IT 1100 : Introduction to Operating Systems
Viewing the Directory Tree
There are 2 commands we will learn for viewing our directory tree.
The first one is the
ls command. We know that using this command will display the directories and files in our current directory. But we can also see down into the directories within our current directory using the -R option. Yes it is a capital R.
ls -R /var/log
The second way is with the
tree command. Simply calling the command without options or arguments will display the directory tree for our current directory and all of its children in a beautiful easy to read format.
If we include an argument the
tree command will display the directory tree of the directory we provide
tree command does not come pre-installed on Linux. So it is not available on some Linux installations. It is installed for your use on scratch.
Printing to the screen
Sometimes we want to say simply Repeat after me.
To do this we use the
echo command. To print to the screen
Hello World. It looks like this:
echo "Hello World"
The quotation marks are optional - but useful for avoiding errors. Try the command and see that it does exactly what you would think. It echoes whatever text you give it.
Later in the course, we will see some fun uses for the command.
Just for fun - try
echo $HOME and see what it does.
To create files we are going to use the
touch command. Creating files is not its primary purpose, but it is a handy side effect of the command.
This command requires only an argument. Usage looks like this; where myfile.txt is the name of the file you want to create:
myfile.txt will be created in our current working directory
Saving your work on Scratch
How do I save my work on Scratch? is a question that gets asked every semester.
On your Windows or Mac computer (in your GUI) when you create a file or directory - do you have to do anything more than click the button that says: Add new Folder or Save file and then give it a name?
Linux works the same way - when you give the command to make a directory or create a file. Viola! It’s created. You don’t have to do anything more. You can exit and when you log back in all of your work is still there. And if we had a GUI interface you could see all the pretty icons too.
Open up a terminal connection to scratch and then Read and Complete the Excercises in the Book
Last Updated 12/15/2017