server.c.txt

这是一款很通用的linux下的TCP通讯编程。适合于嵌入式linux平台网络编程的开发等相关研究。

//该程序对每一个连接的客户端直接发送“Hello，world！ \n”.
#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<errno.h>
#include<string.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<sys/wait.h>
#include<signal.h>

#define MYPORT 3490 //the port users will be connecting to
#define BACKLOG 10  //how many pending connnections queue will hold
  void sigchld_handler(int s){
    while(wait(NULL)>0);
  }

int main(void){
   int sockfd,new_fd;//listen on sock_fd,new connection on new_fd
   struct sockaddr_in my_addr;//my address information 
   int sin_size;
   struct sigaction sa;
   int yes=1;
if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1){
    perror("socket");
    exit(1);
    }
my_addr.sin_family=AF_INET;//host byte order
my_addr.sin_port=htons(MYPORT);//short,network byte order
my_addr.sin_addr.s_addr=INADDR_ANY;//automatically fill with my IP
memset(&(my_addr.sin_zero),'\0',8);//zero the rest of the struct
if(bind(sockfd,(stuct sockaddr*)&my_addr,sizeof(struct sockaddr))==-   1){
   perror("bind");
   exit(1);
   }
if(listen(sockfd,BACKLOG)==-1){
   perror("listen");
   exit(1);
   }
sa.sa_handler=sigchld_handler;//reap all dead processes
sigemptyset(&sa.sa_mask);
sa.sa_flags=SA_RESTART;
if(sigaction(SIGCHLD,&sa,NULL)==-1){
  perror("sigaction");
  exit(1);
  }
while(1){//main accept() loop 
  sin_size=sizeof(struct sockaddr_in);
  if((new_fd=accept(sockd,(struct sockaddr*)&their_addr,&sin_size))     ==-1){
     perror("accept");
     continue;
     }
   printf("server:got connection from %s\n",inet_ntoa         (theit_addr.sin_addr));
   if(!fork()){//this is the child process
      close(sockfd);//child doesn't need the listener
      if(send)(new_fd,"Hello,world!\n"),14,0)==-1){
          perror("send");
          close(new_fd);
          exit(0);
          }
        
      close(new_fd);//parent doesn't need this
     }
     //}
  return 0;
}