chmod
See how the permission bits move
Developer
Result
Enter the current mode and a mode to apply.
How to use
Enter the current state
Provide the current mode and choose a regular file or directory.
Enter a chmod mode
Enter a numeric or symbolic mode. Check umask when user classes are omitted.
Inspect changed bits
Review octal and symbolic forms, each class, special bits, and the change made by each operation.
Frequently asked questions
- How does X differ from x?
- x always affects execute/search. X applies only to a directory or to a file where at least one execute bit is already set.
- Are +w and a+w the same when users are omitted?
- No. +w leaves bits protected by umask untouched, while a+w explicitly ignores umask.
- Does this change a real file?
- No. It calculates only the mode bits entered in this browser.