Socket communication programming for Linux system UDP

Sender:

/*
* FILE:MAIN.C
* Author:tianshuai
*
* Created on November 29, 2011, 10:34
*
* Main implementation: Send 20 text messages, and then send a termination message
*/

#include <stdio.h>
#include <stdlib.h>

#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>

int port=6789;
int main (int argc, char** argv) {
int socket_descriptor; Set interface Description Word
int iter=0;
Char buf[80];
struct sockaddr_in address;//address for handling network traffic

Bzero (&address,sizeof (address));
Address.sin_family=af_inet;
ADDRESS.SIN_ADDR.S_ADDR=INET_ADDR ("127.0.0.1");//It's not the same here.
Address.sin_port=htons (port);

Create a UDP socket

Socket_descriptor=socket (af_inet,sock_dgram,0);//ipv4 sock_dgram datagram Sockets (UDP protocol)

for (iter=0;iter<=20;iter++)
{
/*
* SPRINTF (S, "%8d%8d", 123, 4567); Generated: "123 4567"
* After formatting to a string into the S
*/
sprintf (BUF, "Data packet with ID%d\n", ITER);

/*int PASCAL far sendto (SOCKET s, const char far* buf, int len, int. flags,const struct sockaddr far* to, int tolen);
* S: A descriptive word for the socket interface.
* BUF: The buffer containing the data to be sent.
* Len:buf The length of the data in the buffer.
* Flags: Call way flag bit.
* To: (optional) pointer to the address of the destination socket interface.
* The length of the address referred to by tolen:to.
*/
SendTo (Socket_descriptor,buf,sizeof (BUF), 0, (struct sockaddr *) &address,sizeof (address));
}

sprintf (buf, "stop\n");
SendTo (Socket_descriptor,buf,sizeof (BUF), 0, (struct sockaddr *) &address,sizeof (address));//Send Stop command
Close (Socket_descriptor);
printf ("Messages sent,terminating\n");

Exit (0);

return (exit_success);
}

Receiving Party:

/*
* FILE:MAIN.C
* Author:tianshuai
*
* Created on November 29, 2011, 10:34
*/

#include <stdio.h>
#include <stdlib.h>

#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>

int port=6789;

int main (int argc, char** argv) {

int Sin_len;
Char message[256];

int socket_descriptor;
struct sockaddr_in sin;
printf ("Waiting for data form sender \ n");

Bzero (&sin,sizeof (sin));
Sin.sin_family=af_inet;
Sin.sin_addr.s_addr=htonl (Inaddr_any);
Sin.sin_port=htons (port);
Sin_len=sizeof (SIN);

Socket_descriptor=socket (af_inet,sock_dgram,0);
Bind (Socket_descriptor, (struct sockaddr *) &sin,sizeof (sin));

while (1)
{
Recvfrom (socket_descriptor,message,sizeof (message), 0, (struct sockaddr *) &sin,&sin_len);
printf ("Response from server:%s\n", message);
if (strncmp (message, "Stop", 4) = = 0)//The message received is "stop"
{

printf ("Sender has told me to end the connection\n");
Break
}
}

Close (Socket_descriptor);
Exit (0);

return (exit_success);
}

Socket communication programming for Linux system UDP