how can I read a binary file with in javascript (Cscript.exe)?

Question

I think I can't read a binary file with the Scripting.FileSystemObject class. Can I do it with ADODB.Stream?

Something else?

I want to get an array of bytes.

thanks.

Answer 1

Function ReadByteArray(strFileName)
Const adTypeBinary = 1
Dim bin
    Set bin = CreateObject("ADODB.Stream")
    bin.Type = adTypeBinary
    bin.Open
    bin.LoadFromFile strFileName
    ReadByteArray = bin.Read
End Function

From http://www.ericphelps.com/q193998/index.htm

Answer 2

I looked and found Reading and Writing Binary Files using JScript on codeproject.

Not quite what I wanted, but pretty close.

It uses ADODB.Stream to read a local file. It's apparently not possible to read a binary file using Scripting.FileSystemObject in a general way, because it's not possible to set the codepage using fso. fso always uses the ambient codepage, which means results will vary depending on the machine's configuration. ADODB.Stream allows the program to specify the codepage. The next step is to map from the "text" read into a regular hex byte. That's the part that the above article provides.

The result I used with success is below.

// BinaryFileReader.js
// ------------------------------------------------------------------
//
// give the ability to read a binary file into an array of bytes,
// to Javascript.
//
// the mapping is based on code from:
//   http://www.codeproject.com/KB/scripting/Exsead7.aspx
//
// Created    : Fri May 28 05:20:31 2010
// Last-saved : <2010-May-28 06:01:34>
//
// ------------------------------------------------------------------

(function(){

    BinaryFileReader = {};

    var FileReadTypes = {
        adTypeBinary : 1,
        adTypeText   : 2
    };

    var backward = [];
    backward['C7']   = '80';
    backward['FC']   = '81';
    backward['E9']   = '82';
    backward['E2']   = '83';
    backward['E4']   = '84';
    backward['E0']   = '85';
    backward['E5']   = '86';
    backward['E7']   = '87';
    backward['EA']   = '88';
    backward['EB']   = '89';
    backward['E8']   = '8A';
    backward['EF']   = '8B';
    backward['EE']   = '8C';
    backward['EC']   = '8D';
    backward['C4']   = '8E';
    backward['C5']   = '8F';
    backward['C9']   = '90';
    backward['E6']   = '91';
    backward['C6']   = '92';
    backward['F4']   = '93';
    backward['F6']   = '94';
    backward['F2']   = '95';
    backward['FB']   = '96';
    backward['F9']   = '97';
    backward['FF']   = '98';
    backward['D6']   = '99';
    backward['DC']   = '9A';
    backward['A2']   = '9B';
    backward['A3']   = '9C';
    backward['A5']   = '9D';
    backward['20A7'] = '9E';
    backward['192']  = '9F';
    backward['E1']   = 'A0';
    backward['ED']   = 'A1';
    backward['F3']   = 'A2';
    backward['FA']   = 'A3';
    backward['F1']   = 'A4';
    backward['D1']   = 'A5';
    backward['AA']   = 'A6';
    backward['BA']   = 'A7';
    backward['BF']   = 'A8';
    backward['2310'] = 'A9';
    backward['AC']   = 'AA';
    backward['BD']   = 'AB';
    backward['BC']   = 'AC';
    backward['A1']   = 'AD';
    backward['AB']   = 'AE';
    backward['BB']   = 'AF';
    backward['2591'] = 'B0';
    backward['2592'] = 'B1';
    backward['2593'] = 'B2';
    backward['2502'] = 'B3';
    backward['2524'] = 'B4';
    backward['2561'] = 'B5';
    backward['2562'] = 'B6';
    backward['2556'] = 'B7';
    backward['2555'] = 'B8';
    backward['2563'] = 'B9';
    backward['2551'] = 'BA';
    backward['2557'] = 'BB';
    backward['255D'] = 'BC';
    backward['255C'] = 'BD';
    backward['255B'] = 'BE';
    backward['2510'] = 'BF';
    backward['2514'] = 'C0';
    backward['2534'] = 'C1';
    backward['252C'] = 'C2';
    backward['251C'] = 'C3';
    backward['2500'] = 'C4';
    backward['253C'] = 'C5';
    backward['255E'] = 'C6';
    backward['255F'] = 'C7';
    backward['255A'] = 'C8';
    backward['2554'] = 'C9';
    backward['2569'] = 'CA';
    backward['2566'] = 'CB';
    backward['2560'] = 'CC';
    backward['2550'] = 'CD';
    backward['256C'] = 'CE';
    backward['2567'] = 'CF';
    backward['2568'] = 'D0';
    backward['2564'] = 'D1';
    backward['2565'] = 'D2';
    backward['2559'] = 'D3';
    backward['2558'] = 'D4';
    backward['2552'] = 'D5';
    backward['2553'] = 'D6';
    backward['256B'] = 'D7';
    backward['256A'] = 'D8';
    backward['2518'] = 'D9';
    backward['250C'] = 'DA';
    backward['2588'] = 'DB';
    backward['2584'] = 'DC';
    backward['258C'] = 'DD';
    backward['2590'] = 'DE';
    backward['2580'] = 'DF';
    backward['3B1']  = 'E0';
    backward['DF']   = 'E1';
    backward['393']  = 'E2';
    backward['3C0']  = 'E3';
    backward['3A3']  = 'E4';
    backward['3C3']  = 'E5';
    backward['B5']   = 'E6';
    backward['3C4']  = 'E7';
    backward['3A6']  = 'E8';
    backward['398']  = 'E9';
    backward['3A9']  = 'EA';
    backward['3B4']  = 'EB';
    backward['221E'] = 'EC';
    backward['3C6']  = 'ED';
    backward['3B5']  = 'EE';
    backward['2229'] = 'EF';
    backward['2261'] = 'F0';
    backward['B1']   = 'F1';
    backward['2265'] = 'F2';
    backward['2264'] = 'F3';
    backward['2320'] = 'F4';
    backward['2321'] = 'F5';
    backward['F7']   = 'F6';
    backward['2248'] = 'F7';
    backward['B0']   = 'F8';
    backward['2219'] = 'F9';
    backward['B7']   = 'FA';
    backward['221A'] = 'FB';
    backward['207F'] = 'FC';
    backward['B2']   = 'FD';
    backward['25A0'] = 'FE';
    backward['A0']   = 'FF';

