--
-- Dumps a file to the screen.
--

function display(inp, n)
    local i
    if (type(inp) == "string") then
        inp = Input(inp)
    elseif (type(inp) ~= "table") then
        error("Display needs a string or an Input object")
    end
    
    i = 0
    
    while(not inp:isclosed()) do
        i = i + 1
        print(inp:read())
        if ((n ~= nil) and (i >= n)) then
            return
        end
    end
end


--
-- Squash characters into printable chars.
--

function pchar(n)
    if (not ((n >= 32) and (n <= 127))) then
        n = 46 -- aka '.' or 0x2e
    end
    return hex(n, "%c")
end


--
-- Does a hexadecimal dump on the screen of the file.
--

function hexdump(inp, from, to, width)
    local size, nlines, remaining, data_array, line, byte, outstring
    
    if (type(inp) == "string") then
        inp = Input(inp)
    elseif (type(inp) ~= "table") then
        error("Hexdump needs a string or an Input object")
    end
    
    size = inp:getsize()

    if (from == nil) then
        from = 0
    end
    
    if (to == nil) then
        to = size
    end
    
    if (to > size) then
        to = size
    end
    
    size = to - from
    
    if (width == nil) then
        width = 16
    end
    
    nlines = math.floor(size / width)
    remaining = math.mod(size, width)
    inp:seek(from)
    data_array = inp:read(size)
    
    for line = 0, nlines - 1, 1 do
        outstring = hex(line * width + from, "%08x   ")
        for byte = 0, width - 1, 1 do
            outstring = outstring .. hex(data_array[line * 16 + byte]) .. " "
        end
        outstring = outstring .. "  "
        for byte = 0, width - 1, 1 do
            outstring = outstring .. pchar(data_array[line * 16 + byte])
        end
        print(outstring)
    end

    if (remaining == 0) then
        return
    end
    
    outstring = hex(nlines * width + from, "%08x   ");
    for byte = 0, remaining - 1, 1 do
        outstring = outstring .. hex(data_array[nlines * 16 + byte]) .. " "
    end
    for byte = remaining + 1, width - 1, 1 do
        outstring = outstring .. "   "
    end
    outstring = outstring .. "  "
    for byte = 0, remaining - 1, 1 do
        outstring = outstring .. pchar(data_array[nlines * 16 + byte])
    end

    print(outstring)
end


--
-- Splits a string given a separator character into an array.
--

function split(str, at)
    local splut = {}

    if (type(str) ~= "string") then return nil end
    if (not str) then str = "" end

    if (not at) then
        table.insert(splut, str)
    else
        for n, c in string.gfind(str, '([^%'..at..']*)(%'..at..'?)') do
            table.insert(splut, n)

            if (c == '') then break end
        end
    end

    return splut
end