chmod 555 — what r-xr-xr-x means

When to use 555

Executables or directories that should run for all users but never be modified — useful for hardening system binaries or a directory whose contents must stay fixed.

Set it with chmod

Apply this permission to a file:

chmod 555 filename

Or apply it recursively to a directory and everything inside it:

chmod -R 555 directory/

Other common permissions

• chmod 777 rwxrwxrwx
• chmod 755 rwxr-xr-x
• chmod 644 rw-r--r--
• chmod 700 rwx------
• chmod 600 rw-------
• chmod 640 rw-r-----

Or build any permission with the interactive chmod calculator.