CHPASS(1) BSD General Commands Manual CHPASS(1)
chpass, chfn, chsh -- add 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:
-a 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 (``:'') sepa-
rated list of all the user database fields, although they may be empty.
-s The -s option attempts to change the user's shell to newshell.
-l 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 data-
-y 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:
Login: user's login name
Password: user's encrypted password
Uid: user's login
Gid: user's login group
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 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 termcap(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 alterna-
tive 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.
/etc/master.passwd The user database
/etc/passwd A Version 7 format password file
/etc/ptmp Lock file for the passwd database
/tmp/pw.XXXXXX Temporary copy of the user passwd information
/etc/shells The list of approved shells
finger(1), login(1), passwd(1), pwhash(1), getusershell(3), passwd(5), passwd.conf(5),
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.
BSD October 7, 2006 BSD