Ubuntu Directory Structure + Some Commands

this topic has to be the first topic in this blog but it was not. what i will show in this topic is the hierarchy of the ubuntu also all linux since they all have same hierarchy since it is a standard from FHS. Here is the file system structure with a brief explanation:



Navigating Through the File System

Now how about navigating through the file system in terminal. Use the cd command to navigate through the Ubuntu file system. This command is generally used with a specific directory location or pathname, like this:

$ cd /etc/apt/

Under Ubuntu, the cd command can also be used with several shortcuts. For example, to quickly move up to the parent (higher-level) directory, use the cd command like this:

$ cd ..

To return to one's home directory from anywhere in the Linux file system, use the cd command like this:

$ cd

You can also use the $HOME shell environment variable to accomplish the same thing. Type this command and press Enter to return to your home directory:

$ cd $HOME

You can accomplish the same thing by using the tilde (~) like this:

$ cd ~

Don't forget the pwd command to remind you where you are within the file system!

Another important command to use is the ls command, which lists the contents of the current directory. It's commonly used by itself, but a number of options (or switches) available for ls give you more information. For instance, the following command returns a listing of all the files and directories within the current directory, including any hidden files (denoted by a . prefix) as well as a full listing, so it will include details such as the permissions, owner and group, size and last modified time and date:

$ ls -al

You can also issue the command

$ ls -R

which scans and lists all the contents of the sub-directories of the current directory. This might be a lot of information, so you may want to redirect the output to a text file so you can browse through it at your leisure by using the following:

$ ls -alR > listing.txt

TIP
The previous command sends the output of ls -alR to a file called listing.txt, and demonstrates part of the power of the Linux command line. At the command line you are able to use files as inputs to commands, or generate files as outputs as shown. In later posts we will consider that matter.