我写了一个简单的聊天程序，服务器和客户端接受发送数据都通过定义的同一个结构体，为什么在本机测试，开两个终端都没有问题，客户端和服务器分开在不同的电脑上测试时，客户端发送数据正常，而此时服务器收到的结构体里的数据为空是怎么回事？服务器用的epoll单线程，客户端用的双线程
服务器代码
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include"message.h"
#define PORT 6666 //服务器端口
#define LISTEN_SIZE 1024 //连接请求队列的最大长度
#define EPOLL_SIZE 1024 //监听的客户端的最大数目
#define BUF_MAX 257 //读取缓存区最大字节
time_t timep; //记录当前时间
typedef struct cli_data //记录在线用户信息的结构体
{
int cli_fd; //记录连接的用户套接字
char username[21]; //记录账号，最大20位
struct cli_data* next;
}cli_data;
typedef struct user //记录用户账号信息的结构体
{
char username[21];
char pwd[21];
}user;
typedef struct group
{
char username[100][21];
int groupfd[100];
char groupname[21];
int n;
}group;
group taolun[100]; //全局讨论组
char* my_time() //输出当前时间
{
time(&timep);
char* p=ctime(&timep);
return p;
}
cli_data* head; //创建头结点
cli_data* create() //创建一个带头节点的链表，储存已连接的用户
{
cli_data* head;
head=(cli_data*)malloc(sizeof(struct cli_data));
head->next=NULL;
return head;
}
cli_data* insert() //插入链表
{
cli_data* temp=head;
cli_data* new;
new=(cli_data*)malloc(sizeof(cli_data));
new->next=NULL;
while(temp->next!=NULL)
{
temp=temp->next;
}
temp->next=new;
return new;
}
void delete(cli_data* head,int cli_fd) //链表的删除
{
cli_data* temp,*last;
temp=head->next;
last=head;
while(temp!=NULL&&temp->cli_fd!=cli_fd)
{
last=temp;
temp=temp->next;
}
if(temp!=NULL&&temp->cli_fd==cli_fd)
{
last->next=temp->next;
free(temp);
}
}
void my_err(char* string)
{
perror(string);
exit(1);
}
void my_path(char*dir,char* filename,char* path) //将目录和文件名连接成一个路径
{
strcpy(path,dir);
strcat(path,"/");
strcat(path,filename);
}
void send_message(struct message recv_buf,int conn_fd) //向客户端发送信息
{
struct message send_buf;
send_buf=recv_buf;
int n=send_buf.n;
int fd;
struct user user_data;
int ret=0; //用来表示注册账号是否存在或账号密码信息是否匹配
FILE* fp;
cli_data* temp; //在线用户链表临时指针
char path[256]; //储存文件路径
char friendname[21]; //储存用户好友用户名
int i=0;
fp=fopen("passwd.txt","a+");
fclose(fp);
switch(n)
{
case 0: { //注册账号
if((fd=open("passwd.txt",O_RDWR|O_APPEND))<0)
{
my_err("open");
}
while(read(fd,&user_data,sizeof(struct user))>0)
{
if(strcmp(user_data.username,send_buf.username)==0)
{
send_buf.n=-2;
ret=1;
break;
}
}
if(!ret)
{
strcpy(user_data.username,recv_buf.username);
strcpy(user_data.pwd,recv_buf.pwd1);
send_buf.n=22;
if(write(fd,&user_data,sizeof(struct user))<0)
{
my_err("write");
}
close(fd);
int fd,stdoutfd;
fd=open("log_file",O_RDWR|O_CREAT|O_APPEND);
stdoutfd=dup(1);
printf("a user register,username:%s,time:%s",user_data.username,my_time());
dup2(fd,1);
printf("a user register,username:%s,time:%s",user_data.username,my_time());
dup2(stdoutfd,1);
close(fd);
close(stdoutfd);
mkdir(user_data.username,07777); //创建用户所属目录
my_path(user_data.username,user_data.username,path);
fd=open(path,O_RDWR|O_CREAT|O_APPEND,0777);
if(fd<0)
{
printf("创建用户好友文件失败\n");
}
close(fd);
}
if(send(conn_fd,&send_buf,sizeof(struct message),0)<0)
{
printf("向客户端发送数据失败\n");
}
