Category : C Source Code
Archive   : E_C_STR.ZIP
Filename : CTYPES.H

/* File : ctypes.h
Author : Richard A. O'Keefe.
Updated: 26 April 1984
Purpose: Reimplement the UNIX ctype(3) library.

isaneol(c) means that c is a line terminating character.
isalnum, ispunct, isspace, and isaneol are defined on the
range -1..127, i.e. on ASCII U {EOF}, while all the other
macros are defined for any integer.

isodigit(c) checks for Octal digits.
isxdigit(c) checkx for heXadecimal digits.
*/

#define isdigit(c) ((unsigned)((c)-'0') < 10)
#define islower(c) ((unsigned)((c)-'a') < 26)
#define isupper(c) ((unsigned)((c)-'A') < 26)
#define isprint(c) ((unsigned)((c)-' ') < 95)
#define iscntrl(c) ((unsigned)((c)-' ') >= 95)
#define isascii(c) ((unsigned)(c) < 128)
#define isalpha(c) ((unsigned)(((c)|32)-'a') < 26)

extern char _c2type[];

#define isalnum(c) (_c2type[(c)+1] < 36)
#define ispunct(c) (_c2type[(c)+1] == 36)
#define isspace(c) (_c2type[(c)+1] > 37)
#define isaneol(c) (_c2type[(c)+1] > 38)

#define isxdigit(c) (_c2type[(c)+1] < 16)
#define isodigit(c) ((unsigned)((c)-'0') < 8)

/* The following "conversion" macros have been in some versions of UNIX
but are not in all. tocntrl is new. The original motivation for ^?
being a name for DEL was that (x)^64 mapped A..Z to ^A..^Z and also
? to DEL. The trouble is that this trick doesn't work for lower case
letters. The version given here is not mine. I wish it was. It has
the nice property that DEL is mapped to itself (so does EOF).
tolower(c) and toupper(c) are only defined when isalpha(c).
*/
#define tolower(c) ((c)|32)
#define toupper(c) ((c)&~32)
#define tocntrl(c) (((((c)+1)&~96)-1)&127)
#define toascii(c) ((c)&127)