WCRTOMB(P) WCRTOMB(P)
NAME
wcrtomb - convert a wide-character code to a character (restartable)
SYNOPSIS
#include <stdio.h>
size_t wcrtomb(char *restrict s, wchar_t wc, mbstate_t *restrict ps);
DESCRIPTION
If s is a null pointer, the wcrtomb() function shall be equivalent to the call:
wcrtomb(buf, L'\0', ps)
where buf is an internal buffer.
If s is not a null pointer, the wcrtomb() function shall determine the number of bytes
needed to represent the character that corresponds to the wide character given by wc
(including any shift sequences), and store the resulting bytes in the array whose first
element is pointed to by s. At most {MB_CUR_MAX} bytes are stored. If wc is a null wide
character, a null byte shall be stored, preceded by any shift sequence needed to restore
the initial shift state. The resulting state described shall be the initial conversion
state.
If ps is a null pointer, the wcrtomb() function shall use its own internal mbstate_t
object, which is initialized at program start-up to the initial conversion state. Other-
wise, the mbstate_t object pointed to by ps shall be used to completely describe the cur-
rent conversion state of the associated character sequence. The implementation shall
behave as if no function defined in this volume of IEEE Std 1003.1-2001 calls wcrtomb().
If the application uses any of the _POSIX_THREAD_SAFE_FUNCTIONS or _POSIX_THREADS func-
tions, the application shall ensure that the wcrtomb() function is called with a non-NULL
ps argument.
The behavior of this function shall be affected by the LC_CTYPE category of the current
locale.
RETURN VALUE
The wcrtomb() function shall return the number of bytes stored in the array object
(including any shift sequences). When wc is not a valid wide character, an encoding error
shall occur. In this case, the function shall store the value of the macro [EILSEQ] in
errno and shall return (size_t)-1; the conversion state shall be undefined.
ERRORS
The wcrtomb() function may fail if:
EINVAL ps points to an object that contains an invalid conversion state.
EILSEQ Invalid wide-character code is detected.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
mbsinit() , the Base Definitions volume of IEEE Std 1003.1-2001, <wchar.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std
1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System
Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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 orig-
inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .
POSIX 2003 WCRTOMB(P)
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