break;
}
case 1: {//登陆
if((fd=open("passwd.txt",O_RDONLY))<0)
{
my_err("open");
}
while(read(fd,&user_data,sizeof(struct user))>0)
{
if(strcmp(user_data.username,send_buf.username)==0)
{
if(strcmp(user_data.pwd,send_buf.pwd1)==0)
{
ret=1;
break;
}
}
}
if(ret)
send_buf.n=11;
else
send_buf.n=-1;
if(send(conn_fd,&send_buf,sizeof(struct message),0)<0)
{
printf("向客户端发送数据失败\n");
return;
}
if(send_buf.n==11)
{
int fd,stdoutfd;
fd=open("log_file",O_CREAT|O_RDWR|O_APPEND);
printf("a user is login,username:%s,time:%s",send_buf.username,my_time());
stdoutfd=dup(1);
dup2(fd,1);
printf("a user is login,username:%s,time:%s",send_buf.username,my_time());
dup2(stdoutfd,1);
close(fd);
close(stdoutfd);
temp=insert();
temp->cli_fd=conn_fd;
strcpy(temp->username,send_buf.username);
my_path("lixian",send_buf.username,path); //发送离线消息
fd=open(path,O_RDONLY);
if(fd>0)
{
send_buf.n=6;
while(read(fd,send_buf.time,sizeof(send_buf.time))!=0)
{
read(fd,send_buf.from,sizeof(send_buf.from));
read(fd,send_buf.chat,sizeof(send_buf.chat));
if(send(conn_fd,&send_buf,sizeof(struct message),0)<0)
{
printf("向客服端发送离线消息失败\n");
return;
}
}
close(fd);
fd=open(path,O_RDWR|O_CREAT|O_TRUNC);
close(fd);
}
}
break;
}
case 3: { //添加好友
temp=head->next;
my_path(send_buf.from,send_buf.from,path); //防止重复添加好友
fd=open(path,O_RDONLY);
if(fd<0)
{
printf("打开用户好友文件失败\n");
return;
}
while(read(fd,friendname,sizeof(friendname))!=0)
{
if(strcmp(friendname,send_buf.to)==0)
{
send_buf.n=-3;
if(send(conn_fd,&send_buf,sizeof(struct message),0)<0)
{
printf("向客户端发送数据失败\n");
return;
}
close(fd);
return;
}
}
while(temp!=NULL)
{
if(strcmp(temp->username,send_buf.to)==0) //找到指定在线好友
{
ret=1;
break;
}
temp=temp->next;
}
if(ret)
{
int to_fd=temp->cli_fd; //向另一用户征求是否同意添加好友
send(to_fd,&send_buf,sizeof(struct message),0);
recv(to_fd,&send_buf,sizeof(struct message),0);
if(send_buf.n==33)
{
my_path(send_buf.from,send_buf.from,path);//写入用户好友文件
fd=open(path,O_RDWR|O_APPEND);
if(write(fd,&send_buf.to,sizeof(send_buf.to))<0)
{
printf("写入用户好友失败\n");
send_buf.n=-3;
}
close(fd);
my_path(send_buf.from,send_buf.to,path); //创建用户与该好友的聊天记录文件
fd=open(path,O_RDWR|O_CREAT|O_TRUNC,0777);
close(fd);
my_path(send_buf.to,send_buf.to,path); //写入另一用户好友文件
fd=open(path,O_RDWR|O_APPEND);
write(fd,&send_buf.from,sizeof(send_buf.from));
close(fd);
my_path(send_buf.to,send_buf.from,path); //创建另一用户与该好友的聊天记录文件
fd=open(path,O_RDWR|O_CREAT|O_TRUNC,0777);
close(fd);
}
}
else
send_buf.n=-3;
if(send(conn_fd,&send_buf,sizeof(struct message),0)<0)
{
printf("send error\n");
}
break;
}
case 4: {//查看好友列表
my_path(recv_buf.username,recv_buf.username,path); //连接用户好友文件路径
fd=open(path,O_RDONLY);
while(read(fd,send_buf.friendname[i++],sizeof(recv_buf.username))!=0);
send_buf.friendname[i][0]='\0';
if(send(conn_fd,&send_buf,sizeof(struct message),0)<0)
{
printf("send error\n");
}
break;}
case 44: { //查看在线好友
my_path(recv_buf.username,recv_buf.username,path); //连接用户好友文件路径
