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;  

}