Week 2

Synopsis: Chapter 2 Linux Directory Structure

This first section is a synopsis of the chapter using the headings and subheadings from the textbook, with descriptions in my own words.

• Common Top-Level Directories
• 
  
• / The Root Directory
• Everything else is located below the root directory.
• Full access to root is usually restricted, especially on multi-user systems like servers.
• /bin Binaries
• Programs are stored in the directory for binaries, since they normally are in that format to run.
• The directory /usr/bin is home to user installed binaries.
• A convention that I am aware of is that normally, binaries need to be placed in a directory named bin to run, although it usually can be any directory named bin.
• /etc System Configuration Files
• The Et Cetera directory is used to store system configuration files, such as screen resolution, other X Window System settings, and network settings, to name a few..
• /home Home Directories
• The Home directory is a user’s primary directory to use.  The user’s own files are kept here.
• /opt Optional or Third-Party Software
• Most user-installed programs are located here, such as Spotify or Chrome.
• /tmp Temporary Space
• Files that are only needed temporarily are normally stored in a temporary space directory, such as caches and compressed software downloads.
• /usr User-Related Data, Read-Only
• This is where user installed software and its documentation is located.
• /var Variable Data
• Logs and such are normally stored in variable data directories.
• Application Directory Structures
• There isn’t much I can say about this, other than that the paths typically are either usr/local/applicationName or opt/applicationName.  Also, sometimes libraries or logs used by a program are located in places like /var/opt/applicationName as well.
• Organizational Directory Structures
• Sometimes directories are named after teams or organizations, such as /MCC or /Romanov.

Questions and Observations

I am not sure what is the practical difference, besides the name and location, between usr/local and usr/bin.  Is it that usr/bin contains only binaries while usr/local can contain other types of files as well?  I’m also unsure as to what the practical difference between usr/local and /opt, .  It’s worth noting that the file system root is not exactly analogous to C:/ on Windows, because other drives are not mounted below C:/ on Windows, rather they have their own drive letters.  On GNU/Linux and UNIX systems, root is the directory that is at the root of the directory tree, hence the name root.  

Here is a link (https://youtu.be/vjMZssWMweA) to an interesting Documentary about GNU/Linux.