nl [ -i ] line number increment at each line

commandline session $cat comma.pl use strict; use warnings; for (qw/ 179550 45960 890458 -12345678 1000000000000/) { (my $n = $_) =~ s/(d+?)(?=(d{3})+b)/$1,/g; print “$nn”; } $nl comma.pl 1 use strict; 2 use warnings; 3 for (qw/ 179550 45960 890458 -12345678 1000000000000/) { 4 (my $n = $_) =~ s/(d+?)(?=(d{3})+b)/$1,/g; 5 print “$nn”; 6 } $nl …