This third hour focuses on the Unix hierarchical file system. You learn how the system is organized, how it differs from the Macintosh and Windows hierarchical file systems, the difference between relative and absolute filenames, and the mysterious . and .. directories. You also learn about the env, pwd, and cd commands and the HOME and PATH environment variables.
Goals for This Hour
In this hour, you will learn
- What a hierarchical file system is all about
- How the Unix file system is organized
- How Mac and PC file systems differ from Unix
- The difference between relative and absolute filenames
- About hidden files in Unix
- About the special directories . and ..
- About the env command
- About user environment variables, PATH and HOME
- How to find where you are with pwd
- How to move to another location with cd
The preceding hour introduced many Unix commands, but this hour takes a more theoretical approach, focusing on the Unix file system, how it’s organized, and how you can navigate it. This hour focuses on the environment that tags along with you as you move about, particularly the HOME and PATH variables. After that is explained, you learn about the env command as an easy way to show environment variables, and you learn the pwd and cd pair of commands for moving about directly.