your code is only reading one line (as in stops at a \n), but my data that's being sent, can include more than 0 \n's, could that be causing the problem?
You could use something else to mean end-of-message, how about a carriage return, '\r'?
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maybe somewhere (not at the end) in the data i send, there is a \0...?
I don't think so. You could compare how many bytes you read() against how many bytes str_len sees, if they disagree a lot there's a NULL or newline in the middle.
Wait! That's it! Your str_len function stops at a newline and some of your messages have a newline in the middle!
You still need to divide it into records somehow though. The code can't be relied on if you don't.
i dont understand, the only times i use that str_len is when the strings have no \n inside...
That's on the server end. receive_message has no way to tell the client how long it is, so the client receives something and uses str_len, which stops at newlines.
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when the problem happens, it stops reading at the first newline that it finds, how do you make it read past it until it finds a \0 ?
It's because your str_len function stops at newlines. Just use ordinary strlen(), which doesn't.
And you have to separate your records somehow. You simply cannot depend on receiving things in the same size chunks you sent them. It can work the other way too -- you could do two small sends, and do one big receive.
i just changed all of them to strlen, and the problem still occurs
You can't just blindly make the changes without making the other fixes I said too. Your code makes a lot of wrong assumptions about the behavior of sockets. It doesn't operate as expected because sockets don't either.
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how is read supposed to work, does it normally skip the \n characters?
Now you ask, after I've been trying to point it out for weeks...
read() works completely raw. It alters none of the data that passes through it. It doesn't do anything special to nulls or newlines, and nothing in the data makes it stop early. It might stop early for other reasons though, so you have to check its return value, to see if you read as many bytes as you thought you did. write() is the same. completely raw. But you have to check its return value in case it wrote less than you asked it to.
It's not an error for it to not send it all. If it returns 0 or -1, it's an error.
---------- Post updated at 03:57 PM ---------- Previous update was at 03:55 PM ----------
It's not an error to not receive it all, either. You have to keep reading until you know you're done. You don't know how long the message will actually be unless your server tells you somehow, which is why I suggested using \n or \n to mark the end of a record and showed receiving code that looked for that.
hai guys,
I'm doing a project in which one server communicates with several clients. How can i do it when i have different port numbers???:confused: (0 Replies)
Hi,i now moved into a different section where i need to use sockets.
i am completely nill in sockets.
can some body please provide me what are the requirements for a socket.
to use sockets in c.
thanks (1 Reply)
anyone and teach me how to save standard output to a file in a client/server socket. I know how to read them to the screen but i'm not quite sure how to save them to a file.
my read to screen file code:
memset(line, 0x0, LINE_ARRAY_SIZE);
while (recv(connectSocket, line, MAX_MSG, 0) >... (1 Reply)
Is it possible to trace the packages and the statuses of client's and/or server's sockets by the UNIX network administrative tools?
Two applications interact via sockets. There is no problem if they stay in the same network segment. If their hosts connected through the firewall then they aren't... (4 Replies)
Is there a way to see what sockets are in use? The developers here are getting some defunct processes and they would like to get a socket list.
This is on a Solaris 8 machine.
Thanks! (1 Reply)
Hai,
How cani declare socket and collect the data in a string varialbe.
Since i am new to this i am asking this.
Can we connect multiple port.
Thank you. (6 Replies)
I am looking for a way to have a program listen on a port (example: 8000) for communication I will be sending via that port to it(Linux Kernel machine). Once it recieves an appropiate command I need it to run a .bat file in linux.
I know what I need to do but I am running into a few problems:... (8 Replies)
Hi !
I had a verry simple question to ask...
In unix when we create pipes.. the unnamed pipes that is...
is there any way to access those pipes outside the code ?
Another thing.. do sockets have an entry in the inode table ?
TIA,
Devyani. (1 Reply)