Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
CHPASS(1)		  BSD General Commands Manual		     CHPASS(1)

NAME
     chpass, chfn, chsh, ypchpass, ypchfn, ypchsh -- add or change user	data-
     base information

SYNOPSIS
     chpass [-a	list] [-p encpass] [-s newshell] [user]

DESCRIPTION
     The chpass	program	allows editing of the user database information	asso-
     ciated 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 argu-
	   ment	must be	a colon	(``:'')	separated list of all the user data-
	   base	fields,	although they may be empty.

     -p	   The super-user is allowed to	directly supply	an encrypted password
	   field, in the format	used by	crypt(3), as an	argument.

     -s	   The -s option attempts 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
	   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	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 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	alter-
     ing 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.

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

NIS INTERACTION
     Chpass can	also be	used in	conjunction with NIS, however some restric-
     tions 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 su-
     per-user on the NIS master	server,	chpass (and, similarly,	passwd(1)) can
     not 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, including 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 access 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 su-
		per-user.  While support for changing other fields could be
		added, this would lead to compatibility	problems with other
		NIS-capable systems.  Even though the super-user may supply
		data for other fields while editing an entry, the extra	infor-
		mation (other than the password	-- see below) will be silently
		discarded.

		Exception: the super-user on the NIS master server is permit-
		ted to change any field.

	   2.	Password authentication	is required. Chpass will prompt	for
		the user's NIS password	before effecting any changes. If the
		password is invalid, all changes will be discarded.

		Exception: the super-user on the NIS master server is allowed
		to submit changes without supplying a password.	(The super-
		user may choose	to turn	off this feature using the -o flag,
		described below.)

	   3.	Adding new records to the local	password database is
		discouraged. Chpass 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 permitted 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).  Chpass
		tries to update	the local password database by default;	to up-
		date 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 ``Pass-
		word:''	field does not show up in the editor template, the su-
		per-user may add it back by hand), but even the	super-user
		must supply the	user's original	password otherwise
		rpc.yppasswdd(8) will refuse to	update the NIS maps.

		Exception: the super-user on the NIS master server is permit-
		ted 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	   The -l flag forces chpass to	modify the local copy of a user's
	   password information	in the even that a user	exists in both the lo-
	   cal and NIS databases.

     -y	   This	flag has the opposite effect of	-l.  This flag is largely re-
	   dundant since chpass	operates on NIS	entries	by default if NIS is
	   enabled.

     -d	domain
	   Specify a particular	NIS domain.  Chpass uses the system domain
	   name	by default, as set by the domainname(1)	command. The -d	option
	   can be used to override a default, 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 config-
	   ured	as NIS clients,	there is no way	for the	program	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 do-
	   main	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 communicating 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

SEE ALSO
     finger(1),	login(1), passwd(1), getusershell(3), passwd(5), pwd_mkdb(8),
     vipw(8)

     and Robert	Morris and Ken Thompson, UNIX Password security.

NOTES
     The chfn(1), chsh(1), ypchpass(1),	ypchfn(1) and ypchsh(1)	commands are
     really only links to chpass.

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

HISTORY
     The chpass, command appeared in 4.3BSD-Reno.

BSD			       December	30, 1993			   BSD

NAME | SYNOPSIS | DESCRIPTION | ENVIRONMENT | NIS INTERACTION | FILES | SEE ALSO | NOTES | BUGS | HISTORY

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=chpass&sektion=1&manpath=FreeBSD+2.2.5-RELEASE>

home | help