.\" $OpenBSD: passwd.5,v 1.23 2002/03/27 18:10:38 millert Exp $ .\" $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 master.passwd file, readable only by root, consists of newline-separated records, one per user, containing ten colon .Pq Ql \&: separated fields. These fields are as follows: .Pp .Bl -tag -width password -offset indent -compact .It name User's login name. .It password User's .Em encrypted password. .It uid User's login user ID. .It gid User's login group ID. .It class User's general classification (see .Xr login.conf 5 ) . .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 publicly-readable .Nm passwd file is generated from the .Nm master.passwd file by .Xr pwd_mkdb 8 and has the class, change, and expire fields removed. Also, the encrypted password field is replaced by an asterisk .Pq Ql \&* . .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 IDs, 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 .Pq Ql \&- ; also, it is strongly suggested that neither uppercase characters nor dots .Pq Ql \&. 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 .Nm master.passwd contains the encrypted user passwords, it 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 login.conf 5 . It can be different for local and YP passwords. .Pp The .Ar 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 used by .Xr login 1 and other programs to determine which entry in the .Xr login.conf 5 database should be used. .Pp The .Ar change field is the number in seconds, 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, 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 .Pq Ql \&, separated subfields as follows: .Pp .Bl -tag -width office -offset indent -compact .It name User's full name. .It office User's office location. .It wphone User's work phone number. .It hphone User's home phone number. .El .Pp The full name may contain an ampersand .Pq Ql \&& , which will be replaced by the capitalized login name when the gecos field is displayed or used by various programs such as .Xr finger 1 , .Xr sendmail 8 , etc. .Pp The office and phone number subfields, if they exist, are used by the .Xr finger 1 program and possibly by other applications. .Pp The user's home directory is the full .Tn UNIX path name where the user will be placed on login. .Pp The .Ar 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 passwd file also supports standard YP exclusions and inclusions, based on user names and netgroups. .Pp Lines beginning with a .Ql \&- (minus sign) are entries marked as being excluded from any following inclusions, which are marked with a .Ql + (plus sign). .Pp If the second character of the line is a .Ql @ (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 .Ql + 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 overridden. 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::: .Sh SEE ALSO .Xr chpass 1 , .Xr login 1 , .Xr passwd 1 , .Xr getpwent 3 , .Xr login.conf 5 , .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 .Bx 4.3 . The following .Xr awk 1 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. To set .Ar change and .Ar expire use the current day in seconds from the epoch plus the number of seconds of offset desired. .Bd -literal -offset indent BEGIN { FS = ":"} { print $1 ":" $2 ":" $3 ":" $4 "::0:0:" $5 ":" $6 ":" $7 } .Ed .Sh HISTORY A .Nm passwd file format appeared in .At v3 . .Pp The YP file format first appeared in SunOS.