pid | 易学教程

Getting PID of process in Shell Script

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问题 I am writing one shell script and I want to get PID of one process with name as "ABCD". What i did was : process_id=`/bin/ps -fu $USER|grep "ABCD"|awk '{print $2}'` This gets PID of two processes i.e. of process ABCD and the GREP command itself what if I don't want to get PID of GREP executed and I want PID only of ABCD process? Please suggest. 回答1: Just grep away grep itself! process_id=`/bin/ps -fu $USER| grep "ABCD" | grep -v "grep" | awk '{print $2}'` 回答2: Have you tried to use pidof ABCD

BASH - Check if PID Exists

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问题 I want to stall the execution of my BASH script until a process is closed (I have the PID stored in a variable). I'm thinking while [PID IS RUNNING]; do sleep 500 done Most of the examples I have seen use /dev/null which seems to require root. Is there a way to do this without requiring root? Thank you very much in advance! 回答1: kill -s 0 $pid will return success if $pid is running, failure otherwise, without actually sending a signal to the process, so you can use that in your if statement

What is the difference between a Process' pid, ppid, uid, euid, gid and egid?

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问题 Context: I'm getting the current Ruby process ID. Process.pid #=> 95291 Process.ppid #=> 95201 Process.uid #=> 501 Process.gid #=> 20 Process.euid #=> 501 Process.egid #=> 20 回答1: In order: pid : The is the process ID (PID) of the process you call the Process.pid method in. ppid : The PID of the parent process (the process that spawned the current one). For example, if you run ruby test.rb in a bash shell, PPID in that process would be the PID of Bash. uid : The UNIX ID of the user the

How can I check from Ruby whether a process with a certain pid is running?

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问题 If there is more than one way, please list them. I only know of one, but I'm wondering if there is a cleaner, in-Ruby way. 回答1: If it's a process you expect to "own" (e.g. you're using this to validate a pid for a process you control), you can just send sig 0 to it. >> Process.kill 0, 370 => 1 >> Process.kill 0, 2 Errno::ESRCH: No such process from (irb):5:in `kill' from (irb):5 >> 回答2: The difference between the Process.getpgid and Process::kill approaches seems to be what happens when the

JVM调优、工具使用与故障分析

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一、 JDK运行内存调整： JDK7 -Djdk.tls.ephemeralDHKeySize=2048 -server -Xms512m -Xmx1024m -XX:PermSize=512m -XX:MaxPermSize=512m -XX:MaxNewSize=600m -XX:+UseConcMarkSweepGC -XX:MaxTenuringThreshold=6 -XX:+ExplicitGCInvokesConcurrent JDK8 JAVA_OPTS="-Xms1024m -Xmx2048m -Xss1024K -XX:MetaspaceSize=512m -XX:MaxMetaspaceSize=1024m" TOMCAT调整（Windows）： catalina.bat： SET CATALINA_OPTS=-server -Xms512m -Xmx1024m -XX:PermSize=512m -XX:MaxPermSize=512m -XX:MaxNewSize=600m -XX:+UseConcMarkSweepGC -XX:MaxTenuringThreshold=6 -XX:+ExplicitGCInvokesConcurrent TOMCAT调整（Linux）： catalina.sh: CATALINA_OPTS="-server

What is the ___mac_get_pid symbol in a node profile?

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问题 I am profiling some multi-process nodejs code run on OSX. I'm seeing: [C++]: ticks total nonlib name 23398 63.6% 63.8% ___mac_get_pid What is ___mac_get_pid ? It's name is certainly suggestive that it's some code that "gets a PID on a Mac", but the time seems excessive. Googling has provided nothing useful. 回答1: __mac_get_pid is the syscall behind mac_get_pid library function. It is described in man page mac_get : http://man.cx/mac_get(3) mac_get_pid .. get the label of a file, socket, socket

What is the ___mac_get_pid symbol in a node profile?

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不完全微分pid的matlab实现

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一、背景从PID控制的基本原理我们知道，微分信号的引入可改善系统的动态特性，但也存在一个问题，那就是容易引进高频干扰，在偏差扰动突变时尤其显出微分项的不足。为了解决这个问题人们引入低通滤波方式来解决这一问题。二、解决办法上面两种形式都可以，下面将对第一种形式进行m语言仿真和simuink仿真。三、仿真被控对象为：… 采样时间20s 滤波器为：1/（180s+1） % 程序中m用来选择是否用不完全篇pid % m=1：用不完全篇pid % m=2：不用不完全篇pid，用普通pid clear all ; close all ; % 获取控制对象离散化模型 ts = 20 ; % 采样时间 sys = tf ( [ 1 ] , [ 60 , 1 ] , 'inputdelay' , 80 ) ; dsys = c2d ( sys , ts , 'zoh' ) ; [ num , den ] = tfdata ( dsys , 'v' ) ; % 获取滤波器离散化模型 sys1 = tf ( [ 1 ] , [ 180 , 1 ] ) ; % 滤波器模型 dsys1 = c2d ( sys1 , ts , 'tucsin' ) ; % 模型离散化 [ num1 , den1 ] = tfdata ( dsys1 , 'v' ) ; d_filter_out_1 = 0 ; y

What is the PID in the host, of a process running inside a Docker container?

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问题 There are several processes running in a Docker container, their PIDs are isolated in the container namespace, is there a way to figure out what are their PIDs on the Docker host? For example there is an Apache web server running inside a Docker container, (I use Apache+PHP image from Docker Hub), and the Apache, when it starts, creates more worker processes inside the container. Those worker processes are actually handling incoming requests. To view these processes I run pstree inside the

If I have a process, and I clone it, is the PID the same?

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问题 Just a quick question, if I clone a process, the PID of the cloned process is the same, yes ? fork() creates a child process where the PID differs, but everything else is the same. Vfork() creates a child process with the same PID. Exec works to change a process currently in execution to something else. Am I correct in all of these statements ? 回答1: Not quite. If you clone a process via fork/exec, or vfork/exec, you will get a new process id. fork() will give you the new process with a new