text: /* Arduino SdFat Library
   * Copyright (C) 2009 by William Greiman
   *
   * This file is part of the Arduino SdFat Library
   *
   * This Library is free software: you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or
   * (at your option) any later version.
   *
   * This Library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with the Arduino SdFat Library.  If not, see
   * <http://www.gnu.org/licenses/>.
   */
  
  #include "Marlin.h"
  #ifdef SDSUPPORT
  
  #include "SdBaseFile.h"
  //------------------------------------------------------------------------------
  // pointer to cwd directory
  SdBaseFile* SdBaseFile::cwd_ = 0;
  // callback function for date/time
  void (*SdBaseFile::dateTime_)(uint16_t* date, uint16_t* time) = 0;
  //------------------------------------------------------------------------------
  // add a cluster to a file
  bool SdBaseFile::addCluster() {
    if (!vol_->allocContiguous(1, &curCluster_)) goto fail;
  
    // if first cluster of file link to directory entry
    if (firstCluster_ == 0) {
      firstCluster_ = curCluster_;
      flags_ |= F_FILE_DIR_DIRTY;
    }
    return true;
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  // Add a cluster to a directory file and zero the cluster.
  // return with first block of cluster in the cache
  bool SdBaseFile::addDirCluster() {
    uint32_t block;
    // max folder size
    if (fileSize_/sizeof(dir_t) >= 0XFFFF) goto fail;
  
    if (!addCluster()) goto fail;
    if (!vol_->cacheFlush()) goto fail;
  
    block = vol_->clusterStartBlock(curCluster_);
  
    // set cache to first block of cluster
    vol_->cacheSetBlockNumber(block, true);
  
    // zero first block of cluster
    memset(vol_->cacheBuffer_.data, 0, 512);
  
    // zero rest of cluster
    for (uint8_t i = 1; i < vol_->blocksPerCluster_; i++) {
      if (!vol_->writeBlock(block + i, vol_->cacheBuffer_.data)) goto fail;
    }
    // Increase directory file size by cluster size
    fileSize_ += 512UL << vol_->clusterSizeShift_;
    return true;
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  // cache a file's directory entry
  // return pointer to cached entry or null for failure
  dir_t* SdBaseFile::cacheDirEntry(uint8_t action) {
    if (!vol_->cacheRawBlock(dirBlock_, action)) goto fail;
    return vol_->cache()->dir + dirIndex_;
  
   fail:
    return 0;
  }
  //------------------------------------------------------------------------------
  /** Close a file and force cached data and directory information
   *  to be written to the storage device.
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   * Reasons for failure include no file is open or an I/O error.
   */
  bool SdBaseFile::close() {
    bool rtn = sync();
    type_ = FAT_FILE_TYPE_CLOSED;
    return rtn;
  }
  //------------------------------------------------------------------------------
  /** Check for contiguous file and return its raw block range.
   *
   * \param[out] bgnBlock the first block address for the file.
   * \param[out] endBlock the last  block address for the file.
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   * Reasons for failure include file is not contiguous, file has zero length
   * or an I/O error occurred.
   */
  bool SdBaseFile::contiguousRange(uint32_t* bgnBlock, uint32_t* endBlock) {
    // error if no blocks
    if (firstCluster_ == 0) goto fail;
  
    for (uint32_t c = firstCluster_; ; c++) {
      uint32_t next;
      if (!vol_->fatGet(c, &next)) goto fail;
  
      // check for contiguous
      if (next != (c + 1)) {
        // error if not end of chain
        if (!vol_->isEOC(next)) goto fail;
        *bgnBlock = vol_->clusterStartBlock(firstCluster_);
        *endBlock = vol_->clusterStartBlock(c)
                    + vol_->blocksPerCluster_ - 1;
        return true;
      }
    }
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  /** Create and open a new contiguous file of a specified size.
   *
   * \note This function only supports short DOS 8.3 names.
   * See open() for more information.
   *
   * \param[in] dirFile The directory where the file will be created.
   * \param[in] path A path with a valid DOS 8.3 file name.
   * \param[in] size The desired file size.
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   * Reasons for failure include \a path contains
   * an invalid DOS 8.3 file name, the FAT volume has not been initialized,
   * a file is already open, the file already exists, the root
   * directory is full or an I/O error.
   *
   */
  bool SdBaseFile::createContiguous(SdBaseFile* dirFile,
          const char* path, uint32_t size) {
    uint32_t count;
    // don't allow zero length file
    if (size == 0) goto fail;
    if (!open(dirFile, path, O_CREAT | O_EXCL | O_RDWR)) goto fail;
  
    // calculate number of clusters needed
    count = ((size - 1) >> (vol_->clusterSizeShift_ + 9)) + 1;
  
    // allocate clusters
    if (!vol_->allocContiguous(count, &firstCluster_)) {
      remove();
      goto fail;
    }
    fileSize_ = size;
  
    // insure sync() will update dir entry
    flags_ |= F_FILE_DIR_DIRTY;
  
    return sync();
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  /** Return a file's directory entry.
   *
   * \param[out] dir Location for return of the file's directory entry.
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   */
  bool SdBaseFile::dirEntry(dir_t* dir) {
    dir_t* p;
    // make sure fields on SD are correct
    if (!sync()) goto fail;
  
    // read entry
    p = cacheDirEntry(SdVolume::CACHE_FOR_READ);
    if (!p) goto fail;
  
    // copy to caller's struct
    memcpy(dir, p, sizeof(dir_t));
    return true;
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  /** Format the name field of \a dir into the 13 byte array
   * \a name in standard 8.3 short name format.
   *
   * \param[in] dir The directory structure containing the name.
   * \param[out] name A 13 byte char array for the formatted name.
   */
  void SdBaseFile::dirName(const dir_t& dir, char* name) {
    uint8_t j = 0;
    for (uint8_t i = 0; i < 11; i++) {
      if (dir.name[i] == ' ')continue;
      if (i == 8) name[j++] = '.';
      name[j++] = dir.name[i];
    }
    name[j] = 0;
  }
  //------------------------------------------------------------------------------
  /** Test for the existence of a file in a directory
   *
   * \param[in] name Name of the file to be tested for.
   *
   * The calling instance must be an open directory file.
   *
   * dirFile.exists("TOFIND.TXT") searches for "TOFIND.TXT" in  the directory
   * dirFile.
   *
   * \return true if the file exists else false.
   */
  bool SdBaseFile::exists(const char* name) {
    SdBaseFile file;
    return file.open(this, name, O_READ);
  }
  //------------------------------------------------------------------------------
  /**
   * Get a string from a file.
   *
   * fgets() reads bytes from a file into the array pointed to by \a str, until
   * \a num - 1 bytes are read, or a delimiter is read and transferred to \a str,
   * or end-of-file is encountered. The string is then terminated
   * with a null byte.
   *
   * fgets() deletes CR, '\\r', from the string.  This insures only a '\\n'
   * terminates the string for Windows text files which use CRLF for newline.
   *
   * \param[out] str Pointer to the array where the string is stored.
   * \param[in] num Maximum number of characters to be read
   * (including the final null byte). Usually the length
   * of the array \a str is used.
   * \param[in] delim Optional set of delimiters. The default is "\n".
   *
   * \return For success fgets() returns the length of the string in \a str.
   * If no data is read, fgets() returns zero for EOF or -1 if an error occurred.
   **/
  int16_t SdBaseFile::fgets(char* str, int16_t num, char* delim) {
    char ch;
    int16_t n = 0;
    int16_t r = -1;
    while ((n + 1) < num && (r = read(&ch, 1)) == 1) {
      // delete CR
      if (ch == '\r') continue;
      str[n++] = ch;
      if (!delim) {
        if (ch == '\n') break;
      } else {
        if (strchr(delim, ch)) break;
      }
    }
    if (r < 0) {
      // read error
      return -1;
    }
    str[n] = '\0';
    return n;
  }
  //------------------------------------------------------------------------------
  /** Get a file's name
   *
   * \param[out] name An array of 13 characters for the file's name.
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   */
  bool SdBaseFile::getFilename(char* name) {
    if (!isOpen()) return false;
  
    if (isRoot()) {
      name[0] = '/';
      name[1] = '\0';
      return true;
    }
    // cache entry
    dir_t* p = cacheDirEntry(SdVolume::CACHE_FOR_READ);
    if (!p) return false;
  
