#! perl -slw
use strict;
use Benchmark::Timer;

our $N ||= 1e6;
my $T = new Benchmark::Timer;

my @array;
push @array, sprintf "Test%07d", int rand 32767 for 1 .. $N;

$T->start( 'sort -u' );
open my $pipe, "| u:sort -u > temp.tmp" or die $!;
print $pipe $_ for @array;
close $pipe;

open my $in, '<', 'temp.tmp' or die $!;
my $i = 0;
$array[ $i++ ] = $_ while <$in>;
close $in;
$#array = $i - 1; ## Corrected, with thanks to [johngg]

$T->stop( 'sort -u' );
$T->report;

printf "Array now contains %d uniq elements\n", scalar @array;
__END__
[ 8:17:47.37] c:\test>551753-2 -N=1e7
1 trial of sort -u (183.281s total)
Array now contains 32768 uniq elements