NetBSD/share/man/man8/rc.8

.\" 	$NetBSD: rc.8,v 1.18 2002/01/31 01:28:53 lukem Exp $
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.\" by Luke Mewburn.
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.Dd January 31, 2002
.Dt RC 8
.Os
.Sh NAME
.Nm rc ,
.Nm rc.shutdown ,
.Nm rc.d/
.Nd startup and shutdown scripts
.Sh SYNOPSIS
.Nm rc
.Nm rc.shutdown
.Nm rc.d/
.Sh DESCRIPTION
.Nm
is the command script which controls the startup of various services,
and is invoked by
.Xr init 8
as part of the process of entering the automatic reboot to multi-user startup,
or after the single user mode shell has exited.
If
.Xr init 8
is starting the automatic reboot process,
.Nm
is invoked with the argument of
.Sq autoboot .
.Pp
.Nm rc.shutdown
is the command script which shuts down various services, and is invoked by
.Xr shutdown 8
as part of the process of shutting down the system.
.Pp
.Nm rc.d/
is the directory which contains various scripts, one for each service,
which are called by
.Nm
at startup,
.Nm rc.shutdown
at shutdown,
and as necessary during system operation to stop, start, restart, reload,
(etc) the service.
.Ss Operation of rc
.Bl -enum
.It
Source
.Pa /etc/rc.subr
to load various shell functions to use.
.It
If autobooting, set
.Dv $autoboot
to
.Sq yes ,
and enable a flag which prevents the
.Nm rc.d
scripts from performing the check for already running processes
(thus speeding up the boot process).
This speedup won't occur when
.Nm
is started up after exiting the single-user shell.
.It
Invoke
.Xr rcorder 8
to order the files in
.Pa /etc/rc.d/
that do not have a
.Dq nostart
keyword (refer to
.Xr rcorder 8 's
.Fl s
flag),
and assigns the result to a variable.
.It
Calls each script in turn using run_rc_script() (from
.Pa /etc/rc.subr ) ,
which sets
.Dv $1
to
.Sq start ,
and sources the script in a subshell.
If the script has a
.Sq .sh
suffix then it is sourced directly into the current shell.
.El
.Ss Operation of rc.shutdown
.Bl -enum
.It
Source
.Pa /etc/rc.subr
to load various shell functions to use.
.It
Invoke
.Xr rcorder 8
to order the files in
.Pa /etc/rc.d/
that have a
.Dq shutdown
keyword (refer to
.Xr rcorder 8 's
.Fl k
flag),
reverses that order, and assigns the result to a variable.
.It
Calls each script in turn using run_rc_script() (from
.Pa /etc/rc.subr ) ,
which sets
.Dv $1
to
.Sq stop ,
and sources the script in a subshell.
If the script has a
.Sq .sh
suffix then it is sourced directly into the current shell.
.El
.Ss Contents of rc.d/
.Nm rc.d/
is located in
.Pa /etc/rc.d .
The following file naming conventions are currently used in
.Nm rc.d/ :
.Bl -tag -width ALLUPPERCASE -offset indent
.It ALLUPPERCASE
Scripts that are
.Sq placeholders
to ensure that certain operations are done before others.
In order of startup, these are:
.Bl -tag -width NETWORKING
.It NETWORKING
Ensure basic network services are running, including general
network configuration
.Pq Pa network
and
.Pa dhclient .
.It SERVERS
Ensure basic services (such as
.Pa NETWORKING ,
.Pa ppp ,
.Pa syslogd ,
and
.Pa kdc )
exist for services that start early (such as
.Pa named ) ,
because they're required by
.Pa DAEMON
below.
.It DAEMON
Before all general purpose daemons such as
.Pa dhcpd ,
.Pa lpd ,
and
.Pa ntpd .
.It LOGIN
Before user login services
.Pa ( inetd ,
.Pa telnetd ,
.Pa rshd ,
.Pa sshd ,
and
.Pa xdm ) ,
as well as before services which might run commands as users
.Pa ( cron ,
.Pa postfix ,
and
.Pa sendmail ) .
.El
.It foo.sh
Scripts that are to be sourced into the current shell rather than a subshell.
Extreme care must be taken in using this, as the startup sequence will
terminate if the script does.
.Pa /etc/rc.d/bootconf.sh
uses this behaviour to allow the user to select a different
configuration (including
.Pa /etc/rc.conf )
early in the boot.
.It bar
Scripts that are sourced in a subshell.
These can stop the boot if necessary with the following shell
commands:
.Bd -literal -offset
	if [ "$autoboot" = yes ]; then
		kill -TERM $$
	fi
	exit 1
.Ed
.Pp
Note that this should be used sparingly!
.El
.Pp
The scripts are expected to support at least the following arguments:
.Bl -tag -width restart -offset indent
.It start
Start the service.
This should check that the service is to be started as specified by
.Xr rc.conf 5 .
Also checks if the service is already running and refuses to start if
it is.
This latter check is not performed by standard
.Nx
scripts if the system is starting directly to multi-user mode, to
speed up the boot process.
If
.Sq forcestart
is given, ignore the rc.conf check and start anyway.
.It stop
If the service is to be started as specified by
.Xr rc.conf 5 ,
stop the service.
This should check that the service is running and complain if it's not.
If
.Sq forcestop
is given, ignore the rc.conf check and attempt to stop.
.It restart
Effectively perform a stop then a start.
.It status
If the script starts a process (rather than performing a one-off
operation), show the status of the process.
Otherwise it's not necessary to support this argument.
Defaults to displaying the process ID of the program (if running).
.It rcvar
Display which
.Pa /etc/rc.conf
variables are used to control the startup of the service (if any).
.El
.Pp
Other arguments (such as
.Sq reload ,
.Sq dumpdb ,
etc) can be added if necessary.
.Pp
In order to simplify scripts, the run_rc_command() function from
.Pa /etc/rc.subr
may be used.
.Sh FILES
.Bl -tag -width /etc/rc.shutdown -compact
.It Pa /etc/rc
Startup script called by
.Xr init 8 .
.It Pa /etc/rc.d/
Directory containing control scripts for each service.
.It Pa /etc/rc.shutdown
Shutdown script called by
.Xr shutdown 8 .
.It Pa /etc/rc.subr
Contains functions used by various scripts.
.El
.Sh SEE ALSO
.Xr rc.conf 5 ,
.Xr init 8 ,
.Xr rcorder 8 ,
.Xr reboot 8 ,
.Xr shutdown 8
.Sh HISTORY
The
.Nm
command appeared in
.Bx 4.0 .
The
.Pa /etc/rc.d
support was implemented in
.Nx 1.5
by Luke Mewburn <lukem@netbsd.org>.