.\" $NetBSD: passwd.5,v 1.4 1995/07/28 06:46:05 phil Exp $
.\"
.\" Copyright (c) 1988, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
.\" Portions Copyright (c) 1994, Jason Downs. All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\" must display the following acknowledgement:
.\" This product includes software developed by the University of
.\" California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" @(#)passwd.5 8.1 (Berkeley) 6/5/93
.\"
.Dd July 18, 1995
.Dt PASSWD 5
.Os
.Sh NAME
.Nm passwd
.Nd format of the password file
.Sh DESCRIPTION
The
.Nm passwd
files are files consisting of newline separated records, one per user,
containing ten colon (``:'') separated fields. These fields are as
follows:
.Pp
.Bl -tag -width password -offset indent
.It name
User's login name.
.It password
User's
.Em encrypted
password.
.It uid
User's id.
.It gid
User's login group id.
.It class
User's general classification (unused).
.It change
Password change time.
.It expire
Account expiration time.
.It gecos
General information about the user.
.It home_dir
User's home directory.
.It shell
User's login shell.
.El
.Pp
The
.Ar name
field is the login used to access the computer account, and the
.Ar uid
field is the number associated with it. They should both be unique
across the system (and often across a group of systems) since they
control file access.
.Pp
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.
.Pp
The login name must never begin with a hyphen (``-''); also, it is strongly
suggested that neither upper-case characters or dots (``.'') be part
of the name, as this tends to confuse mailers. No field may contain a
colon (``:'') as this has been used historically to separate the fields
in the user database.
.Pp
The password field is the
.Em encrypted
form of the password.
If the
.Ar password
field is empty, no password will be required to gain access to the
machine. This is almost invariably a mistake.
Because these files contain the encrypted user passwords, they should
not be readable by anyone without appropriate privileges.
.Pp
Which type of cipher is used to encrypt the password information
depends on the configuration in
.Xr passwd.conf 5 .
It can be different for local and YP passwords.
.Pp
The group field is the group that the user will be placed in upon login.
Since this system supports multiple groups (see
.Xr groups 1 )
this field currently has little special meaning.
.Pp
The
.Ar class
field is currently unused. In the near future it will be a key to
a
.Xr termcap 5
style database of user attributes.
.Pp
The
.Ar change
field is the number in seconds,
.Dv GMT ,
from the epoch, until the
password for the account must be changed.
This field may be left empty to turn off the password aging feature.
.Pp
The
.Ar expire
field is the number in seconds,
.Dv GMT ,
from the epoch, until the
account expires.
This field may be left empty to turn off the account aging feature.
.Pp
The
.Ar gecos
field normally contains comma (``,'') separated subfields as follows:
.Pp
.Bd -unfilled -offset indent
name user's full name
office user's office number
wphone user's work phone number
hphone user's home phone number
.Ed
.Pp
This information is used by the
.Xr finger 1
program.
.Pp
The user's home directory is the full
.Tn UNIX
path name where the user
will be placed on login.
.Pp
The shell field is the command interpreter the user prefers.
If there is nothing in the
.Ar shell
field, the Bourne shell
.Pq Pa /bin/sh
is assumed.
.Sh YP SUPPORT
If YP is active, the
.Nm
file also supports standard YP exclusions and inclusions, based on user
names and netgroups.
.Pp
Lines beginning with a ``-'' (minus sign) are entries marked as being excluded
from any following inclusions, which are marked with a ``+'' (plus sign).
.Pp
If the second character of the line is a ``@'' (at sign), the operation
involves the user fields of all entries in the netgroup specified by the
remaining characters of the
.Ar name
field.
Otherwise, the remainder of the
.Ar name
field is assumed to be a specific user name.
.Pp
The ``+'' token may also be alone in the
.Ar name
field, which causes all users from the
.Pa passwd.byname
and
.Pa passwd.byuid
YP maps to be included.
.Pp
If the entry contains non-empty
.Ar uid
or
.Ar gid
fields, the specified numbers will override the information retrieved
from the YP maps. As well, if the
.Ar gecos,
.Ar dir
or
.Ar shell
entries contain text, it will override the information included via YP.
On some systems, the
.Ar passwd
field may also be overriden, hence it is recommended that the standard
way to enable YP passwd support in
.Pa /etc/master.passwd
is:
.Pp
+:*::::::::
.Pp
which after
.Xr pwd_mkdb 8
will result in
.Pa /etc/passwd
containing:
.Pp
+:*:0:0:::
.Pp
.Sh SEE ALSO
.Xr chpass 1 ,
.Xr login 1 ,
.Xr passwd 1 ,
.Xr passwd.conf 5 ,
.Xr getpwent 3 ,
.Xr netgroup 5 ,
.Xr adduser 8 ,
.Xr pwd_mkdb 8 ,
.Xr vipw 8 ,
.Xr yp 8
.Pp
.%T "Managing NFS and NIS"
(O'Reilly & Associates)
.Sh BUGS
User information should (and eventually will) be stored elsewhere.
.Pp
Placing YP exclusions in the file after any inclusions will have
unexpected results.
.Sh COMPATIBILITY
The password file format has changed since 4.3BSD.
The following awk script can be used to convert your old-style password
file into a new style password file.
The additional fields
.Dq class ,
.Dq change
and
.Dq expire
are added, but are turned off by default.
Class is currently not implemented, but change and expire are; to set them,
use the current day in seconds from the epoch + whatever number of seconds
of offset you want.
.Bd -literal -offset indent
BEGIN { FS = ":"}
{ print $1 ":" $2 ":" $3 ":" $4 "::0:0:" $5 ":" $6 ":" $7 }
.Ed
.Sh HISTORY
A
.Nm
file format appeared in
.At v6 .
.Pp
YP file format first appeared in SunOS.