Add -out option for file output and fix stdin detection logic

- Add -out/-o option to save decode/encode output to files
- Encoded files are saved as binary, console still shows hex strings
- Decoded XML files are saved as text
- Fix stdin detection logic to prioritize command line arguments
- Add missing System.Collections.Generic import for List<string> usage
- File extension auto-processing now supports -out option
- Clean up data folder with renamed files (data0-3.dump/xml)

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.claude/settings.local.json

@@ -0,0 +1,17 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(dotnet build)",
+      "Bash(dotnet run:*)",
+      "Bash(git add:*)",
+      "Bash(git commit:*)",
+      "Bash(git push:*)",
+      "Read(//c/Program Files/Wireshark/plugins/**)",
+      "WebSearch",
+      "WebFetch(domain:github.com)",
+      "Bash(dir data)"
+    ],
+    "deny": [],
+    "ask": []
+  }
+}

Data/Dump/01_V2GMSG-SDP_Request.txt

@@ -0,0 +1,5 @@
+0000   33 33 00 00 00 01 10 22 33 44 55 66 86 dd 60 00   33....."3DUf..`.
+0010   00 00 00 12 11 ff fe 80 00 00 00 00 00 00 12 22   ..............."
+0020   33 ff fe 44 55 66 ff 02 00 00 00 00 00 00 00 00   3..DUf..........
+0030   00 00 00 00 00 01 c3 51 3b 0e 00 12 c8 18 01 fe   .......Q;.......
+0040   90 00 00 00 00 02 10 00                           ........

Data/Dump/02_V2GMSG-SDP_Response.txt

@@ -0,0 +1,6 @@
+0000   10 22 33 44 55 66 80 34 28 2e 23 dd 86 dd 60 00   ."3DUf.4(.#...`.
+0010   00 00 00 24 11 ff fe 80 00 00 00 00 00 00 82 34   ...$...........4
+0020   28 ff fe 2e 23 dd fe 80 00 00 00 00 00 00 12 22   (...#.........."
+0030   33 ff fe 44 55 66 3b 0e c3 51 00 24 5e 42 01 fe   3..DUf;..Q.$^B..
+0040   90 01 00 00 00 14 fe 80 00 00 00 00 00 00 82 34   ...............4
+0050   28 ff fe 2e 23 dd d1 21 10 00                     (...#..!..

Data/Dump/03-V2GMSG-SAP_SupportedAppProtocolReq.txt

@@ -0,0 +1,8 @@
+0000   80 34 28 2e 23 dd 10 22 33 44 55 66 86 dd 60 00   .4(.#.."3DUf..`.
+0010   00 00 00 40 06 ff fe 80 00 00 00 00 00 00 12 22   ...@..........."
+0020   33 ff fe 44 55 66 fe 80 00 00 00 00 00 00 82 34   3..DUf.........4
+0030   28 ff fe 2e 23 dd c3 65 d1 21 00 63 9b 07 2c c5   (...#..e.!.c..,.
+0040   4a 30 50 18 11 1c d4 f8 00 00 01 fe 80 01 00 00   J0P.............
+0050   00 24 80 00 eb ab 93 71 d3 4b 9b 79 d1 89 a9 89   .$.....q.K.y....
+0060   89 c1 d1 91 d1 91 81 89 99 d2 6b 9b 3a 23 2b 30   ..........k.:#+0
+0070   02 00 00 0c 38 40                                 ....8@

Data/Dump/04-V2GMSG-SAP_SupportedAppProtocolRes.txt

@@ -0,0 +1,6 @@
+0000   10 22 33 44 55 66 80 34 28 2e 23 dd 86 dd 60 00   ."3DUf.4(.#...`.
+0010   00 00 00 20 06 ff fe 80 00 00 00 00 00 00 82 34   ... ...........4
+0020   28 ff fe 2e 23 dd fe 80 00 00 00 00 00 00 12 22   (...#.........."
+0030   33 ff fe 44 55 66 d1 21 c3 65 2c c5 4a 30 00 63   3..DUf.!.e,.J0.c
+0040   9b 33 50 18 0b 3c 96 5f 00 00 01 fe 80 01 00 00   .3P..<._........
+0050   00 04 80 40 00 c0                                 ...@..

