linux socket 本地进程间通信---笔记

摘要：
本文代码，转自另外一篇博客：Linux进程间通信方式–本地socket

服务端

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h> 
#define UNIX_DOMAIN "/data/UNIX.domain"
static void refresh_server(void)
{
	socklen_t clt_addr_len;
	int listen_fd;
	int com_fd;
	int ret;
	int i;
	static char recv_buf[1024]; 
	int len;
	struct sockaddr_un clt_addr;
	struct sockaddr_un srv_addr;
	listen_fd = socket(PF_UNIX,SOCK_STREAM,0);
	if (listen_fd < 0)
	{
		perror("cannot create communication socket");
		return 1;
	}  
	//set server addr_param
	srv_addr.sun_family=AF_UNIX;
	strncpy(srv_addr.sun_path,UNIX_DOMAIN,sizeof(srv_addr.sun_path)-1);
	unlink(UNIX_DOMAIN);
	//bind sockfd & addr
	ret = bind(listen_fd,(struct sockaddr*)&srv_addr,sizeof(srv_addr));
	if (ret == -1)
	{
		perror("cannot bind server socket");
		close(listen_fd);
		unlink(UNIX_DOMAIN);
		return 1;
	}
	//listen sockfd 
	ret = listen(listen_fd,1);
	if (ret == -1)
	{
		perror("cannot listen the client connect request");
		close(listen_fd);
		unlink(UNIX_DOMAIN);
		return 1;
	}
	//have connect request use accept
	len = sizeof(clt_addr);
	com_fd = accept(listen_fd,(struct sockaddr*)&clt_addr,&len);
	if (com_fd < 0)
	{
		perror("cannot accept client connect request");
		close(listen_fd);
		unlink(UNIX_DOMAIN);
		return 1;
	}
	//read and printf sent client info
	printf("\n=====info=====\n");
	//for (i = 0; i < 4; i++)
	{
		memset(recv_buf,0,1024);
		int num = read(com_fd,recv_buf,sizeof(recv_buf));
		if (num <= 0) {
			printf("read nothing!\n");
			//break;
		}
		printf("Message from client (%d)) :%s\n",num,recv_buf);
		// To refresh picture
		// TODO...
	}
	close(com_fd);
	close(listen_fd);
	unlink(UNIX_DOMAIN);
	return 0;  
}

//

int main(int argc,  char **argv) 
{
	int fd = -1;


	fd = open(UNIX_DOMAIN, O_RDWR | O_APPEND | O_CREAT,0755);
	if (fd >= 0)
	{
		write(fd, " ", 1); // one space;
		fsync(fd);
		close(fd);
	} 
	else  
	{
		printf("creat\open %s faild!\n",UNIX_DOMAIN);
	}

	while(1) {
      /*Just to let the system breath*/
		refresh_server();
		usleep(1000);
	}
	return   0;//EXIT_SUCCESS;
}

客户端

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#define UNIX_DOMAIN "/data/UNIX.domain"
int main(void)
{
    int connect_fd;
    int ret;
    char snd_buf[1024];
	char input[32];
    int i;
    static struct sockaddr_un srv_addr;
//creat unix socket
    connect_fd = socket(PF_UNIX,SOCK_STREAM,0);
    if (connect_fd < 0)
    {
        perror("cannot create communication socket");
        return 1;
    }   
    srv_addr.sun_family = AF_UNIX;
    strcpy(srv_addr.sun_path,UNIX_DOMAIN);
//connect server
    ret = connect(connect_fd,(struct sockaddr*)&srv_addr,sizeof(srv_addr));
    if (ret == -1)
    {
        perror("cannot connect to the server");
        close(connect_fd);
        return 1;
    }
    memset(snd_buf,0,1024);
	memset(input, 0, sizeof(input));
    strcpy(snd_buf,"message from client");
	printf("please input words less than 32:\n");
	scanf("%s",input);
	strncat(snd_buf, input, strlen(input));
	write(connect_fd,snd_buf,sizeof(snd_buf));
/* //send info server
    for (i = 0; i < 4; i++) {
        write(connect_fd,snd_buf,sizeof(snd_buf));
	} */
    close(connect_fd);
    return 0;
}

在原作者的 demo 上稍有改动。服务端用作刷数据到 spi lcd 上；客户端用于传输要刷新的数据到服务端。因为 miniui 里面的 open_adf 调用多次的情况下，系统会 crash，故借用以上方法， open_adf 只在服务端调用一次来解决项目中问题。