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

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4
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8k views

How to list processes locking file?

Using flock, several processes can have a shared lock at the same time, or be waiting to acquire a write lock. How do I get a list of these processes? That is, for a given file X, ideally to find the ...
2
votes
2answers
216 views

a handy tool to measure memory consumption of a program [duplicate]

I develop a C code on Debian. I am looking for a program to monitor memory consumption of my code in real-time. The only value I care is the maximum RAM consumption, it should hold the value even if ...
2
votes
1answer
601 views

How to see process created by specific user in Unix/linux

I want to see list of process created by specific user or group of user in Linux Can I do it using ps command or is there any other command to achieve this?
2
votes
0answers
72 views

Linux child processes not being culled [closed]

This is causing significant problems for script portability between BSD and Linux. I am on a CentOS 6.4 where this happens. I have a nice compact test case: bash -c "inotifywait -mcr . | sed ...
34
votes
2answers
1k views

How can I check what signals a process is listening to?

How can I verify whether a running process will catch a signal, or ignore it, or block it? Ideally I'd like to see a list of signals, or at least not have to actually send the signal to check.
1
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0answers
224 views

gnome-terminal cmd leaving processes open after closing parent window

The following simple command should demonstrate my issue: gnome-terminal --tab -t "Tab 1" -e "/bin/bash" --tab -t "Tab 2" -e "/bin/bash" This should open a new window with two tabs and an active ...
1
vote
2answers
246 views

How to kill a script which starts new processes?

The following is a Python application which spans a few threads, then spawns a new process of itself and exits: $ cat restart.py import os import random import signal import sys import threading ...
0
votes
3answers
636 views

How can I start a process using cpulimit?

I am trying to use cpulimit for testing an app I'm developing under low resource conditions, and I need the process to start under the influence of cpulimit. It is not sufficient to start the program ...
0
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2answers
219 views

what is an application pool?

I'm reading this article: http://www.modrails.com/documentation/Architectural%20overview.html#web_app_models It talks about how Phusion Passenger extends Apache2 to act as an application server. ...
3
votes
1answer
219 views

When vfork is called is parent process really suspended?

As much as I know when vfork is called child process uses the same address space as that of the parent and any changes made by the child process in parents variables are reflected onto parents ...
3
votes
2answers
230 views

How do I know if acct is running? (The Linux user accounting system)

I have installed the acct package and it is running because I can see file activity in the log file. I know there is the command accton on to turn it on, but how do I determine that its running short ...
0
votes
1answer
96 views

What is meant by “a process has open handles to system objects”? [closed]

The following are qualities of a process: virtual address space executable code open handles to system objects a security context a unique process identifier environment variables a priority class ...
2
votes
4answers
749 views

Process is eating all of the CPU time

Is there any magic command to track down which process is starting this perl task that is eating 100% of CPU time? I have this problem on several machines where JBoss AS is installed.
14
votes
3answers
7k views

Which process has PID 0?

I'm looking for the process started in Linux which has process ID 0. I know init has PID 1 , which is the first process in Linux, is there any process with PID 0?
3
votes
3answers
65 views

Contents of stack area of a process

I've been going through some Unix text books and I can't have a clear picture on the contents of the stack area of the process. Can anyone please explain or point out some references?
-3
votes
2answers
201 views

Bash operator & not working [closed]

As per the bash reference, we can give a non-blocking command by ending it with an ampersand(&) character. However, when I try the below command its not working: python -m SimpleHTTPServer ...
3
votes
2answers
153 views

Current environmental variables of a process

This question relates to this answer. Is it possible to get the current (not initial) environmental variables of a process by making a child process and checking its initial environmental variables? ...
3
votes
4answers
434 views

How to get the id of a very short child process if the parent is known?

I'm looking for a way to get the PID of a short child process in Linux. The process is instant from a human perspective. I know the parent process which will spawn the child process. Is there a way ...
2
votes
2answers
102 views

How to get environmental variables of a very short process?

I have a very short process for which i want to check the environmental variables for debugging purposes. The process is instant from a human perspective. The example illustrates it better. Example ...
0
votes
2answers
325 views

what is a background process?

Here is a common definition of a background process: "A background process is a program that is running without user input. A number of background processes can be running on a multitasking operating ...
4
votes
3answers
1k views

Possible to get SMS/text message notification when process ends/is killed?

There are scripts that will send an e-mail when a server process is finished. However, I do not want to check my email every so often just to see whether a job has finished. Therefore I'd like to get ...
1
vote
1answer
92 views

Find if a process terminates in a specific amount of time

I am running a program.Inside this program i run a specific command and i use ulimit command to terminate the running of that command if it exceeds an amount of time.To be more clear i run this: ...
2
votes
1answer
228 views

pmap and memory usage

On Ubuntu 12.04, I have several apache2 processes running (the 1130 parent and the children it spawned), and as you can see, they have around 300-400 mb of virtual memory and 10 mb of resident memory: ...
2
votes
1answer
6k views

ps switches to display PID, PPID, PGID, and SID collectively

I tried ps with different kinds of switches e.g. -A, aux, ef, and so forth but I cannot seem to find the right combination of switches that will tell me the Process ID (PID), Parent Process ID (PPID), ...
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2answers
3k views

Zombie process cannot be removed or killed [duplicate]

I have a zombie process that refuses to be removed, have tried killall -9 1913 and pkill with no effect. Any help would be very much appreciated.Running Ubuntu 12.04.2 LTS. Thank you. ...
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1answer
79 views

Are zombie processes something I should be concerned about? [duplicate]

I run a server. Should I be concerned about zombie processes? Do they consume any system resources (RAM, process table entry, etc.) that I should be concerned about?
2
votes
1answer
72 views

Run a script when a process throws stderr message

I want to "wrap" a process around another to catch stderr messages when they occur. Use Case I'm using Compass and I have to have a terminal open and see if there is something wrong. My plan is to ...
1
vote
1answer
157 views

Deadlock in a crontab between cron and its child defunct processes

I'm having a strange case of deadlock, where the two processes launched by cron are defunct, but cron does not pick the return code and exit. I don't have access to the root user. myuser@myserver:~) ...
2
votes
4answers
2k views

How to kill a process which can't be killed without rebooting?

