ISALPHA
if (!ISALPHA(n)) {
} while (ISALPHA(n) || ISDIGIT(n) || n == '_');
if (ISALPHA(c) && ISUPPER(c))
if (ISALPHA(*(t - 1))) {
if (ISALPHA(c) || (c > '7')) {
if (!ISALPHA(c) || (TOLOWER(c) != 'o' && TOLOWER(c) != 'i')) {
if (ISALPHA(*t) && ISLOWER(*t))
} else if (ISALPHA(*s)) {
if (!ISALPHA(*t) && !ISDIGIT(*t) && (*t != '_'))
if (ISALPHA(c)) {
if (ISALPHA(c)) {
if (ISALPHA(c)) {
if (ISALPHA(c)) {
if (ISALPHA(c)) {
if (!ISALPHA(c))
if (!ISALPHA(c))
if (!ISALPHA(*up) || ((*s & 0x5f) != (*up & 0x5f)))