Managing Processes

In Task Manager if you click on the processes tab, you should see a list of

the processes that the current user is running along with a few of the system level processes that the user can see.

In Process Explorer, if you right-click on a process, you'll be given a list of

different options that you can use to manage the process. Kill Process, Kill Process Tree, Restart, and Suspend.

ps -ef command does what (Linux)

e = get all processes even the ones used by other users f = full, which shows you full details about a process.

To kill a process, you can select any of the process rows and click the

end task button in the lower right corner.

To look into a subdirectory what do we do (Linux)

ex: cat /proc/1805/status This tells us even more information about a process state than what we saw in PS.

If you don't give the process a chance to clean up some of the files it was working with, it could cause (Linux)

file corruption. kill dash kill is a last resort to terminating a process.

The app that we're using is called the

foreground app

What if we wanted to search through this output what command would we use? (Linux)

grep ex: ps -ef | grep Chrome This will give us a list of process that have the name Chrome in them.

On the Windows operating system, the task manager or task mgr.exe is one method of

obtaining process information.

you'll manage mobile apps that are running

on the OS

You can send this signal to a running process with the

CTRL+C key combination.

You can search for a process easily in Process Explorer by either pressing

Control F, or clicking on the little binocular button.

You can send a sigint signal through the keyboard combination (Linux)

Ctrl + C Example in the sudo parted shell you can use Ctrl+C and it will terminate the parted shell back to BASH

You can also send the SIGTSTP signal using the keyboard combination, (Linux)

Ctrl + z

From a PowerShell prompt, you can use a Commandlet called what to get all the running processes.

Get-Process

Kill Process Tree

In Process Explorer it'll kill the process and all of its descendants. So, any child process started from it will be stopped.

Kill Process

In Process Explorer kills the process

Suspended

Instead of killing a process, you can use this option to suspend it and potentially continue it at a later time.

Restart

It will stop and start the process again. it will be restarted as a child of the procexp.exe process. This is the process name for Process Explorer.

What do the different column mean when you run the ps -x command? (Linux)

PID is the process ID TTY, this is the terminal associated with the process, STAT this is the process status, if you see an R here it means the process is running or it's waiting to run. T for stopped, meaning a process that's been suspended. S for interruptible sleep, meaning the task is waiting for an event to complete before it resumes. TIME, this is the total CPU time that the process has taken up. command, this is the name of the command we're running.

To resume the execution of the process, you can use the (Linux)

SIGCONT for continued signal. ex: kill -CONT 1082

One of the most common signals you'll come across is called

SIGINT, which stands for signal interrupt.

ps command (Linux)

The command used to obtain information about processes currently running on the system. ex: ps -x

SIGKILL (Linux)

This will kill your process with a lot of metaphorical fire. The signal does its best to make sure the process get absolutely terminated without giving it time to clean up.

What does the ps -ef command show? (Linux)

UID is the user ID of the person who launched the process. PID is the process ID, PPID is the parent ID 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. CMD or command is the name of the command that we're running.

Once you start up your Browser, the operating system takes that resting code then turns it into

a running, responding, working application.

From the command prompt, you can use utility called TaskList to show

all the running processes.

From the app switcher, I can see a list of

apps running on this iPhone.

When a mobile app is running, there will be one or more processes

associated with them, but those details will be managed by the OS.

on the home screen, all of the apps are

backgrounded and there are no foreground apps.

From the iOS app switcher, we can swipe up on any of the background apps, this will

close the app

You can open Task Manager with the

control shift escape key combination or by locating it using the start menu.

You can think of processes as

programs in motion

In Linux, there are lots of signals that we can send the processes. These signals are labeled with names starting with

sig

SIGTSTP (Linux)

signal for terminal stop, which will put your process in a suspended state. ex: kill -TSTP 10754

To view the files that correspond to processes we can look into (Linux)

slash proc directory. ex: ls -l /proc There are a lot of directories here for every process that's running.

You can generate a signal with

special characters on your keyboard and through other processes and software.

If we right-click, suspend the process, we'll see that in the CPU column, the process explorer output, the word

suspended appears. While a process is suspended, it doesn't consume the resources it did when it was active. We can kick it off again by right-clicking and selecting the Resume option.

The kill command without any flags sends a (Linux)

termination signal or SIGTERM. This will kill the process, but it'll give it some time to clean up the resources it was using. Ex: kill 10835 The kill command with the PID number

What happens to the background apps when you are using a foreground app

the OS will suspend background mobile apps. The OS can occasionally wake a backgrounded app to allow to do some work, but it will try to keep apps suspended as much as it can.

While in task manager, you can click on the details menu option and here, you can see a whole bunch of other information you can get the task manager to display, including

the PID number

When you are using a foreground app all of these other apps are in

the background

The task manager tells you what application or image the process is running along with

the user who launched it and the CPU or memory resources it's using.

Process Explorer can be helpful to find out..

which processes use a certain file, or if you want to get insight into exactly what the process is doing, and how it works.

The app switcher shows you the apps in order from

most recently used to least recently used.

If you see something that says notepad.exe.mui (example) MUI stands for

multilingual user interface, and it contains a package of features to support different languages.

You can use sigint in Linux to...

interrupted process and the default action of this signal is to terminate the process that's interrupting.

Process Explorer

is a utility Microsoft created let IT support specialists, systems administrators, and other users look at running processes.

Signal

is a way to tell a process that something's just happened.

Each new app that you open will be kept

kept backgrounded and usually suspended. This helps the device use less battery power

In Linux we can terminate a process using the

kill command