Convert Unix file permission modes between the familiar symbolic form (rwxr-xr-x or u=rwx,g=rx,o=r) and the three-digit octal form used by chmod (755, 644).
How it works
Each triad encodes read (4), write (2), and execute (1) bits for owner, group, and others. Symbolic nine-character strings map each position to r, w, x, or -. Assignment strings like u=rwx,g=rx,o=r set those bit groups explicitly. Octal input accepts three digits, or four digits where only the last three permission digits are used (a leading sticky/setuid digit is ignored for this calculator).
When to use it
- Translate a directory listing mode into the
chmodargument you will run - Explain a numeric mode from a Dockerfile or Ansible task as rwx letters
- Double-check that
644really means owner read/write and group/other read-only
Limitations
Special bits (setuid, setgid, sticky) are not modeled in the symbolic nine-character output. ACLs, SELinux labels, and Windows ACLs are out of scope. Invalid characters or wrong triad lengths fail with invalid-mode.
Example
Input rwxr-xr-x with direction symbolic→octal yields symbolic rwxr-xr-x and octal 755. Input 644 with octal→symbolic yields rw-r--r-- and 644.