How to check if a file contains a specific string using Bash

 In case if you want to check whether file does not contain a specific string, you can do it as follows.

if ! grep -q SomeString "$File"; then

  Some Actions # SomeString was not found

fi

from: https://stackoverflow.com/questions/11287861/how-to-check-if-a-file-contains-a-specific-string-using-bash