WCSRTOMBS(3) BSD Library Functions Manual WCSRTOMBS(3)
wcsrtombs -- converts a wide-character string to a multibyte character string (restartable)
Standard C Library (libc, -lc)
wcsrtombs(char * restrict s, const wchar_t ** restrict pwcs, size_t n,
mbstate_t * restrict ps);
The wcsrtombs() converts the nul-terminated wide-character string indirectly pointed to by
pwcs to the corresponding multibyte character string, and stores it in the array pointed to
by s. The conversion stops due to the following reasons:
o The conversion reaches a nul wide character. In this case, the nul wide character is
o The wcsrtombs() has already stored n bytes in the array pointed to by s.
o The conversion encounters an invalid character.
Each character will be converted as if wcrtomb(3) is continuously called, except the inter-
nal state of wcrtomb(3) will not be affected.
After conversion, if s is not a null pointer, the pointer object pointed to by pwcs is a
null pointer (if the conversion is stopped due to reaching a nul wide character) or the
first byte of the character just after the last character converted.
If s is not a null pointer and the conversion is stopped due to reaching a nul wide charac-
ter, wcsrtombs() places the state object pointed to by ps to an initial state after the con-
version is taken place.
The behaviour of wcsrtombs() is affected by the LC_CTYPE category of the current locale.
These are the special cases:
s == NULL wcsrtombs() returns the number of bytes to store the whole multibyte character
string corresponding to the wide-character string pointed to by pwcs, not
including the terminating nul byte. In this case, n is ignored.
pwcs == NULL || *pwcs == NULL
Undefined (may cause the program to crash).
ps == NULL wcsrtombs() uses its own internal state object to keep the conversion state,
instead of ps mentioned in this manual page.
Calling any other functions in Standard C Library (libc, -lc) never changes
the internal state of wcsrtombs(), which is initialized at startup time of the
0 or positive
Number of bytes stored in the array pointed to by s, except for a nul byte.
There are no cases that the value returned is greater than n (unless s is a
null pointer). If the return value is equal to n, the string pointed to by s
will not be nul-terminated.
(size_t)-1 pwcs points to a string containing an invalid wide character. The wcsrtombs()
also sets errno to indicate the error.
wcsrtombs() may cause an error in the following case:
[EILSEQ] pwcs points to a string containing an invalid wide character.
setlocale(3), wcrtomb(3), wcstombs(3)
The wcsrtombs() function conforms to ANSI X3.159-1989 (``ANSI C89''). The restrict quali-
fier is added at ISO/IEC 9899:1999 (``ISO C99'').
BSD August 8, 2006 BSD