perl -pi.bak -e 's[^#!/usr/local/bin/perl][#!/usr/bin/perl]' *.pl

##</code><code>##

perl -pi.bak -e 'BEGIN{$c=@ARGV};s[^#!/usr/local/bin/perl][#!/usr/bin/perl] && $c-- if $c> @ARGV' *.pl

##</code><code>##

#!/usr/bin/perl -w -i.bak
use strict
our $count=@ARGV;
while (<>) {
        if ($count > @ARGV) {
                s[^#!/usr/local/bin/perl][#!/usr/bin/perl];
                $count--;
        }
        print;
}