Chmod 333 Explained

Chmod 333: write and execute for everyone, no read. A rare permission for drop-box style directories where users can deposit files.

Permission

333

-wx-wx-wx

chmod 333 filename

Permission Breakdown

RoleRead (4)Write (2)Execute (1)OctalMeaning
Owner-wx3write, execute
Group-wx3write, execute
Others-wx3write, execute

Visual Permission Grid

Read
Write
Execute
Owner
-
w
e
Group
-
w
e
Others
-
w
e

Detailed Explanation

The permission 333 grants write and execute to everyone but denies read access to all.

Octal breakdown:

  • 3 (Owner): write (2) + execute (1) = write and execute
  • 3 (Group): write (2) + execute (1) = write and execute
  • 3 (Others): write (2) + execute (1) = write and execute

In symbolic notation this is -wx-wx-wx. Everyone can write to the file and execute it, but nobody can read its contents. For directories, users can create files and traverse into the directory but cannot list its contents.

This is a very unusual permission. Its primary use case is a "dropbox" or "submission" directory: users can deposit files into the directory but cannot see what other users have submitted. The execute bit allows directory traversal, and the write bit allows file creation, but the missing read bit prevents listing the directory contents. This pattern is sometimes used in educational settings for homework submission.

Use Case

Used for file drop-box directories in educational environments, where students can submit files but cannot see or copy other students' submissions.

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