#!/bin/perl use warnings; use strict; my $i =0; my $x; my $aa = ""; for ($i;$i<5007;$i++){ $x = int(rand(4)); if ($x == 0) { $aa .= 'A'; } elsif ($ x== 1) { $aa .= 'T'; } elsif ($x == 2) { $aa .= 'C'; } else { $aa .= 'G'; } } open (FILE, '>./test'); print FILE "$aa"; close (FILE);