[ComputerCraft][Program] PassGen

--[[
    [Program] PassGen
    @version 1.0, 09/02/2014, HK98
    @author Hellkid98, HK98
--]]


local args = {...}
--# Checking for errors
if #args < 2 then
    error( "Usage: <Lenght> <Output file>", 0 )
end
if not tonumber( args[1] ) then
    error( "Usage: <Lenght> <Output file>", 0 )
end
if fs.exists( args[2] ) then
    error( "File exists!\nUsage: <Lenght> <Output file>", 0 )
end


--# All the available characters
local characters = {
    "A","B","C","D","E","F","G","H","I","J","K","L",
    "M","N","O","P","Q","R","S","T","U","V","W","X",
    "Y","Z","0","1","2","3","4","5","6","7","8","9",
}


local str = ""
for i = 1, tonumber( args[1] ) do
    local s = characters[math.random( 1, #characters )]
    if math.random(1,2) % 2 == 0 then
        s = string.lower( s )
    end
    str = str .. s
end
local f = fs.open( args[2], "w" )
f.writeLine( str )
f.close()
print( "Password generated: " .. str )