 Okay, this is a series that I'm starting on the Linux shell and shell scripts now I just want to go over exactly what the shell is well The shell is basically an interpreter when you write programs They're either normally going to be a compiled language such as C or C plus plus where you have a binary file that Kind of runs on its own. They need some library files and stuff Then you also have scripting files, which are just plain text their text files You basically create a list of commands and you run through an interpreter an interpreter It's just a program that reads that file line by line and does what it says and so the shell is basically an interpreter that you can Either dump a script file into or you can have a prompt where you can type stuff such as echo Hello And it will run those commands now I want to be clear that there are different shells different shell environments, and they're also Different they're built-in commands and there are external commands So for example, I just ran the echo command which is built into pretty much every shell for displaying information to the screen It is built in that shell So as long as you have a shell that that command will be there now There are external commands such as grep and said and ock These are commands programs that are normally on almost every system even if you're on a very lightweight system Some aspect of those tools are going to be available for you But they are not built into the shell so they may not be there And then there are you know External commands can be anything from nmap On up. I mean technically you can start stuff like firefox from the shell and That's not necessarily a shell program, but you can run it from the shell and running a text-based application is basically the same Concepts so I want to clarify that I'll try to in tutorials point out when a command is an external command And you have to make sure you have it installed rather than something that's built in now There's also different types of shells and I'll go over in the next video more of the differences like on my system I have my default shell set to Z shell and the way you can test some most systems one way is type in echo Dollar sign zero and that will tell you what shell you're running and you can see I'm running a Z shell on most Linux systems and macOS and Probably some other operating systems as well Bash is the default shell. So I just typed in bash and now I am in the bash shell and again I'll go over more of the differences between bash and Z shell in the next video So be sure to check check out the playlist in the description of this video to get the full playlist of all the videos in this series and So they some of the Z shell commands and bash internal commands will work different where something external like grip It doesn't matter whether I'm in Z shell or or bash on the system I'm running the same instance of grip where a command like the read command or the LS command might actually work Different depending on what shell you're in The way you can tell what shells are installed on your system. You can cat out a file so cat Ford slash ETC Ford slash shells so here we're going to display the information from a file called shells It's just a text file Inside our ETC folder within our root directory of our file system So I can display that and well it should list out all valid log in shells that are available on my system SH is available here But on most cases that's going to point to your default shell which will normally be bash on many systems As I said, I have Z shell installed But then you can also see that I have dash installed our bash and then also screen and Tmux Which are a little different and I might get to those in future videos. I've done videos on them in the past as well But just want you to be aware that there are different shells in most cases on my Videos, I'm using a Z shell But when I write out scripts, I usually write them in bash since that's commonly installed on most people systems Where Z shell may not so again, this is part of series in the next video. I will go over a few of the differences and reasons that I use Z shell over bash and then we'll get into actually writing scripts and So forth and so on in future videos be sure to check out the link in the description of this video for the full play list I hope you enjoyed this video Hope you're excited about the series again The first few weeks is going to be a whole bunch of videos going over some of the basic stuff that a lot of stuff that many of you May know I'm going to try to point out some issues might have with simple commands like the echo command some things that you Might come across that you're you're not sure why it's not working But so just a little more in-depth on the basic stuff and then I'm going to go through requests from viewers and Try to show how to do many different things based on your request and a long list of tutorials I want to do So I thank you for watching again. Please visit filmsbychrist.com. That's Chris of the K There should be a link in the description be sure to like subscribe share and comment