UDP聊天室

服务器端

#include <myhead.h>#define SER_IP "192.168.124.38"
#define SER_PORT 8888
#define RBUFSIZE 128
#define WBUFSIZE 128typedef struct node{char usrName[20];struct sockaddr_in cli_sockaddr;struct node* next;
}node, *node_p;node_p create_head_node();
node_p create_node(char* usrName, struct sockaddr_in cli_sockaddr);
void insert_tail(node_p H, char* usrName, struct sockaddr_in cli_sockaddr);
char* find(node_p H, struct sockaddr_in cli_sockaddr);
void delete(node_p H, struct sockaddr_in cli_sockaddr);int main(int argc, const char *argv[]){int sockfd;struct sockaddr_in ser_sockaddr;struct sockaddr_in cli_sockaddr;char wbuf[WBUFSIZE]={0};char rbuf[RBUFSIZE]={0};socklen_t addrlen = sizeof(struct sockaddr);struct pollfd pfds[2];// 创建头结点node_p H = create_head_node();sockfd = socket(AF_INET, SOCK_DGRAM, 0);if(sockfd == -1){perror("socket");return -1;}ser_sockaddr.sin_family = AF_INET;ser_sockaddr.sin_port = htons(SER_PORT);ser_sockaddr.sin_addr.s_addr = inet_addr(SER_IP);if(bind(sockfd, (struct sockaddr*)&ser_sockaddr, sizeof(struct sockaddr)) == -1){perror("bind");return -1;}pfds[0].fd = 0;pfds[0].events = POLLIN;pfds[1].fd = sockfd;pfds[1].events = POLLIN;puts("Waiting for client connection...");//开始通信while (1) {poll(pfds, 2, -1);// 接受客户端发送的消息，并转发给其他客户端if (pfds[1].revents == POLLIN) {memset(rbuf, 0, sizeof(rbuf));recvfrom(sockfd, rbuf, RBUFSIZE, 0, (struct sockaddr*)&cli_sockaddr, &addrlen);// 判断客户端是否在链表内，即客户端是否已经连接char* ret = find(H, cli_sockaddr);// 用户未存在于链表中if (ret == NULL) {// 在客户端首次连接时，利用链表尾插存储客户端的用户名和地址信息insert_tail(H, rbuf, cli_sockaddr);// 服务器端输出客户端加入消息printf("%s [%s:%d] 加入聊天室\n", rbuf, inet_ntoa(cli_sockaddr.sin_addr), ntohs(cli_sockaddr.sin_port));// 将客户端上线的消息，发送给出了除了刚刚加入的客户端的所有主机node_p temp = H->next;//格式化客户端登录的消息char str[1024]={0};sprintf(str, "----%s加入聊天室----", rbuf);while (temp->next != NULL) {if (sendto(sockfd, str, strlen(str), 0, (struct sockaddr*)&temp->cli_sockaddr, sizeof(struct sockaddr)) == -1) {perror("sendto");}temp = temp->next;}}// 用户存在于链表中else if (ret > 0) {// 已登录客户端发送了退出信号，通知服务器以及其他所有用户if(strcmp(rbuf, "quit") == 0){// 格式化客户端退出消息char str[1024]={0};sprintf(str, "----%s退出聊天室----", ret);// 服务器端输出客户端退出消息printf("%s [%s:%d] 退出聊天室\n", ret, inet_ntoa(cli_sockaddr.sin_addr), ntohs(cli_sockaddr.sin_port));// 通知其他人node_p temp = H->next;while (temp != NULL) {if (sendto(sockfd, str, strlen(str), 0, (struct sockaddr*)&temp->cli_sockaddr, sizeof(struct sockaddr)) == -1) {perror("sendto");}temp = temp->next;}// 将退出的客户端从链表中删除delete(H, cli_sockaddr);}else{// 将客户端发送的消息转发给所有人（除了发送消息的客户端）// 格式化用户发送的消息char str[1024]={0};sprintf(str, "%s: %s", ret, rbuf);node_p temp = H->next;while (temp != NULL) {if (temp->cli_sockaddr.sin_addr.s_addr == cli_sockaddr.sin_addr.s_addr && temp->cli_sockaddr.sin_port == cli_sockaddr.sin_port){temp = temp->next;continue;}if (sendto(sockfd, str, strlen(str), 0, (struct sockaddr*)&temp->cli_sockaddr, sizeof(struct sockaddr)) == -1) {perror("sendto");}temp = temp->next;}printf("%s [%s:%d] 发送了一条消息\n", ret, inet_ntoa(cli_sockaddr.sin_addr), ntohs(cli_sockaddr.sin_port));}}}// 服务器向所有客户端发送消息if (pfds[0].revents == POLLIN) {memset(wbuf, 0, sizeof(wbuf));fgets(wbuf, sizeof(wbuf), stdin);wbuf[strlen(wbuf)-1] = 0;// 格式化服务器发送的消息char str[1024]={0};sprintf(str, "server: %s", wbuf);node_p temp = H->next;while (temp != NULL) {if (sendto(sockfd, str, strlen(str), 0, (struct sockaddr*)&temp->cli_sockaddr, sizeof(struct sockaddr)) == -1) {perror("sendto");}temp = temp->next;}printf("服务器 [%s:%d] 发送了一条消息\n",inet_ntoa(ser_sockaddr.sin_addr), ntohs(ser_sockaddr.sin_port));}}//关闭socketclose(sockfd);return 0;
}node_p create_head_node(){                                    node_p H=(node_p)malloc(sizeof(node));if(H==NULL){printf("空间申请失败\n");return NULL;}H->next=NULL;return H;
}node_p create_node(char* usrName, struct sockaddr_in cli_sockaddr){node_p p=(node_p)malloc(sizeof(node));if(p==NULL){printf("空间申请失败\n");return NULL;}strcpy(p->usrName, usrName);p->cli_sockaddr = cli_sockaddr;return p;
}void insert_tail(node_p H, char* usrName, struct sockaddr_in cli_sockaddr){if(H==NULL){printf("入参为空\n");return;}node_p p=H;while(p->next!=NULL){p=p->next;}node_p new = create_node(usrName, cli_sockaddr);new->next=p->next;p->next=new;
}/*   @brief  判断客户端信息是否已经保存在链表内@param  H 头结点cli_sockaddr 待判断的客户端信息@retval NULL 客户端信息不在链表内非空 客户端的用户名字符串指针
*/char* find(node_p H, struct sockaddr_in cli_sockaddr){if (H == NULL){printf("入参为空\n");return NULL;}if (H->next == NULL){// 链表为空return NULL;}node_p temp = H->next;while (temp != NULL){if (temp->cli_sockaddr.sin_addr.s_addr == cli_sockaddr.sin_addr.s_addr && temp->cli_sockaddr.sin_port == cli_sockaddr.sin_port){return temp->usrName;}temp = temp->next; }return NULL;
}/*   @brief  删除链表中指定的客户端信息@param  H 头结点cli_sockaddr 待删除的客户端信息@retval 无
*/void delete(node_p H, struct sockaddr_in cli_sockaddr){if (H == NULL){printf("入参为空\n");return;}node_p temp = H;while (temp->next->cli_sockaddr.sin_addr.s_addr != cli_sockaddr.sin_addr.s_addr || \temp->next->cli_sockaddr.sin_port != cli_sockaddr.sin_port)temp = temp->next;node_p p = temp->next;temp->next = temp->next->next;free(p);
}

