花了很长时间用来练习掌握linux上socket的一个聊天室程序，可以实现的哦。
具体代码如下
代码一：
#ifndef _I_H #define _I_H #include <math.h>#include <stdio.h>#include <sys/socket.h>#include <arpa/inet.h>#include <netinet/in.h>#include <unistd.h>#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <stdlib.h>#include <errno.h>#include <string.h>#include <inttypes.h>#include <time.h>#include <sys/ioctl.h> #include <net/if.h>#include <signal.h>#include <ncurses.h>#include <math.h> #define SEVR_IP "127.0.0.1"#define SEVR_PORT 8081#define CNTNT_LEN 150#define MSG_LEN sizeof(struct msg)#define ADDR_LEN sizeof(struct sockaddr)#define USR_LEN sizeof(struct user)#define PRT_LEN 8#define HSTR_LEN sizeof(struct chat_history) /* declare Global variables */int mainfd;/* used as chat histroy file handle*/int sockfd;/* used as socket local handle */int count;struct sockaddr_in server; /* msg is used for communicating message */struct msg{ int flag; /* flag meaning:1,ordinary; 2,log msg; 3,reg msg, other,file*/ int id_from; int id_to; char content[CNTNT_LEN]; char append[10]; }; /* user is used information list */struct user{ int id; char name[10]; char password[10]; char *p_chatlog; struct sockaddr user_addr; };/* chat_history used for reading chat history */struct chat_history{ char content[CNTNT_LEN]; char time[25]; int to; int from; int count;}; /* i_functions below is funtions needed by both client and sever */extern int i_saveto_chat(struct msg *pmsg); int i_clean_stdin (){ while ('/n' == getchar()) { continue; } return(0);} int i_print(char *pmsg, int size){ int i = 1; for (i; i<= size; i++) { if (*pmsg != '/n') { printf("%c", *pmsg); pmsg ++; } else { return(0); } } return(0);}int i_input(char *p_input){ char c = '/0'; int i; for (i = 0; i < CNTNT_LEN; i++) { p_input[i] = getchar(); if (p_input[i] =='/n') { return(0); } } printf("you have input long enough!/n"); return(0);}int i_socket(int domain, int type, int protocol){ int fd; if ((fd = socket(domain, type, protocol)) == -1) { perror("creat socket error:"); exit(1); } return(fd); } int i_bind(int fd, const struct sockaddr *addr, int namelen){ if (-1 == bind(fd, addr, namelen)) { perror("i_bind error:"); exit(1); } return (0);} int i_recvfrom(int fd, void *buf, size_t len, int flags, struct sockaddr *addr, int *size){ if (-1 == recvfrom(fd, buf, len, flags, addr, size)) { perror("i_recvfrom error:"); exit(1); } return(0);} int i_sendto(int fd, void *buf, size_t len, int flags, struct sockaddr *addr, int size){ if (-1 == sendto(fd, buf, len, flags, addr, size)) { perror("i_sendto error"); exit(1); } return (0);} int i_open(const char *pathname, int flags){ int fd; if ((fd = open(pathname, flags)) == -1) { perror("open_failed"); exit(1); } return (fd);}int i_read(int fd, void *msg, int len){ if(-1 == read(fd, msg, len)) { perror("i_read error"); exit(1); } return(0);}int i_write(int fd, void *msg, int len){ if (-1 == write(fd, msg, len)) { perror("i_write error"); exit(0); } return(0);} /* init a socket,file and server addr */int i_init(){ mainfd = i_open("./chat_log", O_RDWR|O_CREAT); sockfd = i_socket(AF_INET, SOCK_DGRAM, 0); /* initialize server address */ bzero(&server, sizeof(server)); server.sin_family = AF_INET; inet_pton(AF_INET, "127.0.0.1", &server.sin_addr); server.sin_port = htons(SEVR_PORT); perror("init"); return (0);} char *i_get_time(){ time_t time_now; time(&time_now); return(ctime(&time_now));}int i_lseek(int fd, off_t size, int