/*
 * Append Example
 *
 * This sketch shows how to use open for append and the Arduino Print class
 * with SdFat.
 */
#include <SdFat.h>
#include <SdFatUtil.h> // use functions to print strings from flash memory

const uint8_t SD_CHIP_SELECT = SS;

SdFat sd;

SdFile file;

// store error strings in flash to save RAM
#define error(s) sd.errorHalt_P(PSTR(s))
//------------------------------------------------------------------------------
void setup(void) {
  Serial.begin(9600);
  while (!Serial) {}  // wait for Leonardo
  PgmPrintln("Type any character to start");
  while (Serial.read() <= 0) {}
  delay(200);  // Catch Due reset problem
  
  // 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();

  char name[] = "APPEND.TXT";
  PgmPrint("Appending to: ");
  Serial.println(name);
  
  for (uint8_t i = 0; i < 100; i++) {
    // O_CREAT - create the file if it does not exist
    // O_APPEND - seek to the end of the file prior to each write
    // O_WRITE - open for write
    if (!file.open(name, O_CREAT | O_APPEND | O_WRITE)) {
      error("open failed");
    }
    // print 100 lines to file
    for (uint8_t j = 0; j < 100; j++) {
      file.print("line ");
      file.print(j, DEC);
      file.print(" of pass ");
      file.print(i, DEC);
      file.print(" millis = ");
      file.println(millis());
    }
    if (file.writeError) error("write failed");
    if (!file.close()) error("close failed");
    if (i > 0 && i%25 == 0) Serial.println();
    Serial.write('.');
  }
  Serial.println();
  Serial.println("Done");
}
void loop(void){}