Develop Reference

Copy a file from address byte to address byte

I was looking around for a way to copy a portion of a file from a determined address to another address, is there a way to do that in C#?
For example let's say i have a file like this:
and I want to copy from 0xA0 to 0xB0 and then paste it to another file.

Something like this perhaps:
long start = 0xA0;
int length = 0xB0 - start;
byte[] data = new byte[length];
using (FileStream fs = File.OpenRead(#"C:\Temp\InputFile.txt"))
{
fs.Seek(start, SeekOrigin.Begin);
fs.Read(data, 0, length);
}
File.WriteAllBytes(#"C:\Temp\OutputFile.txt", data);

It should be something like:
// input data
string inputName = "input.bin";
long startInput = 0xa0;
long endInput = 0xb0; // excluding 0xb0 that is not copied
string outputName = "output.bin";
long startOutput = 0xa0;
// begin of code
long count = endInput - startInput;
using (var fs = File.OpenRead(inputName))
using (var fs2 = File.OpenWrite(outputName))
{
fs.Seek(startInput, SeekOrigin.Begin);
fs2.Seek(startOutput, SeekOrigin.Begin);
byte[] buf = new byte[4096];
while (count > 0)
{
int read = fs.Read(buf, 0, (int)Math.Min(buf.Length, count));
if (read == 0)
{
// end of file encountered
throw new IOException("end of file encountered");
}
fs2.Write(buf, 0, read);
count -= read;
}
}

How to split file into parts and download

I'm working on a split downloader for c#. It is downloading fine (so the logic is working) but the problem is that whatever file it downloads it corrupts. I have no idea on how to fix it. Here's the code:
private void mergeClean()
{
const int chunkSize = 1 * 1024; // 2KB
using (var output = File.Create("output.jpg"))
{
foreach (var file in Files)
{
using (var input = File.OpenRead(file))
{
var buffer = new byte[chunkSize];
int bytesRead;
while ((bytesRead = input.Read(buffer, 0, buffer.Length)) > 0)
{
output.Write(buffer, 0, bytesRead);
}
}
}
}
foreach (var file in Files)
{
File.Delete(file);
}
}
private void SaveFileStream(String path, Stream stream)
{
var fileStream = new FileStream(path, FileMode.Create, FileAccess.Write);
stream.CopyTo(fileStream);
fileStream.Dispose();
}
public void SplitDownload(string URL)
{
System.Net.WebRequest req = System.Net.HttpWebRequest.Create(URL);
req.Method = "HEAD";
System.Net.WebResponse resp = req.GetResponse();
var responseLength = double.Parse(resp.Headers.Get("Content-Length"));
var partSize = Math.Ceiling(responseLength / 10);
var previous = 0;
for (int i = (int)partSize; i <= responseLength; i = i + (int)partSize)
{
Thread t = new Thread(() => Download(URL, previous, i));
t.Start();
t.Join();
previous = i;
}
mergeClean();
}
private void Download(string URL, int Start, int End)
{
Console.WriteLine(String.Format("{0},{1}", Start, End));
HttpWebRequest myHttpWebRequest = (HttpWebRequest)WebRequest.Create(URL);
myHttpWebRequest.AddRange(Start, End);
HttpWebResponse myHttpWebResponse = (HttpWebResponse)myHttpWebRequest.GetResponse();
Stream streamResponse = myHttpWebResponse.GetResponseStream();
String name = GenerateTempName();
SaveFileStream(name, streamResponse);
Files.Add(name);
}
Here is an example of what it does:
UPDATED CODE:
static string GenerateTempName(int start)
{
String name = String.Format("{0:D6}.tmp", start);
return name;
}
static public List<string> Files = new List<string>();
static private void mergeClean()
{
Files.Sort();
const int chunkSize = 1 * 1024; // 2KB
using (var output = File.Create("output.jpg"))
{
foreach (var file in Files)
{
using (var input = File.OpenRead(file))
{
var buffer = new byte[chunkSize];
int bytesRead;
while ((bytesRead = input.Read(buffer, 0, buffer.Length)) > 0)
{
output.Write(buffer, 0, bytesRead);
}
}
}
}
foreach (var file in Files)
{
File.Delete(file);
}
}

