recv unable to receive first to characters. REALLY head ditching!!!!!!

naveenisback · 08-13-2009, 08:40 AM

Hi,

OS:red flag
language: "C"
I wrote a socket server program, in which receive function is like this..

Code:

char* receive(int connected, char recv_data[])
{

        unsigned int len, bytes_received;

        bytes_received = recv(connected,(char *)&len,6,0);//receive msglength

        memset(recv_data, 0, sizeof(recv_data));

        unsigned int h_len = ntohl(len);

        printf("received lenth is %d\n", h_len);

        char *recvbufptr = recv_data;

        while(1)
        {
                recv:bytes_received = recv(connected, (char*)recvbufptr, h_len ,0);//receive msg
                printf("BYTES RECEIVED IS %d\n H_LEN IS %d\n   bufptyr%s\n", bytes_received, h_len, recvbufptr);

                if(bytes_received == h_len)
                {
                        printf("INSIDE IF\n");
                        break;
                }
                else
                {
                        if((bytes_received == 0) ||(bytes_received == -1))
                        {
                                perror("Recv Fails:");
                                exit(1);

                        }
                        goto recv;
                        printf("INSIDE ELSE \n");
                        h_len = h_len-bytes_received;
                                                                       recvbufptr = recvbufptr+bytes_received;
                }
        }//while

        printf("bytes received is %d\n", bytes_received);


        recv_data[bytes_received] = '\0';

#ifdef DEBUG
        printf("\n RECIEVED BUFFER LENGTH = %d\n" ,bytes_received);
#endif
        printf("\n RECIEVED DATA = %s\n " , recv_data);

return recv_data;
}

I have to communicte with windows in which client is running. the problem is - sometime the first two characters of xml message is are not receiving. pls suggest except using "MSG_WAITALL" flag.

I raised this question many tiomes, but i dint get good answer.. this is the problem from 3 months. I hope this time I will get the ans.

Thankx in Advance

TB0ne · 08-13-2009, 11:46 AM

Quote:

Originally Posted by naveenisback

Hi,

OS:red flag
language: "C"
I wrote a socket server program, in which receive function is like this..

I have to communicte with windows in which client is running. the problem is - sometime the first two characters of xml message is are not receiving. pls suggest except using "MSG_WAITALL" flag.

I raised this question many tiomes, but i dint get good answer.. this is the problem from 3 months. I hope this time I will get the ans.

Thankx in Advance

Well, you got answers in your other threads about this same issue, but never said if they worked or not. And you have one solution, which you mention, but say you don't want it.

Don't know what else to suggest....except for you to spell out your words, and write/spell clearly.

dwhitney67 · 08-16-2009, 12:41 PM

For starters, fix this statement:

Code:

bytes_received = recv(connected,(char *)&len,6,0);//receive msglength

to be:

Code:

bytes_received = recv(connected,(char *)&len,sizeof(len),0);//receive msglength

Your original code is indicating that you want to receive 6 bytes, and store them into a 4-byte entity. Silly mistakes like this are the reason that hard-coded constants are shunned in programming.

naveenisback · 08-17-2009, 07:51 AM

Thanks a lot Mr.dwhitney67.

It is working well.