Thread: function to receive all

Because data isn't sent all on one packet, it can be received in parts. I tried writing a function to fix this problem, but it doesn't work. Anyone know how to do this?

Code:

int GetFullRecv(CHAR *cMsg)
{
	char *tok;
	tok = strtok(cMsg, "~");
	if (tok == NULL)
	{
		if (strlen(cMsg) > 0)
			strcat(recvbuff, cMsg);
		return 0;
	}
	while (tok != NULL)
	{
		strcat(recvbuff, tok);
		ZeroMemory(tmpbuff, 350);
		strcat(tmpbuff, "RECV: ");
		strcat(tmpbuff, recvbuff);
		DispStatus(tmpbuff);
		ZeroMemory(recvbuff, 300);
		ZeroMemory(tmpbuff, 350);
		tok = strtok(NULL, "~");
	}
	if (strlen(cMsg) > 0)
		strcat(recvbuff, cMsg);
	return 0;
}

Well trampling on your message using strtok(), and assuming that your message fragment has a \0 in the right place are probably two mistakes to consider

Read my last post in this thread and adapt the code to suit. The readline function is probably the closest to what you're asking for.

ok, I've looked at that function, and tried to make it what I need. Unfortunately, my programs freeze when sending/receiving data.

I put this function in a class that has sckPeer as the open socket. I did len=sizeof(buff) (I had this in my original class recv() function and it worked.

Code:

INT PEER::ReadCRLF(CHAR *buff)
{
	char  *tmpbuf = buff;
	int   tmpsock;
	char  data;
	char  lastdata = 0;
	size_t len = sizeof(buff);

	while (len > 0)
	{
		if ((tmpsock = recv(sckPeer, &data, 1, 0)) != 1)
		{
			/*
			*  If we were interrupted, keep going,
			*  otherwise, return EOF or the error.
			*/
			if (tmpsock < 0)
				continue;
			return(tmpsock);
		}
        
		if (data == '\n')
		{
			if (lastdata == '\r')
				buff--;
			*buff = '\0';  /* don't include <CR><LF> */
			return (int)(buff - tmpbuf);
		}
		
		*buff++ = data;
		lastdata = data;
		len--;
	}
	
	return(0);
}

>>size_t len = sizeof(buff);
That'll equate to the size of the pointer, not the buffer length. Pass the lenth as a second parameter or something. This is why they were like they were in the other thread

ok, if you are passing an array of chars into the function, is there a way to determine the size of the array in the function?

Code:

char barf[256];
ZeroMemory(barf, 256);

PEER Client;
Client.ReadCRLF(barf); //the function can determine size is 256?

>>is there a way to determine the size of the array in the function?
Not really. The only method is to have a specific character as the last element of the array. Parse the array starting from the beginning until you reach said character, counting as you go. This is a bad method though, for various reasons:

- the last character could be overwritten in
error, then the parsing would go all wrong
- the special character might be placed into the "data" area of the array, which will confuse the parsing routine
- it's highly inefficient

Best (and commonly used) method, is to pass the size as a function parameter.

ok, I changed the function to take len, and it still doesn't work =/

it doesn't freeze all the way, and I'm pretty sure the server isn't getting anything

Time to start proper debugging then. Sometimes a packet trace will help you as well. http://www.etherdetect.com/

ok, am looking through code, I'm pretty sure what it's doing.

but

if (rc < 0 && errno == EINTR) continue;

why would you continue if rc is less than 0? wouldn't you want to continue if it was greater than 0?

rc would be -1 if an error had occured. If the error is EINTR, it means the recv() was interupted (maybe by the program receiving a signal for example). In this case, it's a "soft error" and the program should retry. Anything other than EINTR is fatal, and the recv() should not be reattempted.

where is EINTR defined?

Normally in something like errno.h, but it's none standard. Maybe its best that you simply remove that particular line for now.