devices hot plugging monitor
hotplugd daemon monitors the
hotplug(4) pseudo-device, acting on signaled events by executing the
scripts in the /etc/hotplug directory. By default it
uses the /dev/hotplug device for reading events
from, but an alternative device can be specified with the
Actions can be configured either for device attachment or
detachment. On device attachment the attach script
is executed if it exists. On device detachment the
detach script is executed if it exists. In both
cases two parameters are passed to the scripts: the class and name of the
attached or detached device. The device class corresponds to the classes
described in the
<sys/device.h> header file
and can be one of the following:
- generic, no special info
- CPU (carries resource utilization)
- disk drive
- network interface
- tape device
- serial line interface
Not all classes are really usable. For example, it's unlikely that a CPU will be hotplugged.
The device name is the usual name, as listed in MAKEDEV(8), and the unit number, e.g. sd1.
- Pseudo-device file.
- Directory where the scripts to execute are located.
- Script to execute on device attachment.
- Script to execute on device detachment.
Sample attach script:
#!/bin/sh DEVCLASS=$1 DEVNAME=$2 case $DEVCLASS in 2) # disk devices disklabel=`/sbin/disklabel $DEVNAME 2>&1 | \ sed -n '/^label: /s/^label: //p'` case $disklabel in Sony*DSC*) # Sony DSC camera mount -o nodev,nosuid /dev/"$DEVNAME"i /mnt/camera ;; esac ;; 3) # network devices; requires hostname.$DEVNAME sh /etc/netstart $DEVNAME ;; esac
hotplugd program first appeared in
hotplugd program was written by