fd=open(path,O_RDONLY);
while(read(fd,friendname,sizeof(friendname))!=0)
{
int n=0;
temp=head->next;
while(temp!=NULL)
{
if(strcmp(temp->username,friendname)==0)
{
n=1;
break;
}
else
temp=temp->next;
}
if(n)
{
strcpy(send_buf.friendname[i++],friendname);
}
}
send_buf.friendname[i][0]='\0';
if(send(conn_fd,&send_buf,sizeof(struct message),0)<0)
{
printf("send error\n");
}
break;
}
case 5: //删除好友
{
int i=0;
int ret=0;
my_path(send_buf.from,send_buf.from,path);
fd=open(path,O_RDONLY);
if(fd<0)
{
printf("打开用户好友文件失败\n");
send_buf.n=-5;
}
while(read(fd,send_buf.friendname[i++],sizeof(send_buf.username))!=0)
send_buf.friendname[i][0]='\0';
i=0;
close(fd);
while(strlen(send_buf.friendname[i])!=0)
{
if(strcmp(send_buf.friendname[i],send_buf.to)==0)
{
strcpy(send_buf.friendname[i],"\n");
ret++;
}
i++;
}
fd=open(path,O_RDWR|O_CREAT|O_TRUNC);
if(fd<0)
{
printf("打开用户好友文件失败\n");
send_buf.n=-5;
}
i=0;
while(strlen(send_buf.friendname[i])!=0)
{
if(strcmp(send_buf.friendname[i],"\n")!=0)
{
if(write(fd,send_buf.friendname[i],sizeof(send_buf.username))<0)
{
printf("写入用户好友文件失败\n");
send_buf.n=-5;
}
}
i++;
}
close(fd);
i=0;
my_path(send_buf.to,send_buf.to,path);
fd=open(path,O_RDONLY); //读取删除对象的好友列表
if(fd<0)
{
printf("打开删除对象好友文件失败\n");
send_buf.n=-5;
}
while(read(fd,send_buf.friendname[i++],sizeof(send_buf.username))!=0);
send_buf.friendname[i][0]='\0';
close(fd);
i=0;
while(strlen(send_buf.friendname[i])!=0)
{
if(strcmp(send_buf.friendname[i],send_buf.from)==0)
strcpy(send_buf.friendname[i],"\n");
i++;
}
i=0;
fd=open(path,O_RDWR|O_CREAT|O_TRUNC);
if(fd<0)
{
printf("打开删除对象好友文件失败\n");
send_buf.n=-5;
}
while(strlen(send_buf.friendname[i])!=0)
{
if(strcmp(send_buf.friendname[i],"\n")!=0)
{
if(write(fd,send_buf.friendname[i],sizeof(send_buf.username))<0)
{
printf("写入删除对象好友文件失败\n");
send_buf.n=-5;
}
}
i++;
}
close(fd);
ret++;
if(ret==2)
send_buf.n=55;
else
send_buf.n=-5;
if(send(conn_fd,&send_buf,sizeof(struct message),0)<0)
{
printf("向客户端发送信息失败\n");
return;
}
break;
}
case 6: //私聊
{
int i=0,ret=0;
my_path(send_buf.from,send_buf.from,path);
fd=open(path,O_RDONLY);
while(read(fd,send_buf.friendname[i++],sizeof(send_buf.username))!=0);
send_buf.friendname[i][0]='\0';
close(fd);
i=0;
while(strlen(send_buf.friendname[i])!=0)
{
if(strcmp(send_buf.friendname[i],send_buf.to)==0)
{
ret=1;
break;
}
i++;
}
if(ret)
{
temp=head->next;
while(temp!=NULL)
{
if(strcmp(temp->username,send_buf.to)==0)
{
my_path(send_buf.from,send_buf.to,path);
fd=open(path,O_RDWR|O_CREAT|O_APPEND);
if(fd<0)
{
printf("打开记录用户聊天记录文件失败\n");
}
if(send(temp->cli_fd,&send_buf,sizeof(struct message),0)<0)
{
printf("发送用户消息失败\n");
return;
}
else
{
int stdoutfd=dup(1);
dup2(fd,1);
printf("%s",send_buf.time);
printf("我@%s:%s\n",send_buf.to,send_buf.chat);
dup2(stdoutfd,1);
close(fd);
my_path(send_buf.to,send_buf.from,path);
open(path,O_RDWR|O_CREAT|O_APPEND);
if(fd<0)
{
printf("打开记录用户聊天记录文件失败\n");
return;
}
dup2(fd,1);
