CHPASS(1)

NAME
chpass - add or change user database information

SYNOPSIS
chpass [ -a list ] [ user ]

DESCRIPTION
Chpass allows editing of the user database information associated with user or, by default, the current user. The information is formatted and supplied to an editor for changes. The vi editor will be used unless the environmental variable EDITOR selects an alternate editor. When the editor terminates, the information is re-read and used to update the user database itself. Only the user, or the super-user, may edit the information associated with the user.

Only the information that the user is allowed to change is displayed.

Possible display items are as follows:

     Login:    user's login name
     Password:    user's encrypted password
     Uid:    user's id
     Gid:    user's login group id
     Change:    password change time
     Expire:    account expiration time
     Class:    user's general classification
     Home Directory:    user's home directory
     Shell:    user's login shell
     Full Name:    user's real name
     Location:    user's normal location
     Home Phone:    user's home phone
     Office Phone:    user's office phone

The login field is the user name used to access the computer account.

The password field contains the encrypted form of the user's password.

The uid field is the number associated with the login field. Both of these fields should be unique across the system (and often across a group of systems) as they control file access.

While it is possible to have multiple entries with identical login names and/or identical user id's, it is usually a mistake to do so. Routines that manipulate these files will often return only one of the multiple entries, and that one by random selection.

The group field is the group that the user will be placed in upon login. Since this system supports multiple groups (see groups(1)) this field currently has little special meaning. This field may be filled in with either a number or a group name (see group(5)).

The change field is the date by which the password must be changed.

The expire field is the date on which the account expires.

Both the change and expire fields should be entered in the form ``month day year'' where month is the month name (the first three characters are sufficient), day is the day of the month, and year is the year.

The class field is currently unused. In the near future it will be a key to a termcap(5) style database of user attributes.

The user's home directory is the full UNIX path name where the user will be placed on login.

The shell field is the command interpreter the user prefers. If the shell field is empty, the Bourne shell (/bin/sh) is assumed.

When altering a login shell, and not the super-user, the user must select an approved shell from the list in /etc/shells.

The last four fields are for storing the user's full name, office location, and home and work telephone numbers.

The super-user is also allowed to directly supply a user database entry, in the format specified by passwd(5), as an argument to the -a option. This argument must be a colon (``:'') separated list of all the user database fields, although they may be empty.

Once the information has been verified, chpass uses mkpasswd(8) to update the user database. This is run in the background, and, at very large sites could take several minutes. Until this update is completed, the password file is unavailable for other updates and the new information will not be available to programs.

FILES
/etc/master.passwd    The user database
/etc/shells    The list of approved shells

SEE ALSO
login(1), finger(1), getusershell(3), passwd(5), mkpasswd(8), vipw(8)
Robert Morris and Ken Thompson, UNIX password security

BUGS
User information should (and eventually will) be stored elsewhere.