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

Why not something simple like:

egrep -o 'abc|efg' $file | grep -A1 abc | grep efg | wc -l

returns 0 or a positive integer.

egrep -o (Only shows matches, trick: multiple matches on the same line produce multi-line output as if they are on different lines)

• grep -A1 abc (print abc and the line after it)

• grep efg | wc -l (0-n count of efg lines found after abc on the same or following lines, result can be used in an 'if")

• grep can be changed to egrep etc. if pattern matching is needed