osdd

================================================================================

			    On-Screen Display Daemon

		       (c) 2010 Martin Mares <mj@ucw.cz>
	   (c) 2020--2021 Jiri Kalvoda <jirikalvoda@kam.mff.cuni.cz>

       You can use and distribute this program under the terms of GPLv2.

================================================================================


OSDD is a simple daemon whose purpose is to wait for messages sent by other
programs and display them on the screen using libxosd. Unlike other such
daemons, it handles message attributes (like colors), keeps its eye on
message timing and uses X properties to pass messages, so it works over SSH
connections with X forwarding (however, you need to use "ssh -Y" instead of
"ssh -X" with newer versions of OpenSSH).

I have developed osdd on Linux, but it should work on any recent POSIX-compliant
system equipped with libX11 and libxosd.

Please send all bug reports and suggestions to the author.

Usage
~~~~~
When you run `osdd' without any parameters, it forks and waits in the background
to serve the messages. It is convenient to invoke it from ~/.xsession, so that
it is started with your X session. It should exit properly when the session
terminates.

The simplest way of sending messages to the daemon is using the `osdc' client,
e.g., `osdc "Hello world!"'. Use multiple parameters to create a multi-line
message (however, the maximum number of lines is fixed and it can be changed
only by the `--lines' switch on daemon startup).

You can also add attributes to the message (written as command-line options):

  --color=c		Set foreground color of the message. Colors are specified
			either as #RGB, or #RRGGBB, or color names from X11 rgb.txt,
			or any other method documented in XParseColor(3).

  --outline-color=c	Set color of character outlines.

  --duration=ms		Show the message for a given number of miliseconds.

  --min-duration=ms	When another message arrives while this one is displayed,
			the duration of this message can be shortened, but not
			below this parameter.

  --percent=p		Draw a line with a percentage bar (p=0..100)

  --slider=p		Draw a line with a slider (p=0..100)

  --to=stdout		Write message to stdout instead of display.

  --log=mask		Write this message to log file. Bitmask.
	Last bit:       Write to ~/.osdd_last in machine readable form.
	Second bit:     Append to ~/.osdd_log in human readable form with RGB color.


The default values of most of these attributes can be given by command-line
options of the daemon, use `osdd --help' to get the full list.

Any value can be replaced by "-", meaning "read from standard input".


Example clients
~~~~~~~~~~~~~~~

osd-clock		Display current date and time (a shell script piping
			its output to osdc).

osd-mpc-volume		Adjust volume of the MPD music player daemon and show
			a slider with the new value.

osd-batt		A slightly more complex client written in C, showing
			the current status of laptop batteries. It can be asked
			to show status immediately or to run in background and
			croak whenever the battery is low.

osd-alsa		Adjust volume of an ALSA mixer channel. Also written in C.