Operating system | Unix and Unix-like |
---|---|
Platform | Cross-platform |
Type | Command |
License | coreutils: GPLv3+ |
nl is a Unix utility for numbering lines, either from a file or from standard input, reproducing output on standard output.
nl is part of the X/Open Portability Guide since issue 2 of 1987. It was inherited into the first version of POSIX.1 and the Single Unix Specification. It first appeared in System V release 2.
The version of nl bundled in GNU coreutils was written by Scott Bartram and David MacKenzie.
The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities.
The command has a number of switches:
The default applied switch is t.
nl also supports some command line options.
The following example numbers only the lines that begin with a capital letter A (matching on the regular expression /^A/). filename is optional.
$ nl -b p^A filename apple 1 Apple BANANA 2 Allspice strawberryIt can be useful as an alternative to grep -n:
$ cat somefile aaaa bbbb cccc dddc $ nl somefile | grep cccc 3 ccccUnix command-line interface programs and shell builtins | |
---|---|
File system | |
Processes | |
User environment | |
Text processing | |
Shell builtins | |
Searching | |
Documentation | |
Software development | |
Miscellaneous | |
|
GNU Core Utilities command-line interface programs | |
---|---|
File system | |
Text utilities | |
Shell utilities |