9 Mar
2017
9 Mar
'17
12:25 p.m.
I was trying to look at mini-unix so I mounted the disk image inside
unix v6 via:
/etc/mount /dev/rk4 /usr/mini-unix
and I noticed that if I ran the mount command as a user and not root
that /etc/mtab would not be updated (but it was updated as expected as
root). Of course /etc/mtab is owned by root :)
Then I noticed something else when I did an ls in the /usr directory:
drwxrwxrwx 20 31 368 Sep 3 1976 mini-unix
Normally I would see things like:
drwxrwxr-x 2 bin 48 May 13 1975 adm
What does the 31 mean?
Mark
9 Mar
9 Mar
12:32 p.m.
The 31 is likely a UID number not found in /etc/passwd
Insofar as I know, you can set the ownership of a file to any arbitrary integer within the
range of the uid_t (or whatever it was in ye olden days). See chown(8).
Erik
9:01 p.m.
When you mount the disk, the mount point displays the inode information of
the root directory of the mounted disk.
As Warren points out, that directory is owned by user id 31, but your
machine has no passwd file entry for that uid.
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3 comments
4 participants
participants (4)
-
Erik E. Fair -
Mark Longridge -
Ron Natalie -
Warren Toomey