command scripts for system startup
is the command script that is invoked by
system starts up. It performs system housekeeping chores and starts up system
daemons. Additionally, rc
is intricately tied to
script, which runs commands and daemons pertaining to the network.
is also used to execute any
scripts hold commands which are
pertinent only to a specific site.
All of these startup scripts are controlled to some extent by variables defined
which specify which daemons and services to run.
, it sets the process priority, umask, and
resource limits according to the “daemon” login class as
It then starts rc
and attempts to execute the
sequence of commands therein.
The first part of rc
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
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
configuration variables, mounts filesystems, saves
the file /var/run/dmesg.boot
, starts system
daemons, preserves editor files, clears the scratch directory
, and saves any possible core image that
might have been generated as a result of a system crash, with
If at any point the boot script fails,
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
to start daemons that must be run before the
security level changes. Following this, rc
sets the security level to '1' if it wasn't set already by
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
(it is not the very last as there are a few
services that must be started at the very end). Normally,
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
- 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
- copy of
dmesg(8) saved by
rc at boot time
command appeared in