ps is a command for printing information about running processes

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86 views

Is there any risk of a race condition when runing ps?

I'm starting a long-running process (in Java, on the off-chance that's relevant) and would like to then capture its PID via ps. I'm essentially doing this: Process longRunningProcess = new ...
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2answers
26k views

Please explain this output of ps -ef command?

A part of the output from the ps -ef command is given below : UID PID PPID C STIME TTY TIME CMD root 1 0 0 2012 ? 00:00:01 init [3] root 2 ...
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3answers
7k views

Why is apache2 showing up a defunct in the process list?

When I run top I see one line that doesn't look too good: 2475 www-data 20 0 0 0 0 Z 1 0.0 0:00.19 apache2 <defunct> Why is this process <defunct> and what should I ...
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4answers
253 views

Single instance of script, but only with same arguments

I have this beautiful little code here that will exit from a script if there's another instance of it running: single_instance(){ if pidof -x "${0##*/}" -o %PPID >/dev/null; then exit ...
4
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1answer
183 views

What is the meaning of “1-” in the output of ps?

This is the output of the command ps -ef | grep java on one of our machines. jboss 1965 1935 1 2013 ? 04:41:05 java XXXXXXXXXXXXXXXXX jboss 2170 2141 0 2013 ? 00:42:57 ...
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3answers
6k views

How to get whole command line from a process?

How can I get the command arguments or the whole command line from a running process using its process name? For example this process: # ps PID USER TIME COMMAND 1452 root 0:00 ...
4
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2answers
4k views

What does a “[1]+ Exit 1” response mean?

I ran this command to try and get my python program to run in the background and let me exit the SSH connection I am using: nohup python files.py >> files.log & I then check ps to check ...
4
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3answers
131 views

How to show quoted command list?

ps -o command shows each command on a separate line, with space separated, unquoted arguments: $ ps -o command COMMAND bash ps -o command This can be a problem when checking whether the quoting was ...
4
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2answers
703 views

How to list all running X applications?

I'd like to get a list of all of the apps (across all users) on my machine that are talking to the X server. What's the most reliable way to do that? Find the socket X runs on and lsof for connections ...
4
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2answers
446 views

process Count of each user in ps aux command

How can i create a script to count process run by each user in ps aux. I used this ps aux | awk '{print $1}' | grep root | wc -l but it lists count of root user only . I want to list number of ...
4
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3answers
2k views

Format ps output without whitespace

I have the following ps command to get particular properties of all the running processes along with some properties: ps --no-headers -exo "uname,ppid,pid,etime,%cpu,%mem,args" I wish to have it ...
4
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1answer
830 views

PS: what does “ps -o comm= -p $PPID” do

I have a script which does ps -o comm= -p $PPID. The explanation says this gets the parent process name. From the man page I found out -o means user defined format, comm means command and -p means ...
4
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1answer
10k views

Understanding ps elapsed time format for long running processes

I'm using a ps command as part of an exercise to identify processes running longer than a given threshold. I'm using the following template to get the elapsed time for a know process command: ps -eo ...
4
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3answers
59 views

How do I get the first branch PID of an application in pstree command?

I want to get PPID of chromium browser. When I launch chromium-browser it launches many child processes with the same name. For example: $ pidof /usr/lib/chromium-browser/chromium-browser 8963 ...
4
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1answer
177 views

ps wide output for a single process

The ps command has a ww output modifier (man page says this is "wide output, unlimited length"). This modifier seems to not work if prefixed with a hyphen (-ww) AND ps reports on a single process ...
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2answers
6k views

How to find out total memory resource usage with ps?

With ps command I can find out how much memory each program uses: ps -u mertnuhoglu -o pcpu,rss,pid,command Is it possible to find out the sums of each type of resource usage as well, easily?
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2answers
56 views

How do I find the PID of a particular program?

I would like to write a Bash script that searches for PIDs matching a program's name (perhaps using ps ax | grep <PROGRAM> or something similar) and feeds them to pixelb's ps_mem script. ps_mem ...
4
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1answer
96 views

Why does a process of a binary with only execute permission remain hidden in “ps” when using hidepid=2, if the user is not root?

I'm using hidepid=2 to mount /proc, so users can't see any but their own processes. A particular binary I want to use has been restricted to rwx--x--x permissions, so only its owner (root) can read it ...
4
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1answer
66 views

-p option of ps

If one omits the -p option in the the ps in Linux, it is implied if a number is given. man ps says 123 Identical to --pid 123. and --pid pidlist Select by process ID. ...
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2answers
3k views

Convert PDF from sRGB color space to CMYK

Does anyone know how I can convert a PDF (or EPS) file from sRGB color space to CMYK color space? My workflow is currently the following: Draw an image with Powerpoint Print via postscript printer ...
4
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1answer
152 views

Get process list with logical intersection of selectors?

The Linux ps command allows multiple selectors, such as user and command name, but always returns the logical OR of those selectors (more than I want). Does anyone know of a method or tool already ...
4
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1answer
12k views

Among “ps” command output fields, %CPU isn't the actual CPU usage of the process?

For example, one of the output fields of this BSD style command, ps aux, is "%CPU". The alternative command, ps -efl outputs the "C" (or CP) field. As per the ps man page: %CPU is the cpu ...
4
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1answer
636 views

How does ps get the executable of processes of other users?

When running as non-root, if I try to use readlink(2) on a /proc/<pid>/exe for a process not owned by me I get a permission error. So how then does ps with the -f option, which isn't setuid ...
4
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1answer
6k 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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0answers
166 views

What processes are used by DRM?

