I want to select from a file all the lines which do not match a specific pattern;
I know I have to use -notMatch option of select-string but I just can’t figure it out how.
(I’m looking for something like GREP’s -v function)
Any example would be useful.
Thanks in advance.

I think you still want to match rather than notmatch. To exclude the function return type or comments, you need a ‘negative look behind asserion’. Perhaps this will do what you require?

The (?<!...) part says don’t match if ‘…’ is found at this point in the source text.