Editing Nl (Unix) (section)

==Example==
<syntaxhighlight lang="bash">
 $ nl tf
     1  echo press cr
     2  read cr
     3  done
</syntaxhighlight>
The following example numbers only the lines that begin with a capital letter A (matching on the [[regular expression]] /^A/).  ''filename'' is optional.
<syntaxhighlight lang="console">
$ nl -b p^A filename
       apple
    1  Apple
       BANANA
    2  Allspice
       strawberry
</syntaxhighlight>
It can be useful as an alternative to {{mono|[[grep|grep -n]]}}:
<syntaxhighlight lang="console">
$ cat somefile
aaaa
bbbb
cccc
dddc
$ nl somefile | grep cccc
    3 cccc
</syntaxhighlight>