Results 1 to 19 of 19

Thread: Receive file over TCP

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Join Date
    May 2008
    Posts
    21
    Qt products
    Qt/Embedded
    Platforms
    Unix/X11

    Default Receive file over TCP

    Can anyone give me a sample program how to receive a binary files over TCP using QSocket or other similar class?

    Thx in advance..

  2. #2
    Join Date
    May 2008
    Location
    Kyiv, Ukraine
    Posts
    418
    Qt products
    Qt4
    Platforms
    Unix/X11
    Thanks
    1
    Thanked 29 Times in 27 Posts

    Default Re: Receive file over TCP

    Quote Originally Posted by winarko View Post
    Can anyone give me a sample program how to receive a binary files over TCP using QSocket or other similar class?

    Thx in advance..
    http://doc.trolltech.com/4.4/examples.html#network

  3. #3
    Join Date
    May 2008
    Posts
    21
    Qt products
    Qt/Embedded
    Platforms
    Unix/X11

    Default Re: Receive file over TCP

    Thanks but I still have a problem. I'll let u know my project is:
    1.Build a Simple HTTP Server on embedded device so that a browser can connect and receive a HTML page.(done)
    2.Let the browser (client PC) upload a GIF file to that server. I use FrontPage2003 to develop a HTML script and FileUpload Component from FrontPage2003. (not done yet)
    The problem is my embedded device can't receive the whole packets transfered, it only can receive some part of the file.
    Do u have any solution??

    Thx in advance.

  4. #4
    Join Date
    May 2008
    Posts
    15
    Qt products
    Qt3 Qt4
    Platforms
    Unix/X11 Windows
    Thanks
    3

    Default Re: Receive file over TCP

    The problem is my embedded device can't receive the whole packets transfered, it only can receive some part of the file.
    Why? buffer to small in the embedded device? Where happens the fragmentation?

  5. #5
    Join Date
    May 2008
    Posts
    21
    Qt products
    Qt/Embedded
    Platforms
    Unix/X11

    Default Re: Receive file over TCP

    This is my read socket procedure:

    Qt Code:
    1. while (socket->bytesAvailable())
    2. {
    3. myfile.writeBlock(socket->readAll());
    4. myfile.flush();
    5. socket->waitForMore(1);
    6. }
    To copy to clipboard, switch view to plain text mode 

    When I simulated this program on PC (using localhost address 127.0.0.1), I can get the whole part of the file I sent. But unfortunately I can't do that for my embedded device.

    Any suggestion??

    Thx for reply
    Last edited by jpn; 29th May 2008 at 13:11. Reason: missing [code] tags

  6. #6
    Join Date
    May 2008
    Posts
    15
    Qt products
    Qt3 Qt4
    Platforms
    Unix/X11 Windows
    Thanks
    3

    Default Re: Receive file over TCP

    maybe I'm missing something...You have to interpret the length-key of the httpheader somewhere.

  7. #7
    Join Date
    May 2008
    Posts
    21
    Qt products
    Qt/Embedded
    Platforms
    Unix/X11

    Default Re: Receive file over TCP

    Maybe I should try to find another way...

  8. #8
    Join Date
    May 2008
    Posts
    15
    Qt products
    Qt3 Qt4
    Platforms
    Unix/X11 Windows
    Thanks
    3

    Default Re: Receive file over TCP

    Maybe I should try to find another way...
    Do you understand the problem?

    Example:
    the file size is 100.000 Bytes
    the 1st tcp/ip paket has 50.000 Bytes, when it arrives it triggers your slot, you read it, and think that was all
    in the meantime the 2nd paket arrives, but you don't expect it, you think that all the data has been send in the first paket which triggert the slot.

    Understandable?

  9. #9
    Join Date
    May 2008
    Posts
    21
    Qt products
    Qt/Embedded
    Platforms
    Unix/X11

    Default Re: Receive file over TCP

    Quote Originally Posted by MaximA View Post


    in the meantime the 2nd paket arrives, but you don't expect it, you think that all the data has been send in the first paket which triggert the slot.
    Look at my program:
    Qt Code:
    1. while (socket->bytesAvailable()) // In this loop, I wait for new incoming packet until no packet arrived anymore
    2. {
    3. myfile.writeBlock(socket->readAll());
    4. myfile.flush();
    5. socket->waitForMore(1);
    6. }
    To copy to clipboard, switch view to plain text mode 
    Last edited by jpn; 29th May 2008 at 13:11. Reason: missing [code] tags

  10. #10
    Join Date
    Oct 2006
    Posts
    279
    Qt products
    Qt4
    Platforms
    MacOS X Unix/X11 Windows
    Thanks
    6
    Thanked 40 Times in 39 Posts

    Default Re: Receive file over TCP

    from the Qt Docs:
    qint64 QAbstractSocket::bytesAvailable () const [virtual]
    Returns the number of incoming bytes that are waiting to be read.
    That does not mean that there aren't more coming.

  11. #11
    Join Date
    May 2008
    Posts
    21
    Qt products
    Qt/Embedded
    Platforms
    Unix/X11

    Default Re: Receive file over TCP

    That does not mean that there aren't more coming.
    Do you know while loop??? If the value in the bracket "WHILE(value)" is zero, the loop ends, and when the value greater than zero (that means there are still a data in socket), the loop still work.

    OK,can u give me a sample code to receive continuous data from socket?

Similar Threads

  1. QtHelp Module - registering compressed help file gives error
    By Ankitha Varsha in forum Qt Programming
    Replies: 1
    Last Post: 16th May 2008, 15:14
  2. Set up the Qt4.3.2 with Visual Studio 2005
    By lamoda in forum Installation and Deployment
    Replies: 6
    Last Post: 30th January 2008, 07:51
  3. file renaming on windows
    By jdd81 in forum Qt Programming
    Replies: 9
    Last Post: 2nd October 2007, 20:41
  4. qt-3.3.8 fail in scratchbox
    By nass in forum Installation and Deployment
    Replies: 0
    Last Post: 25th May 2007, 16:21
  5. Sending Binary File with QFTP
    By nbkhwjm in forum Newbie
    Replies: 2
    Last Post: 7th March 2007, 19:10

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Qt is a trademark of The Qt Company.