At the moment, I paste files to a directory in Linux and it sets the following permissions:
rwxr--r--
What I'm trying to do is to set the permission to
rwxrw-r-- (group write)
automatically when I paste a new file into that folder or after a given period, preferably the one more efficient.
There must be an elegant solution to that already, if so can you point me the direction, please?
These "default rights" are called "umask" in the UNIX world (see wiki).
I think your problem can be solved by appending a umask command to the /etc/profile script:
umask 013
Depending on your distributive, there can also be other ways to set umask.