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.\" @(#)chpass.1 5.7 (Berkeley) %G%
chpass \- add or change user database information
chpass [ -a list ] [ -s shell ] [ user ]
allows editing of the user database information associated
or, by default, the current user.
The information is formatted and supplied to an editor for changes.
editor will be used unless the environmental variable EDITOR selects
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
Only the information that the user is allowed to change is displayed.
Possible display items are as follows:
Password: user's encrypted password
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
field is the user name used to access the computer account.
field contains the encrypted form of the user's password.
field is the number associated with the
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.
field is the group that the user will be placed in at login.
Since this system supports multiple groups (see
this field currently has little special meaning.
This field may be filled in with either a number or a group name (see
field is the date by which the password must be changed.
field is the date on which the account expires.
fields should be entered in the form ``month day year'' where
is the month name (the first three characters are sufficient),
is the day of the month, and
field is currently unused. In the near future it will be a key to
style database of user attributes.
The user's home directory is the full UNIX path name where the user
The shell field is the command interpreter the user prefers.
field is empty, the Bourne shell (\fI/bin/sh\fP) is assumed.
When altering a login shell, and not the super-user, the user
may not change from a non-standard shell or to a non-standard
Non-standard is defined as a shell not found in
The last four fields are for storing the user's full name, office
location, and home and work telephone numbers.
The options are as follows:
The super-user is allowed to directly supply a user database
entry, in the format specified by
This argument must be a colon (``:'') separated list of all the
user database fields, although they may be empty.
option attempts to change the user's shell to
Once the information has been verified,
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.
/etc/master.passwd The user database
/etc/shells The list of approved shells
login(1), finger(1), getusershell(3), passwd(5), mkpasswd(8), vipw(8)
Robert Morris and Ken Thompson,
.I UNIX password security
User information should (and eventually will) be stored elsewhere.