command scripts for system startup
is the command script that is invoked by
when the system starts up. It
performs system housekeeping chores and starts up system daemons.
is intricately tied to the
script, which runs commands
and daemons pertaining to the network. rc
is also used to
execute any rc.d(8)
scripts defined in
scripts hold commands which are pertinent only to a
All of these startup scripts are controlled to some extent by variables defined
, which specify which daemons
and services to run.
sets the process priority, umask, and resource limits according to the
“daemon” login class as described in
. It then starts
and attempts to execute the sequence of commands therein.
The first part of rc
with option -p
“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
is run. However, if the file
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
for configuration variables,
mounts filesystems, saves dmesg(8)
the file /var/run/dmesg.boot
, starts system daemons,
preserves editor files, clears the scratch directory /tmp
and saves any possible core image that might have been generated as a result
of a system crash, with savecore(8)
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.
starts most system daemons,
is executed by rc
daemons that must be run before the security level changes. Following this,
then sets the security level to '1' if it wasn't set
already by rc.securelevel
for the effects of
setting the security level.
exists, it is executed once and then deleted.
Any output is mailed to root.
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.
- Command script for network startup.
- Command scripts for system startup.
- System daemon configuration database.
- Site specific daemon configuration database.
- Directory to hold rc.d(8)
- Functions used by the
- Commands run on the first boot after creation.
- Site specific command scripts for system startup.
- Commands run before the security level changes.
- Commands run at system shutdown.
- Tells rc not to run
fsck(8) during the next boot.
- Copy of dmesg(8) saved by
rc at boot time.
command appeared in