Develop Reference

Extract files from stream containing zip

I am making a GET request using HttpClient to download a zip file from the internet.
I want to extract all the files contained in the zip file without saving the zip file to disk.
Currently, I am able to download and save the zip file to disk, extract its contents and then delete the zip file from disk. This perfectly fine. However, I want to optimize the process.
I found a way to extract the contents directly from the downloaded zip stream but I have to specify the filenames and extensions.
I am not sure how to extract the contents while preserving their original filenames and extensions without me specifying them.
Current Approach:
string requestUri = "https://www.nuget.org/api/v2/package/" + PackageName + "/" + PackageVersion;
HttpResponseMessage response = await client.GetAsync(requestUri);
response.EnsureSuccessStatusCode();
using Stream PackageStream = await response.Content.ReadAsStreamAsync();
SaveStream($"{DownloadPath}.zip", PackageStream);
ZipFile.ExtractToDirectory($"{DownloadPath}.zip", ExtractPath);
File.Delete($"{DownloadPath}.zip");
// Directly extract Zip contents without saving file and without losing filename and extension
using (ZipArchive archive = new ZipArchive(await response.Content.ReadAsStreamAsync()))
{
foreach (ZipArchiveEntry entry in archive.Entries)
{
using (Stream stream = entry.Open())
{
using (FileStream file = new FileStream("file.txt", FileMode.Create, FileAccess.Write))
{
stream.CopyTo(file);
}
}
}
}
.NET 4.8
.NET Core 3.1
C# 8.0
Any help in this regards would be appreciated.
Please feel free to comment on alternative approaches or suggestions.
Thank you in advance.

ZipArchiveEntry has a Name and FullName property that can be used to get the names of the files within the archive while preserving their original filenames and extensions
The FullName property contains the relative path, including the subdirectory hierarchy, of an entry in a zip archive. (In contrast, the Name property contains only the name of the entry and does not include the subdirectory hierarchy.)
For example
using (ZipArchive archive = new ZipArchive(await response.Content.ReadAsStreamAsync())) {
foreach (ZipArchiveEntry entry in archive.Entries) {
using (Stream stream = entry.Open()) {
string destination = Path.GetFullPath(Path.Combine(downloadPath, entry.FullName));
var directory = Path.GetDirectoryName(destination);
if (!Directory.Exists(directory))
Directory.CreateDirectory(directory);
using (FileStream file = new FileStream(destination, FileMode.Create, FileAccess.Write)) {
await stream.CopyToAsync(file);
}
}
}
}
will extract the files in the same subdirectory hierarchy as they were stored in the archive while if entry.Name was used, all the files would be extracted to the same location.

Upload Csv to solution explorer

I'm trying to build an application in which a user can upload a csv file and convert it into XML. Currently my controller can create .txt file in a temp folder. However when I open the txt file it comes out all corrupted as below:
I have two questions
1. How can I make it so that the file displays properly i.e. as items separated by commas?
2. How can I change my code to make the file upload into my solution explorer
Here is the relevant controller code:
[HttpPost("UploadFiles")]
public async Task<IActionResult> FileUpload(List<IFormFile> files)
{
long size = files.Sum(f => f.Length);
var filePaths = new List<string>();
foreach (var formFile in files)
{
if(formFile.Length > 0)
{
var filePath = Path.GetTempPath()+ Guid.NewGuid().ToString()+".txt";
filePaths.Add(filePath);
using (var stream = new FileStream(filePath, FileMode.Create, FileAccess.ReadWrite))
{
await formFile.CopyToAsync(stream);
}
}
}
return Ok(new { count = files.Count, size, filePaths });
}
Any suggestions would be much appreciated
Thanks in advance

When the file is corrupt I think the conversion doesn't work. Try for now uploading it without any conversion.
For the second question you can do the following
var filePath = Path.Combine(AppContext.BaseDirectory, $"{Guid.NewGuid().ToString()}.csv"); // or whatever extension you are actually having without modifying the original extension
This will store the file either in the "bin" directory path or in the directory where the source-code is located.

