#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <unistd.h>
#include <pthread.h>
void* recv_msg(void* arg);
int is_my_ip(const char* ip); //判断是否是本机IP地址,如果是返回1,否则返回0
/*
char* inet_ntoa_dj()
{
static char ip[20];
static int i=0;
i++;
sprintf(ip,"128.0.34.%d",i);
return ip;
}
*/
int main()
{
/*
char* p1=inet_ntoa_dj();
printf("%s\n",p1);
char ip[20];
strcpy(ip,p1);
char* p2=inet_ntoa_dj();
printf("%s\n",p1);
printf("%s\n",p2);
exit(0);
*/
int sock=socket(AF_INET,SOCK_DGRAM,0);
int optval=1;
setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,&optval,sizeof(optval));
setsockopt(sock,SOL_SOCKET,SO_BROADCAST,&optval,sizeof(optval));
//被动通信方必须显式绑定
struct sockaddr_in myaddr;
myaddr.sin_family=AF_INET;
myaddr.sin_addr.s_addr=INADDR_ANY;
myaddr.sin_port=htons(8888);
if(-1==bind(sock,(struct sockaddr*)&myaddr,sizeof(myaddr)))
{
perror("bind");
exit(1);
}
pthread_t tid;
pthread_create(&tid,NULL,recv_msg,(void*)sock);
char msg[1024];
struct sockaddr_in addr;
addr.sin_family=AF_INET;
addr.sin_addr.s_addr=inet_addr("128.0.255.255");
addr.sin_port=htons(8888);
while(1)
{
printf("\n我说:");
fgets(msg,sizeof(msg),stdin);
sendto(sock,msg,strlen(msg),0,(struct sockaddr*)&addr,sizeof(addr));
}
close(sock);
return 0;
}
void* recv_msg(void* arg)
{
int sock=(int)arg;
char msg[1024];
int ret;
struct sockaddr_in addr;
socklen_t addrlen=sizeof(addr);
while(1)
{
ret=recvfrom(sock,msg,sizeof(msg)-1,0,(struct sockaddr*)&addr,&addrlen);
if(ret>0)
{
if(is_my_ip(inet_ntoa(addr.sin_addr))) continue;
msg[ret]='\0';
printf("%s:%d说:%s\n",inet_ntoa(addr.sin_addr),ntohs(addr.sin_port),msg);
}
}
return NULL;
}
int is_my_ip(const char* ip_des) //判断是否是本机IP地址,如果是返回1,否则返回0
{
char ip[20];
strcpy(ip,ip_des);
//获取主机名
char host_name[100];
gethostname(host_name,sizeof(host_name));
//printf("主机名:%s\n",host_name);
//获取本机所有IP地址
struct hostent *he=gethostbyname(host_name);
char* ip_tmp=NULL;
if(he!=NULL)
{
int i=0;
//printf("本机IP地址如下:\n");
while(he->h_addr_list[i]!=NULL)
{
//printf("%s\n",inet_ntoa(*(struct in_addr*)(he->h_addr_list[i])));
ip_tmp=inet_ntoa(*(struct in_addr*)(he->h_addr_list[i]));
if(strcmp(ip_tmp,ip)==0)
{
return 1;
}
i++;
}
}
return 0;
}
解决办法:ubuntu系统中缺少一个套件 ncurses devel ,把此套件安装下即可
$ sudo apt-get install libncurses5-dev
/*
功能: 在同一台服务器上ssh登录的用户可以群聊(聊天室)
原理: 1、通过roomNo.来区分不同的房间或群组;
2、以roomNo.作为key来创建一块共享内存,来保存进入到该room的用户列表;
3、用户以ssh(或其它方式)登录到服务器,在/dev/pts/目录下都会有一个对应文件;
4、自己的用户名和对应的设备文件名可从环境变量(USER和SSH_TTY)中获取到;
5、通过向用户对应的设备名中写数据,用户就可以收到;
6、用户在发送信息时向用户列表中的用户逐个发送,即可实现群聊功能;
实际上是对“write”命令的加强而已。
遇到的问题:
1、显示不显示汉字受终端软件影响,自己配置下;
2、获取自己用户名和对应的设备文件名,寻找了很多方式,最终发现通过环境变量最简单;
