Be root. The group ID number (here called nnn, is for ling 503) is found in /etc/group
Add a new group called newname:
/usr/sbin/groupadd -g nnn newname RET
Add members to this group: Open the file /etc/group, and add a line that looks the same as the line for the groups cvs and ling.
Check group membership: Be root, and give the command
to check which groups trond belongs to.
Group attribute for files
The relevant commands are
chown trond -R directory/
chgrp ling -R directory
to change to owner trond and group owner ling.