man rain (Jeux) - rain
NAME
rain - animated raindrops display
SYNOPSIS
[-d delay]
DESCRIPTION
The output of is modeled after the VAX/VMS program of the same name. To obtain the proper effect, either the terminal must be set for 9600 baud or the -d option must be used to specify a delay, in milliseconds, between each update. A reasonable delay is 120; the default is 0.
AUTHOR
Eric P. Scott