CURL 庫在使用FTP傳輸檔案時， 正常情況下， ftp的server端都會預設進入根目錄 /,   但是當ftp的server端設定了一個子目錄，

比如 ftp的server設定了  /data/movies 為第一次預設進入的目錄， 則curl的FTP將會無法傳輸檔案， 錯誤的原因是 ：

而第一次進入的目錄為 /data/movies  ， 而curl庫的FTP解析ftp地址得出 要進入 data 和movies 目錄後才能找到下載的檔案，

就會去執行  CWD data   和  CWD movies ， 而在 /data/movies 這個目錄去進入  data 目錄， 目錄肯定是不存在的，

所以出錯。

具體的錯誤現象如下：

* About to connect() to 192.168.2.223 port 21 (#0) * Trying 192.168.2.223... Leave Lock = Resume Download File * connected * Connected to 192.168.2.223 (192.168.2.223) port 21 (#0) < 220 (vsFTPd 2.0.5) > USER root < 331 Please specify the password. > PASS 123456 < 230 Login successful. > PWD < 257 "/data/movies" * Entry path is '/data/movies' > CWD data < 550 Failed to change directory. * Server denied you to change to the given directory * Connection #0 to host 192.168.2.223 left intact * Access denied to remote resource > QUIT < 221 Goodbye. * Closing connection #0

下面的程式碼是我使用的程式碼

void dispatch_threadpool_to_me(void *arg) { MissionInfo* pMission = (MissionInfo*)arg; uint64 filelen = 0; int tries = 0; CURL *curlhandle; RE_Download: FILE *fp; curl_off_t local_file_len = -1 ; uint64 filesize =0 ; CURLcode result = CURLE_GOT_NOTHING; #ifdef _WIN32 struct _stat file_info; #else struct stat file_info; #endif int use_resume = 0; /* 得到本地檔案大小 */ if(stat(pMission->localPath, &file_info) == 0) { int flen = file_info.st_size; if (flen%DOWNLOAD_FILE_SEGMENT == 0) { //assert (flen > 0); local_file_len = flen - DOWNLOAD_FILE_SEGMENT; } else { local_file_len = flen - flen%DOWNLOAD_FILE_SEGMENT - DOWNLOAD_FILE_SEGMENT; } local_file_len = (local_file_len > 0) ? local_file_len : 0; assert (local_file_len%DOWNLOAD_FILE_SEGMENT == 0); use_resume = 1; } if (pMission->missionType == MISSION_TYPE_REMOVEFILE) { //刪除任務 if (use_resume == 0) { writelog(LOG_ERROR, "remove file is not exists, path=%s/n", pMission->localPath); } unlink(pMission->localPath); (*pMission->downcbfunc)(pMission->missionID, pMission->missionType, pMission->epgID, 0, "removeFileSuccess", pMission->localPath, 0); return; } curlhandle = curl_easy_init(); if(curlhandle == NULL) return ; //採用追加方式開啟檔案，便於實現檔案斷點續傳工作 fp = fopen(pMission->localPath, "ab+"); //ftp伺服器可能無法斷點續傳,所以不能追加寫 //fp = fopen(pMission->localPath, "w"); if (fp == NULL) { curl_easy_cleanup(curlhandle); writelog(LOG_ERROR, "Download fopen file Error , file=%s/n", pMission->localPath); return ; } curl_easy_setopt(curlhandle, CURLOPT_URL, pMission->remotePath); curl_easy_setopt(curlhandle, CURLOPT_CONNECTTIMEOUT, 60); // 設定連線超時，單位秒 curl_easy_setopt(curlhandle, CURLOPT_TIMEOUT, 1800); //設定http 頭部處理函式 curl_easy_setopt(curlhandle, CURLOPT_HEADERFUNCTION, GetContentLengthFunc); curl_easy_setopt(curlhandle, CURLOPT_HEADERDATA, &filesize); // 設定檔案續傳的位置給libcurl //use_resume = 0; //伺服器不支援斷點續傳的時候無法續傳，所以強制從頭開始下載檔案 curl_easy_setopt(curlhandle, CURLOPT_RESUME_FROM_LARGE, use_resume?local_file_len:0); curl_easy_setopt(curlhandle, CURLOPT_WRITEDATA, fp); curl_easy_setopt(curlhandle, CURLOPT_WRITEFUNCTION, wirtefunc); curl_easy_setopt(curlhandle, CURLOPT_FTP_USE_EPSV, 0); //EPSV設定為0,就代表啟用PASV curl_easy_setopt(curlhandle, CURLOPT_NOPROGRESS, 1L); #ifdef _DEBUG curl_easy_setopt(curlhandle, CURLOPT_VERBOSE, 1L); #endif result = curl_easy_perform(curlhandle); curl_easy_cleanup(curlhandle); if (result == CURLE_OK) { fseek(fp, 0, SEEK_END); filelen = ftell(fp); fclose(fp); writelog(LOG_ERROR, "Success Download File local = %s, remote = %s/n", pMission->localPath, pMission->remotePath); char buffer[512]={0}; if (CompareMD5 (pMission->localPath)) { const char* p = g_Config.pukkaIndex; if (*p == '.' || *p == '/') SNPRINTF (buffer, sizeof(buffer)-1, "%s %s", g_Config.pukkaIndex, pMission->localPath); else SNPRINTF (buffer, sizeof(buffer)-1, "./%s %s", g_Config.pukkaIndex, pMission->localPath); system (buffer); (*pMission->downcbfunc)(pMission->missionID, pMission->missionType, pMission->epgID, 0, "ok", pMission->localPath, filelen); return ; } else { } } else if (result == CURLE_OPERATION_TIMEOUTED) { fclose(fp); writelog(LOG_ERROR, "down operation timeout/n"); goto RE_Download; } else if (result == CURLE_COULDNT_CONNECT) { writelog(LOG_ERROR, "Can not Connect FTP File local = %s, remote = %s/n", pMission->localPath, pMission->remotePath); (*pMission->downcbfunc)(pMission->missionID, pMission->missionType, pMission->epgID, -1, curl_easy_strerror(result), pMission->localPath, filelen); return ; } else { fclose(fp); tries ++; if (tries < MAX_TRY_DOWNLOAD_COUNT) { //writelog(LOG_ERROR, "Download File Try = %d /n localdir = %s /n remotedir = %s /n err=%s/n", // tries, pMission->localPath, pMission->remotePath, curl_easy_strerror(result)); sleep(MAX_SLEEP_TIME); if (result == CURLE_BAD_DOWNLOAD_RESUME) { unlink(pMission->localPath);//不能斷點續傳下載，則刪除本地已經下載的部分檔案 } goto RE_Download; } else if (tries == MAX_TRY_DOWNLOAD_COUNT) {//萬一ftp的伺服器不支援斷點續傳，所以重新把檔案刪除， 在下載一次 tries++; unlink(pMission->localPath); goto RE_Download; } else { writelog(LOG_ERROR, "Fail Download File local = %s, remote = %s/n", pMission->localPath, pMission->remotePath); (*pMission->downcbfunc)(pMission->missionID, pMission->missionType, pMission->epgID, -1, curl_easy_strerror(result), pMission->localPath, filelen); return ; } } }

