recv() second arg

Ducky · 07-04-2009, 09:49 AM

I dont know if it makes any sense but its kinda strange what i found.

From the client i send send(server, size, 8, 0); with the second arg: char* size.

On the server i recv(client, size, 8, 0); with the second arg: char size[8].

If i change the type to char* size on the server too, it stops working.

Its not that important but maybe someone had an idea why is that.

**Salem** · 07-04-2009, 11:23 AM

> If i change the type to char* size on the server too, it stops working.
You become responsible for making sure it points to allocated memory.

Ducky · 07-04-2009, 12:57 PM

Thank you Salem!

So i guess it means i shouldnt use it if its not allocated.

By allocated i guess you mean, dynamically like that:

Code:

char* size = new char[8];

Unfortunately i have to use char* size because with char size[8] it wont compile on that line on the client side.

Code:

                     strcpy(Cmd, "Upload");
                     send(server, Cmd, 7, 0);
                     Sleep(5);
                     send(server, RemoteP, MAX_PATH, 0);
                     ifstream r(LocalP, ios::in | ios::binary);
                     // get size of file:
                     r.seekg (0, ios::end);
                     sz = r.tellg();
                     r.seekg (0, ios::beg);
                     // error: need char* for size
                     size = itoa(sz, buff, 10);
                     send(server, size, 8, 0);

                     char* Buffer = new char [sz];
                     ZeroMemory(Buffer, sz);
                     r.read(Buffer, sz);
                     send(server, Buffer, sz, 0);
                     cout << Buffer << endl;

                     r.close();
                     delete[] Buffer;

**Salem** · 07-04-2009, 02:17 PM

Try reading the manual page for itoa then.

Quote:

Originally Posted by a man page

RETURN VALUES

The function itoa() always returns the value string. There is no error return.

Forget about size, just use buff

Ducky · 07-04-2009, 02:48 PM

Thanks a lot, its working!

07-04-2009, 09:49 AM	#1
Ducky Registered User Join Date: Dec 2007 Location: France Posts: 395	recv() second arg I dont know if it makes any sense but its kinda strange what i found. From the client i send send(server, size, 8, 0); with the second arg: char* size. On the server i recv(client, size, 8, 0); with the second arg: char size[8]. If i change the type to char* size on the server too, it stops working. Its not that important but maybe someone had an idea why is that. __________________ Using Code::Blocks,MingW with Windows.
Ducky is online now

07-04-2009, 11:23 AM	#2
Salem and the hat of vanishing Join Date: Aug 2001 Location: The edge of the known universe Posts: 21,214	> If i change the type to char* size on the server too, it stops working. You become responsible for making sure it points to allocated memory. __________________ If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut. Up to 8Mb PlusNet broadband from only £5.99 a month!
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07-04-2009, 12:57 PM	#3
Ducky Registered User Join Date: Dec 2007 Location: France Posts: 395	Thank you Salem! So i guess it means i shouldnt use it if its not allocated. By allocated i guess you mean, dynamically like that: Code: char* size = new char[8]; Unfortunately i have to use char* size because with char size[8] it wont compile on that line on the client side. Code: strcpy(Cmd, "Upload"); send(server, Cmd, 7, 0); Sleep(5); send(server, RemoteP, MAX_PATH, 0); ifstream r(LocalP, ios::in \| ios::binary); // get size of file: r.seekg (0, ios::end); sz = r.tellg(); r.seekg (0, ios::beg); // error: need char* for size size = itoa(sz, buff, 10); send(server, size, 8, 0); char* Buffer = new char [sz]; ZeroMemory(Buffer, sz); r.read(Buffer, sz); send(server, Buffer, sz, 0); cout << Buffer << endl; r.close(); delete[] Buffer; __________________ Using Code::Blocks,MingW with Windows. Last edited by Ducky; 07-04-2009 at 01:10 PM.
Ducky is online now

07-04-2009, 02:48 PM	#5
Ducky Registered User Join Date: Dec 2007 Location: France Posts: 395	Thanks a lot, its working! __________________ Using Code::Blocks,MingW with Windows.
Ducky is online now

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