Photon

Start Photon server

Syntax:

Photon [-b color] [-C pixels] [-D time] [-g] 
       [-l command] [-m timers] [-N name] [-n clients] 
       [-q] [-R time] [-r regions] [-s] [-t tiles]
       [-T pixels] [-U pixels] [-v]

Runs on:

Neutrino

Options:

-b color

Background color (hex RGB value).

-C pixels

Specify the mouse multi-click threshold. This option affects only multi-clicks and takes effect when the supplied value is larger than the specified -T value. This option is useful for touch screens. Default is 0 pixels.

-D time

Set the mouse repeat delay in milliseconds (default is 500). This is the amount of time before mouse repeat events ( Ph_EV_BUT_REPEAT) are generated.

-g

Don't create a new process group.

-l command

(“el”) A command that's to be executed at login.

-m timers

Set the total number of timers that the Photon Server can support. If you specify the -r option, the default is 4 times the number of regions.

-N name

Specify the name to register.

-n clients

Set the maximum number of clients that can communicate with the Photon Server (default is no limit).

-q

Be quiet.

-R time

Set the mouse repeat rate in milliseconds (default is 33). This is the amount of time between mouse repeat events ( Ph_EV_BUT_REPEAT).

-r regions

Set the maximum number of regions that the Photon Server can support. Default is no limit.

-s

Create a new Photon session.

-t tiles

Set the total number of tiles that the Photon Server can support. This number includes the complete rectangle set for each active event in the event space. If you specify the -r option, the default is 12 times the number of regions. Otherwise, the default is an unlimited number of tiles.

-T pixels

Specify the mouse click threshold for drag initiation and multi clicking. Default is 5 pixels.

-U pixels

Specify the size of the area where the position of the release is forced to be the same position of the press. This may be used to prevent random changes in position because the size of a finger press is larger than a pixel. Default is 0 pixels.

-v

Be verbose.

Description:

The Photon server lets applications open regions from which Photon events may be emitted and collected. Specifying the number of clients, regions, and rectangles limits the resources available to the Photon server.

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This utility needs to have the setuid (“set user ID”) bit set in its permissions. If you use mkefs, mketfs, or mkifs on a Windows host to include this utility in an image, use the perms attribute to specify its permissions explicitly, and the uid and gid attributes to set the ownership correctly.

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The Photon device is owned by and has the permissions associated with the user who invoked it.

To connect with a Photon device, a user must have read permission on the device. To emit events or to create a region, the user must also have write permission.

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The Photon Server registers the name of /dev/photon by default. If the PHOTON environment variable is defined, that name is be registered instead.

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Examples:

Start the Photon server, configuring it for 5 clients that can open a maximum of 200 regions along with up to 1000 rectangles:

Photon -n 5 -r 200 -t 1000

Environment variables:

PHOTON

The name of the photon device (defaults to /dev/photon).