A process is an instance of a computer program that is being executed.

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Script to send email alert only when process change state

Below script checks whether MStrsvr process is running or not . The issue I'm facing is if i schedule a cron tab to run this script for every 1 hour it will throw email alert every 1hr that "MSTRSvr ...
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3answers
896 views

Limiting a specific shell's internet bandwidth usage

I want update my linux in one shell but by default wget or axel in updater use all the bandwidth. How can I limit the speed in this shell? I want other shells to have a fair share, and to limit ...
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5answers
13k views

How to send keystrokes (F5) from terminal to a process?

I'm using an Raspberry Pi in combination with Chromium (kiosk mode) to show up some stats. The Pi doesn't have an connected keyboard so I searched for a solution to send keystrokes from the terminal ...
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2answers
111 views

How can I determine if a process is running unseen in terminal?

For ex - if I enter ping one.com the process will keep running - if I want to stop that process, I can type Ctrl C which if I'm not mistaken, will kill the process completely. If instead, I stop it ...
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1answer
36 views

Process Flag 1: Forked but didn't exec (use case?)

In the man page for ps, it lists process flag 1 as "process forked but didn't exec". What would be a common use case/situation for a process to be in this state?
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1answer
5k views

Nice and child processes

Can someone tell me what is the relationship between a specified nice level and child processes? For example, if I have a default nice of 0, and I start a script with nice 5, which in turn starts ...
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1answer
44 views

Most elegant way to terminate straced program

I want to capture a certain thing with strace and then immediately exit. This way the program stays alive: strace ... program 2>&1 | grep --line-buffered ... | read line. Is there a simple way ...
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9answers
4k views

How can I kill a process and be sure the PID hasn't been reused

Suppose, for example, you have a shell script similar to: longrunningthing & p=$! echo Killing longrunningthing on PID $p in 24 hours sleep 86400 echo Time up! kill $p Should do the trick, ...
3
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1answer
303 views

Process not closing when stdin is closed

I am starting a process with a program. I expect the process to terminate when the program does, since it loses its stdin. I terminated the program, then went to the proc/pid/fd for the process, ...
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0answers
15 views

Starting isolated namespace inside network namespace

I've managed to create two network namespaces (ns1 and ns2) and connect them via veth connection. They can ping each other fine, and even ssh one into another (provided I started sshd). What I would ...
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3answers
470 views

bash - get pid for a script using the script filename

I have two scripts: running_script script_one I need to get the PID for the/any instances of running_script running under a username, and then pkill to stop the running_script and daughter ...
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1answer
849 views

Why can I list other users processes without root permission?

Using ps -aux or top, I can list other users running processes, but i'm neither running as root or making use of sudo, why ?
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98 views

Differences between system processes, and user processes, kernel control paths and kernel thread

My understanding is that a process always runs in user mode and uses user space only, and a kernel always runs in kernel mode and uses kernel space only. But I feel that I might not be correct, ...
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There are stopped jobs (on bash exit)

I get the message There are stopped jobs. when i try to exit a bash shell sometimes. Here is a reproducible scenario in python 2.x: ctrl+c is handled by the interpreter as an exception. ctrl+z ...
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3answers
54 views

On `fork`, children processes, and “subshells”

This post is basically a follow-up to an earlier question of mine. From the answer to that question I realized that not only I don't quite understand the whole concept of a "subshell", but more ...
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6answers
14k views

How can I close a terminal without killing its children (without running `screen` first)?

sometimes I run an app in the gnome-terminal, but then I suddenly have to restart gnome or something. I guess the answer to the question is also useful then I want to disconnect from SSH where ...
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2answers
72 views

Service vs Process?

chkconfig has five distinct functions: adding new services for management, removing services from management, listing the current startup information for services, changing the startup ...
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1answer
25 views

Embedding a binary and exec it, feasibility

I have a binary daemon that depends on another binary daemon at runtime to exist; I don't like this arrangement. (My code works on both OS X and Linux I say linux because I believe its okay to only ...
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1answer
81 views

bash does not exit on abnormal exit of child process due to signal

I try really hard to understand what I am doing wrong and why? I have a launch.sh script which launches process.sh. launch.sh #!/bin/bash while true; do ./process.sh done process.sh ...
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20 views

killing subprocesses and traps

I have the following two scripts which simulate some work: start.sh simply launches 2 (mpi) processes with script mpiproc.sh. start.sh #!/bin/bash function trap_with_arg() { func="$1" ; shift ...
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2answers
134 views

Terminal command (called not from SU) that would restrict process from writing to all directories but one?

We have an app testApp. We have a folder called notRestricted in the directory where we run app from. We want to limit access of the app to file system so that app could write only to that folder (we ...
4
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2answers
129 views

Hook action on process creation

Is it possible to hook a script execution on each process creation? Essentially the equivalent of inotifywait to monitor disk activity but applied to the process table. It would be to allow to do an ...
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2answers
42 views

What is the default memory allocation for shell process by linux

What is the default memory allocation for shell process by Linux , i mean is there any upper limit for shell process or any process.
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1answer
46 views

Possible to identify defunct process from pgrep

I am using pgrep for a bunch of things, however I can't get pgrep to list if the process is defunct. Running ps adds to the end of the item <defunct> but pgrep does not, is there anyway to do ...
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1answer
117 views

cpu usage is 100% but top doesn't show any process using it

First of all, I forgot to save the process list. I had to reboot the server so I can't give much information. I have a small VPS. The cpu usage was 100% in both top and in the control panel graphs, ...
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3answers
59 views

How do I get the first branch PID of an application in pstree command?

