C++ SdFile::open方法代码示例

File SDClass::open(const char *filepath, uint8_t mode) {
  /*

     Open the supplied file path for reading or writing.

     The file content can be accessed via the `file` property of
     the `SDClass` object--this property is currently
     a standard `SdFile` object from `sdfatlib`.

     Defaults to read only.

     If `write` is true, default action (when `append` is true) is to
     append data to the end of the file.

     If `append` is false then the file will be truncated first.

     If the file does not exist and it is opened for writing the file
     will be created.

     An attempt to open a file for reading that does not exist is an
     error.

   */

  int pathidx;

  // do the interative search
  SdFile parentdir = getParentDir(filepath, &pathidx);
  // no more subdirs!

  filepath += pathidx;

  if (! filepath[0]) {
    // it was the directory itself!
    return File(parentdir, "/");
  }

  // Open the file itself
  SdFile file;

  // failed to open a subdir!
  if (!parentdir.isOpen())
    return File();

  // there is a special case for the Root directory since its a static dir
  if (parentdir.isRoot()) {
    if ( ! file.open(SD.root, filepath, mode)) {
      // failed to open the file :(
      return File();
    }
    // dont close the root!
  } else {
    if ( ! file.open(parentdir, filepath, mode)) {
      return File();
    }
    // close the parent
    parentdir.close();
  }

  if (mode & O_APPEND & O_WRITE) 
    file.seekSet(file.fileSize());
  return File(file, filepath);
}

void CardReader::removeFile(char* name)
{
  if(!cardOK)
    return;
  file.close();
  sdprinting = false;
  
  
  SdFile myDir;
  curDir=&root;
  char *fname=name;
  
  char *dirname_start,*dirname_end;
  if(name[0]=='/')
  {
    dirname_start=strchr(name,'/')+1;
    while(dirname_start>0)
    {
      dirname_end=strchr(dirname_start,'/');
      //SERIAL_ECHO("start:");SERIAL_ECHOLN((int)(dirname_start-name));
      //SERIAL_ECHO("end  :");SERIAL_ECHOLN((int)(dirname_end-name));
      if(dirname_end>0 && dirname_end>dirname_start)
      {
        char subdirname[13];
        strncpy(subdirname, dirname_start, dirname_end-dirname_start);
        subdirname[dirname_end-dirname_start]=0;
        SERIAL_ECHOLN(subdirname);
        if(!myDir.open(curDir,subdirname,O_READ))
        {
          SERIAL_PROTOCOLPGM("open failed, File: ");
          SERIAL_PROTOCOL(subdirname);
          SERIAL_PROTOCOLLNPGM(".");
          return;
        }
        else
        {
          //SERIAL_ECHOLN("dive ok");
        }
          
        curDir=&myDir; 
        dirname_start=dirname_end+1;
      }
      else // the reminder after all /fsa/fdsa/ is the filename
      {
        fname=dirname_start;
        //SERIAL_ECHOLN("remaider");
        //SERIAL_ECHOLN(fname);
        break;
      }
      
    }
  }
  else //relative path
  {
    curDir=&workDir;
  }
    if (file.remove(curDir, fname)) 
    {
      SERIAL_PROTOCOLPGM("File deleted:");
      SERIAL_PROTOCOL(fname);
      sdpos = 0;
    }
    else
    {
      SERIAL_PROTOCOLPGM("Deletion failed, File: ");
      SERIAL_PROTOCOL(fname);
      SERIAL_PROTOCOLLNPGM(".");
    }
  
}

void  CardReader::lsDive(const char *prepend,SdFile parent)
{
  dir_t p;
 uint8_t cnt=0;
 
  while (parent.readDir(p, longFilename) > 0)
  {
    if( DIR_IS_SUBDIR(&p) && lsAction!=LS_Count && lsAction!=LS_GetFilename) // hence LS_SerialPrint
    {

      char path[13*2];
      char lfilename[13];
      createFilename(lfilename,p);
      
      path[0]=0;
      if(strlen(prepend)==0) //avoid leading / if already in prepend
      {
       strcat(path,"/");
      }
      strcat(path,prepend);
      strcat(path,lfilename);
      strcat(path,"/");
      
