Does bash support word boundary regular expressions?

Question

I am trying to match on the presence of a word in a list before adding that word again (to avoid duplicates). I am using bash 4.2.24 and am trying the below:

Answer 1

You can use grep, which is more portable than bash's regexp like this:

if echo $foo | grep -q '\'; then 
    echo "MATCH"; 
else 
    echo "NO MATCH"; 
fi