這裡是libcurl庫的一個簡單封裝，支援跨平臺。

宣告：

    本文章可以轉載，但必須註明源部落格地址。共享的demo和curltools類不允許個人上傳網路賺取積分和現金，如有發現必定追究責任，請慎重。

直接下載我上傳的資源把curl資料夾解壓到工程程式碼目錄下匯入curltools標頭檔案和原始檔到工程中，方可直接使用。

1、支援協議：http、https(短連線封裝模式)

2、支援ca證書

3、支援表單提交

4、支援ftp上傳/下載/遠端目錄列表獲取(長連線封裝模式)

5、支援STL string 字元全域性替換功能

http呼叫如圖：

FTP呼叫如圖：

FTP效果如圖：

標頭檔案：

#pragma once
#include <string>
#include <vector>
#include "include/curl.h"
#include "include/easy.h"
#pragma comment(lib,"curl/lib/libcurl.lib")

/************************************************************************/
/*           libcurl庫封裝    ssdwujianhua 2017年6月7日 13:17:11      */
/************************************************************************/

//表單key對應的型別
enum E_KEY_TYPE {
	e_key_text,			//文字型別
	e_key_iamge			//圖片型別
};

//表單資訊結構
typedef struct 
{
	std::string strKey;
	std::string strVal;
	E_KEY_TYPE eKeyType;

	void Set(std::string key, std::string val, E_KEY_TYPE eType)
	{
		strKey = key;
		strVal = val;
		eKeyType = eType;
	}
}POST_LIST, *LPPOST_LIST;


//表單資料
#define  _POST_LIST_DATA_ std::vector<POST_LIST>

class CTools
{
public:
	static std::string replace(const char *pszSrc, const char *pszOld, const char *pszNew);
	static const char * getAppPath();
};

class CUrlHttp
{
public:
	CUrlHttp(void);
	~CUrlHttp(void);
	static int Request(std::string strRequestType,
		std::string strUrl,
		std::string &strReport,		
		std::vector<std::string> vecHeader,
		std::string strParam="", 
		std::string strCookie="",  
		std::string strCaPath="",
		int nTimeOut=0);

	//有圖片建議使用表單提交比較方便
	static int RequestSSL(std::string strUrl,
		std::string &strReport,
		_POST_LIST_DATA_ listParam, 
		std::vector<std::string> vecHeader,
		std::string strCookie="",  
		std::string strCaPath="",
		int nTimeOut=0);
};

class CUrlFtp
{
public:
	CUrlFtp();
	~CUrlFtp();
	typedef struct 
	{
		size_t type;					//0:資料夾 1：檔案
		std::string name;				//名稱
		std::string permissions;		//許可權
	}FILE_INFO, *LPFILE_INFO;
	
public:
	int connect(const char *user, const char *password, const char * ip, short port=21);
	void close();
	int download(const char * remoteFile, const char * localFile, size_t timeOut=0);
	int upload(const char * remoteFile, const char * localFile, size_t timeOut=0);
	int dirlist(const char * remote, std::vector<FILE_INFO> &vecFileInfo);
	const char * getLastError();

private:
		CURL *curl;
		std::string m_ip;
		std::string m_user;
		std::string m_password;
		short m_port;
		std::string m_lastError;
};



 

原始檔：

#include "curltools.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#ifdef WIN32
#include <io.h>
#else
#include <unistd.h>
#endif

//引數文件地址：https://curl.haxx.se/libcurl/c/libcurl-tutorial.html

namespace _CURL_
{  
	/**
	* buf: 從伺服器返回的buffer
	* unit: buufer的單位
	* bufSize: buffer的大小
	* data: 儲存從伺服器返回的內容
	* 注意這個函式會被呼叫多次
	*/
	static size_t write_data(void *buf, size_t unit, size_t bufSize, std::string * data) 
	{
		int size = unit * bufSize;
		char * tmp = (char*)malloc(size + 1);
		memcpy(tmp, buf, size);
		tmp[size] = '\0';
		data->append(tmp);
		free(tmp);
		return size;
	}

	static size_t ftp_read(void *ptr, size_t size, size_t nmemb, void *stream)
	{
		curl_off_t nread;
		size_t retcode = fread(ptr, size, nmemb, (FILE *)stream);
		nread = (curl_off_t)retcode;
		return retcode;
	}

