NAME
ctype: isdigit, isxdigit, islower, isupper, isalpha, isalnum, isspace, iscntrl, ispunct, isprint, isgraph, isascii - character handling

SYNOPSIS
#include <ccs/ctype.h>

int isdigit (c)
int c;

. . .

isascii (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 -1 (guaranteed not to be a character set member).

isdigit
    tests for the digits 0 through 9.

isxdigit
    tests for any character for which isdigit is true or for 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 ``printing character'' as defined by the character set.

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 do a table lookup.

SEE ALSO
conv(3L), ascii(5).

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