nl - line numbering filter

nl reads lines from the file file or from standard input if file is omitted or is -, and writes the lines to standard output with possible line numbering preceding each line.

The nl utility treats its input in terms of logical pages and resets numbering on each logical page. A logical page consists of a header, a body, and a footer any of which can be empty, and each can use their own line numbering options.

The start of logical page sections consist of input lines containing only the two delimiter characters whose defaults are \ and : as follows:

d1d2d1d2d1d2

Header.

d1d2d1d2

Body.

d1d2

Footer.

nl assumes that the first section is a logical body until it encounters one of the section delimiters.

-b, --body-numbering=type

type can be one of the following:

a

Number all lines.

t

Number only non-empty lines.

n

No line numbering.

pstring

Number only lines that contain the basic regular expression string.

The default value is t.

-d, --section-delimiter=delim

delim specifies the two delimiter characters that indicate start of a section. If only one character is specified, the second character remains unchanged. The default value is \:.

-f, --footer-numbering=type

type is the same as for the b option. The default value is n .

-h, --header-numbering=type

type is the same as for the b option. The default value is n .

-i, --page-increment=incr

incr is the increment used to number logical page lines. The default value is 1.

-l, --join-blank-lines=num

num is the number of blank lines to be treated as one The default value is 1.

-n, --number-format=format

format specifies the line numbering format. It must be one of the following:

ln

left justified, leading zeros supressed.

rn

right justified, leading zeros supressed.

rz

right justified, leading zeros kept.

-p, --no-renumber

Start renumbering at logical page delimiters.

-s, --number-separator=sep

sep is the string that is used to separate the line number and the corresponding text line. The default value is \t.

-v, --starting-line-number=startnum

startnum is the initial value to number logical pages. The default value is 1.

-w, --number-width=width

width is the number of characters to be used for line numbering. The default value is 6.

0

Success.

>0

An error occurred.

pr(1), regex(3)

version

nl (AT&T Research) 2003-03-24

author

David Korn <dgk@research.att.com>

copyright

Copyright © 2003-2012 AT&T Intellectual Property

license

http://www.eclipse.org/org/documents/epl-v10.html