I need to make sure that all users in a group have read/write access to all files in a shared folder, old and new files.
First, make sure that all existing files and folders are in the group
chgrp group . -R
And all new files and folders must be in the same group too
chmod g+s . -R
Finally, the files created by all users must have read/write permissions to the group. We must ensure what this command is run whenever a user logs on system.
We can ensure that by adding this line to /etc/bashrc.