Regular Expression to find a string included between two characters while EXCLUDING the delimiters

Question

I need to extract from a string a set of characters which are included between two delimiters, without returning the delimiters themselves.

A simple example should b

Answer 1

If you need extract the text without the brackets, you can use bash awk

echo " [hola mundo] " | awk -F'[][]' '{print $2}'

result:

hola mundo