MBSRTOWCS(3)           FreeBSD Library Functions Manual           MBSRTOWCS(3)

NAME
     mbsrtowcs, mbsnrtowcs - convert a character string to a wide-character
     string (restartable)

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <wchar.h>

     size_t
     mbsrtowcs(wchar_t * restrict dst, const char ** restrict src, size_t len,
         mbstate_t * restrict ps);

     size_t
     mbsnrtowcs(wchar_t * restrict dst, const char ** restrict src,
         size_t nms, size_t len, mbstate_t * restrict ps);

DESCRIPTION
     The mbsrtowcs() function converts a sequence of multibyte characters
     pointed to indirectly by src into a sequence of corresponding wide
     characters and stores at most len of them in the wchar_t array pointed to
     by dst, until it encounters a terminating null character ('\0').

     If dst is NULL, no characters are stored.

     If dst is not NULL, the pointer pointed to by src is updated to point to
     the character after the one that conversion stopped at.  If conversion
     stops because a null character is encountered, *src is set to NULL.

     The mbstate_t argument, ps, is used to keep track of the shift state.  If
     it is NULL, mbsrtowcs() uses an internal, static mbstate_t object, which
     is initialized to the initial conversion state at program startup.

     The mbsnrtowcs() function behaves identically to mbsrtowcs(), except that
     conversion stops after reading at most nms bytes from the buffer pointed
     to by src.

RETURN VALUES
     If successful, and dst is not NULL, the mbsrtowcs() and mbsnrtowcs()
     functions return the number of wide characters stored in the array
     pointed to by dst.

     If dst was NULL then the functions mbsrtowcs() and mbsnrtowcs() return
     the number of wide characters that would have been stored where dst
     points to an infinitely large array.

     If either one of the functions is not successful then (size_t)-1 is
     returned.

ERRORS
     The mbsrtowcs() and mbsnrtowcs() functions will fail if:

     [EILSEQ]           An invalid multibyte character sequence was
                        encountered.

     [EINVAL]           The conversion state is invalid.

SEE ALSO
     mbrtowc(3), mbstowcs(3), multibyte(3), wcsrtombs(3)

STANDARDS
     The mbsrtowcs() function conforms to ISO/IEC 9899:1999 ("ISO C99").

     The mbsnrtowcs() function is an extension to the standard.

FreeBSD 13.1-RELEASE-p6         August 7, 2020         FreeBSD 13.1-RELEASE-p6