esp-idf/components/newlib/include/ctype.h

#ifndef _CTYPE_H_
#define _CTYPE_H_

#include "_ansi.h"

_BEGIN_STD_C

int _EXFUN(isalnum, (int __c));
int _EXFUN(isalpha, (int __c));
int _EXFUN(iscntrl, (int __c));
int _EXFUN(isdigit, (int __c));
int _EXFUN(isgraph, (int __c));
int _EXFUN(islower, (int __c));
int _EXFUN(isprint, (int __c));
int _EXFUN(ispunct, (int __c));
int _EXFUN(isspace, (int __c));
int _EXFUN(isupper, (int __c));
int _EXFUN(isxdigit,(int __c));
int _EXFUN(tolower, (int __c));
int _EXFUN(toupper, (int __c));

#if !defined(__STRICT_ANSI__) || defined(__cplusplus) || __STDC_VERSION__ >= 199901L
int _EXFUN(isblank, (int __c));
#endif

#ifndef __STRICT_ANSI__
int _EXFUN(isascii, (int __c));
int _EXFUN(toascii, (int __c));
#define _tolower(__c) ((unsigned char)(__c) - 'A' + 'a')
#define _toupper(__c) ((unsigned char)(__c) - 'a' + 'A')
#endif

#define	_U	01
#define	_L	02
#define	_N	04
#define	_S	010
#define _P	020
#define _C	040
#define _X	0100
#define	_B	0200

#ifndef _MB_CAPABLE
_CONST
#endif
extern	__IMPORT char	* _CONST __ctype_ptr__;

#ifndef __cplusplus
/* These macros are intentionally written in a manner that will trigger
   a gcc -Wall warning if the user mistakenly passes a 'char' instead
   of an int containing an 'unsigned char'.  Note that the sizeof will
   always be 1, which is what we want for mapping EOF to __ctype_ptr__[0];
   the use of a raw index inside the sizeof triggers the gcc warning if
   __c was of type char, and sizeof masks side effects of the extra __c.
   Meanwhile, the real index to __ctype_ptr__+1 must be cast to int,
   since isalpha(0x100000001LL) must equal isalpha(1), rather than being
   an out-of-bounds reference on a 64-bit machine.  */
#define __ctype_lookup(__c) ((__ctype_ptr__+sizeof(""[__c]))[(int)(__c)])

#define	isalpha(__c)	(__ctype_lookup(__c)&(_U|_L))
#define	isupper(__c)	((__ctype_lookup(__c)&(_U|_L))==_U)
#define	islower(__c)	((__ctype_lookup(__c)&(_U|_L))==_L)
#define	isdigit(__c)	(__ctype_lookup(__c)&_N)
#define	isxdigit(__c)	(__ctype_lookup(__c)&(_X|_N))
#define	isspace(__c)	(__ctype_lookup(__c)&_S)
#define ispunct(__c)	(__ctype_lookup(__c)&_P)
#define isalnum(__c)	(__ctype_lookup(__c)&(_U|_L|_N))
#define isprint(__c)	(__ctype_lookup(__c)&(_P|_U|_L|_N|_B))
#define	isgraph(__c)	(__ctype_lookup(__c)&(_P|_U|_L|_N))
#define iscntrl(__c)	(__ctype_lookup(__c)&_C)

#if defined(__GNUC__) && \
    (!defined(__STRICT_ANSI__) || __STDC_VERSION__ >= 199901L)
#define isblank(__c) \
  __extension__ ({ __typeof__ (__c) __x = (__c);		\
        (__ctype_lookup(__x)&_B) || (int) (__x) == '\t';})
#endif


/* Non-gcc versions will get the library versions, and will be
   slightly slower.  These macros are not NLS-aware so they are
   disabled if the system supports the extended character sets. */
# if defined(__GNUC__)
#  if !defined (_MB_EXTENDED_CHARSETS_ISO) && !defined (_MB_EXTENDED_CHARSETS_WINDOWS)
#   define toupper(__c) \
  __extension__ ({ __typeof__ (__c) __x = (__c);	\
      islower (__x) ? (int) __x - 'a' + 'A' : (int) __x;})
#   define tolower(__c) \
  __extension__ ({ __typeof__ (__c) __x = (__c);	\
      isupper (__x) ? (int) __x - 'A' + 'a' : (int) __x;})
#  else /* _MB_EXTENDED_CHARSETS* */
/* Allow a gcc warning if the user passed 'char', but defer to the
   function.  */
#   define toupper(__c) \
  __extension__ ({ __typeof__ (__c) __x = (__c);	\
      (void) __ctype_ptr__[__x]; (toupper) (__x);})
#   define tolower(__c) \
  __extension__ ({ __typeof__ (__c) __x = (__c);	\
      (void) __ctype_ptr__[__x]; (tolower) (__x);})
#  endif /* _MB_EXTENDED_CHARSETS* */
# endif /* __GNUC__ */
#endif /* !__cplusplus */

#ifndef __STRICT_ANSI__
#define isascii(__c)	((unsigned)(__c)<=0177)
#define toascii(__c)	((__c)&0177)
#endif

/* For C++ backward-compatibility only.  */
extern	__IMPORT _CONST char	_ctype_[];

_END_STD_C

#endif /* _CTYPE_H_ */