General options:

Below: <n> denotes an unsigned decimal (e.g 123) or octal (e.g. 017) or hex (e.g. 0x50009) number. <c> denotes a string like "red" or "#123456".

-h, -help

print this text.

-H, -manpage

print man page.

-v, -version

prints version of xsnow.

-display name

Drop the snowflakes on the given display. Make sure the display is nearby, so you can hear them enjoy...

-vintage

Run xsnow in vintage settings.

-defaults

Do not read config file (see FILES).

-noconfig

Do not read or write config file (see FILES).

-hidemenu

Start with hidden interactive menu.

-nomenu

Do not start and show interactive menu.

-scale <n>

Apply scalefactor (default: 100).

-doublebuffer <n>

1: use double buffering; 0: do not use double buffering (default: 1). Only effective with '-root' or '-id' or '-xwininfo'.

-theme <n>

1: use xsnow theme for menu; 0: use system theme (default: 1)

-checkgtk <n>

0: Do not check gtk version before starting the user interface. 1: Check gtk version before starting the user interface. (default: 1).

-id <n>, -window-id <n>

Snow in window with id (for example from xwininfo).

-desktop

Act as if window is a desktop.

-allworkspaces <n>

0: use one desktop for snow, 1: use all desktops (default: 1).

-above

Snow above your windows. Default is to snow below your windows. NOTE: in some environments this results in an un-clickable desktop.

-xwininfo

Use a cursor to point at the window you want the snow to be fallen in.

-stopafter <n>

Stop xsnow after so many seconds.

-root

Force to paint on (virtual) root window.
Use this for xscreensaver: in ~.xscreensaver add:
xsnow -root
On some systems you need to add the flag -nomenu to disable the menu:
xsnow -root -nomenu
Probably, you want to start xscreensaver as follows:
xscreensaver -no-capture-stderr

-noisy

Write extra info about some mouse clicks, X errors etc, to stdout.

-cpuload <n>

How busy is your system with xsnow: the higher, the more load on the system (default: 100).

Snow options:

-snowflakes <n>

The higher, the more snowflakes are generated per second. Default: 100.

-blowsnow

(Default) Animate blow-off snow.

-noblowsnow

Do not animate blowing snow from trees or windows

-sc <c>

Use the given string as color for the flakes (default: snow).

-snowspeedfactor <n>

Multiply the speed of snow with this number/100 (default: 100).

-snowsize <n>

Set size of (non-vintage) snow flakes (default: 8).

-snow

(Default) Show snow.

-nosnow -nosnowflakes

Do not show snow.

-flakecountmax <n>

Maximum number of active flakes (default: 300).

-blowofffactor <n>

The higher, the more snow is generated in blow-off scenarios (default: 40).

Tree options:

-treetype <n>[,<n> ...]

Choose tree types: minimum 0, maximum 7 (default: 1,2,3,4,5,6,7,). Thanks to Carla Vermin for numbers >=3! Credits: Image by b0red on Pixabay.

-treetype all

(Default) Use all non-vintage available tree types.

-tc <c>

Use the given string as the color for the vintage tree (default: chartreuse). Works only for treetype 0.

-notrees

Do not display the trees.

-showtrees

(Default) Display the trees.

-trees <n>

Desired number of trees. Default 10.

-treefill <n>

Region in percents of the height of the window where trees grow (default: 30).

Santa options:

-showsanta

(Default) Display Santa running all over the screen.

-nosanta

Do not display Santa running all over the screen.

-showrudolph

(Default) With Rudolph.

-norudolph

No Rudolph.

-santa <n>

The minimum size of Santa is 0, the maximum size is 4. Default is 3. Thanks to Thomas Linder for the (big) Santa 2! Santa 3 is derived from Santa 2, and shows the required eight reindeer. The appearance of Santa 4 may be a surprise, thanks to Carla Vermin for this one.

-santaspeedfactor <n>

The speed Santa should not be excessive if he doesn't want to get fined. The appropriate speed for the Santa chosen will be multiplied by santaspeedfactor/100 (default: 100).

Celestial options:

-wind

(Default) It will get windy now and then.

-nowind

By default it gets windy now and then. If you prefer quiet weather specify -nowind.

-whirlfactor <n>

This sets the whirl factor, i.e. the maximum adjustment of the horizontal speed. The default value is 100.

-windtimer <n>

With -windtimer you can specify how often it gets windy. It's sort of a period in seconds, default value is 30.

-stars <n>

The number of stars (default: 20).

-meteorites

(Default) Show meteorites.

-nometeorites

Do not show meteorites.

