Manual Pages  — RC

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 services.

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. 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.

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.

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).

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.

#!/bin/sh
#

# PROVIDE: foo
# REQUIRE: bar_service_required_to_precede_foo

amp;. /etc/rc.subr

name="foo"
rcvar=foo_enable
command="/usr/local/bin/foo"

load_rc_config $name
run_rc_command "$1"

#!/bin/sh
#

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

amp;. /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.

https://docs.freebsd.org/en/articles/rc-scripting/

Practical rc.d scripting in BSD,