How to check if a string contains a substring in Bash

Question

I have a string in Bash:

string=\"My string\"

How can I test if it contains another string?

if [ $string ?? \'foo\' ]; then         


        

Answer 1

How about this:

text="   bmnmn  "
if [[ "$text" =~ "" ]]; then
   echo "matched"
else
   echo "not matched"
fi