Rename to Sprinter

1 files changed, 1252 insertions, 0 deletions

diff --git a/Sprinter/SdFile.cpp b/Sprinter/SdFile.cpp
new file mode 100644
index 0000000..0a27159
--- /dev/null
+++ b/Sprinter/SdFile.cpp
@@ -0,0 +1,1252 @@
+/* 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 "SdFat.h"
+#include <avr/pgmspace.h>
+#include <WProgram.h>
+//------------------------------------------------------------------------------
+// callback function for date/time
+void (*SdFile::dateTime_)(uint16_t* date, uint16_t* time) = NULL;
+
+#if ALLOW_DEPRECATED_FUNCTIONS
+// suppress cpplint warnings with NOLINT comment
+void (*SdFile::oldDateTime_)(uint16_t& date, uint16_t& time) = NULL;  // NOLINT
+#endif  // ALLOW_DEPRECATED_FUNCTIONS
+//------------------------------------------------------------------------------
+// add a cluster to a file
+uint8_t SdFile::addCluster() {
+  if (!vol_->allocContiguous(1, &curCluster_)) return false;
+
+  // if first cluster of file link to directory entry
+  if (firstCluster_ == 0) {
+    firstCluster_ = curCluster_;
+    flags_ |= F_FILE_DIR_DIRTY;
+  }
+  return true;
+}
+//------------------------------------------------------------------------------
+// Add a cluster to a directory file and zero the cluster.
+// return with first block of cluster in the cache
+uint8_t SdFile::addDirCluster(void) {
+  if (!addCluster()) return false;
+
+  // zero data in cluster insure first cluster is in cache
+  uint32_t block = vol_->clusterStartBlock(curCluster_);
+  for (uint8_t i = vol_->blocksPerCluster_; i != 0; i--) {
+    if (!SdVolume::cacheZeroBlock(block + i - 1)) return false;
+  }
+  // Increase directory file size by cluster size
+  fileSize_ += 512UL << vol_->clusterSizeShift_;
+  return true;
+}
+//------------------------------------------------------------------------------
+// cache a file's directory entry
+// return pointer to cached entry or null for failure
+dir_t* SdFile::cacheDirEntry(uint8_t action) {
+  if (!SdVolume::cacheRawBlock(dirBlock_, action)) return NULL;
+  return SdVolume::cacheBuffer_.dir + dirIndex_;
+}
+//------------------------------------------------------------------------------
+/**
+ *  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.
+ */
+uint8_t SdFile::close(void) {
+  if (!sync())return false;
+  type_ = FAT_FILE_TYPE_CLOSED;
+  return true;
+}
+//------------------------------------------------------------------------------
+/**
+ * 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.
+ */
+uint8_t SdFile::contiguousRange(uint32_t* bgnBlock, uint32_t* endBlock) {
+  // error if no blocks
+  if (firstCluster_ == 0) return false;
+
+  for (uint32_t c = firstCluster_; ; c++) {
+    uint32_t next;
+    if (!vol_->fatGet(c, &next)) return false;
+
+    // check for contiguous
+    if (next != (c + 1)) {
+      // error if not end of chain
+      if (!vol_->isEOC(next)) return false;
+      *bgnBlock = vol_->clusterStartBlock(firstCluster_);
+      *endBlock = vol_->clusterStartBlock(c)
+                  + vol_->blocksPerCluster_ - 1;
+      return true;
+    }
+  }
+}
+//------------------------------------------------------------------------------
+/**
+ * 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] fileName 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 fileName 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.
+ *
+ */
+uint8_t SdFile::createContiguous(SdFile* dirFile,
+        const char* fileName, uint32_t size) {
+  // don't allow zero length file
+  if (size == 0) return false;
+  if (!open(dirFile, fileName, O_CREAT | O_EXCL | O_RDWR)) return false;
+
+  // calculate number of clusters needed
+  uint32_t count = ((size - 1) >> (vol_->clusterSizeShift_ + 9)) + 1;
+
+  // allocate clusters
+  if (!vol_->allocContiguous(count, &firstCluster_)) {
+    remove();
+    return false;
+  }
+  fileSize_ = size;
+
+  // insure sync() will update dir entry
+  flags_ |= F_FILE_DIR_DIRTY;
+  return sync();
+}
+//------------------------------------------------------------------------------
+/**
+ * Return a files directory entry
+ *
+ * \param[out] dir Location for return of the files directory entry.
