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

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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",$1,"sleep 10" && pid=$!}' ...
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4answers
6k views

Why is SIGINT not propagated to childs process when sent to it's parent process?

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: ...
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1answer
1k 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 ...
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4answers
625 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?
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1answer
585 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 ...
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2answers
52 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 ...
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1answer
821 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. ...
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114 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 ...
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1answer
122 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: ...
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2answers
166 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
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1answer
6k 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 ...
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1answer
53 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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1answer
215 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, ...
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0answers
24 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 ...
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0answers
176 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 ...
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1answer
97 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 ...
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2answers
336 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. ...
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1answer
168 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 ...
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1answer
1k 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 ...
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1answer
102 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 ...
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1answer
120 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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2answers
110 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 ...
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2answers
363 views

Using /proc/stat for the number of processes running on the system

How does one find out the true number of processes that is running on your system. A number of articles mention using ps in order to count the number of processes. But recently I looked at cat ...
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0answers
46 views

Why are the process priorities not respected?

I was running four jobs in the background with HTCondor. It sets the priority to 10. Then I was compiling something with make -j4 in the foreground (priority 0). However, the HTCondor jobs still got ...
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1answer
60 views

The current path of a process

Suppose I write a program, which outputs a file under a relative path (as opposed to a full/absolute path) - let's say, the current path. Then I compile it and store the executable under some dir ...
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1answer
1k views

Maximum memory usable by a 32 bit RHEL 6 system

I have installed a 32 bit RHEL OS on a 64 bit system. From the wiki page of PAE: The Linux kernel includes full PAE mode support starting with version 2.3.23, with Linus Torvalds mentioning ...
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1answer
118 views

Process's father after setpgid(0,0);

I have a process P1 (child of some parent process P0) both in the same process group. P1 somewhere in his code runs: setpgid(0,0); then a new process group is created (where the group leader is P1). ...
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4answers
2k views

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 following: #include <unistd.h> int main(){ chdir("/home/enedil/projects/algo"); return 0; } I ...
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1answer
2k views

What is meant by “Unknown instance” when restarting a service?

I am trying to get vsftpd file server running on Ubuntu 13.10, I'm unable to connect to the server from another network, although this other network is connected to the server's network and ping is ...
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1answer
54 views

How can I tell why a process is waiting?

I'm trying to run a command on OSX Mavericks and it seems to be hanging. I found out that Control + T is a Unix command to show the status of a foreground job. Pressing it several times over the ...
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1answer
2k views

Kill any service running at a specific port

I am trying to write a script that kills service running at a specific port. This is my script: a=$(ps ax | grep 4990 | grep java | awk '{print $1}') kill -9 $a It's a java program. This script ...
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2answers
983 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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69 views

How can i get the process with the biggest pid?

How can I get the process with the biggest pid using ps?
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1answer
2k views

long format of ps command in Solaris

Jobs with a long command-line is not printing in Solaris: bash-3.2$ /usr/ucb/ps auxwww | grep ftf | awk '{print $NF}' | head -5 /proj/cmp01/app/btws/cfg/btw /proj/cmp01/app/btws/cfg/btw ...
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0answers
71 views

Cgroups - memory subsystem

I want to set the memory.limit_in_bytes parameter for a control group and disable OOM, so processes freeze when the limit is reached. But i want to change that limit dynamically, if there is more ...
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2answers
314 views

Do all Linux processes write EOF to stdout when they are terminating/have finished terminating?

I'm having trouble with sending shutdown -h 0 to a lxc Debian container (i.e. executing this command in the lxc) with with the python pexpect module (in a python script). In this module the user can ...
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1answer
125 views

How to determine who started a process? [duplicate]

every few minutes I found this process running root 949062 100 0.0 37204 1488 ? R< 05:14 0:51 /usr/local/cpanel/3rdparty/bin/clamdscan --quiet --no-summary /etc/passwd It's ...
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1answer
1k views

Why is the PGID of my child processes not the PID of the parent?

So I keep reading everywhere that this command should terminate all child processes of the parent process: kill -- -$$ Using a negative ID with the kill command references a PGID and from the ...
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1answer
233 views

Launch background processes in one group and later kill them all

The other day I tried writing a script that would kill a PID and all its children processes, but after spending some time on it, I decided it wasn't trustworthy, because sometimes some of the children ...
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1answer
451 views

Monitoring filesystem activity

Say, I have a program, and I want to monitor its filesystem activity (what files/directories are created/modified/deleted etc.) This program may be capable of spawning further processes, and thus, I ...
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1answer
31 views

killall <processname> throughout the system [closed]

I'm opening two terminal windows. Terminal 1 - I run process1 Terminal 2 - I run process2 I then terminate both process using Ctrl+Z in each window. I type killall -9 process1 in Terminal 2 , ...
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2answers
156 views

CPU percentage of a single process

How do I get the average CPU percentage (for every second) consumed by a single process since it starts until it ends (exists)? Could I make this with Top?
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4answers
224 views

Single instance of script, but only with same arguments

I have this beautiful little code here that will exit from a script if there's another instance of it running: single_instance(){ if pidof -x "${0##*/}" -o %PPID >/dev/null; then exit ...
5
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1answer
118 views

Why does `bash -c somecommand` sometimes not leave a bash process?

On an Ubuntu 12.04, with GNU bash, version 4.2.25(1)-release (x86_64-pc-linux-gnu), I tried the following command: $ bash -c 'pstree -s $$' init───sshd───sshd───sshd───bash───pstree $ bash -c 'pstree ...
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3answers
877 views

detect process eating cpu without: top, htop, ps?

I went thru a problem where I could only guess what process was eating the cpu. My cpu usage was about 80% for all cores at psensor. I tried htop, top and ps -A -o pcpu,pid,cmd --sort +pcpu (the ...
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0answers
76 views

CGroup Processes Not Terminated even when main process has been killed through Systemctl stop command

I am running systemctl stop process command for some process. Please find the output for systemctl status process below: Loaded: loaded Active: deactivating (stop-sigterm) CGroup: ...
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2answers
29 views

Meaning of PF_VCPU and PF_WQ_WORKER

do you know what the constants meaning is defined in linux/sched.h: #define PF_VCPU 0x00000010 /* I'm a virtual CPU */ #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ What ...
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1answer
15 views

how to suspend other nonrelated processes to allow a proces in interest to occupy the CPU?

Is it possible to first find out what processes are necessary to run a process in interest, and then suspend all other unrelated processes to allow the process in interest to use the CPU as much ...
0
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2answers
986 views

How to compute Linux slab memory leak in GNU/Linux ( proc/slabinfo ) of running process

How to compute Linux slab memory leak in GNU/Linux ( proc/slabinfo ) of running process ? I'm want to free usage is not working properly . I want to way how to check Memory Usage & Memory Leak ...
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1answer
76 views

How are zombie processes handled when the parent dies?

Which technique does the Unix system use to remove zombie processes whose parent has terminated?