← Explorations
Linux Permissions
Read, write, execute. Make the octal click.
Permission grid
-rw-r--r-- alice staff notes.txt
r · 4
w · 2
x · 1
Owner
0
Group
0
Other
0
000
---------
$ chmod 000 notes.txt
User action simulator

Pick a user, pick what they want to do, and see if the permissions let them.

Who is trying?
What action?
Allowed
No permissions set yet.

Click any pattern to load it into the Sandbox.

Special permission bits (advanced)

4xxx
setuid — when set on an executable, the program runs as the file's owner instead of the user who ran it. Example: passwd runs as root so it can update /etc/shadow.
2xxx
setgid — on a directory, new files inherit the directory's group instead of the creator's. On an executable, runs as the file's group.
1xxx
sticky bit — on a directory, only the file's owner can delete files inside. Used on /tmp so users can't delete each other's temp files.

Windows is different

Windows NTFS uses Access Control Lists (ACLs) instead of rwx triples. Each file has a list of permissions per user or group: Read, Write, Read & Execute, Modify, Full Control. Permissions can be inherited from the parent folder. There's no octal — you set permissions in Properties → Security or with icacls.
Score: 0 / 0 (0%)
Streak: 0