New user account gid bug in Tiger

Question

Originally when I setup my system I did a migration from another computer to keep the uid/gid matching. My uid=xxxxx / gid=502. The gid did not have a name associated with it. When I
added my Father as a new account, he got uid=501 / gid=501 and both user and group were
named his accounts short name. Recently I added an account for a friend. Tiger added this person as uid=502 / gid=502 with both user and group getting the short name of the new account.
I think you can see the problem here. This new account is in the same group as me. Shouldn't
Mac OS X, when determining what uid/gid to give a new account give one that is unique?
To fix this I went into NetInfo Manager and changed the user and group to uid/gid = 503 and then
did a chown to change the ownership of all her files under /User/... Are there other places
which need changing?

Answer 1

vrh wrote:
Originally when I setup my system I did a migration from another computer to keep the uid/gid matching. My uid=xxxxx / gid=502. The gid did not have a name associated with it.
This is odd.
You could try the net info application to create a new group.
I think that this command will create a new group.
Macintosh-HD -> Applications -> Utilities -> Terminal
sudo nicl -raw /var/db/netinfo/local.nidb -create /groups/mygroup gid 601
http://discussions.apple.com/thread.jspa?threadID=121786&tstart=0
When I added my Father as a new account, he got uid=501 / gid=501 and both user and group were named his accounts short name. Recently I added an account for a friend. Tiger added this person as uid=502 / gid=502 with both user and group getting the short name of the new account.
I think you can see the problem here. This new account is in the same group as me. Shouldn't Mac OS X, when determining what uid/gid to give a new account give one that is unique?
To fix this I went into NetInfo Manager and changed the user and group to uid/gid = 503 and then did a chown to change the ownership of all her files under /User/...
What? Why would you pick 503? Pick something like 600.
It looks Mac OS has started its group ID accounting from 501. Next, It picked 502. It looks like to me the next number that will pick will be 503.
Are there other places
which need changing?
This is tricky stuff.
I suggest that you make a complete backup of your system. You should create a second administrator account from which you use to change your original account. You should log out your original account before proceeding.
You need to change these things:
1) Your account information
2) All of your files & folders
Each file has an owning user and a group of users that are allowed to access the file. Also, there is a another access for all users. The owning user is the UID field. The group of users is the GID.
1) Use theNetInfo Manager to change what uid and gid are defined for your account application. ( This doesn't change the UID & GID on your files and folders! ) { not in 10.5 }
harddrive -> Applications -> Utilities -> NetInfo Manager
In the middle column is the function. Pick users then select your user. Click on the lock at the bottom of the panel. Go into the property list and change UID and GID."
2)
Macintosh-HD -> Applications -> Utilities -> Terminal
sudo find -x / -user 501 -exec chown 5464 {} \;
sudo find -x / -group 20 -exec chgrp 211 {} \;
#combined change of uid & gid
sudo find -x / -user 501 -exec chown 5464:211 {} \;
There are two schemes for assigning a group to a user:
1) Assign all users to a common group like staff. Used in Mac OS 10.2 & 10.5
2) Assign each user to their own group. A user like test would be in group test. Used in Mac OS 10.4.
You should not have multiple users assigned to the same uid. My worry is that if you are only change in the 50x range, you could run into a conflict.
Your best bet is to change to a high number like 5464 on all of your accounts.
On Mac OS, there are a few files that have the old uid as part of their names. The .Trashes file will be on your removal media and maybe everywhere.
/.Trashes/501
/Library/Caches/com.apple.IntlDataCache.501
/Library/Caches/com.apple.IntlDataCache.sbdl.501
/Library/Caches/com.apple.user501pictureCache.tiff