====== Managing User Accounts ======

You'll need to be the root user to do any of the following.

===== Adding a New Group =====

To add a new user group to the system you need to add an entry to the ///etc/group// file.

The entry format is: "<group name>:*:<group id>:"

The group ids already used by MINIX are 0-11, 26, and 99.

You can edit the ///etc/group// file with any text editor or do the following: 
<code>
# Add the 'wheel' user group with the group id of 12.
echo 'wheel:*:12:' >> /etc/group
</code>

{i} On MINIX 3.2.0, use the //group add// command:
<code>
group add wheel
</code>

===== Adding a New User =====

To add a new user to the system run the //adduser// command. The arguments to adduser are the user name, the group name, and the user's home directory. The group must already exist and the user must not.

Examples:
<code>
adduser foo other /home/foo

adduser anotherroot operator /root2

adduser mike staff /home/mike

adduser steve management /home/steve

adduser fred boss /home/fred

</code>

The typical values for new users is //other// (for ordinary users) or //operator// (for system administrator) for the group, and ///home/<user name>// for the home directory.

{i} On MINIX 3.2.0:
<code>
user add -m -g users foo

user add -m -d /root2 -g operator anotherroot
</code>

The new user's full name and password will be unset and the default shell will be //sh//.
To change them use the //chfn//, //passwd//, and //chsh// commands or have the user set them themselves after logging in.

Examples:
<code>
chfn foo 'Foo Bar'

chsh anotherroot /bin/zsh
</code>

{i} On MINIX 3.2.0, much of this can be changed using ''user mod [user]''.

==== Operator users ====

The system has been set up with the  idea  that  working  as
//root//  is  a bad thing to do.  As //root// you are in no way protected
from doing stupid things.  So do not do development as
root,  but  work  as  //bin//!  Only in exceptional cases do you
want to become //root//.  Being //root// is fun for wannabe hackers;
administrators know better.

To make life easier  for  //bin// some  programs  like  su([[http://www.minix3.org/manpages/man1/su.1.html|1]]),
install([[http://www.minix3.org/manpages/man1/install.1.html|1]]) 
and  shutdown([[http://www.minix3.org/manpages/man8/shutdown.8.html|8]]) 
treat //bin// and other members of
the //operator// group as special and allow them the  privileges
of  //root//.   (//One//  is an //operator// if //one// 's group id is zero.)
//Operator//s should share the shadow password of root by having
''##root''
in their password field.  This way they all have one
face (password) to the outside  world,  forming  no  greater
security risk than root alone.

==== Default Home Directory Contents ====

When you create a new user the contents of the ///usr/ast// directory is copied to the user's new home directory. To change the default files provided whenever a new user is created just change the contents of this directory.

===== Removing a User =====

To remove a user you will need to manually remove them from the ///etc/passwd// and ///etc/shadow// file.
This can be done in any text editor. The first field on each line is the user's login name.

You can also do the following to remove a user without editing the file by hand:
<code>
# Removing the user 'foobar'
grep -v '^foobar:' /etc/passwd > /tmp/passwd
mv /tmp/passwd /etc/passwd
grep -v '^foobar:' /etc/shadow > /tmp/shadow
mv /tmp/shadow /etc/shadow
</code>

Note that you will probably want to make a backup of the ///etc/passwd// and ///etc/shadow// files before doing this and then verify that the user you want to remove (and only the user you wanted to remove) is gone from the new passwd file before overwriting the old one (this can be done with //diff//.

Once the user is gone you can remove their home directory if you wish.

{i} On MINIX 3.2.0, this is different.

To remove a user:
<code>
user del foo
</code>

To remove a user and their home directory:
<code>
user del -r foo
</code>

===== Removing a Group =====

Removing a group is very similar to removing a user. All you need to do is edit the ///etc/group// file or the following:
<code>
# Removing the group named 'wheel'
grep -v '^wheel:' /etc/group > /tmp/group
mv /tmp/group /etc/group
</code>

{i} On MINIX 3.2.0:
<code>
group del wheel
</code>