      //Serial.print(path);
      
      SdFile dir;
      if(!dir.open(parent,lfilename, O_READ))
      {
        if(lsAction==LS_SerialPrint)
        {
          SERIAL_ECHO_START;
          SERIAL_ECHOLN(MSG_SD_CANT_OPEN_SUBDIR);
          SERIAL_ECHOLN(lfilename);
        }
      }
      lsDive(path,dir);
      //close done automatically by destructor of SdFile

      
    }
    else
    {
      if (p.name[0] == DIR_NAME_FREE) break;
      if (p.name[0] == DIR_NAME_DELETED || p.name[0] == '.'|| p.name[0] == '_') continue;
      if (longFilename[0] != '\0' &&
          (longFilename[0] == '.' || longFilename[0] == '_')) continue;
      if ( p.name[0] == '.')
      {
        if ( p.name[1] != '.')
        continue;
      }
      
      if (!DIR_IS_FILE_OR_SUBDIR(&p)) continue;
      filenameIsDir=DIR_IS_SUBDIR(&p);
      
      
      if(!filenameIsDir)
      {
        if(p.name[8]!='G') continue;
        if(p.name[9]=='~') continue;
      }
      //if(cnt++!=nr) continue;
      createFilename(filename,p);
      if(lsAction==LS_SerialPrint)
      {
        SERIAL_PROTOCOL(prepend);
        SERIAL_PROTOCOLLN(filename);
      }
      else if(lsAction==LS_Count)
      {
        nrFiles++;
      } 
      else if(lsAction==LS_GetFilename)
      {
        if(cnt==nrFiles)
          return;
        cnt++;
        
      }
    }
  }
}

void CardReader::openFile(char* name,bool read)
{
  if(!cardOK)
    return;
  file.close();
  sdprinting = false;
  
  
  SdFile myDir;
  curDir=&root;
  char *fname=name;
  
  char *dirname_start,*dirname_end;
  if(name[0]=='/')
  {
    dirname_start=strchr(name,'/')+1;
    while(dirname_start>0)
    {
      dirname_end=strchr(dirname_start,'/');
      //SERIAL_ECHO("start:");SERIAL_ECHOLN((int)(dirname_start-name));
      //SERIAL_ECHO("end  :");SERIAL_ECHOLN((int)(dirname_end-name));
      if(dirname_end>0 && dirname_end>dirname_start)
      {
        char subdirname[13];
        strncpy(subdirname, dirname_start, dirname_end-dirname_start);
        subdirname[dirname_end-dirname_start]=0;
        SERIAL_ECHOLN(subdirname);
        if(!myDir.open(curDir,subdirname,O_READ))
        {
          SERIAL_PROTOCOLPGM(MSG_SD_OPEN_FILE_FAIL);
          SERIAL_PROTOCOL(subdirname);
          SERIAL_PROTOCOLLNPGM(".");
          return;
        }
        else
        {
          //SERIAL_ECHOLN("dive ok");
        }
          
        curDir=&myDir; 
        dirname_start=dirname_end+1;
      }
      else // the reminder after all /fsa/fdsa/ is the filename
      {
        fname=dirname_start;
        //SERIAL_ECHOLN("remaider");
        //SERIAL_ECHOLN(fname);
        break;
      }
      
    }
  }
  else //relative path
  {
    curDir=&workDir;
  }
  if(read)
  {
    if (file.open(curDir, fname, O_READ)) 
    {
      filesize = file.fileSize();
      SERIAL_PROTOCOLPGM(MSG_SD_FILE_OPENED);
      SERIAL_PROTOCOL(fname);
      SERIAL_PROTOCOLPGM(MSG_SD_SIZE);
      SERIAL_PROTOCOLLN(filesize);
      sdpos = 0;
      
