How can I grep complex strings in variables?

Question

I am trying to grep for a small string in a much larger string. Both strings are being stored as variables and here is a code example:

#!/bin/bash

long_str=$(m         


        

Answer 1

grep is for files or stdin. If you want to use a variable as stdin then you need to use bash's herestring notation:

if grep -q "$shrt_str" <<< "$long_str" ; then