diff --git a/Interfaces/IArchive.cs b/Interfaces/IArchive.cs
index 16a7e7d..469be5d 100644
--- a/Interfaces/IArchive.cs
+++ b/Interfaces/IArchive.cs
@@ -35,9 +35,10 @@
 
 using System;
 using System.Collections.Generic;
-using System.IO;
 using System.Text;
 using Aaru.CommonTypes.Enums;
+using Aaru.CommonTypes.Structs;
+using FileAttributes = System.IO.FileAttributes;
 
 namespace Aaru.CommonTypes.Interfaces;
 
@@ -83,48 +84,51 @@ public interface IArchive
     /// <summary>Plugin author</summary>
     string Author { get; }
 
-    /// <summary>Identifies if the specified filter contains data recognizable by this archive instance</summary>
-    /// <param name="filter">Filter that contains the archive. This allows use to handle .tar.gz and similars.</param>
-    bool Identify(IFilter filter);
-
-    /// <summary>Opens the specified stream with this archive instance</summary>
-    /// <param name="filter">Filter that contains the archive. This allows use to handle .tar.gz and similars.</param>
-    ErrorNumber Open(IFilter filter, Encoding encoding);
-
     /// <summary>
     ///     Returns true if the archive has a file/stream/buffer currently opened and no
     ///     <see cref="M:Aaru.Filters.Filter.Close" /> has been issued.
     /// </summary>
-    bool IsOpened();
-
-    /// <summary>Closes all opened streams.</summary>
-    void Close();
+    /// <value><c>true</c> if the archive is opened, <c>false</c> otherwise.</value>
+    bool Opened { get; }
 
     /// <summary>Return a bitfield indicating the features supported by this archive type.</summary>
-    /// <returns>The <c>ArchiveSupportedFeature</c> bitfield.</returns>
+    /// <value>The <c>ArchiveSupportedFeature</c> bitfield.</value>
     /// <remarks>
     ///     If the archive is not opened, this returns the capabilities of the archive format, otherwise it returns the
     ///     capabilities in use by the currently opened archive.
     /// </remarks>
-    ArchiveSupportedFeature GetArchiveFeatures();
+    ArchiveSupportedFeature ArchiveFeatures { get; }
 
     /// <summary>Gets the number of entries (i.e. files) that are contained in this archive.</summary>
     /// <remarks>
     ///     Entries in this context can also mean directories or volume labels, for some types of archives that store
     ///     these explicitly. Do not rely on all entries being regular files!
     /// </remarks>
-    /// <returns>The number of files.</returns>
-    int GetNumberOfEntries();
+    /// <value>The number of files.</value>
+    int NumberOfEntries { get; }
+
+    /// <summary>Identifies if the specified filter contains data recognizable by this archive instance</summary>
+    /// <param name="filter">Filter that contains the archive. This allows use to handle .tar.gz and similars.</param>
+    bool Identify(IFilter filter);
+
+    /// <summary>Opens the specified stream with this archive instance</summary>
+    /// <param name="filter">Filter that contains the archive. This allows use to handle .tar.gz and similars.</param>
+    /// <param name="encoding">The encoding codepage to use for this archive.</param>
+    ErrorNumber Open(IFilter filter, Encoding encoding);
+
+    /// <summary>Closes the archive.</summary>
+    void Close();
 
     /// <summary>Gets the file name (and path) of the given entry in the archive.</summary>
     /// <remarks>
     ///     The path components are separated by a forward slash "/". <br /> The path should not start with a leading
     ///     slash (i.e. it should be relative, not absolute).
     /// </remarks>
-    /// <seealso cref="Stat(int)" />
+    /// <seealso cref="Stat" />
     /// <param name="entryNumber">The entry in the archive for which to return the file name.</param>
-    /// <returns>The file name, with (relative) path</returns>
-    string GetFilename(int entryNumber);
+    /// <param name="fileName">The file name, with (relative) path</param>
+    /// <returns>Error number.</returns>
+    ErrorNumber GetFilename(int entryNumber, out string fileName);
 
     /// <summary>
     ///     Gets the entry number for a particular file path in the archive. <c>fileName</c> is the relative path of the
@@ -136,58 +140,69 @@ public interface IArchive
     /// </remarks>
     /// <param name="fileName">The relative path for which to get the entry number.</param>
     /// <param name="caseInsensitiveMatch">If set, do a case insensitive matching and return the first file that matches.</param>
-    /// <returns>The number of the entry corresponding to the given path, or -1 if the path does not exist.</returns>
-    int GetEntryNumber(string fileName, bool caseInsensitiveMatch);
+    /// <param name="entryNumber">The number of the entry corresponding to the given path, or -1 if the path does not exist.</param>
+    /// <returns>Error number.</returns>
+    ErrorNumber GetEntryNumber(string fileName, bool caseInsensitiveMatch, out int entryNumber);
 
