Unzip files programmatically in .net

Petteri Source

I am trying to programatically unzip a zipped file.

I have tried using the System.IO.Compression.GZipStream class in .NET, but when my app runs (actually a unit test) I get this exception:

System.IO.InvalidDataException: The magic number in GZip header is not correct. Make sure you are passing in a GZip stream..

I now realize that a .zip file is not the same as a .gz file, and that GZip is not the same as Zip.

However, since I'm able to extract the file by manually double clicking the zipped file and then clicking the "Extract all files"-button, I think there should be a way of doing that in code as well.

Therefore I've tried to use Process.Start() with the path to the zipped file as input. This causes my app to open a Window showing the contents in the zipped file. That's all fine, but the app will be installed on a server with none around to click the "Extract all files"-button.

So, how do I get my app to extract the files in the zipped files?

Or is there another way to do it? I prefer doing it in code, without downloading any third party libraries or apps; the security department ain't too fancy about that...

c#unzip

Answers

answered 9 years ago Sam Axe #1

Use the DotNetZip library at http://www.codeplex.com/DotNetZip

class library and toolset for manipulating zip files. Use VB, C# or any .NET language to easily create, extract, or update zip files...

DotNetZip works on PCs with the full .NET Framework, and also runs on mobile devices that use the .NET Compact Framework. Create and read zip files in VB, C#, or any .NET language, or any scripting environment...

If all you want is a better DeflateStream or GZipStream class to replace the one that is built-into the .NET BCL, DotNetZip has that, too. DotNetZip's DeflateStream and GZipStream are available in a standalone assembly, based on a .NET port of Zlib. These streams support compression levels and deliver much better performance than the built-in classes. There is also a ZlibStream to complete the set (RFC 1950, 1951, 1952)...

answered 9 years ago Kenneth Cochran #2

Standard zip files normally use the deflate algorithm.

To extract files without using third party libraries use DeflateStream. You'll need a bit more information about the zip file archive format as Microsoft only provides the compression algorithm.

You may also try using zipfldr.dll. It is Microsoft's compression library (compressed folders from the Send to menu). It appears to be a com library but it's undocumented. You may be able to get it working for you through experimentation.

answered 9 years ago RedWolves #3

From here :

Compressed GZipStream objects written to a file with an extension of .gz can be decompressed using many common compression tools; however, this class does not inherently provide functionality for adding files to or extracting files from .zip archives.

answered 9 years ago Chris Conway #4

We have used SharpZipLib successfully on many projects. I know it's a third party tool, but source code is included and could provide some insight if you chose to reinvent the wheel here.

answered 6 years ago Lukas #5

Free, and no external DLL files. Everything is in one CS file. One download is just the CS file, another download is a very easy to understand example. Just tried it today and I can't believe how simple the setup was. It worked on first try, no errors, no nothing.

https://github.com/jaime-olivares/zipstorer

answered 6 years ago bsara #6

With .NET 4.5 you can now unzip files using the .NET framework:

using System;
using System.IO;

namespace ConsoleApplication
{
  class Program
  {
    static void Main(string[] args)
    {
      string startPath = @"c:\example\start";
      string zipPath = @"c:\example\result.zip";
      string extractPath = @"c:\example\extract";

      System.IO.Compression.ZipFile.CreateFromDirectory(startPath, zipPath);
      System.IO.Compression.ZipFile.ExtractToDirectory(zipPath, extractPath);
    }
  }
}

The above code was taken directly from Microsoft's documentation: http://msdn.microsoft.com/en-us/library/ms404280(v=vs.110).aspx

ZipFile is contained in the assembly System.IO.Compression.FileSystem. (Thanks nateirvin...see comment below)

answered 5 years ago Phyllip Hamby #7

I use this to either zip or unzip multiple files. The Regex stuff is not required, but I use it to change the date stamp and remove unwanted underscores. I use the empty string in the Compress >> zipPath string to prefix something to all files if required. Also, I usually comment out either Compress() or Decompress() based on what I am doing.

using System;
using System.IO.Compression;
using System.IO;
using System.Text.RegularExpressions;

namespace ZipAndUnzip
{
    class Program
    {
        static void Main(string[] args)
        {
            var directoryPath = new DirectoryInfo(@"C:\your_path\");

            Compress(directoryPath);
            Decompress(directoryPath);
        }

        public static void Compress(DirectoryInfo directoryPath)
        {
            foreach (DirectoryInfo directory in directoryPath.GetDirectories())
            {
                var path = directoryPath.FullName;
                var newArchiveName = Regex.Replace(directory.Name, "[0-9]{8}", "20130913");
                newArchiveName = Regex.Replace(newArchiveName, "[_]+", "_");
                string startPath = path + directory.Name;
                string zipPath = path + "" + newArchiveName + ".zip";

                ZipFile.CreateFromDirectory(startPath, zipPath);
            }

        }

        public static void Decompress(DirectoryInfo directoryPath)
        {
            foreach (FileInfo file in directoryPath.GetFiles())
            {
                var path = directoryPath.FullName;
                string zipPath = path + file.Name;
                string extractPath = Regex.Replace(path + file.Name, ".zip", "");

                ZipFile.ExtractToDirectory(zipPath, extractPath);
            }
        }


    }
}

answered 5 years ago Per Lundberg #8

I found out about this one (Unzip package on NuGet) today, since I ran into a hard bug in DotNetZip, and I realized there hasn't been really that much work done on DotNetZip for the last two years.

