nl --help

code:nl --help

Write each FILE to standard output, with line numbers added.

With no FILE, or when FILE is -, read standard input.

Mandatory arguments to long options are mandatory for short options too.

-b, --body-numbering=STYLE use STYLE for numbering body lines

-d, --section-delimiter=CC use CC for logical page delimiters

-f, --footer-numbering=STYLE use STYLE for numbering footer lines

-h, --header-numbering=STYLE use STYLE for numbering header lines

-i, --line-increment=NUMBER line number increment at each line

-l, --join-blank-lines=NUMBER group of NUMBER empty lines counted as one

-n, --number-format=FORMAT insert line numbers according to FORMAT

-p, --no-renumber do not reset line numbers for each section

-s, --number-separator=STRING add STRING after (possible) line number

-v, --starting-line-number=NUMBER first line number for each section

-w, --number-width=NUMBER use NUMBER columns for line numbers

--help display this help and exit

--version output version information and exit

By default, selects -v1 -i1 -l1 -sTAB -w6 -nrn -hn -bt -fn.

CC are two delimiter characters used to construct logical page delimiters,

a missing second character implies :. Type \\ for \. STYLE is one of:

a number all lines

t number only nonempty lines

n number no lines

pBRE number only lines that contain a match for the basic regular

expression, BRE

FORMAT is one of:

ln left justified, no leading zeros

rn right justified, no leading zeros

rz right justified, leading zeros

or available locally via: info '(coreutils) nl invocation'