How to find patterns across multiple lines using grep?

Question

I want to find files that have \"abc\" AND \"efg\" in that order, and those two strings are on different lines in that file. Eg: a file with content:

blah bl         


        

Answer 1

With silver searcher:

ag 'abc.*(\n|.)*efg'

similar to ring bearer's answer, but with ag instead. Speed advantages of silver searcher could possibly shine here.