3、没有权限open方式其他用户对应的设备,通过修改/dev/pts/下的文件权限为622解决,
最好自己根目录的.bashrc脚本文件中加入“chmod 622 $SSH_TTY”,这样每次登录时会自动修
改;暂没找到其它更好方法;
4、fgets方式获取的字符串不能backspace,网上朋友说修改VERASE值为0x08,试验发现可以,
但删汉字时,一个汉字要对应2个backspace;
5、在自己输入信息到一半,但还没有回车发送便收到其它用户的信息时,自己输入的信息
被打断,再解决这个问题就更接近完美了;
*/
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <utmp.h>
#include <pwd.h>
#include <sys/types.h>
#include <sys/shm.h>
#include <signal.h>
#include <stdbool.h>
#include <termios.h>
#include <curses.h>
#ifndef _SHMDATA_H_HEADER
#define _SHMDATA_H_HEADER
//同时在线的用户最大数量,可更改
#define USER_NUM 20
#define USER_LEN 30
struct shared_users_st
{
int written; //作为一个标志,非0:表示不可写,0表示可读写
char users[USER_NUM][USER_LEN]; //记录写入和读取的文本, zhi.wang@/dev/pts/2
};
#endif
void utmpinfo();
void pwentinfo();
char *getuser();
char *gettty();
void msgparser(char *buffer);
int shmcreate(key_t key);
int shmdetach(void *shm);
int shmdestroy(int shmid);
int shmuseradd(struct shared_users_st *);
int shmuserclear(struct shared_users_st *);
int shmuserexit(struct shared_users_st *);
int shmuserlist(struct shared_users_st *);
int shmusermsg(struct shared_users_st *, char *);
bool userinutmp(char *);
void *shm = NULL;
int shmid;
int mylocal = -1; //记录自己在shm中的位置,退出时方便删除
struct termios new; /* 控制终端状态的数据结构,可 man termios 查看*/
struct termios old;
//全局开关
//匿名发送消息
bool ishidden = false;
bool running = true;
char prompt = '_';
static char *help = "\
:l List users;\n\
:c Clear all users;\n\
:q Quit;\n\
:help Help;\n\
:hide set anonymous;\n\
:nohide set noanonymous;\n\
";
void sig_handler( int sig);
void chatroominit();
void chatroomquit();
void chatroominit()
{
signal(SIGINT, sig_handler);
tcgetattr(0,&old); /* 得到当前的终端状态 */
new = old;
//printf("old[VERASE]=0x%x\n\n", old.c_cc[VERASE]);
new.c_cc[VERASE] = 0x08; //实现backspace功能
tcsetattr(0,TCSANOW,&new); /* 应用新的设置*/
}
void chatroomquit()
{
tcsetattr(0,TCSANOW,&old);
//shmuserclear(shm);
shmuserexit((struct shared_users_st *)shm);
//shmdetach(shm);
}
//处理ctrl+c
void sig_handler( int sig)
{
//printf("%s %d \n", __FUNCTION__, sig);
if(sig == SIGINT )
{
chatroomquit();
exit(0);
}
}
int main()
{
char buffer[BUFSIZ + 1];//用于保存输入的文本
char *roomno;
//printf(" ** room NO.: %d\n", sizeof(struct shared_users_st));
roomno = getpass("Please enter room No.:");
//printf(" ** room NO. is : %s\n", roomno);
chatroominit();
//setuid(0);
shmid = shmcreate((key_t)atoi(roomno));
shmuseradd((struct shared_users_st *)shm);
shmuserlist((struct shared_users_st *)shm);
while (running)
{
printf("%c", prompt);
memset(buffer, 0, BUFSIZ + 1);
fgets(buffer, BUFSIZ, stdin);
msgparser(buffer);
}
chatroomquit();
exit(EXIT_SUCCESS);
}
//分析输入内容
