'\" t
.\"     Title: sulogin
.\"    Author: [see the "AUTHOR(S)" section]
.\" Generator: Asciidoctor 2.0.20
.\"      Date: 2024-01-31
.\"    Manual: System Administration
.\"    Source: util-linux 2.40
.\"  Language: English
.\"
.TH "SULOGIN" "8" "2024-01-31" "util\-linux 2.40" "System Administration"
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.SH "NAME"
sulogin \- single\-user login
.SH "SYNOPSIS"
.sp
\fBsulogin\fP [options] [\fItty\fP]
.SH "DESCRIPTION"
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\fBsulogin\fP is invoked by \fBinit\fP when the system goes into single\-user mode.
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The user is prompted:
.sp
Give root password for system maintenance (or type Control\-D for normal startup):
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If the root account is locked and \fB\-\-force\fP is specified, no password is required.
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\fBsulogin\fP will be connected to the current terminal, or to the optional \fItty\fP device that can be specified on the command line (typically \fI/dev/console\fP).
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When the user exits from the single\-user shell, or presses control\-D at the prompt, the system will continue to boot.
.SH "OPTIONS"
.sp
\fB\-e\fP, \fB\-\-force\fP
.RS 4
If the default method of obtaining the root password from the system via \fBgetpwnam\fP(3) fails, then examine \fI/etc/passwd\fP and \fI/etc/shadow\fP to get the password. If these files are damaged or nonexistent, or when root account is locked by \*(Aq!\*(Aq or \*(Aq*\*(Aq at the begin of the password then \fBsulogin\fP will \fBstart a root shell without asking for a password\fP.
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Only use the \fB\-e\fP option if you are sure the console is physically protected against unauthorized access.
.RE
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\fB\-p\fP, \fB\-\-login\-shell\fP
.RS 4
Specifying this option causes \fBsulogin\fP to start the shell process as a login shell.
.RE
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\fB\-t\fP, \fB\-\-timeout\fP \fIseconds\fP
.RS 4
Specify the maximum amount of time to wait for user input. By default, \fBsulogin\fP will wait forever.
.RE
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\fB\-h\fP, \fB\-\-help\fP
.RS 4
Display help text and exit.
.RE
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\fB\-V\fP, \fB\-\-version\fP
.RS 4
Print version and exit.
.RE
.SH "ENVIRONMENT"
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\fBsulogin\fP looks for the environment variable \fBSUSHELL\fP or \fBsushell\fP to determine what shell to start. If the environment variable is not set, it will try to execute root\(cqs shell from \fI/etc/passwd\fP. If that fails, it will fall back to \fI/bin/sh\fP.
.SH "AUTHORS"
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\fBsulogin\fP was written by Miquel van Smoorenburg for sysvinit and later ported to util\-linux by Dave Reisner and Karel Zak.
.SH "REPORTING BUGS"
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For bug reports, use the issue tracker at \c
.URL "https://github.com/util\-linux/util\-linux/issues" "" "."
.SH "AVAILABILITY"
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The \fBsulogin\fP command is part of the util\-linux package which can be downloaded from \c
.URL "https://www.kernel.org/pub/linux/utils/util\-linux/" "Linux Kernel Archive" "."