MBSRTOWCS(3) OpenBSD Programmer's Manual MBSRTOWCS(3)NAMEmbsrtowcs - converts a multibyte character string to a wide-character
string (restartable)
SYNOPSIS
#include <wchar.h>
size_t
mbsrtowcs(wchar_t * restrict pwcs, const char ** restrict s, size_t
n, mbstate_t * restrict ps);
DESCRIPTION
The mbsrtowcs() converts the multibyte character string indirectly
pointed to by s to the corresponding wide-character string, and stores it
in the array pointed to by pwcs. The conversion stops due to the
following reasons:
o The conversion reaches a null byte. In this case, the null byte is
also converted.
o The mbsrtowcs() has already stored n wide characters.
o The conversion encounters an invalid character.
Each character is converted as if mbrtowc(3) is continuously called.
After conversion, if pwcs is not a NULL pointer, the pointer object
pointed to by s is a NULL pointer (if the conversion is stopped due to
reaching a null byte) or the first byte of the character just after the
last character converted.
If pwcs is not a null pointer and the conversion is stopped due to
reaching a null byte, the mbsrtowcs() places the state object pointed to
by ps to an initial state after the conversion has taken place.
The behaviour of the mbsrtowcs() is affected by the LC_CTYPE category of
the current locale.
These are the special cases:
s == NULL || *s == NULL
Undefined (may cause the program to crash).
pwcs == NULL The conversion has taken place, but the resultant wide-
character string was discarded. In this case, the pointer
object pointed to by s is not modified and n is ignored.
ps == NULL The mbsrtowcs() uses its own internal state object to keep
the conversion state, instead of ps mentioned in this
manual page.
Calling any other functions in libc never change the
internal state of mbsrtowcs(), which is initialized at
startup time of the program.
RETURN VALUESmbsrtowcs() returns:
0 or positive
The value returned is the number of elements stored in the
array pointed to by pwcs, except for a terminating null
wide character (if any). If pwcs is not null and the value
returned is equal to n, the wide-character string pointed
to by pwcs is not null terminated. If pwcs is a null
pointer, the value returned is the number of elements to
contain the whole string converted, except for a
terminating null wide character.
(size_t)-1 The array indirectly pointed to by s contains a byte
sequence forming invalid character. In this case,
mbsrtowcs() sets errno to indicate the error.
ERRORSmbsrtowcs() may cause an error in the following cases:
[EILSEQ] The pointer pointed to by s points to an invalid or
incomplete multibyte character.
[EINVAL] ps points to an invalid or uninitialized mbstate_t object.
SEE ALSOmbrtowc(3), mbstowcs(3), setlocale(3)STANDARDS
The mbsrtowcs() function conforms to ISO/IEC 9899/AMD1:1995 (``ISO C90,
Amendment 1''). The restrict qualifier is added at ISO/IEC 9899/1999
``(ISO C99)''.
OpenBSD 4.9 September 10, 2010 OpenBSD 4.9
