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ctype(3C)							     ctype(3C)

NAME
       ctype,  isalpha,	 isalnum, isascii, isblank, iscntrl, isdigit, islower,
       isprint,	isspace, isupper, ispunct, isgraph, isxdigit - character  han-
       dling

SYNOPSIS
       #include	<ctype.h>

       int isalpha(int c);

       int isalnum(int c);

       int isascii(int c);

       int isblank(int c);

       int iscntrl(int c);

       int isdigit(int c);

       int isgraph(int c);

       int islower(int c);

       int isprint(int c);

       int ispunct(int c);

       int isspace(int c);

       int isupper(int c);

       int isxdigit(int	c);

       These  macros classify character-coded integer values. Each is a	predi-
       cate returning non-zero for true, 0 for false. The  behavior  of	 these
       macros, except isascii(), is affected by	the current locale (see	setlo-
       cale(3C)). To modify the	behavior, change the LC_TYPE category in  set-
       locale(),  that is, setlocale(LC_CTYPE, newlocale).  In the "C" locale,
       or in a locale where character type information is not defined, charac-
       ters  are classified according to the rules of the US-ASCII 7-bit coded
       character set.

       The isascii() macro is defined on all integer values. The rest are  de-
       fined  only  where the argument is an int, the value of which is	repre-
       sentable	as an unsigned char, or	EOF, which is defined by the <stdio.h>
       header and represents end-of-file.

       Functions  exist	 for all the macros defined below. To get the function
       form, the macro name must be undefined (for example, #undef isdigit).

       For macros described with Default  and  Standard	 conforming  versions,
       standard-conforming behavior is provided	for standard-conforming	appli-
       cations	(see  standards(5))   and   for	  applications	 that	define
       __XPG4_CHAR_CLASS__ before including <ctype.h>.

   Default
       isalpha()       Tests  for  any	character  for	which isupper()	or is-
		       lower() is true.

   Standard conforming
       isalpha()       Tests for any character	for  which  isupper()  or  is-
		       lower()	is  true,  or any character that is one	of the
		       current locale-defined set of characters	for which none
		       of  iscntrl(),  isdigit(),  ispunct(),  or isspace() is
		       true. In	"C" locale, isalpha() returns  true  only  for
		       the  characters	for  which  isupper()  or islower() is
		       true.

       isalnum()       Tests for any character	for  which  isalpha()  or  is-
		       digit() is true (letter or digit).

       isascii()       Tests  for any ASCII character, code between 0 and 0177
		       inclusive.

       isblank()       Tests whether c is a character of class	blank  in  the
		       current locale. This macro/function is not available to
		       applications conforming to standards  prior  to	SUSv3.
		       See standards(5)

       iscntrl()       Tests  for  any ``control character'' as	defined	by the
		       character set.

       isdigit()       Tests for any decimal-digit character.

   Default
       isgraph()       Tests for any character for which ispunct(), isupper(),
		       islower(), and isdigit()	is true.

   Standard conforming
       isgraph()       Tests  for  any	character  for which isalnum() and is-
		       punct() are true, or any	character in the  current  lo-
		       cale-defined  "graph"  class  which  is neither a space
		       ("") nor	a character for	which iscntrl()	is true.

       islower()       Tests for any character that is a lower-case letter  or
		       is  one of the current locale-defined set of characters
		       for which none of iscntrl(), isdigit(), ispunct(), iss-
		       pace(),	or  isupper()  is true.	In the "C" locale, is-
		       lower() returns true only for the characters defined as
		       lower-case ASCII	characters.

   Default
       isprint()       Tests for any character for which ispunct(), isupper(),
		       islower(), isdigit(), and the space character  ("")  is
		       true.

   Standard conforming
       isprint()       Tests  for  any character for which iscntrl() is	false,
		       and isalnum(), isgraph(), ispunct(), the	space  charac-
		       ter  (""), and the characters in	the current locale-de-
		       fined "print" class are true.

       ispunct()       Tests for any printing character	 which	is  neither  a
		       space ("") nor a	character for which isalnum() or iscn-
		       trl() is	true.

       isspace()       Tests for any  space,  tab,  carriage-return,  newline,
		       vertical-tab or form-feed (standard white-space charac-
		       ters) or	for one	of the current locale-defined  set  of
		       characters  for	which  isalnum() is false.  In the "C"
		       locale, isspace() returns true only  for	 the  standard
		       white-space characters.

       isupper()       Tests for any character that is an upper-case letter or
		       is one of the current locale-defined set	of  characters
		       for which none of iscntrl(), isdigit(), ispunct(), iss-
		       pace(), or islower() is true. In	the "C"	locale,	 isup-
		       per()  returns  true only for the characters defined as
		       upper-case ASCII	characters.

   Default
       isxdigit()      Tests  for  any	hexadecimal-digit  character   ([0-9],
		       [A-F], or [a-f]).

   Standard conforming
       isxdigit()      Tests   for  any	 hexadecimal-digit  character  ([0-9],
		       [A-F], or [a-f] or the current locale-defined  sets  of
		       characters representing the hexadecimal digits 10 to 15
		       inclusive). In the "C" locale, only

		       0 1 2 3 4 5 6 7 8 9 A B C D E F a b c d e f

		       are included.

       If the argument to any of the character handling	macros is not  in  the
       domain  of  the function, the result is undefined. Otherwise, the macro
       or function returns non-zero if the classification is TRUE and 0	if the
       classification is FALSE.

USAGE
       These  macros or	functions can be used safely in	multithreaded applica-
       tions, as long as setlocale(3C) is not being called to change  the  lo-
       cale.

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE	TYPE	     |	    ATTRIBUTE VALUE	   |
       |CSI			     |Enabled			   |
       |Interface Stability	     |Standard			   |
       |MT-Level		     |MT-Safe with exceptions	   |
       +-----------------------------+-----------------------------+

       setlocale(3C), stdio(3C), ascii(5), environ(5), standards(5)

				  28 Jan 2005			     ctype(3C)

NAME | SYNOPSIS | USAGE

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