    // format name
    dirName(*p, name);
    return true;
  }
  //------------------------------------------------------------------------------
  void SdBaseFile::getpos(filepos_t* pos) {
    pos->position = curPosition_;
    pos->cluster = curCluster_;
  }
  
  //------------------------------------------------------------------------------
  /** List directory contents.
   *
   * \param[in] pr Print stream for list.
   *
   * \param[in] flags The inclusive OR of
   *
   * LS_DATE - %Print file modification date
   *
   * LS_SIZE - %Print file size.
   *
   * LS_R - Recursive list of subdirectories.
   *
   * \param[in] indent Amount of space before file name. Used for recursive
   * list to indicate subdirectory level.
   */
  void SdBaseFile::ls(uint8_t flags, uint8_t indent) {
    rewind();
    int8_t status;
    while ((status = lsPrintNext( flags, indent))) {
      if (status > 1 && (flags & LS_R)) {
        uint16_t index = curPosition()/32 - 1;
        SdBaseFile s;
        if (s.open(this, index, O_READ)) s.ls( flags, indent + 2);
        seekSet(32 * (index + 1));
      }
    }
  }
  //------------------------------------------------------------------------------
  // saves 32 bytes on stack for ls recursion
  // return 0 - EOF, 1 - normal file, or 2 - directory
  int8_t SdBaseFile::lsPrintNext( uint8_t flags, uint8_t indent) {
    dir_t dir;
    uint8_t w = 0;
  
    while (1) {
      if (read(&dir, sizeof(dir)) != sizeof(dir)) return 0;
      if (dir.name[0] == DIR_NAME_FREE) return 0;
  
      // skip deleted entry and entries for . and  ..
      if (dir.name[0] != DIR_NAME_DELETED && dir.name[0] != '.'
        && DIR_IS_FILE_OR_SUBDIR(&dir)) break;
    }
    // indent for dir level
    for (uint8_t i = 0; i < indent; i++) MYSERIAL.write(' ');
  
    // print name
    for (uint8_t i = 0; i < 11; i++) {
      if (dir.name[i] == ' ')continue;
      if (i == 8) {
        MYSERIAL.write('.');
        w++;
      }
      MYSERIAL.write(dir.name[i]);
      w++;
    }
    if (DIR_IS_SUBDIR(&dir)) {
      MYSERIAL.write('/');
      w++;
    }
    if (flags & (LS_DATE | LS_SIZE)) {
      while (w++ < 14) MYSERIAL.write(' ');
    }
    // print modify date/time if requested
    if (flags & LS_DATE) {
      MYSERIAL.write(' ');
      printFatDate( dir.lastWriteDate);
      MYSERIAL.write(' ');
      printFatTime( dir.lastWriteTime);
    }
    // print size if requested
    if (!DIR_IS_SUBDIR(&dir) && (flags & LS_SIZE)) {
      MYSERIAL.write(' ');
      MYSERIAL.print(dir.fileSize);
    }
    MYSERIAL.println();
    return DIR_IS_FILE(&dir) ? 1 : 2;
  }
  //------------------------------------------------------------------------------
  // format directory name field from a 8.3 name string
  bool SdBaseFile::make83Name(const char* str, uint8_t* name, const char** ptr) {
    uint8_t c;
    uint8_t n = 7;  // max index for part before dot
    uint8_t i = 0;
    // blank fill name and extension
    while (i < 11) name[i++] = ' ';
    i = 0;
    while (*str != '\0' && *str != '/') {
      c = *str++;
      if (c == '.') {
        if (n == 10) goto fail;  // only one dot allowed
        n = 10;  // max index for full 8.3 name
        i = 8;   // place for extension
      } else {
        // illegal FAT characters
        PGM_P p = PSTR("|<>^+=?/[];,*\"\\");
        uint8_t b;
        while ((b = pgm_read_byte(p++))) if (b == c) goto fail;
        // check size and only allow ASCII printable characters
        if (i > n || c < 0X21 || c > 0X7E)goto fail;
        // only upper case allowed in 8.3 names - convert lower to upper
        name[i++] = (c < 'a' || c > 'z') ?  (c) : (c + ('A' - 'a'));
      }
    }
    *ptr = str;
    // must have a file name, extension is optional
    return name[0] != ' ';
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  /** Make a new directory.
   *
   * \param[in] parent An open SdFat instance for the directory that will contain
   * the new directory.
   *
   * \param[in] path A path with a valid 8.3 DOS name for the new directory.
   *
   * \param[in] pFlag Create missing parent directories if true.
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   * Reasons for failure include this file is already open, \a parent is not a
   * directory, \a path is invalid or already exists in \a parent.
   */
  bool SdBaseFile::mkdir(SdBaseFile* parent, const char* path, bool pFlag) {
    uint8_t dname[11];
    SdBaseFile dir1, dir2;
    SdBaseFile* sub = &dir1;
    SdBaseFile* start = parent;
  
    if (!parent || isOpen()) goto fail;
  
    if (*path == '/') {
      while (*path == '/') path++;
      if (!parent->isRoot()) {
        if (!dir2.openRoot(parent->vol_)) goto fail;
        parent = &dir2;
      }
    }
    while (1) {
      if (!make83Name(path, dname, &path)) goto fail;
      while (*path == '/') path++;
      if (!*path) break;
      if (!sub->open(parent, dname, O_READ)) {
        if (!pFlag || !sub->mkdir(parent, dname)) {
          goto fail;
        }
      }
      if (parent != start) parent->close();
      parent = sub;
      sub = parent != &dir1 ? &dir1 : &dir2;
    }
    return mkdir(parent, dname);
  
    fail:
    return false;
  }
  //------------------------------------------------------------------------------
  bool SdBaseFile::mkdir(SdBaseFile* parent, const uint8_t dname[11]) {
    uint32_t block;
    dir_t d;
    dir_t* p;
  
    if (!parent->isDir()) goto fail;
  
    // create a normal file
    if (!open(parent, dname, O_CREAT | O_EXCL | O_RDWR)) goto fail;
  
    // convert file to directory
    flags_ = O_READ;
    type_ = FAT_FILE_TYPE_SUBDIR;
  
    // allocate and zero first cluster
    if (!addDirCluster())goto fail;
  
    // force entry to SD
    if (!sync()) goto fail;
  
