Permissions changing when file edited

[s&kp]

I am running Mac OS server 5.1.7 with OS x 10.11.6
I have a shared folder with permissions set as Read/Write for everyone. I have propagated these permissions using File Sharing on the Server to all child items.
The problem is that if someone then edits a file within that folder(eg. excel spreadsheet), the permissions of that file then change to Read only for everyone else except the person who made the change. I don't understand why the permissions are changing. How can I make the files stay as Read/Write for everyone ?

Thanks for your help. David

 

[NoBoMac]

Apologies if covering info you already know about...

Probably the individual's umask values are changing the permissions. And programs can basically set permissions how they feel (ie. might not preserve the original permissions and ownership values). By default, umasks are 022 which means deny write rights for the file for group and other. Owner retains full rights (umask is in owner-group-other format bit mask and masks out specific bits [4=read, 2=write, 1=execute; a mask value of 3 would be exclude write and execute rights, 077 would deny everybody but owner rights to file]).

The sharing dialog is somewhat limited, from what I recall. Really need to be using command line chmod command to setup ACLs for directories and files. Not sure if there is propagate option, but, can setup inheritances for file permissions and believe can setup so that modified files do not get changed. Have not needed to to this myself as have not maintained a file share for others, so, here's an ACL 101 page:

https://www.techrepublic.com/blog/a...troduction-to-os-x-access-control-lists-acls/

Can automate the process a bit by using the find command with -t and -exec switches.