- Installing Linux Step by Step
- Linux Tips for Beginners
- Beginners guide to Reading and Finding Files in Linux
- Using Grep to Search for Text in Linux
- Understanding Linux File Permissions
- How to Archive, Compress and Extract files in Linux
- Linux Piping and Redirection
- Linux Hardlinks and Softlinks
- How to Create and Use Bash Scripts
- Basic Data Recovery in Linux
- Apache Administration on Linux
- MySql Administration on Linux
- Switching from Windows to Linux
This is my collection of Linux tips beginners, which I am adding to as I learn more about using Linux. This page serves as my notepad and reminders for commands and is published online in the hopes it helps others starting out with Linux.
Creating a Symbolic Link
A symbolic link is a pointer to another file or directory, like a shortcut in Windows. Unlike shortcuts however, the symbolic link can be used just like the original file or directory. Symbolic links are very good if you need to have multiple copies of the same file in different locations.
You can use the command below to create a symbolic link to a file.
ln -s {/path/to/file-name} {link-name}
Example below will create a link to /home/timtrott/public_html and create a "false" folder called /www. When you change directory to /www, you will really be in /home/timtrott/public_html.
ln -s /home/timtrott/public_html/www /www
Creating Shell Scripts
A shell script is a Linux version of a MS-DOS batch file, only a bit more flexible and powerful. They can be created using any text editor. I'm going to create a sample shell script that will mount a network drive.
All shell scripts start with #!/bin/bash. The following lines are executed line by line.
#!/bin/bash sudo mount -t cifs //192.168.0.10/websites/www /usr/www
The script must have it's permissions changed to allow execute.
chmod +x scriptname
I like to keep my scripts in my home folder /home/tim/ That way I can call them using ~/scriptname.
See the article below for a more in-depth look at bash scripts.
Creating Multiple IP Addresses
I will be working on multiple websites at a time and as such, I need to allocate an IP address to each one. I can do this by using IP alias. This is done easily enough by adding some entries to /etc/network/interfaces.
sudo pico /etc/network/interfaces
And add the following block of code. Repeat as required.
auto eth0:0 iface eth0:0 inet static name Ethernet alias LAN card address 192.168.0.101 netmask 255.255.255.0 broadcast 192.168.0.255 network 192.168.0.0
Once complete you need to restart the network interfaces.
sudo /etc/init.d/networking restart
Host Tables
A host table is a simple text file that associates IP addresses with host names, one line per IP address. It isn't normally necessary to change this, however I have a situation in which I need to redirect a host name for my database server to my local host.
sudo pico /etc/hosts
The format for the file is ip_address hostname alias. My hosts file looks like this:
127.0.0.1 localhost 192.168.0.5 mydomain.com ubuntu 127.0.0.1 my.databaseserver1.com 127.0.0.1 my.databaseserver2.com # The following lines are desirable for IPv6 capable hosts ::1 localhost ip6-localhost ip6-loopback fe00::0 ip6-localnet ff00::0 ip6-mcastprefix ff02::1 ip6-allnodes ff02::2 ip6-allrouters
Modifications to this file normally take effect immediately, except in cases where the file is cached by applications.
Enable the Power Button
By default on my installations, the power button does not function, except to immediately power off. Instead I'd rather send a power down message to the OS so that my server can gracefully close and power off.
First we need to install the Advanced Configuration and Power Interface (ACPI) package
sudo apt-get install acpid
And edit the config file if required
sudo pico /etc/acpi/powerbtn.sh
When the power button is pressed, the system no goes down with a message stating the power button has been pressed.
/sbin/shutdown -h now "Power button pressed"
Linux Cheat Sheets
Here are a few very handy Cheat sheets for Linux which will introduce you to the basic commands.
Above all, the best way to learn Linux is to use it. Use it a lot.
Whenever you run into a problem with a command, do some online searching. Almost any time you run into a wall, you're going to find that a lot of people have run into it before you and a number of them will have written something about how they got over it.
This post is part of the series Introduction to Linux. Use the links below to advance to the next tutorial in the couse, or go back and see the previous in the tutorial series.