pid

I have problem with Bash, and I don't know why. Under shell, I enter: echo $$ ## print 2433 (echo $$) ## also print 2433 (./getpid) ## print 2602 "getpid" is a C program to get current pid, like: int main() { printf("%d", (int)getpid()); return 0; } What confuses me is that: I think "(command)" is a sub-process (am i right?), and i think its pid should be different with its parent pid, but they are the same, why... when i use my program to show pid between parenthesis, the pid it shows is different, is it right? is '$$' something like macro? Can you help me? $$ is defined to return the process

题目链接： http://acm.hdu.edu.cn/showproblem.php?pid=2104 思路分析：m和n互质即可。与hdu1222相同 http://acm.hdu.edu.cn/showproblem.php?pid=1222 转载于:https://www.cnblogs.com/FCWORLD/archive/2011/04/14/2015666.html 来源： https://blog.csdn.net/weixin_30652897/article/details/99910230

I need to be able to get the PID from a running process (cmd.exe) using the command line. The problem is there are two cmd.exe running. One is under the username SYSTEM and one is compUser. Is there a way that I can grab the PID of the compUser cmd.exe? Edit: This needs further explanation. I'm doing this from a batch file. One of the calls that I'm making in my batch file starts a cmd.exe that never dies. So killing that cmd.exe would be simple: taskkill /F /IM cmd.exe /FI "username eq compUser" The problem is that the batch file that I'm in is being handled by another instance of cmd.exe

最近看到pid控制，分享出来让大家指正一下。 pid的思路还是很简单的，做一个类比。假如你喂了一只宠物狗，你在草坪上和它玩耍。你将一根骨头抛出去，于是狗狗做了以下动作，省略100字，假如最后结果是狗狗成功接住了骨头。来看看省略了些什么细节。狗狗发现了抛飞的骨头，转身向着骨头落下的方向跑，狗狗盯着骨头跑到骨头预计的落点，做了一个潇洒的昂头运动。好，骨头到嘴了！～～表示看着别人家的狗狗好棒～～ 好了，看到这里你已经看完了我对pid的理解，我认为刚才的狗狗就是完美的pid系统，我们用到的pid只是有个会不停的抛骨头的环境罢了，相信这个狗狗都会接住！ 来看看pid微分调节部分，狗狗看到抛飞的骨头，其实狗狗就有了一个骨头落点的分析，在脑子里做了各种运动估算，发现了骨头的预计落点，这就是pid微分调节的作用。 在来看看pid的积分调节部分，狗狗已经知道了骨头预计的落点，于是就向着骨头落点跑去，跑一会有经验的狗狗就会用余光瞅一眼骨头，可以适时的改变运动方向。 最后是帅气而暴力的pid比例调节部分，狗狗顺势一昂头，快准很，接住了骨头。呃，为什么说这个动作比方成比例调节呢，因为比例环境不影响下一次的pid运行，和昂头很像，昂头和下一次接骨头不影响(当然排除这狗狗一次接两根骨头～～) 这时，你又立即抛出下一个骨头，狗狗又从接到骨头的地方奔跑，于是微分环节就进行了下去。 恩，找到这里了

I need to find the PID of the current running process on a Linux platform (it can be a system dependent solution). Java does not support getting the process ID, and JRuby currently has a bug with the Ruby method, Process.pid. Is there another way to obtain the PID? Mike Stone If you have procfs installed, you can find the process id via the /proc/self symlink, which points to a directory whose name is the pid (there are also files here with other pertinent information, including the PID, but the directory is all you need in this case). Thus, with Java, you can do: String pid = new File("/proc

For my Java apps with very long classpaths, I cannot see the main class specified near the end of the arg list when using ps. I think this stems from my Ubuntu system's size limit on /proc/pid/cmdline. How can I increase this limit? You can't change this dynamically, the limit is hard-coded in the kernel to PAGE_SIZE in fs/proc/base.c: 274 int res = 0; 275 unsigned int len; 276 struct mm_struct *mm = get_task_mm(task); 277 if (!mm) 278 goto out; 279 if (!mm->arg_end) 280 goto out_mm; /* Shh! No looking before we're done */ 281 282 len = mm->arg_end - mm->arg_start; 283 284 if (len > PAGE_SIZE)

1. 查看GITLAB的版本号 [tianyu@happylich ~]$ cat /opt/gitlab/embedded/service/gitlab-rails/VERSION 11.3.4-ee 2. 查看GITLAB的状态 [tianyu@happylich ~]$ sudo gitlab-ctl status run: alertmanager: (pid 9623) 191s; run: log: (pid 26940) 26623332s run: gitaly: (pid 9636) 191s; run: log: (pid 26890) 26623334s run: gitlab-monitor: (pid 9648) 191s; run: log: (pid 26903) 26623333s run: gitlab-workhorse: (pid 9651) 190s; run: log: (pid 26871) 26623334s run: logrotate: (pid 9669) 190s; run: log: (pid 26873) 26623334s run: nginx: (pid 10464) 2s; run: log: (pid 26872) 26623334s run: node-exporter: (pid 9680) 189s; run:

Given the pid of a Linux process, I want to check, from a C program, if the process is still running. Issue a kill(2) system call with 0 as the signal. If the call succeeds, it means that a process with this pid exists. If the call fails and errno is set to ESRCH , a process with such a pid does not exist. Quoting the POSIX standard: If sig is 0 (the null signal), error checking is performed but no signal is actually sent. The null signal can be used to check the validity of pid. Note that you are not safe from race conditions: it is possible that the target process has exited and another

I am writing a script to monitor the CPU and MEM of any given process. For that i need to send in the name of the process to be monitored as a commandline argument. For example. ./monitorscript <pname> I need to get the pid of the process in the script so that i can use a ps -p <pid> inside. How do i get the pid of a process given its process name? I understand that there might be multiple processes in the same name. I just want to get the first process out of that list. The answer above was mostly correct, just needed some tweaking for the different parameters in Mac OSX. ps -A | grep -m1

#include <stdio.h> #include <unistd.h> #include <stdlib.h> #include <errno.h> #include <sys/types.h> #include <sys/wait.h> static pid_t fork_child(void) { int pid = fork(); if (pid == -1) { perror("fork"); exit(1); } if (pid == 0) { puts("child: sleeping..."); sleep(10); puts("child: exiting"); exit(0); } return pid; } int waitpid_timeout(pid_t pid, int mseconds) { sigset_t mask, orig_mask; sigemptyset(&mask); sigaddset(&mask, SIGCHLD); if (sigprocmask(SIG_BLOCK, &mask, &orig_mask) < 0) { perror("sigprocmask"); return 1; } else { struct timespec timeout; timeout.tv_sec = mseconds / 1000;