linux上的一个简单的多人聊天室

 花了很长时间用来联系掌握linux 上socket的一个聊天室程序,可以
/*
 *i.h is a used for creating a library
 *for server client
 *Mar 18 2010	
 *
 */
#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
/*
 *title:server.c
 *content:server part
 *start time: Mar.25.2011
 *end time:  Apr.8 2011
 */

#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);
}
/*
 *title: client.c
 *start_time: Mar.18 2011
 *end_time:  Apr.8 2011
 */

#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(&reg_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(&reg_msg); /* save to history */

	/* send regist informatin to server */
	i_sendto(sockfd, (struct msg*)&reg_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;
	}
}

编程技巧