RE: Nested grep

["Drew Adams" <drew.adams@oracle.com>]

> When grepping for something I often follow a certain match and do
> another grep to find out more about it. The problem is this eliminates
> the original grep buffer (with matches, current state, etc.), so I have
> to redo that grep (and start from the first match again if I use
> next-error) to continue investigating other matches.
>
> I'd like a nested grep feature for starting an other grep with the
> ability to return easily to the previous grep results after I'm
> finished with the current one.
>
> Is there an existing package which does something like that?

In Emacs 22 you can pipe the output of one grep to another: grep foo|grep
bar|grep toto. Just type that at the grep prompt.

You might also be interested in Icicles command `icicle-compilation-search'
(`C-c `' in buffer *grep*), which lets you search among grep hits using
additional regexps -
http://www.emacswiki.org/cgi-bin/wiki/Icicles_-_Other_Search_Commands.