open Printf
open ExtLib

let vtk = "test.vtk";;

let grabVtkSizeInfo path =
        let ic = open_in path in
        let rec iterateTillInfoFilled l channel =
                if (List.length l) = 2 then l
                else
                        let line = input_line channel in
                        if ((String.exists line "DIMENSIONS") || (String.exists line "POINT_DATA")) then
                                iterateTillInfoFilled ((List.tl (String.nsplit line " ")) :: l) channel
                        else iterateTillInfoFilled l channel
                in
        try Some (iterateTillInfoFilled [] ic) with End_of_file -> None




let pgm = "test.pgm";;

let oc = open_out pgm;;

let dimInfo = String.join " " (List.hd (List.filter (fun l -> (List.length l) > 1) (Option.default [] (grabVtkSizeInfo "140408aX_t01_ch01.vtk"))));;

fprintf oc "P2\n%d %d\n%d\n%s" 5 5 255 dimInfo;;