Chmod Calculator

How to Use This Calculator

1. Check or uncheck permissions for Owner (read, write, execute).
2. Check or uncheck permissions for Group (read, write, execute).
3. Check or uncheck permissions for Others (read, write, execute).
4. The calculator displays the chmod value and the command to use.

Chmod Permission System

Chmod uses a 3-digit number system:

Example: 755 means owner has 7 (all permissions), group has 5 (read+execute), others have 5 (read+execute). This is common for executable files.

Full Description

Chmod (change mode) is a Unix/Linux command that sets file and directory permissions. The permission system controls who can read, write, and execute files, providing security and access control. Chmod uses a 3-digit number where each digit represents permissions for one category: owner (file owner), group (users in the file's group), and others (everyone else).

Each permission type has a numeric value: Read = 4, Write = 2, Execute = 1. These values are added together to create combined permissions. For example, 7 = 4+2+1 (read+write+execute), 6 = 4+2 (read+write), 5 = 4+1 (read+execute). The three digits represent owner, group, and others in that order. Common values include 755 (executable files), 644 (regular files), and 600 (private files).

This calculator helps you determine chmod values by selecting permissions. Check or uncheck permissions for owner, group, and others, and it calculates the chmod number and shows the command. Use it to understand file permissions, set appropriate access levels, or learn the chmod system. Proper file permissions are essential for system security and access control.

Frequently Asked Questions