What is the command to display currently running processes and the option to display PPID's?
I thought that it might be:
jobs -p
jobs -pl
Neither worked though. Any hints?
ps -ef will display all processes and include PPIDs.
it really depends on what you're after
you usually use
top
to see how processes consume system resources
however, if you just want to see some process pid, and know some word from the command that used to run it, try:
ps -ef | grep java
there are other (many) commands and tools, it really depends on the reason you look for the process
for getting one using your username: top -u username idk how to do it with ps but that would be nice to know.
Related
I need to display processes, that are running in specific folder.
For example, there are folders "TEST" and "RUN". 3 sql files are running from TEST, and 2 from RUN. So when I use command ps xa, I can see all processes, runned from TEST and RUN together. What I want is to see processes, runned only from TEST folder, so only 3. Any commands, solutions to do this?
You can use lsof for this.
lsof | grep '/path/of/RUN'.
If you want to include both RUN and TEST in same command
lsof | grep -E "/path/of/RUN|/path/of/TEST"
Hope it helps.
You can try fuser to see which processes have particular files open; or, on Linux, examine the /proc/12345/cwd symlink for each of the candidate processes (replace 12345 with the process id of each).
fuser TEST/*.sql
for proc in /proc/[1-9]*; do
readlink "$proc/cwd" | grep -q TEST && echo "$proc"
done
The latter is not portable to other U*xes, though some may offer similar facilities.
I've googled this question, but never found anything useful for my particular case.
So, what I'm trying to figure out is the PID of a certain command that is running so I can kill it if necessary. I know it's possible to get the PID of a command by typing echo $! So supposedly
my_command & echo $!
should give me the PID. But this isn't the case, and I think I know why:
My command is as follows:
screen -d -m -S Radio /path/to/folder -f frequency -r path/to/song
which opens a detached screen first and then types the command so that it gets executed and keeps on running in the background. This way the PID that echo shows me is the wrong one. I'm guessing it shows me PID of screen -d -m -S Radio /path/to/folder -f frequency -r path/to/song instead of the PID of the command run in the new terminal created by screen.
But there's another problem to it: when I run screen -ls in the terminal, the command that is running in the background doesn't show up! I'm fairly certain it's running because the Pi is constantly at 25% CPU usage (instead of the 0% or 1% usually) and when I type ps au I can actually see the command and the PID.
So now I'm calling the community: any idea on how I could find the PID of that certain command in the new terminal? I'm writing a bash script, so it has to be possible to obtain the PID through code. Perfect would be a command that stores the PID in a variable!
Thanks to #glennjackman I managed to get the PID I wanted with a simple pgrep search_word. At first it wasn't working, but somehow I made it work after some trial and error. For those wanting the PID on a variable, just type
pid=$(pgrep search_word)
Regarding the problem with screen -ls not showing my detached session, it's still not solved, but I'm not bothered with it. Thanks again for solving my problem #glennjackman !
EDIT:
Second problem solved, check the comments on berends answer.
You can easily find out all the running process and their PID by writing (for example):
ps aux
The process is run by screen so you can probably find it easier by writing:
ps aux | grep screen
For more info about ps and the parameters I used check (quick google) -> https://www.lifewire.com/g00/uses-of-linux-ps-command-4058715?i10c
EDIT: You can use this command with bash scripting as well.
I am very new to shell scripting, can anyone help to solve a simple problem: I have written a simple shell script that does:
1. Stops few servers.
2. Kills all the process by user1
3. Starts few servers .
This script runs on the remote host. so I need to ssh to the machine copy my script and then run it. Also Command I have used for killing all the process is:
ps -efww | grep "user1"| grep -v "sshd"| awk '{print $2}' | xargs kill
Problem1: since user1 is used for ssh and running the script.It kills the process that is running the script and never goes to start the server.can anyone help me to modify the above command.
Problem2: how can I automate the process of sshing into the machine and running the script.
I have tried expect script but do I need to have a separate script for sshing and performing these tasksor can I do it in one script itself.
any help is welcomed.
Basically the answer is already in your script.
Just exclude your script from found processes like this
grep -v <your script name>
Regarding running the script automatically after you ssh, have a look here, it can be done by a special ssh configuration
Just create a simple script like:
#!/bin/bash
ssh user1#remotehost '
someservers stop
# kill processes here
someservers start
'
In order to avoid killing itself while stopping all user's processes try to add | grep -v bash after grep -v "sshd"
This is a problem with some nuance, and not straightforward to solve in shell.
The best approach
My suggestion, for easier system administration, would be to redesign. Run the killing logic as root, for example, so you may safely TERMinate any luser process without worrying about sawing off the branch you are sitting on. If your concern is runaway processes, run them under a timeout. Etc.
