+++ /dev/null
-.\" Copyright (c) 1993 Michael Haardt (michael@moria.de),
-.\" Fri Apr 2 11:32:09 MET DST 1993
-.\"
-.\" %%%LICENSE_START(GPLv2+_DOC_FULL)
-.\" This is free documentation; you can redistribute it and/or
-.\" modify it under the terms of the GNU General Public License as
-.\" published by the Free Software Foundation; either version 2 of
-.\" the License, or (at your option) any later version.
-.\"
-.\" The GNU General Public License's references to "object code"
-.\" and "executables" are to be interpreted as the output of any
-.\" document formatting or typesetting system, including
-.\" intermediate and printed output.
-.\"
-.\" This manual is distributed in the hope that it will be useful,
-.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
-.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-.\" GNU General Public License for more details.
-.\"
-.\" You should have received a copy of the GNU General Public
-.\" License along with this manual; if not, see
-.\" <http://www.gnu.org/licenses/>.
-.\" %%%LICENSE_END
-.\"
-.\" Modified Sun Jul 25 10:46:28 1993 by Rik Faith (faith@cs.unc.edu)
-.\" Modified Sun Aug 21 18:12:27 1994 by Rik Faith (faith@cs.unc.edu)
-.\" Modified Sun Jun 18 01:53:57 1995 by Andries Brouwer (aeb@cwi.nl)
-.\" Modified Mon Jan 5 20:24:40 MET 1998 by Michael Haardt
-.\" (michael@cantor.informatik.rwth-aachen.de)
-.TH PASSWD 5 2015-02-01 "Linux" "Linux Programmer's Manual"
-.SH NAME
-passwd \- password file
-.SH DESCRIPTION
-The
-.IR /etc/passwd
-file is a text file that describes user login accounts for the system.
-It should have read permission allowed for all users (many utilities, like
-.BR ls (1)
-use it to map user IDs to usernames), but write access only for the
-superuser.
-.PP
-In the good old days there was no great problem with this general
-read permission.
-Everybody could read the encrypted passwords, but the
-hardware was too slow to crack a well-chosen password, and moreover the
-basic assumption used to be that of a friendly user-community.
-These days many people run some version of the shadow password suite, where
-.I /etc/passwd
-has an \(aqx\(aq character in the password field,
-and the encrypted passwords are in
-.IR /etc/shadow ,
-which is readable by the superuser only.
-.PP
-If the encrypted password, whether in
-.I /etc/passwd
-or in
-.IR /etc/shadow ,
-is an empty string, login is allowed without even asking for a password.
-Note that this functionality may be intentionally disabled in applications,
-or configurable (for example using the "nullok" or "nonull" arguments to
-pam_unix.so).
-.PP
-If the encrypted password in
-.I /etc/passwd
-is "\fI*NP*\fP" (without the quotes),
-the shadow record should be obtained from an NIS+ server.
-.PP
-Regardless of whether shadow passwords are used, many system administrators
-use an asterisk (*) in the encrypted password field to make sure
-that this user can not authenticate him- or herself using a
-password.
-(But see NOTES below.)
-.PP
-If you create a new login, first put an asterisk (*) in the password field,
-then use
-.BR passwd (1)
-to set it.
-.PP
-Each line of the file describes a single user,
-and contains seven colon-separated fields:
-.sp
-.RS
-name:password:UID:GID:GECOS:directory:shell
-.RE
-.sp
-The field are as follows:
-.TP 12
-.I name
-This is the user's login name.
-It should not contain capital letters.
-.TP
-.I password
-This is either the encrypted user password,
-an asterisk (*), or the letter \(aqx\(aq.
-(See
-.BR pwconv (8)
-for an explanation of \(aqx\(aq.)
-.TP
-.I UID
-The privileged
-.I root
-login account (superuser) has the user ID 0.
-.TP
-.I GID
-This is the numeric primary group ID for this user.
-(Additional groups for the user are defined in the system group file; see
-.BR group (5)).
-.TP
-.I GECOS
-This field (sometimes called the "comment field")
-is optional and used only for informational purposes.
-Usually, it contains the full username.
-Some programs (for example,
-.BR finger (1))
-display information from this field.
-.IP
-GECOS stands for "General Electric Comprehensive Operating System",
-which was renamed to GCOS when
-GE's large systems division was sold to Honeywell.
-Dennis Ritchie has reported: "Sometimes we sent printer output or
-batch jobs to the GCOS machine.
-The gcos field in the password file was a place to stash the
-information for the $IDENTcard.
-Not elegant."
-.TP
-.I directory
-This is the user's home directory:
-the initial directory where the user is placed after logging in.
-The value in this field is used to set the
-.B HOME
-environment variable.
-.TP
-.I shell
-This is the program to run at login (if empty, use
-.IR /bin/sh ).
-If set to a nonexistent executable, the user will be unable to login
-through
-.BR login (1).
-The value in this field is used to set the
-.B SHELL
-environment variable.
-.SH FILES
-.I /etc/passwd
-.SH NOTES
-If you want to create user groups, there must be an entry in
-.IR /etc/group ,
-or no group will exist.
-.PP
-If the encrypted password is set to an asterisk (*), the user will be unable
-to login using
-.BR login (1),
-but may still login using
-.BR rlogin (1),
-run existing processes and initiate new ones through
-.BR rsh (1),
-.BR cron (8),
-.BR at (1),
-or mail filters, etc.
-Trying to lock an account by simply changing the
-shell field yields the same result and additionally allows the use of
-.BR su (1).
-.SH SEE ALSO
-.BR chfn (1),
-.BR chsh (1),
-.BR login (1),
-.BR passwd (1),
-.BR su (1),
-.BR crypt (3),
-.BR getpwent (3),
-.BR getpwnam (3),
-.BR group (5),
-.BR shadow (5)
-.SH COLOPHON
-This page is part of release 3.79 of the Linux
-.I man-pages
-project.
-A description of the project,
-information about reporting bugs,
-and the latest version of this page,
-can be found at
-\%http://www.kernel.org/doc/man\-pages/.
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