Linux Permissions & Users Cheat Sheet (Printable PDF)

Before you fix it with 777.

Use it when: you can't tell why a process can't read a file, when you're deciding between chmod and chown, when a fresh user can do nothing at all.

On the sheet: chmod, chown, umask, users, groups and sudo — the permission model behind every "permission denied".

Not on it: ACLs and SELinux.

Format: 3-page US Letter PDF, dark terminal theme, print-ready. Instant download, no account needed.