Working with Permissions

Permissions determine how users can access resources on a system.  System security is configured by the user’s UID (User ID), his GIDs (Group ID), (both primary and secondary), and the permissions on the object she is attempting to access.

Permission Trio Bits

The figure below shows the 10 positions (1 type bit and 3 trios of permission bits) that make up the permissions section of a file.

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