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

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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
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3answers
54 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 `$ ...
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1answer
65 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 ...
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3answers
68 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
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9answers
16k 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 ...
98
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7answers
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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 ...
27
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6answers
46k 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 ...
77
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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
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1answer
35 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
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1answer
146 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 ...
34
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5answers
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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
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2answers
174 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
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1answer
81 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
4k 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
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1answer
453 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
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1answer
31 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 ...
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0answers
71 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
14 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
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1answer
225 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
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2answers
463 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
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1answer
53 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 ...
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1answer
49 views

Is there a way to change the number of processors a program sees?

Is there any way I can trick a program into thinking the system has fewer processors? To explain: I am debugging a program that creates as many threads as it has processors, using ...
3
votes
1answer
25 views

Identify in which screen instance a process is running

A process listening on port 8113 (Solr) is not responding. I've found its PID via netstat but the server has about two dozen Solr process running in various screen sessions. 3607.foobar-client2 ...
37
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3answers
3k views

How can I check what signals a process is listening to?

How can I verify whether a running process will catch a signal, or ignore it, or block it? Ideally I'd like to see a list of signals, or at least not have to actually send the signal to check.
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2answers
228 views

ls -l /proc/self | increamental PID?

Each time, when the commandls -l /proc/self is executed, the link points to process who's PID keeps increasing. Why is this so ? Is it the PID of the ls command ?
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44 views

Serial port locked by random process

I have an issue with trying to open a USB device's serial port with pyserial. It seems that as fast as I connect the device, /dev/ttyACM0 is used by some random process. ModemMana 851 root 8u ...
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2answers
64 views

start process (as root) upon user login

I would like to start a process as root upon each user login. The motivation beside this is, that the process will work on encrypted home folder of particular user folder. How can I achieve this?
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1answer
261 views

How to do a netstat that will only filter based on pid

How can I have the following command below just show/filter based on the PID's I'm looking for? sudo netstat -lp --inet The results come back as this Proto Recv-Q Send-Q Local Address ...
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2answers
42 views

How do Linux PIDS increment

Why do PIDS under Linux (generally) increment by 4? The only exception I can think of is startup processes run by systemd, which increment by 1 when they are related or 2 otherwise. How was the ...
2
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0answers
66 views

“Restart” a process in the same terminal?

I put "restart" in quotes because the following question on SO illustrates what I'm trying to do: http://stackoverflow.com/questions/27957091/restarting-a-process-in-the-same-linux-terminal I'm ...
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2answers
70 views

do processes access cpu and memory by system calls to the kernel?

If I am correct, processes access devices by system calls to the kernel. CPU and memory are also devices. when a process starts to run, does it get cpu and memory by system calls to the kernel? ...
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1answer
72 views

Count the total number of sub-processes (recursively) spawned by a command

How do find the total number of child processes (recursively) spawned by a script? For profiling purposes, it is sometimes important to count the generated sub-processes of command, script, etc. ...
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2answers
4k views

When was a process started

To know when was a process started, my first guess was to check the time when /proc/<pid>/cmdline was written/modified the last time. ps also shows a START field. I thought both of these ...
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0answers
86 views

Monitor the creation of new processes

I want to get a notification whenever a new process is created. I've tried to use inotify on /proc, but it didn't report any event even though a new directory appeared in /proc. I could list the ...
1
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1answer
119 views

Why cannot we kill a zombie? [duplicate]

I am editing this question since it was marked duplicate as another question about how to kill a zombie process. I am not looking for an answer to how to kill a zombie process. I do not have zombies ...
5
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4answers
683 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?
2
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1answer
3k views

What is the difference in CPU utilization between 'ps aux' and 'ps -ef'?

I use Ubuntu 12.04.1 Linux. I see a difference between %CPU and C output format of ps command for a process. It is not clearly noted in the ps man page. Man pages says: CODE HEADER ...
2
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0answers
45 views

What uses Linux “application memory”?

Just for fun, I wanted to watch what ls -lR / does to my "buffers" memory on a Linux system. As expected, the value increased. But I noticed that the "application memory" (i.e. "used" - (buffers + ...
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6answers
894 views

grep invading my ps [duplicate]

When I'm checking for some process, I usually write ps aux | grep myprocess And sometimes I get the output of eimantas 11998 0.0 0.0 8816 740 pts/0 S+ 07:45 0:00 grep myprocess if ...
3
votes
1answer
1k views

Program stall under user but runs under root

I am running R job under a normal user john and root. Interestingly, the program stalls under john user but runs quickly under root. Using strace, I found that when john runs the R, the process stalls ...
5
votes
1answer
6k views

What is kondemand?

I have searched the web for the answer of this question but couldn't find a clear answer. Best answer I found was as follows: kondemand is a kernel thread that belongs to the ondemand governor of ...
2
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1answer
128 views

“incrond dead but subsys locked” what does it mean?

While running "service incrond status" it shows "incrond dead but subsys locked". Can you please tell me what does it means. Normally its status should be running. Let me know what may cause it to ...
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1answer
89 views

fork() and how signals are delivered to processes

I program that I wrote in C fork()'s off a child process. Neither process will terminate. If I launch the program from the command line and press control-c which process(es) will receive the interrupt ...
2
votes
1answer
84 views

Equivalent command for ``time`` for memory usage?

by using time we can easily get the information about how long a program run, I was wondering if there is any equivalent command I can use for memory usages? Like how many memory are allocated for ...
2
votes
1answer
121 views

Bash update list of running jobs with ps

I need to run in parallel a set of computationally intensive tasks. What I was trying to do is to maintain a list of pids corresponding to the running jobs and update the list of running jobs with ps ...
2
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5answers
665 views

How to kill stubborn process

I've an annoying process that won't die: ps -A | grep "nzbget" gives me: 11394 pts/3 00:00:00 nzbget If I try: pkill nzbget (or 11394) ...I get no response and the process is still alive, ...
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1answer
2k 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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2answers
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A process is a program that is loaded into RAM [closed]

Is this correct? Basically, programs are simply code on hard disk and they are called process(es) when they are in the RAM, right?
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2answers
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Can Process id and session id of a daemon differ?

As far as I understood from different articles and here , a daemon has the following features: Parent Process ID should be 1. No terminal should be associated with the process. The process id, ...