I recommend these commands to anyone who is
getting started with Linux.
1. Print working
directory (pwd)
The pwd command prints your
working directory. In other words, it outputs the path of the directory you are
currently working in. There are two options: --logical to display
your location with any symlinks and --physical to display your
location after resolving any symlinks.
2. Make directory
(mkdir)
Making
directories is easy with the mkdir command. The
following command creates a directory called test unless test already exists:
$
mkdir test
You
can make directories within directories:
$
mkdir -p test/one/two
If
directories test and one already exist, only
directory two is
created. If none of them exist, then three nested directories are created.
3. List (ls)
Coming
from MS-DOS, I was used to listing files with the dir command. I don't
recall working on Linux at the time, although today, dir is in the GNU Core
Utilities package. Most people use the ls command to display the files, along with all their
properties, are in a directory. The ls command has many options, including -l to view a long
listing of files, displaying the file owner and permissions.
4. Change directory
(cd)
It
is often necessary to change directories. That's the cd command's function.
For instance, this test takes you from your home directory into the Downloads directory:
$ cd Downloads
You
can quickly change to your home directory with cd ~ or just cd on most systems. You
can use cd .. to
move up a level.
5.
Remove a file (rm)
Removing
files is inherently dangerous. Traditionally, the Linux terminal has no Trash
or Bin like the desktop does, so many terminal users have the bad habit of
permanently removing data they believe they no longer need. There's no
"un-remove" command, though, so this habit can be problematic should
you accidentally delete a directory containing important data.
A
Linux system provides rm and shred for data removal. To
delete file read.txt,
type the following:
$ rm read.txt
However,
it's much safer to install a trash command, such as trashy or trash-cli. Then you can send files to a staging
area before deleting them forever:
$
trash read.txt
6. Copy a file (cp)
Copy
files with the cp command.
The syntax is copy from-here to-there. Here's an test:
$ cp test1.txt
newtest1.txt
You
can copy entire directories, too:
$ cp
-r dir1 newdirectory
7. Move and rename a
file (mv)
Renaming
and moving a file is functionally the same process. When you move a file, you
take a file from one directory and put it into a new one. When renaming a file,
you take a file from one directory and put it back into the same directory or a
different directory, but with a new name. Either way, you use the mv command:
$ mv test1.txt
file_test1.txt
8. Create an empty
file (touch)
Easily
create an empty file with the touch command:
$
touch one.txt
$
touch two.txt
$
touch three.md
9. Change
permissions (chmod)
Change
the permissions of a file with the chmod command. One of the
most common uses of chmod is
making a file executable:
$
chmod +x myfile
This
test is how you give a file permission to be executed as a command. This is
particularly handy for scripts. Try this simple exercise:
$ echo 'echo Hello $USER' > hello.sh
$
chmod +x hello.sh
$
./hello.sh
Hello,
TOM
10. Escalate
privileges (sudo)
While
administering your system, it may be necessary to act as the super user (also
called root). This is where the sudo (or super
user do) command comes in. Assuming you're trying to do something that your
computer alerts you that only an administrator (or root) user can do, just
preface it with the command sudo:
$
touch /etc/os-release && echo "Success"
touch:
cannot touch '/etc/os-release': Permission denied
$
sudo touch /etc/os-release && echo "Success"
Success
11. Shut down
(poweroff)
The poweroff command does
exactly what it sounds like: it powers your computer down. It requires sudo to succeed.
There
are actually many ways to shut down your computer and some variations on the
process. For instance, the shutdown command allows you
to power down your computer after an arbitrary amount of time, such as 60
seconds:
$
sudo shutdown -h 60
Or
immediately:
$
sudo shutdown -h now
You
can also restart your computer with sudo shutdown -r now or just reboot.
12. Read the manual
(man)
The man command could be the
most important command of all. It gets you to the documentation for each of the
commands on your Linux system. For instance, to read more about mkdir:
$ man
mkdir