You need to recombine file from pieces in correct order - current code create random file names and even if items are added to list of files they are added in random order due to unpredictable time when segment download finishes.
Possible fix: use block start offset as part of the file name String name = String.Format("file{0:D6}.tmp", Start) and sort files by name before combining them back.
Note that {0:D6} formatting is used to pad index with 0 to allow sorting by name to be easier and avoid need for natural sort code.

overwrite file in Zipping

I try to Zip some .pdf files in C#. My code works fine but when the size of one of the pdfs is big, it is going to overwrite that pdf on the rest of pdfs. I am not sure what is happening. I tried to increase the size of buffer or zip file but still same issue. Do you have any suggestion?
This is my code:
public void ProcessZipRequest(string strQueueID, string strBatchID, string strFtpPath)
{
int intReportCnt = 0;
string strZipFileName = "Order-" + strBatchID + "-" + strQueueID + "-" + DateTime.Now.ToString("MM-dd-yyyy-HH-mm") + ".zip";
strZipFileName = SafeFileName(strZipFileName);
//MemoryStream ms = new MemoryStream();
FileStream ms = new FileStream(#"c:\surf\nikoo.zip", FileMode.Create);
ZipOutputStream oZipStream = new ZipOutputStream(ms); // create zip stream
oZipStream.SetLevel(9); // maximum compression
intReportCnt += 1;
string strRptFilename=string.Empty;
MemoryStream outputStream = new MemoryStream();
if (strQueueID != null)
{
String[] filenames = Directory.GetFiles(#"C:\uploaded");
// setting Report name to path given for Report name
foreach (String filename in filenames)
{
strRptFilename = filename.Substring(filename.LastIndexOf("\\") + 1);
FileStream fs = File.OpenRead(#"C:\uploaded\" + strRptFilename);
int bufferSize = 2048;
int readCount;
byte[] buffer = new byte[bufferSize];
readCount = fs.Read(buffer, 0, bufferSize);
while (readCount>0)
{
outputStream.Write(buffer, 0, readCount);
readCount = fs.Read(buffer, 0, bufferSize);
}
fs.Close();
outputStream.Position = 0;
ZipFile(ref outputStream, strRptFilename, ref oZipStream);
}
}
outputStream.Close();
oZipStream.Finish();
oZipStream.Flush();
oZipStream.IsStreamOwner = false; // False stops the Close also Closing the underlying stream.
oZipStream.Close(); // Must finish the ZipOutputStream before using outputMemStream.
ms.Close();
}
And this is Zipfile Method:
public void ZipFile(ref MemoryStream msFile, string strFilename, ref ZipOutputStream oZipStream)
{
ZipEntry oZipEntry = new ZipEntry(strFilename);
oZipEntry.DateTime = DateTime.Now;
oZipEntry.Size = msFile.Length;
oZipStream.PutNextEntry(oZipEntry);
StreamUtils.Copy(msFile, oZipStream, new byte[4096]);
oZipStream.CloseEntry();
}

I found the issue. I have to create a new MemoyStream in for loop and close it at the end of the loop.
foreach (String filename in filenames)
{
strRptFilename = filename.Substring(filename.LastIndexOf("\\") + 1);
outputStream = new MemoryStream();
FileStream fs = File.OpenRead(#"C:\uploaded\" + strRptFilename);
int bufferSize = 2048;
int readCount;
byte[] buffer = new byte[bufferSize];
readCount = fs.Read(buffer, 0, bufferSize);
while (readCount>0)
{
outputStream.Write(buffer, 0, readCount);
readCount = fs.Read(buffer, 0, bufferSize);
}
fs.Close();
outputStream.Position = 0;
ZipFile(ref outputStream, strRptFilename, ref oZipStream);
fs.Close();
outputStream.Close();
}