修改方法是  修改 curl庫目錄下面 lib資料夾下面的 ftp.c 檔案

在函式 static CURLcode ftp_parse_url_path(struct connectdata *conn) 中 新增如下程式碼

if (ftpc->dirdepth == 0) { ftpc->dirs[0] = strdup("/"); ftpc->dirdepth++; }

意思就是 讓ftp客戶端從 根目錄開始一級一級的進入到檔案所在的目錄。

新增的位置如下 ：

default: /* allow pretty much anything */ case FTPFILE_MULTICWD: ftpc->dirdepth = 0; ftpc->diralloc = 5; /* default dir depth to allocate */ ftpc->dirs = calloc(ftpc->diralloc, sizeof(ftpc->dirs[0])); if(!ftpc->dirs) return CURLE_OUT_OF_MEMORY; /* we have a special case for listing the root dir only */ if(strequal(path_to_use, "/")) { cur_pos++; /* make it point to the zero byte */ ftpc->dirs[0] = strdup("/"); ftpc->dirdepth++; } else { /* parse the URL path into separate path components */ while((slash_pos = strchr(cur_pos, '/')) != NULL) { /* 1 or 0 pointer offset to indicate absolute directory */ ssize_t absolute_dir = ((cur_pos - data->state.path > 0) && (ftpc->dirdepth == 0))?1:0; if (ftpc->dirdepth == 0) { ftpc->dirs[0] = strdup("/"); ftpc->dirdepth++; } /* seek out the next path component */ if(slash_pos-cur_pos) { /* we skip empty path components, like "x//y" since the FTP command CWD requires a parameter and a non-existant parameter a) doesn't work on many servers and b) has no effect on the others. */ int len = (int)(slash_pos - cur_pos + absolute_dir); ftpc->dirs[ftpc->dirdepth] = curl_easy_unescape(conn->data, cur_pos - absolute_dir, len, NULL); if(!ftpc->dirs[ftpc->dirdepth]) { /* run out of memory ... */ failf(data, "no memory"); freedirs(ftpc); return CURLE_OUT_OF_MEMORY; } if(isBadFtpString(ftpc->dirs[ftpc->dirdepth])) { free(ftpc->dirs[ftpc->dirdepth]); freedirs(ftpc); return CURLE_URL_MALFORMAT; } } else { cur_pos = slash_pos + 1; /* jump to the rest of the string */ continue; } cur_pos = slash_pos + 1; /* jump to the rest of the string */ if(++ftpc->dirdepth >= ftpc->diralloc) { /* enlarge array */ char *bigger; ftpc->diralloc *= 2; /* double the size each time */ bigger = realloc(ftpc->dirs, ftpc->diralloc * sizeof(ftpc->dirs[0])); if(!bigger) { freedirs(ftpc); return CURLE_OUT_OF_MEMORY; } ftpc->dirs = (char **)bigger; } } } filename = cur_pos; /* the rest is the file name */ break; } /* switch */