本文共 13540 字，大约阅读时间需要 45 分钟。
原文地址：
程序功能：
能够支持多个客户端同时运行，具有群聊，私聊，上线通知，下线通知，系统消息等功能。
程序如下：
１． server.c
#include2.client.c#include #include #include #include #include #include #include #include #define CLIENT_LOGIN 100#define CLIENT_CHAT 200#define CLIENT_QUIT 300#define SERVER_CHAT 400#define SERVER_QUIT 500#define PRINT_ONLINE 600#define PRIVATE_CHAT 700struct node { char name[20]; struct sockaddr_in client_addr; struct node *next;};struct message{ long type; char name[20]; char peer_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 print_online(int , struct node *, struct message *);void private_chat(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) { perror("failed to fork pid"); exit(-1); } if (pid == 0) recv_message(socket_fd, head); else send_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) { memset(&msg, 0, sizeof(msg)); 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_CHAT: client_chat(socket_fd, head, &msg); break; case CLIENT_QUIT: client_quit(socket_fd, head, &msg); break; case SERVER_CHAT: server_chat(socket_fd, head, &msg); break; case SERVER_QUIT: server_quit(socket_fd, head, &msg); break; case PRINT_ONLINE: print_online(socket_fd, head, &msg); break; case PRIVATE_CHAT: private_chat(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(msg.name , "server"); msg.type = SERVER_CHAT; 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); close(socket_fd); 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 print_online(int socket_fd, struct node *head, struct message *msg){ struct node *p = head->next; struct sockaddr_in my_addr; char buf[512]; printf("%s is request to print online client\n", msg->name); memset(buf, 0, sizeof(buf)); while (p != NULL) { if (strcmp(p->name, msg->name) == 0) my_addr = p->client_addr; strcat(buf, p->name); strcat(buf, " "); p = p->next; } strcpy(msg->mtext, buf); msg->type = PRINT_ONLINE; if (sendto(socket_fd, msg, sizeof(struct message), 0, (struct sockaddr *)&my_addr, sizeof(my_addr)) < 0) { perror("failed to send print_online message"); exit(-1); } return ;}void private_chat(int socket_fd, struct node *head, struct message *msg){ struct node *p = head->next; struct sockaddr_in peer_addr; printf("******** Private Msg ********\n"); printf("from %s\n", msg->name); printf("to %s\n", msg->peer_name); printf("msg: %s\n", msg->mtext); printf("*****************************\n"); while (p != NULL) { if (strcmp(p->name, msg->peer_name) == 0) { peer_addr = p->client_addr; break; } p = p->next; } if (sendto(socket_fd, msg, sizeof(struct message), 0, (struct sockaddr *)&peer_addr, sizeof(peer_addr)) < 0) { perror("failed to send private message"); exit(-1); } 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#include #include #include #include #include #include #include #include #define CLIENT_LOGIN 100#define CLIENT_CHAT 200#define CLIENT_QUIT 300#define SERVER_CHAT 400#define SERVER_QUIT 500#define PRINT_ONLINE 600#define PRIVATE_CHAT 700struct message{ long type; char name[20]; char peer_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);void online_msg(struct message *);void private_msg(struct message *);void print_online(int , struct message *, struct sockaddr_in *);void group_chat(int , struct message *, struct sockaddr_in *);void private_chat(int ,struct message *, struct sockaddr_in *);void client_quit(int , struct message *, struct sockaddr_in *, pid_t );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]);// inet_pton(AF_INET,argv[1],&server_addr.sin_addr); //ipv4 if ((pid = fork()) < 0) { perror("failed to fork pid"); exit(-1); } if (pid == 0) recv_message(server_fd); else send_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_CHAT: group_msg(&msg); break; case CLIENT_QUIT: quit_msg(&msg); break; case SERVER_CHAT: server_msg(&msg); break; case SERVER_QUIT: server_quit(); break; case PRINT_ONLINE: online_msg(&msg); break; case PRIVATE_CHAT: private_msg(&msg); 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]; int c; msg.type = CLIENT_LOGIN; strcpy(msg.name, 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) { usleep(500); printf("#####################################\n"); printf("the following options can be choose:\n"); printf("input 1 is to print online client\n"); printf("input 2 is to chat to all the client\n"); printf("input 3 is to chat to only one client\n"); printf("input q is to quit\n"); printf("#####################################\n"); printf(">"); c = getchar(); //输入回车符时停止输入到缓冲区 while (getchar() != '\n'); //读出全部缓冲区的数据，包括'\n' switch(c) { case '1': print_online(server_fd, &msg, server_addr); break; case '2': group_chat(server_fd, &msg, server_addr); break; case '3': private_chat(server_fd, &msg, server_addr); break; case 'q': client_quit(server_fd, &msg, server_addr, pid); break; default: break; } } 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);}void online_msg(struct message *msg){ printf("******** Online Client ********\n"); printf("%s\n", msg->mtext); printf("******** Online Client ********\n"); return ;}void private_msg(struct message *msg){ printf("******** Private Msg ********\n"); printf("name: %s\n", msg->name); printf("msg: %s\n", msg->mtext); printf("******** Private Msg ********\n"); return ;}void print_online(int server_fd, struct message *msg, struct sockaddr_in *server_addr){ msg->type = PRINT_ONLINE; if (sendto(server_fd, msg, sizeof(struct message), 0, (struct sockaddr *)server_addr, sizeof(struct sockaddr)) < 0) { perror("failed to send online message"); exit(-1); } return ;}void group_chat(int server_fd, struct message *msg, struct sockaddr_in *server_addr){ char buf[512]; memset(buf, 0, sizeof(buf)); printf("*********** Group Chat Room ***********\n"); printf("****** Welcome to group chat room ******\n"); printf("* if you want to quit, please input quit\n"); printf("****************************************\n"); while(1) { memset(buf, 0, sizeof(buf)); usleep(500); printf(">"); fgets(buf, sizeof(buf), stdin); buf[strlen(buf) - 1] = 0; msg->type = CLIENT_CHAT; strcpy(msg->mtext, buf); if (strncmp(buf, "quit", 4) == 0) break; if (sendto(server_fd, msg, sizeof(struct message), 0, (struct sockaddr *)server_addr, sizeof(struct sockaddr)) < 0) { perror("failed to send group message"); exit(-1); } } return ;}void private_chat(int server_fd, struct message *msg, struct sockaddr_in *server_addr){ char name[20]; char buf[512]; memset(name, 0, sizeof(name)); printf("please input the peer_name\n"); printf(">"); fgets(name, sizeof(name), stdin); name[strlen(name) - 1] = 0; strcpy(msg->peer_name, name); msg->type = PRIVATE_CHAT; printf("connect to %s OK!\n", msg->peer_name); while(1) { usleep(500); printf(">"); fgets(buf, sizeof(buf), stdin); buf[strlen(buf) - 1] = 0; strcpy(msg->mtext, buf); if (strncmp(buf, "quit", 4) == 0) break; if (sendto(server_fd, msg, sizeof(struct message), 0, (struct sockaddr *)server_addr, sizeof(struct sockaddr)) < 0) { perror("failed to send private message"); exit(-1); } } return ;}void client_quit(int server_fd, struct message *msg, struct sockaddr_in *server_addr, pid_t pid){ msg->type = CLIENT_QUIT; if (sendto(server_fd, msg, sizeof(struct message), 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);}
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