《TCP/IP网络编程》第7章

• 半关闭shutdown函数
• 半关闭文件传输服务器端
• 半关闭文件传输客户端
• Windows实现

半关闭shutdown函数

#include <sys/socket.h>
//成功0，失败-1
int shutdown(int sock, int howto);
//SHUT_RD，断开输入流
//SHUT_WR，断开输出流
//SHUT_RDWR，断开输入输出流

半关闭文件传输服务器端

file_server.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>

#define BUF_SIZE 30
void error_handling(char *message);

int main(int argc, char *argv[]) {
	int serv_sock;
	int clnt_sock;

	FILE *fp;
	char buf[BUF_SIZE];
	int read_cnt;

	struct sockaddr_in serv_addr;
	struct sockaddr_in clnt_addr;
	socklen_t addr_size;

	if(argc!=2) {
		printf("Usage : %s <port>\n", argv[0]);
		exit(1);
	}

	serv_sock = socket(PF_INET, SOCK_STREAM, 0);
	if(serv_sock==-1)
		error_handling("socket() error");

	addr_size = sizeof(struct sockaddr_in);
	
	memset(&serv_addr, 0, serv_addr_size);
	serv_addr.sin_family = AF_INET;
	serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
	serv_addr.sin_port = htons(atoi(argv[1]));
	
	if(bind(serv_sock, (struct sockaddr*)&serv_addr, serv_addr_size)==-1)
		error_handling("bind() error");
		
	if(listen(serv_sock, 5)==-1)
		error_handling("listen() error");

	clnt_sock = accept(serv_sock, (struct sockaddr*)&clnt_addr, &addr_size );
	if(clnt_sock==-1)
		error_handling("accept() error");
		
	fp = fopen("file_serve.c", "rb");
	do {
		read_cnt = fread((void*)buf, 1, BUF_SIZE, fp);
		write(clnt_sock, buf, read_cnt);
	} while(read_cnt==BUF_SIZE);
	fclose(fp);	
	//关闭输出流，不再向客户端发送数据
	shutdown(clnt_sock, SHUT_WR);
	
	read(clnt_sock, buf, BUF_SIZE);
	printf("Message from client: %s\n", buf);

	close(clnt_sock);
	close(serv_sock);
	return 0;
}


void error_handling(char *message) {
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}

gcc file_server.c -o fserver
./fserver 9190

半关闭文件传输客户端

file_client.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>

#define BUF_SIZE 30
void error_handling(char *message);

int main(int argc, char *argv[]) {
	int sock;
	char buf[BUF_SIZE];
	int read_cnt;

	struct sockaddr_in addr;
	socklen_t addr_size;

	if(argc!=3) {
		printf("Usage : %s <IP> <port>\n", argv[0]);
		exit(1);
	}

	sock = socket(PF_INET, SOCK_STREAM, 0);
	if(sock==-1)
		error_handling("socket() error");

	addr_size = sizeof(addr);
	memset(&addr, 0, addr_size);
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = inet_addr(argv[1]);
	addr.sin_port = htons(atoi(argv[2]));
	
	if(connect(sock, (struct sockaddr*)&addr, addr_size)==-1)
		error_handling("connect() error");
		
	fp = fopen("receive.dat", "wb");
	while( (read_cnt = read(sock, buf, BUF_SIZE)) != 0 )
		fwrite((void*)buf, 1, read_cnt, fp);
	fclose(fp);
	
	puts("Received file data");
	write(sock, "Thank you", 10);
	close(sock);
	return 0;
}


void error_handling(char *message) {
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}

gcc file_client.c -o fclient
./fclient 127.0.0.1 9190

Windows实现

#include <winsock2.h>
//成功0，失败SOCKET_ERROR
int shutdown(int sock, int howto);
//SD_RECEIVE，断开输入流
//SD_SEND，断开输出流
//SD_BOTH，断开输入输出流

file_server_win.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>

#define BUF_SIZE 30
void ErrorHanding(char *message);

int main(int argc, char *argv[]) {
	WSADATA wsaData;
	SOCKET serv_sock;
	SOCKET clnt_sock;

