MBRTOWC(3) | Library Functions Manual | MBRTOWC(3) |
mbrtowc
—
#include <wchar.h>
size_t
mbrtowc
(wchar_t
* restrict pwc, const
char * restrict s, size_t
n, mbstate_t * restrict
ps);
mbrtowc
() usually converts the multibyte character
pointed to by s to a wide character, and stores the wide
character to the wchar_t object pointed to by pwc if
pwc is non-NULL
and
s points to a valid character. The conversion happens in
accordance with, and changes the conversion state described in the mbstate_t
object pointed to by ps. This function may examine at
most n bytes of the array beginning from
s.
If s points to a valid character and the
character corresponds to a nul wide character, then the
mbrtowc
() places the mbstate_t object pointed to by
ps to an initial conversion state.
Unlike mbtowc(3),
the mbrtowc
() may accept the byte sequence pointed
to by s not forming a complete multibyte character but
which may be part of a valid character. In this case, this function will
accept all such bytes and save them into the conversion state object pointed
to by ps. They will be used at subsequent calls of
this function to restart the conversion suspended.
The behaviour of mbrtowc
() is affected by
the LC_CTYPE
category of the current locale.
These are the special cases:
mbrtowc
() sets the conversion state object pointed
to by ps to an initial state and always returns 0.
Unlike mbtowc(3), the value
returned does not indicate whether the current encoding of the locale is
state-dependent.
In this case, mbrtowc
() ignores
pwc and n, and is equivalent
to the following call:
mbrtowc(NULL, "", 1, ps);
mbrtowc
() uses its own internal state object to
keep the conversion state, instead of ps mentioned
in this manual page.
Calling any other functions in Standard
C Library (libc, -lc) never changes the internal state of
mbrtowc
(), which is initialized at startup time
of the program.
mbrtowc
() returns:
mbrtowc
() returns the number of bytes in the
character.MB_CUR_MAX
,
this case can only occur if the array pointed to by
s contains a redundant shift sequence.mbrtowc
() sets errno to
indicate the error.mbrtowc
() may cause an error in the following case:
mbrtowc
() function conforms to
ISO/IEC 9899/AMD1:1995 (“ISO C90, Amendment
1”). The restrict qualifier is added at ISO/IEC
9899:1999 (“ISO C99”).
February 4, 2002 | NetBSD 9.2 |