Your desktop file manager is a powerful and important tool for managing files and directories using the graphical desktop. This chapter discusses various shell prompt commands that can be used to manage files and directories on your Red Hat Enterprise Linux system. This chapter also discusses compression tools to create archives of your files for backup or to conveniently send to others.
Due to system security, unless you are root, you are not allowed to gain access to all system-level files and directories. If you do not have the permission to open, delete, or execute a file, an error message is displayed showing your access has been denied. This is normal behavior and is used to prevent non-privileged users from modifying or deleting important system files.
Every operating system has a method of storing data in files and directories so that it can keep track of additions, modifications, and other changes.
In Linux, every file is stored in a directory. Directories can also contain directories; these subdirectories can also contain files and other subdirectories.
You might think of the file system as a tree-like structure and directories as branches. These directories may contain, or be the "parent" of, directories within it (called subdirectories) which hold files and may contain subdirectories of their own.
There would not be a tree without a root, and the same is true for the Linux file system. No matter how far away the directories branch, everything is connected to the root directory, which is represented as a single forward slash (/).
Red Hat Enterprise Linux uses the term root in several different ways, which might be confusing to new users. There is the root account (the superuser, who has permission to do anything), the root account's home directory (/root) and the root directory for the entire file system (/). When you are speaking to someone and using the term root, be sure to know which root is being discussed.
Unless you are a system administrator or have root (superuser) access, you probably do not have permission to write to the files and directories outside of your home directory. Certain directories are reserved for specific purposes. For example, /home/ is the default location for users' home directories.
Users that do not have superuser access might find the following directories useful for finding their home directories, reading documentation, or storing temporary files.
/home/ — Default location for users' home directories. For example, a user with the username foo has the home directory /home/foo/.
/usr/share/doc/ — Location of documentation for installed packages. For example, the documentation for the redhat-config-date software package is located in the directory /usr/share/doc/redhat-config-date-<version-number>/.
/tmp/ — The reserved directory for all users to store temporary files. Files stored here are not permanent. A system process removes old files from this directory on a periodic basis. Do not write any files or directories that you want to keep permanently here.
Your Red Hat Enterprise Linux system is compatible with many other Linux distributions because of the Filesystem Hierarchy Standard (FHS). The FHS guidelines help to standardize the way system programs and files are stored on all Linux systems.
To learn more about the FHS, refer to the Red Hat Enterprise Linux Reference Guide. You can also visit the FHS website at http://www.pathname.com/fhs/.