include/ctype.h

   1 /* The <ctype.h> header file defines some macros used to identify characters.
   2  * It works by using a table stored in chartab.c. When a character is presented
   3  * to one of these macros, the character is used as an index into the table
   4  * (__ctype) to retrieve a byte.  The relevant bit is then extracted.
   5  */
   6
   7 #ifndef _CTYPE_H
   8 #define _CTYPE_H
   9
  10 #ifndef _ANSI_H
  11 #include <ansi.h>
  12 #endif
  13
  14 extern char     __ctype[];      /* property array defined in chartab.c */
  15
  16 #define _U              0x01    /* this bit is for upper-case letters [A-Z] */
  17 #define _L              0x02    /* this bit is for lower-case letters [a-z] */
  18 #define _N              0x04    /* this bit is for numbers [0-9] */
  19 #define _S              0x08    /* this bit is for white space \t \n \f etc */
  20 #define _P              0x10    /* this bit is for punctuation characters */
  21 #define _C              0x20    /* this bit is for control characters */
  22 #define _X              0x40    /* this bit is for hex digits [a-f] and [A-F]*/
  23
  24 /* Function Prototypes (have to go before the macros). */
  25 _PROTOTYPE( int isalnum, (int  _c)  );  /* alphanumeric [a-z], [A-Z], [0-9] */
  26 _PROTOTYPE( int isalpha, (int  _c)  );  /* alphabetic */
  27 _PROTOTYPE( int iscntrl, (int  _c)  );  /* control characters */
  28 _PROTOTYPE( int isdigit, (int  _c)  );  /* digit [0-9] */
  29 _PROTOTYPE( int isgraph, (int  _c)  );  /* graphic character */
  30 _PROTOTYPE( int islower, (int  _c)  );  /* lower-case letter [a-z] */
  31 _PROTOTYPE( int isprint, (int  _c)  );  /* printable character */
  32 _PROTOTYPE( int ispunct, (int  _c)  );  /* punctuation mark */
  33 _PROTOTYPE( int isspace, (int  _c)  );  /* white space sp, \f, \n, \r, \t, \v*/
  34 _PROTOTYPE( int isupper, (int  _c)  );  /* upper-case letter [A-Z] */
  35 _PROTOTYPE( int isxdigit,(int  _c)  );  /* hex digit [0-9], [a-f], [A-F] */
  36 _PROTOTYPE( int tolower, (int  _c)  );  /* convert to lower-case */
  37 _PROTOTYPE( int toupper, (int  _c)  );  /* convert to upper-case */
  38 _PROTOTYPE( int toascii, (int  _c)  );  /* convert to 7-bit ASCII */
  39
  40 /* Macros for identifying character classes. */
  41 #define isalnum(c)      ((__ctype+1)[c]&(_U|_L|_N))
  42 #define isalpha(c)      ((__ctype+1)[c]&(_U|_L))
  43 #define iscntrl(c)      ((__ctype+1)[c]&_C)
  44 #define isgraph(c)      ((__ctype+1)[c]&(_P|_U|_L|_N))
  45 #define ispunct(c)      ((__ctype+1)[c]&_P)
  46 #define isspace(c)      ((__ctype+1)[c]&_S)
  47 #define isxdigit(c)     ((__ctype+1)[c]&(_N|_X))
  48
  49 #define isdigit(c)      ((unsigned) ((c)-'0') < 10)
  50 #define islower(c)      ((unsigned) ((c)-'a') < 26)
  51 #define isupper(c)      ((unsigned) ((c)-'A') < 26)
  52 #define isprint(c)      ((unsigned) ((c)-' ') < 95)
  53 #define isascii(c)      ((unsigned) (c) < 128)
  54
  55 #define toascii(c)      ((c) & 0x7f)
  56
  57 #endif /* _CTYPE_H */