	//ftp 檔案結構
	typedef struct FtpFile 
	{
		char filename[512];					//檔名稱
		FILE *stream;						//檔案操作指標
	}FTP_FILE, *LPFTP_FILE;

	static size_t ftp_write(void *buffer, size_t size, size_t nmemb,void *stream)
	{
		struct FtpFile *out = (struct FtpFile *)stream;
		if(out && !out->stream) {
			out->stream = fopen(out->filename, "wb");
			if(!out->stream)
				return -1; 
		}
		return fwrite(buffer, size, nmemb, out->stream);
	}




	//智慧初始化curl庫和釋放curl庫
	class CurlIntelligence
	{
	public:
		CurlIntelligence()
		{
			curl_global_init(CURL_GLOBAL_ALL);
		}

		~CurlIntelligence()
		{
			curl_global_cleanup();
		}
	};
}

_CURL_::CurlIntelligence g_curl;

/*
 *	函式：
 *		 replace（替換字串）
 *  引數：
 *		pszSrc：源字串
 *		pszOld：需要替換的字串
 *		pszNew：新字串
 *  返回值：
 *		返回替換後的字串
 * ssdwujianhua 2017/12/04 
 */
std::string CTools::replace(const char *pszSrc, const char *pszOld, const char *pszNew)  
{  
    std::string strContent, strTemp;  
    strContent.assign( pszSrc );  
    std::string::size_type nPos = 0;  
    while( true )  
    {  
        nPos = strContent.find(pszOld, nPos);  
		if ( nPos == std::string::npos )  
		{  
			break;  
		}  
        strTemp = strContent.substr(nPos+strlen(pszOld), strContent.length());  
        strContent.replace(nPos,strContent.length(), pszNew );  
        strContent.append(strTemp);  
        nPos +=strlen(pszNew) - strlen(pszOld)+1; //防止重複替換 避免死迴圈  
    }  
    return strContent;  
} 

const char * CTools::getAppPath()
{
	static std::string appPath;
	if ( appPath.empty() )
	{
		char szBuf[1024];
		memset(szBuf, '\0', 1024);
#ifdef _WIN32
		GetModuleFileName(NULL, szBuf, 1024);
		std::string temp = szBuf;
		std::string::size_type pos = temp.find_last_of("\\")+1;
		appPath = temp.substr(0, pos);
#else
		getcwd(szBuf, 1024);
		appPath.assign(szBuf);
		appPath.append("/");
#endif
	}
	return appPath.c_str();
}



CUrlHttp::CUrlHttp(void)
{
}

CUrlHttp::~CUrlHttp(void)
{
}

/*
 *	函式：
 *		 Request（請求函式）
 *  引數：
 *		strRequestType：請求型別（get，post）
 *		strUrl:請求url地址
 *		strReport：回執資訊
 *		strHeader:請求頭
 *		strCookie：cookie資訊
 *		strCaPath：ca轉成pem證書路徑
 *		strParam：請求引數（get的時候此引數填空）
 *		nTimeOut:超時設定預設是0秒 是無限等待
 *  返回值：
 *		0表示成功 非0表示錯誤程式碼
 * ssdwujianhua 2017/06/06 
 */
int CUrlHttp::Request(std::string strRequestType, 
					  std::string strUrl, 
					  std::string &strReport, 
					  std::vector<std::string> vecHeader, 
					  std::string strParam/* ="" */, 
					  std::string strCookie/* ="" */, 
					  std::string strCaPath/* ="" */, 
					  int nTimeOut/* =0 */)
{
	CURL * curl;
	curl = curl_easy_init();
	curl_easy_setopt(curl, CURLOPT_URL, strUrl.c_str());
	
	if ( strRequestType.compare("post")==0 || strRequestType.compare("POST") == 0 )
	{
		curl_easy_setopt(curl, CURLOPT_POST, 1);
		curl_easy_setopt(curl, CURLOPT_POSTFIELDS, strParam.c_str());
	}
	else
	{
		curl_easy_setopt(curl, CURLOPT_POST, 0);//get請求
	}