+ *
+ * \return The value one, true, is returned for success and
+ * the value zero, false, is returned for failure.
+ */
+uint8_t SdFile::dirEntry(dir_t* dir) {
+  // make sure fields on SD are correct
+  if (!sync()) return false;
+
+  // read entry
+  dir_t* p = cacheDirEntry(SdVolume::CACHE_FOR_READ);
+  if (!p) return false;
+
+  // copy to caller's struct
+  memcpy(dir, p, sizeof(dir_t));
+  return true;
+}
+//------------------------------------------------------------------------------
+/**
+ * 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 SdFile::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;
+}
+//------------------------------------------------------------------------------
+/** List directory contents to Serial.
+ *
+ * \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 SdFile::ls(uint8_t flags, uint8_t indent) {
+  dir_t* p;
+
+  rewind();
+  while ((p = readDirCache())) {
+    // done if past last used entry
+    if (p->name[0] == DIR_NAME_FREE) break;
+
+    // skip deleted entry and entries for . and  ..
+    if (p->name[0] == DIR_NAME_DELETED || p->name[0] == '.') continue;
+
+    // only list subdirectories and files
+    if (!DIR_IS_FILE_OR_SUBDIR(p)) continue;
+
+    // print any indent spaces
+    for (int8_t i = 0; i < indent; i++) Serial.print(' ');
+
+    // print file name with possible blank fill
+    printDirName(*p, flags & (LS_DATE | LS_SIZE) ? 14 : 0);
+
+    // print modify date/time if requested
+    if (flags & LS_DATE) {
+       printFatDate(p->lastWriteDate);
+       Serial.print(' ');
+       printFatTime(p->lastWriteTime);
+    }
+    // print size if requested
+    if (!DIR_IS_SUBDIR(p) && (flags & LS_SIZE)) {
+      Serial.print(' ');
+      Serial.print(p->fileSize);
+    }
+    Serial.println();
+
+    // list subdirectory content if requested
+    if ((flags & LS_R) && DIR_IS_SUBDIR(p)) {
+      uint16_t index = curPosition()/32 - 1;
+      SdFile s;
+      if (s.open(this, index, O_READ)) s.ls(flags, indent + 2);
+      seekSet(32 * (index + 1));
+    }
+  }
+}
+//------------------------------------------------------------------------------
+// format directory name field from a 8.3 name string
+uint8_t SdFile::make83Name(const char* str, uint8_t* name) {
+  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 ((c = *str++) != '\0') {
+    if (c == '.') {
+      if (n == 10) return false;  // 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) return false;
+      // check size and only allow ASCII printable characters
+      if (i > n || c < 0X21 || c > 0X7E)return false;
+      // only upper case allowed in 8.3 names - convert lower to upper
+      name[i++] = c < 'a' || c > 'z' ?  c : c + ('A' - 'a');
+    }
+  }
+  // must have a file name, extension is optional
+  return name[0] != ' ';
+}
+//------------------------------------------------------------------------------
+/** Make a new directory.
+ *
+ * \param[in] dir An open SdFat instance for the directory that will containing
+ * the new directory.
+ *
+ * \param[in] dirName A valid 8.3 DOS name for the new directory.
+ *
+ * \return The value one, true, is returned for success and
+ * the value zero, false, is returned for failure.
+ * Reasons for failure include this SdFile is already open, \a dir is not a
+ * directory, \a dirName is invalid or already exists in \a dir.
+ */
+uint8_t SdFile::makeDir(SdFile* dir, const char* dirName) {
+  dir_t d;
+
+  // create a normal file
+  if (!open(dir, dirName, O_CREAT | O_EXCL | O_RDWR)) return false;
+
+  // convert SdFile to directory
+  flags_ = O_READ;
+  type_ = FAT_FILE_TYPE_SUBDIR;
+
+  // allocate and zero first cluster
+  if (!addDirCluster())return false;
+
+  // force entry to SD
+  if (!sync()) return false;
+
+  // cache entry - should already be in cache due to sync() call
+  dir_t* p = cacheDirEntry(SdVolume::CACHE_FOR_WRITE);
+  if (!p) return false;
+
+  // change directory entry  attribute
+  p->attributes = DIR_ATT_DIRECTORY;
+
+  // make entry for '.'
