的strcpy（）的返回值 [英] strcpy() return value

问题描述

很多标准C库）的功能，特别是那些字符串处理，而最显着的strcpy（，分享的原型如下：

A lot of the functions from the standard C library, especially the ones for string manipulation, and most notably strcpy(), share the following prototype:

char *the_function (char *destination, ...)

这些函数的返回值实际上是一样的提供目标。为什么你会浪费的东西冗余的返回值？它更有意义的这种功能为无效或返回有用的东西。

The return value of these functions is in fact the same as the provided destination. Why would you waste the return value for something redundant? It makes more sense for such a function to be void or return something useful.

我唯一的猜测，为什么这是是，它更容易，更方便地窝函数调用的另一位前pression，例如：

My only guess as to why this is is that it's easier and more convenient to nest the function call in another expression, for example:

printf("%s\n", strcpy(dst, src));

还有没有其他合理的理由来证明这个成语？

Are there any other sensible reasons to justify this idiom?

推荐答案

作为埃文指出，这是可以做到像

as Evan pointed out, it is possible to do something like

char* s = strcpy(malloc(10), "test");

例如。分配的malloc（）的内存的值，而无需使用辅助变数。

e.g. assign malloc()ed memory a value, without using helper variable.

（这个例子是不是最好的之一，它会崩溃在内存不足的情况​​，但这个想法是显而易见的）

(this example isn't the best one, it will crash on out of memory conditions, but the idea is obvious)

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