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

learn more… | top users | synonyms (1)

1
vote
3answers
107 views

What is the output of “du” command during a long copy?

Recently, I launched the cp command to create a backup of a big directory. So, I used a command like this: cp -rv big_directory new_location Because the files are big, it took a long time to ...
1
vote
1answer
35 views

Which process group does my program belong to when started from bash?

If I run a program from bash, then does my program belong to the same process group as the shell, or does it belong to a new process group? As I am making a shell in C, I need to handle the SIGINT ...
0
votes
3answers
92 views

Killing a comet zombie

I have a zombie process that is changing its PID, which is increasing. Is it possible to kill a process with PID greater than N?
1
vote
1answer
93 views

Killing PGIDs but proceses are respawning, how do I make it persistent?

I ran ps aux --forest -j to see parent and child processes. Here is an example: root 3744 3744 3744 0.0 0.2 77084 4160 ? Ss 09:34 0:00 /usr/sbin/cupsd -f lp 3747 3747 ...
1
vote
1answer
74 views

Is it better/preferred to kill all child processes by using PPID or PGID?

I need the ability to kill all child processes running under a particular parent. What would be the better option to do this? Using PPID or PGID? Something like this: pkill -TERM -P Would kill ...
1
vote
2answers
819 views

Why I can not use all the 100% potential of CPU?

I am using my computer clusters to run a MD C program but I can not use full potential of those clusters. But the this node have 16 CPUs and I also only give 15 jobs for those CPUs. But I can not ...
2
votes
0answers
31 views

Restrict a user from viewing other user's processes [duplicate]

Suppose there are two users : user1 & user2. Now we know that if I give top -u user1, I can see only the process respective to user1. But if I do top -u user2, I can see all the process running ...
0
votes
2answers
62 views

How to get PPID with PS using BSD options

I'm looking for a ps string that will give me all the output headers of "ps aux" but with the PPID. So far, I can only get the PPID column using ps -ef. I have tried numerous combinations but have ...
3
votes
4answers
63 views

Who forks the processes of piped commands in the shell?

Consider this command in the shell : ls|less Now we know that ls and less are run as two different processes. We know that the shell forks and creates a child process which load the ls program using ...
3
votes
3answers
65 views

How to start two processes piggie-backed? So the first finishes when the second finishes?

I'm running a script with ssh commands to a server behind a jump-host. Each time I want to run a command on my server in the secure network, I need to ssh into the jump-host (bastion) server and run ...
16
votes
1answer
294 views

Process which locks up, ignores SIGKILL, is runnable (not a zombie or in uninterruptable sleep). What state is it in?

I have a process which several times now has stopped responding and appears to be completely locking up. It doesn't respond to any attempt at strace or peeking with gdb (gdb just hangs on a wait4() ...
0
votes
0answers
78 views

Start a process from (noninteractive) shell script (cgi) and keep it running when script ends

I want a cgi script to start a process which stays alive after the cgi script exits. I tried: #!/bin/bash nohup process-to-keep-running & That works fine, if I run the script from an ...
3
votes
1answer
282 views

How to switch to other users's process?

A user has started a Java program and is currently running. As root, I can see it through ps -A. How can I bring this process to foreground?
0
votes
1answer
33 views

Open ports with no associated PIDs

I have some open ports on my laptop but netstat is not reporting which PID/Program is associated with them: $ netstat -tulpn (Not all processes could be identified, non-owned process info will not ...
0
votes
1answer
1k views

Linux ps -elf command output, what is Process Flag meaning?

In output of ps -elf command in linux, we can recognize that process flag of 4 and 1, and process flag of 5, (sum of 1 and 4), but what is meaning of process flag 0 ? unfortunately, man does not help ...
1
vote
2answers
31 views

Directory in /proc that isn't process dir but start with number?

