permissions repair on Macs

September 25, 2013 3:30 PM

What do messages such as the following mean: Permissions differ on “Applications​/iTunes.app/Contents/​Resources/zh_TW.lproj/​UniversalAccess.nib”; should be drwxr-xr-x ; they are -rwxr-xr-x . I know that the "drwxr-xr-x" and "-rwxr-xr-x" has some meaning in Unix, and I know OS X is based on Unix, but other than that, I don't really understand what I'm looking at. Anyone have any ideas?
posted by dfriedman to Computers & Internet (8 answers total)

Best answer: d=directory
r=readable
w=writable
x=executable

- means it is missing that permission bit

there are 3 sets of rwx, first is the file owner, second is the group's permission, and 3rd group is everyone's permission.
sometimes there is an extra bit at the end, or an 's' in the rwx section that i don't understand fully.

if its missing the 'd', then its a file not a directory, and something has gone very wrong, you cant just change permissions to fix that. The other permissions you can just change at the command line if you have appropriate permissions. if you don't own them you may have to become root to change them.
chmod u+rwx filename adds rwx for the user who owns it.
chmod g-rwx filename removes rwx for the group
chmod o+r filename adds read for everyone else.
posted by TheAdamist at 3:36 PM on September 25, 2013 [2 favorites]

Best answer: Those are permissions settings (that is, who can read, write, and execute a file). The only difference is the first character, d for directory vs - for file.

It's saying that file should be a directory, not a file. Which is a weird thing to say.
posted by zug at 3:36 PM on September 25, 2013

Best answer: See: https://discussions.apple.com/thread/5323141?start=0&tstart=0

Looks like this is a known issue.
posted by zug at 3:37 PM on September 25, 2013

Best answer: Those bizarre strings show (in a particularly unix-y way) who has permissions to Read, Write or eXecute a particular file - the file owner, other users who share the same group ID as the owner, and everyone else, like so:

OWNER-GROUP-WORLD

A file that can be read, written and executed by only the owner would look like this:

rwx------

Likewise, a file that can be read/written to/executed by the owner, but only read by everyone else, would look like this:

rwx--r--r--

In the example you show above:

drwxr-xr-x

...indicates a directory ("d") that can be read, written and executed by the owner but only read/executed by everyone else. You will also see "s" show up sometimes; these are files that set the user ID to something else when they're running (effectively changing the privilege of the program while it runs). More information on Unix file permissions can be found here.
posted by jquinby at 3:38 PM on September 25, 2013 [2 favorites]

Response by poster: OK, thanks. Will wait for the inevitable itunes 11.2...
posted by dfriedman at 3:39 PM on September 25, 2013

Yep, it's a confirmed and known bug with iTunes 11.1. The upside is that those permission errors will do NOTHING to damage your Mac OS X installation and will not slow your computer down at all. They're completely safe to ignore. Just use your Macintosh as you always do, and when iTunes 11.2 comes out, it should nip the permissions issue in the bud.
posted by dubious_dude at 1:21 AM on September 26, 2013

As others have commented, it is a configuration problem. Permissions repair appears to have been informed that the .nib files are directories. Clearly anything which uses the .nib files has no problems so just ignore it for now.
posted by epo at 4:13 AM on September 26, 2013

that "extra s" is the stickybit/setid/setgid bits.

(If you don't know what it is or how to use it, don't play with it..)
posted by k5.user at 8:41 AM on September 26, 2013 [1 favorite]