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Module 3~9 min

Understanding File Permissions

Linux controls who can read, write, or run each file through a permissions system. This lesson introduces the basics.

What You'll Learn

  • The three types of file permissions
  • Who permissions apply to
  • How to read a basic permissions listing

Read, Write, and Execute

Every file has three basic permissions: read (view its contents), write (modify it), and execute (run it as a program or script).

Owner, Group, and Others

Permissions are set separately for the file's owner, its group, and everyone else. This allows fine-grained control over exactly who can do what with a file.

Example

A script might be set so the owner can read, write, and run it, their group can only read and run it, and everyone else has no access at all.

Key Concepts

PermissionsOwnerExecute

Key Takeaways

  • The three basic permissions are read, write, and execute
  • Permissions are set separately for owner, group, and others
  • This system allows fine-grained control over file access

Knowledge Check

Which permission allows a file to be run as a program?

Which permission allows a file to be run as a program?