Return a regex match in a Bash script, instead of replacing it

Question

I just want to match some text in a Bash script. I\'ve tried using sed but I can\'t seem to make it just output the match instead of replacing it with something.

Answer 1

using just the bash shell

declare -a array
i=0
while read -r line
do
        case "$line" in
            *TestT*String* )
            while true
            do
                line=${line#*TestT}
                array[$i]=${line%%String*}
                line=${line#*String*}
                i=$((i+1))
                case "$line" in
                    *TestT*String* ) continue;;
                    *) break;;
                esac
            done
            esac
done <"file"
echo ${array[@]}