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Hey guys and welcome back. In the previous nugget we had talked about some of the configuration

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files that we could use to ultimately display user notifications. What we're now going to

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do is to see what those files actually look like. So what I'm going to do here is I'm

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going to go to my terminal and I will open up the first file which would be the Etsy

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issue file. In fact I'll do this with super user privileges and I'll type in my password.

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So now we see this configuration file we actually see Ubuntu, we see the version long term supports

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and we see these special characters backslash n backslash l. Now we talked about these special

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characters and these are ultimately going to represent different values. Now what I can

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do here is I can actually modify this particular file. So what I'll do is I'll just say hello

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there please login and again let's maybe change this value from backslash n maybe we'll say

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backslash r and we'll also do backslash t for the time. Okay so if I just write this out

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and I escape what I want to do is I want to get my login screen. Now remember this is

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going to be a pre login we're not going to see after login and crucially this is not

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going to be seen over the network. So I open up my putty session let's open this up notice

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that we don't actually see this pre login message here we just have our login prompts

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let me close this down. What I will do here is I will actually change the run level to

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run level 3 which will just be a command line interface this will now restart the system

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and look at this we actually see the exact message that we changed within that configuration

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file we see that hello there we also see the time so on so forth now we can login so I'll

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say ipv0 type in my password hit enter and now that I've logged in we see the post login

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message so what I will do is I'll just change the run level back to run level 5 so hit enter

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type in my password and we'll get our graphical user interface back there we go let's just

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log back in but like I say we didn't actually see this pre login banner over ssh so what

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we're going to do is we're going to make a modification to that ssh configuration file

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remember we talked about that so I'll say sudo nano ssh ssh d underscore config and hit

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enter type in the password now what I'm going to do is I'm going to scroll all the way down

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till I see my banner right here I'm going to uncomment this and I'm going to change

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the value none and I'm going to now specify that the banner should look in sssh.net so

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now my ssh configuration is now pointing to this particular file what I'm now going to

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do is I'm going to modify this file so I'll say issue.net and what I will do I'll just

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delete this and say welcome to CBT Nuggets system please login okay so let's just save

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you and I'll escape and now what I'm going to have to do to make this actually operational

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is I'm going to have to restart my ssh config so what we'll say is sudo system CTL restart

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ssh d this will reload that configuration file so now what I'll do is I'll go to login

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via ssh I'll get my putty session let's open this up now when I type in my login username

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as ipv0 we actually see this pre authentication banner you see that right here even though

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I've not actually logged in so what I will do is I'll type in my password right now and

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if I hit enter now we actually log into the system so before we logged in we get this

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message right here and after we authenticate we get the post message so if we want to modify

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what we see after the login like I say we can modify the etsemotd banner or the etsemotd

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configuration file so what I'll do is I'll say sudo nano etsemotd and I'll just say congrats

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on logging in have a great day at work there we go so let's save this and what I will do

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put up putty okay let's login with my password hit enter notice now what we actually see here

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we can see indeed we have our message of the day congrats on logging in have a great day

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at work now these are ultimately automated messages they are generated when someone logs

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in automatically from these configuration files however if we just want to send a message

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to everyone on the system what we can do is use the wall command so what I could see here

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is a wall and then I could broadcast backing up the system tomorrow please do local backups

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now if I hit enter this is just going to display this message right here but the key thing to note

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here is this is actually a broadcast message now as it transpires I only have the user ipv0 on the

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system but if you imagine there were 10 different users all logged on to the system this message

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here using the wall command is going to be broadcast to absolutely everyone so this is a good way to

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send messages to the entire user base when you have to communicate something on the fly and like

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I say it tells you who the message came from and it will be displayed to all different users so as

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we can see here we have these different configuration files that we can use to ultimately send

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particular messages either pre-login or post-login as well as messages for local logins as well as

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messages for remote logins such as over SSH and we also have the wall command to allow us to send

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messages to all users on the system on the fly as we see fit okay doc so that is us for understanding

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user notifications I hope this has been informative for you and I'd like to thank you for viewing