Symbolic Notation
-r--r--r--(as shown by ls -l)-r--r--r--
typeownergroupother
Permission Matrix
| Read(4) | Write(2) | Execute(1) | Octal | |
|---|---|---|---|---|
| Owner | r | - | - | 4 |
| Group | r | - | - | 4 |
| Other | r | - | - | 4 |
What Does chmod 444 Mean?
Owner can read. Group can read. Others can read.
$ chmod 444 filenameCommon Use Cases
Read-only for everyone. Used for published reference files that should not be modified.
Security Notes
Write-protected but any user can read. Do not use for sensitive data — anyone on the system can view the contents.
Interactive Tool
Need to calculate a custom permission? Use the interactive permissions calculator to toggle individual bits and get instant results.
Unix Permissions Calculator