求助 关于客户端／服务端小程序

[yzq8951]

这个是我看书上的代码

服务端
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/wait.h>

#define MYPORT 5000
#define BACKLOG 10

int main(void)
{
int sockfd,new_fd;
struct sockaddr_in my_addr;
struct sockaddr_in their_addr;
int sin_size;
if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1){
perror("socket");
exit(1);
}

my_addr.sin_family=AF_INET;
my_addr.sin_port=htons(MYPORT);
my_addr.sin_addr.s_addr=INADDR_ANY;
bzero(&(my_addr.sin_zero),8);
if(bind(sockfd,(struct sockaddr *)&my_addr,sizeof(struct sockaddr))==-1){
perror("bind");
exit(1);
}

if(listen(sockfd,BACKLOG)==-1) {
perror("listen");
exit(1);
}

while(1){
sin_size=sizeof(struct sockaddr_in);
if((new_fd=accept(sockfd,(struct sockaddr *)&their_addr,&sin_size))==-1){
perror("accept");
continue;
}
}
printf("server :got connection from%s",inet_ntoa(their_addr.sin_addr));
if(!fork()){
if(send(new_fd,"HELLO,WORLD",14,0)==-1){
perror("send");
close(new_fd);
exit(0);
}

close(new_fd);
waitpid(-1,NULL,WNOHANG)>0;
}
}



客户端
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>

#define PORT 3490
#define MAXDATASIZE 100

int main(int argc,char *argv[])
{
int sockfd,numbytes;
char buf[MAXDATASIZE];
struct hostent *he;
struct sockaddr_in their_addr;
if(argc!=2){
fprintf(stderr,"usage:client hostname");
exit(1);
}
if((he=gethostbyname(argv[1]))==NULL){
herror("gethostbyname");
exit(1);
}
if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1){
perror("socket");
exit(1);
}
their_addr.sin_family=AF_INET;
their_addr.sin_port=htons(PORT);
their_addr.sin_addr=*((struct in_addr *)he->h_addr);
bzero(&(their_addr.sin_zero),8);
if(connect(sockfd,(struct sockaddr *)&their_addr,sizeof(struct sockaddr))==-1) {
perror("connect");
exit(1);
}
if((numbytes=recv(sockfd,buf,MAXDATASIZE,0))==-1){
perror("recv");
exit(1);
}
buf[numbytes]=' ';
printf("Received :%s",buf);
close(sockfd);
return 0;
}








不知道为什么 自己在一台机器上执行服务端和客户端 执行客户端总是connect: Connection refused 没看出来～～～～
求助一下～～～～～～～～～～～～