# mbsinit

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< c‎ | string‎ | multibyte

Defined in header `<wchar.h>` |  |
int mbsinit( const mbstate_t* ps); |  | (since C95)

If `ps` is not a null pointer, the `mbsinit` function determines whether the pointed-to mbstate_t object describes the initial conversion state.

### Notes

Although a zero-initialized mbstate_t always represents the initial conversion state, there may be other values of mbstate_t that also represent the initial conversion state.

### Parameters

ps | - | pointer to the mbstate_t object to examine

### Return value

​0​ if `ps` is not a null pointer and does not represent the initial conversion state, nonzero value otherwise.

### Example

Run this code

    #include <locale.h>
    #include <string.h>
    #include <stdio.h>
    #include <wchar.h>

    int main(void)
    {
        // allow mbrlen() to work with UTF-8 multibyte encoding
        setlocale(LC_ALL, "en_US.utf8");
        // UTF-8 narrow multibyte encoding
        const char* str = u8"水"; // or u8"\u6c34" or "\xe6\xb0\xb4"
        static mbstate_t mb; // zero-initialize
        (void)mbrlen(&str[0], 1, &mb);
        if (!mbsinit(&mb)) {
            printf("After processing the first 1 byte of %s,\n"
                   "the conversion state is not initial\n\n", str);
        }

        (void)mbrlen(&str[1], strlen(str), &mb);
        if (mbsinit(&mb)) {
            printf("After processing the remaining 2 bytes of %s,\n"
                   "the conversion state is initial conversion state\n", str);
        }
    }

Output:

    After processing the first 1 byte of 水,
    the conversion state is not initial

    After processing the remaining 2 bytes of 水,
    the conversion state is initial conversion state

### References

- C11 standard (ISO/IEC 9899:2011):

  - 7.29.6.2.1 The mbsinit function (p: 441-442)

- C99 standard (ISO/IEC 9899:1999):

  - 7.24.6.2.1 The mbsinit function (p: 387-388)

### See also

mbstate_t (C95) | conversion state information necessary to iterate multibyte character strings (class)

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