1.\" Copyright (c) 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)nologin.8 8.1 (Berkeley) 6/19/93 29.\" 30.Dd May 10, 2007 31.Dt NOLOGIN 5 32.Os 33.Sh NAME 34.Nm nologin 35.Nd disallow logins 36.Sh DESCRIPTION 37Programs such as 38.Xr login 1 39disallow logins if the 40.Nm 41file exists. 42The programs display the contents of 43.Nm 44to the user if possible and interrupt the login sequence. 45This makes it simple to temporarily prevent incoming logins systemwide. 46.Pp 47To disable logins on a per-account basis, 48investigate 49.Xr nologin 8 . 50.Sh SECURITY 51The 52.Nm 53file is ignored for user root by default. 54.Sh IMPLEMENTATION NOTES 55The 56.Nm 57feature is implemented through 58.Xr login.conf 5 , 59which allows to change the pathname of the 60file and to extend the list of users 61exempt from temporary login restriction. 62.Pp 63PAM-aware programs can be selectively configured to respect 64.Nm 65using the 66.Xr pam_nologin 8 67module via 68.Xr pam.conf 5 . 69.Pp 70The 71.Nm 72file will be removed at system boot if it resides in 73.Pa /var/run 74and 75.Va cleanvar_enable 76is set to 77.Dq Li YES 78in 79.Xr rc.conf 5 , 80which is default. 81Therefore system reboot can effectively re-enable logins. 82.Sh FILES 83.Bl -tag -width ".Pa /var/run/nologin" -compact 84.It Pa /var/run/nologin 85default location of 86.Nm 87.El 88.Sh SEE ALSO 89.Xr login 1 , 90.Xr login.conf 5 , 91.Xr pam.conf 5 , 92.Xr rc.conf 5 , 93.Xr nologin 8 , 94.Xr pam_nologin 8 , 95.Xr shutdown 8 96