Data/dump0.dump

@@ -1,7 +0,0 @@
-0000   10 22 33 44 55 66 80 34 28 2e 23 dd 86 dd 60 00   ."3DUf.4(.#...`.
-0010   00 00 00 33 06 ff fe 80 00 00 00 00 00 00 82 34   ...3...........4
-0020   28 ff fe 2e 23 dd fe 80 00 00 00 00 00 00 12 22   (...#.........."
-0030   33 ff fe 44 55 66 d1 21 c3 65 2c c5 61 f8 00 63   3..DUf.!.e,.a..c
-0040   ae c9 50 18 08 a8 72 51 00 00 01 fe 80 01 00 00   ..P...rQ........
-0050   00 17 80 98 02 10 50 90 8c 0c 0c 0e 0c 51 80 00   ......P......Q..
-0060   00 00 20 40 c4 08 a0 30 00                        .. @...0.

Data/test_decode.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ns1:V2G_Message xmlns:ns1="urn:iso:15118:2:2013:MsgDef" xmlns:ns2="urn:iso:15118:2:2013:MsgHeader" xmlns:ns3="urn:iso:15118:2:2013:MsgBody" xmlns:ns4="urn:iso:15118:2:2013:MsgDataTypes">
+  <ns1:Header>
+    <ns2:SessionID>4142423030303831</ns2:SessionID>
+  </ns1:Header>
+  <ns1:Body>
+    <ns3:WeldingDetectionReq>
+      <ns3:DC_EVStatus>
+        <ns4:EVReady>True</ns4:EVReady>
+        <ns4:EVErrorCode>NO_ERROR</ns4:EVErrorCode>
+        <ns4:EVRESSSOC>100</ns4:EVRESSSOC>
+      </ns3:DC_EVStatus>
+    </ns3:WeldingDetectionReq>
+
+  </ns1:Body>
+</ns1:V2G_Message>

Data/test_exi.hex

@@ -1 +0,0 @@
-8098021050908C0C0C0E0C5211003200

Program.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 
@@ -8,9 +9,43 @@ namespace V2GProtocol
     {
         static void Main(string[] args)
         {
-            Console.WriteLine("=== V2G Transfer Protocol Decoder/Encoder ===");
+            // Only show header for help or analysis mode (not for encode/decode operations)
-            Console.WriteLine("ISO 15118-2 / DIN SPEC 70121 / SAP Protocol");
+            bool showHeader = false;
-            Console.WriteLine();
+            
+            if (args.Length == 0)
+            {
+                showHeader = true;
+            }
+            else if (args.Length > 0)
+            {
+                string firstArg = args[0].ToLower();
+                
+                // Check if it's help command
+                if (firstArg == "--help" || firstArg == "-h")
+                {
+                    showHeader = true;
+                }
+                // Check if it's a file for analysis mode (only .dump/.txt without options)
+                else if (File.Exists(args[0]) && args.Length == 1)
+                {
+                    string extension = Path.GetExtension(args[0]).ToLower();
+                    
+                    // Only show header for analysis mode (.dump/.txt)
+                    // NOT for auto-conversion (.hex, .xml)
+                    if (extension == ".dump" || extension == ".txt")
+                    {
+                        showHeader = true;
+                    }
+                    // .hex and .xml are auto-conversion, no header
+                }
+            }
+
+            if (showHeader)
+            {
+                Console.WriteLine("=== V2G Transfer Protocol Decoder/Encoder ===");
+                Console.WriteLine("ISO 15118-2 / DIN SPEC 70121 / SAP Protocol");
+                Console.WriteLine();
+            }
 
