1、如果有用户登录,其他用户可以收到这个人的登录信息
2、如果有人发送信息,其他用户可以收到这个人的群聊信息
3、如果有人下线,其他用户可以收到这个人的下线信息
4、服务器可以发送系统信息
服务器
#include<myhead.h>typedef struct Node
{char usrName[20];//用户名struct sockaddr_in cin;struct Node *next; //指针
}__link;//收发信息结构体
typedef struct msgtyp
{int type;char name[20];char text[128];
}msg;
int do_lodin(int sfd,__link* head,msg recv_msg,struct sockaddr_in cin)
{printf("%s[%s:%d]登陆成功\n",recv_msg.name,inet_ntoa(cin.sin_addr),ntohs(cin.sin_port));sprintf(recv_msg.text,"----%s登陆成功----",recv_msg.name);while(head->next!=NULL){head=head->next;if(sendto(sfd,&recv_msg,sizeof(recv_msg),0,(struct sockaddr*)&(head->cin),sizeof(head->cin))==-1){perror("sendto");return -1;}}//添加客户到链表__link *new=(__link*)malloc(sizeof(__link));new->cin=cin;new->next=NULL;head->next=new;return 0;
}
int do_chat(int sfd,__link* head, msg recv_msg, struct sockaddr_in cin)
{printf("%s[%s:%d]chat成功\n",recv_msg.name,inet_ntoa(cin.sin_addr),ntohs(cin.sin_port));char buf[258]="";sprintf(buf,"%s:%s",recv_msg.name,recv_msg.text);strcpy(recv_msg.text,buf);//给其他客户端发送消息while(head->next!=NULL){head=head->next;head->cin=cin;if(memcmp(&cin, &head->cin, sizeof(cin)) != 0){if(sendto(sfd,&recv_msg,sizeof(recv_msg),0,(struct sockaddr*)&(head->cin),sizeof(head->cin))==-1){perror("sendto");return -1;}}}return 0;
}
int do_quit(int sfd,__link* head, msg recv_msg, struct sockaddr_in cin)
{sprintf(recv_msg.text, "-----%s 已下线-----\n", recv_msg.name);while(head->next != NULL){if(memcmp(&cin, &head->next->cin, sizeof(cin)) == 0){//删除__link* temp = head->next;head->next = temp->next;free(temp);}else{head = head->next;if(sendto(sfd, &recv_msg, sizeof(recv_msg),0, (struct sockaddr*)&(head->cin), sizeof(head->cin))==-1){perror("sendto");return -1;}}}return 0;
}int main(int argc, char *argv[])
{if(argc<3){printf("请输入ip和端口号\n");return -1;}int sfd=socket(AF_INET,SOCK_DGRAM,0);if(sfd==-1){perror("socket");return -1;}int reuse=-1;if(setsockopt(sfd,SOL_SOCKET,SO_REUSEADDR,&reuse,sizeof(reuse))==-1){perror("setsockopt");return -1;}struct sockaddr_in sin;sin.sin_family=AF_INET;sin.sin_port=htons(atoi(argv[2]));sin.sin_addr.s_addr=inet_addr(argv[1]);if(bind(sfd,(struct sockaddr*)&sin,sizeof(sin))==-1){perror("bind");return -1;}//printf("bind success\n");int res=fork();//父进程接收消息if(res>0){__link *head=(__link*)malloc(sizeof(__link));head->next=NULL;msg recv_msg;int recv_len=0;struct sockaddr_in cin;socklen_t len=sizeof(cin);while(1){recv_len=recvfrom(sfd,&recv_msg,sizeof(recv_msg),0,(struct sockaddr*)&cin,&len);if(recv_len<0){perror("recvfrom");return -1;}int type=ntohl(recv_msg.type);switch(type){case 1:{do_lodin(sfd,head,recv_msg,cin);}break;case 2:{do_chat(sfd,head,recv_msg,cin);}break;case 3:{do_quit(sfd,head,recv_msg,cin);}break;}}}else if(res==0){//子进程,发送系统消息msg sys_msg={htonl(1),"**system**"};while(1){bzero(sys_msg.text,1024);fgets(sys_msg.text,1024,stdin);sys_msg.text[strlen(sys_msg.text)-1]=0;if(sendto(sfd,&sys_msg,sizeof(sys_msg),0,(struct sockaddr*)&sin,sizeof(sin))==-1){perror("sendto");return -1;}}printf("系统消息发送成功\n");}close(sfd);return 0;
}
客户端代码
#include<myhead.h>
#define LOGIN 1
#define CHAT 2
#define QUIT 3
#define ERR_LOG(msg) do{\printf("%d %s %s \n", __LINE__, __func__, __FILE__);\perror(msg);\
}while(0)//收发信息的结构体
typedef struct
{int type;char name[20];char text[128] ;}MSG;typedef void (*sighandler_t)(int);int do_chat(int sfd, MSG msg, struct sockaddr_in sin)
{while(1){//从终端获取聊天信息bzero(msg.text, 128);fgets(msg.text, 128,stdin);msg.text[strlen(msg.text)-1] = 0;if(strncasecmp(msg.text, "QUIT",4) == 0){msg.type = htonl(QUIT);}else{msg.type = htonl(CHAT);}//发送 if(sendto(sfd, &msg, sizeof(msg), 0, (void*)&sin, sizeof(sin)) < 0){ERR_LOG("sendto");return -1;}//如果是退出信息,则客户端要退出if(msg.type == htonl(QUIT)){exit(0); //退出子进程;}}
}int do_recv(int sfd)
{MSG rcv_msg ;while(1){if(recvfrom(sfd, &rcv_msg, sizeof(rcv_msg), 0, NULL, NULL) < 0){perror("recvfrom");return -1;}printf("%s\n",rcv_msg.text);}
}void handler(int sig)
{//回收子进程资源并退出while(waitpid(-1,NULL, WNOHANG)>0);exit(0);
}int main(int argc, char *argv[])
{if(argc < 3){ printf("请输入 ip 和端口号\n");return -1; } sighandler_t s = signal(SIGCHLD, handler);if(s == SIG_ERR){ERR_LOG("signal");return -1;}int sfd = socket(AF_INET, SOCK_DGRAM, 0);if(sfd < 0){perror("socket");return -1;}//2.填充服务器ip和端口号 struct sockaddr_in sin;sin.sin_family=AF_INET;sin.sin_port=htons(atoi(argv[2]));sin.sin_addr.s_addr=inet_addr(argv[1]);socklen_t addrlen = sizeof(sin);//登录协议MSG msg ;msg.type = htonl(1);printf("请输入姓名>>>");fgets(msg.name, 20, stdin);msg.name[strlen(msg.name)-1] = 0;if(sendto(sfd, &msg, sizeof(msg), 0, (void*)&sin, sizeof(sin)) < 0){ERR_LOG("sendto"); return -1;}pid_t pid = fork();if(pid > 0){//父进程获取信息do_recv(sfd);}else if(0 == pid){//子进程发送信息do_chat(sfd, msg, sin);}//4.关闭套接字close(sfd);return 0;
}
效果