Base4225

base4225.fs

open System
open System.IO
open System.Text
open System.Collections.Generic
open System.Linq

let base64 = List.concat[['A'..'Z']; ['a'..'z']; ['0'..'9']; ['+'; '/'; '=']]

let b2u b1 b2 =
  let i1 = List.findIndex ((=) b1) base64 in
  let i2 = List.findIndex ((=) b2) base64 in
  let offset = i2 + (i1 * 65) in
  let a = offset / (64 * 64) in
  let b = (offset - (a * 64 * 64)) / 64 in
  let c = (offset - (a * 64 * 64) - (b * 64)) in
  let x = [0xf0; 0xa0 + a; 0x80 + b; 0x80 + c] |> List.map (byte) |> Seq.toArray |> Encoding.UTF8.GetString in
  //printfn "%A" x; Console.ReadLine() |> ignore;
  x

let u2b (s : string) =
  let bs = Encoding.UTF8.GetBytes(s) in
  if BitConverter.ToInt32(bs |> Seq.rev |> Seq.toArray, 0) < 0xf0a08080 then
    ""
  else
    let i = ((int)bs.[1] - 0xa0) * 64 * 64
          + ((int)bs.[2] - 0x80) * 64
          + ((int)bs.[3] - 0x80) in
    let a = i / 65 in
    let b = i - a * 65 in
    let x = [base64.[a]; base64.[b]] |> String.Concat in
    //printfn "%s" x; Console.ReadLine() |> ignore;
    x

let f2k f =
  let bs = File.ReadAllBytes (f) in
  let b64 = Convert.ToBase64String (bs) |> Seq.toArray in
  let ln = b64.Length / 2 in
  List.map (fun i -> b2u b64.[i * 2 - 2] b64.[i * 2 - 1]) [1..ln] |> String.Concat

let k2f (s : string) =
  let ln = s.Length / 2 in
  let b64 = List.map (fun i -> String([|s.[i * 2 - 2]; s.[i * 2 - 1]|]) |> u2b) [1..ln] |> String.Concat in
  Convert.FromBase64String (b64)

[<EntryPoint>]
let main argv = 
  let d = argv.Contains "-d" || argv.Contains "--decode" in
  let argv = Seq.filter (fun x -> not (x.Equals "-d" || x.Equals "--decode")) argv |> Seq.toArray
  if argv.Length > 0 then
    let fn = argv.[0] in
    try
      if File.Exists fn then
        if d then
          let r = File.ReadAllBytes(fn) in
          let bs = Encoding.UTF8.GetString(r) |> k2f in
          use stdout = Console.OpenStandardOutput(bs.Length) in
            stdout.Write(bs, 0, bs.Length)
          0
        else
          let s = f2k fn in
          printf "%s" s
          0
      else
        printfn "%s" ("base4225: file " + fn + " not found")
        1 
    with
      | e ->
        printfn "%s" "base4225: fatal error: "
        e.ToString () |> printfn "%s"
        1
  else
    printfn "%s" "usage: base4225 [OPTION]... [FILE]"
    printfn "%s" "Base4225 encode or decode FILE to standard output."
    Console.WriteLine ()
    printfn "%s" "OPTIONS:"
    printfn "%s" "  -d, --decode ... decode data"
    0

gif.example

𠒅𠥫𠎑𠦆𠂢𠀊𠀏𠘘𠀀𠀘𠇱𠘑𠾀𠶧𠗶𠐳𠅏𠠯𠂝𠪮𠒸𠵂𠄇𠂣𠻛𠭥𠐉𠰑𠺯𠆫𠡅𠰾𠃐𠋃𠪘𡀾𠷍𠽳𠇛𠜣𠃬𠒎𠓀𠄤𠄪𠣥𠶩𠥗𠒎𠌣𠂋𠒱𠞆𠐚𠂀𠹩𠆉𠌌𠀎𠤙𠳱𠠎𠸢𠽣𠇒𠫇𠡒𠡽𠓻𠌔𠄧𠺫𠣷𠡞𠋚𡀾𡀾𠐷𠆦𠭗𠌁𠟆𠯙𠀡𠇄𡀕𠮲𠩽𠔀𠴙𠷋𠭕𠈑𠞙𠛴𠊳𠭓𠅢𠖃𠼺𡀼𠠝𠹼𠉓𠕈𠎸𡀕𠹚𠆠𠷠𠖘𠐟𠄦𠹭𠊒𠘽𠈷𠣨𠦨𠙵𠣆𠲞𠡪𠼥𠹇𠹪𠈎𠕳𠒮𠗥𠰌𠤊𠺈𠽤𠆛𠾲𠝘𠄟𠄈𠜹𠇼𠩃𠈬𠞱𠬮𠭧𠘅𡀽𠾊𠐶𠅹𠛅𠾹𠘇𠺢𠡂𠇁𠕉𠈧𡀾𠽏𠍳𠚅𠴲𡀺𠣒𠣪𠷀𠣉𠭽𠏭𠀪𠇃𠂦𠟢𠈦𠈠𠒂𠗫𠉒𠔬𠜳𠆢𠀠𠆗𠩀𠄛𠣻𠲥𠪊𠡅𠤿𠆻𠾁𠋢𠀩𠌞𠵮𠉍𠣇𠻙𠽥𠄒𠬏𠫃𠊛𠣰𠴲𡀻𠃙𠩑𠑵𠕊𠹐𠇙𠔰𠈒𠒗𠙤𠈏𠂦𠗏𡀱𠑗𠜨𠇾𠾼𠽷𠉓𠮑𠎀𠜶𠆩𠞭𠢄𠢖𠜋𠡵𠞌𡀾𠻉𠈆𠹽𠉤𠜓𠳸𠮄𠶅𠋄𠤿𠆞𠳽𠶛𠚝𠢅𠌟𠆲𠤔𠰳𠕅𠐨𠴙𠿯𠄤𠊜𠰰𠀀𠀀𠂢𠀊𠀀𠀇𠒉𠀡𠡂𠄴𠟖𠎕𠙋𠀣𠢒𠪒𠐀𠞮𠟐𠹩𠃌𠀾𠔪𠂒𠐣𠹖𠎵𠕒𠐦𠂤𠘙𠈳𠋝𠆩𠀺𠊌𠏅𠡞𠎱𠹶𠘜𠆈𠧺𠩟𠐓𠹧𠢒𠉬𠈙𠒢𠢙𠎧𠋳𠎏𠀃𠭬