Restoring lost group permissions on mac

Question

Using mac's terrible file sharing prefs, I managed to goof up permissions on my Documents directory. My non-Documents directories have permissions like this:

drwx------+ for .
drwxr-xr-x+ for ..
-rw-------@ for .DS_Store

drwxr-xr-x  for most folders
drwxr-xr-x@ for some folders

-rw-r--r--  for some files
-rw-r--r--@ for some files

My Documents directories have permissions like this:

drwx---r-x+ for .
drwx---r-x+ for ..
-rw----r--@ for .DS_Store

drwx---r-x+ for (all?) folders

-rw----r--@ for some files
-rw----r--+ for some files

It looks like everything that should have group read access is missing it. I realize that chmod can help, and that it has a -R recursive option, but I'm reluctant to start experimenting and mess things up more. In particular, I don't want to set group read in places where it shouldn't be there. Also, I want to change just some bits, leaving the others alone.

Can anyone provide advice about getting this fixed?

Not sure if it's relevant, but I got into this by trying to allow another user on the same machine read/write access to my main user's Documents. In sharing prefs, I tried adding the Documents folder to the list of shared folders and setting everyone to read (or at least read), but in the process, I think I deleted the "staff" group, whatever that is.

Answer 1

In a pinch, you can add group read/write permissions by entering your Documents directory and issuing:

chmod -R g+rw *

If you need to fix the ownership you can do:

chown -R user.group *

[Obviously you replace user and group with actual an user and group name]

Now you just need to fix the directories.

find . -type d | replace ' ' '\ ' | xargs chmod g+x

The above call finds all directories, then escapes spaces with a backslash (required for passing to xargs), then adds group execute permissions to each. The replace command is part of mysql. If you don't have that you can use sed 's/ /\\ /g'

Disclaimer that my Linux distro is Slackware. I would expect this to work on Mac, but I can't test. You can replace xargs chmod g+x with echo | more if you want to do a sanity check.

Note that you can pipe the output to file first:

find . -type d | replace ' ' '\ ' > dirs.txt

Then you can review that file and use a text editor to remove any directories you don't want to change. Then instead of the recursive calls to chmod, you can do:

cat dirs.txt | sed 's/$/\/*/' | xargs chmod g+rw
cat dirs.txt | xargs chmod +x

The sed call just replaces the end of each line with '/*' to mean all files in directory.

Answer 2

If I recall, the + attribute after the standard ls rwxrwxrwx signals ACLs. I'd be careful because your group read access might be a part of the ACL scheme.