I use it a bit in Vim find/replace. Nothing crazy. I originally learned it because I made some text file editing programs in Perl, back when that was the thing

I use it a bit in Vim find/replace. Nothing crazy. I originally learned it because I made some text file editing programs in Perl, back when that was the thing to use. I don't know a lot, just enough to get by. I don't know if that counts. For example, if I want to find a function definition for foo in C and I don't know its return type: ^\s*\w+\s+foo\s*(.*) That would find it. Probably.