      SERIAL_PROTOCOLLNPGM(MSG_SD_FILE_SELECTED);
      lcd_setstatus(fname);
    }
    else
    {
      SERIAL_PROTOCOLPGM(MSG_SD_OPEN_FILE_FAIL);
      SERIAL_PROTOCOL(fname);
      SERIAL_PROTOCOLLNPGM(".");
    }
  }
  else 
  { //write
    if (!file.open(curDir, fname, O_CREAT | O_APPEND | O_WRITE | O_TRUNC))
    {
      SERIAL_PROTOCOLPGM(MSG_SD_OPEN_FILE_FAIL);
      SERIAL_PROTOCOL(fname);
      SERIAL_PROTOCOLLNPGM(".");
    }
    else
    {
      saving = true;
      SERIAL_PROTOCOLPGM(MSG_SD_WRITE_TO_FILE);
      SERIAL_PROTOCOLLN(name);
      lcd_setstatus(fname);
    }
  }
  
}

void CardReader::openFile(char* name,bool read, bool replace_current/*=true*/)
{
  if(!cardOK)
    return;
  if(file.isOpen())  //replacing current file by new file, or subfile call
  {
    if(!replace_current)
    {
     if((int)file_subcall_ctr>(int)SD_PROCEDURE_DEPTH-1)
     {
       SERIAL_ERROR_START;
       SERIAL_ERRORPGM("trying to call sub-gcode files with too many levels. MAX level is:");
       SERIAL_ERRORLN(SD_PROCEDURE_DEPTH);
       kill();
       return;
     }
     
     SERIAL_ECHO_START;
     SERIAL_ECHOPGM("SUBROUTINE CALL target:\"");
     SERIAL_ECHO(name);
     SERIAL_ECHOPGM("\" parent:\"");
     
     //store current filename and position
     getAbsFilename(filenames[file_subcall_ctr]);
     
     SERIAL_ECHO(filenames[file_subcall_ctr]);
     SERIAL_ECHOPGM("\" pos");
     SERIAL_ECHOLN(sdpos);
     filespos[file_subcall_ctr]=sdpos;
     file_subcall_ctr++;
    }
    else
    {
     SERIAL_ECHO_START;
     SERIAL_ECHOPGM("Now doing file: ");
     SERIAL_ECHOLN(name);
    }
    file.close();
  }
  else //opening fresh file
  {
    file_subcall_ctr=0; //resetting procedure depth in case user cancels print while in procedure
    SERIAL_ECHO_START;
    SERIAL_ECHOPGM("Now fresh file: ");
    SERIAL_ECHOLN(name);
  }
  sdprinting = false;
  
 
  SdFile myDir;
  curDir=&root;
  char *fname=name;
  
  char *dirname_start,*dirname_end;
  if(name[0]=='/')
  {
    dirname_start=strchr(name,'/')+1;
    while(dirname_start>0)
    {
      dirname_end=strchr(dirname_start,'/');
      //SERIAL_ECHO("start:");SERIAL_ECHOLN((int)(dirname_start-name));
      //SERIAL_ECHO("end  :");SERIAL_ECHOLN((int)(dirname_end-name));
      if(dirname_end>0 && dirname_end>dirname_start)
      {
        char subdirname[13];
        strncpy(subdirname, dirname_start, dirname_end-dirname_start);
        subdirname[dirname_end-dirname_start]=0;
        SERIAL_ECHOLN(subdirname);
        if(!myDir.open(curDir,subdirname,O_READ))
        {
          SERIAL_PROTOCOLPGM(MSG_SD_OPEN_FILE_FAIL);
          SERIAL_PROTOCOL(subdirname);
          SERIAL_PROTOCOLLNPGM(".");
          return;
        }
        else
        {
          //SERIAL_ECHOLN("dive ok");
        }
          
        curDir=&myDir; 
        dirname_start=dirname_end+1;
      }
      else // the reminder after all /fsa/fdsa/ is the filename
      {
        fname=dirname_start;
        //SERIAL_ECHOLN("remaider");
        //SERIAL_ECHOLN(fname);
        break;
      }
      
