csv_helpers.h

//csvReadText() and csvReadInt() are from the SdFat example "readCsv.ino"  Copyright (c) 2011-2018 Bill Greiman under MIT license
//All other code is based on the same example

#ifndef CSV_HELPERS_h
#define CSV_HELPERS_h
/*
 * Read a file one field at a time.
 *
 * file - File to read.
 *
 * str - Character array for the field.
 *
 * size - Size of str array.
 *
 * delim - csv delimiter.
 *
 * return - negative value for failure.
 *          delimiter, '\n' or zero(EOF) for success.           
 */
int csvReadText(File* file, char* str, size_t size, char delim) {
  char ch;
  int rtn;
  size_t n = 0;
  while (true) {
    // check for EOF
    if (!file->available()) {
      rtn = 0;
      break;
    }
    if (file->read(&ch, 1) != 1) {
      // read error
      rtn = -1;
      break;
    }
    // Delete CR.
    if (ch == '\r') {
      continue;
    }
    if (ch == delim || ch == '\n') {
      rtn = ch;
      break;
    }
    if ((n + 1) >= size) {
      // string too long
      rtn = -2;
      n--;
      break;
    }
    str[n++] = ch;
  }
  str[n] = '\0';
  return rtn;
}

int csvReadInt(File* file, int* num, char delim) {
  char buf[20];
  char* ptr;
  int rtn = csvReadText(file, buf, sizeof(buf), delim);
  if (rtn < 0) return rtn;
  *num = strtol(buf, &ptr, 10);
  if (buf == ptr) return -3;
  while(isspace(*ptr)) ptr++;
  return *ptr == 0 ? rtn : -4;
}

int csvReadBool(File* file, bool* boolptr, char delim) {
  char buf[20];
  char* ptr;
  int rtn = csvReadText(file, buf, sizeof(buf), delim);
  if (rtn < 0) return rtn;
  *boolptr = strtol(buf, &ptr, 10) == 1 ? true : false;
  if (buf == ptr) return -3;
  while(isspace(*ptr)) ptr++;
  return *ptr == 0 ? rtn : -4;
}

int csvReadPBType(File* file, PlaybackType* type, char delim) {
  char buf[20];
  char* ptr;
  int rtn = csvReadText(file, buf, sizeof(buf), delim);
  if (rtn < 0) return rtn;
  *type = (PlaybackType)strtol(buf, &ptr, 10);
  if (buf == ptr) return -3;
  while(isspace(*ptr)) ptr++;
  return *ptr == 0 ? rtn : -4;
}

int csvReadPBState(File* file, PlaybackState* state, char delim) {
  char buf[20];
  char* ptr;
  int rtn = csvReadText(file, buf, sizeof(buf), delim);
  if (rtn < 0) return rtn;
  *state = (PlaybackState)strtol(buf, &ptr, 10);
  if (buf == ptr) return -3;
  while(isspace(*ptr)) ptr++;
  return *ptr == 0 ? rtn : -4;
}
#endif //CSV_HELPERS_h