nl
$ nl [--body-numbering style] [--increment number] [--separator string] [--startnum number] [--width number] [file...]
-b style
, --body-numbering style
: Line numbering style: 't' for non-empty lines, 'a' for all lines, 'n' for no lines-i number
, --increment number
: Line count increment-s string
, --separator string
: Separator between line numbers and lines-v number
, --startnum number
: Initial line number-w number
, --width number
: Number widthfile
: Files to process