isalpha, isupper, islower, isdigit, isalnum, isspace, ispunct, isprint, iscntrl, isascii \- character classification
These macros classify ASCII-coded integer values
Each is a predicate returning nonzero for true,
is defined on all integer values; the rest
is true and on the single non-ASCII value
is an alphanumeric character
is a space, tab, carriage return, newline, or formfeed
is a punctuation character (neither control nor alphanumeric)
is a printing character, code 040(8) (space) through 0176 (tilde)
is a delete character (0177) or ordinary control character
is an ASCII character, code less than 0200