socket 实现简单的计算器

野性酷女 2022-06-03 00:38 245阅读 0赞

**socket 实现简单的的计算器**

服务端  server.c  对客户端的请求进行处理,并返回结果

客户端  client.c  向服务端发送一个表达式 如 add 1  2 表示 1+2 服务器返回结果;

主要功能 +  - \*  / echo

代码:server.c

#include<stdio.h>
    #include<stdlib.h>
    #include<string.h>
    #include<errno.h>
    #include<unistd.h>
    #include<sys/un.h>
    #include<sys/socket.h>
    #include<sys/wait.h>
    #include<sys/types.h>
    #include<netdb.h>
    #include<signal.h>
    #include<ctype.h>
    
    
    #define PORT  5000
    //获取子进程退出信号 在退出时给出提示信息
    void sig_handler(int signo)
    {
     pid_t pid;
     int stat;
     pid = waitpid(-1,&stat,WNOHANG);
      while(pid>0){
      printf("child process terminated (PID: %ld)\n",(long)getpid()); 
      pid = waitpid(-1,&stat,WNOHANG);
      }
    return;
    }
    typedef struct{
    		double a;
    		double b;
    		char s[10];
    		char echo_buf[1024];
    }Mes;
    
    
    int main(int argc ,char *argv[])
    {
    		socklen_t clt_addr_len;
    		int listen_fd;
    		int com_fd;
    		int i;
    		static char send_buf[1024];
    		int len;
    		int port;
    		pid_t pid;
    
    
    		struct sockaddr_in clt_addr;
    		struct sockaddr_in srv_addr;
    		if(argc!=1)
    		{
    				printf("Usage: %s  port\n",argv[0]);
    				exit(1);
    		}
    
    		if(signal(SIGCHLD,sig_handler) < 0){
    				perror("can not set the signal\n");
    				exit(1);
    		}
    		listen_fd = socket(PF_INET,SOCK_STREAM,0);
    		if(listen_fd < 0){
    				perror("can not create listening socket\n");
    				exit(1);
    		}
    		memset(&srv_addr,0,sizeof(srv_addr));
    		srv_addr.sin_family = AF_INET;
    	    srv_addr.sin_addr.s_addr = htonl(INADDR_ANY);	
    		srv_addr.sin_port = htons(PORT);
    
    		int t=bind(listen_fd,(struct sockaddr*)&srv_addr,sizeof(srv_addr));		 
                   if(t==-1){
    				perror("can not bind server socket\n");
    				exit(1);
    		}
    		
    		t=listen(listen_fd,20);
    		if(t==-1){
    				perror("can not listen the client connect request\n");
    				close(listen_fd);
    		}
    		memset(send_buf,0,1024);
    		while(1)
    		{
    				len = sizeof(clt_addr);
    				com_fd = accept(listen_fd,(struct sockaddr*)&clt_addr,&len);
    				if(com_fd < 0){
    						if(errno == EINTR){
    								continue;
    						}
    						else{
    								perror("can not accept client connect request\n");
    								close(listen_fd);
    								exit(1);
    						}
    				}
    				pid = fork();
    				if(pid < 0){
    						perror("can not create the child process\n ");
    						close(listen_fd);
    						exit(1);
    				}else if(pid == 0){
    						Mes mes;
    						int n=sizeof(mes);
    
