Nl (Unix)

nl is a Unix utility for numbering lines, either from a file or from standard input, reproducing output on standard output.

It has a number of switches:

*a - number all lines *t - number lines with printable text only *n - no line numbering *string - number only those lines containing the regular expression defined in the string supplied.

The default applied switch is t .

nl also supports a number of command line options.