Archive for January, 2015

Starting A Daemon via daemon(8) in FreeBSD

January 27, 2015 1 comment

Starting A Daemon via daemon(8) in FreeBSD

Daemonizing an application that must persist across reboots while including native process management capability is easily accomplished by combining the functions of rc(8) scripts and commands with daemon(8), a utility that detaches itself from the controlling terminal and executing a program. For example, a service written in Python implementing an HTTP API front-end.

Combing these two utilities enables automated process initialization during system boot and provides the ability to stop, start, and restart services manually using either the rc(8) script or service(8). For example:

/usr/local/etc/rc.d/httpapi start


service httpapi start

Create an rc(8) script in /usr/local/etc/rc.d with a name descriptive of the application. httpapi is a descriptive name in this case. Writing the rc(8) script is covered extensively well in the “Practical rc.d scripting in BSD” article on and is a very good read. Those reading this blog are encouraged to go read that article though, for expediency, a basic implementation may look very similar to:



. /etc/rc.subr

start_cmd=”/usr/sbin/daemon -u $httpapi_user $command”

load_rc_config $name
run_rc_command “$1”

The value of the key rcvar is used to automate the startup of the daemon at system boot within /etc/rc.conf. Append a line to the file containing a combination of this value as key a key with a boolean “YES” or “NO” similarly to:

echo "httpapi_enable=\"YES\"" >> /etc/rc.conf


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Categories: FreeBSD