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

I don't know how I would do that with grep, but I would do something like this with awk:

awk '/abc/{ln1=NR} /efg/{ln2=NR} END{if(ln1 && ln2 && ln1 < ln2){print "found"}else{print "not found"}}' foo

You need to be careful how you do this, though. Do you want the regex to match the substring or the entire word? add \w tags as appropriate. Also, while this strictly conforms to how you stated the example, it doesn't quite work when abc appears a second time after efg. If you want to handle that, add an if as appropriate in the /abc/ case etc.