Number lines of files.
Synopsis
nl [OPTION]... [FILE]...
Description
Writes each FILE to standard output, with line numbers added. If no FILE is specified, standard input is read.
Options
-b STYLE Body numbering style: a (all), t (non-empty), n (none).
-n FORMAT Number format: ln (left), rn (right), rz (right, zero-padded).
-w WIDTH Number width (default: 6).
-s SEP Separator after number (default: TAB).
-v START Starting line number (default: 1).
-i INCR Line number increment (default: 1).
Examples
$ nl file.txt
Number non-empty lines.
$ nl -ba file.txt
Number all lines, including blanks.
$ nl -n rz -w 3 file.txt
Right-justified, zero-padded line numbers.
See Also
cat, column