#include <stdio.h>#include <stdlib.h>#include <string.h>#include <sys/types.h>#include <sys/socket.h>#include <arpa/inet.h>#include <unistd.h>#include <signal.h>#define CLIENT_LOGIN 100#define CLIENT_CHAT 200#define CLIENT_QUIT 300#define SERVER_CHA T 400#define SERVER_QUIT 500struct node{char name[20];struct sockaddr_in client_addr;struct node *next;};struct message{long type;char name[20];char mtext[512];};struct node *create_list(void);void insert_list(struct node *, char *, struct sockaddr_in *);void delete_list(struct node *, char *);void recv_message(int , struct node *);void send_message(int , struct sockaddr_in *, pid_t );void client_login(int , struct node *, struct message *, struct sockaddr_in *); void client_chat(int , struct node *, struct message *);void client_quit(int , struct node *, struct message *);void server_chat(int , struct node *, struct message *);void server_quit(int , struct node *, struct message *);void brocast_msg(int , struct node *, struct message *);void father_func(int sig_no){return ;}int main(int argc, const char *argv[]){int socket_fd;pid_t pid;struct sockaddr_in server_addr;struct node *head;if (argc < 3){fprintf(stderr, "usages : %s ip port\n", argv[0]);exit(-1);}if ((socket_fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0){perror("failed to create socket");exit(-1);}head = create_list();server_addr.sin_family = AF_INET;server_addr.sin_port = htons(atoi(argv[2]));server_addr.sin_addr.s_addr = inet_addr(argv[1]);if (bind(socket_fd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {perror("failed to bind");exit(-1);}if ((pid = fork()) < 0) //创建子经常{perror("failed to fork pid");exit(-1);}if (pid == 0)recv_message(socket_fd, head);elsesend_message(socket_fd, &server_addr, pid);return 0;}struct node *create_list(void){struct node *head;head = (struct node *)malloc(sizeof(struct node));head->next = NULL;return head;}void insert_list(struct node *head, char *name, struct sockaddr_in *client_addr) {struct node *new;new = (struct node *)malloc(sizeof(struct node));strcpy(new->name, name);new->client_addr = *client_addr;new->next = head->next;head->next = new;return ;}void delete_list(struct node *head, char *name){struct node *p = head->next;struct node *q = head;while (p != NULL){if (strcmp(p->name, name) == 0)break;p = p->next;q = q->next;}q->next = p->next;p->next = NULL;free(p);return ;}void recv_message(int socket_fd, struct node *head){struct message msg;struct sockaddr_in client_addr;int client_addrlen = sizeof(struct sockaddr);while (1){if (recvfrom(socket_fd, &msg, sizeof(msg), 0, (struct sockaddr *)&client_addr, &client_addrlen) < 0){perror("failed to recvform client");exit(-1);}switch(msg.type){case CLIENT_LOGIN:client_login(socket_fd, head, &msg, &client_addr);break;case CLIENT_CHA T:client_chat(socket_fd, head, &msg);break;case CLIENT_QUIT:client_quit(socket_fd, head, &msg);break;case SERVER_CHA T:server_chat(socket_fd, head, &msg);break;case SERVER_QUIT:server_quit(socket_fd, head, &msg);break;default:break;}}return ;}void send_message(int socket_fd, struct sockaddr_in *server_addr, pid_t pid){struct message msg;char buf[512];signal(getppid(), father_func);while (1){usleep(500);printf(">");fgets(buf, sizeof(buf), stdin);buf[strlen(buf) - 1] = 0;strcpy(msg.mtext, buf);strcpy( , "server");msg.type = SERVER_CHA T;if (strncmp(buf, "quit", 4) == 0){msg.type = SERVER_QUIT;if (sendto(socket_fd, &msg, sizeof(msg), 0,(struct sockaddr *)server_addr, sizeof(struct sockaddr)) < 0) {perror("failed to send server_quit message");exit(-1);}pause();kill(pid, SIGKILL);waitpid(pid, NULL, 0);exit(0);}if (sendto(socket_fd, &msg, sizeof(msg), 0, (struct sockaddr *)server_addr, sizeof(struct sockaddr)) < 0){perror("failed to send server_chat message");exit(-1);}}return ;}void client_login(int socket_fd, struct node *head, struct message *msg, struct sockaddr_in *client_addr){printf("********Login In********\n");printf("%s is Login In\n", msg->name);printf("************************\n");insert_list(head, msg->name, client_addr);brocast_msg(socket_fd, head, msg);return ;}void client_chat(int socket_fd, struct node *head, struct message *msg){printf("********Group Chat********\n");printf("name: %s\n", msg->name);printf("msg: %s\n", msg->mtext);printf("**************************\n");brocast_msg(socket_fd, head, msg);return ;}void client_quit(int socket_fd, struct node *head, struct message *msg){printf("*********Quit Msg********\n");printf("%s is Quit\n", msg->name);printf("*************************\n");delete_list(head, msg->name);brocast_msg(socket_fd, head, msg);return ;}void server_chat(int socket_fd, struct node *head, struct message *msg){printf("********Server Msg*********\n");printf("msg: %s\n", msg->mtext);printf("***************************\n");brocast_msg(socket_fd, head, msg);return ;}void server_quit(int socket_fd, struct node *head, struct message *msg){brocast_msg(socket_fd, head, msg);kill(getppid(), SIGUSR1);return ;}void brocast_msg(int socket_fd, struct node *head, struct message *msg){struct node *p = head->next;while(p != NULL){if (msg->type == CLIENT_LOGIN){if (strcmp(p->name, msg->name) == 0){p = p->next;continue;}}sendto(socket_fd, msg, sizeof(struct message), 0, (struct sockaddr *)&(p->client_addr), sizeof(struct sockaddr));p = p->next;}return ; }#include <stdio.h>#include <stdlib.h>#include <string.h>#include <sys/types.h>#include <sys/socket.h>#include <arpa/inet.h>#include <unistd.h>#include <signal.h>#define CLIENT_LOGIN 100#define CLIENT_CHAT 200#define CLIENT_QUIT 300#define SERVER_CHA T 400#define SERVER_QUIT 500struct message{long type;char name[20];char mtext[512];};void recv_message(int );void send_message(int , struct sockaddr_in *, char *, pid_t);void login_msg(struct message *);void group_msg(struct message *);void quit_msg(struct message *);void server_msg(struct message *);void server_quit(void);int main(int argc, char *argv[]){pid_t pid;int server_fd;struct sockaddr_in server_addr;if (argc < 4){fprintf(stderr, "usages: %s ip port name\n", argv[0]);exit(-1);}if ((server_fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0){perror("failed to create server_fd");exit(-1);}server_addr.sin_family = AF_INET;server_addr.sin_port = htons(atoi(argv[2]));server_addr.sin_addr.s_addr = inet_addr(argv[1]);if ((pid = fork()) < 0){perror("failed to fork pid");exit(-1);}if (pid == 0)recv_message(server_fd);elsesend_message(server_fd, &server_addr, argv[3], pid);return 0;}void recv_message(int server_fd){struct message msg;while (1){memset(&msg, 0, sizeof(msg));if (recvfrom(server_fd, &msg, sizeof(msg), 0, NULL, NULL) < 0){perror("failed to recv server message");exit(-1);}switch(msg.type){case CLIENT_LOGIN:login_msg(&msg);break;case CLIENT_CHA T:group_msg(&msg);break;case CLIENT_QUIT:quit_msg(&msg);break;case SERVER_CHA T:server_msg(&msg);break;case SERVER_QUIT:server_quit();break;default:break;}}return ;}void send_message(int server_fd, struct sockaddr_in *server_addr, char *name, pid_t pid) {struct message msg;char buf[512];msg.type = CLIENT_LOGIN;strcpy(, name);if (sendto(server_fd, &msg, sizeof(msg), 0,(struct sockaddr *)server_addr, sizeof(struct sockaddr)) < 0) {perror("failed to send login message");exit(-1);}while(1){memset(buf, 0, sizeof(buf));memset(&msg, 0, sizeof(msg));usleep(500);printf(">");fgets(buf, sizeof(buf), stdin);buf[strlen(buf) - 1] = 0;strcpy(msg.mtext, buf);strcpy(, name);msg.type = CLIENT_CHAT;if (strncmp(buf, "quit", 4) == 0){msg.type = CLIENT_QUIT;if (sendto(server_fd, &msg, sizeof(msg), 0,(struct sockaddr *)server_addr, sizeof(struct sockaddr)) < 0) {perror("failed to send quit message");exit(-1);}kill(pid, SIGKILL);waitpid(pid, NULL, 0);exit(0);}if (sendto(server_fd, &msg, sizeof(msg), 0,(struct sockaddr *)server_addr, sizeof(struct sockaddr)) < 0) {perror("failed to send group message");exit(-1);}}return ;}void login_msg(struct message *msg)printf("######## Login in ########\n");printf("%s is login in\n", msg->name);printf("######## Login in ########\n");return ;}void group_msg(struct message *msg){printf("******** Group Msg ********\n");printf("name: %s\n", msg->name);printf("msg: %s\n", msg->mtext);printf("******** Group Msg ********\n");return ;}void quit_msg(struct message *msg){printf("######## Quit Msg ########\n");printf("%s is Quit\n", msg->name);printf("######## Quit Msg ########\n");return ;}void server_msg(struct message *msg){printf("******** Server Msg ********\n");printf("msg: %s\n", msg->mtext);printf("******** Server Msg ********\n");return ;}void server_quit(void ){kill(getppid(), SIGKILL);exit(0);}。