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.Dd May 10, 2007 29.Dt NOLOGIN 5 30.Os 31.Sh NAME 32.Nm nologin 33.Nd disallow logins 34.Sh DESCRIPTION 35Programs such as 36.Xr login 1 37disallow logins if the 38.Nm 39file exists. 40The programs display the contents of 41.Nm 42to the user if possible and interrupt the login sequence. 43This makes it simple to temporarily prevent incoming logins systemwide. 44.Pp 45To disable logins on a per-account basis, 46investigate 47.Xr nologin 8 . 48.Sh SECURITY 49The 50.Nm 51file is ignored for user root by default. 52.Sh IMPLEMENTATION NOTES 53The 54.Nm 55feature is implemented through 56.Xr login.conf 5 , 57which allows to change the pathname of the 58file and to extend the list of users 59exempt from temporary login restriction. 60.Pp 61PAM-aware programs can be selectively configured to respect 62.Nm 63using the 64.Xr pam_nologin 8 65module via 66.Xr pam.conf 5 . 67.Pp 68The 69.Nm 70file will be removed at system boot if it resides in 71.Pa /var/run 72and 73.Va cleanvar_enable 74is set to 75.Dq Li YES 76in 77.Xr rc.conf 5 , 78which is default. 79Therefore system reboot can effectively re-enable logins. 80.Sh FILES 81.Bl -tag -width ".Pa /var/run/nologin" -compact 82.It Pa /var/run/nologin 83default location of 84.Nm 85.El 86.Sh SEE ALSO 87.Xr login 1 , 88.Xr login.conf 5 , 89.Xr pam.conf 5 , 90.Xr rc.conf 5 , 91.Xr nologin 8 , 92.Xr pam_nologin 8 , 93.Xr shutdown 8 94