Client : mini2440

Server : PC Ubuntu

网络的socket数据传输是一种特殊的I/O,socket也是一种文件描述符。socket也有一个类似于打开文件的函数：socket(),调用socket(),该函数返回一个整型的socket的描述符，随后的连接建立、数据传输等操作也都是通过该socket实现。此次测试用mini2440做Client，PC机做Server，同时连接上局域网。ping通之后，在mini2440上运行client.c，PC上运行server.c。

client.c :

#include <stdlib.h>
#include <sys/types.h>
#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>

int main()
{
	int cfd;
	int recbytes;
	int sin_size;
	char buffer[1024]={0};   
	struct sockaddr_in s_add,c_add;
	unsigned short portnum=0x8888;  //port number

	cfd = socket(AF_INET, SOCK_STREAM, 0);
	if(-1 == cfd)
	{
	    printf("socket fail ! \r\n");
	    return -1;
	}

	bzero(&s_add,sizeof(struct sockaddr_in));
	s_add.sin_family=AF_INET;
	s_add.sin_addr.s_addr= inet_addr("172.20.21.247");   //IP of your PC 
	s_add.sin_port=htons(portnum);
	printf("s_addr = %#x ,port : %#x\r\n",s_add.sin_addr.s_addr,s_add.sin_port);

	if(-1 == connect(cfd,(struct sockaddr *)(&s_add), sizeof(struct sockaddr)))
	{
	    printf("connect fail !\r\n");
	    return -1;
	}
	printf("connect ok !\r\n");

	if(-1 == (recbytes = read(cfd,buffer,1024)))
	{
	    printf("read data fail !\r\n");
	    return -1;
	}
	buffer[recbytes]='\0';
	printf("%s\r\n",buffer);
	getchar();
	close(cfd);
	return 0;
}

#include <stdlib.h>
#include <sys/types.h>
#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>

int main()
{
	int sfp,nfp;
	struct sockaddr_in s_add,c_add;
	int sin_size;
	unsigned short portnum=0x8888;     //port number
	sfp = socket(AF_INET, SOCK_STREAM, 0);

	if(-1 == sfp)
	{
	    printf("socket fail ! \r\n");
	    return -1;
	}

	printf("socket ok !\r\n");
	bzero(&s_add,sizeof(struct sockaddr_in));
	s_add.sin_family=AF_INET;
	s_add.sin_addr.s_addr=htonl(INADDR_ANY);
	s_add.sin_port=htons(portnum);

	if(-1 == bind(sfp,(struct sockaddr *)(&s_add), sizeof(struct sockaddr)))
	{
	    printf("bind fail !\r\n");
	    return -1;
	}

	if(-1 == listen(sfp,5))
	{
	    printf("listen fail !\r\n");
	    return -1;
	}
	
	while(1)
	{
		sin_size = sizeof(struct sockaddr_in);
		nfp = accept(sfp, (struct sockaddr *)(&c_add), &sin_size);
		if(-1 == nfp)
		{
		    printf("accept fail !\r\n");
		    return -1;
		}
		printf("waiting for %#x : %#x\r\n",ntohl(c_add.sin_addr.s_addr),ntohs(c_add.sin_port));
		if(-1 == write(nfp,"hello,socket\r\n",32))
		{
		    printf("write fail!\r\n");
		    return -1;
		}
		printf("write ok!\r\n");
		close(nfp);
	}
	close(sfp);
	return 0;
}

编译server.c:  gcc -o server server.c 生成server可执行文件

拷贝client到mini2440

PC机运行server：

root@desktop:~# ./server

socket ok !

mini2440运行client：

[root＠FriendlyARM ／sdcard] # ./client

s_addr = 0xf71514ac ,port : 0x8888

connect ok !

hello,socket

客户端已经收到了服务端发出的"hello,socket"的字符串

Linux socket 测试