The main case for this function is when s is not NULL and pwc is
In this case, the
function inspects at most n
bytes of the multibyte string starting at s,
extracts the next complete
multibyte character, converts it to a wide character and stores it at
It updates an internal shift state only known to the mbtowc
If s does not point to a '\0' byte, it returns the number
of bytes that were consumed from s, otherwise it returns 0.
If the n bytes starting at s do not contain a complete multibyte
character, or if they contain an invalid multibyte sequence,
This can happen even if n >= MB_CUR_MAX,
if the multibyte string contains redundant shift sequences.
A different case is when s is not NULL but pwc is NULL.
function behaves as above, except that it does not
store the converted wide character in memory.
A third case is when s is NULL.
In this case, pwc and n are
resets the shift state, only known to this function,
to the initial state, and
returns nonzero if the encoding has nontrivial shift state, or zero if the
encoding is stateless.
If s is not NULL, the
function returns the number of
consumed bytes starting at s, or 0 if s points to a null byte,
or -1 upon failure.
If s is NULL, the
returns nonzero if the encoding
has nontrivial shift state, or zero if the encoding is stateless.
The behavior of
depends on the
category of the
This function is not multithread safe.
a better interface to the same functionality.