chmod Tutorial

This tutorial is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License.

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This is a tutorial that teaches the UNIX ®/Linux ® chmod command. It presumes that you already know how to use the ls command to list the contents of a directory. The tutorial has been tested with Mozilla version 1.8 under Linux.

What is chmod?

chmod is a Unix command that lets you tell the system how much (or little) access it should permit to a file.

Here are all the topics:

• Changing File Permissions
• Your Permissions
• Group Permissions
• Others’ Permissions
• The chmod command
• chmod Examples
• Try chmod
• chmod Shortcuts
• Copying Permissions
• Try chmod again
• A Problem Solved
• A New Problem
• Setting User ID
• Quick Reference Summary
• chmod by the Numbers
• Numeric Mode in Action

You may download this tutorial as a gzipped tar file.

UNIX is a registered trademark of The Open Group.
Linux is a registered trademark of Linus Torvalds.