rwxrwxrwx - Read, write, and execute for everyone (Dangerous)

Executable - Make file executable

Ownership - Change file owner and group

Default - Set default permissions (755/644)

Developer Reference

Linux Permissions

Q: 755

rwxr-xr-x - Owner has all; others can read and execute (Common for scripts)

Q: 644

rw-r--r-- - Owner can read/write; others can only read (Common for files)

Q: 600

rw------- - Owner can read/write; no access for others (Private keys)

Visual guide to chmod numbers (777, 644) and permission symbols.

Understanding Linux file permissions is crucial for server security. This reference defines read (r), write (w), and execute (x) permissions and their octal equivalents.

Numeric

Read, write, and execute for everyone (Dangerous)

rwxrwxrwx

Owner has all; others can read and execute (Common for scripts)

rwxr-xr-x

Owner can read/write; others can only read (Common for files)

rw-r--r--

Owner can read/write; no access for others (Private keys)

rw-------

Command

Make file executable

Executable

Change file owner and group

Ownership

Basics

Read permission

Write permission

Execute permission

Advanced

Set default permissions (755/644)

Default

Sudo

Root

Tricks

Run last command with sudo

Re-run

Attributes

Make file immutable (cannot be changed/deleted)

Immutable

List file attributes

List Attr

ACL

Get Access Control Lists

ACL

Set specific user permissions

ACL

Never guess 'chmod 777' again. Use this guide to set secure permissions for files, directories, and scripts.