    }
  }
  else //relative path
  {
    curDir=&workDir;
  }
  if(read)
  {
    if (file.open(curDir, fname, O_READ)) 
//.........这里部分代码省略.........

void setup() 
{
  Serial.begin(BPS_115200);
  Serial.println("> type any char to start");
  while (!Serial.available());
  Serial.println();

  if (!card.init(SPI_HALF_SPEED)) 
    Serial.println("> card.init failed");
  else
    Serial.println("> card.init passed");
//  spi.end();
  
  SD_SPI.begin(SPI_HIGH_CLOCK, MSBFIRST, 0);
  
  delay(100);
  
  // initialize a FAT volume
  if (!volume.init(&card,1)) 
    Serial.println("> volume.init failed");
  else
    Serial.println("> volume.init passed");
    
  // open the root directory
  if (!root.openRoot(&volume)) 
    Serial.println("> openRoot failed");
  else
    Serial.println("> openRoot passed");

  // open a file
  if (file.open(&root, "Read.txt", O_READ)) 
  {
    Serial.println("> Opened Read.txt");
    Serial.println("> Reading ...");
    Serial.println();
    for(int i=0; i<15; i++)
      Serial.print((char)file.read());
    Serial.println("");
  }
  else
  {
    Serial.println("file.open failed");
  }
  Serial.println();  
  Serial.println("> Reading remained data...");
  Serial.println();  
  int16_t n;
  uint8_t buf[7];// nothing special about 7, just a lucky number.
  while ((n = file.read(buf, sizeof(buf))) > 0) 
  {
    for (uint8_t i = 0; i < n; i++) 
      Serial.print((char)buf[i]);
  }
  /* easier way
  int16_t c;
  while ((c = file.read()) > 0) Serial.print((char)c);
  */
  file.close();
  Serial.println("\n> Done");
  SD_SPI.end();
  
}

void writeGPSLog(uint32_t gpstime, int32_t latitude, int32_t longitude, int32_t altitude) {
#else
void writeGPSLog(int32_t latitude, int32_t longitude, int32_t altitude) {
#endif
if (f.SDCARD == 0) return;
  if (gps_data.open(GPS_LOG_FILENAME, O_WRITE | O_CREAT | O_APPEND)) {
#ifdef UBLOX  
    gps_data.print(gpstime); gps_data.write(',');
#endif
    gps_data.print(latitude); gps_data.write(',');
    gps_data.print(longitude); gps_data.write(',');
    gps_data.print(altitude); gps_data.println();
    gps_data.close();
  } else { 
    return;
  }
}

void writePLogToSD() {
  if (f.SDCARD == 0) return;
  plog.checksum = calculate_sum((uint8_t*)&plog, sizeof(plog));
  if (permanent.open(PERMANENT_LOG_FILENAME, O_WRITE | O_CREAT | O_TRUNC)) {
    permanent.print(F("arm=")); permanent.println(plog.arm);
    permanent.print(F("disarm=")); permanent.println(plog.disarm);
    permanent.print(F("start=")); permanent.println(plog.start);
    permanent.print(F("armed_time=")); permanent.println(plog.armed_time);
    permanent.print(F("lifetime=")); permanent.println(plog.lifetime, DEC);
    permanent.print(F("failsafe=")); permanent.println(plog.failsafe);
    permanent.print(F("i2c=")); permanent.println(plog.i2c);
    permanent.print(F("running=")); permanent.println(plog.running, DEC);
    permanent.print(F("checksum=")); permanent.println(plog.checksum, DEC);
    permanent.print(F("debug=")); permanent.print(debug[0]);
    permanent.print(F(",")); permanent.print(debug[1]);
    permanent.print(F(",")); permanent.print(debug[2]);
    permanent.print(F(",")); permanent.println(debug[3]);
    permanent.println();
    permanent.close();
  } else { 
    return;
  }
}

