Task path / input to outcome
How to calculate chmod permissions
- 01
Enter the permission value
Use 3–4 octal digits, or explicit u/g/o/a clauses with one +, - or = per clause. Separate clauses with commas. X adds execute only for a directory or when an execute bit is already set at that step. A single u/g/o operand copies that class, for example g=u.
- 02
Start symbolic clauses from the right base
Symbolic clauses start from these permissions (default 644) and apply from left to right. Octal input sets the complete mask and ignores this context. This is a preview of one target; no file is inspected.
- 03
Add a path and choose recursion
Type the target path so the generated command includes it, quoted for a POSIX shell. Turn Apply recursively on only when you mean the whole directory tree: it adds -R, and chmod -R can change thousands of files with one paste. Review the path twice — there is no undo in a terminal.
- 04
Calculate and read the summary
The summary shows the resulting class bits and any special flags. s/S show setuid or setgid; t/T show sticky. Uppercase means execute is absent. Numeric commands use five octal digits so unrequested directory special bits are cleared too; symbolic commands keep your expression and apply it against each real target's own permissions. Ownership, ACLs, and filesystem rules can still affect the outcome on the actual machine.
- 05
Copy the command
Copy result puts the exact command — numeric or symbolic, with the quoted path — on the clipboard for a terminal or a deployment script. Nothing runs here: the calculator only builds the string, so paste it where you intend and check the target path one last time before pressing Enter.