<p style="text-align: left;">This article mainly introduces the relevant knowledge of how to implement the Linux chat room program. The editor shows you the operation process through actual cases. The operation method is simple, fast, and practical. I hope this article on how to implement the Linux chat room program can help Everyone solves the problem.</p><p style="text-align: left;"><strong>Code1:</strong></p><pre class="brush:bash; hljs cpp" deep="4" style="margin-top: 8px; margin-bottom: 8px; padding: 15px; box-sizing: border-box; overflow-x: auto; background-color: rgb(240, 242, 245); color: rgb(45, 48, 55); font-size: 14px; border: 1px solid rgb(219, 225, 232); border-radius: 4px; white-space: pre-wrap; overflow-wrap: break-word; word-break: break-all; text-align: left;">#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 = ' ';
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:%sn", chat_reader.time);
}
return(0);
}
#endif</pre><p><br/></p><p style="text-align: left;"><strong style="white-space: normal;">Code2:</strong></p><pre class="brush:bash; hljs cpp" style="margin-top: 8px; margin-bottom: 8px; padding: 15px; box-sizing: border-box; overflow-x: auto; background-color: rgb(240, 242, 245); color: rgb(45, 48, 55); font-size: 14px; border: 1px solid rgb(219, 225, 232); border-radius: 4px; white-space: pre-wrap; overflow-wrap: break-word; word-break: break-all; text-align: left;">#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: %sn", 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:%dn", 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 munun");
printf("t s--send messagen");
printf("t r--reply ton");
printf("t c--chat historyn");
printf("t f--send filesn");
printf("t e--exit the systemn");
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("nt%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 : %dn", log_msg.id_from);//printf("password: %sn", 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 successn");
return(0);
}
else {
printf("login error:%sn", 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) successn", 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 inputn");
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;
}
}</pre><p><br/></p>