	//設定http頭
	curl_slist * headers = NULL;
	for ( int i=0; i<vecHeader.size(); i++ )
	{
		if (!vecHeader.at(i).empty())
		{
			headers = curl_slist_append(headers, vecHeader.at(i).c_str());
		}
	}
	if (headers != NULL)
	{
		curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
	}

	//判斷是否有證書
	if(strCaPath.empty())
	{
		curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, false);
		curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, false);
	}
	else
	{
		//預設情況就是PEM，所以無需設定，另外支援DER
		//curl_easy_setopt(curl,CURLOPT_SSLCERTTYPE,"PEM");
		curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, true);
		curl_easy_setopt(curl, CURLOPT_CAINFO, strCaPath.c_str());
	}

	std::string strReportHeader;//回執回來的頭資料
	curl_easy_setopt(curl, CURLOPT_VERBOSE, 1);		//可以看到除錯資訊
	//接受伺服器的ssl證書而不管合不合法 （相當於命令列中的--insecure）
	curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
	curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
	//curl_easy_setopt(curl,CURLOPT_HEADERFUNCTION,_CURL_::write_data);
	//curl_easy_setopt(curl, CURLOPT_WRITEHEADER, &strReportHeader);
	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, _CURL_::write_data);
	curl_easy_setopt(curl, CURLOPT_WRITEDATA, &strReport); 
	if ( nTimeOut > 0  )
	{
		curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, nTimeOut);
		curl_easy_setopt(curl, CURLOPT_TIMEOUT, nTimeOut);
	}
	
	
	

	if (!strCookie.empty())
	{

		curl_easy_setopt(curl, CURLOPT_COOKIEFILE, strCookie.c_str());
	}
	CURLcode code = curl_easy_perform(curl);
	if ( headers != NULL )
	{
		curl_slist_free_all(headers);
	}
	curl_easy_cleanup(curl);
	//打印出來
// 	std::string strReportData;
// 	strReportData.append(strReportHeader);
// 	strReportData.append(strReport);
// 	TRACE("request:%s  url:%s report:%s", strRequestType.c_str(), strUrl.c_str(), strReportData.c_str());
	return code;
}

/*
 *	函式：
 *		 RequestSSL（表單提交）
 *  引數：
 *		strUrl:請求url地址
 *		strReport：回執資訊
 *		vecHeader:請求頭
 *		strCookie：cookie資訊
 *		listParam：表單列表
 *		strCaPath：ca轉成pem證書路徑
 *		nTimeOut:超時設定預設是0秒 是無限等待：
 *  返回值：
 *		0表示成功 非0表示錯誤程式碼
 * ssdwujianhua 2017/07/21 
 */
int CUrlHttp::RequestSSL(std::string strUrl, 
						 std::string &strReport, 
						 _POST_LIST_DATA_ listParam, 
						 std::vector<std::string> vecHeader,
						 std::string strCookie/* ="" */, 
						 std::string strCaPath/* ="" */, 
						 int nTimeOut/* =0 */)
{
	CURLcode code;
	CURL * curl;
	curl = curl_easy_init();
	curl_easy_setopt(curl, CURLOPT_POST, 1);
	curl_easy_setopt(curl, CURLOPT_URL, strUrl.c_str());  
	//err = curl_easy_setopt(hCurl, CURLOPT_HTTPHEADER, "dfsdf");   
	//設定http頭
	curl_slist * headers = NULL;
	for ( int i=0; i<vecHeader.size(); i++ )
	{
		if (!vecHeader.at(i).empty())
		{
			headers = curl_slist_append(headers, vecHeader.at(i).c_str());
		}
	}
	if (headers != NULL)
	{
		curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
	}


	struct curl_httppost *post=NULL;        
	struct curl_httppost *last=NULL;      

	CURLFORMcode errf; 
	for ( int i=0; i<listParam.size(); i++ )
	{
		POST_LIST post_list = listParam.at(i);
		if (post_list.eKeyType == e_key_iamge ) //圖片型別 直接提交圖片路徑
		{
			errf = curl_formadd(&post, &last,   CURLFORM_COPYNAME, post_list.strKey.c_str(),   
				CURLFORM_FILE,post_list.strVal.c_str(),CURLFORM_CONTENTTYPE, "image/jpeg",CURLFORM_END);
		}
		else
		{
			errf = curl_formadd(&post, &last,  CURLFORM_COPYNAME, post_list.strKey.c_str(),   
				CURLFORM_COPYCONTENTS, post_list.strVal.c_str(),CURLFORM_END); 
		}