    
    						
    						while((len = read(com_fd,&mes,n))>0){
    
    
    								if(strcmp(mes.s,"echo")!=0){
    								printf("Message from client(%d):%s %.2lf %.2lf\n",len,mes.s,mes.a,mes.b);
    								if(send_buf[0]=='@'){
    										break;
    								}
    								
    								double result =  0;
    								if(strcmp(mes.s,"add")==0){
    										printf("加法\n");
    										result = mes.a+mes.b;
    								}else if(strcmp(mes.s,"sub")==0){
    										printf("减法\n");
    										result = mes.a - mes.b;
    								}else if(strcmp(mes.s,"mul")==0){
    										printf("乘法\n");
    										result = mes.a * mes.b;
    								}else if(strcmp(mes.s,"div")==0){
    										printf("除法\n");
    										if(mes.b == 0){
    												printf("除数为0\n ");
    												result == 0;
    										}else{
    												result = mes.a / mes.b;
    										}
    								}else{
    										printf("不识别的操作\n");
    								}
    								printf("结果:result = %.2lf\n",result);
    								if(mes.b == 0 && (strcmp(mes.s,"div") == 0)){
    										sprintf(send_buf,"%s","除数为0 无意义\n");
    								}else{
    								sprintf(send_buf,"%.2lf",result);
    								}
    							}else{
    									printf("客户端的消息:%s\n",mes.echo_buf);
    									printf("回复的消息");
    									fgets(send_buf,1024,stdin);
    							}
    
    
    								write(com_fd,send_buf,strlen(send_buf));
    								
    						}
    								close(com_fd);
    								return 0;
    						}else{
    								close(com_fd);
    						}
    		}
    
    
    			return 0;
    }

client.c:

#include<stdio.h>
    #include<stdlib.h>
    #include<string.h>
    #include<sys/types.h>
    #include<sys/socket.h>
    #include<sys/un.h>
    #include<unistd.h>
    #include<netdb.h>
    #include<errno.h>
    #include<arpa/inet.h>
    
    
    #define PORT  5000
    
    
    typedef struct{
    		double a;
    		double b;
    		char s[10];
    		char echo_buf[1024];
    }Mes;
    int main(int argc,char *argv[])
    {
    		int connect_fd;
    		int ret;
    		char recv_buf[1024];
    		int i;
    		int port;
    		int len;
    
    
    		static struct sockaddr_in srv_addr;
    
    		if(argc!=1){
    				printf("Usage: %s server_ip_address port \n",argv[0]);
    				exit(1);
    		}
    
    		connect_fd = socket(PF_INET,SOCK_STREAM,0);
    		if(connect_fd < 0){
    				perror("can not create communication socket\n");
    				exit(1);
    		}
    
    
    		memset(&srv_addr,0,sizeof(srv_addr));
    		srv_addr.sin_family = AF_INET;
    		srv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    		srv_addr.sin_port = htons(PORT);
    
    		if((connect(connect_fd,(struct sockaddr*)&srv_addr,sizeof(srv_addr)))==-1){
    				perror("can not to the server\n");
    				close(connect_fd);
    				exit(1);
    		}
    
    
    		memset(recv_buf,0,1024);
    
    
    		while(1){
    				
    				Mes mes;
    				int n=sizeof(mes);
    				printf("请输入表达式:\n");
    				scanf("%s",mes.s);
    				if(strcmp(mes.s,"echo")==0){
    						fgets(mes.echo_buf,1024,stdin);
    						mes.a = 0;
    						mes.b = 0;
    				}else{
    				scanf("%lf%lf",&mes.a,&mes.b);
    				sprintf(mes.echo_buf,"%s","NULL");
    				}
    				write(connect_fd,&mes,n);
    				len = read(connect_fd,recv_buf,n);
    				if(strcmp(mes.s,"echo")==0){
    						printf("服务端回复的消息:%s\n",recv_buf);
    				}else if(len > 0){
    						double result;
    						sscanf(recv_buf,"%lf",&result);
    						printf("计算的结果: %.2lf\n",result);
    				
    				if(recv_buf[0] == '@')
    						break;
    		}
    		}
    		close(connect_fd);
    		return 0;
    }

运行结果截图:

server:

![Center][]

client:

![Center 1][]

[Center]: /images/20220603/a6444d19cb6c4aa4969420f1e62a6ddd.png
[Center 1]: /images/20220603/5ca0644c156f449c84ad0488e11680b6.png