将 C 程序设置为行缓冲区将不起作用 [英] Setting C program to line buffer won't work

问题描述

我试图强制我的 C 程序行缓冲(stdout 将被 java 程序捕获)，但它似乎总是完全缓冲.下面是一些示例代码:

I'm trying to force my C program to line buffer (stdout is going to be captured by a java program), but it always seems to fully buffer instead. Here is some sample code:

#include <stdio.h>
#include <stdlib.h>

int main(){
    char c;
    setvbuf(stdout, NULL, _IOLBF, BUFSIZ);
    printf("Hello world\n");
    c = getchar();
    printf("got char: %c\n", c);
}

如果我指定 _IOLBF 或 _IOFBF，那么在我输入字符之前我看不到输出.只有当我使用 _IONBF 时，我才会在 getchar() 之前看到输出._IOLBF 不应该做同样的事情，因为Hello World\n"包含一个 '\n'?

If I specify _IOLBF or _IOFBF, then I don't see an output until I input a char. Only if I use _IONBF will I see output before the getchar(). Shouldn't _IOLBF do the same since "Hello World\n" contains a '\n'?

我使用的是 Visual C++ 2005.

I am using visual c++ 2005.

谢谢

推荐答案

根据 此 Microsoft 文档:

_IOLBF:对于某些系统，这提供了行缓冲.但是，对于 Win32，其行为与 _IOFBF - Full Buffering 相同.

_IOLBF: For some systems, this provides line buffering. However, for Win32, the behavior is the same as _IOFBF - Full Buffering.

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