Red Hat Enterprise Linux 5 Administration Unleashed

CHAPTER 4Understanding LinuxConceptsSo far, this book has covered installing Red Hat EnterpriseLinux and post-installation essentials. Before continuing, itis important to establish a firm background in a few basicUNIX and Linux topics such as navigating the desktop,knowing how the filesystem is structured, being able to usethe command line, and understanding file permissions. Ifyou are already familiar with this information, skimthrough it quickly as a review and continue. If you are newto a UNIX-based operating system, this chapter can serve asan overview of Linux concepts.IN THIS CHAPTER. Learning the Desktop. Filesystem Hierarchy System. Shell Basics. Becoming the Root User. Manual Pages. Editing Text Files. File Permissions. Initialization Scripts. RunlevelsLearning the DesktopUnless you customized the installation and only installedthe programs absolutely necessary for the system to functionin its desired capacity, you most likely installed thesoftware necessary to use the graphical desktop environment.If so, after the system boots, the graphical loginscreen appears as discussed in Chapter 2, “Post-InstallationConfiguration.”As you can see, it consists of the actual desktop area, a fewicons on the desktop, and two panels. The top panelcontains the menus, icons to common desktop applicationssuch as a web browser, the system time, and a volumecontrol icon.The menus on the top panel are divided into three categories:. Applications: Contains the majority of the programmenu items, which are also divided into categoriessuch as Internet and System Tools to make it easier tofind the program you need.