    // cache entry - should already be in cache due to sync() call
    p = cacheDirEntry(SdVolume::CACHE_FOR_WRITE);
    if (!p) goto fail;
  
    // change directory entry  attribute
    p->attributes = DIR_ATT_DIRECTORY;
  
    // make entry for '.'
    memcpy(&d, p, sizeof(d));
    d.name[0] = '.';
    for (uint8_t i = 1; i < 11; i++) d.name[i] = ' ';
  
    // cache block for '.'  and '..'
    block = vol_->clusterStartBlock(firstCluster_);
    if (!vol_->cacheRawBlock(block, SdVolume::CACHE_FOR_WRITE)) goto fail;
  
    // copy '.' to block
    memcpy(&vol_->cache()->dir[0], &d, sizeof(d));
  
    // make entry for '..'
    d.name[1] = '.';
    if (parent->isRoot()) {
      d.firstClusterLow = 0;
      d.firstClusterHigh = 0;
    } else {
      d.firstClusterLow = parent->firstCluster_ & 0XFFFF;
      d.firstClusterHigh = parent->firstCluster_ >> 16;
    }
    // copy '..' to block
    memcpy(&vol_->cache()->dir[1], &d, sizeof(d));
  
    // write first block
    return vol_->cacheFlush();
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
   /** Open a file in the current working directory.
    *
    * \param[in] path A path with a valid 8.3 DOS name for a file to be opened.
    *
    * \param[in] oflag Values for \a oflag are constructed by a bitwise-inclusive
    * OR of open flags. see SdBaseFile::open(SdBaseFile*, const char*, uint8_t).
    *
    * \return The value one, true, is returned for success and
    * the value zero, false, is returned for failure.
    */
    bool SdBaseFile::open(const char* path, uint8_t oflag) {
      return open(cwd_, path, oflag);
    }
  //------------------------------------------------------------------------------
  /** Open a file or directory by name.
   *
   * \param[in] dirFile An open SdFat instance for the directory containing the
   * file to be opened.
   *
   * \param[in] path A path with a valid 8.3 DOS name for a file to be opened.
   *
   * \param[in] oflag Values for \a oflag are constructed by a bitwise-inclusive
   * OR of flags from the following list
   *
   * O_READ - Open for reading.
   *
   * O_RDONLY - Same as O_READ.
   *
   * O_WRITE - Open for writing.
   *
   * O_WRONLY - Same as O_WRITE.
   *
   * O_RDWR - Open for reading and writing.
   *
   * O_APPEND - If set, the file offset shall be set to the end of the
   * file prior to each write.
   *
   * O_AT_END - Set the initial position at the end of the file.
   *
   * O_CREAT - If the file exists, this flag has no effect except as noted
   * under O_EXCL below. Otherwise, the file shall be created
   *
   * O_EXCL - If O_CREAT and O_EXCL are set, open() shall fail if the file exists.
   *
   * O_SYNC - Call sync() after each write.  This flag should not be used with
   * write(uint8_t), write_P(PGM_P), writeln_P(PGM_P), or the Arduino Print class.
   * These functions do character at a time writes so sync() will be called
   * after each byte.
   *
   * O_TRUNC - If the file exists and is a regular file, and the file is
   * successfully opened and is not read only, its length shall be truncated to 0.
   *
   * WARNING: A given file must not be opened by more than one SdBaseFile object
   * of file corruption may occur.
   *
   * \note Directory files must be opened read only.  Write and truncation is
   * not allowed for directory files.
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   * Reasons for failure include this file is already open, \a dirFile is not
   * a directory, \a path is invalid, the file does not exist
   * or can't be opened in the access mode specified by oflag.
   */
  bool SdBaseFile::open(SdBaseFile* dirFile, const char* path, uint8_t oflag) {
    uint8_t dname[11];
    SdBaseFile dir1, dir2;
    SdBaseFile *parent = dirFile;
    SdBaseFile *sub = &dir1;
  
    if (!dirFile) goto fail;
  
    // error if already open
    if (isOpen()) goto fail;
  
    if (*path == '/') {
      while (*path == '/') path++;
      if (!dirFile->isRoot()) {
        if (!dir2.openRoot(dirFile->vol_)) goto fail;
        parent = &dir2;
      }
    }
    while (1) {
      if (!make83Name(path, dname, &path)) goto fail;
      while (*path == '/') path++;
      if (!*path) break;
      if (!sub->open(parent, dname, O_READ)) goto fail;
      if (parent != dirFile) parent->close();
      parent = sub;
      sub = parent != &dir1 ? &dir1 : &dir2;
    }
    return open(parent, dname, oflag);
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  // open with filename in dname
  bool SdBaseFile::open(SdBaseFile* dirFile,
    const uint8_t dname[11], uint8_t oflag) {
    bool emptyFound = false;
    bool fileFound = false;
    uint8_t index;
    dir_t* p;
  
    vol_ = dirFile->vol_;
  
    dirFile->rewind();
    // search for file
  
    while (dirFile->curPosition_ < dirFile->fileSize_) {
      index = 0XF & (dirFile->curPosition_ >> 5);
      p = dirFile->readDirCache();
      if (!p) goto fail;
  
      if (p->name[0] == DIR_NAME_FREE || p->name[0] == DIR_NAME_DELETED) {
        // remember first empty slot
        if (!emptyFound) {
          dirBlock_ = dirFile->vol_->cacheBlockNumber();
          dirIndex_ = index;
          emptyFound = true;
        }
        // done if no entries follow
        if (p->name[0] == DIR_NAME_FREE) break;
      } else if (!memcmp(dname, p->name, 11)) {
        fileFound = true;
        break;
      }
    }
    if (fileFound) {
      // don't open existing file if O_EXCL
      if (oflag & O_EXCL) goto fail;
    } else {
      // don't create unless O_CREAT and O_WRITE
      if (!(oflag & O_CREAT) || !(oflag & O_WRITE)) goto fail;
      if (emptyFound) {
        index = dirIndex_;
        p = cacheDirEntry(SdVolume::CACHE_FOR_WRITE);
        if (!p) goto fail;
      } else {
        if (dirFile->type_ == FAT_FILE_TYPE_ROOT_FIXED) goto fail;
  
        // add and zero cluster for dirFile - first cluster is in cache for write
        if (!dirFile->addDirCluster()) goto fail;
  
        // use first entry in cluster
        p = dirFile->vol_->cache()->dir;
        index = 0;
      }
      // initialize as empty file
      memset(p, 0, sizeof(dir_t));
      memcpy(p->name, dname, 11);
  
      // set timestamps
      if (dateTime_) {
        // call user date/time function
        dateTime_(&p->creationDate, &p->creationTime);
      } else {
        // use default date/time
        p->creationDate = FAT_DEFAULT_DATE;
        p->creationTime = FAT_DEFAULT_TIME;
      }
      p->lastAccessDate = p->creationDate;
      p->lastWriteDate = p->creationDate;
      p->lastWriteTime = p->creationTime;
  
