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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.
The mbsnrtowcs() function is an extension to the standard.
FreeBSD 14.0-RELEASE-p11 August 7, 2020 FreeBSD 14.0-RELEASE-p11