NAME

     ctype, isalpha, isupper, islower, isdigit,  isxdigit,  isal-
     num,  isspace,  ispunct, isprint, isgraph, iscntrl, isascii,
     toupper, tolower, toascii - character classification macros


SYNOPSIS

     #include <ctype.h>

     int isalpha(int c)
     ...


DESCRIPTION

     These macros classify characters by table lookup.  Each is a
     predicate  returning  nonzero  for  true,  zero  for  false.
     Isascii and toascii are defined on all integer  values;  the
     rest  are  defined only on the range of unsigned char and on
     the special value EOF (see stdio(3)).

     isalpha        c is a letter

     isupper        c is an upper case letter

     islower        c is a lower case letter

     isdigit        c is a digit

     isxdigit       c is a hex digit

     isalnum        c is an alphanumeric character

     isspace        c is a space, tab, carriage return,  newline,
                    vertical tab, or formfeed

     ispunct        c is a punctuation character (neither control
                    nor alphanumeric)

     isprint        c  is  a  printing  character,  code   040(8)
                    (space) through 0176 (tilde)

     isgraph        c is a printing character, similar to isprint
                    except false for space.

     iscntrl        c is a delete character  (0177)  or  ordinary
                    control character (less than 040).

     isascii        c is an ASCII character, code less than 0200

     tolower        c is converted to lower case.   Return  value
                    is undefined if not isupper(c).

     toupper        c is converted to upper case.   Return  value
                    is undefined if not islower(c).

     toascii        c is converted to be a valid ascii character.


SEE ALSO

     ascii(7)