size_t
mbstowcs(wchar_t * restrict pwcs, const char * restrict s, size_t n)
)
converts a nul-terminated multibyte character string pointed to by
s
to the corresponding wide character string and stores it in the array
pointed to by
pwcs.
This function may modify the first at most
n
elements of the array pointed to by
pwcs.
Each character will be converted as if
mbtowc(3)
is continuously called, except the internal state of
mbtowc(3)
will not be affected.
For state-dependent encoding,
mbstowcs()
implies the multibyte character string pointed to by
s
always begins with an initial state.
These are the special cases:
)
returns the number of elements to store the whole wide character string
corresponding to the multibyte character string pointed to by
s.
In this case,
n
is ignored.
)
returns:
pwcs.
There are no cases that the value returned is greater than
n
(unless
pwcs
is a null pointer) or the value of the
MB_CUR_MAX
macro.
If the return value is equal to
n,
the string pointed to by
pwcs
will not be nul-terminated.
s
points to a string containing an invalid or incomplete multibyte character.
The
mbstowcs()
also sets
errno
to indicate the error.
)
may cause an error in the following case:
EILSEQ]s
points to a string containing an invalid or incomplete multibyte character.
)
function conforms to
ANSI X3.159-1989 (``ANSI C89'') .
The restrict qualifier is added at
ISO/IEC 9899:1999 (``ISO C99'') .