rc,
rc.firsttime,
rc.local,
rc.securelevel —
command scripts for system startup
rc is the command script that is invoked by
init(8) when the system starts up.
It performs system housekeeping chores and starts up system daemons.
Additionally,
rc is intricately tied to the
netstart(8) script, which runs
commands and daemons pertaining to the network.
rc is also used to execute any
rc.d(8) scripts defined in
rc.conf.local(8). The
rc.securelevel,
rc.firsttime, and
rc.local scripts hold commands which are
pertinent only to a specific site.
All of these startup scripts are controlled to some extent by variables defined
in
rc.conf(8), which specify
which daemons and services to run.
Before
init(8) starts
rc, it sets the process priority, umask, and
resource limits according to the “daemon” login class as
described in
login.conf(5).
It then starts
rc and attempts to execute the
sequence of commands therein.
The first part of
rc runs an
fsck(8) with option
-p to “preen” all disks of minor
inconsistencies resulting from the last system shutdown and to check for
serious inconsistencies caused by hardware or software failure. If this
auto-check and repair succeeds, then the second part of
rc is run. However, if the file
/fastboot exists, fsck will not be invoked. The
file is then removed so that fsck will be run on subsequent boots.
The second part of
rc then asks
rc.conf(8) for configuration
variables, mounts filesystems, saves
dmesg(8) output to the file
/var/run/dmesg.boot, starts system daemons,
preserves editor files, clears the scratch directory
/tmp, uses
savecore(8) to save any
possible core image that might have been generated as a result of a system
crash, and relinks kernel objects in a random order.
If at any point the boot script fails,
init(8) enters single-user mode,
allowing the superuser a shell on the console. On exiting this mode, init
again invokes
rc, but this time without
performing the file system preen.
Before
rc starts most system daemons,
netstart(8) is executed.
rc.securelevel is executed by
rc to start daemons that must be run before the
security level changes. Following this,
rc then
sets the security level to '1' if it wasn't set already by
rc.securelevel. See
securelevel(7) for the
effects of setting the security level.
If
rc.firsttime exists, it is executed once and
then deleted. Any output is mailed to root.
rc.local is executed towards the end of
rc (it is not the very last as there are a few
services that must be started at the very end). Normally,
rc.local contains commands and daemons that are
not part of the stock installation.
- /etc/netstart
- Command script for network startup.
- /etc/rc
- Command scripts for system startup.
- /etc/rc.conf
- System daemon configuration database.
- /etc/rc.conf.local
- Site specific daemon configuration database.
- /etc/rc.d
- Directory to hold
rc.d(8) scripts.
- /etc/rc.d/rc.subr
- Functions used by the
rc.d(8) scripts.
- /etc/rc.firsttime
- Commands run on the first boot after creation.
- /etc/rc.local
- Site specific command scripts for system startup.
- /etc/rc.securelevel
- Commands run before the security level changes.
- /etc/rc.shutdown
- Commands run at system shutdown.
- /fastboot
- Tells rc not to run
fsck(8) during the next
boot.
- /var/run/dmesg.boot
- Copy of
dmesg(8) saved by
rc at boot time.
sysctl.conf(5),
securelevel(7),
init(8),
netstart(8),
rc.conf(8),
rc.d(8),
rc.shutdown(8),
rcctl(8)
The
rc command appeared in
4.0BSD.
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