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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] [-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 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
	     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 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
	     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 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 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 limits 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 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.

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.

     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, 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 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
		discarded.

		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‐
		carded.

		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
		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 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
	     databases.

     -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.

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), login.conf(5),
     passwd(5), pw(8), pwd_mkdb(8), vipw(8)

     and Robert Morris and Ken Thompson, UNIX Password security.

HISTORY
     The chpass utility appeared in 4.3BSD-Reno.

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

BSD			       December 30, 1993			   BSD
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