      // write entry to SD
      if (!dirFile->vol_->cacheFlush()) goto fail;
    }
    // open entry in cache
    return openCachedEntry(index, oflag);
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  /** Open a file by index.
   *
   * \param[in] dirFile An open SdFat instance for the directory.
   *
   * \param[in] index The \a index of the directory entry for the file to be
   * opened.  The value for \a index is (directory file position)/32.
   *
   * \param[in] oflag Values for \a oflag are constructed by a bitwise-inclusive
   * OR of flags O_READ, O_WRITE, O_TRUNC, and O_SYNC.
   *
   * See open() by path for definition of flags.
   * \return true for success or false for failure.
   */
  bool SdBaseFile::open(SdBaseFile* dirFile, uint16_t index, uint8_t oflag) {
    dir_t* p;
  
    vol_ = dirFile->vol_;
  
    // error if already open
    if (isOpen() || !dirFile) goto fail;
  
    // don't open existing file if O_EXCL - user call error
    if (oflag & O_EXCL) goto fail;
  
    // seek to location of entry
    if (!dirFile->seekSet(32 * index)) goto fail;
  
    // read entry into cache
    p = dirFile->readDirCache();
    if (!p) goto fail;
  
    // error if empty slot or '.' or '..'
    if (p->name[0] == DIR_NAME_FREE ||
        p->name[0] == DIR_NAME_DELETED || p->name[0] == '.') {
      goto fail;
    }
    // open cached entry
    return openCachedEntry(index & 0XF, oflag);
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  // open a cached directory entry. Assumes vol_ is initialized
  bool SdBaseFile::openCachedEntry(uint8_t dirIndex, uint8_t oflag) {
    // location of entry in cache
    dir_t* p = &vol_->cache()->dir[dirIndex];
  
    // write or truncate is an error for a directory or read-only file
    if (p->attributes & (DIR_ATT_READ_ONLY | DIR_ATT_DIRECTORY)) {
      if (oflag & (O_WRITE | O_TRUNC)) goto fail;
    }
    // remember location of directory entry on SD
    dirBlock_ = vol_->cacheBlockNumber();
    dirIndex_ = dirIndex;
  
    // copy first cluster number for directory fields
    firstCluster_ = (uint32_t)p->firstClusterHigh << 16;
    firstCluster_ |= p->firstClusterLow;
  
    // make sure it is a normal file or subdirectory
    if (DIR_IS_FILE(p)) {
      fileSize_ = p->fileSize;
      type_ = FAT_FILE_TYPE_NORMAL;
    } else if (DIR_IS_SUBDIR(p)) {
      if (!vol_->chainSize(firstCluster_, &fileSize_)) goto fail;
      type_ = FAT_FILE_TYPE_SUBDIR;
    } else {
      goto fail;
    }
    // save open flags for read/write
    flags_ = oflag & F_OFLAG;
  
    // set to start of file
    curCluster_ = 0;
    curPosition_ = 0;
    if ((oflag & O_TRUNC) && !truncate(0)) return false;
    return oflag & O_AT_END ? seekEnd(0) : true;
  
   fail:
    type_ = FAT_FILE_TYPE_CLOSED;
    return false;
  }
  //------------------------------------------------------------------------------
  /** Open the next file or subdirectory in a directory.
   *
   * \param[in] dirFile An open SdFat instance for the directory containing the
   * file to be opened.
   *
   * \param[in] oflag Values for \a oflag are constructed by a bitwise-inclusive
   * OR of flags O_READ, O_WRITE, O_TRUNC, and O_SYNC.
   *
   * See open() by path for definition of flags.
   * \return true for success or false for failure.
   */
  bool SdBaseFile::openNext(SdBaseFile* dirFile, uint8_t oflag) {
    dir_t* p;
    uint8_t index;
  
    if (!dirFile) goto fail;
  
    // error if already open
    if (isOpen()) goto fail;
  
    vol_ = dirFile->vol_;
  
    while (1) {
      index = 0XF & (dirFile->curPosition_ >> 5);
  
      // read entry into cache
      p = dirFile->readDirCache();
      if (!p) goto fail;
  
      // done if last entry
      if (p->name[0] == DIR_NAME_FREE) goto fail;
  
      // skip empty slot or '.' or '..'
      if (p->name[0] == DIR_NAME_DELETED || p->name[0] == '.') {
        continue;
      }
      // must be file or dir
      if (DIR_IS_FILE_OR_SUBDIR(p)) {
        return openCachedEntry(index, oflag);
      }
    }
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  /** Open a directory's parent directory.
   *
   * \param[in] dir Parent of this directory will be opened.  Must not be root.
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   */
  bool SdBaseFile::openParent(SdBaseFile* dir) {
    dir_t entry;
    dir_t* p;
    SdBaseFile file;
    uint32_t c;
    uint32_t cluster;
    uint32_t lbn;
    // error if already open or dir is root or dir is not a directory
    if (isOpen() || !dir || dir->isRoot() || !dir->isDir()) goto fail;
    vol_ = dir->vol_;
    // position to '..'
    if (!dir->seekSet(32)) goto fail;
    // read '..' entry
    if (dir->read(&entry, sizeof(entry)) != 32) goto fail;
    // verify it is '..'
    if (entry.name[0] != '.' || entry.name[1] != '.') goto fail;
    // start cluster for '..'
    cluster = entry.firstClusterLow;
    cluster |= (uint32_t)entry.firstClusterHigh << 16;
    if (cluster == 0) return openRoot(vol_);
    // start block for '..'
    lbn = vol_->clusterStartBlock(cluster);
    // first block of parent dir
    if (!vol_->cacheRawBlock(lbn, SdVolume::CACHE_FOR_READ)) {
      goto fail;
    }
    p = &vol_->cacheBuffer_.dir[1];
    // verify name for '../..'
    if (p->name[0] != '.' || p->name[1] != '.') goto fail;
    // '..' is pointer to first cluster of parent. open '../..' to find parent
    if (p->firstClusterHigh == 0 && p->firstClusterLow == 0) {
      if (!file.openRoot(dir->volume())) goto fail;
    } else {
      if (!file.openCachedEntry(1, O_READ)) goto fail;
    }
    // search for parent in '../..'
    do {
      if (file.readDir(&entry, NULL) != 32) goto fail;
      c = entry.firstClusterLow;
      c |= (uint32_t)entry.firstClusterHigh << 16;
    } while (c != cluster);
    // open parent
    return open(&file, file.curPosition()/32 - 1, O_READ);
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  /** Open a volume's root directory.
   *
   * \param[in] vol The FAT volume containing the root directory to be opened.
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   * Reasons for failure include the file is already open, the FAT volume has
   * not been initialized or it a FAT12 volume.
   */
  bool SdBaseFile::openRoot(SdVolume* vol) {
    // error if file is already open
    if (isOpen()) goto fail;
  
    if (vol->fatType() == 16 || (FAT12_SUPPORT && vol->fatType() == 12)) {
      type_ = FAT_FILE_TYPE_ROOT_FIXED;
      firstCluster_ = 0;
      fileSize_ = 32 * vol->rootDirEntryCount();
    } else if (vol->fatType() == 32) {
      type_ = FAT_FILE_TYPE_ROOT32;
      firstCluster_ = vol->rootDirStart();
      if (!vol->chainSize(firstCluster_, &fileSize_)) goto fail;
    } else {
      // volume is not initialized, invalid, or FAT12 without support
      return false;
    }
    vol_ = vol;
    // read only
    flags_ = O_READ;
  
    // set to start of file
    curCluster_ = 0;
    curPosition_ = 0;
  
