c語言socket雙向通信+一服務(wù)端對多客戶端通信

任務(wù)

在完成socket客戶端對服務(wù)端的通信以后,又讓我搞雙向通信,然后又是讓我用app去控制gpio口的高低變化.努力了三天,從socket的學(xué)習(xí)到多線程的學(xué)習(xí),一步一步的完成了任務(wù),測試從app到服務(wù)器在到小板上的數(shù)據(jù)流全部打通.下班之前記錄一下.

思路

socket雙向通信使用的方法是服務(wù)端開啟服務(wù)等客戶端連接上以后開辟一個線程,然后把客戶端套接字client_sockfd傳遞過去,輸入數(shù)據(jù)后發(fā)送給客戶端.反之亦然.
一服務(wù)端對多客戶端的通信采用select.參考博客見:http://blog.csdn.net/ctrl_qun/article/details/52524086 作者寫的非常棒,講解的也很全面,繼續(xù)研讀中.對它的代碼進(jìn)行了部分改進(jìn).添加了對客戶端上傳的數(shù)據(jù)下發(fā)到所有的客戶端,這個是我項目中的需求.然后添加了一個頭文件.因為有些即用即初始化的參數(shù),所以需要使用c99的標(biāo)準(zhǔn)去編譯.

gcc?-std=c99?client.c?-o?client

雙向通信

/*代碼里面有部分我對驅(qū)動程序的相關(guān)控制*/
/*socket端*/
#include#include#include#include#include#include#include#include#include#include#include#define?MAXBUF?512

#define?DEV_IOC_MAGIC?'0xee'?//定義幻數(shù)


#define?DEV_IOCPRINT??_IO(DEV_IOC_MAGIC,?1)
#define?DEV_IO_HIGH???_IO(DEV_IOC_MAGIC,?2)
#define?DEV_IO_LOW????_IO(DEV_IOC_MAGIC,?3)

#define?DEV_IOC_MAXNR?3

char?send_buf[MAXBUF+1];
int?fd;
void?*thread(void?*x)??
{???
????int?cmd;
????char?buf[BUFSIZ];
????int?new_fd?=?*((int*)x);
????while(recv(new_fd,buf,BUFSIZ,0)>0)
????{
????????//int?len=recv(new_fd,buf,BUFSIZ,0);
????????if(strcmp(buf,"1")==0)
????????{
????????????printf("n");
????????????cmd?=?DEV_IO_HIGH;
????????????if?(ioctl(fd,?cmd)?<?0)
????????????{
????????????????printf("Call?cmd?DEV_IO_HIGH?failn");
????????????}
????????????printf("NOW,GPIO?is?High.n");
????????}
????????if(strcmp(buf,"0")==0)
????????{
????????????printf("n");
????????????cmd?=?DEV_IO_LOW;
????????????if?(ioctl(fd,?cmd)?<?0)
????????????{
????????????????printf("Call?cmd?DEV_IO_LOW?failn");
????????????}
????????????printf("NOW,GPIO?is?Low.n");
????????}
????????printf("client:received:%sn",buf);
????}
????/*while(1)
????{
????????bzero(send_buf,?MAXBUF?+?1);
????????scanf("%s",send_buf);
????????send(new_fd,?send_buf,?strlen(send_buf),?0);?//第?4?步?向套接字中寫入字符串
????}*/
????return?NULL;??
}

void?open_dev()
{
????fd?=?open("/dev/dsx",?O_RDWR);
????if(fd?<?0)
????????printf("/dev/dsx?is?open?fail!n");
}

int?main(int?argc,?char?*argv[])
{
????int?client_sockfd;
????int?len;
????struct?sockaddr_in?remote_addr;?//服務(wù)器端網(wǎng)絡(luò)地址結(jié)構(gòu)體
????char?buf[BUFSIZ];??//數(shù)據(jù)傳送的緩沖區(qū)
????memset(&remote_addr,0,sizeof(remote_addr));?//數(shù)據(jù)初始化--清零
????remote_addr.sin_family=AF_INET;?//設(shè)置為IP通信
????remote_addr.sin_addr.s_addr=inet_addr("0.0.0.0");//服務(wù)器IP地址
????remote_addr.sin_port=htons(8000);?//服務(wù)器端口號
????open_dev();
????/*創(chuàng)建客戶端套接字--IPv4協(xié)議，面向連接通信，TCP協(xié)議*/
????if((client_sockfd=socket(PF_INET,SOCK_STREAM,0))<0)
????{
????????perror("socket");
????????return?1;
????}

????/*將套接字綁定到服務(wù)器的網(wǎng)絡(luò)地址上*/
????if(connect(client_sockfd,(struct?sockaddr?*)&remote_addr,sizeof(struct?sockaddr))<0)
????{
????????perror("connect");
????????return?1;
????}
????printf("connected?to?servern");
????//len=recv(client_sockfd,buf,BUFSIZ,0);//接收服務(wù)器端信息
????//?????buf[len]='