sock.send question

tqa · 11-26-2008, 01:40 AM

my code looks as below:

Code:

cout<<"Sending List of Node..\n";
    //code to send List1 and List2
    sckt::byte data[256];
	 for(int g=c; g>=0; g--)
	     {
              arraylist2[g]=d.Data(path2[g]);
	      //sckt::byte data[256];
	      strcpy( reinterpret_cast <char*> (data), arraylist2[g].c_str());
	      sock.Send (data, sizeof (data));
             }

the code can run well, but the output is not as I thought it would be.
only value of g=c are send.

is it the sock.send only run once?
that means even we do the for loops, the sock.send only run once then it will terminate?

hope my question is clear.

Thank you

dmail · 11-26-2008, 06:17 PM

I recognise the namespace is this http://code.google.com/p/sckt/ ?
What type of socket is it UDP or TCP? what is the value of C? is it 0?
Why are you copying the data and not just sending it like so

Code:

 sock.Send (arraylist2[g].c_str(), arraylist2[g].size() );

If it is a problem with the library you can contact the author via the google project page or on <a href="http://www.gamedev.net/community/forums/profile.asp?mode=display&id=99059">gamedev.net</a>

tqa · 11-26-2008, 09:03 PM

I am using the TCP socket. I think it is not the problem with the library since I only use the sckt function from the site that u mention ( but the file that I found is sckt-0.4), and I have add a few code to suit my program.

Actually I thought that we have to use the variable to send a data, so my intention is to replace the var data with my value.

The c value is an integer which > 0.

Anyway, I have try the code that you have suggested, but i get this error

error: invalid conversion from ‘const char*’ to ‘const sckt::byte*’
error: initializing argument 1 of ‘sckt::uint sckt::TCPSocket::Send(const sckt::byte*, sckt::uint)’

tqa · 11-26-2008, 11:58 PM

Anyway, this is my code for client side.
I am not using the for loops for at the client side because I thought all the value will be stored in buf..

Code:

 sckt::byte buf[1024];

    sock.Recv(buf, sizeof(buf));
    cout << buf <<endl;

Is it my code incorrect?

dwhitney67 · 11-27-2008, 05:09 AM

Quote:

Originally Posted by tqa

I am using the TCP socket. I think it is not the problem with the library since I only use the sckt function from the site that u mention ( but the file that I found is sckt-0.4), and I have add a few code to suit my program.

Actually I thought that we have to use the variable to send a data, so my intention is to replace the var data with my value.

The c value is an integer which > 0.

Anyway, I have try the code that you have suggested, but i get this error

error: invalid conversion from ‘const char*’ to ‘const sckt::byte*’
error: initializing argument 1 of ‘sckt::uint sckt::TCPSocket::Send(const sckt::byte*, sckt::uint)’

Change your call to Send() as follows:

PHP Code:



sock.Send ((const sckt::byte*)arraylist2[g].c_str(), arraylist2[g].size() );

P.S. You should read the sckt.hpp file so that you further understand how the sckt::byte and sckt::uint are defined. I'm not quite sure I understand why the author of the sckt library thought this was important to define (as opposed to using standard system types), but nevertheless he did.

dwhitney67 · 11-27-2008, 05:39 AM

Quote:

Originally Posted by tqa

Anyway, this is my code for client side.
I am not using the for loops for at the client side because I thought all the value will be stored in buf..

Code:

 sckt::byte buf[1024];

    sock.Recv(buf, sizeof(buf));
    cout << buf <<endl;

Is it my code incorrect?

This code is correct, however it *may* only work for short messages. When using TCP sockets, the delivery of the message is guaranteed... however not necessary in one packet!

Thus you will need to insert your Recv() method in a loop to continue receiving data until a condition has been met (i.e. a complete message has been received). Pay careful attention to the return value of Recv() so that you can use it to adjust the insert position within your buf array.

I have not compiled the following, so think of it as "pseudocode":

PHP Code:



sckt::byte buf[1024];

// assume messages are newline terminated
sckt::uint bytesReceived = 0;

while (!strchr(buf, '\n') && (bytesReceived < sizeof(buf))
{
  bytesReceived = sock.Recv(buf + bytesReceived, sizeof(buf) - bytesReceived);
}

P.S. If you are developing for Linux-only, feel free to consider using the TCP/UDP Socket library I developed (it is very similar to the sckt library you are currently using). It is located here.

dmail · 11-27-2008, 06:24 AM

"that means even we do the for loops, the sock.send only run once then it will terminate?"
Is the socket set to non blocking and when you say the above does the application end due to an exception or are you just referring to the loop exiting? Try wrapping the code in a try/catch block.

tqa · 11-27-2008, 07:14 PM

Thanks for the great ideas
I have tried the send code. It work well..but still cant receive all the data that i want to send.

then, i try below code, as suggested by you.

Code:

sckt::byte buf[1024];

// assume messages are newline terminated
sckt::uint bytesReceived = 0;

while (!strchr(buf, '\n') && (bytesReceived < sizeof(buf))
{
  bytesReceived = sock.Recv(buf + bytesReceived, sizeof(buf) - bytesReceived);
}

error: call of overloaded ‘strchr(sckt::byte [1024], char)’ is ambiguous
/usr/include/string.h:168: note: candidates are: char* strchr(const char*, int) <near match>
/usr/lib/gcc/i386-redhat-linux/4.1.2/../../../../include/c++/4.1.2/cstring:107: note: char* std::strchr(char*, int) <near match>

Actually my program have been run well using this code on client side

Code:

int a = 4;
    cout<<"List1:"<<endl;
    for (int b=a; b>0; b--)
    { 
      sock.Recv(buf, sizeof(buf));
         cout << buf <<endl;       
    }*/

though i think it is not a good code because im defining the value for looping.
And I think that your suggested code is very efficient and I want to use that code.BUt, it have errors.hope that you can help me.

anywaY, I already get the page that you suggested, but can't open it,
The requested URL /SocketLibrary-1.05.tgz was not found on this server.
Thank you

dwhitney67 · 11-27-2008, 08:34 PM

Quote:

Originally Posted by tqa

Thanks for the great ideas
I have tried the send code. It work well..but still cant receive all the data that i want to send.

then, i try below code, as suggested by you.

Code:

sckt::byte buf[1024];

// assume messages are newline terminated
sckt::uint bytesReceived = 0;

while (!strchr(buf, '\n') && (bytesReceived < sizeof(buf))
{
  bytesReceived = sock.Recv(buf + bytesReceived, sizeof(buf) - bytesReceived);
}

error: call of overloaded ‘strchr(sckt::byte [1024], char)’ is ambiguous
/usr/include/string.h:168: note: candidates are: char* strchr(const char*, int) <near match>
/usr/lib/gcc/i386-redhat-linux/4.1.2/../../../../include/c++/4.1.2/cstring:107: note: char* std::strchr(char*, int) <near match>

It would seem that you need to cast the buf to a const char* in the strchr() function.

Quote:

Originally Posted by tqa

anywaY, I already get the page that you suggested, but can't open it,
The requested URL /SocketLibrary-1.05.tgz was not found on this server.
Thank you

Sorry for the URL issue; it has been corrected.