roll

#!/usr/bin/env lua

local args={...}
local n=args[1]
local m=args[2]

math.randomseed(os.time())

local errored=false
if n=='choice' then
	local choices={}
	for l in io.lines() do
		table.insert(choices, l)
	end
	io.write(choices[math.random(#choices)])
elseif n=='magic' then
	local choices={
		"As I see it, yes",
		"Don't count on it",
		"Yes",
		"Outlook good",
		"Concentrate and ask again",
		"Yes, definitely",
		"Signs point to yes",
		"It is decidedly so",
		"Ask again later",
		"Most likely",
		"Outlook not so good",
		"My sources say no",
		"Better not tell you now",
		"You may rely on it",
		"Without a doubt",
		"Very doubtful",
		"Cannot predict now",
		"Reply hazy try again",
		"It is certain",
		"My reply is no"
	}
	io.write(choices[math.random(#choices)])
	io.write '\n'
elseif tonumber(n) then
	n=tonumber(n)
	m=tonumber(m)
	if m then
		if m<n then
			m, n=n, m
		end
		io.write(math.random(n, m))
	else
		if n==0 then
			errored=true
		else
			io.write(math.random(n))
		end
	end
else
	errored=true
end

if errored then
	io.stderr:write "Usage:\n"
	io.stderr:write "\troll <n>\n"
	io.stderr:write "\t\tRolls a pseudorandom integer between 1 and n inclusive\n"
	io.stderr:write "\troll <n> <m>\n"
	io.stderr:write "\t\tRolls a pseudorandom integer between n and m (which don't have to be in order), inclusive\n"
	io.stderr:write "\troll choice\n"
	io.stderr:write "\t\tReturns a random line from stdin, without the trailing eol\n"
	io.stderr:write "\troll magic\n"
	io.stderr:write "\t\tRolls a magic 20 (aka magic 8 pool)\n"
end