printf("%s",send_buf.time);
printf("%s@我:%s\n",send_buf.from,send_buf.chat);
dup2(stdoutfd,1);
close(fd);
close(stdoutfd);
return;
}
}
temp=temp->next;
}
my_path("lixian",send_buf.to,path);
fd=open(path,O_RDWR|O_CREAT|O_APPEND,0777);
if(fd<0)
{
printf("打开指定用户离线消息文件\n");
return;
}
write(fd,send_buf.time,sizeof(send_buf.time));
write(fd,send_buf.from,sizeof(send_buf.from));
write(fd,send_buf.chat,sizeof(send_buf.chat));
close(fd);
}
else
{
send_buf.n=-6;
if(send(conn_fd,&send_buf,sizeof(struct message),0)<0)
{
printf("向客户端发送信息失败\n");
return;
}
}
break;
}
case 77: //创建讨论组
{
int i=1;
while(taolun[i].n!=0)
i++;
if(i<100)
{
taolun[i].n=1;
send_buf.groupi=i;
strcpy(taolun[i].username[0],send_buf.from);
strcpy(taolun[i].groupname,send_buf.groupname);
taolun[i].groupfd[0]=conn_fd;
}
else
send_buf.n=-77;
if(send(conn_fd,&send_buf,sizeof(struct message),0)<0)
{
printf("向客户发送信息失败\n");
return;
}
break;
}
case 777: //邀请在线好友加入讨论组
{
int ret=0;
int i=0;
my_path(send_buf.from,send_buf.from,path);
fd=open(path,O_RDONLY);
if(fd<0)
{
printf("打开用户好友文件失败\n");
send_buf.n=-777;
}
while(read(fd,send_buf.friendname[i],sizeof(send_buf.username))!=0)
{
if(strcmp(send_buf.to,send_buf.friendname[i])==0)
{
ret=1;
break;
}
}
if(ret)
{
temp=head->next;
while(temp!=NULL)
{
if(strcmp(send_buf.to,temp->username)==0)
{
int j=0,k=send_buf.groupi;
send(temp->cli_fd,&send_buf,sizeof(struct message),0);
while(taolun[k].groupfd[j]!=0)
{
j++;
}
taolun[k].groupfd[j]=temp->cli_fd;
strcpy(taolun[k].username[j],send_buf.to);
return;
}
temp=temp->next;
}
}
send_buf.n=-777;
send(conn_fd,&send_buf,sizeof(struct message),0);
break;
}
case 7: //群聊
{
int i=send_buf.groupi,j=0;
while(taolun[i].groupfd[j]!=0)
{
if(taolun[i].groupfd[j]!=conn_fd&&taolun[i].groupfd[j]!=-1)
{
send(taolun[i].groupfd[j],&send_buf,sizeof(struct message),0);
}
j++;
}
break;
}
case -7: //退出讨论组
{
int i=send_buf.groupi,j=0;
while(taolun[i].groupfd[j]!=conn_fd)
{
j++;
}
if(j==0)
{
j=1;
send_buf.n=-7777;
while(taolun[i].groupfd[j]!=0&&taolun[i].groupfd[j]!=-1)
{
send(taolun[i].groupfd[j],&send_buf,sizeof(struct message),0);
j++;
}
taolun[i].n=0;
memset(&taolun[i],0,sizeof(taolun[i]));
}
else
taolun[i].groupfd[j]=-1;
break;
}
case 7777: //查看讨论组成员
{
int i=send_buf.groupi,j=0,k=0;;
while(taolun[i].groupfd[j]!=0&&taolun[i].groupfd[j]!=-1)
{
strcpy(send_buf.friendname[k++],taolun[i].username[j]);
j++;
}
send_buf.friendname[k][0]='\0';
send(conn_fd,&send_buf,sizeof(struct message),0);
break;
}
case 8: //查看与好友聊天记录
{
int j=0,ret=0;
send_buf.n=-8;
temp=head->next;
my_path(send_buf.from,send_buf.from,path);
fd=open(path,O_RDONLY);
while(read(fd,send_buf.friendname[j++],sizeof(send_buf.username))!=0);
send_buf.friendname[j][0]='\0';
j=0;
while(strlen(send_buf.friendname[j])!=0)
{
if(strcmp(send_buf.to,send_buf.friendname[j])==0)
{
ret=1;
break;
}
j++;
}
if(ret)
{
FILE * fp;
j=0;
my_path(send_buf.from,send_buf.to,path);
fp=fopen(path,"r+");
while(!feof(fp))
{