The Unzip package is lean, and it did the job for me - it didn't have the bug that DotNetZip had. Also, it was a reasonably small file, relying upon the Microsoft BCL for the actual decompression. I could easily make adjustments which I needed (to be able to keep track of the progress while decompressing). I recommend it.

answered 4 years ago Michael Blake #9

You can do it all within .NET 3.5 using DeflateStream. The thing lacking in .NET 3.5 is the ability to process the file header sections that are used to organize the zipped files. PKWare has published this information, which you can use to process the zip file after you create the structures that are used. It is not particularly onerous, and it a good practice in tool building without using 3rd party code.

It isn't a one line answer, but it is completely doable if you are willing and able to take the time yourself. I wrote a class to do this in a couple of hours and what I got from that is the ability to zip and unzip files using .NET 3.5 only.

answered 3 years ago Mister Epic #10

For .Net 4.5+

It is not always desired to write the uncompressed file to disk. As an ASP.Net developer, I would have to fiddle with permissions to grant rights for my application to write to the filesystem. By working with streams in memory, I can sidestep all that and read the files directly:

using (ZipArchive archive = new ZipArchive(postedZipStream))
{
    foreach (ZipArchiveEntry entry in archive.Entries)
    {
         var stream = entry.Open();
         //Do awesome stream stuff!!
    }
}

Alternatively, you can still write the decompressed file out to disk by calling ExtractToFile():

using (ZipArchive archive = ZipFile.OpenRead(pathToZip))
{
    foreach (ZipArchiveEntry entry in archive.Entries)
    {
        entry.ExtractToFile(Path.Combine(destination, entry.FullName));
    }
} 

To use the ZipArchive class, you will need to add a reference to the System.IO.Compression namespace.

answered 3 years ago Steve Rousseau #11

From Embed Ressources:

using (Stream _pluginZipResourceStream = Assembly.GetExecutingAssembly().GetManifestResourceStream(programName + "." + "filename.zip"))
{
    using (ZipArchive zip = new ZipArchive(_pluginZipResourceStream))
    {
        zip.ExtractToDirectory(Application.StartupPath);
    }
}

answered 1 year ago Răzvan Bălan #12

Until now, I was using cmd processes in order to extract an .iso file, copy it into a temporary path from server and extracted on a usb stick. Recently I've found that this is working perfectly with .iso's that are less than 10Gb. For a iso like 29Gb this method gets stuck somehow.

    public void ExtractArchive()
    {
        try
        {

            try
            {
                Directory.Delete(copyISOLocation.OutputPath, true); 
            }
            catch (Exception e) when (e is IOException || e is UnauthorizedAccessException)
            {
            }

            Process cmd = new Process();
            cmd.StartInfo.FileName = "cmd.exe";
            cmd.StartInfo.RedirectStandardInput = true;
            cmd.StartInfo.RedirectStandardOutput = true;
            cmd.StartInfo.CreateNoWindow = true;
            cmd.StartInfo.UseShellExecute = false;
            cmd.StartInfo.WindowStyle = ProcessWindowStyle.Normal;

            //stackoverflow
            cmd.StartInfo.Arguments = "-R";

            cmd.Disposed += (sender, args) => {
                Console.WriteLine("CMD Process disposed");
            };
            cmd.Exited += (sender, args) => {
                Console.WriteLine("CMD Process exited");
            };
            cmd.ErrorDataReceived += (sender, args) => {
                Console.WriteLine("CMD Process error data received");
                Console.WriteLine(args.Data);
            };
            cmd.OutputDataReceived += (sender, args) => {
                Console.WriteLine("CMD Process Output data received");
                Console.WriteLine(args.Data);
            };

            //stackoverflow


            cmd.Start();

            cmd.StandardInput.WriteLine("C:");
            //Console.WriteLine(cmd.StandardOutput.Read());
            cmd.StandardInput.Flush();

            cmd.StandardInput.WriteLine("cd C:\\\"Program Files (x86)\"\\7-Zip\\");
            //Console.WriteLine(cmd.StandardOutput.ReadToEnd());
            cmd.StandardInput.Flush();

            cmd.StandardInput.WriteLine(string.Format("7z.exe x -o{0} {1}", copyISOLocation.OutputPath, copyISOLocation.TempIsoPath));
            //Console.WriteLine(cmd.StandardOutput.ReadToEnd());
            cmd.StandardInput.Flush();
            cmd.StandardInput.Close();
            cmd.WaitForExit();
            Console.WriteLine(cmd.StandardOutput.ReadToEnd());
            Console.WriteLine(cmd.StandardError.ReadToEnd());

answered 12 months ago Mahadev Mane #13

String ZipPath = @"c:\my\data.zip";
String extractPath = @"d:\\myunzips";
ZipFile.ExtractToDirectory(ZipPath, extractPath);

To use the ZipFile class, you must add a reference to the System.IO.Compression.FileSystem assembly in your project

answered 2 months ago Arun kumar #14

you can use Info-unzip command line cod.you only need to download unzip.exe from Info-unzip official website.

 internal static void Unzip(string sorcefile)
    {
        try
        {
            AFolderFiles.AFolderFilesDelete.DeleteFolder(TempBackupFolder); // delete old folder   
            AFolderFiles.AFolderFilesCreate.CreateIfNotExist(TempBackupFolder); // delete old folder   
           //need to Command command also to export attributes to a excel file
            System.Diagnostics.Process process = new System.Diagnostics.Process();
            System.Diagnostics.ProcessStartInfo startInfo = new System.Diagnostics.ProcessStartInfo();
            startInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden; // window type
            startInfo.FileName = UnzipExe;
            startInfo.Arguments = sorcefile + " -d " + TempBackupFolder;
            process.StartInfo = startInfo;
            process.Start();
            //string result = process.StandardOutput.ReadToEnd();
            process.WaitForExit();
            process.Dispose();
            process.Close();
        }
        catch (Exception ex){ throw ex; }
    }        

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