-moon <n>

1: show moon, 0: do not show moon (default: 1).
Picture of moon thanks to Pedro Lasta on Unsplash.
https://unsplash.com/photos/wCujVcf0JDw

-moonspeed <n>

Speed of moon in pixels/minute (default: 120).

-moonsize <n>

Realtive size of moon (default: 100).

-halo <n>

1: show halo around moon, 0: do not show halo (default: 1).

-halobrightness <n>

Brightness of halo (default: 25).

Fallen snow options:

-wsnowdepth <n>

Maximum thickness of snow on top of windows (default: 30).

-ssnowdepth <n>

Maximum thickness of snow at the bottom of the screen (default: 50).

-maxontrees <n>

Maximum number of flakes on trees. Default 200.

-keepsnowonwindows

(Default) Keep snow on top of the windows.

-nokeepsnowonwindows

Do not keep snow on top of the windows.

-keepsnowonscreen

(Default) Keep snow at the bottom of the screen.

-nokeepsnowonscreen

Do not keep snow at the bottom of the screen.

-keepsnowontrees

(Default) Keep snow on trees.

-nokeepsnowontrees

Do not keep snow on trees.

-keepsnow

(Default) Have snow sticking anywhere.

-nokeepsnow

Do not have snow sticking anywhere.

-fluffy

(Default) Create fluff on fallen snow.

-nofluffy

Do not create fluff on fallen snow.

-offsetx <n>

Correction for window-manager provided x-coordinate of window. Default 4.

-offsety <n>

Correction for window-manager provided y-coordinate of window. Default 0.

-offsetw <n>

Correction for window-manager provided width of window. Default -8.

-offsets <n>

Correction for bottom coordinate of your screen. A negative value lifts the xsnow screen up. Default 0.

Birds options:

-anarchy <n>

Anarchy factor ( 0..100 default: 50).

-birdscolor <c>

Use the given string as color for the birds (default: #361A07).

-birdsonly <n>

Show only birds ( 0/1 default: 0).

-birdsspeed <n>

Speed of birds ( 0..300 default: 100).

-disweight <n>

Eagerness to keep desired distance ( 0..100 default: 20).

-focuscentre <n>

Eagerness to fly to the focus ( 0..300 default: 100).

-followneighbours <n>

Eagerness to follow neighbours ( 0..100 default: 30).

-nbirds <n>

Number of birds ( 0..400 default: 70).

-neighbours <n>

Number of neighbours to watch ( 0..20 default: 7).

-prefdistance <n>

Preferred distance to neighbours ( 0..100 default: 40).

-showbirds <n>

Show birds ( 0/1 default: 1).

-showattr <n>

Show attraction point ( 0/1 default: 0).

-followsanta <n>

Birds like Santa ( 0/1 default: 1).

-viewingdistance <n>

Viewing distance ( 0..95 default: 40).

FILES

$HOME/.xsnowrc

Settings are read from and written to this file. See flags -noconfig and -defaults how to influence this behaviour.
NOTE: the following settings are not read or written:
-above -defaults -desktop -fullscreen -noconfig -id
-nomenu -stopafter -xwininfo -display -noisy -checkgtk

$HOME/xsnow/pixmaps/tree.xpm

If present, xsnow will try this file for displaying the trees. The format must be xpm (X PixMap) format, see https://en.wikipedia.org/wiki/X_PixMap .
NOTE: when this file is present, no menu will appear.

$HOME/xsnow/pixmaps/santa<n>.xpm

where <n> = 1,2,3,4. If present, xsnow will try this files (4 of them) for displaying Santa. The format must be xpm (X PixMap) format, see https://en.wikipedia.org/wiki/X_PixMap .
NOTE: when these files are present, no menu will appear.

EXAMPLES

$ xsnow -defaults # run with defaults.
$ xsnow # run using values from the config file.
$ xsnow -treetype 1,2 # use tree types 1 and 2.

BUGS

- Xsnow needs a complete rewrite: the code is a mess.
- The flags are not consistent, caused by trying to be
compatible with older versions.
- Xsnow stresses the Xserver too much.
- Xsnow does run in Wayland, but will not snow on all windows.
- Xsnow tries to create a click-through window. This is not successful
in for example FVWM/xcompmgr. In that case, xsnow tries to keep
the snow window below all others, resulting in a transient effect
when you click on the desktop. Sadly, no FVWM menu will appear...
- Remnants of fluffy snow can persist after removing the
fallen snow. These will gradually disappear, so no big deal.
- Remnants of meteorites can persist after passage of Santa.
These will eventually be wiped out by snow or Santa.
- Xsnow tries to adapt its snowing window if the display
settings are changed while xsnow is running.
This does not function always well.
- In multi-screen environments, it depends on the display settings
if it is snowing on all screens. Experiment!