+  memcpy(&d, p, sizeof(d));
+  for (uint8_t i = 1; i < 11; i++) d.name[i] = ' ';
+  d.name[0] = '.';
+
+  // cache block for '.'  and '..'
+  uint32_t block = vol_->clusterStartBlock(firstCluster_);
+  if (!SdVolume::cacheRawBlock(block, SdVolume::CACHE_FOR_WRITE)) return false;
+
+  // copy '.' to block
+  memcpy(&SdVolume::cacheBuffer_.dir[0], &d, sizeof(d));
+
+  // make entry for '..'
+  d.name[1] = '.';
+  if (dir->isRoot()) {
+    d.firstClusterLow = 0;
+    d.firstClusterHigh = 0;
+  } else {
+    d.firstClusterLow = dir->firstCluster_ & 0XFFFF;
+    d.firstClusterHigh = dir->firstCluster_ >> 16;
+  }
+  // copy '..' to block
+  memcpy(&SdVolume::cacheBuffer_.dir[1], &d, sizeof(d));
+
+  // set position after '..'
+  curPosition_ = 2 * sizeof(d);
+
+  // write first block
+  return SdVolume::cacheFlush();
+}
+//------------------------------------------------------------------------------
+/**
+ * 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] fileName 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_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.
+ *
+ * \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 SdFile is already open, \a difFile is not
+ * a directory, \a fileName is invalid, the file does not exist
+ * or can't be opened in the access mode specified by oflag.
+ */
+uint8_t SdFile::open(SdFile* dirFile, const char* fileName, uint8_t oflag) {
+  uint8_t dname[11];
+  dir_t* p;
+
+  // error if already open
+  if (isOpen())return false;
+
+  if (!make83Name(fileName, dname)) return false;
+  vol_ = dirFile->vol_;
+  dirFile->rewind();
+
+  // bool for empty entry found
+  uint8_t emptyFound = false;
+
+  // search for file
+  while (dirFile->curPosition_ < dirFile->fileSize_) {
+    uint8_t index = 0XF & (dirFile->curPosition_ >> 5);
+    p = dirFile->readDirCache();
+    if (p == NULL) return false;
+
+    if (p->name[0] == DIR_NAME_FREE || p->name[0] == DIR_NAME_DELETED) {
+      // remember first empty slot
+      if (!emptyFound) {
+        emptyFound = true;
+        dirIndex_ = index;
+        dirBlock_ = SdVolume::cacheBlockNumber_;
+      }
+      // done if no entries follow
+      if (p->name[0] == DIR_NAME_FREE) break;
+    } else if (!memcmp(dname, p->name, 11)) {
+      // don't open existing file if O_CREAT and O_EXCL
+      if ((oflag & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) return false;
+
+      // open found file
+      return openCachedEntry(0XF & index, oflag);
+    }
+  }
+  // only create file if O_CREAT and O_WRITE
+  if ((oflag & (O_CREAT | O_WRITE)) != (O_CREAT | O_WRITE)) return false;
+
+  // cache found slot or add cluster if end of file
+  if (emptyFound) {
+    p = cacheDirEntry(SdVolume::CACHE_FOR_WRITE);
+    if (!p) return false;
+  } else {
+    if (dirFile->type_ == FAT_FILE_TYPE_ROOT16) return false;
+
+    // add and zero cluster for dirFile - first cluster is in cache for write
+    if (!dirFile->addDirCluster()) return false;
+
+    // use first entry in cluster
+    dirIndex_ = 0;
+    p = SdVolume::cacheBuffer_.dir;
+  }
+  // initialize as empty file
+  memset(p, 0, sizeof(dir_t));
+  memcpy(p->name, dname, 11);
+
+  // set timestamps
+  if (dateTime_) {
+    // call user 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;
+
+  // force write of entry to SD
+  if (!SdVolume::cacheFlush()) return false;
+
+  // open entry in cache
+  return openCachedEntry(dirIndex_, oflag);
+}
+//------------------------------------------------------------------------------
+/**
+ * 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 fileName for definition of flags and return values.
