use warnings 'all'; use strict; use autodie; my $filename = 'numbers.txt'; my $outfile = 'sum.txt'; open(my $in, '<', $filename); open(my $out, '>', $outfile); while (my $numbers = <$in>) { chomp $numbers; my $sum = eval $numbers; print $out $sum, "\n"; } close $out; close $in;