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

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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 ...
4
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3answers
3k views

Slow down just one process to regulate CPU temperature

I have a program. When it is running, the CPU temperature raise from 50 to 80 Celcius, which is my major concern. I can control the CPU frequency to slow it down, but other processes will be slowed ...
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2answers
1k views

Find the PID's of all threads of a process without ps or pidof

So the system I'm working on (BusyBox) has a ps that takes no command line arguments and pidof returns nothing even though it exists within /sbin and points to killall5. Another issue I had is that ...
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0answers
92 views

how to find out why process is taking more cpu usage

Sometimes load goes high on server for java processes. Multiple java processes are running and consuming high load on server. I want to know how to check that why process is taking too much load.
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2answers
316 views

Monitoring process activities using system calls only (without utilities like `top`)

I want to obtain information about memory used by different users and different processes which users are running and statistics about those processes like memory consumption, execution speed, etc., ...
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6answers
5k views

What is using this network socket?

I'm trying to use NTP to update the time on my machine. However, it gives me an error: host # ntpdate ntp1.example.org 10 Aug 12:38:50 ntpdate[7696]: the NTP socket is in use, exiting What does the ...
2
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1answer
149 views

Using ps and watch to observe parent and child process

I got a parent and a child process running, I know their IDs. How do I utilize 'ps' and 'watch' to filter them out, so that I can see their used CPU times? I tried 'watch ps -u USERNAME', but as you ...
22
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6answers
66k views

Is there a way to see details of all the threads that a process has in Linux?

For Windows, I think Process Explorer shows you all the threads under a process. Is there a similar command line utility for Linux that can show me details about all the threads a particular process ...
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5answers
591 views

Getting the pid's of a program line by line

I can find the pid's of my program instances by issuing command like this: pidof avconv Which is giving me results 16616 16283 16279 16198 16175 16035 15073 14049 4922 But how can I output the ...
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1answer
176 views

Orphan process's parent id is not 1 when parent process executed from GNOME Terminal

I start a new process from GNOME Terminal and then this process fork a child. But when I killed the parent process the orphaned process's parent id became something other than 1 which represent init ...
2
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1answer
130 views

how to get the full command line args passed to a process on unix/linux systems? [duplicate]

I am looking for a reliable way to get the full command line args passed to a process even when these are very long. I do know about ps -f -p <pid> and /proc/<pid>/cmdline, both of which ...
5
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2answers
741 views

How can a background process know its own PID?

I'm using bash on a RH Linux system. Normally, you can get your own PID with the variable $$. However, if a script runs one of its own functions as a background process - that doesn't work; all ...
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1answer
56 views

Set ionice for a multi-threaded application

I have a program that spawns multiple threads, all of which do fairly intensive IO, running on the background. I want to set the scheduling class to idle so that it doesn't clog up the system; ...
3
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1answer
235 views

Change the parent process of a process?

Is it possible to change the parent process of a process? If yes, how? For example, how does screen manage to attach a screen session and the processes running inside it to different shell ...
8
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4answers
9k views

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 ...
0
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0answers
20 views

What does disown do? [duplicate]

$ help disown disown: disown [-h] [-ar] [jobspec ...] Remove jobs from current shell. Does disown on a process change the parent process of the process? I.e. make the parent shell process ...
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0answers
23 views

How do processes, jobs and session relate to each other ? [duplicate]

Could you deliver an answer in a way that does not require too much special knowledge in advance, yet also deliver some deeper insight to a lesser advanced Linux User ?
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2answers
29 views

Can someone explain exactly what is happening with single quotes and double quotes with process IDs in the below example? [duplicate]

[root@localhost ~]# echo $$ 16991 [root@localhost ~]# bash -c "echo $$" 16991 [root@localhost ~]# bash -c "echo $$" 16991 [root@localhost ~]# bash -c 'echo $$' 21062 [root@localhost ~]# bash -c 'echo ...
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2answers
54 views

List running processes without procfs

I'd like to list running process (like using ps or top), but there is no procfs mounted. The procfs not being mounted is intentional, and is made to prevent malicious user to access systems ...
5
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3answers
576 views

Dynamic file content generation: Satisfying a 'file open' by a 'process execution'

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 ...
1
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0answers
109 views

How can I find which process is eating my memory? [duplicate]

My Linux system sometimes reaches 90% memory usage. We are running some Java processes, and top shows overall usage as 45%. If I stop the running processes, usage reduces to 5-10%. I want to list ...
2
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1answer
43 views

Re-enter PID 1 namespace

I'm trying to enter PID namespace that process with PID 1 is in from a process cloned with CLONE_NEWPID. I keep getting Invalid argument error. In other words, I clone a child process with clone() ...
27
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9answers
3k views

How can I kill a process and be sure the PID hasn't been reused

Suppose, for example, you have a shell script similar to: longrunningthing & p=$! echo Killing longrunningthing on PID $p in 24 hours sleep 86400 echo Time up! kill $p Should do the trick, ...
3
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1answer
47 views

Solaris 10 system - used disc space keeps on increasing even after deleting the directory

I deleted a directory on slice mmf but it came back - the size is still same and also it keeps increasing. The reason for deleting the directory is that I couldn't find the process linked to creating ...
2
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1answer
32 views

Is there a way to suspend an process belongs to shell A and foreground it in shell B?

