SdBaseFile.cpp

/* 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"
#if ENABLED(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(fpos_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() {
  fpos_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.
 */