NL(1) User Commands NL(1)


nl - line numbering filter


/usr/bin/nl [-p] [-b [type]] [-d [delim]] [-f [type]]
[-h [type]] [-i [incr]] [-l [num]] [-n [format]]
[-s [sep]] [-w [width]] [-v [startnum]] [file]

/usr/xpg4/bin/nl [-p] [-b type] [-d delim] [-f type]
[-h type] [-i incr] [-l num] [-n format] [-s sep]
[-w width] [-v startnum] [file]


The nl utility reads lines from the named file, or the standard input if
no file is named, and reproduces the lines on the standard output. Lines
are numbered on the left in accordance with the command options in

nl views the text it reads in terms of logical pages. Line numbering is
reset at the start of each logical page. A logical page consists of a
header, a body, and a footer section. Empty sections are valid. Different
line numbering options are independently available for header, body, and
footer. For example, -bt (the default) numbers non-blank lines in the
body section and does not number any lines in the header and footer

The start of logical page sections are signaled by input lines containing
nothing but the following delimiter character(s):

|Line contents | Start Of |
|\:\:\: | header |
|\:\: | body |
|\: | footer |

Unless optioned otherwise, nl assumes the text being read is in a single
logical page body.


Command options may appear in any order and may be intermingled with an
optional file name. Only one file may be named. The specified default is
used when the option is not entered on the command line. /usr/xpg4/bin/nl
options require option arguments. A SPACE character may separate options
from option arguments. /usr/bin/nl options may have option arguments. If
option-arguments of /usr/bin/nl options are not specified, these options
result in the default. The supported options are:

Specifies which logical page body lines are to be numbered.
Recognized types and their meanings are:

number all lines

number all non-empty lines.

no line numbering

number only lines that contain the regular
expression specified in exp. See NOTES below.

Default type for logical page body is t (text lines

Same as -btype except for footer. Default type for logical
page footer is n (no lines numbered).

The two delimiter characters specifying the start of a
logical page section may be changed from the default
characters (\:) to two user-specified characters. If only
one character is entered, the second character remains the
default character (:). No space should appear between the
-d and the delimiter characters. To enter a backslash, use
two backslashes.

Same as -btype except for header. Default type for logical
page header is n (no lines numbered).

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

num is the number of blank lines to be considered as one.
For example, -l2 results in only the second adjacent blank
being numbered (if the appropriate -ha, -ba, and/or -fa
option is set). Default num is 1.

format is the line numbering format. Recognized values are:

left justified, leading zeroes suppressed

right justified, leading zeroes suppressed

right justified, leading zeroes kept

Default format is rn (right justified).

Do not restart numbering at logical page delimiters.

sep is the character(s) used in separating the line number
and the corresponding text line. Default sep is a TAB.

startnum is the initial value used to number logical page
lines. Default startnum is 1.

width is the number of characters to be used for the line
number. Default width is 6.


The following operand is supported:

A path name of a text file to be line-numbered.


Example 1: An example of the nl command

The command:

example% nl -v10 -i10 -d!+ filename1

will cause the first line of the page body to be numbered 10, the second
line of the page body to be numbered 20, the third 30, and so forth. The
logical page delimiters are !+.


See environ(7) for descriptions of the following environment variables
that affect the execution of nl: LANG, LC_ALL, LC_COLLATE, LC_CTYPE,


The following exit values are returned:

Successful completion.

An error occurred.



Collation table generated by localedef


Shared object containing string transformation library routines


See attributes(7) for descriptions of the following attributes:


|Interface Stability | Standard |


pr(1), attributes(7), environ(7), regex(7), regexp(7), standards(7)


Internationalized Regular Expressions are used in the POSIX and "C"
locales. In other locales, Internationalized Regular Expressions are used
if the following two conditions are met:

o /usr/lib/locale/locale/LC_COLLATE/CollTable is present.

o /usr/lib/locale/locale/LC_COLLATE/ is not present.

Otherwise, Simple Regular Expressions are used.

Internationalized Regular Expressions are explained on regex(7). Simple
Regular Expressions are explained on regexp(7).

illumos March 28, 1995 NL(1)