teensy-sdfat/SdFat/examples/getline/getline.ino

/*
 * Example of getline from section 27.7.1.3 of the C++ standard
 * Demonstrates the behavior of getline for various exceptions.
 * See http://www.cplusplus.com/reference/iostream/istream/getline/
 *
 * Note: This example is meant to demonstrate subtleties the standard and
 * may not the best way to read a file.
 */
#include <SPI.h> 
#include <SdFat.h>

// SD chip select pin
const uint8_t chipSelect = SS;

// file system object
SdFat sd;

// create a serial stream
ArduinoOutStream cout(Serial);
//------------------------------------------------------------------------------
void makeTestFile() {
  ofstream sdout("GETLINE.TXT");
  // use flash for text to save RAM
  sdout << pstr(
    "short line\n"
    "\n"
    "17 character line\n"
    "too long for buffer\n"
    "line with no nl");

  sdout.close();
}
//------------------------------------------------------------------------------
void testGetline() {
  const int line_buffer_size = 18;
  char buffer[line_buffer_size];
  ifstream sdin("GETLINE.TXT");
  int line_number = 0;

  while (sdin.getline(buffer, line_buffer_size, '\n') || sdin.gcount()) {
    int count = sdin.gcount();
    if (sdin.fail()) {
      cout << "Partial long line";
      sdin.clear(sdin.rdstate() & ~ios_base::failbit);
    } else if (sdin.eof()) {
      cout << "Partial final line";  // sdin.fail() is false
    } else {
      count--;  // Don’t include newline in count
      cout << "Line " << ++line_number;
    }
    cout << " (" << count << " chars): " << buffer << endl;
  }
}
//------------------------------------------------------------------------------
void setup(void) {
  Serial.begin(9600);
  while (!Serial) {}  // wait for Leonardo

  // pstr stores strings in flash to save RAM
  cout << pstr("Type any character to start\n");
  while (Serial.read() <= 0) {}
  delay(400);  // 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(chipSelect, SPI_HALF_SPEED)) sd.initErrorHalt();

  // make the test file
  makeTestFile();

  // run the example
  testGetline();
  cout << "\nDone!\n";
}
//------------------------------------------------------------------------------
void loop(void) {}