客户端

#include <myhead.h>#define SER_PORT 8888
#define SER_IP "192.168.124.38"
#define CLI_PORT 6666
#define CLI_IP "192.168.125.117"
#define WBUFSIZE 128
#define RBUFSIZE 128int main(int argc, const char *argv[])
{int sockfd;char wbuf[WBUFSIZE] ={0};char rbuf[RBUFSIZE] ={0};struct sockaddr_in ser_sockaddr;struct pollfd pfds[2];sockfd = socket(AF_INET, SOCK_DGRAM, 0);if(sockfd == -1){perror("socket");return -1;}ser_sockaddr.sin_family = AF_INET;ser_sockaddr.sin_port = htons(SER_PORT);ser_sockaddr.sin_addr.s_addr = inet_addr(SER_IP);pfds[0].fd = 0;pfds[0].events = POLLIN;pfds[1].fd = sockfd;pfds[1].events = POLLIN;printf("请输入聊天昵称->");fflush(stdout);//开始通信while(1){// 通信缓冲区memset(wbuf, 0, sizeof(wbuf));memset(rbuf, 0, sizeof(rbuf));// 阻塞等待事件发生poll(pfds, 2, -1);// 向服务器端发送消息if(pfds[0].revents == POLLIN){fgets(wbuf, sizeof(wbuf), stdin);wbuf[strlen(wbuf)-1] = 0;sendto(sockfd, wbuf, strlen(wbuf), 0, (struct sockaddr*)&ser_sockaddr, sizeof(struct sockaddr));if(strcmp(wbuf, "quit") == 0){close(sockfd);return 0;}}// 接收服务器消息if(pfds[1].revents == POLLIN){recvfrom(sockfd, rbuf, sizeof(rbuf), 0,NULL, NULL);printf("%s\n", rbuf);}}return 0;
}