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NL

Section: User Commands (1)
Updated: February 2026
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NAME

nl - number lines of files

SYNOPSIS

nl [,OPTION/]... [,FILE/]...

DESCRIPTION

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.

X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#n-b'-b, --body-numbering=,STYLEX'tty: link'/: use STYLE for numbering body lines
X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#n-d'-d, --section-delimiter=,CCX'tty: link'/: use CC for logical page delimiters
X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#n-f'-f, --footer-numbering=,STYLEX'tty: link'/: use STYLE for numbering footer lines
X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#n-h'-h, --header-numbering=,STYLEX'tty: link'/: use STYLE for numbering header lines
X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#n-i'-i, --line-increment=,NUMBERX'tty: link'/: line number increment at each line
X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#n-l'-l, --join-blank-lines=,NUMBERX'tty: link'/: group of NUMBER empty lines counted as one
X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#n-n'-n, --number-format=,FORMATX'tty: link'/: insert line numbers according to FORMAT
X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#n-p'-p, --no-renumberX'tty: link': do not reset line numbers for each section
X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#n-s'-s, --number-separator=,STRINGX'tty: link'/: add STRING after (possible) line number
X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#n-v'-v, --starting-line-number=,NUMBERX'tty: link'/: first line number for each section
X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#n-w'-w, --number-width=,NUMBERX'tty: link'/: use NUMBER columns for line numbers
X'tty: link https://www.gnu.org/software/coreutils/nl#n-help'--helpX'tty: link': display this help and exit
X'tty: link https://www.gnu.org/software/coreutils/nl#n-version'--versionX'tty: link': output version information and exit

Default options are: -bt -d':' -fn -hn -i1 -l1 -n'rn' -s<TAB> -v1 -w6

CC are two delimiter characters used to construct logical page delimiters; a missing second character implies ':'. As a GNU extension one can specify more than two characters, and also specifying the empty string (-d '') disables section matching.

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

AUTHOR

Written by Scott Bartram and David MacKenzie.

REPORTING BUGS

Report bugs to: bug-coreutils@gnu.org

Report Gentoo bugs to: https://bugs.gentoo.org/
GNU coreutils home page: <https://www.gnu.org/software/coreutils/>
General help using GNU software: <https://www.gnu.org/gethelp/>
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