ctype.h

linux内核

/*
 * ctype.h
 *
 * This assumes ISO 8859-1, being a reasonable superset of ASCII.
 */

#ifndef _CTYPE_H
#define _CTYPE_H

#ifndef __CTYPE_NO_INLINE
# define __ctype_inline extern __inline__
#else
# define __ctype_inline
#endif

/*
 * This relies on the following definitions:
 *
 * cntrl = !print
 * alpha = upper|lower
 * graph = punct|alpha|digit
 * blank = '\t' || ' ' (per POSIX requirement)
 */
enum {
  __ctype_upper  = (1 << 0),
  __ctype_lower  = (1 << 1),
  __ctype_digit  = (1 << 2),
  __ctype_xdigit = (1 << 3),
  __ctype_space  = (1 << 4),
  __ctype_print  = (1 << 5),
  __ctype_punct  = (1 << 6),
  __ctype_cntrl  = (1 << 7),
};

extern const unsigned char __ctypes[];

__ctype_inline int isalnum(int __c)
{
  return __ctypes[__c+1] &
    (__ctype_upper|__ctype_lower|__ctype_digit);
}

__ctype_inline int isalpha(int __c)
{
  return __ctypes[__c+1] &
    (__ctype_upper|__ctype_lower);
}

__ctype_inline int isascii(int __c)
{
  return !(__c & ~0x7f);
}

__ctype_inline int isblank(int __c)
{
  return (__c == '\t') || (__c == ' ');
}

__ctype_inline int iscntrl(int __c)
{
  return __ctypes[__c+1] & __ctype_cntrl;
}

__ctype_inline int isdigit(int __c)
{
  return ((unsigned)__c - '0') <= 9;
}

__ctype_inline int isgraph(int __c)
{
  return __ctypes[__c+1] &
    (__ctype_upper|__ctype_lower|__ctype_digit|__ctype_punct);
}

__ctype_inline int islower(int __c)
{
  return __ctypes[__c+1] & __ctype_lower;
}

__ctype_inline int isprint(int __c)
{
  return __ctypes[__c+1] & __ctype_print;
}

__ctype_inline int ispunct(int __c)
{
  return __ctypes[__c+1] & __ctype_punct;
}

__ctype_inline int isspace(int __c)
{
  return __ctypes[__c+1] & __ctype_space;
}

__ctype_inline int isupper(int __c)
{
  return __ctypes[__c+1] & __ctype_upper;
}

__ctype_inline int isxdigit(int __c)
{
  return __ctypes[__c+1] & __ctype_xdigit;
}

/* Note: this is decimal, not hex, to avoid accidental promotion to unsigned */
#define _toupper(__c) ((__c) & ~32)
#define _tolower(__c) ((__c) | 32)

__ctype_inline int toupper(int __c)
{
  return islower(__c) ? _toupper(__c) : __c;
}

__ctype_inline int tolower(int __c)
{
  return isupper(__c) ? _tolower(__c) : __c;
}

#endif /* _CTYPE_H */