit;
}

for (1..3) {
    sleep 1;
    warn "$_: spawning...\n";
    my $pid = fork();
    die "fork failed: $!\n" unless defined $pid;
    next if $pid;
    # child
    output($_);
}
sleep 5;
__END__