Whenever some content is DRM-protected, screenshots of such content are masked. Even using Terminal does not avoid such problems. Which processes in ps ax are used by DRM that is implemented by ...
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2answers
2k 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 ...
4
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3answers
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Uniquely identifying java processes with same name

I have two java processes which run using the same file name, MyApp.jar (for example). /usr/java/latest/bin/java -jar MyApp.jar These jars exist in different places and use different ...
3
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3answers
14k views

What is the difference between ps and top command?

What is the difference between ps and top command ? I see that both can display information about running processes . Which one should be used when ?
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4answers
2k views

How to run java process to be seen not as 'java…' in processes list?

Is it possible to run a Java process in Linux in a way that it could be seen in ps as some sort of alias? It would be easier to restart it when it is down.
3
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1answer
1k views

UNIX-, BSD-, GNU-options in Linux's ps command. Where are they from? [closed]

In the manual for the ps command on Ubuntu there is this text: This version of ps accepts several kinds of options: 1 UNIX options, which may be grouped and must be preceded by a ...
3
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2answers
384 views

How to make sure the shell builtin echo is invoked so that its not visible in process list?

Is this going to be visible in the process listing if the below line is executed from a command line or a shell script bash -c "echo $password" or i just need to do echo $password from within ...
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6answers
12k views

How do use awk along with a command to show the process ID with the 'ps' command

I'm able to to show the PID (2nd) column with the below command, but instead I want to show pwdx <PID> and also the COMMAND(8th) column. Thanks in advance, Chirag ps -ef | grep runner | awk ...
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2answers
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Frequently used “ps” (process status) commands in linux? [closed]

EDITED: These are the the only most commonly used (and important) ps command options I've come across so far: $ ps ux, $ ps au, $ ps aux, $ ps U aahan, $ ps uU aahan So, is that all, or am I missing ...
3
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1answer
2k views

What is the meaning of ps process names printed in [] such as [cgroup]? [duplicate]

when I do a command such as ps -aux on CentOS 6 I get a bunch of processes whos command is listed in [] as shown below. What is the meaning of the [] in the name? I am assuming that these are special ...
3
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1answer
161 views

Sorting the output of ps does not work

I want to sort the output of the following command based on pcpu: ps -p 29492 -L -o pid,tid,psr,pcpu I tried the following: ps -p 29492 -L -o pid,tid,psr,pcpu --sort=pcpu But it doesn't seem to ...
3
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3answers
103 views

How to get the pid to the last background app

Following from this question: How to get the pid of the last executed command in shell script? The thread there is good and clear, but what if the command actually doesn't require a '&' at the ...
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2answers
400 views

Select lines starting with specific numbers

I have to show the PID, PPID and STATUS of the procceses on the system, but only the ones which PID starts with numbers in the range 5-8. So i tried something like this... ps xao pid,ppid,s | grep ' ...
3
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2answers
2k views

How to list only non-<defunct> processes?

Is there a combination of command-line options for ps or pgrep or some other relatively direct way to determine if a particular process name is actually running (available for normal use).. By ...
3
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2answers
2k views

Sorting the output of `ps`

I am trying to understand why ps does not behave the way I expect it to. From the man pages, the following command should display ppid and lstart, with items sorted by lstart order. However when I run ...
3
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2answers
3k views

How to count how many shell/terminals are running?

I´m trying to count how many shell or terminal windows are currently running. I tried ps a|grep bash; ps a|grep tty; But it can be inaccurate.
3
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1answer
402 views

Enumerating\writing files in a specific directory hangs the command

I'm communicating with a machine remotely through ssh. This machine runs a custom-built Linux and it has very limited set of commands. At some point, a specific directory refuses files to be written ...
3
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2answers
766 views

Why can't pgrep find scripts started via env?

For example: $ cat foo.sh #!/usr/bin/env bash while true; do sleep 1 ; done $ ./foo.sh & $ pgrep foo.sh $ Contrast with: $ cat bar.sh #!/bin/bash while true; do sleep 1 ; done $ ./bar.sh & ...
3
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1answer
58 views

-p and -o comm doesn't work together?

I'm trying to get CPU usage of a process by, ps -p 12990 -o comm=comm,pcpu But that only print the command name (the process does exist), what's wrong with it?
3
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2answers
54 views

How can I kill process by specific name and exclude root processes

Not a long time ago we found out about pkill and we had in mind to start using it in a setuid (for root) script for global clean-up of processes. This could save us lots of stupid maintenance where ...
3
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1answer
71 views

How to sort ps output to find processes realtime priority and identify processess currently occupied running queue

How to properly identify real-time processes currently occupied CPU queue and count them using ps? I know there is a bunch of fileds like prio,rtprio,pri,nice but do not know correct to use. It seems ...
3
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2answers
41 views

How to find what processes run by the user right now?

Once again, I'm a beginner and I can't find the right command. I want to view the processes that I'm currently running.
3
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1answer
474 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
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1answer
131 views

Grepping a variable

I've written a simple init script to start and stop a Python script as a service. I have to be explicit about the version of Python I'm running, because this is on a CentOS 5 box with Python 2.4 & ...
3
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2answers
983 views

How to set what field names are displayed in listings?

When I execute a command in Ubuntu, which results in a listing, I get results without the field names. Example is ls -l or ps l. I am not very experienced and always need to go digging through man ...
3
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4answers
1k views

Capture complete process structure/stack

There are a lot of java processes running on the server, generally, we capture the PIDs of the java processes using command 'ps -ef | grep java'. In general, the java processes have a lot of jars in ...