#!/usr/bin/perl $key = "fa01"; $filename = "blast_results/$key_blast"; $filename2 = "blast_results/$key_index"; $index_start = 0; open (FILE, "$filename"); while ($line = ) { $index = tell(FILE); chop $line; if ($line =~/$key/) {$codes{$line} = $index; } } close (FILE); open (FILE2, ">$filename2"); foreach $line (sort (keys(%codes))) { print FILE2 "$line, $codes{$line}\n"; print "$ line, $codes{$ line}\n"; } close (FILE2); print "done\n\n";