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RC(8)				   BSD System Manager's Manual				    RC(8)

NAME
     rc -- command scripts for auto-reboot and daemon startup

SYNOPSIS
     rc
     rc.conf
     rc.conf.local
     rc.d/
     rc.firewall
     rc.local
     rc.shutdown
     rc.subr

DESCRIPTION
     The rc utility is the command script which controls the automatic boot process after being
     called by init(8).  The rc.local script contains commands which are pertinent only to a spe-
     cific site.  Typically, the /usr/local/etc/rc.d/ mechanism is used instead of rc.local these
     days but if you want to use rc.local, it is still supported.  In this case, it should source
     /etc/rc.conf and contain additional custom startup code for your system.  The best way to
     handle rc.local, however, is to separate it out into rc.d/ style scripts and place them
     under /usr/local/etc/rc.d/.  The rc.conf file contains the global system configuration
     information referenced by the startup scripts, while rc.conf.local contains the local system
     configuration.  See rc.conf(5) for more information.

     The rc.d/ directories contain scripts which will be automatically executed at boot time and
     shutdown time.

   Operation of rc
     1.   If autobooting, set autoboot=yes and enable a flag (rc_fast=yes), which prevents the
	  rc.d/ scripts from performing the check for already running processes (thus speeding up
	  the boot process).  This rc_fast=yes speedup will not occur when rc is started up after
	  exiting the single-user shell.

     2.   Determine whether the system is booting diskless, and if so run the
	  /etc/rc.initdiskless script.

     3.   Source /etc/rc.subr to load various rc.subr(8) shell functions to use.

     4.   Load the configuration files.

     5.   Determine if booting in a jail, and add ``nojail'' to the list of KEYWORDS to skip in
	  rcorder(8).

     6.   Invoke rcorder(8) to order the files in /etc/rc.d/ that do not have a ``nostart'' KEY-
	  WORD (refer to rcorder(8)'s -s flag).

     7.   Call each script in turn using run_rc_script() (from rc.subr(8)), which sets $1 to
	  ``start'', and sources the script in a subshell.  If the script has a .sh suffix then
	  it is sourced directly into the current shell.  Stop processing when the script that is
	  the value of the $early_late_divider has been run.

     8.   Re-run rcorder(8), this time including the scripts in the $local_startup directories.
	  Ignore everything up to the $early_late_divider, then start executing the scripts as
	  described above.

   Operation of rc.shutdown
     1.   Source /etc/rc.subr to load various rc.subr(8) shell functions to use.

     2.   Load the configuration files.

     3.   Invoke rcorder(8) to order the files in /etc/rc.d/ and the $local_startup directories
	  that have a ``shutdown'' KEYWORD (refer to rcorder(8)'s -k flag), reverse that order,
	  and assign the result to a variable.

     4.   Call each script in turn using run_rc_script() (from rc.subr(8)), which sets $1 to
	  ``stop'', and sources the script in a subshell.  If the script has a .sh suffix then it
	  is sourced directly into the current shell.

   Contents of rc.d/
     rc.d/ is located in /etc/rc.d/.  The following file naming conventions are currently used in
     rc.d/:

	   ALLUPPERCASE  Scripts that are ``placeholders'' to ensure that certain operations are
			 performed before others.  In order of startup, these are:

			 NETWORKING  Ensure basic network services are running, including general
				     network configuration.

			 SERVERS     Ensure basic services exist for services that start early
				     (such as named), because they are required by DAEMON below.

			 DAEMON      Check-point before all general purpose daemons such as lpd
				     and ntpd.

			 LOGIN	     Check-point before user login services (inetd and sshd), as
				     well as services which might run commands as users (cron and
				     sendmail).

	   foo.sh	 Scripts that are to be sourced into the current shell rather than a sub-
			 shell have a .sh suffix.  Extreme care must be taken in using this, as
			 the startup sequence will terminate if the script does.

	   bar		 Scripts that are sourced in a subshell.  The boot does not stop if such
			 a script terminates with a non-zero status, but a script can stop the
			 boot if necessary by invoking the stop_boot() function (from rc.subr(8)
			 ).

     Each script should contain rcorder(8) keywords, especially an appropriate ``PROVIDE'' entry,
     and if necessary ``REQUIRE'' and ``BEFORE'' keywords.

     Each script is expected to support at least the following arguments, which are automatically
     supported if it uses the run_rc_command() function:

	   start    Start the service.	This should check that the service is to be started as
		    specified by 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
		    FreeBSD scripts if the system is starting directly to multi-user mode, to
		    speed up the boot process.	If forcestart is given, ignore the rc.conf(5)
		    check and start anyway.

	   stop     If the service is to be started as specified by rc.conf(5), stop the service.
		    This should check that the service is running and complain if it is not.  If
		    forcestop is given, ignore the rc.conf(5) check and attempt to stop.

	   restart  Perform a stop then a start.

	   status   If the script starts a process (rather than performing a one-off operation),
		    show the status of the process.  Otherwise it is not necessary to support
		    this argument.  Defaults to displaying the process ID of the program (if run-
		    ning).

	   poll     If the script starts a process (rather than performing a one-off operation),
		    wait for the command to exit.  Otherwise it is not necessary to support this
		    argument.

	   rcvar    Display which rc.conf(5) variables are used to control the startup of the
		    service (if any).

