ISXDIGIT(3) Library Functions Manual ISXDIGIT(3)

isxdigit
hexadecimal-digit character test

Standard C Library (libc, -lc)

#include <ctype.h>

int
isxdigit(int c);

The isxdigit() function tests for any hexadecimal-digit character.

The isxdigit() function returns zero if the character tests false and returns non-zero if the character tests true.

ctype(3), isalnum(3), isalpha(3), isascii(3), isblank(3), iscntrl(3), isdigit(3), isgraph(3), islower(3), isprint(3), ispunct(3), isspace(3), isupper(3), stdio(3), toascii(3), tolower(3), toupper(3), ascii(7)

The isxdigit() function conforms to ANSI X3.159-1989 (“ANSI C89”).

The argument to isxdigit() must be EOF or representable as an unsigned char; otherwise, the behavior is undefined. See the CAVEATS section of ctype(3) for more details.
April 17, 2008 NetBSD 9.2