.\" Portions Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved. .\" $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 , .Nm master.passwd .Nd format of the password file .Sh DESCRIPTION The /etc/passwd file is a legacy BSD 4.3 format file. It is mostly unused, but is updated by some utility programs. Its format is similar to the /etc/master.passwd file, except that it does not contain the .Ar class , .Ar change , and .Ar expire fields described below. .Pp The /etc/master.passwd file comprises newline separated records, one per user. Each line contains 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 User's full name. .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 .Ar 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 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 currently unused. .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 the user's full name. Note that Mac OS X differs from some other operating systems, where the .Ar gecos field may contain other comma-separcted information about the user. .Pp The .Ar home_dir field is the user's home directory. This is the full 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 INTERACTION WITH DIRECTORY SERVICES Processes generally find user records using one of the .Xr getpwent 3 family of functions. On Mac OS X, these functions interact with the .Xr DirectoryService 8 daemon, which reads the /etc/master.passwd file as well as searching other directory information services to find user accounts. .Sh FILES .Bl -tag -width /etc/master.passwd -compact .It Pa /etc/passwd .It Pa /etc/master.passwd .El .Sh SEE ALSO .Xr chpass 1 , .Xr login 1 , .Xr passwd 1 , .Xr getpwent 3 , .Xr netgroup 5 , .Xr DirectoryService 8 , .Xr pwd_mkdb 8 , .Xr vipw 8 .Pp .Sh HISTORY A .Nm passwd file format appeared in .At v6 .