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

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What's the mechanism that a process listening to localhost refuses to process a request to its LAN IP address?

The private IP address of my machine is 192.168.44.182. If I started a process using nc -l localhost 20000 Then this process won't handle requests sent to 192.168.44.182. Since the process ...
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1answer
191 views

vim not shown in fuser

First use Vim to edit a file, say /tmp/A. Assuming that vim process is the only one that accesses /tmp/A, then use "ctrl+z" to suspend the process, and execute fuser /tmp/A Then you see nothing ...
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How can I find which process sends data to a specific port?

I have a service, keeping a certain port open. I'm getting data to it, that I neither expect nor want to get, and I'm trying to pin-point the source of this data. So how can I find which process that ...
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38 views

Modify environment variable in a running process [duplicate]

Possible Duplicate: change environment of a running process Is there a trick to modify an environment variable in a running process? I need to add a repository at the end of PATH. I have ...
2
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1answer
68 views

remotely query text file associated with an instance of vi

I have opened several text files (a.txt, b.txt, c.txt, ...) in different sessions of vi launched from different instances of a bash shell. Having then accessed that machine remotely, I wish to ...
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2answers
8k views

Get PID of a function executed in the background [duplicate]

#!/bin/bash function abc() # wait for some event to happen, can be terminated by other process { sleep 3333 } echo "PID: $$" abc & echo "PID: $$" I need to retrieve the pid of this function, ...
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4answers
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What's the difference between running a program as a daemon and forking it into background with '&'?

What are the practical differences from a sysadmin point of view when deploying services on a unix based system?
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1answer
11k views

Stuck process: is it a bad sign?

Sometimes a few process are in a stuck state. For example: PID COMMAND %CPU TIME #TH #WQ #POR #MREGS RPRVT RSHRD RSIZE VPRVT VSIZE PGRP PPID STATE 99357 plugin-container ...
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3answers
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What process is sending TCP SYNs on Solaris 10?

Some process on my Solaris 10 machine is sending TCP SYNs to a remote machine. The remote machine never responds, so the connection is not established. How do I find out what process is initiating ...
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2answers
607 views

How to run linux process and come back to it later?

I'm trying to run a minecraft server on linux. Running the server starts an important interactive session. I can run the server in the background by appending & at the end of the command and log ...
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2answers
596 views

How to stop a infinite running process (ztail) started by a ssh session after that session is closed

I have a peculiar problem. My server supports multiple ssh session simultaneously, so that multiple admins can manage (via command line interface) it simultaneously. We have a command which calls ...
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5answers
12k views

Is there a program that can send me a notification e-mail when a process finishes?

I am a computational scientist, and I run a lot of lengthy calculations on Linux. Specifically, I run molecular dynamics (MD) simulations using the GROMACS package. These simulations can take days ...
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3answers
906 views

Why does a default Linux installation run more processes than a default OpenBSD installation?

If I ps -aux on Ubuntu (or any GNU/Linux distribution) without GUI I see ~100 processes running. If I ps -aux on OpenBSD without GUI, then I get ~10 processes. What is the explanation/reason for ...
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4answers
281 views

“Virtual” shell, ie. jailing an user inside a process after the (SSH) login

The title might not say much about the issue at hand so let me get straight to the point. Let's assume I have a casual user who can log in to the system via SSH into a bash shell. I also have a PHP ...
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1answer
204 views

Is there any way to attach latrace to an already-running process?

I want to trace a running multi-threaded process's library calls. As of 5 November 2012, there's only one way to get ltrace to fully support tracing multi-threaded processes: you must check out and ...
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3answers
7k views

How to tell who is connected via vnc to my machine?

How do I check how many vnc connections or different users are currently connected to my machine? Only through wireshark? And how do I kill any other users connected through vnc?
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2answers
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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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1answer
892 views

Korn shell timeout/kill script

I am trying to write a simple Korn shell script to execute a loading process. The process occasionally runs into connectivity issues, so I need to kill it if it runs too long. I have been trying the ...
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1answer
9k views

Understanding ps elapsed time format for long running processes

I'm using a ps command as part of an exercise to identify processes running longer than a given threshold. I'm using the following template to get the elapsed time for a know process command: ps -eo ...
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2answers
274 views

How to kill a process giving it a number of seconds before a doing the forced kill?

I do have the PID of the process to be killed but I do want to give it the chance to die peacefully, without doing a -9. Expected behaviour: check if PID is still running for up to ten seconds and do ...
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1answer
828 views

Files bigger than max(off64_t) on Solaris, eg “/proc/../as”

How do I read or seek from a file that's bigger than the maximum off64_t? The problem arises because the address space of a process is represented in the /proc/.../as file, which is a huge sparse file ...
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1answer
1k views

When do jiffies increment? How a process runs in a jiffy?

I know that jiffies length is selected at kernel compile time and it is defaulted to 250 (4ms). Source: man 7 time - The Software Clock, HZ, and Jiffies I wonder what happens inside a jiffy. What are ...
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root owned program with setuid bit on

Ping is a a program owned by root with the user id bit set. $ ls -l `which ping` -rwsr-xr-x 1 root root 35752 Nov 4 2011 /bin/ping As I understand it, if a user runs the ping process, then the ...
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7answers
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Kill many instances of a running process with one command

This is one of the questions that has troubled me often. Suppose I have thousand or more instances of any process(for e.g. say the process vi) running. How do I kill them all in one single shot/one ...
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4answers
170 views

How to find out what is this process for?

