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

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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 ...
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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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Print pids and names of processes as they are created

From the question here, the OP wants to repeatedly poll the pid of a process using pidof in a shell script. Of course this is inefficient as a new process must be started for the pidof program ...
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when does the system send a SIGTERM to a process?

My server program received a SIGTERM and stopped (with exit code 0). I am surprised by this, as I am pretty sure that there was plenty of memory for it. Under what conditions does linux (busybox) send ...
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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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Is it possible to know the source (application) of the clipboard?

I've noticed that sometimes clipboard contents become unavailable if the source application (where the content was copied from) is closed. This leads me to wonder if it's possible to know what the ...
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New parent process when the parent process dies

In UNIX, when a parent process disappears, I thought that all child processes reset init as their parent. Is this not correct all the time? Are there any exceptions?
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monitoring file changes + process access to files

I would like to see what's happening in my app server folders, which files are changed by process x or which *.war files has been changed (replaced/created) in last x minutes. I am software developer ...
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Drop Process Privileges

I have a process that gets started by a damon running as root, now I want to "downgrade" this process's privileges to those of your average user. Is this possible? If yes how? PS: Running unix on a ...
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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 ...
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Launch process as another user/group (in init.d script)

I am editing a init.d script. The init.d script runs a utility script which then runs an process. From either bash scripts how would I make it launch the main process as a specific user and group?
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Why does “kill -9 0” end my console session?

I just wonder why kill -9 0 ends my tty console session? What exactly is PID 0, it is not listed on a ps aux?
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Alert when running process finishes

There are a few questions and answers on here with regard to being alerted when a process completes/exits(1, 2) – but these all assume that the user has issued said process themselves, and thus can ...
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How can I tell when a process has finished writing to a file?

I have a process which has been spawned from a shell. It is running as a background process and exporting a DB to a CSV file in /tmp. How can I tell when the background process has completed ...
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Harddrive I/O per Pid

is there any way to see the disk I/O per pid/process ? Monitorix shows me the following and correct me if I´m wrong, but it looks like that the harddrive is slowing down the whole system: UPDATE #1 ...
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Execute Nohup command with input

In UNIX, I have a process that I want to run using nohup. However this process will at some point wait at a prompt where I have to enter yes or no for it to continue. So far, in UNIX I have been doing ...
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What three files are always opened by a process?

Someone mentioned that there are three different files that a process always opens. What does this mean? What files are they?
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What's the purpose of the /proc/pid/mountinfo file?

What's the purpose of the /proc/pid/mountinfo file (with pid being numerical process id)? As far as I can see it reflects contents of the /proc/mounts file but with added information. Also the file ...
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Simulate an unkillable process in D state

For catastrophe testing scenarios on out server environment we're looking for an easy way to make a process stuck in D (uninterruptible sleep) state. Any easy ways? An example C sample code would be ...
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Finding out with which parameters a program was started

Is there a way to find out for any given process with which parameters it was started?
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Dump process core without killing the process

Is there a way to get a core dump (or something similar) for a process without actually killing the processes? I have a multithreaded python process running on an embedded system. And I want to be ...
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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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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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Understanding top and load average

I'm observing a high load average on a certain machine (about 9) in all three load fields. I understand load as the number of processes in state "run" / currently desiring CPU time. Am I correct at ...
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How to find tty from which a particular cmd “scp” is executed

How can I find out who executed a particular command and which terminal was used to run it? Original: How can I know particular cmd is executed by whom and to know about my terminal
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Real time priorities in non real time OS

If I do the following command on my standard Linux Mint installation: comp ~ $ ps -eo rtprio,nice,cmd RTPRIO NI CMD ... 99 - [migration/0] 99 - [watchdog/0] 99 - [migration/1] - 0 ...
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ATOP shows red line vmcom and vmlim. What does it mean?

utility atop shows: ATOP - MyServer 2013/01/07 00:03:57 10 seconds elapsed PRC | sys 2.18s | user 8.33s | #proc 141 | #zombie 0 | #exit 0 | CPU | sys 21% | ...
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What should interactive shells do in orphaned process groups?

