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

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Is reparenting from the shell possible?

This question is closely related to How to "correctly" start an application from a shell but tries to tackle a more specific problem. How can I spawn an application from a shell and thereby ...
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0answers
14 views

Terminal output from a program not opened in terminal [duplicate]

Using bash on Ubuntu, I can launch programs from command line and watch what the program is doing 'in the background' while I use the GUI frontend. This is particularly handy when a GUI progress bar ...
9
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3answers
32k views

Alternatives for “lsof” command?

In many cases "lsof" is not installed on the machines that with I have to work, but the "function" of lsof would be needed very much (ex. on AIX). :\ Are there any "lsof" like applications in the ...
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1answer
29 views

Using $BASHPID in grep statement

I'm trying to exclude the PID of the subshell from the results returned by pgrep. Note that the name of the file is the same as the name passed to pgrep. Why does setting a variable equal to BASHPID ...
1
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1answer
40 views

How can I determine what individual ulimit constraint a process has?

I have a service that sets a custom limit for open files (ulimit -n 5000) as part of its init script. My understanding is that this will be effectively for the service and its child processes. Since ...
8
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2answers
315 views

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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2answers
41 views

If I use one of the exec family functions to open a child process, will pipes to parent be applied to the child?

Say I open a parent process with a master process that assigns the stdout to a file for logging. Then say I use the parent process to open a child with execvp (or any other of the exec family of ...
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1answer
55 views

What are the potential negatives of turning on process accounting (psacct package)?

I am looking into turning on process accounting on some EL6 servers. What are the potential pitfalls of turning this on? If you mitigate storage requirements with log rotation, any reason you would ...
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3answers
85 views

Run linux process at very very low priority?

I have regular process that not so important but will consume so much CPU power, and I have another process which is really important, but it spend most of the time idle, but when it got a job it ...
2
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0answers
57 views

How to run the dialog command with proccess? [duplicate]

NOTE: Please look at my code, it's a Bash script. I want to display both dialogs on the screen at the same time, one dialog displays this: tail –f from - /var/log/proccess1.log and the second ...
0
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1answer
28 views

Background Process not running?

I ran a C program with an infinite while loop in a terminal and observed one of the CPU cores shot to 100% usage. When I turn it into a background process using Ctrl+z, the CPU usage suddenly dipped ...
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1answer
50 views

Deterministic method to find out whether some other process is in a chroot jail and where?

NOTE: I'm familiar with this U&L Q&A titled: How do I tell I'm running in a chroot? that sounds similar to what I'm asking, but there's a subtle difference to what I'm looking for. That ...
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1answer
32 views

Empty kernel processes on CentOS vps : 2 different servers

I'm not sure I'm asking correctly, or perhaps I'm just looking at the wrong things. I'm migrating from one CentOS Vps (on an OpenVZ box) to another CentOS VPS (on a VMWare box). VPS #1 = CentOS ...
4
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1answer
51 views

How can process doing “vfork without exec” end up in a long uninterruptible sleep?

In this answer user suggests that Normally, Uninterruptible sleep should not last long, but as under windows, broken drivers or broken userpace programs (vfork without exec) can end up sleeping ...
5
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2answers
382 views

Why does process substitution result in a file called /dev/fd/63 which is a pipe?

I am trying to understand named pipes in the context of this particular example. I type <(ls -l) in my terminal and get the output as, bash: /dev/fd/63: Permission denied. If I type cat <(ls ...
4
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1answer
83 views

How to completely detach a process

I want to spawn a process and run it at the top level so that when the shell exits, the process keeps running. I had mistakenly thought that nohup would do this, but when I exit from the shell (the ...
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3answers
12k views

How to kill a daemon with its name gracefully?

I usually kill a process with killall. killall markdoc But I am not sure if this command terminates the process gracefully. Does this command achieve graceful termination? If it does not, how can ...
5
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1answer
116 views

Is the Unix process scheduler itself a process?

Is the Unix process scheduler itself a process, or does it piggyback on other processes in the same way a system call does (running kernel code in the user process with the kernel bit set)?
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1answer
53 views

Comparing Windows and Linux machine hardware

I have to compare Linux and Windows machine hardware? In windows system, I can open the My computer properties and see the details like processors, RAM Hard disks etc. Through task manager, I can see ...
9
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1answer
220 views

Why does the location of Enviroment Variables vary that much?

Reading the book Hacking: The Art of Exploitation by Jon Erickson, I am trying to approximate the address of an environment variable SHELLCODE to exploit a program. Every time I run ...
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2answers
50 views

Process auto starts itself not by cron

My linux server was hacked. and now there is a file in root directory that generates big traffic. when i kill this process it autostarts itself again. then i did chmod -x. but it returned x option. ...
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1answer
62 views

How logical address of one process differs from the logical address of another?

I am a newbie. I am reading Understanding Linux Kernel. There, I am trying to understand how logical address got translated to physical address. To my understanding, I believe logical address got ...
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1answer
51 views

Which process scheduling algorithm is used by Linux?

