Miscellany

#include <sys/types.h>#include <sys/socket.h>#include <arpa/inet.h>#include <string.h>#include <stdlib.h>#include "errlib.h"#include "sockwrap.h"#define MAXBUFL 255 #define ADD_PORT 9999char *prog;static void add_client (int sockfd){  ssize_t n;  char buf[MAXBUFL+1];  while ( (n = Readline(0,buf,sizeof(buf))) > 0)  {    Writen (sockfd, buf, n);    if ( (n = Readline(sockfd,buf,sizeof(buf))) > 0)      Writen (1, buf, n);    else      err_quit("(%s) error - unexpected EOF from server", prog);  }}int main (int argc, char *argv[]){  int sockfd;  struct sockaddr_in servaddr;  // for libraries to know the program name  prog = argv[0];  // check the arguments  if (argc != 2)    err_quit ("usage: %s IPaddress_of_server", prog);  // create socket  sockfd = Socket(AF_INET, SOCK_STREAM, 0);  // specify address of server to connect to  memset (&servaddr, 0, sizeof(servaddr));  servaddr.sin_family = AF_INET;  servaddr.sin_port   = htons(ADD_PORT);  Inet_pton (AF_INET, argv[1], &servaddr.sin_addr);  // try to connect  Connect(sockfd, (SA*) &servaddr, sizeof(servaddr));  // read the questions, send to server, get and display the answers  add_client (sockfd);  // done  exit(0);}