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

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2
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232 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 ...
21
votes
5answers
8k 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 ...
12
votes
3answers
26k 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 ...
12
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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) ...
1
vote
2answers
56 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 ...
8
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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
votes
3answers
10k 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
42 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
votes
5answers
121 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
votes
3answers
428 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
425 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, ...
3
votes
2answers
225 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
votes
1answer
187 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"[__]" ...
0
votes
0answers
22 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
votes
1answer
105 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 ...
0
votes
2answers
37 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
votes
3answers
104 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
115 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?
1
vote
1answer
49 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. ...
1
vote
1answer
122 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 ...
1
vote
0answers
57 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
votes
1answer
116 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
votes
3answers
125 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.
3
votes
1answer
73 views

Minus and Plus Sign in jobs Process

These commands are running in the background: foo@contoso ~ $ sleep 30 & foo@contoso ~ $ sleep 60 & foo@contoso ~ $ sleep 90 & What is the minus and plus sign after running jobs process? ...
3
votes
4answers
7k views

monitoring file changes + process access to files

I would like to see what's happening in my app server folders, which files are changed by process x or which *.war files has been changed (replaced/created) in last x minutes. I am software developer ...
2
votes
1answer
46 views

What's the easiest way to detect what signals are being sent to a process?

I'm trying to debug an issue with my shell (specifically, fish) sending signals to my background processes. I'd like to be able to recognize what signals a process is receiving. Ideally, I'd like ...
0
votes
2answers
89 views

Why can't I kill the shell using the PID obtained from the $$ special variable? [duplicate]

After I have learned that the $$ special variable holds the process number of the shell, I tried too kill the shell by simply: kill , however this did not work, I also tried some variations, but them ...
0
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0answers
64 views

Send a remote job to a remote server (second machine) and end the first process

I Installed ScanBD for my scanner on a RaspberryPi. I also wrote a script to process the files once the scanning function has completed. SCANBD Script SCANBD Process Script Currently, the scans are ...
2
votes
1answer
54 views

Creating symlinks in the etc directory without root access

What I would like to create if I had root access would be a symlink from some file or folder in the /etc to another file or folder in the /etc. However, I do not have root access. Is there any way to ...
2
votes
3answers
90 views

Controlling the environ passed to child process by bash

I am using x86_64 GNU/Linux with bash #include <stdio.h> #include <stdlib.h> int main(int argc, char **argv) { system("set > setc"); // A subset of `$ ...
0
votes
1answer
85 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 ...
1
vote
3answers
71 views

Can a suspended process be copied?

If I suspend a running job in bash using ctrl-z is there a way to copy it. So that I now have two processes that are the same. I am running a python script that loads several files and does some ...
6
votes
9answers
18k 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 ...
107
votes
7answers
75k 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 ...
28
votes
6answers
51k views

Determining what process is bound to a port

I know that using the command: lsof -i TCP (or some variant of parameters with lsof) I can determine which process is bound to a particular port. This is useful say if I'm trying to start ...
80
votes
4answers
2k 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 ...
3
votes
1answer
45 views

Parent restarted by child doesn't respond to CTRL-C

I wrote a program. It starts a process (call it A) that spawns a child process (call it D) that shutdowns and restarts A. Problem is, now I can't kill A nicely from the terminal (ie. CTRL-C isn't ...
2
votes
1answer
223 views

Why can't I kill this process?

Problem I would like to kill a process called raspivid (program which records videos using a Raspberry Pi Camera) but I cannot... This is how I call it: #!/bin/bash #Start recording... raspivid -w ...
37
votes
5answers
79k views

How can I get a full process list in solaris, without truncated lines?

Is there a way to generate a full process listing in solaris, without truncated lines? I've tried the ps command, with the following arguments: -f Generates a full listing. ...
0
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0answers
15 views

How to run ping in background, disconnect from current terminal session and get back the ping process later on from new terminal session? [duplicate]

I want to monitor 2 of edge routers that currently have intermittent issue. I want to monitor their percentage availability using default ping parameter (1 ping per 1 second). If I run the ping ...
3
votes
2answers
403 views

How do I find the resident memory size of a process on busybox?

I run top on busybox and it shows all processes and their virtual memory size. How do I determine how much RAM is being used by each process?
2
votes
1answer
119 views

how to find out the full path of the command from the result of lsof -i

lsof is a great utility, just now started using it. lsof -i | grep smtp => this give the following result. httpd.pl 212548 global 3u IPv4 893092369 0t0 TCP ...
16
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6answers
5k views

Can ps display only non kernel processes on Linux?

How can I ask ps to display only user processes and not kernel threads? See this question to see what I mean...
3
votes
1answer
490 views

bash: disable new process PID message

It may look like this: [2] 2847. I guess the first digit is just an enumeration of processes created from the shell. The second is the PID. Anyway, I never care about that information so it is just ...
1
vote
1answer
33 views

What is the most Unix-y way to handle stdout for a backup command that might fail?

I am writing a utility/script (in Python, as it happens) to run on Linux, which backs up data from a remote server, and outputs to stdout. At the moment, I run this script on the hour from cron, and ...
1
vote
0answers
104 views

Stop all processes by a user: children of supervisord are still running

I'm trying to delete a user but it keeps saying that user is currently used by process ID x I tried everything here and here, nothing works, how do I kill all the process by a certain user in order ...
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0answers
18 views

How do kernel inform OSPF daemon when a physical interface status is down?

When a physical interface status is changed from up to down, there are 3 things related to the computer's current routing table and OSPF. The (connected) network for that interface and remote ...
7
votes
1answer
564 views

Why file-nr and lsof count on open files differs?

I am running into a problem all of a sudden; all my applications and the server was running fine and all of a sudden I see the number of open files shoot up. I am checking it with this command: cat ...
0
votes
2answers
982 views

What does “task mysqld:xxx blocked for more than 120 seconds” mean?

We are troubleshooting a MySQL issue where some queries are taking a very long time complete and I see many of these entry in /var/log/messages: Jan 28 05:52:15 64455-alpha01 kernel: [2529273.616327] ...
2
votes
1answer
70 views

Get total bytes sent by pid

I have some processes in my unix system that sends data to a remote machine. It is possible to fetch the total bytes sent per pid ? In general, how i can monitor that pid in terms of network? Thank ...