void msgparser(char *buffer)
{
char c;
switch (c = buffer[0])
{
case ':':
if (strncmp(buffer+1, "q", 1) == 0)
{
running = false;
//检查是否还有在线用户,如没有则销毁
}
else if (strncmp(buffer+1, "help", 4) == 0)
{
printf("%s\n", help);
}
else if (strncmp(buffer+1, "clear", 5) == 0)
{
shmuserclear((struct shared_users_st *)shm);
}
else if (strncmp(buffer+1, "l", 1) == 0)
{
shmuserlist((struct shared_users_st *)shm);
}
else if (strncmp(buffer+1, "hide", 4) == 0)
{
ishidden = true;
}
else if (strncmp(buffer+1, "nohide", 6) == 0)
{
ishidden = false;
}
break;
case '?':
printf("%s\n", help);
break;
default:
//printf("%d %d\n", strlen(buffer), buffer[0]);
//空格和换行不发送
if ((strlen(buffer) <= 2 && buffer[0] == 32) ||
(strlen(buffer) <= 1 && buffer[0] == 10))
{
break;
}
//printf("%s\n", buffer);
shmusermsg((struct shared_users_st *)shm, buffer);
}
}
char *getuser()
{
return getenv("USER");
}
char *gettty()
{
return getenv("SSH_TTY");
}
static void waitwrite(struct shared_users_st *shared)
{
//数据还没有被读取,则等待数据被读取,不能向共享内存中写入文本
//shared->written = 0;
while(shared->written == 1)
{
sleep(1);
printf("Waiting...\n");
}
}
int shmcreate(key_t key)
{
char buffer[BUFSIZ + 1];//用于保存输入的文本
//创建共享内存
shmid = shmget((key_t)key, sizeof(struct shared_users_st), 0666|IPC_CREAT);
if(shmid == -1)
{
fprintf(stderr, "shmget failed\n");
//exit(EXIT_FAILURE);
}
//将共享内存连接到当前进程的地址空间
shm = shmat(shmid, (void*)0, 0);
if(shm == (void*)-1)
{
fprintf(stderr, "shmat failed\n");
//exit(EXIT_FAILURE);
}
//printf("Memory attached at %X\n", (int)shm);
return shmid;
}
int shmdetach(void *shm)
{
//把共享内存从当前进程中分离
if(shmdt(shm) == -1)
{
fprintf(stderr, "shmdt failed\n");
exit(EXIT_FAILURE);
}
return 0;
}
int shmdestroy(int shmid)
{
//printf(" ** %s\n", __FUNCTION__);
//删除共享内存 SHM_DEST
if(shmctl(shmid, IPC_RMID, 0) == -1)
{
fprintf(stderr, "shmctl(IPC_RMID) failed(%d).\n", shmid);
exit(EXIT_FAILURE);
}
return 0;
}
int shmuseradd(struct shared_users_st *shared)
{
//struct shared_users_st *shared = NULL;
char buffer[BUFSIZ + 1];//用于保存输入的文本
int i = 0;
char *p = NULL;
//设置共享内存
//shared = (struct shared_users_st*)shm;
//向共享内存中写入数据
strcat(buffer, getuser());
strcat(buffer, "@");
strcat(buffer, gettty());
//printf("buffer:%s\n", buffer);
waitwrite(shared);
//向共享内存中写入数据前先置1,其它进程不可写
shared->written = 1;
do
{
//没有找到@时,或者找到自己对应的tty时则替换
if ((p = strchr(shared->users[i],'@')) == 0)
{
if (mylocal == -1)
{
//printf("%s %s %d\n", __FUNCTION__, buffer, i);
strncpy(shared->users[i], buffer, USER_LEN);
//记录下自己所在位置,退出时自己删除
mylocal = i;
}
else
{
//printf("%s %s %d reset.\n", __FUNCTION__, shared->users[i], i);
memset(shared->users[i], 0, USER_LEN);