	FILE *fp;
	char buf[BUF_SIZE];
	int read_cnt;

	SOCKADDR_IN serv_addr;
	SOCKADDR_IN clnt_addr;
	int addr_size;

	if(argc!=2) {
		printf("Usage : %s <port>\n", argv[0]);
		exit(1);
	}

	if(WSAStartup(MAKEWORD(2, 2), &wsaData)!=0)
		ErrorHanding("WSAStartup() error!");
		
	serv_sock = socket(PF_INET, SOCK_STREAM, 0);
	if(serv_sock==-1)
		error_handling("socket() error");

	addr_size = sizeof(SOCKADDR_IN);
	
	memset(&serv_addr, 0, serv_addr_size);
	serv_addr.sin_family = AF_INET;
	serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
	serv_addr.sin_port = htons(atoi(argv[1]));
	
	if(bind(serv_sock, (SOCKADDR*)&serv_addr, serv_addr_size)==SOCKET_ERROR)
		error_handling("bind() error");
		
	if(listen(serv_sock, 5)==SOCKET_ERROR)
		error_handling("listen() error");

	clnt_sock = accept(serv_sock, (SOCKADDR*)&clnt_addr, &addr_size);
	if(clnt_sock==INVALID_SOCKET)
		error_handling("accept() error");
		
	fp = fopen("file_serve_win.c", "rb");
	do {
		read_cnt = fread((void*)buf, 1, BUF_SIZE, fp);
		send(clnt_sock, buf, read_cnt, 0);
	} while(read_cnt==BUF_SIZE);
	fclose(fp);	
	//关闭输出流，不再向客户端发送数据
	shutdown(clnt_sock, SD_SEND);
	
	recv(clnt_sock, buf, BUF_SIZE, 0);
	printf("Message from client: %s\n", buf);

	close(clnt_sock);
	close(serv_sock);
	WSACleanup();
	return 0;
}

void ErrorHanding(char *message) {
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}

cl /EHsc file_server_win.c /Fe:fServerWin.exe /link ws2_32.lib
fServerWin 9190

file_client_win.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>

#define BUF_SIZE 30
void ErrorHanding(char *message);

int main(int argc, char *argv[]) {
	WSADATA wsaData;
	SOCKET sock;
	
	FILE *fp;
	char buf[BUF_SIZE];
	int read_cnt;

	SOCKADDR_IN addr;
	int addr_size;

	if(argc!=3) {
		printf("Usage : %s <IP> <port>\n", argv[0]);
		exit(1);
	}

	if(WSAStartup(MAKEWORD(2, 2), &wsaData)!=0)
		ErrorHanding("WSAStartup() error!");
		
	sock = socket(PF_INET, SOCK_STREAM, 0);
	if(sock==-1)
		ErrorHanding("socket() error");

	addr_size = sizeof(SOCKADDR_IN);
	memset(&addr, 0, addr_size);
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = inet_addr(argv[1]);
	addr.sin_port = htons(atoi(argv[2]));
	
	if(connect(sock, (SOCKADDR*)&addr, addr_size)==SOCKET_ERROR)
		ErrorHanding("connect() error");
		
	fp = fopen("receive.dat", "wb");
	while( (read_cnt = recv(sock, buf, BUF_SIZE, 0)) != 0 )
		fwrite((void*)buf, 1, read_cnt, fp);
	fclose(fp);
	
	puts("Received file data");
	send(sock, "Thank you", 10, 0);
	closesocket(sock);
	WSACleanup();
	return 0;
}

void ErrorHanding(char *message) {
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}

cl /EHsc file_client_win.c /Fe:fClientWin.exe /link ws2_32.lib
fClientWin 127.0.0.1 9190