ctype(3C)                                               ctype(3C)



NAME
     isdigit, isxdigit, islower, isupper, isalpha, isalnum,
     isspace, iscntrl, ispunct, isprint, isgraph, isascii - char-
     acter handling

SYNOPSIS
     #include <ctype.h>

     int isdigit (c)
     int c;

DESCRIPTION
     The character classification macros listed below return
     nonzero for true, zero for false.  isascii is defined on all
     integer values; the rest are defined on valid members of the
     character set and on the single value EOF (guaranteed not to
     be a character set member, see stdio(3S)).

     isdigit        tests for the digits 0 through 9.

     isxdigit       tests for hexadecimal digits, any character
                    for which isdigit is true or which is one of
                    the letters a through f or A through F.

     islower        tests for any lowercase letter as defined by
                    the character set.

     isupper        tests for any uppercase letter as defined by
                    the character set.

     isalpha        tests for any character for which islower or
                    isupper is true and possibly any others as
                    defined by the character set.

     isalnum        tests for any character for which isalpha or
                    isdigit is true.

     isspace        tests for a space, horizontal-tab, carriage
                    return, newline, vertical-tab, or form-feed.

     iscntrl        tests for ``control characters'' as defined
                    by the character set.

     ispunct        tests for any character other than the ones
                    for which isalnum, iscntrl, or isspace is
                    true or space.

     isprint        tests for a space or any character for which
                    isalnum or ispunct is true or other ``print-
                    ing character'' as defined by the character
                    set.




Page 1                        CX/UX Programmer's Reference Manual

ctype(3C)                                               ctype(3C)



     isgraph        tests for any character for which isprint is
                    true, except for space.

     isascii        tests for an ASCII character (a non-negative
                    number less than 0200.)

     All the character classification macros except isascii do a
     table lookup.

     The tables used by these macros may be loaded by
     setlocale(3C) or by setchrclass(3C) to correspond to a
     specific locale.

SEE ALSO
     conv(3C), stdio(3S), setchrclass(3C), setlocale(3C),
     ascii(5), environ(5).
     chrtbl(1M) in the CX/UX Administrator's Reference Manual.

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


































Page 2                        CX/UX Programmer's Reference Manual