jsmond

deactivate screensaver on joystick activity

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Manual section:	1
Manual group:	Urchlay
Date:	2020-05-19
Version:	0.2.0

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SYNOPSIS

DESCRIPTION

jsmond lets you play games with your joysticks/gamepads without the screen -saver activating due to lack of keyboard/mouse input. It can also prevent -the screensaver from activating when a fullscreen window is in use (e.g. -while watching a movie).

Multiple joystick devices can be monitored. By default, jsmond -monitors up to 16 devices, named /dev/input/js0 through js15. -These devices don't have to actually exist: they can come and go -as joysticks are plugged in and unplugged.

Every interval milliseconds (250, or whatever -i is set to), jsmond -checks to see if there's been any activity on any of the devices it's -monitoring. If so, it sends a fake mouse movement, keystroke, or mouse -button click, which the screen saver will see as activity.

It's recommended to let jsmond find the joysticks itself. However, -you can pass one or more device names (or just numbers) if the default -doesn't do the right thing for you. In this case, only these devices -will be monitored (no search is done).

jsmond should be started from your .xinitrc or whatever X startup -script your window manager or desktop environment uses. By default, it -will exit when the X server does. There's no PID file: use "pkill jsmond" -if you need to kill the daemon.

OPTIONS

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-`--help`	Print usage summary
-`-i <interval>`	Interval to check for activity. Can be given in seconds -with s suffix (e.g. 1s), or milliseconds with m -(e.g. 200m). If just a number is given, it's assumed -to be in seconds if it's under 100, otherwise it's treated -as milliseconds. Default: 250m.
-`-k <keycode>`	Send this keycode when activity is detected. Default -is to search the keymap for an unused code. If you set this -manually, it should be a keycode that doesn't map to a keysym -in your usual keymapping (use "xmodmap -pk" to find one).
-`-b <button>`	Send a click of this button when activity is detected, -rather than a keystroke. Should be a button that -applications don't normally respond to (6 or higher), -but in some environments, the window manager responds to -all the 'extra' buttons as though they were button 1.
-`-m`	Send mouse movements rather than a keystroke. This will -move the pointer 10 pixels to the right and down, then -10 pixels to the left and up, then warp the pointer back -to its starting point.
-`-c <command>`	Run a command when activity is detected, rather than -sending a fake keystroke/click/motion. It's recommended -to set interval to at least 1 second when using this -option, to avoid excess process-spawning overhead.
-`-x`	Same as -c "xscreensaver-command -deactivate" -i 1s.
-`-f`	Deactivate screensaver if a fullscreen window is detected. -This isn't likely to be 100% reliable yet.
-`-F`	Same as -f, but also disables joystick monitoring entirely. -Note that -j, -d, and joydev are ignored -with this option.

These options are intended for developers and really shouldn't be -needed for normal use:

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-`-d <dir>`	Path to the directory containing joystick device nodes. -Default is "/dev/input". This directory is monitored with -inotify(7) so jsmond will be aware of hotplug events.
-`-j <name>`	Name of joystick device nodes, without any numeric -suffix. Default is "js".
-`-D`	Debug mode: run in foreground and print verbose messages.

A space is required between an option and its argument, as shown -above. Use e.g. -i 300, not -i300.

NOTES

jsmond was tested with xlock(1) and xscreensaver(1). All 3 modes -(keycode, mouse click, and mouse motion) work with xscreensaver. -xlock doesn't respond to mouse motion, so use the keycode or click -modes with it.

jsmond can monitor up to MAX_STICKS joysticks. This is a compile time -constant, normally set to 16. See the --help output to find out -the compiled-in default.

joydev arguments can be either a path to a device node (e.g. -/dev/input/js0 or similar), or a number, which will have the default -device basename prepended to it. This is normally "/dev/input/js", but -can be changed via the -d and -j options. Note that (currently) -all the joystick devices have to be in the same directory for jsmond -to detect hotplug events!

Note that it's not an error to give nonexistent joystick device names. -jsmond will wait for devices to come into existence (e.g. as created -by udev).

If the screensaver is configured to lock the screen, and it has already -done so, pressing a joystick button/direction will just bring up the -password dialog, same as pressing a key or mouse button would.

jsmond depends on the XTest extension being present in the X server. If -you get a "X server doesn't support XTest extension" error, see your X -server documentation to find out how to enable XTest.

The fullscreen window monitoring has only been tested on a system with -a single monitor, and may not work properly in multi-head environments.

EXIT STATUS

Without the -D option, the exit status is 0 (success) if jsmond -successfully forked into the background.

A non-zero exit status means an error in the command line arguments, -or else fork() failed. No daemon will be running in this case.

With the -D option, jsmond never exits until it's killed.

BUGS

There's no way to distinguish between an invalid device name and a -device name that doesn't happen to exist yet because its device hasn't -been plugged in yet. Try to avoid typos, if you really have to use device -names (better to autodetect).

Normally once daemonized, jsmond is very robust. However, if something -does go wrong, there's no way to find out what. Probably there should -be a log file, or use syslog (or is that overkill?).

It should be (but currently isn't) possible to at least work in -mouse-motion mode even without the XTest extension, via XWarpPointer().

jsmond isn't portable. It only works on Linux, at least for now, for -three reasons:

It uses the Linux joystick API.
It uses inotify(7) to detect joystick hotplug events.
I haven't even looked at other OSes to see if it would be possible -to port the code.

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LICENSE

jsmond is released under the WTFPL: Do WTF you want with this.

AUTHOR

jsmond was written by B. Watson <yalhcru@gmail.com>.