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Determine type of file without extension VB.NET

Question

Saturday, March 8, 2014 8:37 AM

Hi Guys,
Please I need help,

How can I programatically determine if a file type is (Application, Service or Batch File)?

Please take a look:
http://www.fileswap.com/dl/Bjca9UhkRG/

Nana,
Best Regards...

All replies (3)

Saturday, March 8, 2014 12:43 PM ✅Answered

Hello

It is possible via mime type of a file but it;s not 100% i.e. a blank bmp file may not work but with content it will.

But this will not tell you if the file is a service or batch file

Imports System.Runtime.InteropServices
Imports System.IO

Module Api_Code

    <DllImport("urlmon.dll", CharSet:=CharSet.Auto)> _
    Private Function FindMimeFromData(ByVal pBC As System.UInt32,
                                      <MarshalAs(UnmanagedType.LPStr)>
                                      ByVal pwzUrl As System.String, <MarshalAs(UnmanagedType.LPArray)>
                                      ByVal pBuffer() As Byte,
                                      ByVal cbSize As System.UInt32, <MarshalAs(UnmanagedType.LPStr)>
                                      ByVal pwzMimeProposed As System.String,
                                      ByVal dwMimeFlags As System.UInt32,
                                      ByRef ppwzMimeOut As System.UInt32,
                                      ByVal dwReserverd As System.UInt32) As System.UInt32
    End Function
    Public MIMETypesDictionary As New Dictionary(Of String, String)() From
        {
            {"ai", "application/postscript"},
            {"aif", "audio/x-aiff"},
            {"aifc", "audio/x-aiff"},
            {"aiff", "audio/x-aiff"},
            {"asc", "text/plain"},
            {"atom", "application/atom+xml"},
            {"au", "audio/basic"},
            {"avi", "video/x-msvideo"},
            {"bcpio", "application/x-bcpio"},
            {"bin", "application/octet-stream"},
            {"bmp", "image/bmp"},
            {"cdf", "application/x-netcdf"},
            {"cgm", "image/cgm"},
            {"class", "application/octet-stream"},
            {"cpio", "application/x-cpio"},
            {"cpt", "application/mac-compactpro"},
            {"csh", "application/x-csh"},
            {"css", "text/css"},
            {"dcr", "application/x-director"},
            {"dif", "video/x-dv"},
            {"dir", "application/x-director"},
            {"djv", "image/vnd.djvu"},
            {"djvu", "image/vnd.djvu"},
            {"dll", "application/octet-stream"},
            {"dmg", "application/octet-stream"},
            {"dms", "application/octet-stream"},
            {"doc", "application/msword"},
            {"docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document"},
            {"dotx", "application/vnd.openxmlformats-officedocument.wordprocessingml.template"},
            {"docm", "application/vnd.ms-word.document.macroEnabled.12"},
            {"dotm", "application/vnd.ms-word.template.macroEnabled.12"},
            {"dtd", "application/xml-dtd"},
            {"dv", "video/x-dv"},
            {"dvi", "application/x-dvi"},
            {"dxr", "application/x-director"},
            {"eps", "application/postscript"},
            {"etx", "text/x-setext"},
            {"exe", "application/octet-stream"},
            {"ez", "application/andrew-inset"},
            {"gif", "image/gif"},
            {"gram", "application/srgs"},
            {"grxml", "application/srgs+xml"},
            {"gtar", "application/x-gtar"},
            {"hdf", "application/x-hdf"},
            {"hqx", "application/mac-binhex40"},
            {"htm", "text/html"},
            {"html", "text/html"},
            {"ice", "x-conference/x-cooltalk"},
            {"ico", "image/x-icon"},
            {"ics", "text/calendar"},
            {"ief", "image/ief"},
            {"ifb", "text/calendar"},
            {"iges", "model/iges"},
            {"igs", "model/iges"},
            {"jnlp", "application/x-java-jnlp-file"},
            {"jp2", "image/jp2"},
            {"jpe", "image/jpeg"},
            {"jpeg", "image/jpeg"},
            {"jpg", "image/jpeg"},
            {"js", "application/x-javascript"},
            {"kar", "audio/midi"},