     If a script must implement additional commands it can list them in the extra_commands vari-
     able, and define their actions in a variable constructed from the command name (see the
     EXAMPLES section).

     The following key points apply to old-style scripts in /usr/local/etc/rc.d/:

     o	 Scripts are only executed if their basename(1) matches the shell globbing pattern *.sh,
	 and they are executable.  Any other files or directories present within the directory
	 are silently ignored.

     o	 When a script is executed at boot time, it is passed the string ``start'' as its first
	 and only argument.  At shutdown time, it is passed the string ``stop'' as its first and
	 only argument.  All rc.d/ scripts are expected to handle these arguments appropriately.
	 If no action needs to be taken at a given time (either boot time or shutdown time), the
	 script should exit successfully and without producing an error message.

     o	 The scripts within each directory are executed in lexicographical order.  If a specific
	 order is required, numbers may be used as a prefix to the existing filenames, so for
	 example 100.foo would be executed before 200.bar; without the numeric prefixes the oppo-
	 site would be true.

     o	 The output from each script is traditionally a space character, followed by the name of
	 the software package being started or shut down, without a trailing newline character
	 (see the EXAMPLES section).

SCRIPTS OF INTEREST
     When an automatic reboot is in progress, rc is invoked with the argument autoboot.  One of
     the scripts run from /etc/rc.d/ is /etc/rc.d/fsck.  This script runs fsck(8) with option -p
     and -F to ``preen'' all the disks of minor inconsistencies resulting from the last system
     shutdown.	If this fails, then checks/repairs of serious inconsistencies caused by hardware
     or software failure will be performed in the background at the end of the booting process.
     If autoboot is not set, when going from single-user to multi-user mode for example, the
     script does not do anything.

     The rc.early script is run very early in the startup process, immediately before the file
     system check.  The rc.early script is deprecated.	Any commands in this file should be sepa-
     rated out into rc.d/ style scripts and integrated into the rc system.

     The /etc/rc.d/local script can execute scripts from multiple rc.d/ directories.  The default
     location includes /usr/local/etc/rc.d/, but these may be overridden with the local_startup
     rc.conf(5) variable.

     The /etc/rc.d/serial script is used to set any special configurations for serial devices.

     The rc.firewall script is used to configure rules for the kernel based firewall service.  It
     has several possible options:

	   open      will allow anyone in
	   client    will try to protect just this machine
	   simple    will try to protect a whole network
	   closed    totally disables IP services except via lo0 interface
	   UNKNOWN   disables the loading of firewall rules
	   filename  will load the rules in the given filename (full path required).

     The /etc/rc.d/atm* scripts are used to configure ATM network interfaces.  The interfaces are
     configured in three passes.  The first pass performs the initial interface configuration.
     The second pass completes the interface configuration and defines PVCs and permanent ATMARP
     entries.  The third pass starts any ATM daemons.

     Most daemons, including network related daemons, have their own script in /etc/rc.d/, which
     can be used to start, stop, and check the status of the service.

     Any architecture specific scripts, such as /etc/rc.d/apm for example, specifically check
     that they are on that architecture before starting the daemon.

     Following tradition, all startup files reside in /etc.

FILES
     /etc/rc
     /etc/rc.conf
     /etc/rc.conf.local
     /etc/rc.d/
     /etc/rc.firewall
     /etc/rc.local
     /etc/rc.shutdown
     /etc/rc.subr
     /var/run/dmesg.boot	       dmesg(8) results soon after the rc process begins.  Useful
				       when dmesg(8) buffer in the kernel no longer has this
				       information.

EXAMPLES
     The following is a minimal rc.d/ style script.  Most scripts require little more than the
     following.

	   #!/bin/sh
	   #

	   # PROVIDE: foo
	   # REQUIRE: bar_service_required_to_precede_foo

	   . /etc/rc.subr

	   name="foo"
	   rcvar=`set_rcvar`
	   command="/usr/local/bin/foo"

	   load_rc_config $name
	   run_rc_command "$1"

     Certain scripts may want to provide enhanced functionality.  The user may access this func-
     tionality through additional commands.  The script may list and define as many commands at
     it needs.

	   #!/bin/sh
	   #

	   # PROVIDE: foo
	   # REQUIRE: bar_service_required_to_precede_foo
	   # BEFORE:  baz_service_requiring_foo_to_precede_it

	   . /etc/rc.subr

	   name="foo"
	   rcvar=`set_rcvar`
	   command="/usr/local/bin/foo"
	   extra_commands="nop hello"
	   hello_cmd="echo Hello World."
	   nop_cmd="do_nop"

	   do_nop()
	   {
		   echo "I do nothing."
	   }

	   load_rc_config $name
	   run_rc_command "$1"

     As all processes are killed by init(8) at shutdown, the explicit kill(1) is unnecessary, but
     is often included.

SEE ALSO
     kill(1), rc.conf(5), init(8), rcorder(8), rc.subr(8), reboot(8), savecore(8)

HISTORY
     The rc utility appeared in 4.0BSD.

BSD					   May 18, 2007 				      BSD
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