Linux: Reading Process Information

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Del curso dictado por Google

Operating Systems and You: Becoming a Power User

3729 calificaciones

Google

Operating Systems and You: Becoming a Power User

3729 calificaciones

Curso 3 de 5 en SpecializationGoogle IT Support Professional Certificate

In this course -- through a combination of video lectures, demonstrations, and hands-on practice -- you’ll learn about the main components of an operating system and how to perform critical tasks like managing software and users, and configuring hardware. We’ll wrap up with an example of how you might see this content show up in an interview setting. By the end of this course you’ll be able to: ● navigate the Windows and Linux filesystems using a graphical user interface and command line interpreter. ● set up users, groups, and permissions for account access. ● install, configure, and remove software on the Windows and Linux operating systems. ● configure disk partitions and filesystems. ● understand how system processes work and how to manage them. ● work with system logs and remote connection tools. ● utilize operating system knowledge to troubleshoot common issues in an IT Support Specialist role.

De la lección

Process Management

In the fifth week of this course, we'll explore process management. As an IT Support Specialist, it is important to use system tools to read and understand process statuses of machines. We will cover ways to start and terminate a process in Windows and Linux. We will also apply troubleshooting tools to solve problems with processes and resources. By the end of this module, you will use Windows and Linux commands to do practical process maintenance.

Windows: Reading Process Information3:42

Linux: Reading Process Information4:13

Windows: Signals1:52

Linux: Signals1:12

Windows: Managing Processes5:00

Linux: Managing Processes4:12

Conoce a los instructores

Google

Okay, now let's talk about how to view the processes running on our system in Linux.

We'll be using the ps command, so let's just go ahead and

run that command with the dash X flag, and see what happens.

This shows you a snapshot of the current processes you have running on your system.

The ps output can be overwhelming to look at at first, but

don't worry, we'll walk through how to read this output.

Let's start from right to left here.

P-I-D or

PID is the process ID, remember processes get a unique ID when they're launched.

TTY, this is the terminal associated with the process,

we won't talk about this field but

you can read more about it in the manpages linked right after this video.

STAT this is the process status,

if you see an R here it means the process is running or it's waiting to run.

Another common status you'll see is T for

stopped, meaning a process that's been suspended.

Another one you might see is an S for interruptible sleep,

meaning the task is waiting for an event to complete before it resumes.

You can read more about the other types of process statuses in the manpages.

TIME, this is the total CPU time that the process has taken up.

And lastly, command, this is the name of the command we're running.

Okay, now we're going to enter hard mode here.

Run this command, PS-EF.

The E flag is used to get all processes, even the ones run by other users.

The dash F flag is for full, which shows you full details about a process.

Look at that, we have more processes and even more process details.

Let's break this down.

UID is the user ID of the person who launched the process.

PID is the process ID, and PPID is the parent ID

that we discussed in earlier lesson which launched the process.

C is the number of children processes that this process has.

STime is the start time of the process.

TTY is the terminal associated with the process.

TIME is the total CPU time that the process has taken up.

And CMD or command is the name of the command that we're running.

What if we wanted to search through this output?

It's super messy right now,

can you think of a way we can see if a process is running?

That's right,

with the grep command, I told you we were going to use it all the time.

This will give us a list of process that have the name Chrome in them.

There's another way to view process information,

remember everything in Linux has a file, even processes.

To view the files that correspond to processes we can look into slash proc

directory.

There are a lot of directories here for every process that's running.

If you looked inside of one of the subdirectories it'll give you even more

information about the process.

Let's look at a sample process file for PID 1805.

This tells us even more information about a process state than what we saw in PS.

While the slash proc directory is interesting to look at,

it's not very practical when we need to troubleshoot issues with processes.

For now stick with the PS-EF command to look at process information.

As you can see, we can learn a lot about the processes running on our

machine with just a few key strokes.

In an upcoming lesson we'll talk about how to use process information to our benefit

when figuring out which processes are taking up too many resources.

For now, feel free to learn a little more about the processes that you're running,

I'll be waiting for you in the next video.

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