regular expression for anything but an empty string

Question

Is it possible to use a regular expression to detect anything that is NOT an \"empty string\" like this:

string s1 = \"\";
string s2 = \" \";
string s3 = \"          


        

Answer 1

Create "regular expression to detect empty string", and then inverse it. Invesion of regular language is the regular language. I think regular expression library in what you leverage - should support it, but if not you always can write your own library.

grep --invert-match