ctype(3C)                                               ctype(3C)



     NAME
          isalpha, isupper, islower, isdigit, isxdigit, isalnum,
          isspace,  ispunct,  isprint,  isgraph,  iscntrl,  isascii  -
          classify characters

     SYNOPSIS
          #include <ctype.h>

          int isalpha(c)
          int c;

          ...

     DESCRIPTION
          These macros classify character-coded integer values by
          table lookup.  Each is a predicate returning nonzero for
          true, zero for false.  isascii is defined on all integer
          values; the rest are defined only where isascii is true and
          on the single non-ASCII value EOF (-1); see intro(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 [0-9].

          isxdigit          c is a hexadecimal digit [0-9], [A-F] or
                            [a-f].

          isalnum           c is an alphanumeric (letter or digit).

          isspace           c is a space, tab, carriage return, new-
                            line, vertical tab, or form-feed.

          ispunct           c is a punctuation character (neither con-
                            trol nor alphanumeric).

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

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

          iscntrl           c is a delete character (0177) or an ordi-
                            nary control character (less than 040).

          isascii           c is an ASCII character, code less than
                            0200.





     April, 1990                                                     1

     ctype(3C)                                               ctype(3C)



     RETURN VALUE
          If the argument to any of these macros is not in the domain
          of the function, the result is undefined.

     SEE ALSO
          intro(3), ascii(5).

















































     2                                                     April, 1990