fgets(send_buf.chathistory[j],10000,fp);
j++;
if(j==100)
break;
}
send_buf.n=8;
}
if(send(conn_fd,&send_buf,sizeof(struct message),0)<0)
{
printf("向客户端发送数据失败\n");
return;
}
}
}
}
int main()
{
int sock_fd,conn_fd; //储存套接字
struct sockaddr_in cli_addr,serv_addr;
struct message recv_buf; //读取缓存区
socklen_t cli_len;
int epollfd;
struct epoll_event event;
struct epoll_event* events;
int fd;
memset(taolun,0,sizeof(taolun));
fd=open("log_file",O_RDWR|O_CREAT|O_APPEND);
close(fd);
//创建一个套接字
sock_fd=socket(AF_INET,SOCK_STREAM,0);
if(sock_fd<0)
{
my_err("socket");
}
//设置该套接字使之可以重新绑定端口
int optval=1;
if(setsockopt(sock_fd,SOL_SOCKET,SO_REUSEADDR,(void*)&optval,sizeof(int))<0)
{
my_err("setsockopt");
}
//初始化服务器端地址结构
memset(&serv_addr,0,sizeof(struct sockaddr_in));
serv_addr.sin_family=AF_INET;
serv_addr.sin_port=htons(PORT);
serv_addr.sin_addr.s_addr=htonl(INADDR_ANY);
if(bind(sock_fd,(struct sockaddr*)&serv_addr,sizeof(struct sockaddr_in))<0)
{
my_err("bind");
}
//将套接字转化为监听套接字
if(listen(sock_fd,LISTEN_SIZE)<0)
{
my_err("listen");
}
cli_len=sizeof(struct sockaddr_in);
events=(struct epoll_event*)malloc(sizeof(struct epoll_event)*EPOLL_SIZE);
//创建一个监听描述符epoll,并将监听套接字加入
epollfd=epoll_create(EPOLL_SIZE);
if(epollfd==-1)
{
my_err("epoll_create");
}
event.events = EPOLLIN;
event.data.fd = sock_fd;
if(epoll_ctl(epollfd,EPOLL_CTL_ADD,sock_fd,&event)<0)
{
my_err("epoll_ctl");
}
mkdir("lixian",0777); //创建离线消息目录
head=create(); //创建链表
while(1)
{
int sum=0,i;
sum=epoll_wait(epollfd,events,EPOLL_SIZE,-1);
for(i=0;i<sum;i++)
{
if(events[i].data.fd==sock_fd) //有请求连接
{
int fd,stdoutfd;
fd=open("log_file",O_RDWR|O_CREAT|O_APPEND);
stdoutfd=dup(1);
conn_fd=accept(sock_fd,(struct sockaddr*)&cli_addr,&cli_len);
if(conn_fd<0)
{
my_err("accept");
}
event.events = EPOLLIN | EPOLLRDHUP;
event.data.fd = conn_fd;
if(epoll_ctl(epollfd,EPOLL_CTL_ADD,conn_fd,&event)<0) //将新连接的套接字加入监听
{
my_err("epoll_ctl");
}
printf("a connet is connected,ip is %s,time:%s",inet_ntoa(cli_addr.sin_addr),my_time());
dup2(fd,1);
printf("a connet is connected,ip is %s,time:%s",inet_ntoa(cli_addr.sin_addr),my_time());
dup2(stdoutfd,1);
close(fd);
close(stdoutfd);
}
else if(events[i].events&EPOLLIN) //有可读的套接字
{
memset(&recv_buf,0,sizeof(struct message));
recv(events[i].data.fd,&recv_buf,sizeof(struct message),0);
send_message(recv_buf,events[i].data.fd);
}
if(events[i].events&EPOLLRDHUP)
{
int fd,stdoutfd;
fd=open("log_file",O_RDWR|O_CREAT|O_APPEND);
stdoutfd=dup(1);
delete(head,events[i].data.fd);
printf("a connet is quit,ip is %s,time:%s",inet_ntoa(cli_addr.sin_addr),my_time());
dup2(fd,1);
printf("a connet is quit,ip is %s,time:%s",inet_ntoa(cli_addr.sin_addr),my_time());
dup2(stdoutfd,1);
close(fd);
close(stdoutfd);
epoll_ctl(epollfd,EPOLL_CTL_DEL,events[i].data.fd,&event);
close(events[i].data.fd);
}
}
}
return 0;
}
http://blog.csdn.net/baidu_24014585/article/details/52244643
这是我前几天写的，以测试了
电脑是否在同一个局域网内，是否被防火墙屏蔽，端口号有没有被占用