Bash trick to return string from function - 10x faster than using subshell like $(cmd)

example.sh

function assign() {
    unset -v "$1" || echo "Invalid identifier: $1" >&2
    printf -v "$1" '%s' "$2"
}


function getHelloWorld() {
    # Return the value "Hello World!"
    local "$1" && assign "$1" "Hello World!"
}


# Note: No $ here - we are specifying a name of a variable, not the value of a variable.
getHelloWorld SOME_VAR
echo "$SOME_VAR"  # Echos "Hello World!"