position){ if (-1 == lseek(fd, size, position)) { perror("seek error"); exit(1); } return(0);}int i_saveto_chat(struct msg *pmsg){ struct chat_history hstr; bzero(&hstr, HSTR_LEN); count = count + 1; hstr.count =count; hstr.from = pmsg->id_from; hstr.to = pmsg->id_to; strncpy(hstr.content, pmsg->content, CNTNT_LEN); strncpy(hstr.time, i_get_time(), 25); i_lseek(mainfd, 0, SEEK_END); i_write(mainfd, &hstr, HSTR_LEN); return(0);} int i_print_history(int len, int i){ struct chat_history chat_reader; int j; int position; bzero(&chat_reader, HSTR_LEN); if (i != 0) { position = len*i*HSTR_LEN; i_lseek(mainfd, position, SEEK_END); } else { position = len*i*HSTR_LEN; i_lseek(mainfd, HSTR_LEN, SEEK_SET); } for (j = 1; j <= len; j++) { i_read(mainfd, &chat_reader, HSTR_LEN); printf("/n#item%d:id%dto id%d /n", j, chat_reader.from, chat_reader.to); i_print(chat_reader.content, CNTNT_LEN); printf("/n Time:%s/n", chat_reader.time); } return(0);} #endif 代码二：
#include "i.h" int user_list_fd; /* start:initialization */int init(){ i_init(); user_list_fd = i_open("./user_list", O_RDWR|O_CREAT); struct user usr; /* init the user list file's fist user to 0*/ memset((struct user*)&usr, '/0', sizeof(struct user)); i_lseek(user_list_fd, 0, SEEK_SET); i_write(user_list_fd, (char*)&usr, USR_LEN); /* bind the struct sockaddr_in server to the sockfd */ i_bind(sockfd, (struct sockaddr*)&server, ADDR_LEN); struct chat_history apple; bzero(&apple, HSTR_LEN); i_lseek(mainfd, 0, SEEK_SET); i_write(mainfd, &apple, HSTR_LEN); i_lseek(mainfd, -HSTR_LEN, SEEK_END); i_read(mainfd, &apple, HSTR_LEN); count = apple.count; return(0);}/* end:initialization */ /* start:message control */int send_msg(struct msg *msg_recv, struct sockaddr *addr){ int i; struct user usr; /* a common message come */ printf("a ordinar message come !/n"); i = msg_recv->id_to; i_lseek(user_list_fd, i*USR_LEN, SEEK_SET); i_read(user_list_fd, &usr, USR_LEN); strncpy(msg_recv->append, usr.name, 10); i_sendto(sockfd, msg_recv, MSG_LEN, 0, &(usr.user_addr), ADDR_LEN); printf("id%d send a message to id%d sucess!/n", msg_recv->id_from, msg_recv->id_to); return(0);}int check_login(struct msg *msg_recv, struct sockaddr *addr){ int i = msg_recv->id_from;; struct user usr; /* a login requet */ printf("a login request come!/n"); /* get the id's information */ i_lseek(user_list_fd, i*USR_LEN, SEEK_SET); i_read(user_list_fd, &usr, USR_LEN); int n; n = strcmp(usr.password, msg_recv->content); /* 如果验证成功，则发送成功信息 */ if (n == 0) { /* save user new address */ i_lseek(user_list_fd, -USR_LEN, SEEK_CUR); usr.user_addr = *addr; i_write(user_list_fd, &usr, USR_LEN); /* tell user pass */ i_sendto(sockfd, (struct msg*)msg_recv, sizeof(struct msg), 0, &(usr.user_addr), ADDR_LEN); } else { /* 出错的话的respond */ if (0 != n) { printf("id %d login error./n", i); bzero(msg_recv->content, CNTNT_LEN); msg_recv->flag = -1; i_sendto(sockfd, (struct msg*)msg_recv, sizeof(struct msg), 0, &(usr.user_addr), ADDR_LEN); } return(1); } printf("Id %d login sucess!