#!/usr/bin/perl use warnings; my $input = 'lines.txt'; open (FILE, "<", $input) or die "Can not open $input $!"; my @lines = ; close FILE; my @forlines=(); foreach(@lines){ if( ( defined $_) and !($_ =~ /^\s*$/)){ push(@forlines, $_); } } my @buffer = (); foreach $line(@forlines) { $line =~/(.*?);.*?;.*?;.*?;.*?;.*?;.*?;.*?;.*?;.*?(?:$)/; my $var = $1; foreach $line2(@forlines) { $line2 =~/(.*?);.*?;.*?;.*?;.*?;.*?;.*?;.*?;.*?;.*?(?:$)/; if ($line2 eq $line) { next; } if($var eq $1 and $line2 =~ /(.*?);.*?;SU LI IR ST;.*?;SU LI IR ST;.*?;.*?;.*?;.*?;.*?(?:$)/) { push @buffer, $line2; } } } foreach $line(@buffer) { @forlines = grep {!/$line/} @forlines; } open(my $file, '>', $input) or die "Could not open file '$input' $!"; truncate $file,0; print $file @forlines;