Unix and Linux: Visual QuickStart Guide, Fourth Edition

Chapter 5. Controlling Ownership and Permissions

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• Understanding file ownership and permissions

• Finding out who owns what

• Finding out which group you’re in

• Changing the group association of files and directories

• Changing ownership of files and directories

• Changing permissions

• Translating mnemonic permissions to numeric permissions

• Changing permission defaults

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Unix and Unix-like operating systems are multiuser systems in which your files are separate from Jane’s files, which are separate from Joe’s files, and so on. Any file you create is separate from other users’ files and usually cannot be directly accessed by Jane, Joe, or any other user.

Occasionally, though, you will need to share files. For example, ...