1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_CTYPE_H
3#define _LINUX_CTYPE_H
4
5#include <linux/compiler.h>
6
7/*
8 * NOTE! This ctype does not handle EOF like the standard C
9 * library is required to.
10 */
11
12#define _U 0x01 /* upper */
13#define _L 0x02 /* lower */
14#define _D 0x04 /* digit */
15#define _C 0x08 /* cntrl */
16#define _P 0x10 /* punct */
17#define _S 0x20 /* white space (space/lf/tab) */
18#define _X 0x40 /* hex digit */
19#define _SP 0x80 /* hard space (0x20) */
20
21extern const unsigned char _ctype[];
22
23#define __ismask(x) (_ctype[(int)(unsigned char)(x)])
24
25#define isalnum(c) ((__ismask(c)&(_U|_L|_D)) != 0)
26#define isalpha(c) ((__ismask(c)&(_U|_L)) != 0)
27#define iscntrl(c) ((__ismask(c)&(_C)) != 0)
28#define isgraph(c) ((__ismask(c)&(_P|_U|_L|_D)) != 0)
29#define islower(c) ((__ismask(c)&(_L)) != 0)
30#define isprint(c) ((__ismask(c)&(_P|_U|_L|_D|_SP)) != 0)
31#define ispunct(c) ((__ismask(c)&(_P)) != 0)
32/* Note: isspace() must return false for %NUL-terminator */
33#define isspace(c) ((__ismask(c)&(_S)) != 0)
34#define isupper(c) ((__ismask(c)&(_U)) != 0)
35#define isxdigit(c) ((__ismask(c)&(_D|_X)) != 0)
36
37#define isascii(c) (((unsigned char)(c))<=0x7f)
38#define toascii(c) (((unsigned char)(c))&0x7f)
39
40#if __has_builtin(__builtin_isdigit)
41#define isdigit(c) __builtin_isdigit(c)
42#else
43static inline int isdigit(int c)
44{
45 return '0' <= c && c <= '9';
46}
47#endif
48
49static inline unsigned char __tolower(unsigned char c)
50{
51 if (isupper(c))
52 c -= 'A'-'a';
53 return c;
54}
55
56static inline unsigned char __toupper(unsigned char c)
57{
58 if (islower(c))
59 c -= 'a'-'A';
60 return c;
61}
62
63#define tolower(c) __tolower(c)
64#define toupper(c) __toupper(c)
65
66/*
67 * Fast implementation of tolower() for internal usage. Do not use in your
68 * code.
69 */
70static inline char _tolower(const char c)
71{
72 return c | 0x20;
73}
74
75/* Fast check for octal digit */
76static inline int isodigit(const char c)
77{
78 return c >= '0' && c <= '7';
79}
80
81#endif
82

source code of linux/include/linux/ctype.h