             try
             {
@@ -45,20 +80,58 @@ namespace V2GProtocol
                 // 두 번째 인자가 옵션인 경우 (filename --decode, filename --encode)
                 else if (args.Length >= 2 && (args[1].ToLower() == "--decode" || args[1].ToLower() == "-d"))
                 {
-                    // filename --decode 형태
+                    // filename --decode 형태 - 나머지 인자들도 전달
-                    string[] newArgs = { args[1], args[0] }; // 순서를 바꿔서 --decode filename 형태로 만듦
+                    var newArgs = new List<string> { args[1], args[0] };
-                    HandleDecodeCommand(newArgs);
+                    for (int i = 2; i < args.Length; i++)
+                        newArgs.Add(args[i]);
+                    HandleDecodeCommand(newArgs.ToArray());
                 }
                 else if (args.Length >= 2 && (args[1].ToLower() == "--encode" || args[1].ToLower() == "-e"))
                 {
-                    // filename --encode 형태
+                    // filename --encode 형태 - 나머지 인자들도 전달
-                    string[] newArgs = { args[1], args[0] }; // 순서를 바꿔서 --encode filename 형태로 만듦
+                    var newArgs = new List<string> { args[1], args[0] };
-                    HandleEncodeCommand(newArgs);
+                    for (int i = 2; i < args.Length; i++)
+                        newArgs.Add(args[i]);
+                    HandleEncodeCommand(newArgs.ToArray());
                 }
                 // 파일명만 전달된 경우 (분석 모드)
                 else if (File.Exists(args[0]))
                 {
-                    AnalyzeFile(args[0]);
+                    // Check file extension to determine default action
+                    string extension = Path.GetExtension(args[0]).ToLower();
+                    
+                    if (extension == ".dump" || extension == ".txt")
+                    {
+                        // Hex dump files - use full analysis mode
+                        AnalyzeFile(args[0]);
+                    }
+                    else if (extension == ".hex")
+                    {
+                        // .hex files - automatically decode to XML
+                        var autoArgs = new List<string> { "--decode", args[0] };
+                        // Add remaining args (like -out)
+                        for (int i = 1; i < args.Length; i++)
+                            autoArgs.Add(args[i]);
+                        HandleDecodeCommand(autoArgs.ToArray());
+                    }
+                    else if (extension == ".xml")
+                    {
+                        // .xml files - automatically encode to EXI
+                        var autoArgs = new List<string> { "--encode", args[0] };
+                        // Add remaining args (like -out)
+                        for (int i = 1; i < args.Length; i++)
+                            autoArgs.Add(args[i]);
+                        HandleEncodeCommand(autoArgs.ToArray());
+                    }
+                    else
+                    {
+                        // Unknown extension - require explicit option
+                        Console.WriteLine($"Error: Unknown file extension '{extension}'. Please specify operation:");
+                        Console.WriteLine($"  {Path.GetFileName(args[0])} --decode   # To decode as EXI to XML");
+                        Console.WriteLine($"  {Path.GetFileName(args[0])} --encode   # To encode as XML to EXI");
+                        Console.WriteLine($"  OR use: --decode {args[0]} / --encode {args[0]}");
+                        return;
+                    }
                 }
                 else
                 {
@@ -75,71 +148,87 @@ namespace V2GProtocol
         static void ShowUsage()
         {
             Console.WriteLine("Usage:");
-            Console.WriteLine("  V2GDecoder.exe [file.txt]                     # Analyze hex dump file");
+            Console.WriteLine("  V2GDecoder.exe [file.dump/.txt]               # Analyze hex dump file");
+            Console.WriteLine("  V2GDecoder.exe [file.hex]                     # Auto-decode hex to XML");
+            Console.WriteLine("  V2GDecoder.exe [file.xml]                     # Auto-encode XML to EXI");
             Console.WriteLine("  V2GDecoder.exe --decode <exi_hex_or_file>      # Decode EXI to XML");
             Console.WriteLine("  V2GDecoder.exe --encode <xml_file_or_string>   # Encode XML to EXI");
-            Console.WriteLine("  V2GDecoder.exe <file> --decode                 # Decode file content to XML");
+            Console.WriteLine("  V2GDecoder.exe <file> --decode [-out file]     # Force decode operation");
-            Console.WriteLine("  V2GDecoder.exe <file> --encode                 # Encode file content to EXI");
+            Console.WriteLine("  V2GDecoder.exe <file> --encode [-out file]     # Force encode operation");
             Console.WriteLine("  V2GDecoder.exe --help                          # Show this help");
             Console.WriteLine();
+            Console.WriteLine("File Extension Auto-Processing:");
+            Console.WriteLine("  .dump, .txt    → Full analysis mode (network + V2G message)");
+            Console.WriteLine("  .hex           → Auto-decode to XML");
+            Console.WriteLine("  .xml           → Auto-encode to EXI hex");
+            Console.WriteLine("  Other          → Requires --decode or --encode option");
+            Console.WriteLine();
             Console.WriteLine("Pipe Usage:");
             Console.WriteLine("  type file.xml | V2GDecoder.exe --encode        # Pipe XML file to encode");
             Console.WriteLine("  echo \"hex_string\" | V2GDecoder.exe --decode   # Pipe hex string to decode");
             Console.WriteLine();
             Console.WriteLine("Examples:");
-            Console.WriteLine("  V2GDecoder.exe data/dump2.txt                 # Full analysis");
+            Console.WriteLine("  V2GDecoder.exe data/dump2.dump                # Full analysis of hex dump");
+            Console.WriteLine("  V2GDecoder.exe data/test.hex                  # Auto-decode hex to XML");
+            Console.WriteLine("  V2GDecoder.exe data/encode0.xml               # Auto-encode XML to EXI");
             Console.WriteLine("  V2GDecoder.exe -d \"8098021050908C0C0C0E0C5211003200\"  # Decode hex string");
-            Console.WriteLine("  V2GDecoder.exe -d data/dump2.txt              # Extract & decode from file");
+            Console.WriteLine("  V2GDecoder.exe data/test.dat --decode         # Decode unknown file type");
-            Console.WriteLine("  V2GDecoder.exe -e \"<V2G_Message>...</V2G_Message>\"  # Encode XML string");
+            Console.WriteLine("  V2GDecoder.exe data/data0.xml -out data0.hex  # Encode to binary file");
-            Console.WriteLine("  V2GDecoder.exe -e message.xml                 # Encode XML file");
+            Console.WriteLine("  V2GDecoder.exe --decode data.hex -out out.xml # Decode to XML file");
-            Console.WriteLine("  V2GDecoder.exe data/encode0.xml --encode       # Encode XML file to EXI");
+            Console.WriteLine("  type data\\encode0.xml | V2GDecoder.exe -e     # Pipe XML to encode");
-            Console.WriteLine("  V2GDecoder.exe data/dump2.txt --decode         # Decode file to XML only");
+        }
-            Console.WriteLine("  type data\\encode0.xml | V2GDecoder.exe --encode  # Pipe file content to encode");
+        
-            Console.WriteLine("  echo \"8098021050908C0C0C0E0C5211003200\" | V2GDecoder.exe -d  # Pipe hex to decode");
+        static string? GetOutputFilename(string[] args)
+        {
+            for (int i = 0; i < args.Length - 1; i++)
+            {
+                if (args[i].ToLower() == "-out" || args[i].ToLower() == "-o")
+                {
+                    return args[i + 1];
+                }
+            }
+            return null;
         }
         
