UDP简单实现并发服务器和客户端简单通信

墨蓝 2022-07-14 09:40 225阅读 0赞

以下程序均未做错误处理，以后有时间一定补上

客户端

#include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <netinet/in.h>
    #include <sys/socket.h>
    
    int main(int argc,char **argv)
    {
    	int sockfd;
    	int n;
    	struct sockaddr_in servaddr;
    	char readbuf[1000];
    	char sendbuf[1000];
    
    	sockfd = socket(AF_INET,SOCK_DGRAM,0);
    	bzero(&servaddr,sizeof(servaddr));
    
    	servaddr.sin_family = AF_INET;
    	servaddr.sin_addr.s_addr = inet_addr(argv[1]);
    	servaddr.sin_port = htons(3200);
    
    	while(fgets(sendbuf,1000,stdin) != NULL)
    	{
    		sendto(sockfd,sendbuf,strlen(sendbuf),0,(struct sockaddr *)&servaddr,sizeof(servaddr));
    		n = recvfrom(sockfd,readbuf,1000,0,NULL,NULL);
    
    		readbuf[n] = '\0';
    		fputs(readbuf,stdout);
    	}
    
    	close(sockfd);
    
    	return 0;
    }

服务器

#include <stdio.h>
    #include <string.h>
    #include <stdlib.h>
    #include <netinet/in.h>
    #include <sys/socket.h>
    
    void strlwr(char *str)
    {
    	char *p;
    	p = str;
    
    	while(*p != '\0')
    	{
    		if((*p >= 'a') && (*p <= 'z'))
    		{
    			*p -= 32;
    		}
    
    		p++;
    	}
    }
    
    int main()
    {
    	int sockfd;
    	int n;
    	struct sockaddr_in servaddr,cliaddr;
    	char mesg[1000];
    	socklen_t clilen;
    
    	sockfd = socket(AF_INET,SOCK_DGRAM,0);
    	bzero(&servaddr,sizeof(servaddr));
    	servaddr.sin_family = AF_INET;
    	servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    	servaddr.sin_port = htons(3200);
    
    	bind(sockfd,(struct sockaddr*)&servaddr,sizeof(servaddr));
    
    	clilen = sizeof(cliaddr);
    
    	for(;;)
    	{
    		for(;;)
    		{
    			n = recvfrom(sockfd,mesg,1000,0,(struct sockaddr*)&cliaddr,&clilen);
    
    			if(n == 0)
    			{
    				printf("client closed");
    				exit(-1);
    			}
    
    			printf("******************\n");
    			mesg[n] = '\0';
    			printf("%s\n",mesg);
    			printf("*******************\n");
    
    			strlwr(mesg);
    			
    			sendto(sockfd,mesg,n,0,(struct sockaddr*)&cliaddr,sizeof(cliaddr));
    		}
    
    		//close(sockfd);
    	}
    
    	close(sockfd);
    
        return 0;
    }