     /// <summary>Gets the (compressed) size of the given entry.</summary>
     /// <param name="entryNumber">The entry for which to get the compressed size.</param>
-    /// <returns>The compressed size of the entry, or 0 if the entry is not a regular file.</returns>
+    /// <param name="length">The compressed size of the entry, or 0 if the entry is not a regular file.</param>
+    /// <returns>Error number.</returns>
     /// <remarks>The return value is equal to the return value of <c>GetUncompressedSize()</c> if the file is not compressed.</remarks>
-    /// <seealso cref="GetUncompressedSize(int)" />
-    long GetCompressedSize(int entryNumber);
+    /// <seealso cref="GetUncompressedSize" />
+    ErrorNumber GetCompressedSize(int entryNumber, out long length);
 
     /// <summary>Gets the uncompressed size of the given entry.</summary>
     /// <param name="entryNumber">The entry for which to get the uncompressed size.</param>
-    /// <returns>The uncompressed size of the entry, or 0 if the entry is not a regular file.</returns>
+    /// <param name="length">The uncompressed size of the entry, or 0 if the entry is not a regular file.</param>
+    /// <returns>Error number.</returns>
     /// <remarks>The return value is equal to the return value of <c>GetCompressedSize()</c> if the file is not compressed.</remarks>
-    /// <seealso cref="GetCompressedSize(int)" />
-    long GetUncompressedSize(int entryNumber);
+    /// <seealso cref="GetCompressedSize" />
+    ErrorNumber GetUncompressedSize(int entryNumber, out long length);
 
     /// <summary>Gets the attributes of a file or directory.</summary>
-    /// <seealso cref="Stat(int)" />
-    /// <returns>Error number.</returns>
     /// <param name="entryNumber">The entry in the archive for which to retrieve the attributes.</param>
-    /// <returns>File attributes, or zero if the archive does not support attributes.</returns>
-    FileAttributes GetAttributes(int entryNumber);
+    /// <param name="attributes">File attributes, or zero if the archive does not support attributes.</param>
+    /// <returns>Error number.</returns>
+    /// <seealso cref="Stat" />
+    ErrorNumber GetAttributes(int entryNumber, out FileAttributes attributes);
 
     /// <summary>Lists all extended attributes, alternate data streams and forks of the given file.</summary>
     /// <param name="entryNumber">The entry in the archive for which to retrieve the list of attributes.</param>
-    /// <returns>List of extended attributes, alternate data streams and forks.</returns>
-    List<string> GetXAttrs(int entryNumber);
+    /// <param name="xattrs">List of extended attributes, alternate data streams and forks.</param>
+    /// <returns>Error number.</returns>
+    ErrorNumber ListXAttr(int entryNumber, out List<string> xattrs);
 
     /// <summary>Reads an extended attribute, alternate data stream or fork from the given file.</summary>
-    /// <returns>Error number.</returns>
     /// <param name="entryNumber">The entry in the archive for which to retrieve the XAttr.</param>
     /// <param name="xattr">Extended attribute, alternate data stream or fork name.</param>
     /// <param name="buffer">Buffer where the extended attribute data will be stored.</param>
-    /// <returns>Buffer with the XAttr data.</returns>
-    ErrorNumber GetXattr(int entryNumber, string xattr, out byte[] buffer);
+    /// <returns>Error number.</returns>
+    ErrorNumber GetXattr(int entryNumber, string xattr, ref byte[] buffer);
 
     /// <summary>Gets information about an entry in the archive.</summary>
     /// <remarks>Note that some of the data might be incomplete or not available at all, depending on the type of archive.</remarks>
-    /// <seealso cref="GetAttributes(int)" />
-    /// <seealso cref="GetFilename(int)" />
     /// <param name="entryNumber">The entry int he archive for which to get the information</param>
-    /// <returns>The available information about the entry in the archive</returns>
-    FileSystemInfo Stat(int entryNumber);
+    /// <param name="stat">The available information about the entry in the archive</param>
+    /// <returns>Error number.</returns>
+    /// <seealso cref="GetAttributes" />
+    /// <seealso cref="GetFilename" />
+    ErrorNumber Stat(int entryNumber, out FileEntryInfo stat);
 
     /// <summary>
     ///     Returns the Filter for the given entry. It will return <c>null</c> if the entry in question is not a regular
     ///     file (i.e. directory, volume label, etc.)
     /// </summary>
     /// <param name="entryNumber">The entry for which the Filter should be returned.</param>
-    /// <returns>The Filter for the given entry.</returns>
-    IFilter GetEntry(int entryNumber);
+    /// <param name="filter">The Filter for the given entry.</param>
+    /// <returns>Error number.</returns>
+    ErrorNumber GetEntry(int entryNumber, out IFilter filter);
 
+    /// <summary>
+    ///     Gets user readable information about the archive. The exact contents depend on the archive plugin implementation.
+    /// </summary>
+    /// <param name="filter">Filter that handles the archive.</param>
+    /// <param name="encoding">The encoding codepage to use with the archive.</param>
+    /// <param name="information">Variable that holds the user readable information.</param>
     void GetInformation(IFilter filter, Encoding encoding, out string information);
 }
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