}
}
else
{
//printf("\n\nbuffer: %s != %s %d=%d\n\n", p+1, gettty(), strlen(p+1) ,strlen(gettty()));
if (!strncasecmp(p+1, gettty(), strlen(p+1) > strlen(gettty()) ? strlen(p+1) : strlen(gettty()) ))
{
if (mylocal == -1)
{
//printf("%s %s %d\n", __FUNCTION__, buffer, i);
strncpy(shared->users[i], buffer, USER_LEN);
//记录下自己所在位置,退出时自己删除
mylocal = i;
}
else
{
//printf("%s %s %d reset.\n", __FUNCTION__, shared->users[i], i);
memset(shared->users[i], 0, USER_LEN);
}
}
//continue;
//检查user和tty跟当前系统登录的是否匹配(参考w命令)
if (userinutmp(shared->users[i]) == false)
{
printf(" ## %s %s %d autodelete.\n", __FUNCTION__, shared->users[i], i);
memset(shared->users[i], 0, USER_LEN);
}
}
//memset(shared->users[i], 0, USER_LEN);
} while (++i < USER_NUM);
//写完数据,设置written使共享内存段可读
shared->written = 0;
if (mylocal != -1)
{
//告诉在线用户,我已加入
memset(buffer, 0, BUFSIZ + 1);
sprintf(buffer, "\n ## Welcome %s to our room.\n", shared->users[mylocal]);
shmusermsg(shared, buffer);
}
return 0;
}
//清空所有用户
int shmuserclear(struct shared_users_st *shared)
{
//struct shared_users_st *shared = NULL;
int i = 0;
char buffer[BUFSIZ + 1];//用于保存输入的文本
//设置共享内存
//shared = (struct shared_users_st*)shm;
//数据还没有被读取,则等待数据被读取,不能向共享内存中写入文本
waitwrite(shared);
//向共享内存中写入数据前先置1,其它进程不可写
shared->written = 1;
do
{
//找到@时
if (rindex(shared->users[i],'@') != 0)
{
memset(buffer, 0, BUFSIZ + 1);
sprintf(buffer, "\n ## %s has been kicked out of the room.\n\n\n",
shared->users[i]);
shmusermsg(shared, buffer);
memset(shared->users[i], 0, USER_LEN);
//break;
}
} while (++i < USER_NUM);
//写完数据,设置written使共享内存段可读
shared->written = 0;
return 0;
}
//退出时只删除自己即mylocal所标记位置
//如果退出时没有在线用户,则销毁shm
int shmuserexit(struct shared_users_st *shared)
{
//struct shared_users_st *shared = NULL;
char buffer[BUFSIZ + 1];//用于保存输入的文本
int i = 0;
//设置共享内存
//shared = (struct shared_users_st*)shm;
//printf("%s %s %d\n", __FUNCTION__, shared->users[mylocal], mylocal);
//告诉在线用户,我已离开
memset(buffer, 0, BUFSIZ + 1);
sprintf(buffer, "\n ## %s exit the room.\n", shared->users[mylocal]);
shmusermsg(shared, buffer);
//数据还没有被读取,则等待数据被读取,不能向共享内存中写入文本
waitwrite(shared);
//向共享内存中写入数据前先置1,其它进程不可写
shared->written = 1;
memset(shared->users[mylocal], 0, USER_LEN);
do
{
//找到@时
if (rindex(shared->users[i],'@') != 0)
{
//memset(shared->users[i], 0, USER_LEN);
break;
}
} while (++i < USER_NUM);
//写完数据,设置written使共享内存段可读
shared->written = 0;
shmdetach((void *)shared);
//如果已没有用户在线,则销毁
if (i == USER_NUM)
{
//此处暂未解决“不能其他用户创建的共享内存”的问题,所有注释掉
//shmdestroy(shmid);
}
return 0;
}
int shmuserlist(struct shared_users_st *shared)
{
//struct shared_users_st *shared = NULL;
