How to read a file into a stream

[ad]

Hi,
I have a file (c:\myFile.zip) in the Server.
How can I read the file into a Stream?

[Marc Gravell]

Well, File.OpenRead(@ "c:\myfile.zip" ) would give you a FileStream
looking at the file.

With the exception of MemoryStream, you don't really really read *into*
a stream; rather, the stream is a pipe through which you read the file
as you need it (i.e. a few thousand bytes at a time). Memory stream, on
the other hand, is a bucket.

Marc

[Jon Skeet [C# MVP]]

ad <fl****@wfes.tc c.edu.twwrote:

I have a file (c:\myFile.zip) in the Server.
How can I read the file into a Stream?

Open it as a FileStream and that *is* a stream. Please give me details
on what you're really trying to do.

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too

[Marc Gravell]

Trying to predict your next question, can I offer the following example
(which also servers a general demonstration of stream usage)? This code
opens the file (at inPath), obtains the first file in the zip archive,
and writes it (to outPath).

Note that this uses #ZipLib to handle zip files (not handled natively
by the CLR); note that at any point in time we are only handling 2048
bytes of data, even for a 500Mb file - so we haven't read the entire
file into memory first.

We have three streams here; we have connected two "pipes" (streams)
together, with the nifty #ZipLib code in the middle, so when you
request e.g. 2048 bytes, it reads {some} bytes from the FileStream,
decompresses it, and gives you back {some} bytes (bytesRead). We then
write this amount from the buffer to out output stream.

Code maynot be 100% - I have ported it (in notepad) from a more complex
example.

int BUFFER_LENGTH = 2048;
byte[] buffer = new byte[BUFFER_LENGTH];
using(inFile = System.IO.File. OpenRead(inPath ))
using(zip = new
ICSharpCode.Sha rpZipLib.Zip.Zi pInputStream(in File))
using (System.IO.File Stream outFile =
System.IO.File. Create(outPath) ) {
zip.GetNextEntr y();
int bytesRead;
while((bytesRea d = zip.Read(buffer , 0, BUFFER_LENGTH)) 0)
{
outFile.Write(b uffer, 0, bytesRead);
}
outFile.Flush() ;
outFile.Close() ;
}

Marc

[Arne Vajhøj]

Marc Gravell wrote:

Note that this uses #ZipLib to handle zip files (not handled natively
by the CLR);

I use #ZipLib as well.

But as someone once pointed out to me then .NET supports
java.lang.zip in the vjslib assembly for J# !

Arne