#!/usr/bin/perl -w
use strict;

my $count = shift;
my $interval = 60 / $count;

for (1..$count) {
    system(@ARGV);
    select(undef,undef,undef,$interval);
}

##</code><code>##

#!/usr/bin/perl -w
use strict;

my $count = shift;
my $interval = 60 / $count;
my ($pid,%kids);

for (1..$count) {
    defined($pid = fork()) or warn $! and last; # can't die, kids to tend
    $pid or exec(@ARGV);
    $kids{$pid}++;
    select(undef,undef,undef,$interval);
}

delete $kids{wait()} while %kids;