void fillPlogStruct(char* key, char* value) {
  if (strcmp(key, "arm") == 0) sscanf(value, "%u", &plog.arm);
  if (strcmp(key, "disarm") == 0) sscanf(value, "%u", &plog.disarm);
  if (strcmp(key, "start") == 0) sscanf(value, "%u", &plog.start);
  if (strcmp(key, "armed_time") == 0) sscanf(value, "%lu", &plog.armed_time);
  if (strcmp(key, "lifetime") == 0) sscanf(value, "%lu", &plog.lifetime);
  if (strcmp(key, "failsafe") == 0) sscanf(value, "%u", &plog.failsafe);
  if (strcmp(key, "i2c") == 0) sscanf(value, "%u", &plog.i2c);
  if (strcmp(key, "running") == 0) sscanf(value, "%hhu", &plog.running);
  if (strcmp(key, "checksum") == 0) sscanf(value, "%hhu", &plog.checksum);
}

void readPLogFromSD() {
  if (f.SDCARD == 0) return;
  SdFile myfile;
  char key[12];
  char value[32];
  char* tabPtr = key;
  int c;
  uint8_t i = 0;
   
  if (myfile.open(PERMANENT_LOG_FILENAME, O_READ)) {
    while (myfile.available()) {
      c = myfile.read();
      switch ((char)c) {
        case ' ':
          break;
        case '=':
          *tabPtr = '\0';
          tabPtr = value;
          break;  
        case '\n':
          *tabPtr = '\0';
          tabPtr = key;
          i = 0;
          fillPlogStruct(key, value);
          memset(key, '\0', sizeof(key));
          memset(value, '\0', sizeof(value));
          break;
        default:
          i++;
          if (i <= 12) {
            *tabPtr = (char)c;
            tabPtr++;
          }
          break;
        }
    }
  } else return;
  if (calculate_sum((uint8_t*)&plog, sizeof(plog)) != plog.checksum) {
#if defined(BUZZER)
    alarmArray[7] = 3;
    blinkLED(9, 100, 3);
#endif
    // force load defaults
    plog.arm = plog.disarm = plog.start = plog.failsafe = plog.i2c = 11;
    plog.running = 1;
    plog.lifetime = plog.armed_time = 3;
//.........这里部分代码省略.........

//.........这里部分代码省略.........
		} else {
			Serial.println("Not Connected to HMC5883L.");
		}
	#endif
	error = compass.SetScale(1.3); 				// Set the scale of the compass.
	#ifdef DEBUG_ON	
		if(error != 0) {							// If there is an error, print it out.
			Serial.println("Compass Error 1");
			Serial.println(compass.GetErrorText(error));
		} else {
			Serial.println("Compass Ok 1");
		}
	#endif
	error = compass.SetMeasurementMode(Measurement_Continuous); // Set the measurement mode to Continuous
	#ifdef DEBUG_ON	
		if(error != 0) {							// If there is an error, print it out.
			Serial.println("Compass error 2");
			Serial.println(compass.GetErrorText(error));
		} else {
			Serial.println("Compass Ok 2");
		}
	#endif	
	
	//Start up the Pressure Sensor
	dps = BMP085();
	dps.init(); 
	#ifdef DEBUG_ON
		Serial.print("BMP Mode ");
		Serial.println(dps.getMode());
	#endif	
	wdt_reset();
	// Start up the OneWire Sensors library and turn off blocking takes too long!
	sensors.begin();
	sensors.setWaitForConversion(false);
  	sensors.requestTemperaturesByAddress(outsideThermometer); // Send the command to get temperature
	
	//Initialise all of the record values
	mD.vals.tCount = 0;
	mD.vals.uslCount = 0;
	mD.vals.year = 0;
	mD.vals.month = 0;
	mD.vals.day = 0;
	mD.vals.hour = 0;
	mD.vals.minute = 0;
	mD.vals.second = 0;
	mD.vals.hundredths = 0;
	mD.vals.iLat = 0;
	mD.vals.iLong = 0;
	mD.vals.iAlt = 0;
	mD.vals.bSats = 0;
	mD.vals.iAngle = 0;
	mD.vals.iHspeed = 0;
	mD.vals.iVspeed = 0;
	mD.vals.age = 0;
	mD.vals.ihdop = 0;
	mD.vals.AcXPayload = 0;
	mD.vals.AcYPayload = 0;
	mD.vals.AcZPayload = 0;
	mD.vals.GyXPayload = 0;
	mD.vals.GyYPayload = 0;
	mD.vals.GyZPayload = 0;
	mD.vals.MgXPayload = 0;
	mD.vals.MgYPayload = 0;
	mD.vals.MgZPayload = 0;
	mD.vals.TmpPayload = 0;
	
