bbenne10 / rc

minimalistic init script

rc - simple BSD-ish init system

The script rc is a minimalistic init script made for use with sinit. It picks up where sinit leaves off, which is to say it sets the hostname, starts udev, starts some daemons (though doesn't ensure they stay running) and

Later, in the user space, you can use it to list currently running daemons and individually start or stop them.

It was developed for arch linux to get rid of systemd's init, but it can probably run on other distributions as well.

Installing

Dependencies:

• sinit
• ubase (for killall5 implementation)
• optionally eudev or systemd (for udev)

sinit and ubase are downloaded, built and installed into sane places upon running setup.sh.

Procedure

• Read setup.sh. Really.
• ROOT=test ./setup.sh
• Check test/ to make sure everything looks okay.
• sudo ./setup.sh (and follow its instructions)
• Check and edit /etc/rc.conf
• Reboot

See sections "Managing Services" and "Further configuration".

Shutdown & Reboot

Three commands are installed with setup.sh: shutdown, poweroff, and reboot.

• shutdown calls reboot and poweroff, so if they're right shutdown will work fine.
• poweroff calls rc shutdown, which calls sinit's version halt with the -p flag.
• reboot calls rc reboot, which ultimately calls sinit's halt with -r

You may also signal sinit directly to perform these actions, but that is outside rc's scope.

Managing services

A service is defined as any file present in /etc/rc.d/. Any of these services may be enabled by adding their name to the space-separated list called ENABLED in /etc/rc.conf. The name may be prefixed with '@' to start that service in the background.

Starting and stopping a service are simple:

sudo rc start dbus
sudo rc stop dbus

Polling services is equally simple:

rc list

You may manually trigger shutdown, reboot or suspend with:

sudo rc shutdown
sudo rc reboot
sudo rc suspend

Note: rc suspend does nothing more than echo "mem" > /sys/power/state. If your machine requires more hand-holding here (unloading modules etc), you're currently on your own. I am open to pull requests that address this in a general way though.

Writing services

Services are intentionally simple. They simply export four functions that map to the four main functions one may perform on a service. They export:

1. start: Which serves to get the service into a running state
2. stop: Which serves to stop the service
3. restart: Which serves to restart the service (and often will just call start and stop)
4. poll: Which determines if the service is currently running

start, stop, restart do not have a defined return value. poll should return 0 if the service is currently running, and 1 in the case that it is not.

Further configuration

udev

You need to decide what to use to set up the devices and load the modules. rc supports systemd's udev and eudev by default. You can change the udev system by changing the value of the UDEV variable in rc.conf

rc supports both eudev and systemd's udev implementations as eudev and systemd respectively.

minirc, from which rc forked, supports busybox's mdev implementation. This was dropped from rc due to lack of interest from the developers.

Local startup script

rc will run /etc/rc.local on boot if the file exists and has the executable bit set. This allows the user to run commands in addition to the basic startup that rc provides. This is a good place to load modules if udev does not detect that they should be loaded on boot or to set the backlight to a reasonable level, for instance.

Usage of the user space program

Run rc --help for information. Never run rc init except during the boot process, when called by sinit.

About

rc is a fork of minirc.

minirc is, at the time of forking, written by Roman Zimbelmann and Sam Stuewe and is available under the GPL v2 license.

Parts of the function on_boot() and the start/stop function of iptables were taken from archlinux initscripts (http://www.archlinux.org). minirc's authors were unable to determine the author or authors of those parts. I have made no such attempt to find the authors.

For information on rc's license, please see LICENSE in the source repository.