CPU utilization for given command in Linux - linux

For generic commands in Linux like htop, ping, who, scp etc.
how to know how much % of CPU is being used when they were executed?
are there any Linux tools which can give the stats for above commands!

while top is running:
press o to open filter options
type COMMAND=your-script-to-monitor
for htop:
press F4 to filter by command name
type in your command
From here, you can check the CPU% column

You can try also this:
ps -p <PID> %cpu

Related

Count active processes in Linux Terminal

I'm looking for 2 Ubuntu terminal commands that will:
Show currently running processes (or tasks).
Count how many currently running processes (or tasks) there are.
I am windows user and I'm not sure if it's named tasks or processes, but I'm looking for the same thing that's displayed when I open windows task manager.
It's very easy using the ps utility. That will return a list of
PID: Process identification number.
TTY: The type of terminal the process is running on.
TIME: Total amount of CPU usage.
CMD: The name of the command that started the process.
You can also combine/pipe it with wc to count the lines produced by it, hence counting the number of processes, like this:
$ ps -e | wc -l
You can find more info here and here.

How to find the PID of a running command in bash?

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.

Find ProcessorId and Cpu Usage of all running processes

Background
I want to find the cpu core id and utilization of each and every process running in my system.
I have used ps -eF to get cpu core id and ps -aux to get cpu utilization.
Query
I want to know, is there any way to get both the things using a single command or any specific options that is available in ps command to retrieve both the things?
You can add the -o option to your ps -ef to add additional columns to the output. The format specifiers are documented in the ps man page in the Standard Format Specifiers section.
For example:
ps -efo %cpu or ps -efo pcpu
Additionally, you can run this command to list all valid format specifiers:
ps L

Linux display currently running processes

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.

How to log the Ram and CPU usage for Linux Processes

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...

Resources