NAME
wcsrtombs - convert a wide-character string to a character string
(restartable)
SYNOPSIS
#include <wchar.h>
size_t wcsrtombs(char *restrict dst, const wchar_t **restrict src,
size_t len, mbstate_t *restrict ps);
DESCRIPTION
The wcsrtombs() function shall convert a sequence of wide characters
from the array indirectly pointed to by src into a sequence of
corresponding characters, beginning in the conversion state described
by the object pointed to by ps. If dst is not a null pointer, the
converted characters shall then be stored into the array pointed to by
dst. Conversion continues up to and including a terminating null wide
character, which shall also be stored. Conversion shall stop earlier in
the following cases:
* When a code is reached that does not correspond to a valid character
* When the next character would exceed the limit of len total bytes to
be stored in the array pointed to by dst (and dst is not a null
pointer)
Each conversion shall take place as if by a call to the wcrtomb()
function.
If dst is not a null pointer, the pointer object pointed to by src
shall be assigned either a null pointer (if conversion stopped due to
reaching a terminating null wide character) or the address just past
the last wide character converted (if any). If conversion stopped due
to reaching a terminating null wide character, the resulting state
described shall be the initial conversion state.
If ps is a null pointer, the wcsrtombs() function shall use its own
internal mbstate_t object, which is initialized at program start-up to
the initial conversion state. Otherwise, the mbstate_t object pointed
to by ps shall be used to completely describe the current 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 wcsrtombs().
If the application uses any of the _POSIX_THREAD_SAFE_FUNCTIONS or
_POSIX_THREADS functions, the application shall ensure that the
wcsrtombs() 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
If conversion stops because a code is reached that does not correspond
to a valid character, an encoding error occurs. In this case, the
wcsrtombs() function shall store the value of the macro [EILSEQ] in
errno and return (size_t)-1; the conversion state is undefined.
Otherwise, it shall return the number of bytes in the resulting
character sequence, not including the terminating null (if any).
ERRORS
The wcsrtombs() function may fail if:
EINVAL ps points to an object that contains an invalid conversion
state.
EILSEQ A wide-character code does not correspond to a valid character.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
mbsinit() , wcrtomb() , 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 original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .