chpass(1)

NAME

chpass, chfn, chsh, ypchpass, ypchfn, ypchsh - add or change
user database information

SYNOPSIS

chpass  [-a list] [-p encpass] [-e expiretime] [-s newshell]
[user]
chpass [-oly] [-a list] [-p  encpass]  [-e  expiretime]  [-s
newshell]
       [-d domain] [-h host] [user]

DESCRIPTION

The chpass utility allows editing of the user database in
formation associated with user or, by default, the current user.
The chfn, chsh, ypchpass, ypchfn and ypchsh utilities behave
identically
to chpass. (There is only one program.)
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 (``:'') separated list; of all the
user database fields, although they may be empty.
-p The super-user is allowed to directly supply an en
crypted pass: word field, in the format used by crypt(3), as an; argument.
-e expiretime: Change the account expire time. This option is used; to set the
expire time from a script as if it was done in the; interactive
editor.
-s newshell: Attempt to change the user's shell to newshell.
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
Class: user's general classification
Change: password change time
Expire: account expiration time
Full Name: user's real name
Office Location: user's office location (1)
Office Phone: user's office phone (1)
Home Phone: user's home phone (1)
Other Information: any locally defined parameters for; user (1)
Home Directory: user's home directory
Shell: user's login shell; NOTE(1) - In the actual master.passwd file,; these fields
are comma-delimited fields embed

ded in the
FullName field.
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 class field references class descriptions in
/etc/login.conf and is typically used to initialize the user's system resource lim
its when they login.
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.
Five fields are available for storing the user's full name,
office location, work and home telephone numbers and finally other
information which is a single comma delimited string to represent any
additional gecos fields (typically used for site specific user informa
tion). Note that finger(1) will display the office location and office
phone together under the heading Office:.
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.
Once the information has been verified, chpass uses
pwd_mkdb(8) to update the user database.

ENVIRONMENT

The vi(1) editor will be used unless the environment vari
able EDITOR is set to an alternate editor. When the editor terminates, the
information is re-read and used to update the user database itself. On
ly the user, or the super-user, may edit the information associated with
the user.
See pwd_mkdb(8) for an explanation of the impact of setting
the PW_SCAN_BIG_IDS environment variable.

NIS INTERACTION

The chpass utility can also be used in conjunction with NIS,
however some
restrictions apply. Currently, chpass can only make changes
to the NIS passwd maps through rpc.yppasswdd(8), which normally only
permits changes to a user's password, shell and GECOS fields. Except when
invoked by the
super-user on the NIS master server, chpass (and, similarly,
passwd(1)) cannot use the rpc.yppasswdd(8) server to change other user
information or add new records to the NIS passwd maps. Furthermore,
rpc.yppasswdd(8) requires password authentication before it will make any
changes. The only user allowed to submit changes without supplying a
password is the super-user on the NIS master server; all other users, in
cluding those with root privileges on NIS clients (and NIS slave servers)
must enter a password. (The super-user on the NIS master is allowed to
bypass these restrictions largely for convenience: a user with root ac
cess to the NIS master server already has the privileges required to make
updates to the NIS maps, but editing the map source files by hand can be
cumbersome.
Note: these exceptions only apply when the NIS master server
is a FreeBSD system).
Consequently, except where noted, the following restrictions
apply when
chpass is used with NIS:: 1. Only the shell and GECOS information may be
changed. All
other fields are restricted, even when chpass is
invoked by the super-user. While support for changing other
fields could be added, this would lead to compatibility prob
lems with other NIS-capable systems. Even though the super-user
may supply data for other fields while editing an entry, the
extra information (other than the password -- see below)
will be silently discarded.
Exception: the super-user on the NIS master serv
er is permitted to change any field.
2. Password authentication is required. The chpass
utility will prompt for the user's NIS password before effect
ing any changes. If the password is invalid, all changes
will be discarded.
Exception: the super-user on the NIS master serv
er is allowed to submit changes without supplying a password.
(The superuser may choose to turn off this feature using
the -o flag, described below.)
3. Adding new records to the local password database
is
discouraged. The chpass utility will allow the
administrator to add new records to the local password database
while NIS is enabled, but this can lead to some confusion
since the new records are appended to the end of the master
password file, usually after the special NIS '+' entries. The
administrator should use vipw(8) to modify the local password
file when NIS is running.
The super-user on the NIS master server is per
mitted to add new records to the NIS password maps, provided
the rpc.yppasswdd(8) server has been started with the
-a flag to permitted additions (it refuses them by default).
The chpass
utility tries to update the local password
database by default; to update the NIS maps instead, invoke
chpass with the -y flag.
4. Password changes are not permitted. Users should
use passwd(1) or yppasswd(1) to change their NIS
passwords. The super-user is allowed to specify a new password
(even though the ``Password:'' field does not show up in the
editor template, the super-user may add it back by hand),
but even the super-user must supply the user's original pass
word otherwise rpc.yppasswdd(8) will refuse to update the NIS
maps.
Exception: the super-user on the NIS master serv
er is permitted to change a user's NIS password with chpass.
There are also a few extra option flags that are available
when chpass is
compiled with NIS support:
-l Force chpass to modify the local copy of a user's
password infor mation in the event that a user exists in both the
local and NIS databases.
-y Opposite effect of -l. This flag is largely redun
dant since
chpass operates on NIS entries by default if NIS is
enabled.
-d domain
Specify a particular NIS domain. The chpass utility
uses the system domain name by default, as set by the domain
name(1) utility. The -d option can be used to override a de
fault, or to specify a domain when the system domain name is not
set.
-h host
Specify the name or address of an NIS server to
query. Normally,
chpass will communicate with the NIS master host
specified in the master.passwd or passwd maps. On hosts that have
not been configured as NIS clients, there is no way for the pro
gram to determine this information unless the user provides the
hostname of a server. Note that the specified hostname need not
be that of the NIS master server; the name of any server, master or
slave, in a given NIS domain will do.
When using the -d option, the hostname defaults to
``localhost''. The -h option can be used in conjunction with the -d
option, in which case the user-specified hostname will override
the default.
-o Force the use of RPC-based updates when communicat
ing with rpc.yppasswdd(8) (``old-mode''). When invoked by
the super-user
on the NIS master server, chpass allows unrestricted
changes to the NIS passwd maps using dedicated, non-RPC-based
mechanism (in this case, a UNIX domain socket). The -o flag can
be used to
force chpass to use the standard update mechanism
instead. This option is provided mainly for testing purposes.

FILES

/etc/master.passwd the user database
/etc/passwd a Version 7 format password file
/etc/chpass.XXXXXX temporary copy of the password file
/etc/shells the list of approved shells

HISTORY

The chpass utility appeared in 4.3BSD-Reno.

BUGS

User information should (and eventually will) be stored
elsewhere.
BSD December 30, 1993

docs.sk

comprehensive documentation repository

See also