ctype(3) [mojave man page]

CTYPE(3)						   BSD Library Functions Manual 						  CTYPE(3)

NAME

     digittoint, isalnum, isalpha, isascii, isblank, iscntrl, isdigit, isgraph, ishexnumber, isideogram, islower, isnumber, isphonogram, isprint,
     ispunct, isrune, isspace, isspecial, isupper, isxdigit, toascii, tolower, toupper -- character classification macros

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <ctype.h>

     int
     digittoint(int c);

     int
     isalnum(int c);

     int
     isalpha(int c);

     int
     isascii(int c);

     int
     iscntrl(int c);

     int
     isdigit(int c);

     int
     isgraph(int c);

     int
     ishexnumber(int c);

     int
     isideogram(int c);

     int
     islower(int c);

     int
     isnumber(int c);

     int
     isphonogram(int c);

     int
     isspecial(int c);

     int
     isprint(int c);

     int
     ispunct(int c);

     int
     isrune(int c);

     int
     isspace(int c);

     int
     isupper(int c);

     int
     isxdigit(int c);

     int
     toascii(int c);

     int
     tolower(int c);

     int
     toupper(int c);

DESCRIPTION

     The above functions perform character tests and conversions on the integer c.  They are available as macros, defined in the include file
     <ctype.h>, or as true functions in the C library.	See the specific manual pages for more information.

     Extended locale versions of these functions are documented in ctype_l(3).	See xlocale(3) for more information.

SEE ALSO

     digittoint(3), isalnum(3), isalpha(3), isascii(3), isblank(3), iscntrl(3), isdigit(3), isgraph(3), isideogram(3), islower(3), isphonogram(3),
     isprint(3), ispunct(3), isrune(3), isspace(3), isspecial(3), isupper(3), isxdigit(3), toascii(3), tolower(3), toupper(3), wctype(3),
     ascii(7), ctype_l(3)

STANDARDS

     These functions, except for digittoint(), isascii(), ishexnumber(), isideogram(), isnumber(), isphonogram(), isrune(), isspecial() and
     toascii(), conform to ISO/IEC 9899:1990 (``ISO C90'').

BSD
								  March 30, 2004							       BSD

CTYPE(3)						   BSD Library Functions Manual 						  CTYPE(3)

NAME

     isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isblank, toupper, tolower, -- character
     classification and mapping functions

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <ctype.h>

     isalpha(int c);

     isupper(int c);

     islower(int c);

     isdigit(int c);

     isxdigit(int c);

     isalnum(int c);

     isspace(int c);

     ispunct(int c);

     isprint(int c);

     isgraph(int c);

     iscntrl(int c);

     isblank(int c);

     toupper(int c);

     tolower(int c);

DESCRIPTION

     The above functions perform character tests and conversions on the integer c.

     See the specific manual pages for information about the test or conversion performed by each function.

EXAMPLES

     To print an upper-case version of a string to stdout, the following code can be used:

	   const char *s = "xyz";

	   while (*s != '') {
	       putchar(toupper((int)(unsigned char)*s));
	       s++;
	   }

SEE ALSO

     isalnum(3), isalpha(3), isblank(3), iscntrl(3), isdigit(3), isgraph(3), islower(3), isprint(3), ispunct(3), isspace(3), isupper(3),
     isxdigit(3), tolower(3), toupper(3), ascii(7)

STANDARDS

     These functions, with the exception of isblank(), conform to ANSI X3.159-1989 (``ANSI C89'').  All described functions, including isblank(),
     also conform to IEEE Std 1003.1-2001 (``POSIX.1'').

CAVEATS

     The first argument of these functions is of type int, but only a very restricted subset of values are actually valid.  The argument must
     either be the value of the macro EOF (which has a negative value), or must be a non-negative value within the range representable as unsigned
     char.  Passing invalid values leads to undefined behavior.

     Values of type int that were returned by getc(3), fgetc(3), and similar functions or macros are already in the correct range, and may be
     safely passed to these ctype functions without any casts.

     Values of type char or signed char must first be cast to unsigned char, to ensure that the values are within the correct range.  The result
     should then be cast to int to avoid warnings from some compilers.	Casting a negative-valued char or signed char directly to int will produce
     a negative-valued int, which will be outside the range of allowed values (unless it happens to be equal to EOF, but even that would not give
     the desired result).

BSD
								    May 6, 2010 							       BSD