note manorhce <p>You don't have fixed width of line, look behind or look ahead will only work on fixed width</p> <code>use strict; use warnings; while(my $line = <DATA>) { chomp($line); if( $line =~ /(?<!fee\/src\/)(com\/)/ ) { print $line . "\n"; } } __DATA__ foo/src/com/ foo/src/com/ foo/src/com/ fee/src/com/</code> 1018345 1018345