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

learn more… | top users | synonyms (1)

1
vote
1answer
44 views

Is there a way to check which process terminates first during reboot

Assuming I have 2 processes running. Is there any way for me to check which process terminates first during reboot/shutdown? From this link, it tells about appending boot to a file. Yet, I still don't ...
1
vote
1answer
156 views

Track down process that has notty

I have a Linux server (Red Hat 2.6 kernel) which had a spike in load due to an Rsync process which seems to have forked many times, but the process was run by rsyncuser@notty I didnt see any cron job ...
2
votes
2answers
342 views

How can a normal user trigger a root cron task to execute immediately, without delay?

I have a root cron task that runs every day. But I want to allow normal users to request that it run immediately, if they so wish. It is a harmless process and it can run as often as needed and these ...
1
vote
1answer
104 views

spawning multiple Background processes

I have a file which has 2,000,000 lines in it. I am running some commands for each line. I was trying to achieve some parallelism using GNU-parallel and swift as discussed here. However, I got an ...
1
vote
1answer
118 views

Gnu Parallel: more than one per CPU? [closed]

If I only have two cores, does parallel only run two processes at a time? I guess I'm still confused about processes, threads, and cores....
0
votes
1answer
78 views

How can I rejoin a process running

I am very new to using Linux. I have a 'machine' on Amazon and I was trying to learn how to use Python on this machine. I started running Python—had to step away for a few minutes and the connection ...
0
votes
1answer
117 views

Full path name of bash? and base process of Linux?

I am new to Linux and I recently had a test at school which had the following questions: What is the full path name of bash? What is the base process of Linux? I couldn't answer these. Does anyone ...
1
vote
3answers
882 views

A command which returns either a process ID, if running, or some other output if not?

I'm looking for a command that will give me the PID, and it's not running it should give me some output other than blank. In my program, sometimes the library I'm using gives blank output even if ...
2
votes
1answer
124 views

How to move process from one namespace to other?

This question is similar to my question about how to list namespaces. So in addtition, I'd like to know some information about moving processes from one namespace to other? E.g. I have processes of ...
1
vote
1answer
54 views

How do I identify the user that is attempting to create a file?

I have a PHP script that is attempting to create a file, but it can not because of permissions. I would like to identify which user the system sees as the one requesting to create the file. I would ...
8
votes
1answer
338 views

how to find out namespace of a particular process?

I already asked a question about how to list all namespaces in Linux, but there wasn't any correct and exact answers, so I want to find out a method which can help me to find out the namespace of PID ...
2
votes
1answer
96 views

How to renice a group of processes?

lb build can build live system image, and it invokes many processes while building the image. If I start it as below: # nice -n 19 ionice -n 7 -c 3 lb build all the children processes get the same ...
2
votes
1answer
54 views

tftpd runs as root, despite explicit option “--user tftp”

I start my tftp server with the option --user tftp so that it runs as user tftp instead of root. However, ps shows that the process still runs as root ps aux| grep tftp root 2542 0.0 0.0 ...
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
2answers
547 views

How do I run two ongoing processes at once in linux/bash?

I would like to know how I can run two ongoing processes at the same time in Linux/bash. basically, I have a Node web server, and a MJPG-Streamer server. I want to run both these processes at once, ...
1
vote
3answers
3k views

How to get the Job ID? [duplicate]

As we know, the shell enables the user to run background processes using & at the command line's end. Each background process is identified by a job ID and, of course, by it's PID. When I'm ...
5
votes
2answers
185 views

Why do forked processes sometimes appear with brackets [] around their name in ps? [duplicate]

On a Linux system a C process is started on boot, which creates a fork of itself. It is not a kernal process or something. In most cases a ps -ef show both processes as expecxted, but sometimes it ...
1
vote
2answers
62 views

Increase nice value for many processes

Say I have launched a couple of non-timecritical applications such as a text editor a web browser etc and one more time critical (audio)application. Is there a utility that simulates the opposite of ...
5
votes
2answers
274 views

Processes do not respond to my signals

I have a strange behavior on my system. When I invoke a command in the shell (bash version 4.2.45(1)-release), say top or cat, the running program (the process) does not respond to Ctrl+C. I even ...
9
votes
1answer
181 views

Why do I need dbus?

I recently removed dbus from my system (along with consolekit and polkit). I didn't notice any change (I was running it as system daemon and per-user from .xinitrc). However, many people claim that ...
8
votes
3answers
261 views

If you ^Z from a process, it gets “stopped”. How do you switch back in?

I accidentally "stopped" my telnet process. Now I can neither "switch back" into it, nor can I kill it (it won't respond to kill 92929, where 92929 is the processid.) So, my question is, if you have ...
1
vote
1answer
152 views

fg a bg process because you forgot to redirect output to /dev/null

I did Ctrl+Z bg with the intention of disowning next, but I forgot to redirect, now I cant get to my terminal because the scrolling of the output (tarballed a huge directory with verbose set). How do ...
34
votes
6answers
4k views

Does pressing ctrl-c several times make the running program close more quickly?

I often start to read a huge file and then want to quit after a while, but there is a lag from pressing Ctrl+C to the program stops. Is there a chance of shortening the lag by pressing the Ctrl+C key ...
0
votes
1answer
464 views

root permission denied on /proc/1/exe

I just performed a fresh ubuntu install and i am seeing the following in lsof: userA@az1:~$ lsof COMMAND PID TID USER FD TYPE DEVICE SIZE/OFF NODE NAME init 1 ...
1
vote
2answers
332 views

How to terminate a background process in Linux when the pid is unknown?

