mbsrtowcs, mbsrtowcs_s

Header: <wchar.h>

Converts a null-terminated multibyte character sequence, which begins in the conversion state described by *ps, from the array whose first element is pointed to by *src to its wide character representation. If dst is not null, converted characters are stored in the successive elements of the wchar_t array pointed to by dst. No more than len wide characters are written to the destination array. Each multibyte character is converted as if by a call to mbrtowc. The conversion stops if: The multibyte null character was converted and stored. *src is set to null pointer value and *ps represents the initial shift state.An invalid multibyte character (according to the current C locale) was encountered. *src is set to point at the beginning of the first unconverted multibyte character.the next wide character to be stored would exceed len. *src is set to point at the beginning of the first unconverted multibyte character. This condition is not checked if dst is a null pointer.

# Declarations

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

(since C95) (until C99)

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

(since C99)

errno_t mbsrtowcs_s( size_t *restrict retval,
wchar_t *restrict dst, rsize_t dstsz,
const char **restrict src, rsize_t len,
mbstate_t *restrict ps );

(since C11)

# Parameters

dst: pointer to wide character array where the results will be stored
src: pointer to pointer to the first element of a null-terminated multibyte string
len: number of wide characters available in the array pointed to by dst
ps: pointer to the conversion state object
dstsz: max number of wide characters that will be written (size of the dst array)
retval: pointer to a size_t object where the result will be stored

# Example

#include <stdio.h>
#include <locale.h>
#include <wchar.h>
#include <string.h>
 
void print_as_wide(const char* mbstr)
{
    mbstate_t state;
    memset(&state, 0, sizeof state);
    size_t len = 1 + mbsrtowcs(NULL, &mbstr, 0, &state);
    wchar_t wstr[len];
    mbsrtowcs(&wstr[0], &mbstr, len, &state);
    wprintf(L"Wide string: %ls \n", wstr);
    wprintf(L"The length, including L'\\0': %zu\n", len);
}
 
int main(void)
{
    setlocale(LC_ALL, "en_US.utf8");
    print_as_wide(u8"z\u00df\u6c34\U0001f34c"); // u8"zß水🍌"
}

mbsrtowcs, mbsrtowcs_s

# Declarations

# Parameters

# Example

# See also