My system installation script (similar to install.site, run right after the system was installed, and before first boot) attempts to configure a user account using sometime pretty much like this:
/usr/sbin/useradd -mv -b /home -c "name of user" -u 2002 -g wheel -s /bin/ksh -p 'encrypted-password' foo When I did this, it created the user, but did not add the user to the group wheel. Based on the man page, I was expecting the -g option to do so: useradd -D [-b base-dir] [-e expiry-time] [-f inactive-time] [-g gid | name | =uid] [-k skel-dir] [-L login-class] [-r low..high] [-s shell] useradd [-mov] [-b base-dir] [-c comment] [-d home-dir] [-e expiry-time] [-f inactive-time] [-G secondary-group[,group,...]] [-g gid | name | =uid] [-k skel-dir] [-L login-class] [-p password] [-r low..high] [-s shell] [-u uid] user -g gid | groupname | =uid sets the default group for new users. But it didn't, the user was created with gid 0. When I changed the above command to use -G instead of -g, it worked. Why? Am I just not understanding the documentation for useradd?