A good enough approach
Your ssh login shell session will have its own pseudo-tty, and all of its descendants will likely share that. So, figure out that tty name and skip anything with that tty:
TTY=$(tty | sed 's!^/dev/!!') # TTY := pts/3 e.g.
ps -eo tty=,user=,pid=,cmd= | grep luser | grep -v -e ^$TTY -e sshd | awk ...
Almost good enough approaches
The problem with "almost good enough" solutions like simply excluding the current script and sshd via ps -eo user=,pid=,cmd= | grep -v -e sshd -e fancy_script | awk ...) is that they rely heavily on the accident of invocation. ps auxf probably reveals that you have a login shell in between your script and your sshd (probably -bash) — you could put in special logic to skip that, too, but that's hardly robust if your script's invocation changes in the future.
What about question no. 2? (How can I automate sshing...?)
Good question. Off-topic. Try superuser.com.
I'm working on a project similar to what we call system monitor in Linux. I'm using opensuse 11.4 gnome. I was wondering if there's any command (Except ps) that lists all currently running applications on the system. I'm developing it for multi-core environment.
For example I'm browsing the web with Firefox and lets say Google Chrome simultaneously, plus I'm editing text in a text file. In this scenario, when I open my project, I want the list of all applications currently running [in my scenario, the names gEdit, Google Chrome and Firefox(but not the process these three apps generated) must be displayed as a list]
The output I want is the same as what we get in the Applications tab when we use task manager in Windows.
If anyone has a solution, please let me know it'll be highly apprecieted. I'm using netbeans to implement the project. Thanks!!!
I don't think there is a easy way of getting this done. In Linux an application may create several processes on startup - for example let's take postfix:
localhost:~ # ps -ef|grep postfix
root 3708 1 0 Apr24 ? 00:00:35 /usr/lib/postfix/master
postfix 3748 3708 0 Apr24 ? 00:00:01 qmgr -l -t fifo -u
postfix 3749 3708 0 Apr24 ? 00:00:00 pickup -l -t fifo -u -c
postfix 13504 3708 0 16:05 ? 00:00:00 cleanup -z -t unix -u -c
postfix 15458 3708 0 17:45 ? 00:00:00 cleanup -z -t unix -u -c
postfix 19907 3708 0 19:25 ? 00:00:00 cleanup -z -t unix -u -c
the processes "master", "qmgr", "pickup" and "cleanup" all belong to the application postfix. You can see that those processes each belong to one parent process "master" by looking at the third column which tells you the parent process who has startet this process. In my example all processes have been startet by process with id 3708. Another example is the Apache Webserver, which creates several httpd processes on startup - here the process names are all the same only the count varies depending on the configuration.
To come back to the problem you would like to solve: From my point of view there are two ways you could try:
Build up a database which contains associations of processes names to applications and use this to create your list of applications by using ps.
You restrict your application to list only applications which display a graphical user interface. This list should be easily build by using some X11 functions or the likes...
hope this helps...
Have you tried pstree yet? well this shows you a tree of the processes that are running on the system.
htop is what I usually use for multicore enviornment cause it shows resource utilization and you can see where your processes are pinned by adding columns. htop is more userfriendly than top and has more options. when you run it just hit 't' and it will sort the processes by their parents.
I don't know any other tools, but your other option is to go through /proc and write your own script to extract the information you need.
I hope it helps.
EDIT: I forgot to mention that processes are being forked in linux, so there is a parent process which starts a couple of other processes/threads. From your question, it seems that you are trying to find the parent process for each running process, my answers are based on that assumption.
Check out top (linux command)
And this article will help you a lot.
http://www.cyberciti.biz/tips/top-linux-monitoring-tools.html
You may want to start from xlsclients.
It probably does not have all the functionality you need, but then Linux has no well-defined notion of application.
The next thing you might find useful is xprop (look for _NET_WM_PID) but this is not guaranteed to work for all programs.
How would I track the CPU and Ram usage for a process that may run, stop, and then re-run with a different PID?
I am looking to track this information for all processes on a Linux server but the problem is when the process stops and restarts, it will have a different PID and I am not sure how to identify it as the same process.
What you're looking for here is called "process accounting".
http://tldp.org/HOWTO/Process-Accounting/
If you know the command of the process, just pipe it to a grep like this:
ps ux | grep yourcommandgoeshere
You can setup a crontab to record output of commands like
top -b -n1 | grep
ps ux | grep
Alternatively, you can use sealion service. By simply installing agent and configuring it according to your needs in simple steps, you can see output of the executed commands online.
Hope it helps...