         static void HandleDecodeCommand(string[] args)
         {
             string input;
             byte[] exiBytes;
+            string? outputFile = GetOutputFilename(args);
             
-            // Check if input is coming from stdin (pipe)
+            // Check if we have sufficient arguments for file/string input
-            if (args.Length < 2)
+            if (args.Length >= 2)
             {
-                if (!Console.IsInputRedirected)
+                // We have command line arguments, use them
-                {
+                input = args[1];
-                    Console.WriteLine("Error: EXI hex string or file required for decode operation");
+            }
-                    Console.WriteLine("Usage: V2GDecoder.exe --decode <exi_hex_string_or_file>");
+            else if (Console.IsInputRedirected)
-                    Console.WriteLine("   or: echo \"hex_string\" | V2GDecoder.exe --decode");
+            {
-                    return;
+                // No sufficient arguments, check if input is coming from stdin (pipe)
-                }
-                
-                // Read from stdin
-                Console.WriteLine("Reading EXI data from stdin (pipe input)...");
                 input = Console.In.ReadToEnd().Trim();
                 if (string.IsNullOrEmpty(input))
                 {
                     Console.WriteLine("Error: No input data received from stdin");
                     return;
                 }
+                outputFile = null; // Force console output for stdin
             }
             else
             {
-                input = args[1];
+                Console.WriteLine("Error: EXI hex string or file required for decode operation");
+                Console.WriteLine("Usage: V2GDecoder.exe --decode <exi_hex_string_or_file> [-out output_file]");
+                return;
             }
             
             // Check if input is a file
             if (File.Exists(input))
             {
-                Console.WriteLine($"Reading EXI data from file: {input}");
-                
                 // Handle different file extensions
                 string extension = Path.GetExtension(input).ToLower();
                 
                 if (extension == ".dump")
                 {
                     // Hex dump file format with arrows (→)
-                    Console.WriteLine("Processing hex dump format file...");
                     byte[] rawData = V2GDecoder.ParseHexFile(input);
                     