I knew how to suspend one process and bring it into foreground in current shell, but I have no idea about that If I have run a process in shell A and now I want to bring it into foreground in current ...
31
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5answers
10k views

Measuring RAM usage of a program

time is a brilliant command if you want to figure out how much CPU time a given command takes. I am looking for something similar that can measure the max RAM usage of the program and any children. ...
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1answer
376 views

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 ...
2
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3answers
290 views

How can I determine if a process is a system process?

I'm reading the /proc directory (or pseudo-fs) to find all processes. I'm getting the information I need from /proc/[pid]/status but there's something else I need. Is there any way to figure out which ...
22
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5answers
9k 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 ...
13
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3answers
29k views

How to list processes locking file?

Using flock, several processes can have a shared lock at the same time, or be waiting to acquire a write lock. How do I get a list of these processes? That is, for a given file X, ideally to find the ...
13
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2answers
5k 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) ...
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2answers
73 views

Should I use Linux's acct (BSD process accounting) to track a process behavior?

I have a daemon process (slapd) which sometimes stops with no apparent reason. No segfault occurs. Nothing special in the logs. So, I'm trying to use acct to track the process' life, especially its ...
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3answers
2k views

Process descendants

I'm trying to build a process container. The container will trigger other programs. For example - a bash script that launches running background tasks with '&' usage. The important feature I'm ...
5
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3answers
11k views

Bash script wait for processes and get return code

I am trying to create a script which will start many background command. For each background command I need to get the return code. I have been trying the following script : #!/bin/bash set -x ...
0
votes
1answer
47 views

writing a script & trying to kill a process

So I am very new to Unix, I understand this question may be very simple My goal is to write a script that will show all the running processes and ask the user if they want to kill each process... For ...
3
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5answers
130 views

Get PID of process started by time

Say I run time ./a.out, then I can get the PID of time by the variable $!. But how do I get the PID of a.out? Of course, I could parse the output of ps, but I want a more elegant solution. I've ...
6
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3answers
433 views

Which of the following codes will run in the same process of the current shell

A. { echo "Hello World"; } >outputfile B. ( echo "Hello World" ) >outputfile C. ./anothershell.sh D. /bin/echo "Hello World" Which is right? And what kind of command can run in the same ...
5
votes
4answers
452 views

list graphical processes from terminal

Do no confuse the question here with how to list processes graphically, that is not what I am asking. In the Terminal, how can i see which processes have a GUI? as in things like firefox, vlc, ...
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2answers
229 views

How to close a window of a crashed application?

Im using Awesome as desktop environment, as you can see in the image below, the application (aMule) crashed but the window is still open, so I would like to close it to restart it, but as you can see ...
0
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1answer
206 views

/usr/bin/awk: Argument list too long

I am trying to run the following bash script: #!/bin/bash file=$1 filename=${file%%.*} line1=$(sed -n 1~2p ${file}) seqs=$(grep -v '^>' ${file}) pos=$(echo "${line1}" | awk -F"[__]" ...
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0answers
23 views

Perform task on waking up from suspend

I have program that misbehaves when my pc wakes up from suspend to ram, it starts using up to 40% of processor time so i usually have to kill it manually. How can i set specific command (pkill in ...
2
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1answer
126 views

monitor multiple pids with top

I want to monitor memory usage for several processes and came up with a command like this: ps aux |grep -e postgres -e unicorn -e nginx|cut -d' ' -f2|for i in $(xargs); do echo $i; done 16112 16113 ...
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2answers
40 views

How to open process again? [duplicate]

From my home pc using putty, I ssh'ed into a remote server, and I ran a python program that takes hours to complete, and as it runs it prints stuff. Now after a while, my internet disconnected, and I ...
2
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3answers
121 views

Can you make a process pool with shell scripts?

Say I have a great number of jobs (dozens or hundreds) that need doing, but they're CPU intensive and only a few can be run at once. Is there an easy way to run X jobs at once and start a new one ...
0
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2answers
163 views

Meaning of the pstree output

-bash-3.2$ pstree 27108 Script.sh---java---15*[{java}] What does this 15* mean here, also any meanings defined for [] & {} in the context of command?
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1answer
59 views

How to find process which flood the whole network

I have a laptop with Fedora 21 and TP-Link router with DD-WRT software. Sometimes my whole internet stops for any device. When I reboot my laptop or just I turn off wireless, the internet works fine. ...
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1answer
159 views

shell script to auto kill processes matching certain criteria

when running top it shows a couple of processes got nearly 100% cpu usage of the command 'perl' PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 21287 simon 15 0 4141 ...
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0answers
58 views

process blocked in msgrcv

I have a process that is blocked in msgrcv as shown by ps -eo pid,tid,wchan. Is there any way to find the PID of the process that my process is expecting to receive a message from? The communication ...
0
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1answer
178 views

how to get list of all processes accessing a shared library [duplicate]

I know that ldd utility can list all libraries linked to a process but I want it the other way around. I want all processes linked to a library. I want to replace a shared library without crashing the ...
4
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3answers
134 views

How to not show the stdout output of a running process?

When a running process gives lots of stdout output throughout its lengthy running process, you don't want to kill it and rerun it. How can you not show the output? Thanks.