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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.resume
     rc.shutdown
     rc.subr
     rc.suspend

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  service(8) command provides a convenient interface to manage rc.d ser-
     vices.

     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 (see below for reloading).

     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 run_rc_scripts() with the list of scripts to be run.

	  For each script that will call  run_rc_script()  (both  functions  are
	  from	rc.subr(8)), which sets $1 to "start", and sources the script in
	  a subshell.  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.  Call run_rc_scripts() again with the  new
	  list of scripts.  It will skip any that have already been run and exe-
	  cute the rest 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.   Set  rc_shutdown  to	the  value  of	the  first  argument  passed  to
	  rc.shutdown or to "unspecified" if no argument was passed.

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

     3.   Load the configuration files.

     4.   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.

     5.   Call	each  script  in  turn	using run_rc_script() (from rc.subr(8)),
	  which sets $1 to "faststop", and sources the script in a subshell.

   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:

			 FILESYSTEMS  Ensure  that  root and other critical file
				      systems are mounted.  This is the  default
				      $early_late_divider.

			 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
				      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).

	   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).

	   enable   Enable the service in rc.conf(5).

	   disable  Disable the service in rc.conf(5).

	   delete   Remove	the	service     from     rc.conf(5).      If
		    `service_delete_empty'	is	set	 to	  "YES",
		    /etc/rc.conf.d/$servicename  will  be deleted if empty after
		    modification.

	   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  configuration files are normally read only once at the start of a boot
     sequence; if a script needs to enable or  disable	any  other  script  that
     would  run  later in the sequence, it must send a SIGALRM to the rc process
     (identified by $RC_PID) to have it re-read the files.

     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.

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/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).

     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.resume(8),  rc.subr(8), rcorder(8), re-
     boot(8), savecore(8), service(8), sysrc(8)

     Practical rc.d scripting in BSD,  <https://docs.freebsd.org/en/articles/rc-
     scripting/>.

HISTORY
     The rc utility appeared in 4.0BSD.

FreeBSD ports 15.quarterly     September 20, 2024			   RC(8)

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