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

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How to terminate a background process in Linux when the pid is unknown?

I have a job dispatcher bash shell script containing below codes: for (( i=0; i<$toBeDoneNum; i=i+1 )) do while true do processNum=`ps aux | grep Checking | wc -l` ...
13
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1answer
4k views

How to tell if a running program is 64-bit in Linux?

In Mac OS X, I could use the Activity Monitor program to see if a running program/process is 64-bit. How do I do that in a Linux OS, regardless of flavour?
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2answers
2k views

Detailed Per-Process Profiling

I am looking for a way to profile a single process including time spent for CPU, I/O, memory usage over time and optionally system calls. I already know callgrind offering some basic profiling ...
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1answer
173 views

root permission denied on /proc/1/exe

I just performed a fresh ubuntu install and i am seeing the following in lsof: userA@az1:~$ lsof COMMAND PID TID USER FD TYPE DEVICE SIZE/OFF NODE NAME init 1 ...
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1answer
130 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 ...
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556 views

Is it possible to support multiple processes without support for Virtual memory?

Is it possible to support multiple processes without support for virtual memory? I would like to know more about it if so.
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1answer
98 views

moving from user mode to kernel mode

I read the following: "All processes begin execution in user mode, and they switch to kernel mode only when obtaining a service provided by the kernel." When it says "obtaining a service ...
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3answers
205 views

Why is I/O uninterruptible?

What is the rationale behind making I/O uninterruptible? What would be the negative consequences if a process handling I/O were allowed to handle a signal?
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1answer
302 views

How to check the status of bash shell script while executing from Python script?

I have a simple Python script which will execute a shell script using subprocess module in Python. Below is my Python shell script which is calling testing.sh shell script and it works fine. import ...
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1answer
219 views

How can I track executables created by my user on Linux?

Using Linux, I would like to track the executables that are executed in my name, including the whole command line (in practice, every exec*() done as my own user). A program I do not control is ...
13
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1answer
2k views

per process swapiness for linux

/proc/sys/vm/swappiness is nice but i want a knob that's per process like /proc/$PID/oom_adj so that i can make certain processes less likely than others to have any of their pages swapped out unlike ...
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318 views

Kill user processess on logout

I have a Ubuntu server that handles remote X sessions from users. However, I don't want to allow users to run any kind of background processes - so here is my question: How do I prevent users from ...
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3answers
123 views

Detect process if not found then run it

I am running several process at startup using "crontab -e" @reboot tranmission-daemon && python defualt.py && python MonitorService.py But for some reason, those service can ...
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2answers
188 views

Finding the PID of the process using a specific port?

I am installing hadoop on my Ubuntu system. When I start it, it reports that port 9000 is busy. I used netstat -nlp|grep 9000 to see if such a port exists and I got this: tcp 0 0 ...
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1answer
118 views

How does the piping in this command ultimately achieve to kill the process?

I have seen the following line in a bash script for killing a process(in this case started with the command loadgen): ps xww | grep -i "loadgen" | grep "PATTERNMATCH_FACT.xml" | cut -c1-5 | xargs -i ...
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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...
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1answer
67 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?
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2answers
646 views

Removing zombie process from the process table

Can somebody please explain when parent process receives the exit status of a dead child process via wait, who actually reallocates the memory of the child process and removes it from the process ...
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2answers
528 views

Is there any impact of reaping zombie processes?

I will execute following command for reaping zombie /usr/bin/preap $(ps -ef | grep defunct | grep -v grep | awk '{ print $2 }' | xargs) Is there any service impact of this approach ?
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4answers
812 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 ...
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3answers
486 views

Is there a way to identify which process turns into Zombie process

One of the ubuntu server has 82 zombie processes. All processes shows '[sh] defunct' as process command. Is there a way to find out which process is becoming a zombie process? I tried checking the ...
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2answers
804 views

Is there an upper limit to the number of zombie processes you can have?

I used to work with an HP-UX system and the old admin told me there is an upper limit on the number of zombie processes you can have on the system, I believe 1024. Is this a hard fact ceiling? I ...
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1answer
350 views

What is a zombie process? [closed]

Could you tell me the meaning of a "zombie process" and give an example.
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185 views

Why Process/program becomes zombie?

If script is running fine from command line then, why the same script becomes zombie state after running through cron and How you will troubleshoot the same ? Here following real example : [root@abc ...
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3answers
200 views

How do I wait on a program started in another shell

I have a program that does a large a amount of work (takes about 4-5 hours) that gets started by cron when all the data it works with becomes available. Sometimes, when I am waiting for it to finish, ...
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3answers
140 views

Locate a directory from a relative path in ps output

When I executed the command to give the pid of my processes running, it gave me like this - user@machineA:/$ ps -eo pid,command | grep exhibitor | grep java | grep -v grep 1615 java -jar ...
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2answers
231 views

How can I create a hard to kill process

I want to create a program that will be difficult to stop (even for the administrator) once it is started (with root privileges). Once started the process should continue to start itself at startup ...
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3answers
1k views

How to stop a background process?

