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rc.serial(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 com-
     mands which are pertinent only to a specific 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 exe-
     cuted at boot time and shutdown time.

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

     2.   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 exit-
	  ing the single-user shell.

     3.   Invoke rcorder(8) to order the files in /etc/rc.d/ that do not have
	  a ``nostart'' keyword (refer to rcorder(8)'s -s flag), 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 ``start'', and sources the script in a subshell.
	  If the script has a .sh suffix then it is sourced directly into the
	  current shell.

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

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

     3.   Call each script in turn using run_rc_script() (from rc.subr(8)),

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

			 NETWORKING  Ensure basic network services are run-
				     ning, including general network configu-
				     ration (network1, network2, network3).

			 SERVERS     Ensure basic services (such as
				     NETWORKING, ppp-user, syslogd, and isdnd)
				     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 subshell 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.  These can
			 stop the boot if necessary with the following shell
			 commands:

			       if [ "$autoboot" = yes ]; then
				       kill -TERM $$
			       fi
			       exit 1

			 Note that this should be used extremely sparingly!

     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() func-
     tion:

	   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
		    running).

	   poll     If the script starts a process (rather than performing a
		    one-off operation), wait for the command to exit.  Other-
		    wise 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 variable, and define their actions in a variable con-
     structed 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 shut-
	 down 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 opposite
	 would be true.

     o	 The output from each script is traditionally a space character, fol-
	 lowed 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 sin-
     gle-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 separated 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/ direc-
     tories.  The default locations are /usr/local/etc/rc.d/ and
     /usr/X11R6/etc/rc.d/, but these may be overridden with the local_startup
     rc.conf(5) variable.

     Finally, the /etc/rc.d/network_ipv6 script configures IPv6 interfaces and
     options.

     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.

EXAMPLES

     The following is a minimal rc.d/ style script.  Most scripts require lit-
     tle more than the following.

	   #!/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"

	   load_rc_config $name
	   run_rc_command "$1"

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

	   #!/bin/sh
	   #

	   # PROVIDE: 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"

     The following is a simple, hypothetical example of an old-style
     /usr/local/etc/rc.d/ script, which would start a daemon at boot time, and
     kill it at shutdown time.

	   #!/bin/sh -
	   #
	   #	initialization/shutdown script for foobar package

	   case "$1" in
	   start)
		   /usr/local/sbin/foo -d && echo -n ' foo'
		   ;;
	   stop)
		   kill `cat /var/run/foo.pid` && echo -n ' foo'
		   ;;
	   *)
		   echo "unknown option: $1 - should be 'start' or 'stop'" >&2
		   ;;
	   esac

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

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(1) results soon after the rc
				       process begins.	Useful when dmesg
				       buffer in the kernel no longer has this
				       information.

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.

FreeBSD 5.4		       November 4, 2002 		   FreeBSD 5.4

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