FreeBSD Manual Pages
DEVD(8) FreeBSD System Manager's Manual DEVD(8) NAME devd -- Device state change daemon SYNOPSIS devd [-d] DESCRIPTION The devd daemon provides a way to have userland programs run when certain kernel events happen. The following options are accepted. -d Enable debugging messages and run in the foreground instead of becoming a daemon. IMPLEMENTATION NOTES devd is a system daemon that runs in the background all the time. When- ever a device is added to or removed from the device tree, devd will exe- cute actions specified in devd.conf(5). For example, devd might execute dhclient(8) when an ethernet adapter is added to the system and kill the dhclient(8) instance when the same adapter is removed. Another example would be for devd to use a table to locate and load via kldload(8) the proper driver for an unrecognized device that is added to the system. devd hooks into the devctl(4) device driver. This device driver has hooks into the device configuration system. When nodes are added or deleted from the tree, this device will deliver information about the event to devd. Once devd has parsed the message, it will search its action list for that kind of event and perform the action with the high- est matching value. For most mundane uses, the default handlers are ade- quate. However, for more advanced users, the power is present to tweak every aspect of what happens. devd reads /etc/devd.conf and uses that file to drive the rest of the process. While the format of this file is described in devd.conf(5) some basics are covered here. In the options section, one can define multiple directories to search for config files. All files in each of these directories are parsed. These files are intended to be installed by third party vendors that wish to hook into the devd system without modi- fying the user's other config files. SEE ALSO devctl(4), devd.conf(5) AUTHORS M. Warner Losh BUGS devd currently always runs "/etc/devd-generic $device $startstop" for all device events, regardless of what the config file says to do. FreeBSD 11.1 October 17, 2002 FreeBSD 11.1
NAME | SYNOPSIS | DESCRIPTION | IMPLEMENTATION NOTES | SEE ALSO | AUTHORS | BUGS
Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=devd&sektion=8&manpath=FreeBSD+5.0-RELEASE>