Re: grep for ^ as a single word

[Julian Foad]

Szlovencsak Attila wrote:
> If I want to grep out all lines with a single '^' character as a word, I 
> say
>
> grep '\b\^\b' /tmp/test
>
> but it does not give back the first two lines of the file, as expected.

This is working as intended.  Grep's definition of a "word" for these purposes 
is not what you think it is.  You can find the definition in the manual, in the 
description of "-w":

>      -w, --word-regexp
>             Select  only  those  lines  containing  matches  that form whole
>             words.  The test is that the matching substring must  either  be
>             at  the  beginning  of  the line, or preceded by a non-word con‐
>             stituent character.  Similarly, it must be either at the end  of
>             the line or followed by a non-word constituent character.  Word-
>             constituent characters are letters, digits, and the  underscore.

- Julian