decompress a .gz file using GZipStream

I have several .gz files, and I want to decompress them one by one.
I have writen a simple code using GzipStream in C#, but got failed. I wonder a correct and useful method to achieve what I want. Thanks a lot.
private string Extrgz(string infile)
{
string dir = Path.GetDirectoryName(infile);
string decompressionFileName = dir + Path.GetFileNameWithoutExtension(infile) + "_decompression.bin";
using (GZipStream instream = new GZipStream(File.OpenRead(infile), CompressionMode.Compress))// ArgumentException...
{
using (FileStream outputStream = new FileStream(decompressionFileName, FileMode.Append, FileAccess.Write))
{
int bufferSize = 8192, bytesRead = 0;
byte[] buffer = new byte[bufferSize];
while ((bytesRead = instream.Read(buffer, 0, bufferSize)) > 0)
{
outputStream.Write(buffer, 0, bytesRead);
}
}
}
return decompressionFileName;
}

You need to decompress but you set CompressionMode.Compress, replace it with CompressionMode.Decompress.
Example here.

Here:
public static void DeCompressFile(string CompressedFile, string DeCompressedFile)
{
byte[] buffer = new byte[1024 * 1024];
using (System.IO.FileStream fstrmCompressedFile = System.IO.File.OpenRead(CompressedFile)) // fi.OpenRead())
{
using (System.IO.FileStream fstrmDecompressedFile = System.IO.File.Create(DeCompressedFile))
{
using (System.IO.Compression.GZipStream strmUncompress = new System.IO.Compression.GZipStream(fstrmCompressedFile,
System.IO.Compression.CompressionMode.Decompress))
{
int numRead = strmUncompress.Read(buffer, 0, buffer.Length);
while (numRead != 0)
{
fstrmDecompressedFile.Write(buffer, 0, numRead);
fstrmDecompressedFile.Flush();
numRead = strmUncompress.Read(buffer, 0, buffer.Length);
} // Whend
//int numRead = 0;
//while ((numRead = strmUncompress.Read(buffer, 0, buffer.Length)) != 0)
//{
// fstrmDecompressedFile.Write(buffer, 0, numRead);
// fstrmDecompressedFile.Flush();
//} // Whend
strmUncompress.Close();
} // End Using System.IO.Compression.GZipStream strmUncompress
fstrmDecompressedFile.Flush();
fstrmDecompressedFile.Close();
} // End Using System.IO.FileStream fstrmCompressedFile
fstrmCompressedFile.Close();
} // End Using System.IO.FileStream fstrmCompressedFile
} // End Sub DeCompressFile
// http://www.dotnetperls.com/decompress
public static byte[] Decompress(byte[] gzip)
{
byte[] baRetVal = null;
using (System.IO.MemoryStream ByteStream = new System.IO.MemoryStream(gzip))
{
// Create a GZIP stream with decompression mode.
// ... Then create a buffer and write into while reading from the GZIP stream.
using (System.IO.Compression.GZipStream stream = new System.IO.Compression.GZipStream(ByteStream
, System.IO.Compression.CompressionMode.Decompress))
{
const int size = 4096;
byte[] buffer = new byte[size];
using (System.IO.MemoryStream memory = new System.IO.MemoryStream())
{
int count = 0;
count = stream.Read(buffer, 0, size);
while (count > 0)
{
memory.Write(buffer, 0, count);
memory.Flush();
count = stream.Read(buffer, 0, size);
}
baRetVal = memory.ToArray();
memory.Close();
}
stream.Close();
} // End Using System.IO.Compression.GZipStream stream
ByteStream.Close();
} // End Using System.IO.MemoryStream ByteStream
return baRetVal;
} // End Sub Decompress

How do I get the filesize from the Microsoft.SharePoint.Client.File object?

