如何在C中获取Linux中进程的PID

I need to kill a process using the kill API. For that I need the process id of the process. I tried to get it using:

我需要使用kill API终止进程。为此我需要进程的进程ID。我试图使用它：

ret = system("pidof -s raj-srv");

but it is not returning the correct value. I dont want to kill the process using this:

但它没有返回正确的值。我不想使用这个来杀死进程：

ret = system("pkill raj");

Is there any API that could be used to get the process id?

是否有任何API可用于获取进程ID？

5 个解决方案

#1

You are getting the return status of system. That's not the pid. You want something like this:

您正在获得系统的返回状态。那不是pid。你想要这样的东西：

char line[LEN];
FILE *cmd = popen("pidof...", "r");

fgets(line, LEN, cmd);
pid_t pid = strtoul(line, NULL, 10);

pclose(cmd);

#2

The system() call doesn't return the output of pidof, it returns pidof's return code, which is zero if it succeeds.

system（）调用不返回pidof的输出，它返回pidof的返回码，如果成功则为零。

You could consume the output of pidof using popen() instead of system(), but I'm sure there's a better way (the way pidof itself uses). Perhaps it wanders through /proc.

您可以使用popen（）而不是system（）来使用pidof的输出，但我确信有更好的方法（pidof本身使用的方式）。也许它徘徊/ proc。

#3

There could be multiple instances of processes running in that case , pidof returns strings of pid seperated by space .

在这种情况下可能有多个进程实例运行，pidof返回由空格分隔的pid字符串。

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

main()
{
        char pidline[1024];
        char *pid;
        int i =0
        int pidno[64];
        FILE *fp = popen("pidof bash","r");
        fgets(pidline,1024,fp);

        printf("%s",pidline);
        pid = strtok (pidline," ");
        while(pid != NULL)
                {

                        pidno[i] = atoi(pid);
                        printf("%d\n",pidno[i]);
                        pid = strtok (NULL , " ");
                        i++;
                }

        pclose(fp);
}

#4

What is returned by the system function is the return code from the command being executed.

系统函数返回的是正在执行的命令的返回码。

What you can do is something like this:

你能做的是这样的：

system("pidof -s raj-srv > /tmp/pid-of-raj-srv");

And then read the contents of the file /tmp/pid-of-raj-srv.

然后读取文件/ tmp / pid-of-raj-srv的内容。

#5

I know it is not a fresh thread, but as I have only recently faced the same question, I will ask you. Did you see one of this:

我知道这不是一个新线程，但由于我最近才遇到同样的问题，我会问你。你有没有看到其中一个：

Get process id by name in C
在C中按名称获取进程ID
C function to find a process ID and kill it
C函数找到进程ID并将其杀死
man sysctl(3)
man sysctl（3）

You can use sysctl to give you the needed information without having to pass through a system( "bla, bla" ) call. It seems to be far more complicated at first, but may be worth depending on your needs.

您可以使用sysctl为您提供所需的信息，而无需通过系统（“bla，bla”）调用。一开始似乎要复杂得多，但根据您的需求可能值得。

#1