	}
	

	curl_easy_setopt(curl, CURLOPT_READFUNCTION, NULL);        
	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, _CURL_::write_data);       
	curl_easy_setopt(curl, CURLOPT_WRITEDATA, &strReport);         
	curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1); 

	//判斷是否有證書
	if(strCaPath.empty())
	{
		curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, false);
		curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, false);
	}
	else
	{
		//預設情況就是PEM，所以無需設定，另外支援DER
		//curl_easy_setopt(curl,CURLOPT_SSLCERTTYPE,"PEM");
		curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, true);
		curl_easy_setopt(curl, CURLOPT_CAINFO, strCaPath.c_str());
	}

	//設定超時時間
	if ( nTimeOut > 0  )
	{
		curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, nTimeOut);
		curl_easy_setopt(curl, CURLOPT_TIMEOUT, nTimeOut);
	}       
	curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION,1); //是否抓取跳轉後的頁面       
	/* Set the form info */          
	curl_easy_setopt(curl, CURLOPT_HTTPPOST, post);    //  
	curl_easy_setopt(curl, CURLOPT_HEADER, 0);  //不讀取返回頭的資料

	
	

	//設定http cookie
	if (!strCookie.empty())
	{
		curl_easy_setopt(curl, CURLOPT_COOKIEFILE, strCookie.c_str());
	}
	code = curl_easy_perform(curl); /* post away! */       
	//獲取請求返回的值  如：200
	//code = curl_easy_getinfo(curl,CURLINFO_RESPONSE_CODE, &RESPONSE_CODE);
	/* free the post data again */
	if ( headers != NULL )
	{
		curl_slist_free_all(headers);
	}
	curl_formfree(post);            
	curl_easy_cleanup(curl);
	return code;
}


 

/********************************************************************************************
*									curl FTP 類封裝											*	
*
*
*********************************************************************************************/
CUrlFtp::CUrlFtp()
{
	curl = NULL;
}

CUrlFtp::~CUrlFtp()
{
	close();
}

/*
 *	函式：
 *		 connect（ftp連線）
 *  引數：
 *		user：ftp帳號
 *		password：ftp密碼
 *		ip：ftpip
 *		port：ftp埠
 *  返回值：
 *		成功返回0 失敗返回-1
 * ssdwujianhua 2017/12/29 
 */
int CUrlFtp::connect( const char *user, const char *password, const char * ip, short port /*=21*/)
{
	curl = curl_easy_init();
	if ( curl == NULL )
	{
		m_lastError.assign("curl initialization failure!");
		printf("curl initialization failure!\n");
		return -1;
	}

	//設定登入帳號和密碼
	std::string spider;
	spider.append(user);
	spider.append(":");
	spider.append(password);
	curl_easy_setopt(curl, CURLOPT_USERPWD, spider.c_str());

	std::string url;
	url.append("ftp://");;
	url.append(ip);
	if ( port != 0  )
	{
		url.append(":");
		char szPort[10];
		sprintf(szPort, "%d", port);
		url.append(szPort);
	}
	curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
	curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);

	CURLcode code = curl_easy_perform(curl);
	if ( code != CURLE_OK )
	{
		m_lastError = curl_easy_strerror( code );
		printf("ftp connect failure: %s!\n", m_lastError.c_str());
		close();
		return -1;
	}
	m_ip.assign(ip);
	m_user.assign(user);
	m_password.assign(password);
	m_port = port;
	m_lastError.assign("ftp connect success!");
	printf("ftp connect success!\n");
	return 0;
}

/*
 *	函式：
 *		 close（ftp關閉）
 *  引數：
 *		無
 *  返回值：
 *		無
 * ssdwujianhua 2017/12/29 
 */
void CUrlFtp::close()
{
	if ( curl != NULL )
	{
		curl_easy_cleanup(curl);
		curl = NULL;
	}
}

