NAME
mbrtowc, mbrtowc_l
— convert a character to a
wide-character code (restartable)
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include
<wchar.h>
size_t
mbrtowc(wchar_t *restrict pwc,
const char *restrict s, size_t
n, mbstate_t *restrict ps);
#include <wchar.h>
#include <xlocale.h>
size_t
mbrtowc_l(wchar_t *restrict pwc,
const char *restrict s, size_t
n, mbstate_t *restrict ps,
locale_t loc);
DESCRIPTION
The
mbrtowc()
function inspects at most n bytes, pointed to by
s, to determine the number of bytes needed to complete
the next multibyte character. If a character can be completed, and
pwc is not NULL, the wide
character which is represented by s is stored in the
wchar_t it points to.
If s is
NULL,
mbrtowc()
behaves as if pwc were NULL,
s were an empty string (""), and
n were 1.
The mbstate_t argument,
ps, is used to keep track of the shift state. If it is
NULL,
mbrtowc()
uses an internal, static mbstate_t object, which is
initialized to the initial conversion state at program startup.
While the
mbrtowc()
function uses the current locale, the
mbrtowc_l()
function may be passed a locale directly. See
xlocale(3) for more information.
RETURN VALUES
The mbrtowc() functions returns:
- 0
- The next n or fewer bytes represent the null wide
character (
L'\0'). - >0
- The next n or fewer bytes represent a valid
character,
mbrtowc() returns the number of bytes used to complete the multibyte character. - (size_t)-2
- The next n contribute to, but do not complete, a valid multibyte character sequence, and all n bytes have been processed.
- (size_t)-1
- An encoding error has occurred. The next n or fewer bytes do not contribute to a valid multibyte character.
ERRORS
The mbrtowc() function will fail if:
- [
EILSEQ] - An invalid multibyte sequence was detected.
- [
EINVAL] - The conversion state is invalid.
SEE ALSO
mbtowc(3), multibyte(3), setlocale(3), wcrtomb(3), xlocale(3)
STANDARDS
The mbrtowc() function conforms to
ISO/IEC 9899:1999
(“ISO C99”).