server.c

一个在linux环境下的ftp的实现程序！

/*************************************
 * SOCKET 连接服务端程序             *
 * 将收到的报文原样返回              *
 ************************************/

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

#define DATALEN  500

int main(int argc, char **argv)
{
	FILE *fp;
	int iRecvLen,iRead;
        struct protoent *pProtoent;
        struct sockaddr_in sin,sAddrIn;
        int sid,isSid,sType,iAddrLen;
	char cConnectIp[17],cDataBuf[DATALEN+1],cRecvFile[80];

	if(argc!=3) {
		printf("Usage: %s 端口号 协议类型[1-UDP 0-TCP] \n",argv[0]);
		exit(-1);
	}

	/* 先配置参数 */
	memset(&sin,0,sizeof(sin));
        sin.sin_family=AF_INET;
        sin.sin_addr.s_addr=INADDR_ANY;
	if((sin.sin_port=htons((u_short)atoi(argv[1])))==0) {
		printf(" 开放端口有误 !\n");
		exit(-1);
	}

	if (atoi(argv[2]))  {
		if((pProtoent=getprotobyname("udp"))==0) {
			printf(" udp协议有误 !\n");
			exit(-1);
		}
                sType=SOCK_DGRAM;
	} else {
		if((pProtoent=getprotobyname("tcp"))==0) {
			printf(" tcp协议有误 !\n");
			exit(-1);
		}
                sType=SOCK_STREAM;
	}

	/* 建立 socket  */
        sid=socket(PF_INET,sType,pProtoent->p_proto);
	if(sid<0) {
		printf(" 建立socket失败!\n");
		exit(-1);
	}	
	
	printf(" socket建立成功!\n");
        if (bind(sid,(struct sockaddr *)&sin,sizeof(sin))<0) {
		printf(" 绑定失败!\n");
		exit(-1);
	}
	printf(" 绑定成功!\n");

	if(listen(sid,25) < 0) {
		printf(" 建立侦听失败!\n");
		exit(-1);
	}

        printf("Listening on port %s.......\n",argv[1]);

	while(1) {
		iAddrLen=sizeof(sAddrIn);
                if((isSid=accept(sid,(struct sockaddr *)&sAddrIn,&iAddrLen))<0) {
			printf("accept error !\n");
			sleep(2);
			continue;
		}
                memset(cConnectIp,0,sizeof(cConnectIp));
                strcpy(cConnectIp,inet_ntoa(sAddrIn.sin_addr));
		printf(" 收到 %s 的连接\n",cConnectIp);

		memset(cDataBuf,0x0,sizeof(cDataBuf));
		/* 先接收文件长度 */

		if(recv(isSid,cDataBuf,8,0) <0) {
			printf(" 报文长度接收失败 !\n");
			break;
		}
		iRecvLen = atoi(cDataBuf);

		sprintf(cRecvFile,"%s/tmp/test.txt",getenv("HOME"));
		if((fp=fopen(cRecvFile,"w"))==NULL) {
			printf("  打开接收文件错 !\n");
			break;
		}

		while(iRecvLen > 0) {
			iRead = recv(isSid,cDataBuf,1024,0);
			if(iRead < 0) {
				printf(" 数据报文接收失败 !\n");
				break;
			}
			iRecvLen -=iRead;
			fwrite(cDataBuf,iRead,1,fp);
		}
		fclose(fp);

		strcpy(cDataBuf,"文件接收完成");
		if(send(isSid,cDataBuf,strlen(cDataBuf),0)<0) {
			printf(" 数据报文发送失败 !\n");
			break;
		}
		printf("发送成功，等待接收.....\n");
		shutdown(isSid,2); close(isSid);
	}

	shutdown(isSid,2); close(isSid);
	shutdown(sid,2); close(sid);
	exit(0);

}