    // root has no directory entry
    dirBlock_ = 0;
    dirIndex_ = 0;
    return true;
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  /** Return the next available byte without consuming it.
   *
   * \return The byte if no error and not at eof else -1;
   */
  int SdBaseFile::peek() {
    filepos_t pos;
    getpos(&pos);
    int c = read();
    if (c >= 0) setpos(&pos);
    return c;
  }
  
  //------------------------------------------------------------------------------
  /** %Print the name field of a directory entry in 8.3 format.
   * \param[in] pr Print stream for output.
   * \param[in] dir The directory structure containing the name.
   * \param[in] width Blank fill name if length is less than \a width.
   * \param[in] printSlash Print '/' after directory names if true.
   */
  void SdBaseFile::printDirName(const dir_t& dir,
    uint8_t width, bool printSlash) {
    uint8_t w = 0;
    for (uint8_t i = 0; i < 11; i++) {
      if (dir.name[i] == ' ')continue;
      if (i == 8) {
        MYSERIAL.write('.');
        w++;
      }
      MYSERIAL.write(dir.name[i]);
      w++;
    }
    if (DIR_IS_SUBDIR(&dir) && printSlash) {
      MYSERIAL.write('/');
      w++;
    }
    while (w < width) {
      MYSERIAL.write(' ');
      w++;
    }
  }
  //------------------------------------------------------------------------------
  // print uint8_t with width 2
  static void print2u( uint8_t v) {
    if (v < 10) MYSERIAL.write('0');
    MYSERIAL.print(v, DEC);
  }
  //------------------------------------------------------------------------------
  /** %Print a directory date field to Serial.
   *
   *  Format is yyyy-mm-dd.
   *
   * \param[in] fatDate The date field from a directory entry.
   */
  
  //------------------------------------------------------------------------------
  /** %Print a directory date field.
   *
   *  Format is yyyy-mm-dd.
   *
   * \param[in] pr Print stream for output.
   * \param[in] fatDate The date field from a directory entry.
   */
  void SdBaseFile::printFatDate(uint16_t fatDate) {
    MYSERIAL.print(FAT_YEAR(fatDate));
    MYSERIAL.write('-');
    print2u( FAT_MONTH(fatDate));
    MYSERIAL.write('-');
    print2u( FAT_DAY(fatDate));
  }
  
  //------------------------------------------------------------------------------
  /** %Print a directory time field.
   *
   * Format is hh:mm:ss.
   *
   * \param[in] pr Print stream for output.
   * \param[in] fatTime The time field from a directory entry.
   */
  void SdBaseFile::printFatTime( uint16_t fatTime) {
    print2u( FAT_HOUR(fatTime));
    MYSERIAL.write(':');
    print2u( FAT_MINUTE(fatTime));
    MYSERIAL.write(':');
    print2u( FAT_SECOND(fatTime));
  }
  //------------------------------------------------------------------------------
  /** Print a file's name to Serial
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   */
  bool SdBaseFile::printName() {
    char name[13];
    if (!getFilename(name)) return false;
    MYSERIAL.print(name);
    return true;
  }
  //------------------------------------------------------------------------------
  /** Read the next byte from a file.
   *
   * \return For success read returns the next byte in the file as an int.
   * If an error occurs or end of file is reached -1 is returned.
   */
  int16_t SdBaseFile::read() {
    uint8_t b;
    return read(&b, 1) == 1 ? b : -1;
  }
  //------------------------------------------------------------------------------
  /** Read data from a file starting at the current position.
   *
   * \param[out] buf Pointer to the location that will receive the data.
   *
   * \param[in] nbyte Maximum number of bytes to read.
   *
   * \return For success read() returns the number of bytes read.
   * A value less than \a nbyte, including zero, will be returned
   * if end of file is reached.
   * If an error occurs, read() returns -1.  Possible errors include
   * read() called before a file has been opened, corrupt file system
   * or an I/O error occurred.
   */
  int16_t SdBaseFile::read(void* buf, uint16_t nbyte) {
    uint8_t* dst = reinterpret_cast<uint8_t*>(buf);
    uint16_t offset;
    uint16_t toRead;
    uint32_t block;  // raw device block number
  
    // error if not open or write only
    if (!isOpen() || !(flags_ & O_READ)) goto fail;
  
    // max bytes left in file
    if (nbyte >= (fileSize_ - curPosition_)) {
      nbyte = fileSize_ - curPosition_;
    }
    // amount left to read
    toRead = nbyte;
    while (toRead > 0) {
      offset = curPosition_ & 0X1FF;  // offset in block
      if (type_ == FAT_FILE_TYPE_ROOT_FIXED) {
        block = vol_->rootDirStart() + (curPosition_ >> 9);
      } else {
        uint8_t blockOfCluster = vol_->blockOfCluster(curPosition_);
        if (offset == 0 && blockOfCluster == 0) {
          // start of new cluster
          if (curPosition_ == 0) {
            // use first cluster in file
            curCluster_ = firstCluster_;
          } else {
            // get next cluster from FAT
            if (!vol_->fatGet(curCluster_, &curCluster_)) goto fail;
          }
        }
        block = vol_->clusterStartBlock(curCluster_) + blockOfCluster;
      }
      uint16_t n = toRead;
  
      // amount to be read from current block
      if (n > (512 - offset)) n = 512 - offset;
  
      // no buffering needed if n == 512
      if (n == 512 && block != vol_->cacheBlockNumber()) {
        if (!vol_->readBlock(block, dst)) goto fail;
      } else {
        // read block to cache and copy data to caller
        if (!vol_->cacheRawBlock(block, SdVolume::CACHE_FOR_READ)) goto fail;
        uint8_t* src = vol_->cache()->data + offset;
        memcpy(dst, src, n);
      }
      dst += n;
      curPosition_ += n;
      toRead -= n;
    }
    return nbyte;
  
   fail:
    return -1;
  }
  //------------------------------------------------------------------------------
  /** Read the next directory entry from a directory file.
   *
   * \param[out] dir The dir_t struct that will receive the data.
   *
   * \return For success readDir() returns the number of bytes read.
   * A value of zero will be returned if end of file is reached.
   * If an error occurs, readDir() returns -1.  Possible errors include
   * readDir() called before a directory has been opened, this is not
   * a directory file or an I/O error occurred.
   */
  int8_t SdBaseFile::readDir(dir_t* dir, char* longFilename) {
    int16_t n;
    // if not a directory file or miss-positioned return an error
    if (!isDir() || (0X1F & curPosition_)) return -1;
    
