home | help
RC(8)			     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  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 ref-
     erenced by the startup scripts, while rc.conf.local contains the local sys-
     tem 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.

     The sysrc(8) command provides a scripting interface to modify system config
     files.

   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" (no jails allowed) or
	  "nojailvnet" (only allow vnet-enabled jails) to the list  of	KEYWORDS
	  to skip in rcorder(8).

     6.   If  the  file ${firstboot_sentinel} does not exist, add "firstboot" to
	  the list of KEYWORDS to skip in rcorder(8).

     7.   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).

     8.   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 cur-
	  rent shell.  Stop processing when the script that is the value of  the
	  $early_late_divider has been run.

     9.   Check  again	to see if the file ${firstboot_sentinel} exists (in case
	  it is located on a newly mounted file system) and adjust the	list  of
	  KEYWORDs to skip appropriately.

     10.  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.

     11.  If the file ${firstboot_sentinel} exists,  delete  it.   If  the  file
	  ${firstboot_sentinel}-reboot	also exists (because it was created by a
	  script), then delete it and reboot.

   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	nisdomain),  be-
				     cause they are required by DAEMON below.

			 DAEMON      Check-point before all general purpose dae-
				     mons 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.  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.   Other-
		    wise it is not necessary to support this argument.	Defaults
		    to displaying the process ID of the program (if running).

	   describe
		    Print a short description of what the script does.

	   extracommands
		    Print the script's non-standard commands.

	   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.

	   enabled  Return 0 if the service is enabled and 1 if it is not.  This
		    command does not print anything.

	   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 constructed
     from the command name (see the "EXAMPLES" section).

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

     *	 Scripts  are only executed if their basename(1) matches the shell glob-
	 bing pattern *.sh, and they are executable.  Any other files or  direc-
	 tories present within the directory are silently ignored.

     *	 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.

     *	 The  scripts  within each directory are executed in lexicographical or-
	 der.  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 be-
	 fore 200.bar; without the numeric prefixes the opposite would be true.

     *	 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  soft-
     ware  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 /etc/rc.d/local script can execute scripts from multiple rc.d/ directo-
     ries.  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  re-
		     quired).

     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=foo_enable
	   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
	   # REQUIRE: bar_service_required_to_precede_foo
	   # BEFORE:  baz_service_requiring_foo_to_precede_it

	   . /etc/rc.subr

	   name="foo"
	   rcvar=foo_enable
	   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),	 rc.subr(8),   rcorder(8),    reboot(8),
     savecore(8), sysrc(8)

HISTORY
     The rc utility appeared in 4.0BSD.

FreeBSD 11.2			 April 23, 2016 			   RC(8)

home | help