请帮我写一段unicode码转换成utf8的C语言代码

以下是一段unicode码转换成utf8的C语言代码：

#include <stdio.h>

void unicode_to_utf8(unsigned int unicode, char *utf8) {
    if (unicode <= 0x7f) {
        utf8[0] = (char)unicode;
        utf8[1] = '\0';
    } else if (unicode <= 0x7ff) {
        utf8[0] = (char)(0xc0 | (unicode >> 6));
        utf8[1] = (char)(0x80 | (unicode & 0x3f));
        utf8[2] = '\0';
    } else if (unicode <= 0xffff) {
        utf8[0] = (char)(0xe0 | (unicode >> 12));
        utf8[1] = (char)(0x80 | ((unicode >> 6) & 0x3f));
        utf8[2] = (char)(0x80 | (unicode & 0x3f));
        utf8[3] = '\0';
    } else if (unicode <= 0x10ffff) {
        utf8[0] = (char)(0xf0 | (unicode >> 18));
        utf8[1] = (char)(0x80 | ((unicode >> 12) & 0x3f));
        utf8[2] = (char)(0x80 | ((unicode >> 6) & 0x3f));
        utf8[3] = (char)(0x80 | (unicode & 0x3f));
        utf8[4] = '\0';
    }
}

int main() {
    unsigned int unicode = 0x4e2d; // 中的unicode码
    char utf8[5];
    unicode_to_utf8(unicode, utf8);
    printf("%s\n", utf8); // 输出：中
    return 0;
}

希望能对你有所帮助！