ctype(3C)																 ctype(3C)

NAME

       ctype:  isalnum(), isalpha(), isascii(), isblank(), iscntrl(), isdigit(), isgraph(), islower(), isprint(), ispunct(), isspace(), isupper(),
       isxdigit() - classify characters according to type

SYNOPSIS

DESCRIPTION

       These functions classify character-coded integer values according to the rules of the coded character set identified by the last successful
       call to (see setlocale(3C)).  Each function is a predicate returning nonzero for true, zero for false.

       If  has	not been called successfully, characters are classified according to the rules of the default ASCII 7-bit coded character set (see
       setlocale(3C)).

       is defined on all integer values; the other functions are defined for the range (EOF) through

RETURN VALUE

       The functions return nonzero under the following circumstances; zero otherwise:

	      c 		  is an alphanumeric (letters or digits).

	      c 		  is a letter.

	      c 		  is any ASCII character code between 0 and 0177, inclusive.

	      c 		  is a blank character; that is, a space or a tab.

	      c 		  is a control character (in ASCII: character codes less than 040 and the delete character(0177)).

	      c 		  is a decimal digit (in ASCII: characters [0-9]).

	      c 		  is a visible character (in ASCII: printing characters, excluding the space character(040)).

	      c 		  is a lowercase letter.

	      c 		  is a printing character.

	      c 		  is a punctuation character (in ASCII: any printing character except the space character(040), digits, letters).

	      c 		  is a character that creates whitespace in displayed text (in ASCII: space, tab, carriage return, newline, verti-
				  cal tab, and formfeed).

	      c 		  is an uppercase letter.

	      c 		  is a hexadecimal digit (in ASCII: characters [0-9], [A-F] or [a-f]).

       If the argument to any of these functions is outside the domain of the function, the result is undefined.

EXTERNAL INFLUENCES

   Environment Variables
       The category determines the classification of character type.

   International Code Set Support
       Single-byte character code sets are supported.

WARNINGS

       These  functions  are  supplied	both as library functions and as macros defined in the header.	Normally, the macro versions are used.	To
       obtain the library function, either use a to remove the macro definition or, if compiling in ANSI-C mode,  enclose  the	function  name	in
       parenthesis or take its address.  The following example uses the library functions for and

AUTHOR

       was developed by IBM, OSF, and HP.

SEE ALSO

       setlocale(3C), ascii(5), thread_safety(5).

STANDARDS CONFORMANCE

																	 ctype(3C)