millfork/include/string.mfk

#if ARCH_I80

byte strzlen(pointer str) {
    pointer end
    end = str
    while end[0] != 0 {
        end += 1
    }
    return lo(end - str)
}

#else

byte strzlen(pointer str) {
    byte index
    index = 0
    while str[index] != 0 {
        index += 1
    }
    return index
}
#endif