CLH-007

Permissions & Access Control

< Script House
operator@shadow:~
[SYSTEM] Access control module loaded
[SECURITY] Permission management enabled
> Mission: Master file permissions and access control
Type help for available commands.
operator@shadow:~$

CURRENT OBJECTIVE

ACCESS CONTROL BRIEFING

Understanding Permissions

Linux uses a three-tier permission system: Read (r), Write (w), Execute (x)

Each file has permissions for: Owner, Group, Others

Permission Values

SymbolOctalMeaning
r4Read
w2Write
x1Execute

Example: 755 = rwxr-xr-x

chmod - Change Mode

$ chmod 755 script.sh
Make executable by all
$ chmod 600 secret.txt
Owner only: read+write
SECURITY ALERT:

Never use chmod 777 on sensitive files!

PRO TIP:

Use stat filename for detailed info.