There are 5 processes which can't be killed by kill -9 $PID and executing cat /proc/$PID/cmdline will hang the current session. Maybe they're zombie processes. Executing ps -ef or htop will also hang ...
1
vote
2answers
560 views

“ps” command doesn't return to prompt

I have this linux box that I need to maintain periodically. To do that, I issue a ps command programmatically and check the running processes. But as shown in the screenshot, sometimes, the ps ...
2
votes
1answer
544 views

what is the structure of a linux process? [closed]

what is the structure of a linux process? In linux there are processes executed on a address and which use system resources. Can anyone tell me the structure of a process and which parameter ...
4
votes
1answer
201 views

init: is it a user thread or a kernel thread?

init is the first task executed after kernel is loaded, right? Then who is its owner. also I can see [swapper/0] [swapper/1] ..... [swapper/7] having pid 0 PID PPID CPU TASK ST %MEM ...
5
votes
3answers
321 views

Determining the particular processor on which a process is running

I have access to an 8-core node of a Linux cluster. When logged in to the node, I can see a list of processors using this command: more /proc/cpuinfo In my 8-core node, the processors are numbered ...
4
votes
3answers
4k views

Terminating a bash shell script running in the background

I often use bash shell scripts to run simple commands for many different files. For example, suppose that I have the following bash shell script, called script.sh, that runs the program/command foo ...
2
votes
1answer
464 views

How does One Find the PID of a Process Started with startproc?

My understanding is that it's generally a good idea to create a PID file for daemon processes and that startproc is a good way to start these daemons. I know that startproc takes -i and -p arguments ...
6
votes
8answers
8k views

Bash way to check if a process is already running in the background (and skip re-execution based on that)?

Can I make a bash command line that only runs a certain command if the process is not already running (in the background)? How do I check*, if a command is already running? (so I can add the next ...
3
votes
3answers
4k views

Fix “firefox is already running” issue in Linux

I am trying to open Firefox in CentOS, but I'm getting the following message: Firefox is already running but is not responding and Firefox doesn't open. I tried this in command line: kill ...
15
votes
5answers
2k views

Can ps display only non kernel processes on Linux?

How can I ask ps to display only user processes and not kernel threads? See this question to see what I mean...
5
votes
4answers
179 views

Best practices for job/process tracking and multi-tasking

I run 10+ different commands from 10+ different directories, and I need a better process to track everything. I do a lot of debugging, and often times I need to work on multiple issues in parallel. I ...
1
vote
1answer
173 views

AIX why does ps display the process name between square brackets? [duplicate]

On AIX 7 I have a process whose name appears between square brackets in the ps output: PID TTY TIME CMD 7798784 pts/2 0:00 [myproc] 9044154 pts/2 0:00 ps 10485770 pts/2 0:00 ...
1
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3answers
108 views

How to know if a specific program is open

Using a command line in terminal, I want to be displayed 1 if a program (for example Firefox or Chromium) is open and 0 otherwise. Edit: By "open", I mean "is running on the current machine and has a ...
3
votes
2answers
187 views

Get PID of the application running in the active terminal emulator

My end goal is to be able to open a new terminal window (urxvt) directly in the current working directory of the program running in the window currently active. I'm currently using the shell (Bash), ...
4
votes
1answer
147 views

Raise Brightness When Maximizing Terminal

I'm looking to raise the brightness when I maximize or foreground the Terminal window which has Vim running. I would like to reset the brightness to normal when I minimize or background that process ...
2
votes
1answer
589 views

How to check if a currently running process is opened by root or user

I'm currently creating a BASH script to kill off processes. I first check if the process is running then kill it. But I would like to add a nested if to find out if that process was opened by root ...
5
votes
2answers
538 views

Turning off swapping for only one process with cgroups?

I would like to turn off swapping for only one process. Swap should work as usual for the other processes. How I can implement this with cgroups?
1
vote
2answers
613 views

How do I kill 'repo sync' using crontab given it spawns many processes?

I need to 'repo sync' the Android source overnight, as my monthly bandwidth is limited. , I start the 'repo sync' at midnight, then want to kill it at 8am. The following is the command: 2 0 * * * ...
0
votes
1answer
383 views

Identify Tasks/Process which are 7 days old in linux

How can I identify the processes running since 7 days in Linux?
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1answer
199 views

How to kill all processes that don't have specific parent process?

A parent process should always be running with N children process. I would like to run a script which will show/kill all children processes that don't have a parent process. $ ps faux | grep ...
2
votes
2answers
198 views

process memory usage

What is usually meant by the phrase process memory usage, what does this actually mean, i.e. what does this memory consist of? And what column does it correspond in ps aux output, RSS or VSZ?
4
votes
2answers
207 views

Is grandchild process also child process?

In Unix/Linux terminology, do child processes of a process include grandchild processes of the process?