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

learn more… | top users | synonyms (1)

1
vote
2answers
60 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
247 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
176 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
233 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
138 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
424 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
287 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
200 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
801 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
222 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 ...
1
vote
2answers
979 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
183 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
46 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
208 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
397 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
262 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
879 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
274 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
140 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 ...
13
votes
3answers
9k 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
235 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
133 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
149 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
132 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
269 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
298 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
401 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
74 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
146 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
590 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
292 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 ...
2
votes
1answer
132 views

Which system calls could create a new process?

When executing ps command in my Linux system i see some user processes twice (different PID...). I wonder if they are new processes or threads of the same process. I know some functions in standard C ...
5
votes
3answers
352 views

Using `kill -s 0 $pid` vs `[[ -e /proc/$pid ]]` to detect if PID is running

One of the idioms often used to check if process is running is to use kill -s 0 $pid. My question is, does it have any upsides over using [[ -e /proc/$pid ]] construct? The script I'm writing is ...
5
votes
2answers
500 views

Get the PID of file creation

I am writing a bash script that creates 5 files with the extension ".P" and write a line of "something" into them. "P" represents a number and it's the PID of the process that creates the file. How ...
2
votes
1answer
261 views

Difference between process in background and daemon [duplicate]

What is technically the difference of a process that started in foreground and was manually put into background and a daemon? Do they have different properties?
3
votes
1answer
73 views

What is the rtsbpp-polling process doing?

In Ubuntu 12.04 LTS when I run the top command I see a process called rtsbpp-polling. Googling it gives only just a few hits to the Gentoo Linux forum that does not seem to be relevant (they don't ...
21
votes
3answers
955 views

If computers start counting at 0, why does the init process have a pid of 1?

Not much to put here in the body, the question is self explanatory.
1
vote
0answers
73 views

How to send a running process to jail?

"Go directly to jail; do not pass go, do not collect $200" — Monopoly Is there any way to make a running process's all future file access behave as if it has always been in a chroot environment?
1
vote
1answer
162 views

Grep Wvdial output while it is running

I want to grep the output from wvdial while wvdial is running. Actually I want to fire a task when the modem is connected. I want to do this in the following way: grep string "IP address", if it is ...
1
vote
2answers
57 views

What information about a process is retrievable after it is terminated? [duplicate]

After a process has been terminated, is it possible to retrieve any information about it, such as when it started and finished, &c. Is it possible to enable logging of this information?
69
votes
4answers
1k views

Can I somehow add a “&& prog2” to an already running prog1?

Most shells provide functions like && and ; to chain the execution of commands in certain ways. But what if a command is already running, can I still somehow add another command to be executed ...
1
vote
2answers
156 views

Is it possible to control xterm (or specifically a process that xterm has started) from another process?

If I start a process with xterm like this (where omxplayer is the process xterm is starting): xterm -fullscreen -fg black -bg black -e omxplayer -o hdmi -r %f Is it possible for me to write to ...
2
votes
2answers
272 views

AIX open() : file descriptor is zero (!?)

A daemon process, on detecting the presence of a text file in a particular directory then launches an executable file which opens the aforementioned text file in order to read and then transmit its ...
1
vote
1answer
153 views

How do I print the process name next to the process ID number in a file?

I'm redirecting results for something into a file and I also need to find the process name and ID number and redirect it to the file as well. I'm guessing the process name is the command in which I'm ...
1
vote
1answer
1k views

Modify 'Soft Limit' of 'Max processes'

I tried ulimit -u 2000 and ulimit -Su 2000 to modify the 'Max processes', and started up my program, but failed. I found file '/proc/pid/limit' is still: Max processes 1024 ...
2
votes
1answer
206 views

accessing stdin/stdout of a process started in another tty

I logged in to my linux physically(say tty1) and started a process that watches stdin for commands and has some stdout-put. How can I access/use this process from a SSH session?
4
votes
2answers
1k views

How to identify a process which has no pid?

I have a process which listen to 2 ports : 45136/tcp and 37208/udp (actually I assume it is the same process). But netstat doesn't return any pid : netstat -antlp | grep 45136 tcp 0 0 ...
2
votes
2answers
78 views

Detecting Kernal Thread on Older Kernel Version

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 ...