	//Connect to the SD Card	
	if(!SD.begin(PIN_SPI_CS, SPI_HALF_SPEED)) {
		#ifdef DEBUG_ON	
			Serial.println("SD not working!!");
		#endif 
		SET_LED_Status(SET_LED_WHITE,500); 	//White LED
		SET_LED_Status(SET_LED_RED,3000); 	//Red LED 
	} else {
		#ifdef DEBUG_ON	
			Serial.println("SD OK");
		#endif 	
		dataFile.open(SD_LOG_FILE, O_CREAT | O_WRITE | O_APPEND);	    //Open Logfile
		if (!dataFile.isOpen()) {
			#ifdef DEBUG_ON	
				Serial.println("SD Data File Not Opened");
			#endif 	
			SET_LED_Status(SET_LED_WHITE,500);
			SET_LED_Status(SET_LED_RED,3000);
		}
	}

	//Cycle lights
	SET_LED_Status(SET_LED_OFF,0);  
	SET_LED_Status(SET_LED_RED,500);
	SET_LED_Status(SET_LED_GREEN,500);
	SET_LED_Status(SET_LED_BLUE,500);
	SET_LED_Status(SET_LED_OFF,0);  
	
	elapseSIM900 = millis();				//Elapse counter for data to SIM900
	elapseNTXB = millis();					//Elapse counter for data to NTXB
	NEWGPSDATA = false;
	wdt_enable(WDTO_2S);
	wdt_reset();
}

//------------------------------------------------------------------------------
void setup() {
  Serial.begin(9600);
  
  // Wait for USB Serial 
  while (!Serial) {
    SysCall::yield();
  }
  delay(1000);

  cout << F("Type any character to start\n");
  // Wait for input line and discard.
  cin.readline();
  cout << endl;
  
  // Initialize the SD card at SPI_HALF_SPEED to avoid bus errors with
  // breadboards.  use SPI_FULL_SPEED for better performance.
  if (!sd.begin(SD_CHIP_SELECT, SPI_HALF_SPEED)) {
    sd.initErrorHalt();
  }
  if (sd.exists("Folder1") 
    || sd.exists("Folder1/file1.txt")
    || sd.exists("Folder1/File2.txt")) {
    error("Please remove existing Folder1, file1.txt, and File2.txt");
  }
  int rootFileCount = 0;
  sd.vwd()->rewind();   
  while (file.openNext(sd.vwd(), O_READ)) {
    if (!file.isHidden()) {
      rootFileCount++;
    }
    file.close();
    if (rootFileCount > 10) {
      error("Too many files in root. Please use an empty SD.");
    }
  }
  if (rootFileCount) {
    cout << F("\nPlease use an empty SD for best results.\n\n");
    delay(1000);    
  }
  // Create a new folder.
  if (!sd.mkdir("Folder1")) {
    error("Create Folder1 failed");
  }
  cout << F("Created Folder1\n");

  // Create a file in Folder1 using a path.
  if (!file.open("Folder1/file1.txt", O_CREAT | O_WRITE)) {
    error("create Folder1/file1.txt failed");
  }
  file.close();
  cout << F("Created Folder1/file1.txt\n");

  // Change volume working directory to Folder1.
  if (!sd.chdir("Folder1")) {
    error("chdir failed for Folder1.\n");
  }
  cout << F("chdir to Folder1\n");

  // Create File2.txt in current directory.
  if (!file.open("File2.txt", O_CREAT | O_WRITE)) {
    error("create File2.txt failed");
  }
  file.close();
  cout << F("Created File2.txt in current directory\n");

  cout << F("\nList of files on the SD.\n");
  sd.ls("/", LS_R);