I have a job dispatcher bash shell script containing below codes: for (( i=0; i<$toBeDoneNum; i=i+1 )) do while true do processNum=`ps aux | grep Checking | wc -l` ...
1
vote
1answer
216 views

moving from user mode to kernel mode

I read the following: "All processes begin execution in user mode, and they switch to kernel mode only when obtaining a service provided by the kernel." When it says "obtaining a service ...
2
votes
1answer
918 views

How to check the status of bash shell script while executing from Python script?

I have a simple Python script which will execute a shell script using subprocess module in Python. Below is my Python shell script which is calling testing.sh shell script and it works fine. import ...
1
vote
3answers
227 views

Detect process if not found then run it

I am running several process at startup using "crontab -e" @reboot tranmission-daemon && python defualt.py && python MonitorService.py But for some reason, those service can ...
2
votes
2answers
1k views

Finding the PID of the process using a specific port?

I am installing hadoop on my Ubuntu system. When I start it, it reports that port 9000 is busy. I used netstat -nlp|grep 9000 to see if such a port exists and I got this: tcp 0 0 ...
3
votes
1answer
195 views

How does the piping in this command ultimately achieve to kill the process?

I have seen the following line in a bash script for killing a process(in this case started with the command loadgen): ps xww | grep -i "loadgen" | grep "PATTERNMATCH_FACT.xml" | cut -c1-5 | xargs -i ...
2
votes
2answers
47 views

Processes lose attachment to shell when started via bash -x

Normally, if I run emacs & and then close the shell, emacs will exit. However, if I run bash -x foo.foo (where foo.foo is a script that runs emacs &), then emacs will remain open even when I ...
0
votes
1answer
240 views

How to get pid of su --session-command file thats ran on there [closed]

This line ran in a script su --session-command="$javaCommandLine & >>$serviceLogFile 2>&1 & echo \$! >$pidFile" $serviceUser || return 1 pid="$(<$pidFile)" echo $pid The ...
6
votes
2answers
452 views

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 ...
4
votes
3answers
297 views

Locate a directory from a relative path in ps output

When I executed the command to give the pid of my processes running, it gave me like this - user@machineA:/$ ps -eo pid,command | grep exhibitor | grep java | grep -v grep 1615 java -jar ...
5
votes
1answer
998 views

The meaning of output of pmap

I wrote main.c in Linux: int main() { while (1){} } When I compile and start it, I can pmap it: # pmap 28578 28578: ./a.out 0000000000400000 4K r-x-- /root/a.out 0000000000600000 4K ...
8
votes
2answers
280 views

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 ...
2
votes
4answers
145 views

ssh ncat keeps ncat process running after disconnect; how do I prevent that?

If I run the command $ ssh othermachine ncat localhost 10000 that opens an ssh session to "othermachine" and pipes it into an ncat process. (There's something else listening on "othermachine" port ...
14
votes
3answers
11k views

How to stop a background process?

I have started a wget on remote machine in background using &. Suddenly it stops downloading. I want to stop its process, then start it again. How can I stop it? I haven't close its shell window. ...
9
votes
1answer
240 views

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 ...
2
votes
2answers
142 views

Why do I see more processes in KVM than in OpenVZ?

I've got a 512mb Centos 6 VPS running on KVM. Now another VPS from a org. I manage is running on OVZ. When I type top on the KVM one, I get a whole list of all sort off processes. But when I do this ...
0
votes
3answers
167 views

Owner of init and xterm

I don't understand what is owner of process. Owner of bash is me. Then who is owner of init and xterm? I searched on google but I can't find.
0
votes
3answers
1k views

Cannot kill teamviewer process

My main desktop has Mint 14 and I approached it via SSH from another computer, because I didn't have a screen on the Mint one. Then I tried to start teamviewer just I order to launch its desktop ...
1
vote
2answers
142 views

How do I draw a process tree from my shell to the kernel?

I can't understand this problem For each process in the tree, indicate the name of the process, the process's ID number, and the name of the owner of the process.
10
votes
3answers
292 views

How do I wait on a program started in another shell

I have a program that does a large a amount of work (takes about 4-5 hours) that gets started by cron when all the data it works with becomes available. Sometimes, when I am waiting for it to finish, ...
2
votes
0answers
355 views

How to get start time for a defunct process on AIX?

When I run the following commands on AIX: 22:root@SERVER:/root # ps -ef | head -1 UID PID PPID C STIME TTY TIME CMD 22:root@SERVER:/root # ps -ef | grep defunct | head -1 ...
5
votes
2answers
443 views

Obtaining PID of command earlier in Pipeline

I'm writing a bash script to use inotifywait to monitor a directory and kick off actions when changes are detected. Something like: inotifywait -m ... | while read f; do something; done Since ...
1
vote
1answer
75 views

Limiting processes by memory under Linux

We must launch several hungry processes on a Linux system. These processes often need several Go (~5Go) of memory to run (total memory: 16Go RAM + 2Go swap). At first, when the system was running ...
6
votes
2answers
148 views

Why are there so few “running” processes?

On all of BSD/Linux/MacOS and Solaris, I made an observation - no matter how busy the system is, top always reports very few (usually 1-2) running processes. According to my limited understanding, a ...
3
votes
3answers
725 views

Why do top and ps show different PIDs for the same processes?

When I run top -H, I see that my multiple mysql threads all have the same PID. However, in ps -eLf I see each one has a different PID: ps -eLf UID PID PPID LWP C NLWP STIME TTY ...
5
votes
2answers
316 views

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 ...