The Linux operating system switches between running processes to enable multi-tasking. What algorithm is used to determine when to suspend the execution of the currently running process and which ...
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1answer
242 views

Real time processes scheduling in Linux

I have been learning some scheduling concepts. Currently my understanding so far is as below. There are real time processes and non real time processes. Non real time processes can have nice values ...
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0answers
36 views

API Monitoring and Hooking

I am currently reading the "Malware Analyst's Cookbook and DVD". There is a chapter "Dynamic Analysis" and there are also some recipes about hooking and monitoring API calls of process but it is for ...
2
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1answer
61 views

strace works for some builtin commands

I'm trying to understand some kernel level concepts in Linux. I was checking on the difference between shell builtin commands and the other executable commands. This wonderful answer clearly tells ...
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1answer
238 views

per process private file system mount points

I was checking unshare command and according to it's man page, unshare - run program with some namespaces unshared from parent I also see there is a type of namespace listed as, mount ...
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1answer
47 views

Preserve evidence of intrusion / deleted executable?

If you are faced with a non-root remote command execution vulnerability, and there is a foreign executable that's running on your Linux system from a user with only non-administrator privileges, ...
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1answer
69 views

How disk IO priority is related with process priority?

I'm running software that overloads disk IO sometimes. I don't need fast response from that software, I need fast response from other applications, so I could set low process priority for that. I want ...
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3answers
278 views

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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1answer
45 views

Does “stopped” belong to “blocked” state?

The manpage of ps says PROCESS STATE CODES R running or runnable (on run queue) D uninterruptible sleep (usually IO) S interruptible sleep (waiting for an event to complete) Z ...
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1answer
248 views

why “ps -ef -u root -U root” also displays user processes?

ps -ef -u root -U root Also displays processes whose user is not root (the current user). Can someone explain me why ? -u : EUID -U : RUID
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3answers
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How to check how long a process ran after it finished?

Currently I'm using the following to check how long a process is actually running: ps -eo uid,pid,etime | egrep '^ *MY_ID' | egrep 'PID_OF_PROCESS' And that outputs the following: MY_ID ...
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2answers
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cpulimit does not detect Node.JS process

I was able to limit python process to use only 50% CPU with the following cpulimit -l 50 -e python but when I tried to do the same for Node, and it is not able to detect the process at all. Does ...
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5answers
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view stdout for another pts

Here is the situation. I left my pc at home doing an rsync from a 2TB hard drive to another 2TB hard drive (it's going to take a while since they are both USB 2.0). I am now at work and I have ssh-ed ...
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2answers
866 views

How to find out what process is writing to STDOUT?

I have two instances of a process running. One of them is "frEAkIng oUT!" and printing errors non stop to STDOUT. I want to kill the broken process but I have to make sure I don't terminate the wrong ...
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1answer
83 views

Process status on AIX

I want to get process status on AIX like we get it on Linux from /proc/<PID>/stat, I did not find the status in /proc/<PID>/status file. There was some encrypted text there. Which file ...
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39 views

Is killing processes created on startup safe?

I've just got a vserver running debian 7 and whenever I start the server and call the top command, there are very many processes that were started automatically on startup. Can I kill them or are ...
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2answers
516 views

find out the memory allocated for a particular process in ubuntu

Could anyone please tell me how to find out the memory allocated for a particular process in ubuntu?
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0answers
40 views

How is user space process/thread controlled by the operating system

I understand this: User code executes in a process/thread context in a process address space, in user mode, and can address only user code/data defined for the process, with no access to privileged ...
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2answers
207 views

How to kill a process running in specific script

I have two script files running simultaneously. I just need to kill the java process running in one script without affecting the java process in the another one.
2
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1answer
56 views

Process IDs range

On GNU/Linux system I seen only positive PIDs, but when kernel panic occured I seen info about process with PID=0. What's it? On Minix 3 I seen processes with negative PIDs. Minix is POSIX-compatible ...
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8answers
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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 ...
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3answers
129 views

How can I get the pid of a process started this way

#!/bin/bash mkfifo /var/run/out while true do cat /var/run/out | nc -l 8080 > >( while read line do do some stuff done ) done How can I get the pid ...
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4answers
117 views

Prevent a second instance of my software from starting

I wrote a service script to run a specific software at boot time. How can I restrict this software so that it does not run manually again? I mean software has to have just one instance in the ...
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0answers
34 views

How to start Process state

Over and over and also aver again. I saw this picture on operation system text book. But this time, I want to see the codes to understand this picture more tangible. where is codes which their duty ...
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1answer
317 views

How can I kill child processes with start-stop-daemon?

I'm writing a simple web server using nc and bash. It looks like this: #!/bin/bash rm -f /var/run/streamman/out mkfifo /var/run/streamman/out trap "rm -f /var/run/streamman/out" EXIT while true do ...
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2answers
134 views

kill xterm process in a bash

I would like to kill the xterm process I started this way in a script: #!/bin/bash echo "#!/bin/bash" > /tmp/test0 grep file | awk '{print "xterm -hold -e echo",$1,"sleep 10" && pid=$!}' ...
6
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3answers
4k views

killall gives me `no process found ` but ps

Could somebody explain to me the difference between kill and killall? Why doesn't killall see what ps shows? # ps aux |grep db2 root 1123 0.0 0.8 841300 33956 pts/1 Sl 11:48 0:00 ...
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2answers
128 views

Detecting kernel thread on pre-3.0 kernels

Looking at the proc man page (http://man7.org/linux/man-pages/man5/proc.5.html) it is possible to detect which processes are kernel threads in /proc/<pid>/stat by looking at the flags value ...