CTYPE(3C)		       Silicon Graphics			     CTYPE(3C)



NAME
     isdigit, isxdigit,	islower, isupper, isalpha, isalnum, isspace, iscntrl,
     ispunct, isprint, isgraph,	isascii, tolower, toupper, toascii, _tolower,
     _toupper, setchrclass - character handling

SYNOPSIS
     #include <ctype.h>

     int isdigit (int c);

     int isxdigit (int c);

     int islower (int c);

     int isupper (int c);

     int isalpha (int c);

     int isalnum (int c);

     int isspace (int c);

     int iscntrl (int c);

     int ispunct (int c);

     int isprint (int c);

     int isgraph (int c);

     int isascii (int c);

     int tolower (int c);

     int toupper (int c);

     int toascii (int c);

     int _tolower (int c);

     int _toupper (int c);

     int setchrclass (char *chrclass);

DESCRIPTION
     The character classification macros listed	below return nonzero for true,
     zero for false.  isascii is defined on all	integer	values;	the rest are
     defined on	valid members of the character set and on the single value EOF
     [see stdio(3S)] (guaranteed not to	be a character set member).






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CTYPE(3C)		       Silicon Graphics			     CTYPE(3C)



     isdigit	    tests for the digits 0 through 9.

     isxdigit	    tests for any character for	which isdigit is true or for
		    the	letters	a through f or A through F.

     islower	    tests for any lowercase letter as defined by the character
		    set.

     isupper	    tests for any uppercase letter as defined by the character
		    set.

     isalpha	    tests for any character for	which islower or isupper is
		    true and possibly any others as defined by the character
		    set.

     isalnum	    tests for any character for	which isalpha or isdigit is
		    true.

     isspace	    tests for a	space, horizontal-tab, carriage	return,
		    newline, vertical-tab, or form-feed.

     iscntrl	    tests for ``control	characters'' as	defined	by the
		    character set.

     ispunct	    tests for any character other than the ones	for which
		    isalnum, iscntrl, or isspace is true or space.

     isprint	    tests for a	space or any character for which isalnum or
		    ispunct is true or other ``printing	character'' as defined
		    by the character set.

     isgraph	    tests for any character for	which isprint is true, except
		    for	space.

     isascii	    tests for an ASCII character (a non-negative number	less
		    than 0200.)

     The conversion functions and macros translate a character from lowercase
     (uppercase) to uppercase (lowercase).

     tolower	    if the character is	one for	which isupper is true and
		    there a corresponding lowercase character, tolower returns
		    the	corresponding lowercase	character.  Otherwise, the
		    character is returned unchanged.

     toupper	    if the character is	one for	which islower is true and
		    there is a corresponding uppercase character, toupper
		    returns the	corresponding uppercase	character.  Otherwise,
		    the	character is returned unchanged.






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CTYPE(3C)		       Silicon Graphics			     CTYPE(3C)



     toascii	    turns off the bits that are	not part of the	ASCII
		    character set.

     _tolower	    returns the	lowercase representation of a character	for
		    which isupper is true, otherwise undefined.

     _toupper	    returns the	uppercase representation of a character	for
		    which islower is true, otherwise undefined.

     The conversion macros have	the same functionality of the functions	on
     valid input, but the macros are faster because they do not	do range
     checking.

     All the character classification macros and the conversion	functions and
     macros do a table lookup.

     setchrclass initializes the table used by these functions and macros to a
     specific character	classification set.  setchrclass uses the value	of its
     argument or the value of the environment variable CHRCLASS	as the name of
     the datafile containing the information for the desired character set.
     These datafiles are searched for in the special directory /lib/chrclass.

     If	chrclass is (char *)0, the value of the	environment variable CHRCLASS
     is	used. If CHRCLASS is not set or	is undefined, the table	retains	its
     default value.  The default value is the iso8859 character	set unless the
     executable	was compiled in	a strict ANSI mode (-ansi or -ansiposix)), in
     which case	the default character table is ascii.

FILES
     /lib/chrclass  - directory	containing the datafiles for setchrclass

SEE ALSO
     chrtbl(1M), stdio(3S), ascii(5), locale(3C), environ(5).

DIAGNOSTICS
     If	the argument to	any of the character handling macros is	not in the
     domain of the function, the result	is undefined.

     If	setchrclass does not successfully fill the table, the table will not
     change (initially ``ascii'') and -1 is returned.  If everything works,
     setchrclass returns 0.











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