setwallpaper aims to be able to change the desktop wallpaper, for any windowmanager.
The first argument is the image to use.
URLs are supported.
stretchfillfitcentertile
fillcentermaxscaletile
nonewallpapercenteredscaledstretchedzoomspanned
For compatibility:
fillis an alias forstretchedcenteris an alias forcenteredscaleis an alias forscaledtileis an alias forwallpaper