    //If we have a longFilename buffer, mark it as invalid. If we find a long filename it will be filled automaticly.
    if (longFilename != NULL)
    {
    	longFilename[0] = '\0';
    }
  
    while (1) {
      n = read(dir, sizeof(dir_t));
      if (n != sizeof(dir_t)) return n == 0 ? 0 : -1;
      // last entry if DIR_NAME_FREE
      if (dir->name[0] == DIR_NAME_FREE) return 0;
      // skip empty entries and entry for .  and ..
      if (dir->name[0] == DIR_NAME_DELETED || dir->name[0] == '.') continue;
      //Fill the long filename if we have a long filename entry,
  	// long filename entries are stored before the actual filename.
  	if (DIR_IS_LONG_NAME(dir) && longFilename != NULL)
      {
      	vfat_t *VFAT = (vfat_t*)dir;
  		//Sanity check the VFAT entry. The first cluster is always set to zero. And th esequence number should be higher then 0
      	if (VFAT->firstClusterLow == 0 && (VFAT->sequenceNumber & 0x1F) > 0 && (VFAT->sequenceNumber & 0x1F) <= MAX_VFAT_ENTRIES)
      	{
  			//TODO: Store the filename checksum to verify if a none-long filename aware system modified the file table.
      		n = ((VFAT->sequenceNumber & 0x1F) - 1) * 13;
  			longFilename[n+0] = VFAT->name1[0];
  			longFilename[n+1] = VFAT->name1[1];
  			longFilename[n+2] = VFAT->name1[2];
  			longFilename[n+3] = VFAT->name1[3];
  			longFilename[n+4] = VFAT->name1[4];
  			longFilename[n+5] = VFAT->name2[0];
  			longFilename[n+6] = VFAT->name2[1];
  			longFilename[n+7] = VFAT->name2[2];
  			longFilename[n+8] = VFAT->name2[3];
  			longFilename[n+9] = VFAT->name2[4];
  			longFilename[n+10] = VFAT->name2[5];
  			longFilename[n+11] = VFAT->name3[0];
  			longFilename[n+12] = VFAT->name3[1];
  			//If this VFAT entry is the last one, add a NUL terminator at the end of the string
  			if (VFAT->sequenceNumber & 0x40)
  				longFilename[n+13] = '\0';
  		}
      }
      // return if normal file or subdirectory
      if (DIR_IS_FILE_OR_SUBDIR(dir)) return n;
    }
  }
  //------------------------------------------------------------------------------
  // Read next directory entry into the cache
  // Assumes file is correctly positioned
  dir_t* SdBaseFile::readDirCache() {
    uint8_t i;
    // error if not directory
    if (!isDir()) goto fail;
  
    // index of entry in cache
    i = (curPosition_ >> 5) & 0XF;
  
    // use read to locate and cache block
    if (read() < 0) goto fail;
  
    // advance to next entry
    curPosition_ += 31;
  
    // return pointer to entry
    return vol_->cache()->dir + i;
  
   fail:
    return 0;
  }
  //------------------------------------------------------------------------------
  /** Remove a file.
   *
   * The directory entry and all data for the file are deleted.
   *
   * \note This function should not be used to delete the 8.3 version of a
   * file that has a long name. For example if a file has the long name
   * "New Text Document.txt" you should not delete the 8.3 name "NEWTEX~1.TXT".
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   * Reasons for failure include the file read-only, is a directory,
   * or an I/O error occurred.
   */
  bool SdBaseFile::remove() {
    dir_t* d;
    // free any clusters - will fail if read-only or directory
    if (!truncate(0)) goto fail;
  
    // cache directory entry
    d = cacheDirEntry(SdVolume::CACHE_FOR_WRITE);
    if (!d) goto fail;
  
    // mark entry deleted
    d->name[0] = DIR_NAME_DELETED;
  
    // set this file closed
    type_ = FAT_FILE_TYPE_CLOSED;
  
    // write entry to SD
    return vol_->cacheFlush();
    return true;
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  /** Remove a file.
   *
   * The directory entry and all data for the file are deleted.
   *
   * \param[in] dirFile The directory that contains the file.
   * \param[in] path Path for the file to be removed.
   *
   * \note This function should not be used to delete the 8.3 version of a
   * file that has a long name. For example if a file has the long name
   * "New Text Document.txt" you should not delete the 8.3 name "NEWTEX~1.TXT".
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   * Reasons for failure include the file is a directory, is read only,
   * \a dirFile is not a directory, \a path is not found
   * or an I/O error occurred.
   */
  bool SdBaseFile::remove(SdBaseFile* dirFile, const char* path) {
    SdBaseFile file;
    if (!file.open(dirFile, path, O_WRITE)) goto fail;
    return file.remove();
  
   fail:
    // can't set iostate - static function
    return false;
  }
  //------------------------------------------------------------------------------
  /** Rename a file or subdirectory.
   *
   * \param[in] dirFile Directory for the new path.
   * \param[in] newPath New path name for the file/directory.
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   * Reasons for failure include \a dirFile is not open or is not a directory
   * file, newPath is invalid or already exists, or an I/O error occurs.
   */
  bool SdBaseFile::rename(SdBaseFile* dirFile, const char* newPath) {
    dir_t entry;
    uint32_t dirCluster = 0;
    SdBaseFile file;
    dir_t* d;
  
    // must be an open file or subdirectory
    if (!(isFile() || isSubDir())) goto fail;
  
    // can't move file
    if (vol_ != dirFile->vol_) goto fail;
  
    // sync() and cache directory entry
    sync();
    d = cacheDirEntry(SdVolume::CACHE_FOR_WRITE);
    if (!d) goto fail;
  
    // save directory entry
    memcpy(&entry, d, sizeof(entry));
  
    // mark entry deleted
    d->name[0] = DIR_NAME_DELETED;
  
    // make directory entry for new path
    if (isFile()) {
      if (!file.open(dirFile, newPath, O_CREAT | O_EXCL | O_WRITE)) {
        goto restore;
      }
    } else {
      // don't create missing path prefix components
      if (!file.mkdir(dirFile, newPath, false)) {
        goto restore;
      }
      // save cluster containing new dot dot
      dirCluster = file.firstCluster_;
    }
    // change to new directory entry
    dirBlock_ = file.dirBlock_;
    dirIndex_ = file.dirIndex_;
  
    // mark closed to avoid possible destructor close call
    file.type_ = FAT_FILE_TYPE_CLOSED;
  
    // cache new directory entry
    d = cacheDirEntry(SdVolume::CACHE_FOR_WRITE);
    if (!d) goto fail;
  
    // copy all but name field to new directory entry
    memcpy(&d->attributes, &entry.attributes, sizeof(entry) - sizeof(d->name));
  
    // update dot dot if directory
    if (dirCluster) {
      // get new dot dot
      uint32_t block = vol_->clusterStartBlock(dirCluster);
      if (!vol_->cacheRawBlock(block, SdVolume::CACHE_FOR_READ)) goto fail;
      memcpy(&entry, &vol_->cache()->dir[1], sizeof(entry));
  
      // free unused cluster
      if (!vol_->freeChain(dirCluster)) goto fail;
  
      // store new dot dot
      block = vol_->clusterStartBlock(firstCluster_);
      if (!vol_->cacheRawBlock(block, SdVolume::CACHE_FOR_WRITE)) goto fail;
      memcpy(&vol_->cache()->dir[1], &entry, sizeof(entry));
    }
    return vol_->cacheFlush();
  
   restore:
    d = cacheDirEntry(SdVolume::CACHE_FOR_WRITE);
    if (!d) goto fail;
    // restore entry
    d->name[0] = entry.name[0];
    vol_->cacheFlush();
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  /** Remove a directory file.
   *
   * The directory file will be removed only if it is empty and is not the
   * root directory.  rmdir() follows DOS and Windows and ignores the
   * read-only attribute for the directory.
   *
   * \note This function should not be used to delete the 8.3 version of a
   * directory that has a long name. For example if a directory has the
   * long name "New folder" you should not delete the 8.3 name "NEWFOL~1".
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   * Reasons for failure include the file is not a directory, is the root
   * directory, is not empty, or an I/O error occurred.
   */
  bool SdBaseFile::rmdir() {
    // must be open subdirectory
    if (!isSubDir()) goto fail;
  
    rewind();
  