I'm looking for a good way to get filesize from the Microsoft.SharePoint.Client.File object.
The Client object does not have a Length member.
I tried this:
foreach (SP.File file in files)
{
string path = file.Path;
path = path.Substring(this.getTeamSiteUrl().Length);
FileInformation fileInformation = SP.File.OpenBinaryDirect(this.Context, path);
using (MemoryStream memoryStream = new MemoryStream())
{
CopyStream(fileInformation.Stream, memoryStream);
file.Size = memoryStream.Length;
}
}
Which gave me a length through using the MemoryStream, but it's not good for performance. This file also does not belong to a document library. Since it's an attached file, I can't convert it to a ListItem object using ListItemAllFields. If I could convert it to a ListItem, I could get its size using: ListItem["File_x0020_Size"]
How do I get the filesize of the Client object in SharePoint using C#?

Load the File_x0020_Size field information to get it.
This is what I do when I want to list all the files in a Sharepoint 2010 folder:
//folderPath is something like /yoursite/yourlist/yourfolder
Microsoft.SharePoint.Client.Folder spFolder = _ctx.Web.GetFolderByServerRelativeUrl(folderPath);
_ctx.Load(spFolder);
_ctx.ExecuteQuery();
FileCollection fileCol = spFolder.Files;
_ctx.Load(fileCol);
_ctx.ExecuteQuery();
foreach (Microsoft.SharePoint.Client.File spFile in fileCol)
{
//In here, specify all the fields you want retrieved, including the file size one...
_ctx.Load(spFile, file => file.Author, file => file.TimeLastModified, file=>file.TimeCreated,
file => file.Name, file => file.ServerRelativeUrl, file => file.ListItemAllFields["File_x0020_Size"]);
_ctx.ExecuteQuery();
int fileSize = int.Parse((string)spFile.ListItemAllFields["File_x0020_Size"]);
}
_ctx is obviously the ClientContext you have initiated.
Here's an extended list of all Sharepoint internal fields

Can't you just use the Stream property's length?
file.Size = fileInformation.Stream.Length;

I don't know if this question was ever solved, but for the people who are looking for an answer (like I did) :
... CODE FOR GETTING THE SP.FILE ...
SP.FileInformation fileInfo = SP.File.OpenBinaryDirect(ctx, mySPFile.ServerRelativeUrl);
byte[] bodyString = ReadToEnd(fileInfo.Stream);
int length = bodyString.Length;
Console.Write(length.ToString());
... DO THE OTHER STUFF YOU NEED TO DO ....
public static byte[] ReadToEnd(System.IO.Stream stream)
{
long originalPosition = 0;
if (stream.CanSeek)
{
originalPosition = stream.Position;
stream.Position = 0;
}
try
{
byte[] readBuffer = new byte[4096];
int totalBytesRead = 0;
int bytesRead;
while ((bytesRead = stream.Read(readBuffer, totalBytesRead, readBuffer.Length - totalBytesRead)) > 0)
{
totalBytesRead += bytesRead;
if (totalBytesRead == readBuffer.Length)
{
int nextByte = stream.ReadByte();
if (nextByte != -1)
{
byte[] temp = new byte[readBuffer.Length * 2];
Buffer.BlockCopy(readBuffer, 0, temp, 0, readBuffer.Length);
Buffer.SetByte(temp, totalBytesRead, (byte)nextByte);
readBuffer = temp;
totalBytesRead++;
}
}
}
byte[] buffer = readBuffer;
if (readBuffer.Length != totalBytesRead)
{
buffer = new byte[totalBytesRead];
Buffer.BlockCopy(readBuffer, 0, buffer, 0, totalBytesRead);
}
return buffer;
}
finally
{
if (stream.CanSeek)
{
stream.Position = originalPosition;
}
}
}
Hope this will help other people, because I couldn't find a direct answer on the internet!