                     // Find V2G message in the hex dump
@@ -147,11 +236,9 @@ namespace V2GProtocol
                     if (v2gMessage != null)
                     {
                         exiBytes = v2gMessage;
-                        Console.WriteLine($"Extracted V2G EXI message from hex dump ({exiBytes.Length} bytes).");
                     }
                     else
                     {
-                        Console.WriteLine("Warning: No V2G message header (01 FE) found in hex dump. Attempting to decode raw data.");
                         // Try to decode the raw data directly (might be pure EXI without V2G header)
                         exiBytes = rawData;
                     }
@@ -159,11 +246,9 @@ namespace V2GProtocol
                 else if (extension == ".hex")
                 {
                     // Plain hex file (pure hex string)
-                    Console.WriteLine("Processing hex string file...");
                     string fileContent = File.ReadAllText(input).Trim();
                     fileContent = fileContent.Replace(" ", "").Replace("-", "").Replace("0x", "").Replace("\n", "").Replace("\r", "");
                     exiBytes = Convert.FromHexString(fileContent);
-                    Console.WriteLine($"Parsed hex string from file ({exiBytes.Length} bytes).");
                 }
                 else if (extension == ".txt")
                 {
@@ -172,13 +257,11 @@ namespace V2GProtocol
                     if (fileContent.Contains("→"))
                     {
                         // Hex dump format
-                        Console.WriteLine("Processing legacy hex dump format file...");
                         byte[] rawData = V2GDecoder.ParseHexFile(input);
                         var v2gMessage = ExtractV2GMessageFromHexDump(rawData);
                         if (v2gMessage != null)
                         {
                             exiBytes = v2gMessage;
-                            Console.WriteLine($"Extracted V2G EXI message from hex dump ({exiBytes.Length} bytes).");
                         }
                         else
                         {
@@ -190,13 +273,11 @@ namespace V2GProtocol
                         // Plain hex
                         fileContent = fileContent.Replace(" ", "").Replace("-", "").Replace("0x", "").Replace("\n", "").Replace("\r", "");
                         exiBytes = Convert.FromHexString(fileContent);
-                        Console.WriteLine($"Parsed hex string from file ({exiBytes.Length} bytes).");
                     }
                 }
                 else
                 {
                     // Unknown extension, try as plain hex
-                    Console.WriteLine($"Unknown file extension '{extension}', attempting to parse as hex string...");
                     string fileContent = File.ReadAllText(input).Trim();
                     fileContent = fileContent.Replace(" ", "").Replace("-", "").Replace("0x", "").Replace("\n", "").Replace("\r", "");
                     exiBytes = Convert.FromHexString(fileContent);
@@ -214,18 +295,24 @@ namespace V2GProtocol
                 }
                 
                 exiBytes = Convert.FromHexString(exiHexString);
-                Console.WriteLine("Processing direct hex string input.");
             }
             
             try
             {
-                Console.WriteLine($"Decoding EXI data ({exiBytes.Length} bytes):");
+                // Decode EXI to XML - output only the XML
-                Console.WriteLine($"Input: {Convert.ToHexString(exiBytes)}");
-                Console.WriteLine();
-                
-                // Decode EXI to XML
                 var decodedXml = V2GDecoder.DecodeEXIToXML(exiBytes);
-                Console.WriteLine(decodedXml);
+                
+                if (outputFile != null)
+                {
+                    // Save to file
+                    File.WriteAllText(outputFile, decodedXml);
+                    Console.WriteLine($"Decoded XML saved to: {outputFile}");
+                }
+                else
+                {
+                    // Output to console
+                    Console.WriteLine(decodedXml);
+                }
             }
             catch (Exception ex)
             {
@@ -259,72 +346,63 @@ namespace V2GProtocol
         {
             string xmlInput;
             string xmlContent;
+            string? outputFile = GetOutputFilename(args);
             
-            // Check if input is coming from stdin (pipe)
+            // Check if we have sufficient arguments for file/string input
-            if (args.Length < 2)
+            if (args.Length >= 2)
             {
-                if (!Console.IsInputRedirected)
+                // We have command line arguments, use them
-                {
+                xmlInput = args[1];
-                    Console.WriteLine("Error: XML string or file required for encode operation");
-                    Console.WriteLine("Usage: V2GDecoder.exe --encode <xml_file_or_string>");
-                    Console.WriteLine("   or: type file.xml | V2GDecoder.exe --encode");
-                    return;
-                }
                 
