NAME

adduser − procedure for adding new users

DESCRIPTION

A new user must choose a login name, which must not already appear in /etc/passwd.  An account can be added by editing a line into the passwd file, with no password given, and giving a user and group id for the account.  User id’s should be distinct across a system, since they are used to control access to files.  Typically, users working on similar projects will be put in the same group.  Thus at UCB we have groups for system staff, faculty, graduate students, and a few special groups for large projects.  System staff is group “10” for historical reasons, and the super-user is in this group.  The su(1) program looks at your user and group id before it lets you become the super-user, and should implement whatever policy you choose to administer for limiting access to super-user privileges.

A skeletal account for a new user “ernie” would look like:

ernie::235:20:& Kovacs,508E,7925,6428202:/mnt/grad/ernie:/bin/csh

The first field is the login name “ernie”.  The next field is the encrypted password which is not given and can be initialized using passwd(1). The next two fields are the user and group id’s. Traditionally, users in group 20 are graduate students and have account names with numbers in the 200’s. The next field gives information about ernie’s real name, office and office phone and home phone. This information is used by the finger(1) program. From this information we can tell that ernie’s real name is “Ernie Kovacs” (the & here serves to repeat “ernie” with appropriate capitalization), that his office is 508 Evans Hall, his extension is x2-7925, and this his home phone number is 642-8202. You can modify the finger(1) program if necessary to allow different information to be encoded in this field.  The UCB version of finger knows several things particular to Berkeley − that phone extensions start “2−”, that offices ending in “E” are in Evans Hall and that offices ending in “C” are in Cory Hall.

The final two fields give a login directory and a login shell name.  Traditionally, user files live on the file system /mnt and there are subdirectories there for each group of users, i.e.: “/mnt/staff” and “/mnt/prof”.  The login shell will default to “/bin/sh” if none is given.  Most users at Berkeley choose “/bin/csh” so this is usually specified here. 

It is useful to give new users some help in getting started, supplying them with a few skeletal files such as .profile if they use “/bin/sh”, or .cshrc and .login if they use “/bin/csh”.  The directory “/usr/skel” contains skeletal definitions of such files.  New users should be given copies of these files which, for instance, arrange to use tset(1), msgs(1) and mail(1) automatically at each login.

FILES

/etc/passwdpassword file
/mnt/∗login directories
/usr/skelskeletal login directory

SEE ALSO

passwd(1), finger(1), chsh(1), chfn(1), passwd(5)

BUGS

We don’t say how to lock out the password file so you can’t get messed up if someone runs passwd(1) while you are editing it. We currently just don’t worry about this. The trick is to make a file “/etc/ptmp” so that passwd will say “Temporary file busy − try again”, and to remove it when you are done. 

3rd Berkeley Distribution