Non-greedy regular expression match for multicharacter delimiters in awk

Question

Consider the string \"AB 1 BA 2 AB 3 BA\". How can I match the content between \"AB\" and \"BA\" in a non-greedy fashion (in awk)?

Answer 1

For general expressions, I'm using this as a non-greedy match:

function smatch(s, r) {
    if (match(s, r)) {
        m = RSTART
        do {
            n = RLENGTH
        } while (match(substr(s, m, n - 1), r))
        RSTART = m
        RLENGTH = n
        return RSTART
    } else return 0
}

smatch behaves like match, returning:

the position in s where the regular expression r occurs, or 0 if it does not. The variables RSTART and RLENGTH are set to the position and length of the matched string.