How can I add account privileges to a newly created file?

Question

I have multipe accounts on my Mac.  Two of them need to share certain files, but not with everyone else so I can't use the Shared folder.  When I create a new text file with AppleScript it has default ownership to the account that created it, but I need to give read & write privilages to it to the other account as well.  I can do this manually, but there are lots of files sometimes.  One trick I've found is to reset privilages from the next higher folder.  This saves time, but sometimes I forget.  Also when I do this it causes Time Machine to think all the files in that folder have been updated.  If the folder is large it may cause Time Machine to purge a old backup version.  What I'd like to do is find some AppleScript code I can use to add user "A" with read & write access to the permissions of a new file at the time my AppleScript creates that file.  Any ideas?

Answer 1

Thanks for the reference.  It was interesting and provided me with a direction I hadn't thought of: User Groups and Terminal commands which led to DO SHELL SCRIPT.
The approach in your reference wasn't practical for me because I already have about 10,000 folders in a 4-deep tree structure on a 2 TB hard disk.  The inheritance method whould have taken a lot of work.
I did some more researching and experimentation and here's what I ended up with.
First I created a User Group and assigned the two accounts that needed to share files to it.  By the way, I have two accounts so I can run time-consuming AppleScripts in one while doing work in the other.  This way I'm not disturbed by the AppleScripts and, since some of them use System Events, they aren't disturbed by me.  Anyway, I set up a User Group.  For some reason, the first group didn't work properly.  When I assigned it to a folder or file, one of the account names appeared next to the group icon in the Get Info window of Finder.  I tried everything I could think of to make it work and failed.  Then I created a second User Group and it worked fine, so I just deleted the first group.  I wonder what went wrong the first time?
Next I used the Finder's Get Info window to apply the new Group privilages to all items in my very large shared data folder on that hard drive.  This took about an hour.
Finally I created the following AppleScript code taking most of it from what I found on the Internet and fixing problems using other things found on the net.  I've built the following code into a number of AppleScripts that create folders containing 20-200 files.  I've run two of the scripts and created about 200 files in a few dozen folders and it seems to work fine.  Oh, one more thing: For some reason I couldn't assign group membership by name.  I kept getting an error message.  When I substitued the group number - 505, it worked fine.  Go figure!
tell application "Finder"
... lots of finder code ...
set these_items to every item in folder (target_folder & folder_name)
tell me
                                        set this_POSIX to quoted form of POSIX path of ((target_folder & folder_name) as alias)
                                        do shell script "chown -R  " & "Programming:505 " & this_POSIX user name "Richard" password "xxx" with administrator privileges
                                        do shell script "chmod -R 770 " & this_POSIX user name "Richard" password "xxx" with administrator privileges
                                        repeat with this_item in these_items
                                                  set this_POSIX to quoted form of POSIX path of (this_item as alias)
                                                  do shell script "chown -R  " & "Programming:505 " & this_POSIX user name "Richard" password "xxx" with administrator privileges
                                                  do shell script "chmod -R 770 " & this_POSIX user name "Richard" password "xxx" with administrator privileges
                                        end repeat
                              end tell
...more finder code
end tell
Note: The tell me was recommended by someone on the net.  There was a caution about do shell script failing inside a Tell application "Finder".  I didn't test this.
I'm a happy camper now.  I don't think I'd have found my way without the reference you provided.