Objectives
Upon completion of this unit, you should be able to:
1) Log into a Red Hat Enterprise Linux system
2) Start X from a console
3) Access the command line from X
4) Change your password
5) Understand the nature of root privileges
6) Elevate your privileges
7) Edit plain text files
Logging into a Linux System
1) Two types of login screen: virtual console (text-based) and graphical logins (called display managers)
2) Login using login name and password
3) Each user has a home directory for personal file storage
Switching between virtual consoles and the graphical environment
1) A typical Linux system will run six virtual consoles and .e graphical console
- Server systems often have .ly virtual consoles
- Desktop and workstation typically have both
2) Switch among virtual consoles by typing: Ctrl+Alt+F[1-6]
3) Access the graphical console by typing: Ctrl+Alt+F7
Element of the X Window System
1) The X Windows System is Linux’s graphical subsystem
2) Xorg is the particular version of the X Window System used by Red Hat
- Open source implementation of X
3) Look and behavior largely controlled by the desktop environment
4) Tow desktop environments provided by Red Hat:
- GNOME: the default desktop environment
- KDE: an alternate desktop environment
Starting the X server
1) . some systems, the X server starts automatically at boot time
2) Otherwise, if systems come up in virtual console, users must start the X server maually
- The X server must be pre-configured by the system administrator
- Log into a virtual console and run startx
- The X server appears . Ctrl+Alt+F7
Changing your password
1) Passwords control access the system
- Change the password the first time you log in
- Change it regularly thereafter
- Select a password that is hard to guess
2) To change your password using GNOME, navigate to System->Preference->About Me and then click password
3) To change your password from a terminal: passwd
The root user
1) The root user: a special administrative account
- Also called the superuser
- root has near complete control over the system (… and a nearly unlimited capacity to damage it!)
2) Do not login as root unless necessary
- Normal (unprivileged) users’ potential to do damage is more limited
Changing Identities
1) su – creates new shell as root
2) sudo command runs command as root
- Requires prior configuration by a system-administrator
3) id shows information . the current user
Editing text files
1) The nano editor
- Easy to learn, easy to use
- Not as feature-packed as some advanced editors
2) Other editors:
- gedit, a simple graphical editor
- vim, an advanced, full feature editor
- gvim, a graphical version of the vim editor
End of Unit2
1) Questions and answers
2) Summary
- Login name and password
- startx
- gnome-terminal
- passwd
- su
- nano
