PotatOS Disk Upgrade Utility

--[[
PotatOS Tau has recently switched from a table format for disk signatures to a shiny, new hexadecimal one.
Existing disks can be upgraded with this utility.
]]

local function hexize(sig)
    local out = ""
    for _, v in pairs(sig) do
        out = out .. string.format("%.2x", v)
    end
    return out
end

local function fwrite(n, c)
    local f = fs.open(n, "w")
    f.write(c)
    f.close()
end

local function fread(n)
    local f = fs.open(n, "r")
    local out = f.readAll()
    f.close()
    return out
end

print "Place the disk to be upgraded in a connected disk drive."
local _, side = os.pullEvent "disk"
local path = fs.combine(disk.getMountPath(side), "signature")
if not fs.exists(path) then error "Inserted disk does not contain a signature!" end

fwrite(path, hexize(textutils.unserialize(fread(path))))
print "Done!"