(Re-posting in unix per the suggestion in http://stackoverflow.com/questions/13718394/what-should-interactive-shells-do-in-orphaned-process-groups) The short question is, what should a shell do if it ...
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Is the sum of all PIDs “utime” the total system utime?

In order to measure a user's total CPU time, I'm using the "utime" field out of /proc/[pid]/stat: utime %lu Amount of time that this process has been scheduled in user mode, measured in ...
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Threads vs (Forked) Processes

Linux applications generally fork then exec (with execve() ), but Java applications, and certain Apache MPMs use threading. If forking, uses the fork + exec to spawn a process, what is the high level ...
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chdir(<directory>) doesn't change directory after exiting to shell

I wanted to make a simple C program to change to my project directory. Its content is as follows: #include <unistd.h> int main() { chdir("/home/enedil/projects/algo"); return 0; } I ...
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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 ...
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Portability of file descriptor links

I've always wondered this but never took the time to find out, so I'll do so now - how portable is the usage shown here of either /proc/$$/fd/$N or /dev/fd/$N? I understand POSIX guarantees /dev/null, ...
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How to determine what instructions a process is executing?

I know about strace and ltrace, but that only tells me what system calls and library calls a process is executing, respectively. I would like to know exactly what instructions a process is executing. ...
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How can I see what processes are running?

I use Ubuntu Server 10.10 and I would like to see what processes are running. I know that PostgreSQL is running on my machine but I can not see it with the top or ps commands, so I assume that they ...
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How can I start a process with any name which does nothing?

I want to start a process that does nothing but is still running. Say I start a process called sadhadxk, and when I run pgrep -x "sadhadxk" I will get the PID number back, like any normal process ...
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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 ...
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How to stop a bunch of processes on unix fast?

How to stop a bunch of processes on unix fast. I can use ps/top, kill. If the number of processes is very large, I use shell script. Are there other ways, only one or two unix commands can do it ...
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In bash script, how to capture stdout line by line

In a bash script, I would like to capture the standard output of a long command line by line, so that they can be analysed and reported while initial command is still running. This is the complicated ...
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Kill only one Java process

I usually run few Java applications, one for server running locally and other for some IDE like NetBeans. And from time to time, after lots of redeployments, my server get stuck on ...
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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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How do Linux permissions work when a process is running as a specific group?

This is something I haven't been able to find much info on so any help would be appreciated. My understanding is thus. Take the following file: -rw-r----- 1 root adm 69524 May 21 17:31 ...
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Is it possible to get process group ID from /proc?

In "http://stackoverflow.com/questions/13038143/how-to-get-pids-in-one-process-group-in-linux-os" I see all answers mentioning ps and none mentioning /proc. "ps" seems to be not very portable ...
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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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Dynamic file content generation: Satisfying a 'file open' by a 'process execution' [duplicate]

I have a read-only file, F. A program, P, that I'm not the author of, needs to read F. I want the content of F to come from another 'generator' program, G, whenever P tries to read F (taking F to ...
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If I see a process running using ps, how can I find the executable?

If I can see a process running using ps -e, how can I find the file which launched it?
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What does <defunct> mean in the output of ps?

I had issued the ps -ef|grep java command and this is one of the entries that I got : subhrcho 875 803 0 Jan23 pts/5 00:02:27 [java] <defunct> What is <defunct> implying here ? ...
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Difference between owner/root and RUID/EUID

I am relatively new to the concepts mentioned in the question and reading about them from different sources only makes them more confusing. So this is what I understood so far: When we are given ...
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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 ...
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How to check which process is using most memory

When I check free in one of Prod server it showing 70% of memory is being used: total used free shared buffers cached Mem: 164923172 141171860 23751312 ...