            {"latex", "application/x-latex"},
            {"lha", "application/octet-stream"},
            {"lzh", "application/octet-stream"},
            {"m3u", "audio/x-mpegurl"},
            {"m4a", "audio/mp4a-latm"},
            {"m4b", "audio/mp4a-latm"},
            {"m4p", "audio/mp4a-latm"},
            {"m4u", "video/vnd.mpegurl"},
            {"m4v", "video/x-m4v"},
            {"mac", "image/x-macpaint"},
            {"man", "application/x-troff-man"},
            {"mathml", "application/mathml+xml"},
            {"me", "application/x-troff-me"},
            {"mesh", "model/mesh"},
            {"mid", "audio/midi"},
            {"midi", "audio/midi"},
            {"mif", "application/vnd.mif"},
            {"mov", "video/quicktime"},
            {"movie", "video/x-sgi-movie"},
            {"mp2", "audio/mpeg"},
            {"mp3", "audio/mpeg"},
            {"mp4", "video/mp4"},
            {"mpe", "video/mpeg"},
            {"mpeg", "video/mpeg"},
            {"mpg", "video/mpeg"},
            {"mpga", "audio/mpeg"},
            {"ms", "application/x-troff-ms"},
            {"msh", "model/mesh"},
            {"mxu", "video/vnd.mpegurl"},
            {"nc", "application/x-netcdf"},
            {"oda", "application/oda"},
            {"ogg", "application/ogg"},
            {"pbm", "image/x-portable-bitmap"},
            {"pct", "image/pict"},
            {"pdb", "chemical/x-pdb"},
            {"pdf", "application/pdf"},
            {"pgm", "image/x-portable-graymap"},
            {"pgn", "application/x-chess-pgn"},
            {"pic", "image/pict"},
            {"pict", "image/pict"},
            {"png", "image/png"},
            {"pnm", "image/x-portable-anymap"},
            {"pnt", "image/x-macpaint"},
            {"pntg", "image/x-macpaint"},
            {"ppm", "image/x-portable-pixmap"},
            {"ppt", "application/vnd.ms-powerpoint"},
            {"pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation"},
            {"potx", "application/vnd.openxmlformats-officedocument.presentationml.template"},
            {"ppsx", "application/vnd.openxmlformats-officedocument.presentationml.slideshow"},
            {"ppam", "application/vnd.ms-powerpoint.addin.macroEnabled.12"},
            {"pptm", "application/vnd.ms-powerpoint.presentation.macroEnabled.12"},
            {"potm", "application/vnd.ms-powerpoint.template.macroEnabled.12"},
            {"ppsm", "application/vnd.ms-powerpoint.slideshow.macroEnabled.12"},
            {"ps", "application/postscript"},
            {"qt", "video/quicktime"},
            {"qti", "image/x-quicktime"},
            {"qtif", "image/x-quicktime"},
            {"ra", "audio/x-pn-realaudio"},
            {"ram", "audio/x-pn-realaudio"},
            {"ras", "image/x-cmu-raster"},
            {"rdf", "application/rdf+xml"},
            {"rgb", "image/x-rgb"},
            {"rm", "application/vnd.rn-realmedia"},
            {"roff", "application/x-troff"},
            {"rtf", "text/rtf"},
            {"rtx", "text/richtext"},
            {"sgm", "text/sgml"},
            {"sgml", "text/sgml"},
            {"sh", "application/x-sh"},
            {"shar", "application/x-shar"},
            {"silo", "model/mesh"},
            {"sit", "application/x-stuffit"},
            {"skd", "application/x-koan"},
            {"skm", "application/x-koan"},
            {"skp", "application/x-koan"},
            {"skt", "application/x-koan"},
            {"smi", "application/smil"},
            {"smil", "application/smil"},
            {"snd", "audio/basic"},
            {"so", "application/octet-stream"},
            {"spl", "application/x-futuresplash"},
            {"src", "application/x-wais-source"},
            {"sv4cpio", "application/x-sv4cpio"},
            {"sv4crc", "application/x-sv4crc"},
            {"svg", "image/svg+xml"},
            {"swf", "application/x-shockwave-flash"},
            {"t", "application/x-troff"},
            {"tar", "application/x-tar"},
            {"tcl", "application/x-tcl"},
            {"tex", "application/x-tex"},
            {"texi", "application/x-texinfo"},
            {"texinfo", "application/x-texinfo"},
            {"tif", "image/tiff"},
            {"tiff", "image/tiff"},
            {"tr", "application/x-troff"},