I have started a wget on remote machine in background using &. Suddenly it stops downloading. I want to stop its process, then start it again. How can I stop it? I haven't close its shell window. ...
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4answers
2k views

Is it possible to find the path of a running program?

I have a xmms2d process running, but two possible executable files (in different directories, both in the executable path) that could have spawned it. I suspect that one of those is corrupted, because ...
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2answers
82 views

Why do I see more processes in KVM than in OpenVZ?

I've got a 512mb Centos 6 VPS running on KVM. Now another VPS from a org. I manage is running on OVZ. When I type top on the KVM one, I get a whole list of all sort off processes. But when I do this ...
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86 views

Owner of init and xterm

I don't understand what is owner of process. Owner of bash is me. Then who is owner of init and xterm? I searched on google but I can't find.
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107 views

How do I draw a process tree from my shell to the kernel?

I can't understand this problem For each process in the tree, indicate the name of the process, the process's ID number, and the name of the owner of the process.
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0answers
107 views

How to get start time for a defunct process on AIX?

When I run the following commands on AIX: 22:root@SERVER:/root # ps -ef | head -1 UID PID PPID C STIME TTY TIME CMD 22:root@SERVER:/root # ps -ef | grep defunct | head -1 ...
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377 views

Need for thread_info structure in Linux 2.6 Kernel

Prior to the Linux 2.6 kernel, struct task_struct was present at the end of the kernel stack of each process. There was no thread_info struct concept. But in Linux 2.6 kernel, instead of task_struct ...
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1answer
112 views

Grep Wvdial output while it is running

I want to grep the output from wvdial while wvdial is running. Actually I want to fire a task when the modem is connected. I want to do this in the following way: grep string "IP address", if it is ...
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2answers
138 views

Why are there so few “running” processes?

On all of BSD/Linux/MacOS and Solaris, I made an observation - no matter how busy the system is, top always reports very few (usually 1-2) running processes. According to my limited understanding, a ...
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2answers
166 views

How can I allow a user to prioritize a process to negative niceness?

I want a user to run a specific process on the system with a negative nice value. I can't simply fork the process to background as this specific program is a minecraft server and I rely on the command ...
6
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4answers
877 views

How do I start a process with a nice value of -20 and not give it root privilege?

I would like to start a process with a nice value of -20. This requires me to use a command like - sudo nice -n -20 matlab. However, this starts matlab as root too. Is there a way to have matlab as ...
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4answers
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How can I get a full process list in solaris, without truncated lines?

Is there a way to generate a full process listing in solaris, without truncated lines? I've tried the ps command, with the following arguments: -f Generates a full listing. ...
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1answer
109 views

Which system calls could create a new process?

When executing ps command in my Linux system i see some user processes twice (different PID...). I wonder if they are new processes or threads of the same process. I know some functions in standard C ...
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227 views

Using `kill -s 0 $pid` vs `[[ -e /proc/$pid ]]` to detect if PID is running

One of the idioms often used to check if process is running is to use kill -s 0 $pid. My question is, does it have any upsides over using [[ -e /proc/$pid ]] construct? The script I'm writing is ...
21
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3answers
932 views

If computers start counting at 0, why does the init process have a pid of 1?

Not much to put here in the body, the question is self explanatory.
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1answer
76 views

Difference between process in background and daemon [duplicate]

What is technically the difference of a process that started in foreground and was manually put into background and a daemon? Do they have different properties?
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2answers
94 views

Is it possible to control xterm (or specifically a process that xterm has started) from another process?

If I start a process with xterm like this (where omxplayer is the process xterm is starting): xterm -fullscreen -fg black -bg black -e omxplayer -o hdmi -r %f Is it possible for me to write to ...
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1answer
54 views

What is the rtsbpp-polling process doing?

In Ubuntu 12.04 LTS when I run the top command I see a process called rtsbpp-polling. Googling it gives only just a few hits to the Gentoo Linux forum that does not seem to be relevant (they don't ...
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3answers
202 views

How can you change the process name of Wing IDE from python to something more descriptive

In my process list under Ubuntu (using top/System Monitor) one of the largest memory hogs (200+Mb) was python. I searched a bit for one of my programs to be the cause until I realised this was my ...
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0answers
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How to send a running process to jail?

"Go directly to jail; do not pass go, do not collect $200" — Monopoly Is there any way to make a running process's all future file access behave as if it has always been in a chroot environment?
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How to check, which limit was exceeded? (Process terminated because of ulimit. )

Let's assume process runs in ulimited environment : ( ulimit ... -v ... -t ... -x 0 ... ./program ) Program is terminated. There might be many reasons : memory/time/file limit exceeded ; just ...
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What information about a process is retrievable after it is terminated? [duplicate]

After a process has been terminated, is it possible to retrieve any information about it, such as when it started and finished, &c. Is it possible to enable logging of this information?
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153 views

AIX open() : file descriptor is zero (!?)

A daemon process, on detecting the presence of a text file in a particular directory then launches an executable file which opens the aforementioned text file in order to read and then transmit its ...