.\" $Id: login.defs.5,v 1.17 2005/04/26 12:16:36 kloczek Exp $
.\" Copyright 1991 - 1993, Julianne Frances Haugh and Chip Rosenthal
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.TH LOGIN.DEFS 5
.SH NAME
/etc/login.defs \- shadow password suite configuration
.SH DESCRIPTION
The
\fI/etc/login.defs\fR file defines the site\-specific configuration for the
shadow password suite. This file is required. Absence of this file will
not prevent system operation, but will probably result in undesirable
operation.
.PP
This file is a readable text file, each line of the file describing one
configuration parameter. The lines consist of a configuration name and
value, separated by whitespace. Blank lines and comment lines are ignored. 
Comments are introduced with a `#' pound sign and the pound sign must be the
first non\-white character of the line.
.PP
Parameter values may be of four types:  strings, booleans, numbers, and long
numbers. A string is comprised of any printable characters. A boolean should
be either the value ``yes'' or ``no''. An undefined boolean parameter or one
with a value other than these will be given a ``no'' value. Numbers (both
regular and long) may be either decimal values, octal values (precede the
value with ``0'') or hexadecimal values (precede the value with ``0x''). 
The maximum value of the regular and long numeric parameters is
machine\-dependent.
.PP
The following configuration items are provided:
.\"
.IP "CHFN_AUTH (boolean)"
If \fIyes\fR, the \fBchfn\fR and \fBchsh\fR programs will require
authentication before making any changes, unless run by the superuser.
.\"
.IP "CHFN_RESTRICT (string)"
This parameter specifies which values in the \fIgecos\fR field of the
\fI/etc/passwd\fR file may be changed by regular users using the \fBchfn\fR
program. It can be any combination of letters \fIf\fR, \fIr\fR, \fIw\fR,
\fIh\fR, for Full name, Room number, Work phone, and Home phone,
respectively. For backward compatibility, "yes" is equivalent to "rwh" and
"no" is equivalent to "frwh". If not specified, only the superuser can make
any changes. The most restrictive setting is better achieved by not
installing chfn SUID.
.\"
.IP "CREATE_HOME (boolean)"
This defines whether useradd should create home directories for users by
default. This option is OR'ed with the \fI\-m\fR flag on useradd command line.
.\"
.IP "GID_MAX (number)"
.IP "GID_MIN (number)"
Range of group IDs to choose from for the \fBuseradd\fR and \fBgroupadd\fR
programs.
.\"
.IP "MAIL_DIR (string)"
The mail spool directory. This is needed to manipulate the mailbox when its
corresponding user account is modified or deleted. If not specified, a
compile\-time default is used.
.\"
.IP "PASS_MAX_DAYS (number)"
The maximum number of days a password may be used. If the password is older
than this, a password change will be forced. If not specified, \-1 will be
assumed (which disables the restriction).
.IP "PASS_MIN_DAYS (number)"
The minimum number of days allowed between password changes. Any password
changes attempted sooner than this will be rejected. If not specified, \-1
will be assumed (which disables the restriction).
.IP "PASS_WARN_AGE (number)"
The number of days warning given before a password expires. A zero means
warning is given only upon the day of expiration, a negative value means no
warning is given. If not specified, no warning will be provided.
.PP
PASS_MAX_DAYS, PASS_MIN_DAYS and PASS_WARN_AGE
are only used at the time of account creation. Any changes to these
settings won't affect existing accounts.
.\"
.IP "UID_MAX (number)"
.IP "UID_MIN (number)"
Range of user IDs to choose from for the \fBuseradd\fR program.
.\"
.IP "UMASK (number)"
The permission mask is initialized to this value. If not specified,
the permission mask will be initialized to 077.
.\"
.IP "USERDEL_CMD (string)"
If defined, this command is run when removing a user.
It should remove any at/cron/print jobs etc. owned by
the user to be removed (passed as the first argument).
.\"
.SH CROSS REFERENCE
The following cross reference shows which programs in the shadow password
suite use which parameters.
.na
.IP chfn 12
CHFN_AUTH CHFN_RESTRICT
.IP chsh 12
CHFN_AUTH
.IP groupadd 12
GID_MAX GID_MIN
.IP newusers 12
PASS_MAX_DAYS PASS_MIN_DAYS PASS_WARN_AGE
UMASK
.IP pwconv 12
PASS_MAX_DAYS PASS_MIN_DAYS PASS_WARN_AGE
.IP useradd 12
CREATE_HOME
GID_MAX GID_MIN
PASS_MAX_DAYS PASS_MIN_DAYS PASS_WARN_AGE
UID_MAX UID_MIN
UMASK
.IP userdel 12
MAIL_DIR
USERDEL_CMD
.IP usermod 12
MAIL_DIR
.ad
.SH BUGS
Much of the functionality that used to be provided by the shadow password
suite is now handled by PAM. Thus, \fI/etc/login.defs\fR is no longer used
by programs such as
.BR login (1),
.BR passwd (1)
and
.BR su (1).
Please refer to the corresponding PAM configuration files instead.
.SH SEE ALSO
.BR login (1),
.BR passwd (1),
.BR su (1),
.BR passwd (5),
.BR shadow (5),
.BR pam (8)
.SH AUTHORS
Julianne Frances Haugh (jockgrrl@ix.netcom.com)
.br
Chip Rosenthal (chip@unicom.com)