linux/include/linux/ctype.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_CTYPE_H
#define _LINUX_CTYPE_H

#include <linux/compiler.h>

/*
 * NOTE! This ctype does not handle EOF like the standard C
 * library is required to.
 */

#define _U …
#define _L …
#define _D …
#define _C …
#define _P …
#define _S …
#define _X …
#define _SP …

extern const unsigned char _ctype[];

#define __ismask(x) …

#define isalnum(c) …
#define isalpha(c) …
#define iscntrl(c) …
#define isgraph(c) …
#define islower(c) …
#define isprint(c) …
#define ispunct(c) …
/* Note: isspace() must return false for %NUL-terminator */
#define isspace(c) …
#define isupper(c) …
#define isxdigit(c) …

#define isascii(c) …
#define toascii(c) …

#if __has_builtin(__builtin_isdigit)
#define isdigit …
#else
static inline int isdigit(int c)
{ … }
#endif

static inline unsigned char __tolower(unsigned char c)
{ … }

static inline unsigned char __toupper(unsigned char c)
{ … }

#define tolower(c) …
#define toupper(c) …

/*
 * Fast implementation of tolower() for internal usage. Do not use in your
 * code.
 */
static inline char _tolower(const char c)
{ … }

/* Fast check for octal digit */
static inline int isodigit(const char c)
{ … }

#endif