c strncat函数代码实现

char  * Mystrncat(char * front, const char *back, size_t count)
{
    char *temp = front;
    while (*front++) {}

    front--;
    while (count--) 
    {
        if (!(*front++ = *back++))
        {
            return temp;
        }
    }
    *front = '';

    return temp;
}