Set SUID with octal and watch the case change

Answer

chmod 4755 pwtool ls -l pwtool chmod u-x pwtool ls -l pwtool

`-rwsr-xr-x` becomes `-rwSr-xr-x`. The SUID bit never changed — the capital letter is reporting that owner-execute is now clear.

Sarwar & Koretsky 3e §5.6