client.c

/**
 * Title : echo client
 * Name : Aditya Pratap Singh Rajput
 * Subject : Network Protocols And Programming using C
 * 
 * */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define MAXLINE 1024
#define PORT 5035

int main(){
  // socket descriptor creation in udp mode
  int serverDescriptor = socket(AF_INET, SOCK_DGRAM, 0);
  
  // for storing  address of address
  socklen_t addressLength;
  
  // preparing message 
  char sendMessage[MAXLINE],recvMessage[MAXLINE];
  printf("\nEnter message :");
  fgets(sendMessage,sizeof(sendMessage),stdin);
  
  // storing address in serverAddress
  struct sockaddr_in serverAddress;
  serverAddress.sin_family = AF_INET;
  serverAddress.sin_addr.s_addr = inet_addr("127.0.0.1");
  serverAddress.sin_port = htons(PORT);
  
  // storing address size 
  addressLength = sizeof(serverAddress);

  // checking connection
  connect(serverDescriptor,(struct sockaddr*)&serverAddress,addressLength);
  
  // sending and receiving the messages 
  sendto(serverDescriptor,sendMessage,MAXLINE,0,(struct sockaddr*)&serverAddress,addressLength);
  recvfrom(serverDescriptor,recvMessage,MAXLINE,0,NULL,NULL);
 
  printf("\nServer's Echo : %s\n",recvMessage);

  return 0;
}