从打开的“ FILE *”中获取缓冲参数 [英] Get Buffering Parameters From an Open `FILE*`

问题描述

在C语言中，我们可以使用 setvbuf（...）进行设置缓冲区，缓冲区大小和缓冲模式。我很惊讶地发现，在打开 FILE * 的情况下，没有人问过如何读取这些值（例如 stdout 或由用户提供）。即，如何实现 getvbuf（...）例程（甚至其中的一部分）？

In C, we can use setvbuf(...) to set a buffer, its size, and a buffering mode. I am surprised to find that no one has asked how to read these values, given an open FILE* (e.g. stdout, or user-provided). I.e., how could one implement a "getvbuf(...)" routine (or even a subset of it)?

void getvbuf(FILE* stream, char** pbuf,int* bufmode,size_t* bufsize);

推荐答案

我认为它不可以作为标准。但是Solaris引入了一些非标准的机制来查询这些属性中的少数几个，这些属性在GNU C编译器中也可用。

I don't think its available as part of the standard. However Solaris has introduced some non standard mechanism to query few of these properties which are also available in GNU C compiler.

请检查此以获得更多详细信息： ：//www.gnu.org/software/libc/manual/html_node/Controlling-Buffering.html rel = nofollow noreferrer> https://www.gnu.org/software/libc/manual/html_node/Controlling- Buffering.html

Check this for more details: https://www.gnu.org/software/libc/manual/html_node/Controlling-Buffering.html

我很想知道您想在其中使用getvbuf（..）之类的用例。

I was curious to know the use case where you want to do a getvbuf(..) kind of stuff.

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