/n", i); return(0);}int reg_user(struct msg *msg_recv, struct sockaddr *addr){ struct user usr; printf("a regit requet come:/n"); /* find the last user and hava the please to add a new user */ int n; i_lseek(user_list_fd, -USR_LEN, SEEK_END); i_read(user_list_fd, &usr, USR_LEN); /* 把新用户的信息赋值到usr然后填入到user list file中 */ const char *name; const char *password; name = &(msg_recv->content[0]); password = &(msg_recv->content[10]); strcpy((usr.name), name); strcpy(usr.password, password); memcpy(&(usr.user_addr),addr, ADDR_LEN); usr.id = (usr.id + 1); i_lseek(user_list_fd, 0, SEEK_END); i_write(user_list_fd, &usr, USR_LEN); msg_recv->id_from = usr.id; /* regist to the user list then tell the user reg success */ i_sendto(sockfd, (struct msg*)msg_recv, sizeof(struct msg), 0, addr, ADDR_LEN); printf("Id %d regist sucess!/n", usr.id); return(0); }int msg_cntl(){ struct msg msg_recv; struct sockaddr addr_recv; printf("begin listen input.../n"); int size = ADDR_LEN; for (;;) { bzero(&msg_recv, MSG_LEN); i_recvfrom(sockfd, &msg_recv, sizeof(struct msg), 0, &addr_recv, &size); printf("message received.../n"); i_saveto_chat(&msg_recv); switch (msg_recv.flag) { case 1 : send_msg(&msg_recv,(struct sockaddr*)&addr_recv);/* send ordinary chat */ break; case 2 : check_login(&msg_recv, (struct sockaddr*)&addr_recv); break; case 3 : reg_user(&msg_recv, (struct sockaddr*)&addr_recv); break; default : break; } } return(0);}/* end:message control*//* start:exit_sys()*/int exit_sys(){ close(sockfd); close(mainfd); close(user_list_fd); printf("exit system"); kill(0, SIGABRT); exit(0);}/* end:exit_sys()*/ /* start:chat_history*/int get_page_size(){ struct chat_history page_size_reader; i_lseek(mainfd, -HSTR_LEN, SEEK_END); i_read(mainfd, &page_size_reader, HSTR_LEN); return(page_size_reader.count);} int read_chat_history(){ printf("****char*history***"); printf("(n-nextpage; p-prepage; q-quit)/n"); int page_num;/* */ int remains; int berry = get_page_size(); page_num = berry / 8; remains = berry % 8; if (remains != 0) page_num ++; else page_num = page_num; printf("there are %d page total %d items", page_num, berry); int i = -1; while (1) { char flag; if ((berry + i*8) >= 0) { printf("(%d~%d)/n", (berry + i*8), (berry + (i+1)*8)); i_print_history(PRT_LEN, i); printf("@@@/n"); while ('/n' == (flag = getchar())) { } switch (flag) { case 'p' : i--; break; case 'n' : i++; break; case 'q' : return(0); default : break; } if (i >= 0) { printf("have at the end!/n"); printf("return to menu!/n"); } } else { printf("(1~%d)/n", remains); i_print_history(remains, 0); printf("#########over##############/n"); return(0); } } return(0);}/* end:chat_history*//* start:menu*/int menu(){ sleep(1); printf("----------help----menu---------/n"); printf("/t r--report to user/n"); printf("/t c--chat history/n"); printf("/t h--help menu/n"); printf("/t e--exit the system/n"); printf("----------help_menu---------/n"); int command = 0; printf("input command>"); command = getchar(); switch(command) { case 'c': read_chat_history(); break; case 'e': exit_sys(); break; case 'r': //report(); //break; default : menu(); break; } getchar(); return(0);}/* end:menu*/int main(){ init(); pid_t pid; switch (pid = fork()) { case -1 : perror("fork error/n"); exit(1); break; case 0 : msg_cntl(); break; default : menu(); break; } return(0);} 代码三：
