rc

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
     commands 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
     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
          current 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),
                                     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.  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
                    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 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
         globbing pattern *.sh, and they are executable.  Any other files or
         directories 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
         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.

     ·   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 /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).

     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.

                              September 18, 2018