2.1 User Accounts
2.1.4 Logging in and out of the system
Logging in Using the CDE Login Screen
The CDE login screen replaces the usual login prompt common in UNIX systems. The login screen is the entry point into the system. If you do not have a login ID (or username) and password, you will not be able to access the system. Your user name for the interactive media activities will be user2. 

You must enter your login name into the appropriate boxed area, then press the Return key or left click on the OK button. If you log in incorrectly, you must repeat the procedure of entering your login name and password.

Note: If you make a mistake when entering either your login name or your password, you will be required to reenter both pieces of information. You can press the Ctrl + u (control key and a lower case letter u for undo) to clear the screen or you can left click on the Start Over button to return to the login display. 

The Start Over button will completely refresh the screen and remove any typed entry. Once you have logged in to the CDE Graphical Desktop, you will be presented with the Front Panel, which is your primary desktop management tool.

Exiting from CDE
Logging out prevents unauthorized users from gaining access to your files. You should log out anytime you will be away from your system for an extended period of time. To leave the CDE Session and log out of the UNIX system, click on the EXIT button on the front panel. Always be sure to exit before you shut down the system. By default, you will be asked to confirm that you want to log out. Confirmation is done by clicking on the OK button or by pressing Return when the OK button is highlighted. The current CDE session will be saved automatically so that you can return to the same workspace windows at your next CDE session. However, any data contained in the current set of open windows will be lost. You must therefore save all data before exiting from your CDE session. It is possible to change the default activities of the EXIT button so that confirmation is not required. This is discussed in a later chapter. Upon exiting the system you will return to the CDE Login Manager. 

Logging In Using the Command Line
As an alternative to logging in with the CDE login screen, you can bypass the CDE graphical desktop and go directly to the command line. To login from the command line, you will display the Options pull-down menu and select Command Line Login. You will need to press Return fairly quickly or the Login Manager will restart. 

Note - Your user name for the interactive media activities will be user2. For the hands-on labs, you will be assigned a user name by the instructor which should be in the form of user99 where user is lower case and 99 represents a number such as 1, 2, etc.

You will enter your user name at the console login and then your password at the password prompt. 

Note: Your password does not appear as you type it. By default, if you do not have a password, you are automatically prompted for one during the initial login.

Command line login is quick since the CDE graphical desktop is not loaded. Use this option to do file management or troubleshooting from a shell prompt.

Exiting From the Command Line
To log out while at the command prompt, you will simply type exit and press enter. This will exit you from the system and redisplay the console login prompt. If you do not log back in again within 30 seconds, the CDE Login Manager screen will be displayed again. Use the accompanying media activity to practice logging in and out as user1 using the command line.

Proper UNIX System Shutdown
UNIX systems are designed to be left running continuously and are normally shut down by an administrator (root account password is required). An administrator will shut the system down to install a new release of the operating system, add hardware or perform routine system maintenance.

If you must power off a UNIX system, it is very important to shut down correctly. This is the case with most operating systems and allows all system changes recorded in RAM to be written to disk and an orderly shutdown of processes and file systems. It is similar to clicking Start/Shutdown with Windows 9x or logging out with NT/2000. Failure to do so can result in File corruption.

Using the init and shutdown commands are the primary ways to shut down a UNIX system.

  1. Become superuser.
  2. Shut down the system by using either the init 0 (init <space> zero> or the shutdown command.
  3. Power off at the "type any key to continue" prompt (Intel PC) or the "ok" prompt (Sun workstation).
Interactive Media Activity (Flash, 20 kB)
  Logging In and Out with the CDE Login Screen

Work through the media activity in Figure to practice logging in and out of a UNIX system using the login screen.

 

Interactive Media Activity (Flash, 20 kB)
  Logging In and Out from the Command Line

Work through the media activity in Figure to practice logging in and out from a UNIX system command line environment.