excel - auto calculations

If excel is not auto calculating then check -

TOOLS/OPTIONS/CALCULATION and make sure that the automatic option is selected under "Calculation".

unix user management commands

Various commands to create groups, add groups to users and make a group the default group.

Create New Group
# groupadd -g "groupid" "groupname"

Add Group to user, additional group
# usermod -G "groupname" "username"

Add Group to user, primary group
# usermod -g "groupname" "username"