+ *
+ */
+uint8_t SdFile::open(SdFile* dirFile, uint16_t index, uint8_t oflag) {
+  // error if already open
+  if (isOpen())return false;
+
+  // don't open existing file if O_CREAT and O_EXCL - user call error
+  if ((oflag & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) return false;
+
+  vol_ = dirFile->vol_;
+
+  // seek to location of entry
+  if (!dirFile->seekSet(32 * index)) return false;
+
+  // read entry into cache
+  dir_t* p = dirFile->readDirCache();
+  if (p == NULL) return false;
+
+  // error if empty slot or '.' or '..'
+  if (p->name[0] == DIR_NAME_FREE ||
+      p->name[0] == DIR_NAME_DELETED || p->name[0] == '.') {
+    return false;
+  }
+  // open cached entry
+  return openCachedEntry(index & 0XF, oflag);
+}
+//------------------------------------------------------------------------------
+// open a cached directory entry. Assumes vol_ is initializes
+uint8_t SdFile::openCachedEntry(uint8_t dirIndex, uint8_t oflag) {
+  // location of entry in cache
+  dir_t* p = SdVolume::cacheBuffer_.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)) return false;
+  }
+  // remember location of directory entry on SD
+  dirIndex_ = dirIndex;
+  dirBlock_ = SdVolume::cacheBlockNumber_;
+
+  // 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_)) return false;
+    type_ = FAT_FILE_TYPE_SUBDIR;
+  } else {
+    return false;
+  }
+  // save open flags for read/write
+  flags_ = oflag & (O_ACCMODE | O_SYNC | O_APPEND);
+
+  // set to start of file
+  curCluster_ = 0;
+  curPosition_ = 0;
+
+  // truncate file to zero length if requested
+  if (oflag & O_TRUNC) return truncate(0);
+  return true;
+}
+//------------------------------------------------------------------------------
+/**
+ * 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 FAT volume has not been initialized
+ * or it a FAT12 volume.
+ */
+uint8_t SdFile::openRoot(SdVolume* vol) {
+  // error if file is already open
+  if (isOpen()) return false;
+
+  if (vol->fatType() == 16) {
+    type_ = FAT_FILE_TYPE_ROOT16;
+    firstCluster_ = 0;
+    fileSize_ = 32 * vol->rootDirEntryCount();
+  } else if (vol->fatType() == 32) {
+    type_ = FAT_FILE_TYPE_ROOT32;
+    firstCluster_ = vol->rootDirStart();
+    if (!vol->chainSize(firstCluster_, &fileSize_)) return false;
+  } else {
+    // volume is not initialized or FAT12
+    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;
+}
+//------------------------------------------------------------------------------
+/** %Print the name field of a directory entry in 8.3 format to Serial.
+ *
+ * \param[in] dir The directory structure containing the name.
+ * \param[in] width Blank fill name if length is less than \a width.
+ */
+void SdFile::printDirName(const dir_t& dir, uint8_t width) {
+  uint8_t w = 0;
+  for (uint8_t i = 0; i < 11; i++) {
+    if (dir.name[i] == ' ')continue;
+    if (i == 8) {
+      Serial.print('.');
+      w++;
+    }
+    Serial.print(dir.name[i]);
+    w++;
+  }
+  if (DIR_IS_SUBDIR(&dir)) {
+    Serial.print('/');
+    w++;
+  }
+  while (w < width) {
+    Serial.print(' ');
+    w++;
+  }
+}
+//------------------------------------------------------------------------------
+/** %Print a directory date field to Serial.
+ *
+ *  Format is yyyy-mm-dd.
+ *
+ * \param[in] fatDate The date field from a directory entry.
+ */
+void SdFile::printFatDate(uint16_t fatDate) {
+  Serial.print(FAT_YEAR(fatDate));
+  Serial.print('-');
+  printTwoDigits(FAT_MONTH(fatDate));
+  Serial.print('-');
+  printTwoDigits(FAT_DAY(fatDate));
+}
+//------------------------------------------------------------------------------
+/** %Print a directory time field to Serial.
+ *
+ * Format is hh:mm:ss.
+ *
+ * \param[in] fatTime The time field from a directory entry.