    var hD="0123456789ABCDEF";

    var d2h = function(d)
    {
        var h = hD.substr(d&15,1);
        while(d>15) {d>>>=4;h=hD.substr(d&15,1)+h;}
        return h;
    }

    var h2d = function(h)
    {
        return parseInt(h,16);
    }

    var toByteArray = function(inString) {
        var encArray = [];
        var sL = inString.length;
        for (var i=0;i<sL;i++) {
            var cc = inString.charCodeAt(i);
            if(cc>=128) {
                var h = backward[''+d2h(cc)];
                cc = h2d(h);
            }
            encArray.push(cc);
        }
        return encArray;
    }


    var _internalReadAll = function(path) {
        var bs = WScript.CreateObject("ADODB.Stream")
        bs.Type = FileReadTypes.adTypeText;
        bs.CharSet = '437';
        bs.Open();
        bs.LoadFromFile(path);
        var what = bs.ReadText;
        bs.Close();
        return what;
    }

    BinaryFileReader.ReadAllBytes = function(name)
    {
        var string = _internalReadAll(name);
        return toByteArray(string);
    }

})();

And usage is:

    var bytes = BinaryFileReader.ReadAllBytes(filename);

Answer 3

It also works to read the file as a binary, and then use VBScript to transform the object that comes back (an array of variant) into a Javascript array of bytes. To do that you need to mix VBScript and Javascript together using a .wsf file. You still need ADODB.Stream.

<job id="Something">
  <script id="BFRHelper.vbs" language="VBScript">
    Public Function VbBinaryToArray(Binary)
        Dim i
        ReDim byteArray(LenB(Binary))
        For i = 1 To LenB(Binary)
            byteArray(i-1) = AscB(MidB(Binary, i, 1))
        Next
        VbBinaryToArray = byteArray
    End Function
  </script>

  <script language="JavaScript" id="BFR2.js">

    (function(){

        BinaryFileReader = {};

        var FileReadTypes = {
            adTypeBinary : 1,
            adTypeText   : 2
        };

        BinaryFileReader.ReadAllBytes = function(path)
        {
            var bs = WScript.CreateObject("ADODB.Stream");
            bs.Type = FileReadTypes.adTypeBinary;
            bs.Open();
            bs.LoadFromFile(path);
            var what = bs.Read;
            bs.Close();
            var array = VbBinaryToArray(what).toArray();
            // I find the length property is 1 higher than it ought to be
            var aL = array.length;
            array.length = aL -1;
            return array;
        };
    })();

    var content = BinaryFileReader.ReadAllBytes(path); 

  </script>
</job>