Making files and folders in Git & Command Line

So far you've looked at files that were already there. Now you'll make your own. In the terminal you make folders and files with a few short commands, and write text into files without opening any program.

These commands print nothing when they work. That's normal: no news is good news. Use ls to check what you made.

Making a folder

mkdir, short for "make directory", makes a new folder with the name you give it:

The new travel folder sits next to the others. If a folder with that name is already there, mkdir says so and changes nothing:

Folders inside folders

mkdir makes one folder, inside a folder that already exists. Ask for a folder two levels down, and it stops, because the folder in the middle isn't there yet:

The -p option makes every missing folder on the way, in one go:

-p never complains when a folder already exists, which makes it a safe choice.

Empty files

touch makes an empty file. You can name several files at once:

Both files are 0 bytes, because nothing is in them yet. If a file already exists, touch leaves what's inside alone.

Writing text into a file

echo prints text on the screen. Add > and a file name, and the text goes into that file instead. The quotes keep the text together, and you'll learn more about them later.

cat shows what's inside a file. You'll meet it properly in the next topic:

> makes the file if it isn't there. If it is, > replaces everything in it:

The sunscreen line is gone. There's no warning and no undo, so take care with >.

Several lines at once

To write a few lines, use cat > file <<EOF. It reads every line you type next and puts them in the file, until you type a line that says EOF. The terminal shows > at the start of each line while it waits:

EOF stands for "end of file". It isn't written into the file: it only marks where your text stops.

Naming files

The part of a name after the last dot is its extension. It hints at what kind of file it is: .txt for plain text, .html for a web page, .jpg for a photo.

The extension is only part of the name. map.jpg is still an empty file, not a picture, until something puts a photo in it.

Good file names are short and lowercase, with dashes or underscores instead of spaces, like road-trip.txt or road_trip.txt.