/*
 *	函式：
 *		 download（ftp檔案下載）
 *  引數：
 *		remoteFile：遠端檔案路徑
 *		localFile：本地檔案路徑
 *		timeOut：超時時間 單位秒
 *  返回值：
 *		成功返回0 失敗返回-1
 * ssdwujianhua 2017/12/29 
 */
int CUrlFtp::download(const char * remoteFile, const char * localFile, size_t timeOut /*= 0*/)
{
	if ( curl == NULL )
	{
		m_lastError.assign("ftp disconnect!");
		printf("ftp disconnect!");
		return -1;
	}
	std::string newRemotePath = CTools::replace(remoteFile, "\\", "/" );
	std::string newLocalPath = CTools::replace(localFile, "\\", "/" );
	_CURL_::FTP_FILE ftpfile;
	sprintf(ftpfile.filename, "%s",newLocalPath.c_str());
	ftpfile.stream = NULL;
	std::string url;
	url.append("ftp://");;
	url.append(m_ip);
	url.append(":");
	char szPort[10];
	sprintf(szPort, "%d", m_port);
	url.append(szPort);
	url.append("/");
	url.append(newRemotePath);
	curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, _CURL_::ftp_write);
	curl_easy_setopt(curl, CURLOPT_WRITEDATA, &ftpfile);
	curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
	if ( timeOut > 0 )
	{
		curl_easy_setopt(curl, CURLOPT_FTP_RESPONSE_TIMEOUT, timeOut);
	}
	CURLcode code = curl_easy_perform(curl);
	if ( code != CURLE_OK )
	{
		m_lastError = curl_easy_strerror( code );
		printf("ftp download failure: %s!\n", m_lastError.c_str());
		return -1;
	}
	if (ftpfile.stream != NULL )
	{
		fclose(ftpfile.stream);
		ftpfile.stream = NULL;
	}
	m_lastError.assign("ftp upload success!");
	return 0;
}

/*
 *	函式：
 *		 upload（ftp檔案上傳）
 *  引數：
 *		remoteFile：遠端檔案路徑
 *		localFile：本地檔案路徑
 *		timeOut：超時時間 單位秒
 *  返回值：
 *		成功返回0 失敗返回-1
 * ssdwujianhua 2017/12/29 
 */
int CUrlFtp::upload(const char * remoteFile, const char * localFile, size_t timeOut/*=0*/)
{
	if ( curl == NULL )
	{
		m_lastError.assign("ftp disconnect!");
		printf("ftp disconnect!");
		return -1;
	}
	std::string newRemotePath = CTools::replace(remoteFile, "\\", "/" );
	std::string newLocalPath = CTools::replace(localFile, "\\", "/" );

	CURLcode code;
	FILE *hd_src;
	struct stat file_info;
	curl_off_t fsize;

	std::size_t nItem = newRemotePath.find_last_of("/");
	std::string remoteFileName = newRemotePath.substr(nItem+1);//檔名稱
	std::string remotePath = newRemotePath.substr(0, nItem);//遠端路徑

	struct curl_slist *headerlist = NULL;
	char buf_1 [256] = "RNFR while-uploading";
	char buf_2 [256];	//遠端檔名稱
	sprintf(buf_2,"RNTO %s", remoteFileName.c_str());
	if(stat(newLocalPath.c_str(), &file_info)) 
	{
		m_lastError.assign("the uploaded file does not exist!");
		printf("the uploaded file does not exist(%s)!\n", localFile);
		return -1;
	}
	fsize = (curl_off_t)file_info.st_size;
	hd_src = fopen(newLocalPath.c_str(), "rb");
	if ( hd_src == NULL )
	{
		m_lastError.assign("file open failed!");
		printf("file open failed(%s)!\n", localFile);
		return -1;
	}
	