+ */
+void SdFile::printFatTime(uint16_t fatTime) {
+  printTwoDigits(FAT_HOUR(fatTime));
+  Serial.print(':');
+  printTwoDigits(FAT_MINUTE(fatTime));
+  Serial.print(':');
+  printTwoDigits(FAT_SECOND(fatTime));
+}
+//------------------------------------------------------------------------------
+/** %Print a value as two digits to Serial.
+ *
+ * \param[in] v Value to be printed, 0 <= \a v <= 99
+ */
+void SdFile::printTwoDigits(uint8_t v) {
+  char str[3];
+  str[0] = '0' + v/10;
+  str[1] = '0' + v % 10;
+  str[2] = 0;
+  Serial.print(str);
+}
+//------------------------------------------------------------------------------
+/**
+ * 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 SdFile::read(void* buf, uint16_t nbyte) {
+  uint8_t* dst = reinterpret_cast<uint8_t*>(buf);
+
+  // error if not open or write only
+  if (!isOpen() || !(flags_ & O_READ)) return -1;
+
+  // max bytes left in file
+  if (nbyte > (fileSize_ - curPosition_)) nbyte = fileSize_ - curPosition_;
+
+  // amount left to read
+  uint16_t toRead = nbyte;
+  while (toRead > 0) {
+    uint32_t block;  // raw device block number
+    uint16_t offset = curPosition_ & 0X1FF;  // offset in block
+    if (type_ == FAT_FILE_TYPE_ROOT16) {
+      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_)) return -1;
+        }
+      }
+      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 or user requests no buffering
+    if ((unbufferedRead() || n == 512) &&
+      block != SdVolume::cacheBlockNumber_) {
+      if (!vol_->readData(block, offset, n, dst)) return -1;
+      dst += n;
+    } else {
+      // read block to cache and copy data to caller
+      if (!SdVolume::cacheRawBlock(block, SdVolume::CACHE_FOR_READ)) return -1;
+      uint8_t* src = SdVolume::cacheBuffer_.data + offset;
+      uint8_t* end = src + n;
+      while (src != end) *dst++ = *src++;
+    }
+    curPosition_ += n;
+    toRead -= n;
+  }
+  return nbyte;
+}
+//------------------------------------------------------------------------------
+/**
+ * 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 SdFile::readDir(dir_t* dir) {
+  int8_t n;
+  // if not a directory file or miss-positioned return an error
+  if (!isDir() || (0X1F & curPosition_)) return -1;
+
+  while ((n = read(dir, sizeof(dir_t))) == sizeof(dir_t)) {
+    // last entry if DIR_NAME_FREE
+    if (dir->name[0] == DIR_NAME_FREE) break;
+    // skip empty entries and entry for .  and ..
+    if (dir->name[0] == DIR_NAME_DELETED || dir->name[0] == '.') continue;
+    // return if normal file or subdirectory
+    if (DIR_IS_FILE_OR_SUBDIR(dir)) return n;
+  }
+  // error, end of file, or past last entry
+  return n < 0 ? -1 : 0;
+}
+//------------------------------------------------------------------------------
+// Read next directory entry into the cache
+// Assumes file is correctly positioned
+dir_t* SdFile::readDirCache(void) {
+  // error if not directory
+  if (!isDir()) return NULL;
+
+  // index of entry in cache
+  uint8_t i = (curPosition_ >> 5) & 0XF;
+
+  // use read to locate and cache block
+  if (read() < 0) return NULL;
+
+  // advance to next entry
+  curPosition_ += 31;
+
+  // return pointer to entry
+  return (SdVolume::cacheBuffer_.dir + i);
+}
+//------------------------------------------------------------------------------
+/**
+ * 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.
+ */
+uint8_t SdFile::remove(void) {
+  // free any clusters - will fail if read-only or directory
+  if (!truncate(0)) return false;
+
+  // cache directory entry
+  dir_t* d = cacheDirEntry(SdVolume::CACHE_FOR_WRITE);
+  if (!d) return false;
+
+  // mark entry deleted
+  d->name[0] = DIR_NAME_DELETED;
+
+  // set this SdFile closed
+  type_ = FAT_FILE_TYPE_CLOSED;
+
+  // write entry to SD
+  return SdVolume::cacheFlush();
+}
+//------------------------------------------------------------------------------
+/**
+ * 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] fileName The name of 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 fileName is not found
+ * or an I/O error occurred.
