strncpy

The function strncpy ( 3 ) can also be used to copy only a part of the source string into the destination .

函数strncpy（3）还可以用来仅把源字符串的一部分复制到目标中。

The example has an implementation of strncpy , where the source and destination strings are checked first , respectively , to be readable and writable .

这个例子有一个strncpy工具，在这个例子中源和目的字符串首先被分别核查，使其能够被读取和写入。

Both strncpy ( 3 ) and strncat ( 3 ) require that you give the amount of space left , not the total size of the buffer .

strncpy（3）和strncat（3）都要求您给出剩余的空间，而不是给出缓冲区的总大小。

The correct way to do this would be to use the strncpy () function instead of strcpy (), and give the maximum number of bytes to copy as BUFSIZ-1 .

复制的正确方法是用strncpy（）函数代替strcpy（），并将要复制的最大字节数定为BUFSIZ-1。

The function strncpy ( 3 ) also doesn 't NUL-terminate its destination if the source string is at least as long as the destination ; this can cause havoc later .

如果源字符串至少和目标一样长，那么函数strncpy（3）还不会使用NUL来结束字符串；这可能会在以后导致严重破坏。

This means that switching from strcpy ( 3 ) to strncpy ( 3 ) can reduce performance & often not a serious problem on today 's computers , but it can still be a nuisance .

这意味着从strcpy（3）切换到strncpy（3）会降低性能――这在如今的计算机上通常不是一个严重的问题，但它仍然是有害的。

Memcpy () joins the ranks of other popular functions like strcpy , strncpy , strcat , strncat which were banned due to their security vulnerability through buffer overruns .

memcpy（）加入到strcpy，strncpy，strcat，strncat等常用函数的队伍中，都是由于可通过缓存溢出进行安全攻击而被禁用。

In theory , strncpy ( 3 ) is the safe replacement for strcpy ( 3 ), but strncpy ( 3 ) also fills the entire destination with NULs once the end of the source string has been met .

从理论上讲，strncpy（3）是strcpy（3）的安全替代者，但是strncpy（3）还会在源字符串结束时使用NUL来填充整个目标空间。

Then , we 'll discuss two examples of the static approach ( standard C strncpy / strncat and OpenBSD 's strlcpy / strlcat ), followed by two examples of the dynamic approach ( SafeStr and C + + 's std : : string ) .

然后，我们将讨论静态方法的两个例子（标准Cstrncpy/strncat和OpenBSD的strlcpy/strlcat），接着讨论动态方法的两个例子（SafeStr和C++的std：：string）。