tcps.c

Linux下使用C编程

#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>

int main(int argc, char *argv[]) 
{ 
 int sockfd,new_fd; 
 struct sockaddr_in server_addr; 
 struct sockaddr_in client_addr; 
 int sin_size,portnumber; 
 char hello[]="Hello! Are You Fine?\n"; 


 portnumber=6868;
/* 服务器端开始建立socket描述符 */ 
 if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1)   
 { 
        fprintf(stderr,"Socket error:%s\n\a",strerror(errno)); 
        exit(1); 
 } 

/* 服务器端填充 sockaddr结构  */  
 bzero(&server_addr,sizeof(struct sockaddr_in)); 
 server_addr.sin_family=AF_INET; 
 server_addr.sin_addr.s_addr=htonl(INADDR_ANY); 
 server_addr.sin_port=htons(portnumber); 
  
/* 捆绑sockfd描述符  */  
 if(bind(sockfd,(struct sockaddr *)(&server_addr),sizeof(struct sockaddr))==-1) 
 { 
        fprintf(stderr,"Bind error:%s\n\a",strerror(errno)); 
        exit(1); 
 } 
  
/* 监听sockfd描述符  */ 
 if(listen(sockfd,5)==-1) 
 { 
        fprintf(stderr,"Listen error:%s\n\a",strerror(errno)); 
        exit(1); 
 } 

 while(1) 
 { 
        /* 服务器阻塞,直到客户程序建立连接  */ 
        sin_size=sizeof(struct sockaddr_in); 
        if((new_fd=accept(sockfd,(struct sockaddr *)(&client_addr),&sin_size))==-1) 
        { 
                fprintf(stderr,"Accept error:%s\n\a",strerror(errno)); 
                exit(1); 
    } 

        fprintf(stderr,"Server get connection from %s\n", 
                                        inet_ntoa(client_addr.sin_addr)); 
	int numbytes;
        char tmp[300];
	if ((numbytes=recv(new_fd, tmp, sizeof(tmp), 0)) == -1) { 
        perror("recv"); 
        exit(1); 
   	 } 
        char type[5];
        memcpy(type,tmp,4);
	type[4]=0;
        printf("numbytes is %d,recieve :%s\n",numbytes,tmp); 
	printf("type is :%s\n",type); 
        int plant;
        memcpy(&plant,tmp+4,4);
	printf("plant is :%d\n",plant); 
	int unit;
	memcpy(&unit,tmp+8,4);
	printf("unit is :%d\n",unit); 
        fflush(stdout);
       /*if(write(new_fd,hello,strlen(hello))==-1) 
        { 
         fprintf(stderr,"Write Error:%s\n",strerror(errno)); 
         exit(1); 
        } */
        
/* 这个通讯已经结束     */ 
        close(new_fd); 
/* 循环下一个     */   
  } 
 close(sockfd); 
 exit(0); 
}