// Demo of fgets function to read lines from a file. #include #include "SdFat.h" #include "sdios.h" // SD chip select pin const uint8_t chipSelect = SS; SdFat sd; // print stream ArduinoOutStream cout(Serial); //------------------------------------------------------------------------------ // store error strings in flash memory #define error(s) sd.errorHalt(F(s)) //------------------------------------------------------------------------------ void demoFgets() { char line[25]; int n; // open test file SdFile rdfile("fgets.txt", O_RDONLY); // check for open error if (!rdfile.isOpen()) { error("demoFgets"); } cout << endl << F( "Lines with '>' end with a '\\n' character\n" "Lines with '#' do not end with a '\\n' character\n" "\n"); // read lines from the file while ((n = rdfile.fgets(line, sizeof(line))) > 0) { if (line[n - 1] == '\n') { cout << '>' << line; } else { cout << '#' << line << endl; } } } //------------------------------------------------------------------------------ void makeTestFile() { // create or open test file SdFile wrfile("fgets.txt", O_WRONLY | O_CREAT | O_TRUNC); // check for open error if (!wrfile.isOpen()) { error("MakeTestFile"); } // write test file wrfile.print(F( "Line with CRLF\r\n" "Line with only LF\n" "Long line that will require an extra read\n" "\n" // empty line "Line at EOF without NL" )); wrfile.close(); } //------------------------------------------------------------------------------ void setup(void) { Serial.begin(9600); // Wait for USB Serial while (!Serial) { yield(); } cout << F("Type any character to start\n"); while (!Serial.available()) { yield(); } delay(400); // catch Due reset problem // Initialize at the highest speed supported by the board that is // not over 50 MHz. Try a lower speed if SPI errors occur. if (!sd.begin(chipSelect, SD_SCK_MHZ(50))) { sd.initErrorHalt(); } makeTestFile(); demoFgets(); cout << F("\nDone\n"); } void loop(void) {}