Return non-zero if pfx is a prefix of str. If it is, *ptr is set to
the address of the first character in str after the prefix.
@param str input string
@param pfx prefix to test
@param ptr updated if the prefix is matched inside str
@return non-zero if the prefix matches, zero otherwise
Return non-zero if pfx is a prefix of str. If it is, *ptr is set to the address of the first character in str after the prefix.
@param str input string @param pfx prefix to test @param ptr updated if the prefix is matched inside str @return non-zero if the prefix matches, zero otherwise