Quick question. Is it possible to create directory in /proc that starts with number but isn't process directory (where name is PID)? I write software that searches for process directories and I wonder ...
4
votes
2answers
199 views

What does p and e denote in exec family of calls?

l and v in exec calls denote whether the arguments are provided via list or array(vector). I read it somewhere that p denotes the user's path and e denote the environment but did not understand what ...
1
vote
1answer
39 views

Restricting CPU time of processes by executable path

Is there a way to restrict CPU time (duration) for all processes which are invoked by executables that are located in a certain directory? I would like to be able to auto-kill all applications which ...
1
vote
3answers
150 views

What does it mean to run a process in background? [duplicate]

What exactly does it mean to run a process in the background? The difference between $program and $program&: Is it just that the input file descriptor is not inherited from the shell or is there ...
5
votes
2answers
298 views

Zombies in bash

Bash doesn't seem to create zombies. It looks like the processes get immediately reaped when they get killed. Can I make bash make zombies? Why I'm asking: I'd like to be able to safely kill a ...
3
votes
2answers
348 views

foolproof way to detect if java process is running

I have a java process that runs continually that sometimes, for reasons I have yet to fully debug, craps out. So, I also have a cron job that looks for the process every 5 minutes and if it finds the ...
3
votes
1answer
81 views

Resource (CPU time and memory) limitation and termination of a process upon violation in Linux

The problem: Given a process, limit the resources it and its child-processes can use. I.e. set CPU time and virtual memory quotas. When the process group exceeds one of the limits, terminate it, ...
6
votes
1answer
99 views

Is it possible to add a process to the job list in bash (e.g. to reverse “disown”)?

If I disown a job in bash and change my mind, can I undo it somehow ? If so, taking it further, is it possible to bring an arbitrary process under job control (an acceptable restriction would be that ...
1
vote
1answer
113 views

What is the actual process name when nautilus is copying files?

I am copying some files from an external drive to my desktop running Ubuntu. I can see the "File Operations" dialog which shows copying process. How do I find this particular process in ps aux | grep ...
3
votes
1answer
288 views

How can I know thread names that run on specific core

I am working in Java code. My code makes specific Java threads run on specific cores. In this code, I give names to Java threads. I need a Linux command that enables me to know the threads' names that ...
3
votes
1answer
121 views

How to kill a task that cannot be killed (uninterruptable?)

I have a task running that blocks pm-hibernate (on Linux 4.0.7-2). When I try pm-hibernate there is an error message "Freezing of tasks failed after 20.002 seconds (1 tasks refusing to freeze, ...
3
votes
1answer
161 views

Why can the waitpid system call only be used with child processes?

The man page wait(2) states that the waitpid system call returns the ECHILD error if the specified process is not a child of the calling process. Why is this? Would waiting on a non-child process ...
2
votes
2answers
109 views

How do I kill a process after detaching it from bash?

I have multiple scripts that detach a process from bash using nohup and &>/dev/null &. My question is, how do I kill the process after completely detaching it from bash. using killall or ...
0
votes
1answer
56 views

Process command

When I used ps -u root command in Ubuntu it showed the following output? PID TTY TIME CMD 1 ? 00:00:02 init 2 ? 00:00:00 kthreadd 3 ? 00:00:00 ksoftirqd/0 5 ? ...
2
votes
0answers
52 views

Find which process is being joined by another?

If I have opened Nautilus and spawned a new Nautilus instance, a new PID is created for the new Nautilus instance. Shortly after, the instance is joined with the main Nautilus program running. Main ...
1
vote
1answer
93 views

Is there a robust way for a child process to signal readyness to its parent? [closed]

I have a (Java) process which is staring a separate process foo. foo takes some number of seconds to start up, then is really running. Control returns back to the parent process as soon as foo is ...
3
votes
2answers
147 views

bash + how to hold shell scripts

Is it possible to hold/stop the bash script progress without to kill the process? ( by kill command ) or other command For example this script - install_linux_pkgs.bash , will install Linux pkgs ...
21
votes
1answer
717 views

What does it mean to have a minus sign as the first character of a command in htop output?

In htop, or other commands that show process status, all bash processes have in the command column /bin/bash but one process has in the command column -bash What does it mean?
1
vote
1answer
104 views

Why does my process take too long to die?

