TarTarSource.cs

using System;
using System.IO;
using System.Text;

namespace TarGZImporter;

public static class TarTarSource
{
    public struct TarEntry
    {
        public string Name;
        public byte[] Data;
    }
    
    public static TarEntry ReadTarEntry(Stream fs)
    {
        var entry = new TarEntry();

        // Read 200 bytes for the header
        var header = new byte[0x200];
        var bytesRead = fs.Read(header, 0, 0x200);

        // Get the name and size of the file
        entry.Name = Encoding.ASCII.GetString(header, 0, 100).Replace('\0', ' ').Trim();
        if (string.IsNullOrEmpty(entry.Name))
            return entry;

        // Skip 24 bytes and read 12 for the size string from the header (octal)
        var size = Encoding.ASCII.GetString(header, 124, 12).Replace('\0', ' ').Trim();
        var sizeInt = Convert.ToInt32(size, 8);

        // Round size up to the nearest 512 bytes
        var sizeRounded = (sizeInt + 511) & ~511;

        entry.Data = new byte[sizeRounded];
        bytesRead = fs.Read(entry.Data, 0, sizeRounded);

        return entry;
    }
}