mbtowc - convert a character to a wide-character code
int mbtowc(wchar_t *pwc, const char *s, size_t n);
If s is not a null pointer, mbtowc() determines the number
of the bytes that constitute the character pointed to by s.
It then determines the wide-character code for the value of
type wchar_t that corresponds to that character. (The value
of the wide-character code corresponding to the null byte is
0.) If the character is valid and pwc is not a null pointer,
mbtowc() stores the wide-character code in the object
pointed to by pwc.
A call with s as a null pointer causes this function to
return 0. The behavior of this function is affected by the
LC_CTYPE category of the current locale. At most n bytes of
the array pointed to by s will be examined.
If s is a null pointer, mbtowc() returns 0. If s is not a
null pointer, mbtowc() returns 0 (if s points to the null
byte), the number of bytes that constitute the converted
character (if the next n or fewer bytes form a valid charac-
ter), or -1 and may set errno to indicate the error (if
they do not form a valid character).
In no case will the value returned be greater than n or the
value of the MB_CUR_MAX macro.
The mbtowc() function may fail if:
Invalid character sequence is detected.
The mbtowc() function can be used safely in multithreaded
applications, as long as setlocale(3C) is not being called
to change the locale.
See attributes(5) for descriptions of the following attri-
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| MT-Level | MT-Safe with exceptions |
| CSI | Enabled |
mblen(3C), mbstowcs(3C), setlocale(3C), wcstombs(3C),
Man(1) output converted with