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In Dev-C++, I'm compiling a script, and whenever I run the program that's compiled, a file called gmon.out gets outputted. Is it important? If not, how do I make the compiler not create the file while compiling?
(I'm using Dev-C++)
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I'm all for helping out, but wouldn't this be a Dev-C++ question?
"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15
"Judge not by the eye but by the heart." - Native American Proverb
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Sorry, I'll go post at sourceforge.net
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Hi!
I am currently programming server/client stuff with the c++ functions send and recv. Normally everything works fine but sometimes the client tells me it has sent a message successfully but it is not received by the server. I tracked the packets in the network and no packet had been sent. Documentation says not every successful call to send() guarantees that the data is received by the client. Unfortunately the packet is never sent (waited up to 3 minutes). Since Tcp/Ip is a reliable protocol, I expected the packets to be received by the client as long as the connection is not terminated. How can I make sure that send really sends my data? Is there a flush() command? (using Tcp/Ip non blocking windows socket, checking for send/receive with select).
Any help would be greatly appreciated!!!
Thx
Flo
P.S. Before you ask: it has to be c++ send and recv - no MFC or C# stuff...
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I would check every send and recv call (breakpoint) and add up the bytes sent/received.
Keep in mind that recv doesn't always give you all the bytes you request in one call and
send doesn't always send the number of bytes you asked it to in one call. Check those return
values!
Mark
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I checked the number of bytes received and sent. The problem is that the send command really does not send anything (I observed my network traffic) but tells me it has sent the correct amount of bytes. I doublechecked with breakpoints and everything I can think of and I have no idea why it does not send anything. The other side is listening with select and no data is to be received. This happens only sometimes. Normally it works fine.
Frustrating 
Flo
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florianhaar wrote: Frustrating
Indeed!
Which select are you using? Can you post the code you use to receive (it's almost always a
problem on the receiving end)?
Mark
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Thanks for your help so far Mark. I hope this code snippet gives you an idea for a solution:
TIMEVAL tv;
tv.tv_sec=0;
tv.tv_usec=5;
FD_ZERO(&clientSet);
FD_SET(theClient->sock,&clientSet);
if ((errCode=select(0,&clientSet,NULL,NULL,&tv))>0)
{
if ((recvMsgSize=recv(theClient->sock,addBuffer,maxRead,0))<=0)
{
//error handling
...
}
else
message handling...
I do not receive an error or a message. Select() returns only timeout.
Flo
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if ((recvMsgSize=recv(theClient->sock,addBuffer,maxRead,0))<=0)
...
What is maxRead?
How are you handling if recvMsgSize < maxRead after the call?
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maxRead is the maximum number of bytes the buffer can store. if recvMsgSize is smaller than maxRead (which is normally the case) I copy the data to additional buffers and combine them as soon as all bytes are received. With my problem the data received is always smaller than maxRead.
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hmmm From what I've seen there shouldn't be a problem.
You've debugged the code? Examining network packets isn't necessarily the way to debug since the
potocol is free to re-packetize your data as needed.
Have you changed any socket options on either end?
There's a bug in the code somewhere 
Mark
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I guess I have to think through my code step by step once again. At least I know now, that send() should send after 200ms as long as the connection is established.
Thanks again for your help!
Flo
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If you'd like to post the send-side code I'd be happy to look at it as well.
Mark
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I generally agree with Mark's observation that problems like this are almost always caused by code on the receiving side.
Here, you have set the timeout for select() to 5 microseconds. That's way too short.
Your understanding of the send() function is slightly wrong. send() does not actually send bytes out over the wire; that happens later when the winsock TCP stack determines that it's time to send data on the wire, after considertion of things like Nagle, delayed ACK etc. Rather, a successful call to send() only indicates that the winsock stack has successfully transferred data in your user buffer to its internal winsock buffer. The return value from send() tells you exactly how much of your buffer has been accepted; you should therefore inspect the returned value to ensure that winsock transferred everything to its internal buffer.
So, if you are debugging and single-stepping through your code, and you see a successful completion of the call to send(), then it's probably still too early for a sniffer to see the actual data on the wire. That will happen, but it will happen at some indeterminate time in the future.
Mike
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Thanks Mike!
Maybe you meant to post this to the OP
For some reason I assumed his code was in a loop. If it's not then that 5microsecond timeout is definitely not going to work (well, rarely).
Mark
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Hi Flo,
Check out Mike O'Neill's reply above.
I asked previously how you're handling it when you don't receive the number of bytes requested.
Are you looping until you get the bytes you're expecting or just trying to recv once after the
5microsecond wait?
Mark
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If I remember it correctly, If the packet size become too small, very small that it doesnt send it until the successive packets join together to make good "chunk". It's somewhat termed as "Neigile's" Nagle algorithm or so. just check the size of the packets your are sending.
-- modified at 13:16 Friday 26th January, 2007
Code-Frog:So if this is Pumpkinhead. Time for him to run and hide. It's an interesting thought really.
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Nagle
The data is sent after (by default on Windows Sockets) 200ms though.
Mark
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Done. Thanks 
Code-Frog:So if this is Pumpkinhead. Time for him to run and hide. It's an interesting thought really.
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Hi all. Im having trouble making this file read-out look nice.
The code is this:
<br />
#include <fstream><br />
using namespace std;<br />
<br />
int main(){<br />
char buffer[100];<br />
ifstream file("file.dat",ios::end);<br />
if(file.fail()){<br />
printf("File not found.\n");<br />
}<br />
printf("File contents read the following:\n");<br />
while(file >> buffer){<br />
printf("\n%s ",buffer);<br />
}<br />
file.close();<br />
system("pause");<br />
return 0;<br />
}<br />
The file "file.dat" reads "This is only a test" inside. But when i run the program it reads:
File contents read the following:
This
is
only
a
test
-----------------------
So i figured maybe it was a problem with my way of printing the message in the console. So i switched the printf around from this
<br />
printf("\n%s ",buffer);<br />
To this
<br />
printf("%s\n ",buffer);<br />
To this
<br />
printf("%s",buffer);
And still cant come up with a better looking format. Is there another way i can make it print the way its saved in the file? Thanx in advance!
P.S.
If i made the print like this: printf("%s ",buffer); It would print the first line in the file as its written in the file. But if there were two lines or three etc. It prints it like this
"This is only a test This is only a test This is only a test"
Which isnt what im looking to do. I'd like it look something like
This is only a test
This is only a test
This is only a test
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I think you may find this link very useful
www.dorota.ecs.fullerton.edu/classes/CS231/lect3-cs.ppt
or Google on "ios:end"
John P.
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jparken wrote: www.dorota.ecs.fullerton.edu/classes/CS231/lect3-cs.ppt
Is http://www.dorota.ecs.fullerton.edu/ a valid domain?
"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15
"Judge not by the eye but by the heart." - Native American Proverb
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dellthinker wrote: Is there another way i can make it print the way its saved in the file?
Yes. Either read and print it on a line-by-line basis, or read each word into an array and print the contents of the array as you see fit.
"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15
"Judge not by the eye but by the heart." - Native American Proverb
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Operator >> used with (i/o)fstream read one word from actual position in file to first space or end line. If you want read line you must use getline.
You can read about it there: http://www.cplusplus.com/istream::getline
-----------------------------------------------------------------
Surely without war there would be no loss
Hence no mourning, no grief, no pain, no misery
No sleepless nights missing the dead... Oh, no more
No more war
[Sleepless - Cradle of Filth]
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I am looking for the Windows API that opens the Select User dialog.
Can anyone give a reference or an example on how to do this ?
Thanks,
Ami
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