Server：
设置可聊天数为5，为每一个client创建一个线程，这个线程负责接收client的聊天内容并发给其他用户看。
用mutex同步各个线程修改聊天室空余聊天位。
Client：
主线程负责向server发送自己的内容，开一个线程负责接收server发过来别人聊天的内容。
client.c
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/un.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <pthread.h> char recv_buf[],send_buf[]; void pthread_function(void* sock_fd){
int sockfd=*(int*)sock_fd;
long recvbytes;
while() {
if((recvbytes=recv(sockfd,recv_buf,,))==-){
printf("recv error");
exit();
}
else{
recv_buf[recvbytes]='\0';
printf("%s\n",recv_buf);
}
}
}
int main(void){
pthread_t id;
int sockfd;
struct sockaddr_in sever_addr; sever_addr.sin_family=AF_INET;
sever_addr.sin_port=htons();
sever_addr.sin_addr.s_addr=inet_addr("10.144.20.79"); if((sockfd=socket(AF_INET,SOCK_STREAM,))==-){
printf("socket error");
exit();
}
if(connect(sockfd,(struct sockaddr*)&sever_addr,sizeof(sever_addr))==-){
printf("connect error");
exit();
}
char name[];
printf("please input your name\n");
scanf("%s",name);
send(sockfd,name,strlen(name),); if(pthread_create(&id,NULL,(void*)pthread_function,(void*)&sockfd)!=)
printf("create thread error\n");
while(){
scanf("%s",send_buf);
fflush(stdin);
if(send(sockfd,send_buf,strlen(send_buf),)==-){
printf("send error");
exit();
}
sleep();
}
close(sockfd);
pthread_cancel(id);
return ;
}
server.c
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/un.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <netinet/in.h>
#include <pthread.h> #define COUNT 5
int socket_fd[COUNT]={,-,-,-,-};
pthread_mutex_t emptymutex; int empty=;
/*
the fuction for the thread
*/ void pthread_function(void* clientfd){
char message[];
char buf[];
int i;
long recvbytes;
char name[];
int client_fd=*(int*)clientfd; pthread_mutex_lock(&emptymutex);
if(empty>)
empty--;
else pthread_exit(NULL);
pthread_mutex_unlock(&emptymutex); /*first connect,need to save the name of clients*/
recvbytes=recv(client_fd,name,,);
name[recvbytes]=':';
name[recvbytes+]='\0';
send(client_fd,"welcome to this chatroom,enjoy chatting:",,); while(){
if((recvbytes=recv(client_fd,buf,,))==-){
perror("recv");
pthread_exit(NULL);
}
if(recvbytes==){
printf("%sbye\n",name);
break;
}
buf[recvbytes]='\0';
for (i = ; i < COUNT; ++i)
{
int tmpclient=socket_fd[i];
if(tmpclient!=-){
message[]='\0';
strcat(message,name);
strcat(message,buf);
if(send(tmpclient,message,strlen(message),)==-){
perror("send error");
pthread_exit(NULL);
}
}
}
}
//close socket and reset the fd -1
close(client_fd); pthread_mutex_lock(&emptymutex);
if(empty<)
empty++;
else pthread_exit(NULL);
pthread_mutex_unlock(&emptymutex);
for (i = ; i < COUNT; ++i)
{
if(socket_fd[i]==client_fd)
socket_fd[i]=-;
}
pthread_exit(NULL);
} int main(){
int i;
pthread_mutex_init(&emptymutex,NULL); pthread_t id;
int sockfd,client_fd;
socklen_t sin_size;
struct sockaddr_in my_addr;
struct sockaddr_in remote_addr;
if((sockfd=socket(AF_INET,SOCK_STREAM,))==-){
perror("socket");
exit();
} my_addr.sin_family=AF_INET;
my_addr.sin_port=htons();
my_addr.sin_addr.s_addr=htonl(INADDR_ANY);
bzero(&(my_addr.sin_zero),); if(bind(sockfd,(struct sockaddr*)&my_addr,sizeof(struct sockaddr))==-){
perror("bind");
exit();
} if(listen(sockfd,)==-){
perror("listen");
exit();
} i=;
while(){
sin_size=sizeof(struct sockaddr_in);
if((client_fd=accept(sockfd,(struct sockaddr*)&remote_addr,&sin_size))==-){
perror("accept");
exit();
}
if(empty>){
while(socket_fd[i]==-)
i=(i+)%COUNT;
socket_fd[i]=client_fd;
pthread_create(&id,NULL,(void*)pthread_function,(void*)&client_fd);}
else break;
}
pthread_mutex_destroy(&emptymutex);
return ;
}
注意点：
- sockaddr和sockaddr_in的区别
- htonl(INADDR_ANY)设置ip为0.0.0.0，这样会监听所有端口
- server是:socket-bind-listen-accpet-send/recv-close；client是:socket-connect-send/recv-close。
- pthread_create()第三个参数是void*,如果想用int，可以int var=*(int*)client_fd
- bind:address in use是端口已经被打开
- 线程里用pthread_exit(NULL)如果用exit连主线程都会退出
还要改，现在新开一个client可以接受老client的内容，但是老client接收不到新client的内容。还有就是client输入一个什么特定的字符表示结束，以close(socket).