Unlike most personal computers, which have fundamentally closed file systems, IRIX is founded on a multi-user, network model, so it is an open file system. Basically, this means that if you are using your system on a shared network, it may be like having a very nice house that needs locks and keys. If you don't exercise the security measures outlined below, your files are open to other people on your network.

Note that you may not need to know much about system security and permissions if:

• Your system does not share a network with other systems, and no one else uses your system.
• Your system security is set up and managed by a company system administrator.

However, if the above exceptions do not apply to you, read on.

Creating User Account Security

As you learned when you read Login (User) Names and Accounts, you have your own user account on your system and your login name is the door that gets you into it. To put a lock on that door, you can add a password. If you are particularly concerned with keeping your files private, you should also put a password on your root account, because it is possible to access your personal user account through the root account, even if the user account has a password. The System Manager includes interactive guides that step you through creating passwords and other tasks. To use it, choose System > System Manager from the Toolchest, and click "Security and Access Control."

Preventing Others From Viewing or Copying a File You Own

By default, even if you have passwords on your user and root accounts, your system assumes the following about files that you own (the files in your home directory):

• You want other users to be able view or copy the contents of these files.
• You don't want other users to make changes to the files.

You can change this so that other users are unable to view or copy the file. This security feature is called the "permissions" settings. To change the permissions on files or directories, use the System Manager. From the Toolchest, choose System > System Manager, and click "Security and Access Control." The System Manager includes interactive guides that step you through changing permissions.