Defined in header <wchar.h> | ||
|---|---|---|
| (1) | ||
size_t mbsrtowcs( wchar_t* dst, const char** src, size_t len, mbstate_t* ps ); | (since C95) | |
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);
| (2) | (since C11) |
*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:*src is set to NULL and *ps represents the initial shift state.*src is set to point at the beginning of the first unconverted multibyte character.len. *src is set to point at the beginning of the first unconverted multibyte character. This condition is not checked if dst==NULL.retval
dst after len wide characters were written, then L'\0' is stored in dst[len], which means len+1 total wide characters are writtendstsz
src and dst overlap, the behavior is unspecified.retval, ps, src, or *src is a null pointer dstsz or len is greater than RSIZE_MAX/sizeof(wchar_t) (unless dst is null) dstsz is not zero (unless dst is null) dstsz multibyte characters in the *src array and len is greater than dstsz (unless dst is null) mbsrtowcs_s is only guaranteed to be available if __STDC_LIB_EXT1__ is defined by the implementation and if the user defines __STDC_WANT_LIB_EXT1__ to the integer constant 1 before including wchar.h.| 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 |
L'\0', written to the character array. If dst==NULL, returns the number of wide characters that would have been written given unlimited length. On conversion error (if invalid multibyte character was encountered), returns (size_t)-1, stores EILSEQ in errno, and leaves *ps in unspecified state.dst, is stored in *retval), non-sero on error. In case of a runtime constraint violation, stores (size_t)-1 in *retval (unless retval is null) and sets dst[0] to L'\0' (unless dst is null or dstmax is zero or greater than RSIZE_MAX)#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🍌"
}Output:
Wide string: zß水🍌 The length, including L'\0': 5
|
(C11) | converts a narrow multibyte character string to wide string (function) |
|
(C95) | converts the next multibyte character to wide character, given state (function) |
|
(C95)(C11) | converts a wide string to narrow multibyte character string, given state (function) |
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