* DiscImageChef.DiscImages/CPCDSK.cs:

* DiscImageChef.DiscImages/DiscImageChef.DiscImages.csproj:
	  Added CPCEMU Disk File and Extended Disk File.

	* TODO:
	* README.md:
	* DiscImageChef.Filesystems/CPM/CPM.cs:
	* DiscImageChef.Filesystems/CPM/Dir.cs:
	* DiscImageChef.Filesystems/CPM/Info.cs:
	* DiscImageChef.Filesystems/CPM/File.cs:
	* DiscImageChef.Filesystems/CPM/Xattr.cs:
	* DiscImageChef.Filesystems/CPM/Super.cs:
	* DiscImageChef.Filesystems/CPM/Consts.cs:
	* DiscImageChef.Filesystems/CPM/Structs.cs:
	* DiscImageChef.Filesystems/CPM/cpmdefs.xml:
	* DiscImageChef.Filesystems/CPM/Definitions.cs:
	* DiscImageChef.Filesystems/DiscImageChef.Filesystems.csproj:
	  Added CP/M filesystem, closes #29.

DiscImageChef.Filesystems/CPM/Dir.cs

@@ -5,11 +5,11 @@
 // Filename       : Dir.cs
 // Author(s)      : Natalia Portillo <claunia@claunia.com>
 //
-// Component      : Component
+// Component      : CP/M filesystem plugin.
 //
 // --[ Description ] ----------------------------------------------------------
 //
-//     Description
+//      Methods to show the CP/M filesystem directory.
 //
 // --[ License ] --------------------------------------------------------------
 //
@@ -29,13 +29,107 @@
 // ----------------------------------------------------------------------------
 // Copyright © 2011-2016 Natalia Portillo
 // ****************************************************************************/
+
 using System;
+using System.Collections.Generic;
+using System.Runtime.InteropServices;
+using System.Text;
+
 namespace DiscImageChef.Filesystems.CPM
 {
-    public class Dir
+    partial class CPM : Filesystem
     {
-        public Dir()
+        public override Errno ReadDir(string path, ref List<string> contents)
         {
+            if(!mounted)
+                return Errno.AccessDenied;
+
+            if(!string.IsNullOrEmpty(path) && string.Compare(path, "/", StringComparison.OrdinalIgnoreCase) != 0)
+                return Errno.NotSupported;
+
+            contents = dirList;
+
+            return Errno.NoError;
+        }
+
+        /// <summary>
+        /// Checks that the given directory blocks follow the CP/M filesystem directory specification
+        /// Corrupted directories will fail.
+        /// FAT firectories will false positive if all files start with 0x05, and do not use full extentions, for example:
+        /// "σAFILE.GZ" (using code page 437)
+        /// </summary>
+        /// <returns>False if the directory does not follow the directory specification</returns>
+        /// <param name="directory">Directory blocks.</param>
+        bool CheckDir(byte[] directory)
+        {
+            try
+            {
+                if(directory == null)
+                    return false;
+
+                int fileCount = 0;
+
+                for(int off = 0; off < directory.Length; off += 32)
+                {
+                    DirectoryEntry entry = new DirectoryEntry();
+                    IntPtr dirPtr = Marshal.AllocHGlobal(32);
+                    Marshal.Copy(directory, off, dirPtr, 32);
+                    entry = (DirectoryEntry)Marshal.PtrToStructure(dirPtr, typeof(DirectoryEntry));
+                    Marshal.FreeHGlobal(dirPtr);
+
+                    if((entry.statusUser & 0x7F) < 0x20)
+                    {
+                        for(int f = 0; f < 8; f++)
+                        {
+                            if(entry.filename[f] < 0x20 && entry.filename[f] != 0x00)
+                                return false;
+                        }
+
+                        for(int e = 0; e < 3; e++)
+                        {
+                            if(entry.extension[e] < 0x20 && entry.extension[e] != 0x00)
+                                return false;
+                        }
+
+                        if(!ArrayHelpers.ArrayIsNullOrWhiteSpace(entry.filename))
+                            fileCount++;
+                    }
+                    else if(entry.statusUser == 0x20)
+                    {
+                        for(int f = 0; f < 8; f++)
+                        {
+                            if(entry.filename[f] < 0x20 && entry.filename[f] != 0x00)
+                                return false;
+                        }
+
+                        for(int e = 0; e < 3; e++)
+                        {
+                            if(entry.extension[e] < 0x20 && entry.extension[e] != 0x00)
+                                return false;
+                        }
+
+                        label = Encoding.ASCII.GetString(directory, off + 1, 11).Trim();
+                        labelCreationDate = new byte[4];
+                        labelUpdateDate = new byte[4];
+                        Array.Copy(directory, off + 24, labelCreationDate, 0, 4);
+                        Array.Copy(directory, off + 28, labelUpdateDate, 0, 4);
+                    }
+                    else if(entry.statusUser == 0x21)
+                    {
+                        if(directory[off + 1] == 0x00)
+                        {
+                            thirdPartyTimestamps = true;
+                        }
+                        else standardTimestamps |= (directory[off + 21] == 0x00 && directory[off + 31] == 0x00);
+                    }
+                }
+
+                return fileCount > 0;
+            }
+            catch
+            {
+                return false;
+            }
         }
     }
 }