use strict; use warnings; use Test::More tests => 1; my @seq; my @want = ( '>NM_001 Homo sapiens ADA2 (CECR1) GATCCAA', '>NM_002 Homo sapiens IKBKG GGAGGTCTTTAGCTTTAGGGAAACCC', ); while () { chomp; if (/^>/) { push @seq, "$_ "; } else { $seq[-1] .= $_; } } is_deeply \@seq, \@want; __DATA__ >NM_001 Homo sapiens ADA2 (CECR1) GATCCAA >NM_002 Homo sapiens IKBKG GGAGGTCTTTAGCTTTAGGGAAACCC