mbrtowc
Defined in header
<wchar.h>
|
||
(since C95) | ||
Converts a narrow multibyte character to a wide character.
If s
is not a null pointer, inspects at most n
bytes of the multibyte character string, beginning with the byte pointed to by s
to determine the number of bytes necessary to complete the next multibyte character (including any shift sequences). If the function determines that the next multibyte character in s
is complete and valid, converts it to the corresponding wide character and stores it in *pwc (if pwc
is not null).
If s
is a null pointer, the values of n
and pwc
are ignored and call is equivalent to mbrtowc(NULL, "", 1, ps).
If the wide character produced is the null character, the conversion state stored in *ps is the initial shift state.
Contents |
[edit] Parameters
pwc | - | pointer to the location where the resulting wide character will be written |
s | - | pointer to the multibyte character string used as input |
n | - | limit on the number of bytes in s that can be examined |
ps | - | pointer to the conversion state used when interpreting the multibyte string |
[edit] Return value
The first of the following that applies:
- 0 if the character converted from
s
(and stored in pwc if non-null) was the null character - the number of bytes [1...n] of the multibyte character successfully converted from
s
- (size_t)-2 if the next
n
bytes constitute an incomplete, but so far valid, multibyte character. Nothing is written to *pwc. - (size_t)-1 if encoding error occurs. Nothing is written to
*pwc
, the value EILSEQ is stored in errno and the value of *ps is left unspecified.
[edit] Example
#include <stdio.h> #include <locale.h> #include <string.h> #include <wchar.h> // print multibyte string to wide-oriented stdout // equivalent to wprintf(L"%s\n", ptr); void print_mb(const char* ptr) { mbstate_t state; memset(&state, 0, sizeof state); const char* end = ptr + strlen(ptr); int len; wchar_t wc; while((len = mbrtowc(&wc, ptr, end-ptr, &state)) > 0) { wprintf(L"Next %d bytes are the character %lc \n", len, wc); ptr += len; } } int main(void) { setlocale(LC_ALL, "en_US.utf8"); // UTF-8 narrow multibyte encoding print_mb(u8"z\u00df\u6c34\U0001F34C"); // or u8"zß水🍌" }
Output:
Next 1 bytes are the character z Next 2 bytes are the character ß Next 3 bytes are the character 水 Next 4 bytes are the character 🍌
[edit] References
- C11 standard (ISO/IEC 9899:2011):
-
- 7.29.6.3.2 The mbrtowc function (p: 443)
- C99 standard (ISO/IEC 9899:1999):
-
- 7.24.6.3.2 The mbrtowc function (p: 389)
[edit] See also
converts the next multibyte character to wide character (function) |
|
(C95)(C11)
|
converts a wide character to its multibyte representation, given state (function) |
C++ documentation for mbrtowc
|