Anyways, the point is that I have to implement a shell(same as
newgrp). But just wondering, how is that feasble.

as for example, I have command df which has to be executed from new
group. if I have the new group ready, how do i set the df command to
be executed by users of that group? I mean imagine if my group id is
140, what do i set in df so that only users after entering the group
(gid 140) will be able to execute?

I have to have all these automated, as all these are supposed to be in
rootfilesystem and not in PC's. I am planning to write all scripts to
automate when my target boots up and runs.

Thanks for all the help,
zix