int i = 0;
//设置共享内存
//shared = (struct shared_users_st*)shm;
//数据还没有被读取,则等待数据被读取,不能向共享内存中写入文本
//waitwrite(shared);
//向共享内存中写入数据前先置1,其它进程不可写
//shared->written = 1;
printf(" zz%s\n", "zzzzzzzzzzzzzzzzzzzzzzzzzzzz");
do
{
//找到@时
if (rindex(shared->users[i],'@') != 0)
{
printf(" zz %d %s\n", i, shared->users[i]);
//break;
}
} while (++i < USER_NUM);
printf(" zz%s\n", "zzzzzzzzzzzzzzzzzzzzzzzzzzzz");
//写完数据,设置written使共享内存段可读
//shared->written = 0;
return 0;
}
int shmusermsg(struct shared_users_st *shared, char *buffer)
{
//struct shared_users_st *shared = NULL;
int i = 0;
char buff[BUFSIZ + 1];//用于保存输入的文本
//设置共享内存
//shared = (struct shared_users_st*)shm;
//数据还没有被读取,则等待数据被读取,不能向共享内存中写入文本
//waitwrite(shared);
//向共享内存中写入数据前先置1,其它进程不可写
//shared->written = 1;
if (!ishidden)
{
sprintf( buff, " ** %s: %s", getuser(), buffer);
strcpy(buffer, buff);
}
do
{
//找到@时
if (rindex(shared->users[i],'@') != 0 ) //&& i != mylocal
{
char *p;
int fd;
//发送给其它用户时,换行\n后输出
if (i != mylocal)
{
sprintf( buff, "%s", buffer);
}
else
{
//\033[1A 先回到上一行 //\033[K 清除该行
sprintf( buff, "\033[1A\033[K%s", buffer);
}
//strcpy(buffer, buff);
//printf("%s %s %d\n", __FUNCTION__, strchr(shared->users[i],'@')+1, i);
if ((p = strchr(shared->users[i],'@')) == 0)
{
//perror("open error");
continue;
}
//发送消息之前先判断该用户是否在线
if ((fd = open(p+1, O_WRONLY)) < 0)
{
perror("open error");
printf("%s\n", shared->users[i]);
//exit(EXIT_FAILURE);
}
if (write(fd, buff, strlen(buff)+1) != strlen(buff)+1)
{
perror("write error");
//exit(EXIT_FAILURE);
}
close(fd);
//break;
}
} while (++i < USER_NUM);
//写完数据,设置written使共享内存段可读
//shared->written = 0;
return 0;
}
//在utmp文件(当前在线用户,即w命令展示结果)中找到返回非0,未找到返回0
bool userinutmp(char *userinfo)
{
struct utmp *u;
char *p, *tty, user[USER_LEN];
memset(user, 0, USER_LEN);
strncpy(user, userinfo, strlen(userinfo));
p = strtok(user, "@");
//user = p;
p = strtok(NULL, "@");
tty = p;
//printf("%s %s %s.\n", user, tty, userinfo);
struct utmp ut;
strcpy (ut.ut_line,tty+5);
while ((u=getutline(&ut)))
{
//printf("-%d %s %s %s \n",u->ut_type,u->ut_user,u->ut_line,u->ut_host);
//如果找到匹配
if (!strcmp(u->ut_user, user))
{
endutent();
return true;
}
}
endutent();
return false;
}
#if 1
void pwentinfo()
{
struct passwd *user;
if((user = getpwuid(geteuid()))!=0)
{
printf("%s:%d:%d:%s:%s:%s\n",user->pw_name,user->pw_uid,user->pw_gid,
user->pw_gecos,user->pw_dir,user->pw_shell);
}
endpwent();
printf("uid is %d\n",getpgid(getegid()));
printf("egid is %d\n",getegid());
printf("gid is %d\n",getpgrp());
}
#endif
标签:struct,buffer,编程,网络,int,printf,shared,users
From: https://www.cnblogs.com/HappyTeemo/p/18509838