Create a TAR archive, using a list of type string, containing an XML

[rzamurianos]

Hello, I have a list of type string, each of these strings has an XML format. Each string in the list is an XML file. The goal is to create a TAR file that contains all the strings.
I have this code:

private byte[] GET_FileTAR_With_List(List<string> lstInvoiceXML, string Language)
{
    byte[] byteArray = null;
    try
    {
        string stringXML = "";
        int i = 0;
        MemoryStream outputMemStream = new MemoryStream();
        TarOutputStream tarOut = new TarOutputStream(outputMemStream);
        foreach (var eInvoiceXML in lstInvoiceXML)
        {
            i += 1;
            MemoryStream msFormXml = new MemoryStream(Encoding.UTF8.GetBytes(eInvoiceXML.ToString()));
            TarEntry entry = TarEntry.CreateTarEntry("File" + i + ".XML");
            entry.Size = msFormXml.Length;
            tarOut.PutNextEntry(entry);
            ICSharpCode.SharpZipLib.Core.StreamUtils.Copy(msFormXml, tarOut, new byte[4096]);
            tarOut.CloseEntry();
            msFormXml.Close();
        }
        tarOut.Close();
        byteArray = outputMemStream.ToArray();
        return byteArray;
    }
    catch (Exception ex)
    {
        RecordLog(ex.Message, "GenerarFacturaVentaXMLPorPaquete", "BLSALDServiceInvoicePackage", "ES");
        return byteArray;
    }
}

The error message when decompressing is: "There are no files in the TAR".
Any ideas, what am I doing wrong?

[piksel]

I don't see anything that would suggest it shouldn't work. Are you sure your list is not empty?

I made this PoC from your code snippet:

using System;
using System.Text;
using System.IO;
using System.Collections.Generic;
using ICSharpCode.SharpZipLib.Tar;

var res = GET_FileTAR_With_List(new List<string> {
    "This is a content",
    "I am also a content",
    "Me three"
}, "");
var len = File.WriteAllBytes("output.tar", res);
Console.WriteLine($"Wrote {len} bytes(s)!");

byte[] GET_FileTAR_With_List(List<string> lstInvoiceXML, string Language)
{
    byte[] byteArray = null;
    try
    {
        string stringXML = "";
        int i = 0;
        MemoryStream outputMemStream = new MemoryStream();
        TarOutputStream tarOut = new TarOutputStream(outputMemStream);
        foreach (var eInvoiceXML in lstInvoiceXML)
        {
            i += 1;
            MemoryStream msFormXml = new MemoryStream(Encoding.UTF8.GetBytes(eInvoiceXML.ToString()));
            TarEntry entry = TarEntry.CreateTarEntry("File" + i + ".XML");
            entry.Size = msFormXml.Length;
            tarOut.PutNextEntry(entry);
            ICSharpCode.SharpZipLib.Core.StreamUtils.Copy(msFormXml, tarOut, new byte[4096]);
            tarOut.CloseEntry();
            msFormXml.Close();
        }
        tarOut.Close();
        byteArray = outputMemStream.ToArray();
        return byteArray;
    }
    catch (Exception ex)
    {
        RecordLog(ex.Message, "GenerarFacturaVentaXMLPorPaquete", "BLSALDServiceInvoicePackage", "ES");
        return byteArray;
    }
}

void RecordLog(string msg, string g1, string g2, string g3) {
    Console.WriteLine($"[{g1}][{g2}][{g3}] {msg}");
}

It produced the following file:

❯ dotnet run
/tmp/szl-761/Program.cs(23,34): warning CS0618: 'TarOutputStream.TarOutputStream(Stream)' is obsolete: 'No Encoding for Name field is specified, any non-ASCII bytes will be discarded' [/tmp/szl-761/szl-761.csproj]
/tmp/szl-761/Program.cs(20,16): warning CS0219: The variable 'stringXML' is assigned but its value is never used [/tmp/szl-761/szl-761.csproj]
Wrote 10240 bytes(s)!

/tmp/szl-761 .NET v5.0.402 🎯 net5.0
❯ tar -tvf output.tar
-rwx------ 0/0              17 2022-07-20 11:57 File1.XML
-rwx------ 0/0              19 2022-07-20 11:57 File2.XML
-rwx------ 0/0               8 2022-07-20 11:57 File3.XML