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

#define PORT  1111 

int main(int argc, char *argv[])
{
int sock;
struct sockaddr_in addr; 
char ret[ 4096 ];
int test;

addr.sin_family = AF_INET; 
addr.sin_addr.s_addr = inet_addr("127.0.0.1"); 
addr.sin_port = htons(PORT);
sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if(connect(sock, (struct sockaddr*)&addr, sizeof(addr))== 0 )
      {
	     printf("Receiving data ...\n");	    
	     recv(sock, ret, sizeof(ret),  0 );
	     printf("%s", ret);
      }else{
             printf("connection error code : %d\n",errno);
      }    
}

#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <memory.h>
#include <stdio.h>
#include <stdlib.h>
#include <arpa/inet.h>
#include <unistd.h>

#define SRV_PORT  1111 
#define BUF_SIZE  64 
#define TXT_QUEST "Who are you?\n"

main () {
  int s, s_new;
  int from_len;
  char buf[BUF_SIZE];
  struct sockaddr_in sin;
  struct sockaddr_in from_sin;
  
  s = socket (AF_INET, SOCK_STREAM,  0 );
  memset ((char *)&sin, '\0', sizeof(sin));
  sin.sin_family = AF_INET;
  sin.sin_addr.s_addr = INADDR_ANY;
  sin.sin_port = SRV_PORT;
  if(bind (s, (struct sockaddr *)&sin, sizeof(sin))!=- 1 ){
    printf("Binding OK\n");  
    if(listen (s,  5 )!=- 1 )    printf("listening . . . ok\n"); 
    else printf("listening failed, code %d\n",errno);
    from_len = sizeof(from_sin);
    s_new = accept (s, (struct sockaddr *)&from_sin, &from_len);
     if(s_new==- 1 ) printf("Accept error\n");
     else{ 
      printf("accept OK\n");
      write (s_new, TXT_QUEST, sizeof(TXT_QUEST));
      shutdown (s_new,  0 );
      close (s_new);
     } 
  }else{
    printf("Binding error\n");
  }
}

Binding OK
Listening . . . ok