How to find lines not matching a certain pattern - ie grep -v

[gnuist006]

Hi All,

Once in a while I have to do something to lines that do not have a certain 
string or set of strings in them. I know how to find lines with a string. I 
also know how to find lines with a set of strings, ie by using the regexp

string1\|string2\| ....

But I dont know how to find strings that do not have the string or strings.

For the moment, I have been doing this in bash using grep -v. I assume that 
this is also doable in awk and possibly sed. But I dont know how to do this in 
a direct manner in emacs.

One indirect method in emacs would be to search for the lines with the strings 
and label/mark them with # in the beginning.

Next, label/mark all the lines with @ in the beginning.

Next, replace all the @#'s in the beginning with # or even nothing, ie ""

Now, you can search for all the lines with @ in the beginning and do whatever 
to them.


I assume that this is such a common operation that there would be something 
cleaner and better for this in emacs already.

Cheers
Bolega