Unix permissions calculator
Convert between the permission checkboxes, octal (755), and symbolic (rwxr-xr-x) modes — with setuid, setgid, sticky, umask, ls -l parsing, and ready-to-run chmod commands.
Added
How to use it
Calculator
Tick the boxes, type an octal mode (644, 4755), or type a symbolic one (rwxr-x---, or a
full ls -l column such as drwxrwxrwt) — every view updates. Apply chmod expression
runs a real chmod clause against the current mode: u+x, go-w, a=r, g=u, +t, a+X.
The tool explains what the mode allows — the meaning of r, w, and x differs between files and
directories — warns about risky combinations (world-writable without sticky, setuid scripts),
and writes both numeric and symbolic chmod commands for your path. Tick Recursive for
find-based commands that give directories and files different modes.
umask
Enter a umask to see the permissions new files (requested as 666) and directories (777) actually get.
Read ls -l
Paste ls -l or ls -la output (GNU or macOS) to get each entry’s octal mode, type, owner,
size, ACL or extended-attribute marker, and any warnings.
Sharing
Share link copies a URL that opens this tool exactly as you have it. Hand-written links work too: Calculator ?mode=750&dir=1&path=deploy&r=1, umask ?umask=027, ls -l ?ls=…. For example ?mode=2775&dir=1&path=shared.
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