RC(8) BSD System Manager's Manual RC(8)
rc -- command scripts for auto-reboot and daemon startup
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 spe-
cific 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
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
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'' to the list of KEYWORDS to skip in
6. Invoke rcorder(8) to order the files in /etc/rc.d/ that do not have a ``nostart'' KEY-
WORD (refer to rcorder(8)'s -s flag).
7. 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.
8. 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
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
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
SERVERS Ensure basic services 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
LOGIN Check-point before user login services (inetd and sshd), as
well as services which might run commands as users (cron and
foo.sh Scripts that are to be sourced into the current shell rather than a sub-
shell 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 run-
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
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 vari-
able, and define their actions in a variable constructed from the command name (see the
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 shutdown 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 oppo-
site would be true.
o 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 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 sepa-
rated 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/ directories. The default
location includes /usr/local/etc/rc.d/, but these may be overridden with the local_startup
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).
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.
/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
The following is a minimal rc.d/ style script. Most scripts require little more than the
# PROVIDE: foo
# REQUIRE: bar_service_required_to_precede_foo
Certain scripts may want to provide enhanced functionality. The user may access this func-
tionality through additional commands. The script may list and define as many commands at
# PROVIDE: foo
# REQUIRE: bar_service_required_to_precede_foo
# BEFORE: baz_service_requiring_foo_to_precede_it
hello_cmd="echo Hello World."
echo "I do nothing."
As all processes are killed by init(8) at shutdown, the explicit kill(1) is unnecessary, but
is often included.
kill(1), rc.conf(5), init(8), rcorder(8), rc.subr(8), reboot(8), savecore(8)
The rc utility appeared in 4.0BSD.
BSD May 18, 2007 BSD