Re: grep can help?

[Glenn Morris <gmorris+news@ast.cam.ac.uk>]

FCC wrote:

> Initially I was trying to use isearch for a regexp but only to
> search for those occurences which are not in comments (or which do
> not appear after the character !). After spending some time with
> Google, it turned out that this is not possible because one cannot
> "invert a match", which is what is required here.

M-x occur ^[^!C-qC-j]*regexp

ought to work (the C-qC-j bit gives you a newline).
It will be fooled by instances of your desired regexp occurring after
a string containing !, but I imagine that's unlikely. If you needed
to deal with that, you could cook up some elisp using f90-in-comment.

> Then came the idea to use grep.

I guess comp.unix.shell or somesuch place is the right place for grep
questions.