任何功能查询已分配块的大小？ [英] Any function to query the size of an allocated block?

问题描述

我意识到，任何这样的功能很可能是非标准，但没关系我的用例。基本上，我需要一种方法，我可以传递一个指针，返回的大小（即是由previous调用返回的malloc（）函数的指针）（即使它通过的glibc的系统调用（）接口只露）方框在指针指向。难道这样的事情存在？

I realize that any such function is likely to be non standard, but that's ok for my use case. Basically, I need a method (even if it's only exposed through glibc's syscall() interface) that I can pass a pointer to (a pointer that was returned by a previous call to malloc()) that returns the size of the block the pointer points at. Does such a thing exist?

推荐答案

据我所知，至少有在C90 / C99无此功能。有些系统，主要是libc中，提供的功能来获得分配的大小（例如malloc_size（）在Mac OS X），但这是不可移植的，也许你应该避免使用，在最好的。

So far as I know, there is no such function at least in C90/C99. Some systems, mostly libc, provide functions to get allocated size (e.g. malloc_size() in Mac OS X), but this is not portable and probably you should avoid using that at best.

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