  // Remove files from current directory.
  if (!sd.remove("file1.txt") || !sd.remove("File2.txt")) {
    error("remove failed");
  }
  cout << F("\nfile1.txt and File2.txt removed.\n");

  // Change current directory to root.
  if (!sd.chdir()) {
    error("chdir to root failed.\n");
  }

  cout << F("\nList of files on the SD.\n");
  sd.ls(LS_R);

  // Remove Folder1.
  if (!sd.rmdir("Folder1")) {
    error("rmdir for Folder1 failed\n");
  }

  cout << F("\nFolder1 removed.\n");
  cout << F("\nList of files on the SD.\n");
  sd.ls(LS_R);
  cout << F("Done!\n");
}

uint32_t SDCard_FileHandler::fileSize(String file){
    SdFile myFile; myFile.open(file);
    auto size = myFile.fileSize();
    return size;
}

/**
 * Dive into a folder and recurse depth-first to perform a pre-set operation lsAction:
 *   LS_Count       - Add +1 to nrFiles for every file within the parent
 *   LS_GetFilename - Get the filename of the file indexed by nrFiles
 *   LS_SerialPrint - Print the full path of each file to serial output
 */
void CardReader::lsDive(const char* prepend, SdFile parent, const char* const match/*=NULL*/) {
  dir_t p;
  uint8_t cnt = 0;
  // Read the next entry from a directory
  while (parent.readDir(p, longFilename) > 0) {
    // If the entry is a directory and the action is LS_SerialPrint
    if (DIR_IS_SUBDIR(&p) && lsAction != LS_Count && lsAction != LS_GetFilename) {
      // Get the short name for the item, which we know is a folder
      char lfilename[FILENAME_LENGTH];
      createFilename(lfilename, p);
      // Allocate enough stack space for the full path to a folder, trailing slash, and nul
      boolean prepend_is_empty = (prepend[0] == '\0');
      int len = (prepend_is_empty ? 1 : strlen(prepend)) + strlen(lfilename) + 1 + 1;
      char path[len];
      // Append the FOLDERNAME12/ to the passed string.
      // It contains the full path to the "parent" argument.
      // We now have the full path to the item in this folder.
      strcpy(path, prepend_is_empty ? "/" : prepend); // root slash if prepend is empty
      strcat(path, lfilename); // FILENAME_LENGTH-1 characters maximum
      strcat(path, "/");       // 1 character
      // Serial.print(path);
      // Get a new directory object using the full path
      // and dive recursively into it.
      SdFile dir;
      if (!dir.open(parent, lfilename, O_READ)) {
        if (lsAction == LS_SerialPrint) {
          SERIAL_ECHO_START;
          SERIAL_ECHOLN(MSG_SD_CANT_OPEN_SUBDIR);
          SERIAL_ECHOLN(lfilename);
        }
      }
      lsDive(path, dir);
      // close() is done automatically by destructor of SdFile
    } else {
      char pn0 = p.name[0];
      if (pn0 == DIR_NAME_FREE) break;
      if (pn0 == DIR_NAME_DELETED || pn0 == '.') continue;
      if (longFilename[0] == '.') continue;
      if (!DIR_IS_FILE_OR_SUBDIR(&p)) continue;
      filenameIsDir = DIR_IS_SUBDIR(&p);
      if (!filenameIsDir && (p.name[8] != 'G' || p.name[9] == '~')) continue;
      switch (lsAction) {
      case LS_Count:
        nrFiles++;
        break;
      case LS_SerialPrint:
        createFilename(filename, p);
        SERIAL_PROTOCOL(prepend);
        SERIAL_PROTOCOLLN(filename);
        break;
      case LS_GetFilename:
        createFilename(filename, p);
        if (match != NULL) {
          if (strcasecmp(match, filename) == 0) return;
        } else if (cnt == nrFiles) return;
        cnt++;
        break;
      }
    }
  } // while readDir
}