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CHPASS(1)		  BSD General Commands Manual		     CHPASS(1)

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

     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]

     The chpass	utility	allows editing of the user database information	asso-
     ciated 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 en-
	     try, 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 encrypted 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

     -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 embedded 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 gid 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 limits when they

     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 information).	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	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.

     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 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.

     See pwd_mkdb(8) for an explanation	of the impact of setting the
     PW_SCAN_BIG_IDS environment variable.

     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, 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

     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 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

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

	   2.	Password authentication	is required.  The chpass utility will
		prompt for the user's NIS password before effecting any
		changes.  If the password is invalid, all changes will be dis-

		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.  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 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).  The chpass
		utility	tries to update	the local password database by de-
		fault; 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 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	     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

     -y	     Opposite effect of	-l.  This flag is largely redundant 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 domainname(1)	util-
	     ity.  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	con-
	     figured as	NIS clients, there is no way for the program to	deter-
	     mine 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 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.

     /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

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

     Robert Morris and Ken Thompson, UNIX Password security.

     The chpass	utility	appeared in 4.3BSD-Reno.

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

BSD			       December	30, 1993			   BSD


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