Book Image

Learn Linux Quickly

By : Ahmed AlKabary
Book Image

Learn Linux Quickly

By: Ahmed AlKabary

Overview of this book

Linux is one of the most sought-after skills in the IT industry, with jobs involving Linux being increasingly in demand. Linux is by far the most popular operating system deployed in both public and private clouds; it is the processing power behind the majority of IoT and embedded devices. Do you use a mobile device that runs on Android? Even Android is a Linux distribution. This Linux book is a practical guide that lets you explore the power of the Linux command-line interface. Starting with the history of Linux, you'll quickly progress to the Linux filesystem hierarchy and learn a variety of basic Linux commands. You'll then understand how to make use of the extensive Linux documentation and help tools. The book shows you how to manage users and groups and takes you through the process of installing and managing software on Linux systems. As you advance, you'll discover how you can interact with Linux processes and troubleshoot network problems before learning the art of writing bash scripts and automating administrative tasks with Cron jobs. In addition to this, you'll get to create your own Linux commands and analyze various disk management techniques. By the end of this book, you'll have gained the Linux skills required to become an efficient Linux system administrator and be able to manage and work productively on Linux systems.
Table of Contents (24 chapters)

Removing an alias

Let's create another temporary alias named lastline that will display the last line in a file:

elliot@ubuntu-linux:~$ alias lastline="tail -n 1"

Now let's try our new alias on the /home/elliot/.bashrc file:

elliot@ubuntu-linux:~$ lastline /home/elliot/.bashrc 
alias date="date;cal"

Alright! It works well. Now, if you wish to delete the alias, then you can run the unalias command followed by the alias name:

elliot@ubuntu-linux:~$ unalias lastline

So now the lastline alias has been deleted:

elliot@ubuntu-linux:~$ lastline /home/elliot/.bashrc 
lastline: command not found

You can also use the unalias command to temporarily deactivate a permanent alias. For example, if you run the following command:

elliot@ubuntu-linux:~$ unalias memory

Now, the permanent alias memory will not work in the current Terminal session:

elliot@ubuntu-linux:~$ memory

Command 'memory' not found, did you mean:
command 'lmemory' from deb lmemory
Try...