#include "i.h" #define START_PORT 8089 struct sockaddr_in my_addr;int my_id; int my_log();/* declare funtion*/ /* */int i_send_msg(){ int id; struct msg the_msg; char end = '@'; printf("input recver id:"); scanf("%d", &id); getchar(); printf("/ninput content:"); i_input(the_msg.content); char flag = 'y'; if (1) { the_msg.flag = 1; the_msg.id_from = my_id; the_msg.id_to = id; i_sendto(sockfd, &the_msg, sizeof(struct msg), 0, (struct sockaddr*)&server, sizeof(struct sockaddr)); i_saveto_chat(&the_msg); /* save to history */ printf("send to id:%d success./n", my_id); return(0); } else return(1); return(0);} int reply(){ return(0);}int send_file(){ return(0);}/**//* start:initialize */int init(){ struct ifreq req; struct sockaddr_in *host; int port; i_init(); /* init user addr */ bzero(&my_addr, sizeof(struct sockaddr)); my_addr.sin_family = AF_INET; strcpy(req.ifr_name, "lo"); if ( ioctl(sockfd, SIOCGIFADDR, &req) < 0 ) /* get local ip address */ { perror("get local ip error"); exit(1); } host = (struct sockaddr_in*)&(req.ifr_addr); printf("ip: %s/n", inet_ntoa(host->sin_addr)); memcpy(&my_addr, (struct sockaddr_in*)&(req.ifr_addr), sizeof(struct sockaddr_in)); port = START_PORT; do { port++; my_addr.sin_port = htons(port); bind(sockfd, (struct sockaddr*)&my_addr, sizeof(struct sockaddr)); } while (errno == EADDRINUSE); struct chat_history apple; memset(&apple, 'b', HSTR_LEN); i_lseek(mainfd, 0, SEEK_SET); apple.count = 0; i_write(mainfd, &apple, HSTR_LEN); i_lseek(mainfd, -HSTR_LEN, SEEK_END); i_read(mainfd, &apple, HSTR_LEN); count = apple.count; printf("port:%d/n", port); printf("init successful!!!/n"); return(0); }/* end:initialize *//* start:chat_history*/int get_page_size(){ struct chat_history page_size_reader; i_lseek(mainfd, -HSTR_LEN, SEEK_END); i_read(mainfd, &page_size_reader, HSTR_LEN); return(page_size_reader.count);} int read_chat_history(){ printf("****char*history***"); printf("(n-nextpage; p-prepage; q-quit)/n"); int page_num;/* */ int remains; int berry = get_page_size(); page_num = berry / 8; remains = berry % 8; if (remains != 0) page_num ++; else page_num = page_num; printf("there are %d page total %d items", page_num, berry); int i = -1; while (1) { char flag; if ((berry + i*8) >= 0) { printf("(%d~%d)/n", (berry + i*8), (berry + (i+1)*8)); i_print_history(PRT_LEN, i); printf("@@@/n"); while ('/n' == (flag = getchar())) { } switch (flag) { case 'p' : i--; break; case 'n' : i++; break; case 'q' : return(0); default : break; } if (i >= 0) { printf("have at the end!/n"); printf("return to menu!/n"); } } else { printf("(1~%d)/n", remains); i_print_history(remains, 0); printf("#########over##############/n"); return(0); } } return(0);}/* end:chat_history*//* start:exit_sys*/void exit_sys(){ close(sockfd); close(mainfd); kill(0, SIGABRT); exit(0);}/* end:exit_sys*/ /* start:menu*/int print_menu(){ printf("/n--------------help--menu----------------/n"); printf("/t h--help munu/n"); printf("/t s--send message/n"); printf("/t r--reply to/n"); printf("/t c--chat history/n"); printf("/t f--send files/n"); printf("/t e--exit the system/n"); printf("----------------help--menu----------------/n");}int get_input(char *command){ printf(">"); scanf("%c", command); return(1);}int menu(){ /* to avoid the output at mixed with the sub process */ sleep(1); print_menu(); char command; while (1 == get_input(&command)) { switch(command) { case 'h': print_menu(); break; case 's': i_send_msg(); break; case 'r': reply(); break; case 'f': send_file(); break; case 'c': read_chat_history(); break; case 'e': exit_sys(); break; default : printf(">"); break; } } return(0);}/* end:menu*//* start:message contol :send_msg and recv_msg */int ordnary_msg_recv(struct msg *pmsg){ char time_info[25]; char end_symble; end_symble = '&'; /* handle the msg */ printf("Message:from %s(id%d) to