Remove _unknown user from permissions

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Level 1

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Remove _unknown user from permissions

Hi All,

I believe my problem began when I changed my shortname (home folder name). I did it according to Apple's instructions ( http://support.apple.com/kb/HT1428) but everything didn't work out as it should have.

To make a very long story short, now I have a sprinkling of files and folders in my Macintosh HD (my home folder seems to be fine) that have the _unknown user in the permissions. I'm into music and some of the folders and files for a few 3rd party plug-ins for Logic Pro 9 have the _unknown user in the permissions. Logic crashes when I try to load any plug-in with _unknown user in the permissions. I was able to solve this problem one by one by manually changing the permissions of each plugin file with the bad permissions to give myself read/write privileges.

Is there is an (easy) way to completely nuke the _unknown user? I suspect that there are a ton of other files/folders in my system that have the same issue and I can't imagine having to manually do this one by one for each of them. HELLLLLP.

Thanks in advance,
BOSSDOGG

iMac 27" 3.06GHz Intel C2D, Mac OS X (10.6.3), 4GB DDR3

Posted on Apr 10, 2010 3:47 PM

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Answer 1

Barney-15E

Level 10

122,594 points

Apr 10, 2010 3:57 PM in response to BOSSDOGG

It is _unknown because it has a UID that doesn't match anyone on the computer.
What you need to do is find out what the default permissions and owner should be. I don't know what they would be for that program, so I can't tell you. Once you figure that out, you can use the terminal to change the owner and permissions with chown and chmod. If you want a GUI, use [BatChmod|http://www.macchampion.com/arbysoft/BatchMod/Welcome.html]. It works very well.

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Answer 2

BOSSDOGG Author

Level 1

0 points

Apr 10, 2010 4:22 PM in response to Barney-15E

Hi Barney,

Thanks for your fast reply. There were 7 plugins that had the permissions screwed up so that they would not load properly in Logic. All I had to do to fix the problem is to add the admin user and give it read/write privileges. Apparently, the problem is that for these files, no administrative user had permission to read/write the file. Prior to adding admin, the only users were _unknown (read/write) and everyone (no access). When I added admin with read/write it works fine.

In response to your question, I have no idea what the default permissions should be but it works when I add admin (read/write). I've done that for the 7 that I had a problem with. Moving forward, my concern is that there are tons of other files in my system that I'm unaware of that need similar treatment. Is there a quick (easy) way to do this? Wouldn't it be easier to just delete the _unknown user or to somehow change _unknown to me or admin?

Thanks,
BOSSDOGG

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Answer 3

Barney-15E

Level 10

122,594 points

Apr 10, 2010 6:10 PM in response to BOSSDOGG

Even if you delete the _unknown user, that won't change your problems. The Files' owner is set to a user ID (UID) that doesn't have a user associated with it or it has been set to 99, the uid of _unknown.

You can find all files that belong to a particular user with this Terminal command:

find ~/ -user _unknown

The ~/ tells it to search your home directory. Use just plain / if you want to search the entire hard drive.

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