Introducing UNIX and Linux

The Computing Environment

Overview
What is a Computer?
Hardware
      Processors
      Input Devices
      Output Devices
Software
      Input and Characters
            Control Characters
      Application Programs
            Programming Languages
      The Operating System
      System Administration
History of UNIX and Linux
Conventions
Summary

System Administration

Traditionally, UNIX systems have been multi-user systems with individuals simply gaining access as users. In these situations, there is usually someone, somewhere, who is in day-to-day charge of the system, and known as the system administrator. If you are using this kind of system and have problems that neither you nor your colleagues are able to resolve, then the system administrator will either be able to help, or at least point you in the direction of someone who can. You should find out who your system administrator is, and make sure that you are in possession of any documents that he or she wishes users of the system to have.

More recently, however, there has been a move towards the use of UNIX for individually-run personal computers, especially with the recent success of Linux. If this is your situation, then it is you who will act as the system administrator for your machine, and will be responsible for its maintenance. In particular, if you are using Linux on your own personal computer, make sure you read the handbook supplied with the operating system in conjunction with this book. If there are any differences, it will be an invaluable help.

Finally, there is one user of the system who is called the super-user. He or she has special privileges on the system, and is allowed to perform certain actions forbidden to ordinary users, such as having the unrestricted right to change and to delete files on the system. The super-user may or may not be the same person as the system administrator.