Originální popis anglicky:
wcrtomb - convert a wide character to a multibyte sequence
Návod, kniha: Linux Programmer's Manual
#include <wchar.h>
size_t wcrtomb(char *s, wchar_t wc, mbstate_t *ps);
The main case for this function is when
s is not NULL and
wc is
not L'\0'. In this case, the
wcrtomb function converts the wide
character
wc to its multibyte representation and stores it at the
beginning of the character array pointed to by
s. It updates the shift
state
*ps, and returns the length of said multibyte representation,
i.e. the number of bytes written at
s.
A different case is when
s is not NULL but
wc is L'\0'. In this
case the
wcrtomb function stores at the character array pointed to by
s the shift sequence needed to bring
*ps back to the initial
state, followed by a '\0' byte. It updates the shift state
*ps (i.e.
brings it into the initial state), and returns the length of the shift
sequence plus one, i.e. the number of bytes written at
s.
A third case is when
s is NULL. In this case
wc is ignored, and
the function effectively returns wcrtomb(buf,L'\0',
ps) where buf is an
internal anonymous buffer.
In all of the above cases, if
ps is a NULL pointer, a static anonymous
state only known to the wcrtomb function is used instead.
The
wcrtomb function returns the number of bytes that have been or would
have been written to the byte array at
s. If
wc can not be
represented as a multibyte sequence (according to the current locale),
(size_t)(-1) is returned, and
errno set to
EILSEQ.
ISO/ANSI C, UNIX98
wcsrtombs(3)
The behaviour of
wcrtomb depends on the LC_CTYPE category of the current
locale.
Passing NULL as
ps is not multi-thread safe.
