To use your system, you’ll have to know how to create, move, rename,
and delete files and directories. This section describes how to do
so with the standard Debian commands.
The best way to learn is to try things. As long as you aren’t root
(and haven’t yet created any important personal files), you cannot
mess up too seriously. Jump in—type each of these commands at the
prompt and press Enter.
pwd
One directory is always considered the _current working directory_
for the shell you’re using. You can view this directory with the pwd
command, which stands for Print Working Directory. pwd prints the
name of the directory you’re working in—probably /home/yourname.
ls
ls stands for “list,” as in “list files.” When you type ls, the
system displays a list of all the files in your current working
directory. If you’ve just installed Debian, your home directory may
well be empty. If your working directory is empty, ls produces no
output, because there are no files to list.
cd /
cd means “change directory.” In this case, you’ve asked to change to
the root directory.
pwd
This verifies that you’re working in the root directory.
ls
Lets you see what’s in /.
cd
Typing cd with no arguments selects your home directory— /home/
yourname —as the current working directory. Try pwd to verify this.
Before continuing, you should know that there are actually two
different kinds of filenames. Some of them begin with /, the root
directory, such as
/etc/profile. These are called _absolute_ filenames because they
/refer
to the same file no matter what your current directory is. The other
kind of filename is _relative_.
Two directory names are used _only_ in relative filenames: . and ...
The directory . refers to the current directory, and .. is the
parent directory. These are “shortcut” directories. They exist in
_every_ directory. Even the root directory has a parent
directory—it’s its own parent!
So filenames that include . or .. are _relative_, because their
meaning depends on the current directory. If I’m in /usr/bin and
type ../etc, I’m referring to /usr/etc. If I’m in /var and type
../etc, I’m referring to /etc. Note that a filename without the root
directory at the front implicitly has ./ at the front. So you can
type local/bin, or ./local/bin and it means the same thing.
A final handy tip: The tilde ~ is equivalent to your home directory.
So typing cd ~ is the same as typing cd with no arguments. Also, you
can type things like cd ~/practice/mysubdirectory to change to the
directory
/home/yourname/practice/mysubdirectory. In a similar way, ~myuser is
equivalent to the home directory of the user “myuser,” which is
probably something like /home/myuser; so ~myuser/docs/debian.ps is
equivalent to
/home/myuser/doc/debian.ps.
/
/
/
Here are some more file commands to try out, now that you know about
relative filenames. cd to your home directory before you begin.
mkdir practice
In your home directory, make a directory called practice. You’ll use
this directory to try out some other commands. You might type ls to
verify that your new directory exists.
cd practice
Changes the directory to practice.
mkdir mysubdirectory
Creates a subdirectory of practice.
cp /etc/profile .
cp is short for “copy.” /etc/profile is just a random file on your
system, don’t worry about what it is for now. We’ve copied it to .
(recall that . just means “the directory I’m in now,” or the current
working directory). So this creates a copy of /etc/profile and puts
it in your practice directory. Try typing ls to verify that there’s
indeed a file called profile in your working directory, alongside
the new mysubdirectory.
more profile
This lets you view the contents of the file profile. more is used to
view the contents of text files. It’s called more because it shows
one screenful of the file at a time, and you press the space bar to
see more. more will exit when you get to the end of the file, or
when you press q (quit).
more /etc/profile
Verifies that the original looks just like the copy you made.
mv profile mysubdirectory
mv stands for “move.” You’ve moved the file profile from the current
directory into the subdirectory you created earlier.
ls
Verifies that profile is no longer in the current directory.
ls mysubdirectory
Verifies that profile has moved to mysubdirectory.
cd mysubdirectory
Changes to the subdirectory.
mv profile myprofile
Note that unlike some operating systems, there is no difference
between moving a file and renaming it. Thus there’s no separate
rename command. Note that the second argument to mv can be a
directory to move the file or directory into, or it can be a new
filename. cp works the same way.
As usual, you can type ls to see the result of mv.
mv myprofile ..
Just as . means “the directory I’m in now,” .. means “parent of the
current directory,” in this case the practice directory you created
earlier. Use ls to verify that that’s where myprofile is now.
cd ..
Changes directories to the parent directory—in this case practice,
where you just put myprofile.
rm myprofile
rm means “remove,” so this deletes myprofile. Be careful! Deleting a
file on a GNU/Linux system is _permanent_—there is no undelete. If
you rm it, it’s _gone, forever_. Be careful! To repeat, deleting a
file on a GNU/Linux system is _permanent_—there is no undelete. If
you rm it, it’s _gone, forever_.
rmdir mysubdirectory
rmdir is just like rm, only it’s for directories. Notice that rmdir
only works on empty directories. If the directory contains files,
you must delete those files first, or alternatively you can use rm
-r in place of rmdir.
cd ..
This moves out of the current directory, and into its parent
directory. Now you can type the following:
rmdir practice
This will delete the last remnants of your practice session.
So now you know how to create, copy, move, rename, and delete files
and directories. You also learned some shortcuts, like typing simply
cd to jump to your home directory, and how . and .. refer to the
current directory and its parent, respectively. You should also
remember the concept of the _root directory_, or /, and the alias ~
for your home directory.