strcpy、strncpy 和安全的strncpy_s

strcpy和strncpy摘于linux 内核源码的/lib/string.c

char *self_strcpy(char *dest, const char *src)
{
        char *tmp = dest;

        while ((*dest++ = *src++) != '\0')
                /* nothing */;
        return tmp;
}

char *self_strncpy(char *dest, const char *src, size_t count)
{
        char *tmp = dest;

        while (count) {
                if ((*tmp = *src) != 0)
                        src++;
                tmp++;
                count--;
        }
        return dest;
}

针对处理self_strncpy_s函数接口

个人定义self_strncpy_s接口，目的是解决，防止溢出，在不够buffer时可以处理最大值的字符串数据。

例如：

|0000000000|  

|xxxxxxxxxxx|  复制到

|00000000|     得到结果是

|xxxxxxxxx| 

源码实现：

char *self_strncpy_s(char *dest, size_t buffer, const char *src, size_t size)
{
        if (size > buffer)
                size = buffer;

        char *tmp = dest;
        while (size) {
                if ((*tmp = *src) != 0)
                        src++;
                tmp++;
                size--;
        }
        dest[buffer] = '\0';/*avoid ending symbol character*/
        return dest;
}