            {"tsv", "text/tab-separated-values"},
            {"txt", "text/plain"},
            {"ustar", "application/x-ustar"}, {
            "vcd", "application/x-cdlink"},
            {"vrml", "model/vrml"},
            {"vxml", "application/voicexml+xml"},
            {"wav", "audio/x-wav"},
            {"wbmp", "image/vnd.wap.wbmp"},
            {"wbmxl", "application/vnd.wap.wbxml"},
            {"wml", "text/vnd.wap.wml"},
            {"wmlc", "application/vnd.wap.wmlc"},
            {"wmls", "text/vnd.wap.wmlscript"},
            {"wmlsc", "application/vnd.wap.wmlscriptc"},
            {"wrl", "model/vrml"},
            {"xbm", "image/x-xbitmap"},
            {"xht", "application/xhtml+xml"},
            {"xhtml", "application/xhtml+xml"},
            {"xls", "application/vnd.ms-excel"},
            {"xml", "application/xml"},
            {"xpm", "image/x-xpixmap"},
            {"xsl", "application/xml"},
            {"xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"},
            {"xltx", "application/vnd.openxmlformats-officedocument.spreadsheetml.template"},
            {"xlsm", "application/vnd.ms-excel.sheet.macroEnabled.12"},
            {"xltm", "application/vnd.ms-excel.template.macroEnabled.12"},
            {"xlam", "application/vnd.ms-excel.addin.macroEnabled.12"},
            {"xlsb", "application/vnd.ms-excel.sheet.binary.macroEnabled.12"},
            {"xslt", "application/xslt+xml"}, {"xul", "application/vnd.mozilla.xul+xml"},
            {"xwd", "image/x-xwindowdump"},
            {"xyz", "chemical/x-xyz"},
            {"zip", "application/zip"}
        }
    Public Function getMimeFromFile(ByVal filename As String) As String
        If Not File.Exists(filename) Then
            Throw New FileNotFoundException(filename & " not found")
        End If

        Dim buffer(255) As Byte
        Using fs As New FileStream(filename, FileMode.Open)
            If fs.Length >= 256 Then
                fs.Read(buffer, 0, 256)
            Else
                fs.Read(buffer, 0, CInt(fs.Length))
            End If
        End Using
        Try
            Dim mimetype As System.UInt32
            FindMimeFromData(0, Nothing, buffer, 256, Nothing, 0, mimetype, 0)
            Dim mimeTypePtr As System.IntPtr = New IntPtr(mimetype)
            Dim mime As String = Marshal.PtrToStringUni(mimeTypePtr)
            Marshal.FreeCoTaskMem(mimeTypePtr)
            Return mime
        Catch e As Exception
            Return "unknown/unknown"
        End Try
    End Function
End Module

Demo

Dim value As String = getMimeFromFile("Somefile")
If MIMETypesDictionary.ContainsValue(value) Then
    For Each Item As KeyValuePair(Of String, String) In MIMETypesDictionary
        If Item.Value = value Then
            Console.WriteLine(Item.Key)
        End If
    Next
End If

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Saturday, March 8, 2014 9:31 AM

You cannot.

Success
Cor


Saturday, March 8, 2014 6:23 PM

Im pretty sure that explorer uses the extension, as a test I took a text file and renamed it to .exe, properties showed it as an executable.

You can examine the first few bytes and make a good guess for executables -

try this and this 

batch files are just text files that contain commands

services are executables