U:/n", pmsg->append, pmsg->id_from); i_print(pmsg->content, MSG_LEN); printf("/n/t%s", i_get_time()); return(0);}int file_msg_recv(struct msg *pmsg){}int handle_msg(struct msg *pmsg){ if (pmsg->flag == 1) { ordnary_msg_recv(pmsg); return(0); } else if (pmsg->flag >= 4) { file_msg_recv(pmsg); return(0); } return(0);}int listen_msg(){ struct msg msg_recv; struct sockaddr addr_recv; int len = ADDR_LEN; printf("begin listen.../n"); for ( ; ; ) { i_recvfrom(sockfd, &msg_recv, MSG_LEN, 0, &addr_recv, &len); i_saveto_chat(&msg_recv); /* save to history */ ordnary_msg_recv(&msg_recv); }} /* end:message contol*/ /* start:log process :login and regist */int login(){ /* input id:*/ printf("*****login>>/n"); printf("id:"); scanf("%d", &my_id); /* input password*/ char password[15]; printf("/npassword(*less 15 char):"); scanf("%s", password); getchar(); /* send login information */ struct msg log_msg; bzero(&log_msg, MSG_LEN); log_msg.flag = 2; log_msg.id_from = my_id; log_msg.id_to = 0; strncpy(log_msg.content, password, 15); i_saveto_chat(&log_msg); /* save to history */ i_sendto(sockfd, (struct msg*)&log_msg, MSG_LEN, 0, (struct sockaddr*)&server, sizeof(struct sockaddr));//printf("log_msg : %d/n", log_msg.id_from);//printf("password: %s/n", log_msg.content); /* after input msg ,wait for server respond*/ struct sockaddr in_addr; int len = ADDR_LEN; i_recvfrom(sockfd, (struct msg*)&log_msg, MSG_LEN,0, &in_addr, &len); if (2 == log_msg.flag) { printf("login success/n"); return(0); } else { printf("login error:%s/n", log_msg.content); printf("please relog../n"); menu(); } return (0);}int regist(){ printf("*****regist>>/n"); /* input chat name */ char name[10]; bzero(name, 10); printf("input your chat name(less 8 char):"); scanf("%s", name); //name[9] = ';'; /* add a ; symbol in the end of name */ /* input password */ char password[15]; bzero(password, 15); printf("/ninput your password(less 14 char):"); scanf("%s", password); /* send regist information*/ struct msg reg_msg; bzero(®_msg, MSG_LEN); reg_msg.flag = 3; reg_msg.id_from = 0; reg_msg.id_to = 0; bzero(reg_msg.content, CNTNT_LEN); strncpy(reg_msg.content, name, 10); strncpy(&(reg_msg.content[10]), password, 15); reg_msg.content[25] = '/n'; i_saveto_chat(®_msg); /* save to history */ /* send regist informatin to server */ i_sendto(sockfd, (struct msg*)®_msg, sizeof(struct msg), 0, (struct sockaddr*)&server, ADDR_LEN); /* after input msg ,wait for server respond*/ printf("wating for server reply.../n"); struct sockaddr in_addr; struct msg msg_back; int len = ADDR_LEN; bzero(&in_addr, ADDR_LEN); bzero(&msg_back, MSG_LEN); i_recvfrom(sockfd,(struct msg*)&msg_back, MSG_LEN,0, &in_addr, &len); /* check whether pass */ if (3 != msg_back.flag) { printf("error: %s /n", msg_back.content); exit(1); } else my_id = msg_back.id_to; printf("congratulate! you have regist" "id %s(id %d) success/n", msg_back.content, msg_back.id_to); login(); return(0); } int my_log(){ /* choose login or regist*/ char flag; printf("are you want login or regist(l/r)/n"); scanf("%c", &flag); getchar(); switch (flag){ case 'l' : login(); break; case 'r' : regist(); break; default : printf("error input/n"); my_log(); break; } return (0);}/* end:log */ int main(){ init(); printf("/n************welcome!************/n"); my_log(); pid_t pid; switch (pid = fork()) { case -1 : perror("fork error!/n"); exit(1); break; case 0 : listen_msg(); break; default : menu(); break; }} 希望本文所述对大家实现linux多人聊天室程序。
