The filesystem is comprised of directories and files. Here, we'll see how to make them.
To start, change to the Desktop directory:
$ cd ~/Desktop
/home/mpiper/Desktop
Note that by using the tilde ~,
we'll get to the Desktop from wherever we are in the filesystem.
Next,
use the mkdir command to make a new directory:
$ mkdir new
$ ls
data-shell data-shell.zip new
Change to the new directory and get a listing:
$ cd new
$ ls
The new directory is empty.
The touch command can be used to make a new, empty, file.
$ touch haiku
$ ls -l
total 0
-rw-r--r--. 1 mpiper csdms 0 Jul 29 14:23 haiku
The l option to ls forces long output,
which shows, among other things, that the file haiku has zero bytes.
Let's add some content to this file. We'll do so with a text editor, an application that allows us to write in the file. Note that a text editor is different than a word processor (like Microsoft Word) which automatically applies markup and formatting to the text.
There are many different text editors available;
e.g., vi, emacs, atom, sublime,
but the one we'll use here is called nano.
It trades functionality for simplicity.
Open the file haiku with nano:
$ nano haiku
The nano editor has a simple interface.
Just type text.
I'll enter the following:
Yesterday it worked
Today it is not working
Software is like that.
(Funny, but computers are deterministic. If something's not working, it's likely because I did something wrong.)
Once you've entered the text,
hit the Ctrl-x key combination to save the file and exit.
Let's make a copy of our haiku:
$ cp haiku haiku-1
$ ls
haiku haiku-1
The cp makes a duplicate of a file.
The mv command moves a file from one location to another.
Let's move haiku-1 up to the Desktop directory:
$ mv haiku-1 ~/Desktop
$ ls
haiku
$ ls ~/Desktop/
data-shell data-shell.zip haiku-1 new
Note that haiku-1 has been moved from the new directory to Desktop.
The mv command can also be used to rename a file.
$ mv ../haiku-1 haiku.copy
$ ls
haiku haiku.copy
Here, we moved the file back to the new directory and renamed it.
Files can be deleted with the rm command.
Remove our haiku copy with
$ rm haiku.copy
$ ls
haiku
There is no concept of a "trash" or "recycle" bin in the shell. Once a file is removed, it's gone, irrevocably.
As a last step, let's move our haiku up to the parent directory, change to the parent directory, then delete the new directory:
$ mv haiku ..
$ cd ..
$ rmdir new
$ ls
data-shell data-shell.zip haiku
As rm removes files,
the rmdir command removes directories.
However, the directory must be empty before it can be removed.
The table below summarizes the commands and keyboard shortcuts described in this section.
| Command/Shortcut | Description |
|---|---|
| mkdir | creates a directory |
| touch | creates an empty file |
| nano | text editor |
| cp | copies a file |
| mv | moves or renames a file |
| rm | deletes a file (permanently) |
| rmdir | deletes a directory (permanently) |
| Ctrl-a | place cursor at start of line |
| Ctrl-e | place cursor at end of line |
| Ctrl-k | clear text to end of line |
| Ctrl-l | clear text in terminal |
Introduction to the shell | Previous: Files and directories | Next: Pipes and filters