无法使用 gcc 构建 sigqueue 示例，但 g++可以吗？

发布于 2024-09-25 08:50:46 字数 1002 浏览 4 评论 0原文

我有一个奇怪的构建问题。

我有一个简单的测试程序，它将 sigqueue 发送到另一个进程。

这个小代码示例在我将其构建为 C++ 程序（使用 g++ 编译）时构建并运行但是当我将它编译为 ac 程序（使用 gcc）时，我收到一个错误，他找不到 sigval 结构。

简短的示例：

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <sys/types.h>

int main(int argc, char *argv[])
{
        sigval value;
        value.sival_int = 123;
        sigqueue(0,SIGUSR1, value);
}

请注意，我将 pid 替换为 0 以简化这个问题。

如果我用 gcc 编译，我会得到：

$> gcc sigusr1_mini.c 
sigusr1_mini.c: In function ‘main’:
sigusr1_mini.c:9: error: ‘sigval’ undeclared (first use in this function)
sigusr1_mini.c:9: error: (Each undeclared identifier is reported only once
sigusr1_mini.c:9: error: for each function it appears in.)
sigusr1_mini.c:9: error: expected ‘;’ before ‘value’
sigusr1_mini.c:10: error: ‘value’ undeclared (first use in this function)

我在这里缺少什么，为什么他找不到 sigval 结构？为什么g++能找到呢？

谢谢约翰

原文

I have a strange build problem.

I have a simple test program that sends a sigqueue to another process.

This little code example builds and runs when I build it as a c++ program (compiled with g++)
but when I compile it as a c program (with gcc) I get a error that he can't find the sigval struct.

The short example:

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <sys/types.h>

int main(int argc, char *argv[])
{
        sigval value;
        value.sival_int = 123;
        sigqueue(0,SIGUSR1, value);
}

Please note that I replaced the pid with 0 to simplify this question.

And if I compile with gcc I get this:

gt; gcc sigusr1_mini.c 
sigusr1_mini.c: In function ‘main’:
sigusr1_mini.c:9: error: ‘sigval’ undeclared (first use in this function)
sigusr1_mini.c:9: error: (Each undeclared identifier is reported only once
sigusr1_mini.c:9: error: for each function it appears in.)
sigusr1_mini.c:9: error: expected ‘;’ before ‘value’
sigusr1_mini.c:10: error: ‘value’ undeclared (first use in this function)

What am I missing here, why can't he find the sigval struct?
And why can g++ find it?

Thanks
Johan

分享到QQ

分享到微博