nl(1)

nl -- number lines

Synopsis

nl [-btype] [-ftype] [-htype] [-vstart#] [-iincr] [-p] [-lnum] [-ssep] [-wwidth] [-nformat] [-ddelim] [file]

Description

nl 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 effect. nl processes supplementary code set characters according to the locale specified in the LC_CTYPE environment variable (see LANG on environ(5)), except as noted below. In regular expressions, pattern searches are performed on characters, not bytes, as described on grep(1).

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 sections.

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.

If POSIX2 is in the environment, then there is no default value for the options -b, -f, -h, -v, -i, -l, -s, -w, -n or -d. If the value isn't immediately after the option variable, then it is the next argument.

The options are:

-btype

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

a: number all lines
t: number lines with printable text only
n: do not number lines
pexp: number only lines that contain the basic regular expression (BRE) exp (see grep(1))

Default type for logical page body is t (text lines numbered). All supplementary code set characters are considered printable.

-ftype

Same as -btype except for footer. Default type for logical page footer is n (no lines numbered). All supplementary code set characters are considered printable.

-htype

Same as -btype except for header. Default type for logical page header is n (no lines numbered). All supplementary code set characters are considered printable.

-vstart#

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

-iincr

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

-p

Do not restart numbering at logical page delimiters.

-lnum

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.

-ssep

sep is the character(s) used in separating the line number and the corresponding text line. Default sep is a tab. sep must be a single-byte character or characters.

-wwidth

width is the number of characters to be used for the line number. Default width is 6. The maximum for width is 100. If a number greater than the maximum is specified for width, the maximum is automatically used.

-nformat

format is the line numbering format. Recognized values are: ln, left justified, leading zeroes suppressed; rn, right justified, leading zeroes suppressed; rz, right justified, leading zeroes kept. Default format is rn (right justified).

-ddelim

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. delim must be a single-byte character or characters.

Examples

The command:

nl -v10 -i10 -d!+ file1

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 ``!+''.

Files

/usr/lib/locale/locale/LC_MESSAGES/uxdfm: language-specific message file (See LANG on environ(5).)

References

ed(1), pr(1)