Linux File Permissions - ArtTHEbard/SYS255FA19-Notes GitHub Wiki

Basic File Permissions

• Permissions are: Read, Write, eXecute.
• Permissions are displayed using ls -l, and are formatted [owner permissions][group permissions][other users permissions]
• Permissions can be granted by setting the owner (chown 'user' /filepath), then using the command (chmod [u,g,o][+-]/filepath
• The command ls -ld will list the owners and permissions for the directory.
• The command ls -l will list the permissions for the contents of a directory.

Permission Lab

• I first used the useradd command to create the Users: Alice, Fred, Bob.
• I used the groupadd -g 1010 marketing and groupadd -g 1011 management commands to create the management and marketing groups.
• I used the usermod command to modify the user files and add Bob and Fred to the marketing group, and Alice to the management group.
• I used the command (chrgrp [selected group][directory/file to change]) to assign group permissions to the directories and files, and used the command (chmod [u,g,o][+-][/filepath] to edit the permissions for the groups.
• Finally, to give the custom permissions to specific users, I used the chown command to assign ownership to the desired files, and the chmod command to assign the appropriate permissions.