use strict; use warnings; use lib "/Library/Perl/5.10.0/"; use autodie; open FILE, "<", "data/04102013_loginlogs.txt" or die "Cannot open input file.\n"; open OUT, ">>", "output.txt" or die "Cannot open output file.\n"; while( my $line= ) { print OUT $line if $line =~ /unknown type\(0x134e\)\s+30\.6511\s+\(V6\.5\.1 FP1\)/; } close OUT; close FILE;