I want to get PPID of chromium browser. When I launch chromium-browser it launches many child processes with the same name. For example: $ pidof /usr/lib/chromium-browser/chromium-browser 8963 ...
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4answers
40k views

How to attach terminal to detached process?

I have detached a process from my terminal, like this: $ process & That terminal is now long closed, but process is still running and I want to send some commands to that process's stdin. Is ...
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0answers
21 views

Pipe output of process that's already running

I've got a process that spews out a lot of output, and it's going to be running for the next hour. I forgot to pipe its output through my awk script before I started running it. Now my terminal is ...
255
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12answers
230k views

What if 'kill -9' does not work?

I have a process I can't kill with kill -9 <pid>. What's the problem in such a case, especially since I am the owner of that process. I thought nothing could evade that kill option.
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4answers
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How to get the pid of the last executed command in shell script?

I want to have a shell script like this: my-app & echo $my-app-pid But I do not know how the get the pid of the just executed command. I know I can just use the jobs -p my-app command to grep ...
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2answers
68 views

How do I kill a process given its “command”?

I have a process called "P1", right now the way I kill the process is: $ ps aux | grep "P1" " Now it returns two processes related to "P1": one is the actual P1 process I want to kill, the other one ...
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1answer
35 views

Kill command also kills other process

I have a very simple script, let's call it foo.sh. It's this: #!/bin/sh sxhkd & panel & where panel is a script (I won't post it here because it's very long and I don't think it would be ...
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3answers
107 views

Process scheduling data on linux

I am doing a project on OS and require the process scheduling data for an operating system. The data has to include the list of all processes in short-term-scheduler and long-term-scheduler along with ...
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2answers
69 views

How to “track” newly created processes?

I know that with ps I can see the list or tree of the current processes running in the system. But what I want to achieve is to "follow" the new processes that are created when using the computer. As ...
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2answers
48 views

How to prevent a process from hanging the computer?

A process can cause the computer to "freeze" for example when exhausting CPU or swap. Is there a way to prevent this from happening? For example by setting the max %CPU or IO MB/s that can be granted ...
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0answers
51 views

RAM not used by process? Then who uses it? [closed]

I don't understand who uses my RAM. I can see clearly that it's used, but I have no ideea who uses it. Do you have any ideea what could be wrong here? I'm experiencing random spikes of high memory ...
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1answer
85 views

Kill a running shell script, and kill all process running within it

I have a shell script running in the background, which runs 5 different jobs. When I run the shell script all 5 jobs start running in order. When I kill this shell, whichever process is running, will ...
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0answers
11 views

What is the equivalent of pstop on OSX?

Is there an equivalent of pstop in OSX? How is pstop different to kill?
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2answers
101 views

From bash, spawn two processes and exit both if either sibling exits

From bash, I am spawning two processes. These two processes depend on each other. I want both to exit if either one dies. What is the cleanest way to do that? Currently I have the following: # start ...
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1answer
146 views

Weblogic process just killed suddenly on redhat linux

One of the process on my WAS killed at dawn. 6 process run on this server. But only one process just killed. I don't know how to fix it. This is Weblogic last log that before process killed. ...
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1answer
101 views

The sum of % in the CPU column doesn't match the total CPU % row [duplicate]

I don't understand why the sum of % in the cpu column in top doesn't match the total CPU % row: Text version with slightly different values: ubuntu@server:~$ top top - 23:20:21 up 5:18, 3 users, ...
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1answer
39 views

What happens to a process handle when the process has stopped?

If I have a handle of a process and that process has stopped, Do I need to close the handle? Can I use the handle to rerun the process? Can I use the handle to find out information about the ...
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3answers
53 views

Process in Unix

When I log into my unix terminal and just do ps: bash-4.3$ ps PID TTY TIME CMD 7 pts/0 00:00:00 sh 16 pts/0 00:00:00 bash 17 pts/0 00:00:00 ps I know bash process is ...
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1answer
40 views

When is a port considered being used?

I am getting port in use cannot bind on process restarts. I am trying to find out when a port is considered being used? Is it only when in LISTEN mode? Can it also be if a connection is open to the ...
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1answer
59 views

How do you tell what the return code of a process is when it exits and where is the value usually documented?

If a process runs and exits it returns a non-zero status (personnaly I prefer the term return code); or even a zero status I know that the value is there (mostly because I've done C++ programming and ...
0
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1answer
43 views

Downsides of processes with high virtual size but low RAM and GPU memory use

I have noticed that some of my processes take a lot of virtual size in my computer. I understand that the virtual size of a process is the sum of memory it is actually using, memory it has mapped into ...
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1answer
26k views

What does this process STAT indicates?

If you check the STAT column in above image you will see Ss S S< SN and R+ What does this indicates ? Process states. If yes,Then what is the significance of 'Ss S< SN and R+'?
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Why does killall command kill only one instance of the process?

Sometimes I need to kill Google Chrome (of which I have 2 windows/instances opened). Both instances are not in incognito mode. What I do is: (on Debian 8) killall chrome && killall chrome ...
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1answer
62 views

Is forcing an application to release some the allocated memory possible?

Ever since I came back to Firefox a year or so ago I have been facing the same issue over and over again - the browser just keeps eating up my memory. The problem arises from (maybe the incorrect ...
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1answer
1k views

Change the parent process of a process?

Is it possible to change the parent process of a process? If yes, how? For example, how does screen manage to attach a screen session and the processes running inside it to different shell ...