ctype(3)						     Library Functions Manual							  ctype(3)

Name
       isalpha,  isupper,  islower,  isdigit,  isxdigit,  isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isascii - character classification
       macros

Syntax
       #include <ctype.h>

       int isalpha (c)

       int c;

Description
       These macros classify character-coded integer values according to the rules of the coded character set (codeset)  identified  by  the  last
       successful call to category All macros return non-zero for true and zero for false.

       If  category  has  not been called successfully, or if character classification information is not available for a supported language, then
       characters are classified according to the rules of the ASCII 7-bit coded character set, returning 0 for values above octal 0177.

       The macro provides a result for all integer values.  The rest provide a result for EOF and values in the character  range  of  the  codeset
       identified by the last successful call to category

       c	      is a letter

       c	      is an uppercase letter

       c	      is a lowercase letter

       c	      is a digit

       c	      is a hexadecimal digit, by default [0-9], [A-F], or [a-f]

       c	      is an alphanumeric character

       c	      is a space, tab, carriage return, new line, or form feed

       c	      is a punctuation character (neither control, alphanumeric, nor space)

       c	      is a printing character, by default code 040(8) (space) through 0176 (tilde)

       c	      is a printing character, like except false for space

       c	      is a delete character(0177) or ordinary control character (less than 040) except for space characters

       c	      is an ASCII character, code less than 0200

   International Environment
       LC_CTYPE       If this environment variable is set and valid, uses the international language database named in the definition to determine
		      character classification rules.

       LANG	      If this environment variable is set and valid, uses the international language database named in the definition to determine
		      the character classification rules. If is defined, that definition supercedes the definition of

See Also
       conv(3), setlocale(3), stdio(3s), environ(5int), ascii(7)
       Guide to Developing International Software

																	  ctype(3)