+ */
+uint8_t SdFile::remove(SdFile* dirFile, const char* fileName) {
+  SdFile file;
+  if (!file.open(dirFile, fileName, O_WRITE)) return false;
+  return file.remove();
+}
+//------------------------------------------------------------------------------
+/** 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.
+ */
+uint8_t SdFile::rmDir(void) {
+  // must be open subdirectory
+  if (!isSubDir()) return false;
+
+  rewind();
+
+  // make sure directory is empty
+  while (curPosition_ < fileSize_) {
+    dir_t* p = readDirCache();
+    if (p == NULL) return false;
+    // done if past last used 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;
+    // error not empty
+    if (DIR_IS_FILE_OR_SUBDIR(p)) return false;
+  }
+  // convert empty directory to normal file for remove
+  type_ = FAT_FILE_TYPE_NORMAL;
+  flags_ |= O_WRITE;
+  return remove();
+}
+//------------------------------------------------------------------------------
+/** 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.
+ */
+uint8_t SdFile::rmRfStar(void) {
+  rewind();
+  while (curPosition_ < fileSize_) {
+    SdFile f;
+
+    // remember position
+    uint16_t index = curPosition_/32;
+
+    dir_t* p = readDirCache();
+    if (!p) return false;
+
+    // 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)) return false;
+    if (f.isSubDir()) {
+      // recursively delete
+      if (!f.rmRfStar()) return false;
+    } else {
+      // ignore read-only
+      f.flags_ |= O_WRITE;
+      if (!f.remove()) return false;
+    }
+    // position to next entry if required
+    if (curPosition_ != (32*(index + 1))) {
+      if (!seekSet(32*(index + 1))) return false;
+    }
+  }
+  // don't try to delete root
+  if (isRoot()) return true;
+  return rmDir();
+}
+//------------------------------------------------------------------------------
+/**
+ * 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.
+ */
+uint8_t SdFile::seekSet(uint32_t pos) {
+  // error if file not open or seek past end of file
+  if (!isOpen() || pos > fileSize_) return false;
+
+  if (type_ == FAT_FILE_TYPE_ROOT16) {
+    curPosition_ = pos;
+    return true;
+  }
+  if (pos == 0) {
+    // set position to start of file
+    curCluster_ = 0;
+    curPosition_ = 0;
+    return true;
+  }
+  // calculate cluster index for cur and new position
+  uint32_t nCur = (curPosition_ - 1) >> (vol_->clusterSizeShift_ + 9);
+  uint32_t 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_)) return false;
+  }
+  curPosition_ = pos;
+  return true;
+}
+//------------------------------------------------------------------------------
+/**
+ * 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.
+ */
+uint8_t SdFile::sync(void) {
+  // only allow open files and directories
+  if (!isOpen()) return false;
+
+  if (flags_ & F_FILE_DIR_DIRTY) {
+    dir_t* d = cacheDirEntry(SdVolume::CACHE_FOR_WRITE);
+    if (!d) return false;
+
+    // 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 SdVolume::cacheFlush();
+}
+//------------------------------------------------------------------------------
+/**
+ * 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.
+ */
+uint8_t SdFile::timestamp(uint8_t flags, uint16_t year, uint8_t month,
+         uint8_t day, uint8_t hour, uint8_t minute, uint8_t second) {
+  if (!isOpen()
+    || year < 1980
+    || year > 2107
+    || month < 1
+    || month > 12
+    || day < 1
+    || day > 31
+    || hour > 23
+    || minute > 59
+    || second > 59) {
+      return false;
+  }
+  dir_t* d = cacheDirEntry(SdVolume::CACHE_FOR_WRITE);
+  if (!d) return false;
+
+  uint16_t dirDate = FAT_DATE(year, month, day);
+  uint16_t 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;
+  }
+  SdVolume::cacheSetDirty();
+  return sync();
+}
+//------------------------------------------------------------------------------
+/**
+ * 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.
