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 ugrep released a few months ago:

ugrep 'abc(\n|.)+?efg'

This tool is highly optimized for speed. It's also GNU/BSD/PCRE-grep compatible.

Note that we should use a lazy repetition +?, unless you want to match all lines with efg together until the last efg in the file.