Chapter 27. Console Access

Chapter 27. Console Access

27.1. Disabling Shutdown Via Ctrl-Alt-Del
27.2. Disabling Console Program Access
27.3. Defining the Console
27.4. Making Files Accessible From the Console
27.5. Enabling Console Access for Other Applications
27.6. The floppy Group

When normal (non-root) users log into a computer locally, they are given two types of special permissions:

  1. They can run certain programs that they would otherwise be unable to run.

  2. They can access certain files (normally special device files used to access diskettes, CD-ROMs, and so on) that they would otherwise be unable to access.

Since there are multiple consoles on a single computer and multiple users can be logged into the computer locally at the same time, one of the users has to essentially win the race to access the files. The first user to log in at the console owns those files. Once the first user logs out, the next user who logs in owns the files.

In contrast, every user who logs in at the console is allowed to run programs that accomplish tasks normally restricted to the root user. If X is running, these actions can be included as menu items in a graphical user interface. As shipped, these console-accessible programs include halt, poweroff, and reboot.

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