client.c

一个在linux环境下的ftp的实现程序！

/*************************************
 * SOCKET 连接:客户端程序             *
 * 短连接方式                        *
 ************************************/
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#define DATALEN  500

int main(int argc, char *argv[])
{
	struct sockaddr_in sin;
	struct protoent *pProtoent;
	FILE *fp;
	char cDataBuf[DATALEN+1],cFile[50];
	int sid,iType,iReadLen,iSendLen,iFirst,iFileSize;

	if(argc!=4) {
		printf("Usage: %s IP地址 端口号 协议类型[1-UDP 0-TCP]\n",argv[0]);
		exit(-1);
	}

	/* 参数配置 */
	memset(&sin,0,sizeof(sin));
	sin.sin_family=AF_INET;
	if((sin.sin_addr.s_addr=inet_addr(argv[1]))==INADDR_NONE) {
		printf(" IP格式转换错误 \n");
		exit(-1);
	}
	if((sin.sin_port=htons((u_short)atoi(argv[2])))==0) {
		printf(" 端口格式转换错误 \n");
		exit(-1);
	}

	if (atoi(argv[3]))  {
		if ((pProtoent=getprotobyname("udp"))==0) {
			printf(" udp协议处理错误 \n");
			exit(-1);
		}
		iType=SOCK_DGRAM;
	} else {
		if ((pProtoent=getprotobyname("tcp"))==0) {
			printf(" tcp协议处理错误 \n");
			exit(-1);
		}
		iType=SOCK_STREAM;
	}


	if((sid=socket(AF_INET,iType,pProtoent->p_proto)) < 0) {
		printf(" socket 建立错误，请确定服务端进程已启动!\n");
		exit(-1);
	}

	printf(" socket 建立成功! \n" );

	/* 下面开始处理和服务端的消息传递 */
	if(connect(sid,(struct sockaddr *)&sin,sizeof(sin))<0) {
		printf(" 连接失败 !\n");
		exit(-1);
	}

	/* 发送数据报文 */
	sprintf(cFile,"%s/dbase/test.txt",getenv("HOME"));
	if(( fp=fopen(cFile,"r"))==NULL ) {
		printf(" 打开文件:%s 失败\n",cFile);
		exit(-1);
	}	
	fseek(fp,0,SEEK_END);
	iFileSize = ftell(fp);
	fseek(fp,0,SEEK_SET);

	iFirst = iReadLen =0;
	while(iFileSize>0) {
		memset(cDataBuf,0x0,sizeof(cDataBuf));
		if(iFirst==0) {  /* 第一个包说明文件长度*/
			sprintf(cDataBuf,"%08ld",iFileSize);
			iSendLen = 8;
			iFirst = 1;
		} else {
			iReadLen=fread(cDataBuf,1,1024,fp);
			iSendLen = iReadLen;
		}

		if(send(sid,cDataBuf,iSendLen,0)<0) {
			printf(" 数据报文发送失败 !\n");
			break;
		}
		iFileSize -=iSendLen;
	}
	fclose(fp);
	printf("发送成功，等待接收.....\n");
	/* 接收报文 */
	memset(cDataBuf,0x0,sizeof(cDataBuf));
	if(recv(sid,cDataBuf,DATALEN,0) <0) {
		printf(" 数据报文接收失败 !\n");
		exit(-1);
	}
	printf("收到的报文: %s\n",cDataBuf);

	shutdown(sid,0);
	close(sid);
	exit(0);
}