tcpserver.c

tcp/Ip的程序

/*server.c*/

#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>

int port=8000;

int main(void)
{
  struct sockaddr_in sin;
  struct sockaddr_in pin;
  int    mysock;
  int    tempsock;
  int    addrsize;
  char   str[100],str1[20],str2[20],str3[20];
  char   buf[100];
  int    i,len1,len2,len3,len4,len5,len6;
  float  c;

   /*new  socket*/
    mysock= socket(AF_INET,SOCK_STREAM,0);
    if(mysock == -1)
     {
      perror("call to socket");
      exit(1);
     }
    /*new  IPV4*/
     bzero(&sin,sizeof(sin));           //zero成员并未使用，它是为了和通用套接字地址struct sockaddr兼容性而设定的。在编程中，一般都通过bzero()或将其置零。
     sin.sin_family = AF_INET;
//设置服务器套接字的IP地址为特殊值INADDR_ANY，表示服务器愿意接收来自任何网络设备接口的客户机连接。htonl()函数将主机顺序的字节转换成网络顺序的字节
     sin.sin_addr.s_addr = htonl(INADDR_ANY);
     sin.sin_port = htons(port);
     
     /*bind socket*/
     if(bind(mysock,(struct sockaddr *)&sin,sizeof(sin))==-1)
      {
     perror("call to bind");
     exit(1);
      }

      /*listen client */
     if(listen(mysock,20)==-1)
      {
      perror("call to listen");
      exit(1);
      }
      
     printf("accepting connections....\n");

     while(1)
      {
      /*receive client connection*/
      tempsock = accept(mysock,(struct sockaddr *)&pin ,&addrsize);
      if(tempsock ==-1){
        perror("call to accept");
         exit(1);
        }
       
      /*receive client message*/
      len1=recv(tempsock,str,100,0);
        printf("%d\n",len1);
        str[len1]=0;   
       printf("received from client %s\n",str);

       if(len1>0){
        strcpy(str1,strtok(str," "));           //strtok 分割字符串
         printf("the first string is %s\n",str1);
        strcpy(str2,strtok(NULL," "));
         printf("the second string is %s\n",str2);
        strcpy(str3,strtok(NULL," "));
         printf("the third string is %s\n",str3);
         c=atof(str3)*1.05;               //atof将字符串变为实数
          sprintf(buf,"the number is %s\n  the food is %s\n  the cost is %s\n ",str1,str2,str3);
 
       printf("%f\n",c);
       printf("%s",buf);
         }
        len2=strlen(buf);
       printf("%d\n",len2);
       if(send(tempsock,buf,len2,0)==-1);{
          perror("not to send");
         exit(1);
            }

        /*len5=send(tempsock,buf,len2,0);
        len3=recv(tempsock,str,100,0);
        printf("%d\n",len3);
        str[len3]=0;   
       printf("received from client %s\n",str);

      if(len3>0){
        strcpy(str1,strtok(str," "));           //strtok 分割字符串
         printf("the first string is %s\n",str1);
        strcpy(str2,strtok(NULL," "));
         printf("the second string is %s\n",str2);
        strcpy(str3,strtok(NULL," "));
         printf("the third string is %s\n",str3);
         //c=atof(str3)*1.05;               //atof将字符串变为实数
          sprintf(buf,"the number is %s\n  the food is %s\n  the cost is %s\n ",123,456,789);
         }
       len4=strlen(buf);
      if(send(tempsock,buf,len4,0)==-1);{
          perror("call to send");
         exit(1);
            }
        len6=send(tempsock,buf,len4,0);*/
         close(tempsock);
      }
        return 0;

}