#!/usr/bin/perl use warnings; use strict; while (){ my $string = $_; if ($string =~ /[ATGC]{8}/) { print "$string"; } } __DATA__ @3009W:27:32 GCTCT + %.8:9 @3009W:27:40 TTGGG + 0(*2+ @3009W:31:26 AGCCT + 5<=46 @3009W:31:35 TCAGAAAACTG + 0.5*.--%-0- @3009W:32:34 GGGCCTAACCTGGGAGCCCCT + A@.:158+,--*-%-**--%- @3009W:34:32 CCATCATCTGGGG + :-:>>;;55755& @3009W:36:21 GACTT + (8.7( @3009W:40:24 ATGATCC + 44.0,.% @3009W:42:22 GCTTCCAGGGTCAGTTTGGGAAAC + :@>4;4888)1//**-%+5+25,. @3009W:47:23 GAGCATCGA + %*1.0...- @3009W:49:23 GAGTTCCATCGAAATGTACAAGCTTTACGTTTAAAAC + /3....0304036-22.,--(*.09*00,11),00(. @3009W:14:90 AGCAA + 82528 @3009W:17:84 GAAACACAC + 05?4=:<:0 @3009W:17:95 TTTTTCTTT + ;<<<-07<1 @3009W:19:89 CCTCTACC + ?:>>:;83 @3009W:19:90 AAGAA + :4<;2 @3009W:20:74 GGTTCC + 2&-.2. @3009W:22:94 CATTTGGAA + AAAB9>8>: @3009W:23:79 CTTACAA + @@9@@@@ @3009W:23:93 TCTTTTTC + @@@AAA/A @3009W:24:80 GTGAGC + BC @3009W:26:99 ATCCATAT + /88(3979 @3009W:27:83 AGGCA + AA>@@