print MERGE pack('A20A180A200A350',@vars);

##</code><code>##

#!/usr/local/bin/perl

use Benchmark;
use strict;

my $count = 10000;
my @lists = map { [chr($_+65),chr($_+66),chr($_+67),chr($_+68) ] } 0..22;

open(FH1,'>/tmp/x') or die "$!\n";
open(FH2,'>/tmp/y') or die "$!\n";

timethese ($count, { 'pack' => '&use_pack', 'printf' => '&use_printf' } );

sub use_pack {
    foreach (@lists) {
        print FH1 pack('A20A180A200A350',@{$_});
    }
}

sub use_printf {
    foreach (@lists) {
        printf FH2 "%-20s%-180s%-200s%-350s", @{$_} ;
    }

}

##</code><code>##

Benchmark: timing 10000 iterations of pack, printf...
      pack: 21 wallclock secs (10.10 usr +  9.55 sys = 19.65 CPU) @ 508.91/s (n=10000)
    printf: 24 wallclock secs (10.90 usr +  9.72 sys = 20.62 CPU) @ 484.97/s (n=10000)

Benchmark: timing 10000 iterations of pack, printf...
      pack: 21 wallclock secs (10.03 usr +  9.75 sys = 19.78 CPU) @ 505.56/s (n=10000)
    printf: 23 wallclock secs (11.88 usr + 10.72 sys = 22.60 CPU) @ 442.48/s (n=10000)