USBHIDACTION(1) OpenBSD Reference Manual USBHIDACTION(1)NAMEusbhidaction - perform actions according to USB HID controls
SYNOPSISusbhidaction [-div] -c config-file -f device arg ...
DESCRIPTIONusbhidaction can be used to execute commands when certain values appear
on HID controls. The normal operation for this program is to read the
configuration file and then become a daemon and execute commands as the
HID items specify. If a read from the HID device fails the program dies;
this will make it die when the USB device is unplugged.
The options are as follows:
-c config-file
Specify a path name for the config file.
-d Toggle the daemon flag.
-f device
Specify a path name for the device to operate on. If device is
numeric, it is taken to be the USB HID device number. If it is a
relative path, it is taken to be the name of the device under
/dev. An absolute path is taken to be the literal device
pathname.
-i Ignore HID items in the config file that do not exist in the
device.
-v Be verbose, and do not become a daemon.
The config file will be re-read if the process gets a HUP signal.
CONFIGURATION
The configuration file has a very simple format. Each line describes an
action; if a line begins with a whitespace it is considered a
continuation of the previous line. Lines beginning with `#' are
considered as comments.
Each line has three parts: a name of a USB HID item, a value for that
item, and an action. There must be whitespace between the parts.
The item names are similar to those used by usbhidctl(1), but each part
must be prefixed by its page name.
The value is simply a numeric value. When the item reports this value
the action will be performed. If the value is `*' it will match any
value.
The action is a normal command that is executed with system(3). Before
it is executed some substitution will occur: `$n' will be replaced by the
nth argument on the command line, `$V' will be replaced by the numeric
value of the HID item, `$N' will be replaced by the name of the control,
and `$H' will be replaced by the name of the HID device.
FILES
/usr/share/misc/usb_hid_usages The HID usage table.
EXAMPLES
The following configuration file can be used to control the master volume
and muting of an azalia(4) device using the multimedia keys on a Belkin
USB keyboard.
# The volume range is 0..255. Moving 8 volume steps each keypress
# moves quickly through the volume range but still has decent
# granularity.
Consumer:Volume_Up 1
mixerctl -f $1 outputs.master=+8
Consumer:Volume_Down 1
mixerctl -f $1 outputs.master=-8
Consumer:Mute 1
mixerctl -f $1 outputs.master.mute=toggle
A sample invocation using this configuration would be
$ usbhidaction-f /dev/uhid1 -c conf /dev/mixer0
SEE ALSOusbhidctl(1), usbhid(3), uhid(4), usb(4)HISTORY
The usbhidaction command first appeared in OpenBSD 3.2.
OpenBSD 4.9 March 27, 2010 OpenBSD 4.9