+ */
+uint8_t SdFile::truncate(uint32_t length) {
+// error if not a normal file or read-only
+  if (!isFile() || !(flags_ & O_WRITE)) return false;
+
+  // error if length is greater than current size
+  if (length > fileSize_) return false;
+
+  // fileSize and length are zero - nothing to do
+  if (fileSize_ == 0) return true;
+
+  // remember position for seek after truncation
+  uint32_t newPos = curPosition_ > length ? length : curPosition_;
+
+  // position to last cluster in truncated file
+  if (!seekSet(length)) return false;
+
+  if (length == 0) {
+    // free all clusters
+    if (!vol_->freeChain(firstCluster_)) return false;
+    firstCluster_ = 0;
+  } else {
+    uint32_t toFree;
+    if (!vol_->fatGet(curCluster_, &toFree)) return false;
+
+    if (!vol_->isEOC(toFree)) {
+      // free extra clusters
+      if (!vol_->freeChain(toFree)) return false;
+
+      // current cluster is end of chain
+      if (!vol_->fatPutEOC(curCluster_)) return false;
+    }
+  }
+  fileSize_ = length;
+
+  // need to update directory entry
+  flags_ |= F_FILE_DIR_DIRTY;
+
+  if (!sync()) return false;
+
+  // set file to correct position
+  return seekSet(newPos);
+}
+//------------------------------------------------------------------------------
+/**
+ * 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 SdFile::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 writeErrorReturn;
+
+  // seek to end of file if append flag
+  if ((flags_ & O_APPEND) && curPosition_ != fileSize_) {
+    if (!seekEnd()) goto writeErrorReturn;
+  }
+
+  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 writeErrorReturn;
+        } else {
+          curCluster_ = firstCluster_;
+        }
+      } else {
+        uint32_t next;
+        if (!vol_->fatGet(curCluster_, &next)) return false;
+        if (vol_->isEOC(next)) {
+          // add cluster if at end of chain
+          if (!addCluster()) goto writeErrorReturn;
+        } 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
+      // invalidate cache if block is in cache
+      if (SdVolume::cacheBlockNumber_ == block) {
+        SdVolume::cacheBlockNumber_ = 0XFFFFFFFF;
+      }
+      if (!vol_->writeBlock(block, src)) goto writeErrorReturn;
+      src += 512;
+    } else {
+      if (blockOffset == 0 && curPosition_ >= fileSize_) {
+        // start of new block don't need to read into cache
+        if (!SdVolume::cacheFlush()) goto writeErrorReturn;
+        SdVolume::cacheBlockNumber_ = block;
+        SdVolume::cacheSetDirty();
+      } else {
+        // rewrite part of block
+        if (!SdVolume::cacheRawBlock(block, SdVolume::CACHE_FOR_WRITE)) {
+          goto writeErrorReturn;
+        }
+      }
+      uint8_t* dst = SdVolume::cacheBuffer_.data + blockOffset;
+      uint8_t* end = dst + n;
+      while (dst != end) *dst++ = *src++;
+    }
+    nToWrite -= n;
+    curPosition_ += 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 writeErrorReturn;
+  }
+  return nbyte;
+
+ writeErrorReturn:
+  // return for write error
+  writeError = true;
+  return -1;
+}
+//------------------------------------------------------------------------------
+/**
+ * Write a byte to a file. Required by the Arduino Print class.
+ *
+ * Use SdFile::writeError to check for errors.
+ */
+void SdFile::write(uint8_t b) {
+  write(&b, 1);
+}
+//------------------------------------------------------------------------------
+/**
+ * Write a string to a file. Used by the Arduino Print class.
+ *
+ * Use SdFile::writeError to check for errors.
+ */
+void SdFile::write(const char* str) {
+  write(str, strlen(str));
+}
+//------------------------------------------------------------------------------
+/**
+ * Write a PROGMEM string to a file.
+ *
+ * Use SdFile::writeError to check for errors.
+ */
+void SdFile::write_P(PGM_P str) {
+  for (uint8_t c; (c = pgm_read_byte(str)); str++) write(c);
+}
+//------------------------------------------------------------------------------
+/**
+ * Write a PROGMEM string followed by CR/LF to a file.
+ *
+ * Use SdFile::writeError to check for errors.
+ */
+void SdFile::writeln_P(PGM_P str) {
+  write_P(str);
+  println();
+}