-                // Read from stdin
+                // Check if input is a file
-                Console.WriteLine("Reading XML data from stdin (pipe input)...");
+                if (File.Exists(xmlInput))
+                {
+                    xmlContent = File.ReadAllText(xmlInput);
+                }
+                else
+                {
+                    xmlContent = xmlInput;
+                }
+            }
+            else if (Console.IsInputRedirected)
+            {
+                // No sufficient arguments, check if input is coming from stdin (pipe)
                 xmlContent = Console.In.ReadToEnd().Trim();
                 if (string.IsNullOrEmpty(xmlContent))
                 {
                     Console.WriteLine("Error: No input data received from stdin");
                     return;
                 }
+                outputFile = null; // Force console output for stdin
             }
             else
             {
-                xmlInput = args[1];
+                Console.WriteLine("Error: XML string or file required for encode operation");
-                
+                Console.WriteLine("Usage: V2GDecoder.exe --encode <xml_file_or_string> [-out output_file]");
-                // Check if input is a file
+                return;
-                if (File.Exists(xmlInput))
-                {
-                    string extension = Path.GetExtension(xmlInput).ToLower();
-                    
-                    if (extension == ".xml")
-                    {
-                        Console.WriteLine($"Reading XML from file: {xmlInput}");
-                        xmlContent = File.ReadAllText(xmlInput);
-                    }
-                    else
-                    {
-                        // For non-XML extensions, still try to read as text file
-                        Console.WriteLine($"Reading content from file: {xmlInput} (extension: {extension})");
-                        xmlContent = File.ReadAllText(xmlInput);
-                    }
-                }
-                else
-                {
-                    Console.WriteLine("Processing XML string:");
-                    xmlContent = xmlInput;
-                }
             }
             
             try
             {
-                Console.WriteLine("Input XML:");
-                Console.WriteLine(xmlContent);
-                Console.WriteLine();
-                
                 // Encode XML to EXI
                 var exiBytes = V2GDecoder.EncodeXMLToEXI(xmlContent);
-                var exiHexString = Convert.ToHexString(exiBytes);
                 
-                Console.WriteLine($"Encoded EXI data ({exiBytes.Length} bytes):");
+                if (outputFile != null)
-                Console.WriteLine(exiHexString);
+                {
+                    // Save as binary file
+                    File.WriteAllBytes(outputFile, exiBytes);
+                    Console.WriteLine($"Encoded binary saved to: {outputFile} ({exiBytes.Length} bytes)");
                     
-                // Also show formatted hex
+                    // Also show hex string on console for reference
-                Console.WriteLine();
+                    var exiHexString = Convert.ToHexString(exiBytes);
-                Console.WriteLine("Formatted hex:");
+                    Console.WriteLine($"Hex: {exiHexString}");
-                Console.WriteLine(V2GDecoder.BytesToHex(exiBytes));
+                }
+                else
+                {
+                    // Output hex string to console
+                    var exiHexString = Convert.ToHexString(exiBytes);
+                    Console.WriteLine(exiHexString);
+                }
             }
             catch (Exception ex)
             {

V2GDecoder.cs

@@ -619,13 +619,7 @@ namespace V2GProtocol
             {
                 // 메시지 타입 식별
                 var messageType = IdentifyV2GMessageType(exiPayload);
-                sb.AppendLine($"Identified Message Type: {messageType.Type}");
-                sb.AppendLine($"Message Category: {messageType.Category}");
-                sb.AppendLine($"Message Description: {messageType.Description}");
-                sb.AppendLine();
                 
-                sb.AppendLine("Reconstructed XML from EXI binary:");
-                sb.AppendLine();
                 sb.AppendLine("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
                 sb.AppendLine("<ns1:V2G_Message xmlns:ns1=\"urn:iso:15118:2:2013:MsgDef\" xmlns:ns2=\"urn:iso:15118:2:2013:MsgHeader\" xmlns:ns3=\"urn:iso:15118:2:2013:MsgBody\" xmlns:ns4=\"urn:iso:15118:2:2013:MsgDataTypes\">");
                 
@@ -653,17 +647,11 @@ namespace V2GProtocol
                 
                 sb.AppendLine("  </ns1:Body>");
                 sb.AppendLine("</ns1:V2G_Message>");
-                
-                sb.AppendLine();
-                sb.AppendLine("=== Message Analysis ===");
-                sb.AppendLine($"Message Type: {messageType.Type}");
-                sb.AppendLine($"Session ID: {sessionID}");
-                sb.AppendLine($"Category: {messageType.Category}");
-                sb.AppendLine($"Purpose: {messageType.Description}");
             }
             catch (Exception ex)
             {
-                sb.AppendLine($"Error decoding EXI: {ex.Message}");
+                // In case of error, return error message
+                return $"Error decoding EXI: {ex.Message}";
             }
             
             return sb.ToString();