Can somebody please explain to me the exact differences between useradd -b and useradd -d in [Debian] Linux? Both seem to work quite similar to me, but then I spot differences that confuse me.
difference between useradd -b and useradd -d
linux;debian;options;useradd
-b specifies the location of users' home directories.  On your average Debian box, this will be /home; you can change the default by editing /etc/default/useradd.  useradd will add the new username to this path to get the home directory.  This means that if you douseradd -b /somewhere ianthe new user's directory will be /somewhere/ian.-d sets the home directory explicitly, irrespective of defaults.  Souseradd -d /somewhere-else/ian ianthen the user's home directory will be set to /somewhere-else/ian.Note that the directory will be set in the password file, but won't actually be created unless -m is also specified (or the CREATE_HOME setting is enabled in the defaults file).