Compressing Files With C# By Winrar

I never done this but I am develping a simple application and really need some help.
The scenario is that I have some excel files which are all name coded, I need to get the first 5 letters of each files and compress those together. Ex.
MARKS
MARKS 2
MARKS 3
These all compress.
Is their any method to do this and zip with winrar.
Thanks

I agree IonicZip (now dotnetzip) is good. here is the sample of what you want to do
string somepath = "D:\\ExcelFiles";
string zippath = "D:\\ExcelFiles\\some.zip";
string[] filenames =
System.IO.Directory.GetFiles(somepath, "Mark*.xlsx", SearchOption.AllDirectories);
using (ZipFile zip = new ZipFile())
{
foreach (String filename in filenames)
{
ZipEntry e = zip.AddFile(filename, "");
}
zip.Save(zippath);
}

I use Ionic Zip in my project. API call is very easy. You can simply zip your files.
using (ZipFile zip = new ZipFile())
{
// add this map file into the "images" directory in the zip archive
zip.AddFile(#"C:\Users\kth\Desktop\dll\MARKS.xl", "images");
zip.Save("MyZipFile.zip");
}

How to open up a zip file from MemoryStream

I am using DotNetZip.
What I need to do is to open up a zip files with files from the server.
The user can then grab the files and store it locally on their machine.
What I did before was the following:
string path = "Q:\\ZipFiles\\zip" + npnum + ".zip";
zip.Save(path);
Process.Start(path);
Note that Q: is a drive on the server. With Process.Start, it simply open up the zip file so that the user can access all the files. I like to do the same but not store the file on disk but show it from memory.
Now, instead of storing the zip file on the server, I like to open it up with MemoryStream
I have the following but does not seem to work
var ms = new MemoryStream();
zip.Save(ms);
but not sure how to proceed further in terms of opening up the zip file from a memory stream so that the user can access all the files

Here is a live piece of code (copied verbatim) which I wrote to download a series of blog posts as a zipped csv file. It's live and it works.
public ActionResult L2CSV()
{
var posts = _dataItemService.SelectStuff();
string csv = CSV.IEnumerableToCSV(posts);
// These first two lines simply get our required data as a long csv string
var fileData = Zip.CreateZip("LogPosts.csv", System.Text.Encoding.UTF8.GetBytes(csv));
var cd = new System.Net.Mime.ContentDisposition
{
FileName = "LogPosts.zip",
// always prompt the user for downloading, set to true if you want
// the browser to try to show the file inline
Inline = false,
};
Response.AppendHeader("Content-Disposition", cd.ToString());
return File(fileData, "application/octet-stream");
}

You can use:
zip.Save(ms);
// Set read point to beginning of stream
ms.Position = 0;
ZipFile newZip = ZipFile.Read(ms);

See the documentation for Create a zip using content obtained from a stream.
using (ZipFile zip = new ZipFile())
{
ZipEntry e= zip.AddEntry("Content-From-Stream.bin", "basedirectory", StreamToRead);
e.Comment = "The content for entry in the zip file was obtained from a stream";
zip.AddFile("Readme.txt");
zip.Save(zipFileToCreate);
}
After saving it, you can then open it up as normal.

How to read data from a zip file without having to unzip the entire file

Is there anyway in .Net (C#) to extract data from a zip file without decompressing the complete file?
I possibly want to extract data (file) from the start of a zip file if the compression algorithm compress the file used was in a deterministic order.

With .Net Framework 4.5 (using ZipArchive):
using (ZipArchive zip = ZipFile.Open(zipfile, ZipArchiveMode.Read))
foreach (ZipArchiveEntry entry in zip.Entries)
if(entry.Name == "myfile")
entry.ExtractToFile("myfile");
Find "myfile" in zipfile and extract it.

