ctype.h(0P)		   POSIX Programmer's Manual		   ctype.h(0P)

PROLOG
       This manual page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the corresponding
       Linux manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.

NAME
       ctype.h — character types

SYNOPSIS
       #include <ctype.h>

DESCRIPTION
       Some of the functionality described on this reference page extends the
       ISO C standard. Applications shall define the appropriate feature test
       macro (see the System Interfaces volume of POSIX.1‐2017, Section 2.2,
       The Compilation Environment) to enable the visibility of these symbols
       in this header.

       The <ctype.h> header shall define the locale_t type as described in
       <locale.h>, representing a locale object.

       The following shall be declared as functions and may also be defined as
       macros. Function prototypes shall be provided for use with ISO C
       standard compilers.


	   int	 isalnum(int);
	   int	 isalnum_l(int, locale_t);
	   int	 isalpha(int);
	   int	 isalpha_l(int, locale_t);
	   int	 isascii(int);
	   int	 isblank(int);
	   int	 isblank_l(int, locale_t);
	   int	 iscntrl(int);
	   int	 iscntrl_l(int, locale_t);
	   int	 isdigit(int);
	   int	 isdigit_l(int, locale_t);
	   int	 isgraph(int);
	   int	 isgraph_l(int, locale_t);
	   int	 islower(int);
	   int	 islower_l(int, locale_t);
	   int	 isprint(int);
	   int	 isprint_l(int, locale_t);
	   int	 ispunct(int);
	   int	 ispunct_l(int, locale_t);
	   int	 isspace(int);
	   int	 isspace_l(int, locale_t);
	   int	 isupper(int);
	   int	 isupper_l(int, locale_t);
	   int	 isxdigit(int);
	   int	 isxdigit_l(int, locale_t);
	   int	 toascii(int);
	   int	 tolower(int);
	   int	 tolower_l(int, locale_t);
	   int	 toupper(int);
	   int	 toupper_l(int, locale_t);

       The <ctype.h> header shall define the following as macros:


	   int	 _toupper(int);
	   int	 _tolower(int);

       The following sections are informative.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       <locale.h>

       The System Interfaces volume of POSIX.1‐2017, Section 2.2, The
       Compilation Environment, isalnum(), isalpha(), isascii(), isblank(),
       iscntrl(), isdigit(), isgraph(), islower(), isprint(), ispunct(),
       isspace(), isupper(), isxdigit(), mblen(), mbstowcs(), mbtowc(),
       setlocale(), toascii(), tolower(), _tolower(), toupper(), _toupper(),
       wcstombs(), wctomb()

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  In the event of any discrepancy between this version and the
       original IEEE and The Open Group Standard, the original IEEE and The
       Open Group Standard is the referee document. The original Standard can
       be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group		     2017			   ctype.h(0P)