aaa,1 bbb,2 ccc,3 SUCCESS aaa : a 3 : 1 bbb #### aaa,1 bbb,2 ccc,3 ac 1,a 3,b 2,c Argument "1 bbb" isn't numeric in numeric eq (==) at z line 20, line 1 (#1) (W numeric) The indicated string was fed as an argument to an operator that expected a numeric value instead. If you're fortunate the message will identify which operator was so unfortunate. readline() on closed filehandle FHAC at z line 20 (#2) (W closed) The filehandle you're reading from got itself closed sometime before now. Check your control flow. SUCCESS aaa : a 3 : 1 bbb #### use strict; use warnings; use diagnostics; use autodie; open( OUTFH, ">outputfile.log" ); print OUTFH "here is some output\n"; print OUTFH "here is more output\n"; close(OUTFH);