Now that FreeBSD includes rc.d, configuration of application startup is easier and provides more features. Using the key words discussed in Section 12.4, “Managing Services in FreeBSD”, applications can be set to start after certain other services and extra flags can be passed through /etc/rc.conf in place of hard coded flags in the start up script. A basic script may look similar to the following:

#!/bin/sh
#
# PROVIDE: utility
# REQUIRE: DAEMON
# KEYWORD: shutdown

. /etc/rc.subr

name=utility
rcvar=utility_enable

command="/usr/local/sbin/utility"

load_rc_config $name

#
# DO NOT CHANGE THESE DEFAULT VALUES HERE
# SET THEM IN THE /etc/rc.conf FILE
#
utility_enable=${utility_enable-"NO"}
pidfile=${utility_pidfile-"/var/run/utility.pid"}

run_rc_command "$1"

This script will ensure that the provided utility will be started after the DAEMON pseudo-service. It also provides a method for setting and tracking the process ID (PID).

This application could then have the following line placed in /etc/rc.conf:

utility_enable="YES"

This method allows for easier manipulation of command line arguments, inclusion of the default functions provided in /etc/rc.subr, compatibility with rcorder(8), and provides for easier configuration via rc.conf.

Other services can be started using inetd(8). Working with inetd(8) and its configuration is described in depth in Section 29.2, “The inetd Super-Server”.

In some cases, it may make more sense to use cron(8) to start system services. This approach has a number of advantages as cron(8) runs these processes as the owner of the crontab(5). This allows regular users to start and maintain their own applications.

The @reboot feature of cron(8), may be used in place of the time specification. This causes the job to run when cron(8) is started, normally during system initialization.