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Chmod 040

Owner has no permissions. Group can read. Others have no permissions.

Numeric Notation

040

Symbolic Notation

---r-----

Command

chmod 040 file

Permission Breakdown

Detailed view of permissions for each user category

Owner

✗ Read✗ Write✗ Execute

Group

✓ Read✗ Write✗ Execute

Others

✗ Read✗ Write✗ Execute

For Files

chmod 040 filename.txt

Changes permissions of a single file

chmod 040 *.txt

Changes permissions of all .txt files

After applying chmod 040, files will display as:

---r----- filename.txt

For Directories

chmod 040 dirname

Changes permissions of a directory

chmod -R 040 dirname

Recursively changes all files and subdirectories

After applying chmod 040, directories will display as:

d---r----- dirname

Common Use Cases for Chmod 040

Shared Reading

Files that need to be readable by multiple users or groups.

Restricted Access

Files with restricted access, not available to public users.

General Purpose

This permission set is useful when you need access.

Related Chmod Codes

Explore similar permission configurations

Try the Interactive Calculator

Experiment with different permission combinations

Understanding Chmod 040

The chmod 040 command sets specific file permissions in Linux and Unix systems. This permission configuration owner has no permissions. group can read. others have no permissions.

In the numeric notation 040, each digit represents the permission level for different user categories. The symbolic representation ---r----- provides a visual way to understand these permissions, where 'r' means read, 'w' means write, 'x' means execute, and '-' means no permission.

When you execute chmod 040 filename, you're modifying the file's access control list to match this specific permission pattern. This is essential for maintaining proper security and access control in multi-user environments.