    // make sure directory is empty
    while (curPosition_ < fileSize_) {
      dir_t* p = readDirCache();
      if (!p) goto fail;
      // done if past last used entry
      if (p->name[0] == DIR_NAME_FREE) break;
      // skip empty slot, '.' or '..'
      if (p->name[0] == DIR_NAME_DELETED || p->name[0] == '.') continue;
      // error not empty
      if (DIR_IS_FILE_OR_SUBDIR(p)) goto fail;
    }
    // convert empty directory to normal file for remove
    type_ = FAT_FILE_TYPE_NORMAL;
    flags_ |= O_WRITE;
    return remove();
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  /** Recursively delete a directory and all contained files.
   *
   * This is like the Unix/Linux 'rm -rf *' if called with the root directory
   * hence the name.
   *
   * Warning - This will remove all contents of the directory including
   * subdirectories.  The directory will then be removed if it is not root.
   * The read-only attribute for files will be ignored.
   *
   * \note This function should not be used to delete the 8.3 version of
   * a directory that has a long name.  See remove() and rmdir().
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   */
  bool SdBaseFile::rmRfStar() {
    uint16_t index;
    SdBaseFile f;
    rewind();
    while (curPosition_ < fileSize_) {
      // remember position
      index = curPosition_/32;
  
      dir_t* p = readDirCache();
      if (!p) goto fail;
  
      // done if past last entry
      if (p->name[0] == DIR_NAME_FREE) break;
  
      // skip empty slot or '.' or '..'
      if (p->name[0] == DIR_NAME_DELETED || p->name[0] == '.') continue;
  
      // skip if part of long file name or volume label in root
      if (!DIR_IS_FILE_OR_SUBDIR(p)) continue;
  
      if (!f.open(this, index, O_READ)) goto fail;
      if (f.isSubDir()) {
        // recursively delete
        if (!f.rmRfStar()) goto fail;
      } else {
        // ignore read-only
        f.flags_ |= O_WRITE;
        if (!f.remove()) goto fail;
      }
      // position to next entry if required
      if (curPosition_ != (32*(index + 1))) {
        if (!seekSet(32*(index + 1))) goto fail;
      }
    }
    // don't try to delete root
    if (!isRoot()) {
      if (!rmdir()) goto fail;
    }
    return true;
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  /**  Create a file object and open it in the current working directory.
   *
   * \param[in] path A path with a valid 8.3 DOS name for a file to be opened.
   *
   * \param[in] oflag Values for \a oflag are constructed by a bitwise-inclusive
   * OR of open flags. see SdBaseFile::open(SdBaseFile*, const char*, uint8_t).
   */
  SdBaseFile::SdBaseFile(const char* path, uint8_t oflag) {
    type_ = FAT_FILE_TYPE_CLOSED;
    writeError = false;
    open(path, oflag);
  }
  //------------------------------------------------------------------------------
  /** Sets a file's position.
   *
   * \param[in] pos The new position in bytes from the beginning of the file.
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   */
  bool SdBaseFile::seekSet(uint32_t pos) {
    uint32_t nCur;
    uint32_t nNew;
    // error if file not open or seek past end of file
    if (!isOpen() || pos > fileSize_) goto fail;
  
    if (type_ == FAT_FILE_TYPE_ROOT_FIXED) {
      curPosition_ = pos;
      goto done;
    }
    if (pos == 0) {
      // set position to start of file
      curCluster_ = 0;
      curPosition_ = 0;
      goto done;
    }
    // calculate cluster index for cur and new position
    nCur = (curPosition_ - 1) >> (vol_->clusterSizeShift_ + 9);
    nNew = (pos - 1) >> (vol_->clusterSizeShift_ + 9);
  
    if (nNew < nCur || curPosition_ == 0) {
      // must follow chain from first cluster
      curCluster_ = firstCluster_;
    } else {
      // advance from curPosition
      nNew -= nCur;
    }
    while (nNew--) {
      if (!vol_->fatGet(curCluster_, &curCluster_)) goto fail;
    }
    curPosition_ = pos;
  
   done:
    return true;
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  void SdBaseFile::setpos(filepos_t* pos) {
    curPosition_ = pos->position;
    curCluster_ = pos->cluster;
  }
  //------------------------------------------------------------------------------
  /** The sync() call causes all modified data and directory fields
   * to be written to the storage device.
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   * Reasons for failure include a call to sync() before a file has been
   * opened or an I/O error.
   */
  bool SdBaseFile::sync() {
    // only allow open files and directories
    if (!isOpen()) goto fail;
  
    if (flags_ & F_FILE_DIR_DIRTY) {
      dir_t* d = cacheDirEntry(SdVolume::CACHE_FOR_WRITE);
      // check for deleted by another open file object
      if (!d || d->name[0] == DIR_NAME_DELETED) goto fail;
  
      // do not set filesize for dir files
      if (!isDir()) d->fileSize = fileSize_;
  
      // update first cluster fields
      d->firstClusterLow = firstCluster_ & 0XFFFF;
      d->firstClusterHigh = firstCluster_ >> 16;
  
      // set modify time if user supplied a callback date/time function
      if (dateTime_) {
        dateTime_(&d->lastWriteDate, &d->lastWriteTime);
        d->lastAccessDate = d->lastWriteDate;
      }
      // clear directory dirty
      flags_ &= ~F_FILE_DIR_DIRTY;
    }
    return vol_->cacheFlush();
  
   fail:
    writeError = true;
    return false;
  }
  //------------------------------------------------------------------------------
  /** Copy a file's timestamps
   *
   * \param[in] file File to copy timestamps from.
   *
   * \note
   * Modify and access timestamps may be overwritten if a date time callback
   * function has been set by dateTimeCallback().
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   */
  bool SdBaseFile::timestamp(SdBaseFile* file) {
    dir_t* d;
    dir_t dir;
  
    // get timestamps
    if (!file->dirEntry(&dir)) goto fail;
  
    // update directory fields
    if (!sync()) goto fail;
  
    d = cacheDirEntry(SdVolume::CACHE_FOR_WRITE);
    if (!d) goto fail;
  
    // copy timestamps
    d->lastAccessDate = dir.lastAccessDate;
    d->creationDate = dir.creationDate;
    d->creationTime = dir.creationTime;
    d->creationTimeTenths = dir.creationTimeTenths;
    d->lastWriteDate = dir.lastWriteDate;
    d->lastWriteTime = dir.lastWriteTime;
  
