printlargefiles.fs

open System.IO
open System.Collections.Generic

let rec getSize  =
    let memorize = new Dictionary<string, int64>()
    fun dir ->
        if memorize.ContainsKey(dir) then
            memorize.[dir]
        else
            let size =
                try
                    let dirSize =
                                Directory.GetFiles(dir)
                                |> Seq.map (fun path -> 
                                                    let fi = new FileInfo(path)
                                                    fi.Length)
                                |> Seq.fold (+) 0L
                    Directory.GetDirectories(dir) |> Seq.fold (fun acc dir -> acc + (getSize dir)) dirSize
                with _ -> 0L
            memorize.Add(dir, size)
            size

let printLargeDirs startDir limit =
    let rec loop intend dir =
        let size = getSize dir
        printfn "%s %s: %iMB" dir intend (size / 1000000L)
        if size > limit then
            for dir in Directory.GetDirectories dir do
            loop (intend + "\t") dir
    loop "" startDir

[<EntryPoint>]
let main(args: array<string>) =
    if args.Length <> 2 then
        printfn "usage: startdir limit (mb)"
        1
    else
        printLargeDirs (args.[0]) ((int64 args.[1]) * 1000000L)
        0