How to create symbolic links in Ubuntu 12.04 shell

Usage: ln -s <target> <link>

target = existing file or folder you wish to create a symbolic link of.
link = the new file/folder link to be created

For example, to create a link to /var/www/html/wordpress in my home folder:

Or:

Output:

 

How to check your hard drive space in Ubuntu 12.04 shell

Type the following command from your shell prompt:

Output:
The device mounted on / is the root folder of your file system.

If you want to see the file system types as well:

Output:

Give root privileges to a new user & safely disable the root account on Ubuntu 12.04

Log into your server as root.

Create a new user account for yourself.

You’ll be prompted to choose a password and enter user information:

Now let’s give the new user “james” root/sudo permissions. Type ‘visudo’ to edit the /etc/sudoers file:

Find the lines that look like this:

And add your new user underneath, following the same pattern as root:

Save the file:

Press Control-X
Press the letter Y
Hit enter.

Now log out as root, and log in with your new account.

Finally, disable the root account using the ‘sudo’ command:

Output:
Now any time you need to run something using root permissions, just prefix those commands with “sudo” using your new user/account:

For example:

You’ll be prompted to enter your password if you haven’t used sudo for a few minutes prior, after which the command will run:

Enjoy!

How to check running tasks, CPU & RAM usage in Ubuntu 12.04

Check CPU Usage

Type “top” to see a multitude of information, constantly updated:

Output:

Hit the “1” key to see CPU usage by core:

And “q” to exit out:

To see a static list of the top 20 CPU-hogging tasks running on your system:

Output:

Or to list all tasks with both CPU & RAM usage:

For information about your CPU:

Output:

 

Check Memory (RAM) Usage

Type the following into your into your shell:

The output will look as follows:

In my case, I’ve got a total of 4GB of RAM and an 8GB swap file.

How to list users, add users, edit users and more in Ubuntu 12.04

To list all users you can use:

[Read more…]