I have this 'java' process running for 3 hours ( I guess ). I didn't see it before and I wonder how could I find out where it's coming from? Here is a screenshot: EDIT: ok I figured it out, it's ...
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Silently start task in background

I know that you can use this to start a process in the background, without getting the notification when the process is put in the background and when it is done like so: (command &) &> /dev/null ...
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1answer
2k views

What is the advantage of using pthreads in Linux?

I read somewhere that Linux threads are really implemented as processes in the kernel since with today's hardware and on the Linux platform, the thread model is inefficient compared to the process ...
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Can I get WCHAN from ps on Mac OS X 10.7.4?

From the manual it seems that ps -AO wchan should tell me what everything is sleeping on, but everything comes up as -. (And nwchan as 0). Did they do away with the old sleep()/tsleep() interface in ...
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3answers
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How to poll existence of a background script correctly

I have a problem with the following kind of script: #!/bin/sh long_running_script.sh & while [ `pidof long_running_script.sh` ] do echo "." sleep 1 done The sript will ...
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2answers
2k views

Find the PID of top CPU/MEM usage, save to a shell variable

Is there any way to get the PID of the top CPU/MEM usage, I need to use that in a script, top command doesn't seem to work for it.
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1answer
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Negatives of running processes with real-time priority?

The question is as the title says, are there any downsides of running processes with real-time priority (chrt -f 99)? My hypothesis is that this combined with an affinity will ensure that any ...
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357 views

Where can I see the processes running at startup?

I'm using backtrack5 R2 and sometimes when I log in the information showed says that There is 1 zombie process, where can I see what process is running?
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5k views

Find processes using a network interface

I'm trying to find a way to safely shutdown a network interface, i.e. without disturbing any processes. For this I need to find out what processes are currently using that interface. Tools like ss, ...
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3answers
527 views

Prevent users from killing processes that they own

I have started some processes (window based) from user's .bashrc file. I want to prevent users from killing those processes. Is there a way to transfer the process to superuser so that a normal user ...
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1answer
4k views

How to know maximum memory usage of a process? [duplicate]

Possible Duplicate: Measuring RAM usage of a program I have a process, which is quite short-running (about 10 minutes), but memory heavy. I want to know how much memory does the process ...
3
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1answer
1k views

How do I detach a process from its parent? [duplicate]

Possible Duplicate: How can I disown a running process and associate it to a new screen shell? The problem is that the process is not a job inside of my active shell (as I've logged in from ...
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1answer
870 views

What process created this window with no PID associated? [duplicate]

Possible Duplicate: What process created this X11 window? I need to kill a process that spawned a window which seems to have no PID associated with it. At least that is what xdotool says: ...
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2answers
170 views

How to constrain the resources an application can use on a linux web server

This is the situation: I have a PHP/MySQL web application that does some PDF processing and thumbnail creation. This is done by using some 3rd party command line software on the server. Both kinds of ...
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0answers
159 views

How to find current chroot jail path on Linux <2.6.26

While running kernel 2.6.26 or newer it's possible to get the path of the current chroot jail by comparing the mountinfo of the current process and the init process. Is there a way to get the same ...
2
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1answer
554 views

How to log processes in daemon-mode?

I would like to save the standard output of the program motion in a text file. If I don't use motion in daemon-mode I would simply do it by: motion > log.txt But what is the equivalent when I ...
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2answers
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`[java] <defunct>` with defunct children -> Any way to collect them?

Relating to question : What if 'kill -9' doesn't work? I have following situation : zombie process with threads, not collected by init : [root@Arch64]# ps auxH | grep java gwpl 569 ...
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1answer
4k views

mmap() failed: Cannot allocate memory - how do I find out who's complaining?

mmap() failed is popping up in my .xsession-errors in bursts. But there's no indication about what application it is failing with. How do I look into this after it has happened? I usually discover the ...
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3answers
374 views

Where to find explanation of kernel processes?

I want to know about kernel processes, like [migration], [kswapd], etc. Where are kernel processes like these documented?
5
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2answers
1k views

Why is `sudo pkill -HUP -f “nginx: master process”` returning code 129 and no output

I'm trying to trigger a reload of the Nginx master process by using pkill and sudo. The server reloads fine, but I was just curious if anyone knows why the command sudo pkill -HUP -f "nginx: master ...
3
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2answers
938 views

wait does not wait

If i have a file called myprogram containing sleep 200 date Run this in the background: $ sh myprogram & i want to know when myprogram has completed by using wait command $ cat >notify ...
14
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3answers
2k 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 ...
0
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1answer
406 views

Giving input to background processes

Is there any way to give input to background processes or which run as daemon processes? I was coding some Puppet configuration files and I had to push them to some remote machine. For that purpose I ...
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2answers
3k 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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4answers
7k views

Save entire process for continuation after reboot

I developed an algorithm for a fairly hard problem in mathematics which is likely to need several months to finish. As I have limited resources only, I started this on my Ubuntu 12.04 (x86) laptop. ...
5
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1answer
3k views

Difference between poll_s and ep_poll WCHAN in ps output

When I issue ps -elf|grep python for example on my system, I see these: 1 S 1000 6020 6008 0 80 0 - 9914 poll_s Jul12 ? 00:00:01 python manage.py run_gunicorn -t 3600 -w 8 -b ...