#ifdef HAVE_CONFIG_H#include <config.h>#endif#include "client.h"int main(int argc, char *argv[]){  int cstcp,csudp,ccudp;  int server_port=8000;	//c-s tcp port  int CC_port=5000;	//c-c udp port  struct hostent *hostPtr = NULL;  struct sockaddr_in CS_link = { 0 };  struct sockaddr_in CC_link = { 0 };  char hostname[80] = "";  char buf[bufsize+1]="";  char *msg;  char *S_addr = NULL;  int recvn;  int childPid;  if (2 != argc)  {    fprintf(stderr, "Usage: %s <serverAddress> \n", argv[0]);    exit(1);  }  S_addr = argv[1];  cstcp = tcpSocket();  GetHostName(hostname, sizeof(hostname));	//get local host  CreateSockAddr(S_addr,&CS_link,server_port);	//C-S  Connect(cstcp,(struct sockaddr*) &CS_link);  msg="Client OPC 0.0.1\n";  Send(cstcp,msg);  Recv(cstcp,buf);  printf("%s",buf);  printf("Connect to server successfully,please input your nickname\n");  Fgets(buf);  Send(cstcp,buf);	//send user name  bzero(buf,bufsize);  Recv(cstcp,buf);  while(strncmp(buf,":x",2)==0)  {    printf("%s","The name has been used,please change your name:\n");    Fgets(buf);    Send(cstcp,buf);	//send user name    bzero(buf,bufsize);    Recv(cstcp,buf);  }  printf("%s",buf);  Send(cstcp,":l");	//send com to get userlist form server  printf("OnLine Users:\n");  bzero(buf,bufsize);  Recv(cstcp,buf);	//get userlist from server  printf("%s",buf);  childPid = fork();  switch (childPid)  {  case -1: // ERROR    perror("fork()");    exit(1);  case 0: // child process    while(1)    {      bzero(buf,bufsize);      if(Recv(cstcp,buf)>0)        if(strncmp(buf,":q",2)==0)          exit(0);	//get userlist from server      printf("%s",buf);    }  default :    while(1)    {      bzero(buf,bufsize);      Fgets(buf);      Send(cstcp,buf);      if(strncmp(buf,":q",2)==0)        exit(0);    }  }  return EXIT_SUCCESS;}