I want to search for a string which matches regex [A-Z]+(?:19|20)\d\d in a file in centos.
I am using below command for the same:
grep -F '[A-Z]+(?:19|20)\d\d' <file_name>
It does not seem to work.
I ended up escaping .^$*+?()[{\| but still no luck.
I wanted to know if am incorrect somewhere, can anyone please help ?