Basically I'm using Linux 2.6.34 on PowerPC (Freescale e500mc). I have a process (a kind of Virtual Machine that was developed in-house) that uses about 2.25 G of mlocked VM. When I kill it, I notice ...
2
votes
1answer
381 views

list processes belonging to a network namespace

I am on Ubuntu 12.04, and the ip utility does not have ip netns identify <pid> option, I tried installing new iproute, but still, the option identify doesn't seem to be working!. If I were to ...
1
vote
0answers
20 views

Inconsistent output on /proc. Can some processes be hidden? [duplicate]

When I list /proc/<PID>, works as expected. But when I use ps or ls /proc | grep <PID>, the process is hidden. How & Why is this possible? [user@host ~]$ ls /proc/12263 attr ...
9
votes
1answer
1k views

Still alive, still alive after kill -9 / SIGKILL [duplicate]

An apache2 process got stuck on my server and caused problems with other services. (original problem: kerneloops after USB hardware disconnect) root@server:~# ps aux | grep apache2 | grep -v grep ...
2
votes
1answer
104 views

Process startup after boot

I know the following are ways processes get started in Linux from init.d (or similar) from shell (by user) forked by a running native daemon Is it ever possible on Linux for a process to be ...
2
votes
2answers
125 views

Why is the range of load average not 0-1+ for all cpu's together?

I know that load average is 0-1(or 0-1024) per cpu. E.g a busy quad-core can have a load average of 4.0 or higher. (e.g if there are many tasks). I understand it can be huge like 100+ etc. I also ...
1
vote
1answer
45 views

How can I find out which mounted filesystems a running process sees?

After having a long debug session and finally finding out that in Fedora (and CentOS) php-fpm has its own mounted /tmp filesystem, which was caused by a systemd setting, PrivateTmp, I am wondering if ...
0
votes
0answers
26 views

Page Fault Frequency Algorithm - Compute number of frames and mean resident set

I'm reading about Page Fault Frequency algorithm but I don't understand how can I compute the number of frames. For example I have my reference string: 112233444412412214432255543 and control ...
9
votes
1answer
100 views

Is it possible to know the source (application) of the clipboard?

I've noticed that sometimes clipboard contents become unavailable if the source application (where the content was copied from) is closed. This leads me to wonder if it's possible to know what the ...
0
votes
1answer
68 views

Kernel current working directory and inode information placement

I'm reading some doc about UNIX but I don't understand two things: Why is important for the kernel to know the current working directory of the running process? Why not keeping the inode information ...
2
votes
6answers
387 views

How to close all proceses without restarting a machine?

I have a lot of processes running and I need to kill them all. How can I do this without restarting a machine?
1
vote
1answer
53 views

Stopping jobs by PID?

Could someone tell me why I am unable to kill the jobs below when specifying their PID? I can stop the jobs when using their % id. Mac:~ gd$ ps PID TTY TIME CMD 4523 ttys000 0:00.02 ...
3
votes
1answer
70 views

Sending signals to long-running processes (AWK, DD)

I'm familiar that DD command doesn't produce output while running. However, if I send a USR1 signal to it, it can print current state. Can I do the same with AWK? Prints its variables, register ...
1
vote
1answer
198 views

Show CPU core usage for parent process and its child processes

Is it possible to display CPU core usage just for a single process and its child processes on Linux?
3
votes
2answers
85 views

Sum the memory usages of all the processes of a program?

How can we sum the memory usages of all the processes of a program? For example, I have opened many Chrome tabs for webpages, and each tab runs a different process. How can I get the total sum of ...
4
votes
2answers
705 views

How to locate a Chrome tab from its process PID?

I opened many Chrome tabs for webpages. Each tab has its own PID, e.g. USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND t 3900 1.9 6.3 5718440 508660 ? Sl ...
2
votes
1answer
32 views

How to guard a set of folders from being written into by a specific process?

I would like to have a way in which a set of folders do not allow write access for a particular process. For example, I would love to have a way in which YUM/RPM is not allowed to write into /usr/bin ...