Getting Started for the First Time in UNIX

In order to use SSC's UNIX system, you must be a registered user. Each user has a user id, a password, and an area of the file system reserved for storing his or her files. To become a user, you must fill out an application that can be obtained in McNeil 303. We will process this user application as quickly as possible (1-2 days). However, we handle a large number of requests so please be patient.

Logging In

When you login for the first time, you should log into ssdc.sas.upenn.edu. For every subsequent login, you must log into ssc.sas.upenn.edu. If you don't know how to get to a login prompt, see a consultant in GDAL.

At the login prompt, type your user id and hit enter.

		IBM AIX Version 3 for RISC System/6000 
		(C) Copyrights by IBM and by others 1982, 1991.
		Login: userid

The system will then request you to input your password; you will have been assigned a user password by the system administrator in order to facilitate logging onto the system for this first time; however, you should change your password the first time you log onto the system. You will not see your password on the screen as you type it, so type it carefully.

		password:********

It is important to create a password that is not easily guessed by computer programs. Common names, phone numbers, birthdates are not recommended; rather, a password that contains letters, punctuations marks and numbers is most secure. For example, two words separated by a punctuation mark is recommended: boy!girl.

For information about logging in from various computers and from home, there are other SSC documentation texts.

Changing Your Password

It is possible to change your password at any time by typing the command passwd. The system will respond with "changing password for 'user id.'" It will then prompt you for your old password, then your new password and finally ask you to input your new password again in order to confirm that it is correct.

Logging Out

To terminate your session and log out, type exit.

Your login session

After you have successfully logged in, you will receive a confirmation message. You may also see a message of the day. For example, instructions to users of specific software applications, etc. After such messages display, you will be logged on in your home directory which is your user id:

				ssdc /home/userid $

ssdc The host machine. SSDC is a IBM RISC 6000 model 340.
/home /userid The user's home directory.
$ The command prompt

At this point your interaction with UNIX is controlled by a program called a shell. To issue a command to the shell type the command followed by hitting enter. The shell will execute the command and then send the output to your terminal. For example:

ssdc /home/userid $ ls

[this command lists the files in the current directory]

Mail	mbox	  sasuser

[examples of possible files in home directory]

ssdc /home/userid $

[after the list prints to screen, the system returns you to the command line]

Frozen Terminal

If your terminal locks up or "freezes", you can try hitting ctrl q or ctrl /. Hold down the ctrl key and type the "q" or "/" key and then release both at the same time. On an Xterminal you can type ctrl alt backspace to reboot the terminal. For more information, see the X-terminals section of this manual.

Back to Unix help page