ossl_isalnum
if (!ossl_isalnum(buf[0]))
if (!ossl_isalnum(str[i]) && str[i] != '.' && str[i] != '_') {
} while (*++s == '_' || ossl_isalnum(*s));
&& TEST_int_eq(isalnum(n) != 0, ossl_isalnum(n) != 0)