RC(8) BSD 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.shutdown.local
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 and
rc.shutdown.local scripts contains commands which are pertinent only to a
specific site. Typically, scripts in /usr/local/etc/rc.d/ is used
instead of rc.local and rc.shutdown.local these days but if you want to
use them it is still supported. In this case, they should source
/etc/rc.conf and contain additional custom startup and shutdown code for
your system. The best way to handle rc.local and rc.shutdown.local, how‐
ever, is to separate them 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 exe‐
cuted at boot time and shutdown time.
Operation of rc
1. Source /etc/rc.subr to load various rc.subr(8) shell functions to
use.
2. 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 exit‐
ing the single-user shell.
3. 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), 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 “start”, and sources the script in a subshell. If
the script has a .sh suffix then it is sourced directly into the
current shell.
Operation of rc.shutdown
1. Source /etc/rc.subr to load various rc.subr(8) shell functions to
use.
2. Invoke rcorder(8) to order the files in /etc/rc.d/ that have a
“shutdown” keyword (refer to rcorder(8)'s -k flag), reverse that
order, and assign the result to a variable.
3. Call each script in turn using run_rc_script() (from rc.subr(8)),
which sets $1 to “stop”, and sources the script in a subshell. If
the script has a .sh suffix then it is sourced directly into the
current shell.
Contents of rc.d/
rc.d/ is located in /etc/rc.d/. The following file naming conventions
are currently used in rc.d/:
ALLUPPERCASE Scripts that are “placeholders” to ensure that cer‐
tain operations are performed before others. In
order of startup, these are:
NETWORKING Ensure basic network services are run‐
ning, including general network configu‐
ration (netif, routing, network_ipv6,
isdnd, ppp-user).
SERVERS Ensure basic services (such as NETWORKING
and syslogd) exist for services that
start early (such as named), because they
are required by DAEMON below.
DAEMON Check-point before all general purpose
daemons such as dhcpd, ftpd and lpd.
LOGIN Check-point before user login services
(inetd and sshd), as well as services
which might run commands as users (cron,
jail and sendmail).
foo.sh Scripts that are to be sourced into the current shell
rather than a subshell have a .sh suffix. Extreme
care must be taken in using this, as the startup
sequence will terminate if the script does.
bar Scripts that are sourced in a subshell. These can
stop the boot if necessary with the following shell
commands:
if [ "$autoboot" = yes ]; then
kill -TERM $$
fi
exit 1
Note that this should be used extremely sparingly!
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() func‐
tion:
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
DragonFly scripts if the system is starting directly to
multi-user mode, to speed up the boot process. If
faststart is given, skip the PID check. 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. Oth‐
erwise it is not necessary to support this argument.
Defaults to displaying the process ID of the program (if
running).
poll If the script starts a process (rather than performing a
one-off operation), wait for the command to exit. Other‐
wise it is not necessary to support this argument.
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 con‐
structed 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 only argument. At shutdown time, it is passed the
string “stop” as its 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, 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 to “preen” all UFS(5) file sys‐
tems of minor inconsistencies resulting from the last system shutdown.
If preening fails further action depends on the rc.conf(5) variable
fsck_y_enable: if the value is “NO” (default) rc exits, if value is
“YES”, fsck(8) is run with option -y, if this also fails rc exits. 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/localdaemons script can execute scripts from multiple rc.d/
directories. The default locations are /usr/pkg/etc/rc.d/,
/usr/local/etc/rc.d/, /usr/pkg/xorg/etc/rc.d/ and /usr/X11R6/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 /etc/rc.d/{net*,routing} scripts are used to start the network. The
network is started in several passes. The first pass, /etc/rc.d/netif,
configures the network interfaces. The /etc/rc.d/routing script starts
routing and sets routing options. The /etc/rc.d/netoptions script sets
additional networking options. Finally, the /etc/rc.d/network_ipv6
script configures IPv6 interfaces and options.
The rc.firewall script is used to configure rules for the ipfw(4) 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.
FILES
/etc/rc
/etc/rc.conf
/etc/rc.conf.local
/etc/rc.d/
/etc/rc.firewall
/etc/rc.local
/etc/rc.shutdown
/etc/rc.shutdown.local
/etc/rc.subr
EXAMPLES
The following is a minimal rc.d/ style script. Most scripts require lit‐
tle more than the following.
#!/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=`set_rcvar`
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=`set_rcvar`
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"
The following is a simple, hypothetical example of an old-style
/usr/local/etc/rc.d/ script, which would start a daemon at boot time, and
kill it at shutdown time.
#!/bin/sh -
#
# initialization/shutdown script for foobar package
case "$1" in
start)
/usr/local/sbin/foo -d && echo -n ' foo'
;;
stop)
kill `cat /var/run/foo.pid` && echo -n ' foo'
;;
*)
echo "unknown option: $1 - should be 'start' or 'stop'" >&2
;;
esac
As all processes are killed by init(8) at shutdown, the explicit kill(1)
is unnecessary, but is often included.
SEE ALSOkill(1), ipfw(4), rc.conf(5), init(8), rcorder(8), rcrun(8), rc.subr(8),
reboot(8), savecore(8)HISTORY
The rc utility appeared in 4.0BSD. The rc.d/ facility was implemented in
NetBSD 1.5 and appeared in DragonFly 1.0.
BSD September 28, 2009 BSD