CTYPE(3C-SysV)      RISC/os Reference Manual       CTYPE(3C-SysV)



NAME
     ctype: isalpha, isupper, islower, isdigit, isxdigit, isal-
     num, 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 stdio(3S)].

     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
                         control nor alphanumeric).

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

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

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

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




                         Printed 1/15/91                   Page 1

CTYPE(3C-SysV)      RISC/os Reference Manual       CTYPE(3C-SysV)



SEE ALSO
     stdio(3S), ascii(5).

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

















































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