    // write back entry
    return vol_->cacheFlush();
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  /** Set a file's timestamps in its directory entry.
   *
   * \param[in] flags Values for \a flags are constructed by a bitwise-inclusive
   * OR of flags from the following list
   *
   * T_ACCESS - Set the file's last access date.
   *
   * T_CREATE - Set the file's creation date and time.
   *
   * T_WRITE - Set the file's last write/modification date and time.
   *
   * \param[in] year Valid range 1980 - 2107 inclusive.
   *
   * \param[in] month Valid range 1 - 12 inclusive.
   *
   * \param[in] day Valid range 1 - 31 inclusive.
   *
   * \param[in] hour Valid range 0 - 23 inclusive.
   *
   * \param[in] minute Valid range 0 - 59 inclusive.
   *
   * \param[in] second Valid range 0 - 59 inclusive
   *
   * \note It is possible to set an invalid date since there is no check for
   * the number of days in a month.
   *
   * \note
   * Modify and access timestamps may be overwritten if a date time callback
   * function has been set by dateTimeCallback().
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   */
  bool SdBaseFile::timestamp(uint8_t flags, uint16_t year, uint8_t month,
           uint8_t day, uint8_t hour, uint8_t minute, uint8_t second) {
    uint16_t dirDate;
    uint16_t dirTime;
    dir_t* d;
  
    if (!isOpen()
      || year < 1980
      || year > 2107
      || month < 1
      || month > 12
      || day < 1
      || day > 31
      || hour > 23
      || minute > 59
      || second > 59) {
        goto fail;
    }
    // update directory entry
    if (!sync()) goto fail;
  
    d = cacheDirEntry(SdVolume::CACHE_FOR_WRITE);
    if (!d) goto fail;
  
    dirDate = FAT_DATE(year, month, day);
    dirTime = FAT_TIME(hour, minute, second);
    if (flags & T_ACCESS) {
      d->lastAccessDate = dirDate;
    }
    if (flags & T_CREATE) {
      d->creationDate = dirDate;
      d->creationTime = dirTime;
      // seems to be units of 1/100 second not 1/10 as Microsoft states
      d->creationTimeTenths = second & 1 ? 100 : 0;
    }
    if (flags & T_WRITE) {
      d->lastWriteDate = dirDate;
      d->lastWriteTime = dirTime;
    }
    return vol_->cacheFlush();
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  /** Truncate a file to a specified length.  The current file position
   * will be maintained if it is less than or equal to \a length otherwise
   * it will be set to end of file.
   *
   * \param[in] length The desired length for the file.
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.
   * Reasons for failure include file is read only, file is a directory,
   * \a length is greater than the current file size or an I/O error occurs.
   */
  bool SdBaseFile::truncate(uint32_t length) {
    uint32_t newPos;
    // error if not a normal file or read-only
    if (!isFile() || !(flags_ & O_WRITE)) goto fail;
  
    // error if length is greater than current size
    if (length > fileSize_) goto fail;
  
    // fileSize and length are zero - nothing to do
    if (fileSize_ == 0) return true;
  
    // remember position for seek after truncation
    newPos = curPosition_ > length ? length : curPosition_;
  
    // position to last cluster in truncated file
    if (!seekSet(length)) goto fail;
  
    if (length == 0) {
      // free all clusters
      if (!vol_->freeChain(firstCluster_)) goto fail;
      firstCluster_ = 0;
    } else {
      uint32_t toFree;
      if (!vol_->fatGet(curCluster_, &toFree)) goto fail;
  
      if (!vol_->isEOC(toFree)) {
        // free extra clusters
        if (!vol_->freeChain(toFree)) goto fail;
  
        // current cluster is end of chain
        if (!vol_->fatPutEOC(curCluster_)) goto fail;
      }
    }
    fileSize_ = length;
  
    // need to update directory entry
    flags_ |= F_FILE_DIR_DIRTY;
  
    if (!sync()) goto fail;
  
    // set file to correct position
    return seekSet(newPos);
  
   fail:
    return false;
  }
  //------------------------------------------------------------------------------
  /** Write data to an open file.
   *
   * \note Data is moved to the cache but may not be written to the
   * storage device until sync() is called.
   *
   * \param[in] buf Pointer to the location of the data to be written.
   *
   * \param[in] nbyte Number of bytes to write.
   *
   * \return For success write() returns the number of bytes written, always
   * \a nbyte.  If an error occurs, write() returns -1.  Possible errors
   * include write() is called before a file has been opened, write is called
   * for a read-only file, device is full, a corrupt file system or an I/O error.
   *
   */
  int16_t SdBaseFile::write(const void* buf, uint16_t nbyte) {
    // convert void* to uint8_t*  -  must be before goto statements
    const uint8_t* src = reinterpret_cast<const uint8_t*>(buf);
  
    // number of bytes left to write  -  must be before goto statements
    uint16_t nToWrite = nbyte;
  
    // error if not a normal file or is read-only
    if (!isFile() || !(flags_ & O_WRITE)) goto fail;
  
    // seek to end of file if append flag
    if ((flags_ & O_APPEND) && curPosition_ != fileSize_) {
      if (!seekEnd()) goto fail;
    }
  
    while (nToWrite > 0) {
      uint8_t blockOfCluster = vol_->blockOfCluster(curPosition_);
      uint16_t blockOffset = curPosition_ & 0X1FF;
      if (blockOfCluster == 0 && blockOffset == 0) {
        // start of new cluster
        if (curCluster_ == 0) {
          if (firstCluster_ == 0) {
            // allocate first cluster of file
            if (!addCluster()) goto fail;
          } else {
            curCluster_ = firstCluster_;
          }
        } else {
          uint32_t next;
          if (!vol_->fatGet(curCluster_, &next)) goto fail;
          if (vol_->isEOC(next)) {
            // add cluster if at end of chain
            if (!addCluster()) goto fail;
          } else {
            curCluster_ = next;
          }
        }
      }
      // max space in block
      uint16_t n = 512 - blockOffset;
  
      // lesser of space and amount to write
      if (n > nToWrite) n = nToWrite;
  
      // block for data write
      uint32_t block = vol_->clusterStartBlock(curCluster_) + blockOfCluster;
      if (n == 512) {
        // full block - don't need to use cache
        if (vol_->cacheBlockNumber() == block) {
          // invalidate cache if block is in cache
          vol_->cacheSetBlockNumber(0XFFFFFFFF, false);
        }
        if (!vol_->writeBlock(block, src)) goto fail;
      } else {
        if (blockOffset == 0 && curPosition_ >= fileSize_) {
          // start of new block don't need to read into cache
          if (!vol_->cacheFlush()) goto fail;
          // set cache dirty and SD address of block
          vol_->cacheSetBlockNumber(block, true);
        } else {
          // rewrite part of block
          if (!vol_->cacheRawBlock(block, SdVolume::CACHE_FOR_WRITE)) goto fail;
        }
        uint8_t* dst = vol_->cache()->data + blockOffset;
        memcpy(dst, src, n);
      }
      curPosition_ += n;
      src += n;
      nToWrite -= n;
    }
    if (curPosition_ > fileSize_) {
      // update fileSize and insure sync will update dir entry
      fileSize_ = curPosition_;
      flags_ |= F_FILE_DIR_DIRTY;
    } else if (dateTime_ && nbyte) {
      // insure sync will update modified date and time
      flags_ |= F_FILE_DIR_DIRTY;
    }
  
    if (flags_ & O_SYNC) {
      if (!sync()) goto fail;
    }
    return nbyte;
  
   fail:
    // return for write error
    writeError = true;
    return -1;
  }
  //------------------------------------------------------------------------------
  // suppress cpplint warnings with NOLINT comment
  #if ALLOW_DEPRECATED_FUNCTIONS && !defined(DOXYGEN)
  void (*SdBaseFile::oldDateTime_)(uint16_t& date, uint16_t& time) = 0;  // NOLINT
  #endif  // ALLOW_DEPRECATED_FUNCTIONS
  
  
  #endif
  