Linux TCP编程问题

刚学linux 网络编程，写了个小程序：为什么运行到服务器端的recv处就阻塞了呢？苦苦找了好久，真的快崩溃了。。。
求助了！

#include <stdio.h>   
#include <string.h>   
#include <sys/socket.h>   
#include <netinet/in.h>   
#include <sys/types.h>   
#include <unistd.h>   
#define MAX_BUF 50   
#define PORT 8300   
  
int main(void)  
{  
    int serverfd,clientfd;  
    struct sockaddr_in saddr,caddr;  
    char buf[30];  
    socklen_t slen,clen;  
    char sendbuf[]="hello";  
  
    bzero(&saddr,sizeof(saddr));  
    serverfd=socket(AF_INET,SOCK_STREAM,0);  
    if(serverfd<0)  
    {  
      printf("can not create socket in server!\n");  
      return -1;  
    }  
    //bzero(&saddr,sizeof(saddr));     
    saddr.sin_family=AF_INET;  
    saddr.sin_port=htons(PORT);  
    saddr.sin_addr.s_addr=htonl(INADDR_ANY);  
      
    slen=sizeof(saddr);  
    bind(serverfd,(struct sockaddr* )&saddr,slen);  
    listen(serverfd,10);  
    printf("wait for connect!\n");  
    while(1)  
    {  
      clen=sizeof(caddr);  
      clientfd=accept(serverfd,(struct sockaddr*)&caddr,&clen);  
            
     //int se=send(clientfd,sendbuf,sizeof(sendbuf)+1,0);   
    // printf("\nSend message %d.\n",se);   
  
    printf("Server receive ing...\n");  
    memset(buf,0,30);  
    int re= recv(clientfd,buf,30,0);  
    if (re<0)  
    {  
       printf("Server receive failed!\n");  
       return -1;  
    }  
    else  
    printf("\n%d,",re);  
      
     //buf[strlen(buf)]='\0';   
     printf("%s",buf);    
       
     sleep(3);  
     close(clientfd);  
    }  
    //close(serverfd);   
} 

客户端：

#include <stdio.h>   
#include <string.h>   
#include <sys/socket.h>   
#include <netinet/in.h>   
#include <sys/types.h>   
#include <unistd.h>   
#define MAX_BUF 50   
#define PORT 8300   
  
int main()  
{  
    int sockfd,newsockfd;  
        int len;  
    struct sockaddr_in addr;  
    char cbuf[]="Client";  
    char rbuf[255];  
    int buflen;  
  
    bzero(&addr,sizeof(addr));  
    sockfd=socket(AF_INET,SOCK_STREAM,0);  
    addr.sin_family=AF_INET;  
    inet_pton(AF_INET,"127.0.0.1",&addr.sin_addr);  
    //addr.sin_addr.s_addr=htons(INADDR_ANY);   
    addr.sin_port=htons(PORT);  
      
    len=sizeof(addr);  
    newsockfd=connect(sockfd,(struct sockaddr*)&addr,len);  
    if(-1==newsockfd)  
    {  
      printf("connect failed!\n");  
      return -1;  
    }  
    //recv(sockfd,rbuf,255,0);   
    //printf("\n The receive message is:%s\n",rbuf);    
 
    //sleep(1);   
  
    buflen=strlen(cbuf);  
    printf("\n The Client message is:%d\n",buflen);  
        int se=send(sockfd,cbuf,buflen+1,0);  
    printf("Client Send message %d.\n",se);  
    sleep(3);  
      
      
        close(sockfd);  
    return 0;  
  
}  

如果只是去掉while的话 就只能接收一个客户端的连接了

最好还是弄个select函数比较靠谱一点，立马返回，或者加时间阻塞