Getting Started

Let's get rolling

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The first thing you're going to need is a development environment, or a way to write and run your code. I prefer using the Terminal. It might have a bit of a learning curve, but that's why you're here - to learn!

I use the Terminal to navigate through my computer system. You can achieve the exact same results as dragging and dropping folders, creating new files, and moving stuff to the trash all by typing a few simple commands. Later on, I'll cover using the Terminal to create and edit files using Vim. But first, let's go over the basic tools you'll need to know to use the Command Line.

I'm going to assume that for this tutorial you will have the Terminal open and are following along as I describe some of the basic commands. Select which operating system you are using and I'll explain how to get set up and open Terminal.

Command Line Navigation

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cd

cd is used to change directories. Usually, you might double click on a folder to open it, but if you type cd folder-name, you will place yourself into that directory. You can also use tab to autocomplete 'folder-name' by simply pressing tab if you have typed the first few letters of the name. It's important to remember that cd is always in reference to the current active directory.

There are a handful of symbols that have special meanings. . means the current directory. .. means the parent directory. ~ means the home directory. And it is possible to string together a series of cd commands using / between directory names.

For example, cd example will change the active directory to 'example', as long as there is a directory called example within your current directory. But cd ~ will change the active directory to Home regardless of where you are. And by stringing together some commands like cd ~/Desktop/example you can change to the example directory within Desktop from anywhere.

ls

ls will simply list all of the items within the active directory.

mkdir

mkdir will create a new directory wherever you specify. The new directory will be named whatever you put after the command (and avoid naming it something with a space). So mkdir example will create a directory called example in the active directory, and mkdir ~/Desktop/example will create a new directory in Desktop (as long as Desktop already exists).

mv

mv can be used in two general ways. It can be used to move a file from one directory to another, and it can also be used to rename files. The first string given after mv will be the file or directory to rename or move, and the second string given will be the new name or the new location.

So mv old.txt new.txt will rename old.txt to new.txt. mv dir1 dir2 will rename the directory dir1 to dir2. But if dir2 already existed, the previous command would place dir1 inside of dir2. mv document.txt dir1 will move document.txt into the directory dir1.

And if you would like to move a directory full of other directories and files, change the command to be mv -r dir1 dir2, as long as dir2 already exists.

cp

cp is used in the exact same manner as mv, only it will copy a file from one location to another, and can rename the file in the process. So cp hello.txt dir/goodbye.txt will copy the file contents from hello.txt to inside of the dir directory and rename it to goodbye.txt. But if you want to just copy it to a new location without renaming it, you could use one of the special symbols mentioned before, such as cp hello.txt dir/. to just copy the file, including the name, into the dir directory.

rm

rm is used to delete files and directories. But be careful, because this will actually just delete files without an "are you sure" prompt or putting them into the trash to be cleared later. Use rm hello.txt to delete the hello.txt file. If you would like to remove a directory and all of its contents modify the command to be rm -r dir.

Vim

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Make sure to check out the Vim tutorial in the External Resources. But here's a quick (poorly done) explanation.

Vim is a program used for creating and editing files within Terminal. Simply entering vim file.txt into the Command Line will open a Vim session where you can create or edit file.txt. Vim is known as an IDE, and if you'd like to use another one like Emacs or Eclipse, that's fine - but I'm going to cover Vim because I think it's an incredibly useful tool.

Vim also has a bit of a learning curve and might seem a bit basic or lame at first, but it is very powerful and customizable. The first thing you might notice is that nothing you type will show up. There are a handful of different modes that you can enter while editing a document. When you first enter Vim, you are in visual mode which provides a handful of unique tools. If you would like to type anything, you must enter insert mode. To do this, simply hit i on the keyboard. To end any active mode, hit esc. The next thing you might notice is that you cannot use your cursor, you have to navigate with the arrow keys. And if you would like to save your new or updated file exit your active mode (esc) and type :w followed by enter. To quit Vim, exit the active mode as above and type :q followed by enter. The above commands can be combined to save and quit by entering :wq. After saving and quiting Vim file.txt will be a new file, or the existing file will have been updated.

If you'd like to customize your Vim editor, do a quick Google search for '.vimrc' to explore all of the options you have for personalizing Vim.

Review

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You should now have a good understand of what the following series of commands will accomplish.

cd ~/Desktop
ls
mkdir gatetest
ls
cd gatetest
vim test1.txt
vim test2.txt
ls
rm test1.txt
ls
cd ..
rm -r gatetest

But to review each line:

1. Changes your active directory to 'Desktop'
2. Lists the items within the 'Desktop' directory
3. Makes a new directory in 'Desktop' called gatetest
4. Lists the items within the 'Desktop' directory
5. Changes your active directory to 'gatetest'
6. Begins a Vim session for a file called test1.txt
7. Begins a Vim session for a file called test2.txt
8. Lists the items within the 'gatetest' directory
9. Deletes the test1.txt file
10. Lists the items within the 'gatetest' directory
11. Changes the directory to gatetest's parent directory (Desktop)
12. Deletes the gatetest directory and all of its content

Developing in the Shell

Overview