DotNetZip is your friend here.
As easy as:
using (ZipFile zip = ZipFile.Read(ExistingZipFile))
{
ZipEntry e = zip["MyReport.doc"];
e.Extract(OutputStream);
}
(you can also extract to a file or other destinations).
Reading the zip file's table of contents is as easy as:
using (ZipFile zip = ZipFile.Read(ExistingZipFile))
{
foreach (ZipEntry e in zip)
{
if (header)
{
System.Console.WriteLine("Zipfile: {0}", zip.Name);
if ((zip.Comment != null) && (zip.Comment != ""))
System.Console.WriteLine("Comment: {0}", zip.Comment);
System.Console.WriteLine("\n{1,-22} {2,8} {3,5} {4,8} {5,3} {0}",
"Filename", "Modified", "Size", "Ratio", "Packed", "pw?");
System.Console.WriteLine(new System.String('-', 72));
header = false;
}
System.Console.WriteLine("{1,-22} {2,8} {3,5:F0}% {4,8} {5,3} {0}",
e.FileName,
e.LastModified.ToString("yyyy-MM-dd HH:mm:ss"),
e.UncompressedSize,
e.CompressionRatio,
e.CompressedSize,
(e.UsesEncryption) ? "Y" : "N");
}
}
Edited To Note: DotNetZip used to live at Codeplex. Codeplex has been shut down. The old archive is still available at Codeplex. It looks like the code has migrated to Github:
https://github.com/DinoChiesa/DotNetZip. Looks to be the original author's repo.
https://github.com/haf/DotNetZip.Semverd. This looks to be the currently maintained version. It's also packaged up an available via Nuget at https://www.nuget.org/packages/DotNetZip/

Something like this will list and extract the files one by one, if you want to use SharpZipLib:
var zip = new ZipInputStream(File.OpenRead(#"C:\Users\Javi\Desktop\myzip.zip"));
var filestream = new FileStream(#"C:\Users\Javi\Desktop\myzip.zip", FileMode.Open, FileAccess.Read);
ZipFile zipfile = new ZipFile(filestream);
ZipEntry item;
while ((item = zip.GetNextEntry()) != null)
{
Console.WriteLine(item.Name);
using (StreamReader s = new StreamReader(zipfile.GetInputStream(item)))
{
// stream with the file
Console.WriteLine(s.ReadToEnd());
}
}
Based on this example: content inside zip file

Here is how a UTF8 text file can be read from a zip archive into a string variable (.NET Framework 4.5 and up):
string zipFileFullPath = "{{TypeYourZipFileFullPathHere}}";
string targetFileName = "{{TypeYourTargetFileNameHere}}";
string text = new string(
(new System.IO.StreamReader(
System.IO.Compression.ZipFile.OpenRead(zipFileFullPath)
.Entries.Where(x => x.Name.Equals(targetFileName,
StringComparison.InvariantCulture))
.FirstOrDefault()
.Open(), Encoding.UTF8)
.ReadToEnd())
.ToArray());

the following code can read specific file as byte array :
using ZipArchive zipArchive = ZipFile.OpenRead(zipFilePath);
foreach(ZipArchiveEntry zipArchiveEntry in zipArchive.Entries)
{
if(zipArchiveEntry.Name.Equals(fileName,StringComparison.OrdinalIgnoreCase))
{
Stream stream = zipArchiveEntry.Open();
using MemoryStream memoryStream = new MemoryStream();
await stream.CopyToAsync(memoryStream);
return memoryStream.ToArray();
}
}

Zip files have a table of contents. Every zip utility should have the ability to query just the TOC. Or you can use a command line program like 7zip -t to print the table of contents and redirect it to a text file.

In such case you will need to parse zip local header entries. Each file, stored in zip file, has preceding Local File Header entry, which (normally) contains enough information for decompression, Generally, you can make simple parsing of such entries in stream, select needed file, copy header + compressed file data to other file, and call unzip on that part (if you don't want to deal with the whole Zip decompression code or library).