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, ' ', 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 usern");
printf("t c--chat historyn");
printf("t h--help menun");
printf("t e--exit the systemn");
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 errorn");
exit(1);
break;
case 0 :
msg_cntl();
break;
default :
menu();
break;
}
return(0);
}
