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

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5answers
9k views

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 ...
0
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2answers
60 views

How to start a process from the shell and make it the child of another process

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 ...
2
votes
2answers
31 views

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 ...
12
votes
2answers
750 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 ...
1
vote
1answer
18 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 ...
0
votes
2answers
34 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 ...
2
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2answers
50 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?
0
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0answers
16 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 ...
0
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2answers
75 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
37 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 ...
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 ...
0
votes
3answers
88 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 ...
1
vote
4answers
71 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 ...
0
votes
0answers
29 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 ...
1
vote
1answer
63 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 ...
2
votes
1answer
32 views

where is PCB on linux

PCB is process control black , this is its definitions on Wikipedia Process Control Block (PCB, also called Task Controlling Block,[1] Task Struct, or Switchframe) is a data structure in the ...
1
vote
2answers
889 views

Discrepancy between reported used memory and sum of application memory usage

I'm running a desktop system that quite regularly suffers from lack of memory, this prompted me to investigate what causes the issue in the first place. Problem is, there's no single process that ...
1
vote
2answers
41 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
votes
3answers
3k 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 ...
2
votes
2answers
88 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 ...
6
votes
4answers
337 views

Send SIGINT to child process of shell, simulating CTRL+C (Linux)

Given a shell process (e.g. sh) and it's child process (e.g. cat), how to simulate the behavior of CTRL+C using the shell's process ID? This is what I've tried: Running sh and then cat: ...
0
votes
1answer
58 views

Are lock, mutex, and semaphore for between threads or between processes?

I think lock, mutex, semaphore are used for synchronized multiple (threads or processes?) to access something simultaneously. Must this "something" be some shared memory between multiple (threads or ...
3
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3answers
53 views

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?
4
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1answer
52 views

Get CPU usage for single process

I've got a problem getting a real-time CPU usage of a single process (by its PID). I'd like to setup a watchdog for the CPU usage of a process because it's suddenly reaching 100% of the CPU usage ...
5
votes
2answers
2k views

How do I tell a script to wait for a process to start accepting requests on a port?

I need a command that will wait for a process to start accepting requests on a specific port. Is there something in linux that does that? while (checkAlive -host localhost -port 13000 == false) ...
0
votes
2answers
25 views

moving a process to fg and bg [duplicate]

Suppose I run a process in the background likw ./script &, I can bring it to foreground by running fg. However, is there a way to move it back to background without stopping it (as in ctrl+z) or ...
0
votes
1answer
29 views

Restarting process via cron every 12 hours

I'm not familiar with cron at all, and I've looked it up and am still confused as to how specifically it works. I'm on CentOS 6.5, and I need to end a process and then start it again every 12 hours. ...
0
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0answers
6 views

What does the following code do? [migrated]

Including the initial parent process, how many processes are created by the program: #include <stdio.h> #include <unistd.h> int main() { /* fork a child process */ fork(); ...
0
votes
1answer
41 views

Emacs windows, frames, server and clients: threads or processes?

From http://www.gnu.org/software/emacs/tour/ Emacs server Some people like to keep only a single instance of Emacs open and edit all their files in there. Doing this has a few advantages: ...
70
votes
6answers
39k views

How can I close a terminal without killing the command running in it?

Sometimes I want to start a process and forget about it. If I start it from the command line, like this: redshift I can't close the terminal, or it will kill the process. Can I run a command in ...
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2answers
38 views

Remove unneeded file lock in script

I have some script using flock executable. It works well. Problem is when this script calls another script, and it creates background process. In this situation background process inherits file locked ...
2
votes
1answer
7k views

How to find Heap memory of a running process? [duplicate]

I would like to know how to find the heap memory of a process that is running in the background. Is there any command that allows such?
1
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1answer
255 views

List of killed processes HP-UX

Is there a file similar to the one in this answer http://unix.stackexchange.com/a/10078/5027 to determine the processes which were killed, in a certain time, for example, yesterday, in HP-UX?
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2answers
40 views

Call background process back to stdout

Is it possible to "call" a background process output to be shown in the terminal? Example: cron starts apt-get to update the system and I want to see the output of apt-get
2
votes
1answer
49 views

I can't install new packages and can't update and upgrade

I'm trying to install some program on Ubuntu, but when I try it I got the following error.- E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock ...
0
votes
1answer
19 views

How to add a progress bar to cryptsetup luksFormat?

Example command. cryptsetup --hash sha512 -c aes-xts-plain64 --key-size 512 luksFormat /dev/loop0 This can take quite a while for big files / on slow disks. How to add a progress bar?
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votes
1answer
24 views

What do brackets mean in the output of pstree?

What are the differences between [] and {} and [{}] used to enclose a process in the output of pstree? I guess [] is used for specifying more than one processes. For example, ...
0
votes
0answers
22 views

How do you adjust other user's job priority?

Let's say your coworker started a very intense process and went home. It's occupying most of the CPU resources, and you can't do your stuffs because of it. If it was your own process, you could run ...
0
votes
1answer
18 views

/usr/bin/X :0 -audit process

Hello I am trying to solve some internet problems that I have. It is a university computer and I do not have root access. I want to understand what is this processor, that root has started, and if you ...
4
votes
0answers
65 views

How do I execute in background / return early?

For reference, I'm using phpseclib to control a remote SSH server using the 'root' account. I have to start/stop a java process which is ran in the background. Stopping works fine with killall java ...
1
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2answers
3k views

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% | ...
5
votes
2answers
240 views

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. ...
1
vote
1answer
57 views

How to kill - softly? [duplicate]

If I want to kill a process as careful and politely as possible, which signals should I use in a kill command, in which order? I would like to give the programm any kind of time to clean up, if it ...
2
votes
1answer
570 views

What is the difference in CPU utilization between 'ps aux' and 'ps -ef'?

I use Ubuntu 12.04.1 Linux. I see a difference between %CPU and C output format of ps command for a process. It is not clearly noted in the ps man page. Man pages says: CODE HEADER ...
3
votes
1answer
59 views

Process history in Unix/Linux systems

I know that ps -efl shows running processes on *nix systems. I would like to check history of the (past) processes that have been run on a particular machine, preferably with all the information ps ...
70
votes
2answers
5k views

How does Linux “kill” a process?

It often baffles me that, although I have been working professionally with computers for several decades and Linux for a decade, I actually treat most of the OS' functionality as a black box, not ...
0
votes
1answer
28 views

Loginuid, should be allowed to change or not (mutable or not)?

I am trying to configure the linux kernel. I was confused by Make audit loginuid immutable (AUDIT_LOGINUID_IMMUTABLE) [N/y/?]. The help says: +config AUDIT_LOGINUID_IMMUTABLE + bool "Make ...
3
votes
1answer
42 views

Different between `ulimit -e` and `renice`?

I would like to run a backup script in low CPU and disk I/O. Is there any different between this: #!/bin/bash ulimit -e 19 ionice -c3 -p $$ and this: #!/bin/bash ionice -c3 -p $$ renice -n 19 ...
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vote
4answers
6k views

Kill all process of users in Ubuntu?

How to kill all process of one user? When I make ps aux I obtain a list of process with several users, and I want to kill all process of user name1 for example! What's a command to do that in Ubuntu? ...
5
votes
2answers
49 views

How can I see i/o stats for a briefly running process?

For long running processes like init, I can do things like $ cat /proc/[pid]/io What can I do if I want to see stats for a briefly running process such as a command line utility like ls? I don't ...