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CHPASS(1) General Commands Manual CHPASS(1)


chpass, chfn, chshadd or change user database information


chpass [-a list] [-s newshell] [-l] [user]

chpass [-a list] [-s newshell] [-y] [user]


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.

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

The options are as follows:

The super-user is allowed to directly supply a user database entry, in the format specified by passwd(5), as an argument. This argument must be a colon (“:”) separated list of all the user database fields, although they may be empty.
The -s option attempts to change the user's shell to newshell.
This option causes the password to be updated only in the local password file. When changing only the local password, pwd_mkdb(8) is used to update the password databases.
This forces the YP password database entry to be changed, even if the user has an entry in the local database. The rpc.yppasswdd(8) daemon should be running on the YP master server.

Possible display items are as follows:

user's login name
user's encrypted password
user's login
user's login group
password change time
account expiration time
user's general classification
Home Directory:
user's home directory
user's login shell
Full Name:
user's real name
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 at login. Since BSD 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 a key for a user's login class. Login classes are defined in login.conf(5), which is a capfile(5) style database of user attributes, accounting, resource and environment settings.

The user's home directory is the full UNIX path name where the user will be placed at 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 may not change from a non-standard shell or to a non-standard shell. Non-standard is defined as a shell not found in /etc/shells.

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

Once the information has been verified, chpass uses pwd_mkdb(8) to update the user database.


The vi(1) editor will be used unless the environment variable EDITOR is set to an alternative 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.


The user database
A Version 7 format password file
Lock file for the passwd database
Temporary copy of the user passwd information
The list of approved shells


finger(1), login(1), passwd(1), pwhash(1), getusershell(3), passwd(5), passwd.conf(5), pwd_mkdb(8), vipw(8)

Robert Morris and Ken Thompson, UNIX Password Security.


The chpass command appeared in 4.3BSD-Reno.


This program's interface is poorly suited to cryptographic systems such as Kerberos, and consequently Kerberos password changing is not a feature of this program.

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

April 5, 2012 NetBSD 7.0