[TUHS] Who's behind the UNIX filesystem permission

Arthur Krewat krewat at kilonet.net
Sat Aug 3 01:17:31 AEST 2019



On 8/2/2019 10:35 AM, Noel Chiappa wrote:
>      > From: Arthur Krewat
>
>      > there's the setuid bit on directories - otherwise known as the sticky
>      > bit.
>
> Minor nit; in V6 at least (not sure about later), the 'sticky' bit was a
> separate bit from SUID and SGID. (When set on a pure/split object file, it
> told the OS to retain the text image on the swap device even when no active
> process was using it. Hence the name...)
>

Ah yes, I remember that now... sorry.

Sticky bit is the low-order bit on the first octet which is usually left 
off and assumed to be zero. So to set it, it would be 1755. 4755 would 
be setuid. Woops.

art k.



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