	headerlist = curl_slist_append(headerlist, buf_1);
	headerlist = curl_slist_append(headerlist, buf_2);
	curl_easy_setopt(curl, CURLOPT_READFUNCTION, _CURL_::ftp_read);
	curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
	//設定ftp url
	std::string url = "ftp://";
	url.append(m_ip);
	url.append(":");
	char szPort[10];
	sprintf(szPort, "%d", m_port);
	url.append(szPort);
	url.append("/");
	url.append(remotePath);
	url.append("/");
	url.append("while-uploading");
 	curl_easy_setopt(curl, CURLOPT_URL, url.c_str());  
	curl_easy_setopt(curl, CURLOPT_POSTQUOTE, headerlist);
	curl_easy_setopt(curl, CURLOPT_READDATA, hd_src);
	curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE,(curl_off_t)fsize);

	if ( timeOut > 0 )
	{
		curl_easy_setopt(curl, CURLOPT_FTP_RESPONSE_TIMEOUT, timeOut);
	}
	code = curl_easy_perform(curl);
	curl_slist_free_all(headerlist);
	if ( code != CURLE_OK )
	{
		fclose(hd_src);
		m_lastError = curl_easy_strerror( code );
		printf("ftp upload failure: %s!\n", m_lastError.c_str());
		return -1;
	}
	fclose(hd_src); 
	m_lastError.assign("ftp upload success!");
	return code;
}

/*
 *	函式：
 *		 dirlist（遠端目錄列表獲取）
 *  引數：
 *		remote：遠端目錄路徑
 *		vecFileInfo：輸出遍歷得到的資料夾和檔案
 *  返回值：
 *		成功返回0 失敗返回-1
 * ssdwujianhua 2017/12/29 
 */
int CUrlFtp::dirlist(const char * remote, std::vector<FILE_INFO> &vecFileInfo)
{
	if ( curl == NULL )
	{
		m_lastError.assign("ftp disconnect!");
		printf("ftp disconnect!");
		return -1;
	}
	std::string remotePath = CTools::replace(remote, "\\", "/" );
	if ( remotePath.size() == 0 )
	{
		remotePath.append("/");
	}
	if ( remotePath[remotePath.length()-1] != '/')
	{
		remotePath.append("/");
	}
	std::string url;
	url.append("ftp://");;
	url.append(m_ip);
	url.append(":");
	char szPort[10];
	sprintf(szPort, "%d", m_port);
	url.append(szPort);
	url.append("/");
	url.append(remotePath);
	std::string response;
	curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
	curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, _CURL_::write_data);       
	curl_easy_setopt(curl, CURLOPT_WRITEDATA, &response); 
	CURLcode code = curl_easy_perform(curl);
	if ( code != CURLE_OK )
	{
		m_lastError = curl_easy_strerror( code );
		printf("ftp connect failure: %s!\n", m_lastError.c_str());
		return -1;
	}
	//解析ftp資料得到檔案和資料夾屬性
	std::string::size_type pos=0, index=0, len=0;
	while( true )  
	{  
		std::string row= "";
		pos = response.find("\r\n", pos)+2;
		if ( pos < index )  
		{  
			break;  
		}  
		len =  pos - index;//需要擷取的字串長度
 		row = response.substr(index, len); //得到每行資料
		index = pos;

		std::string::size_type rowPos=0, rowIndex=0, rowLen=0;
		//得到名稱
		FILE_INFO fileInfo;
		rowPos = row.find_last_of(' ')+1; 
		std::string name = row.substr(rowPos, row.length());
		if ( name.size() == 0 || name[0] == '.')
		{
			continue;
		}
		
		fileInfo.name = name;
		//得到檔案許可權和檔案型別
		rowPos = row.find_first_of(' ');
		std::string data = row.substr(0,rowPos);
		if ( data.size() != 0 )
		{
			if (data[0] == 'd')
			{
				//資料夾
				fileInfo.type = 0;
				fileInfo.permissions = data.substr(1, data.length());
			}
			else 
			{
				//檔案
				fileInfo.type = 1;
				fileInfo.permissions = data.substr(1, data.length());
			}
			
		}

		vecFileInfo.push_back(fileInfo);
	}  
	m_lastError.assign("");
	return 0;
}

/*
 *	函式：
 *		 getLastError（最後錯誤資訊）
 *  引數：
 *		無
 *  返回值：
 *		對應的錯誤資訊
 * ssdwujianhua 2017/12/29 
 */
const char * CUrlFtp::getLastError()
{
	return m_lastError.c_str();
}