75 lines
2 KiB
C++
75 lines
2 KiB
C++
// Demo of fgets function to read lines from a file.
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#include <SdFat.h>
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// SD chip select pin
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const uint8_t chipSelect = SS;
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SdFat sd;
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// print stream
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ArduinoOutStream cout(Serial);
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//------------------------------------------------------------------------------
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// store error strings in flash memory
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#define error(s) sd.errorHalt_P(PSTR(s))
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//------------------------------------------------------------------------------
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void demoFgets() {
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char line[25];
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int n;
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// open test file
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SdFile rdfile("FGETS.TXT", O_READ);
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// check for open error
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if (!rdfile.isOpen()) error("demoFgets");
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cout << endl << pstr(
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"Lines with '>' end with a '\\n' character\n"
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"Lines with '#' do not end with a '\\n' character\n"
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"\n");
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// read lines from the file
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while ((n = rdfile.fgets(line, sizeof(line))) > 0) {
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if (line[n - 1] == '\n') {
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cout << '>' << line;
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} else {
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cout << '#' << line << endl;
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}
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}
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}
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//------------------------------------------------------------------------------
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void makeTestFile() {
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// create or open test file
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SdFile wrfile("FGETS.TXT", O_WRITE | O_CREAT | O_TRUNC);
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// check for open error
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if (!wrfile.isOpen()) error("MakeTestFile");
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// write test file
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wrfile.write_P(PSTR(
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"Line with CRLF\r\n"
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"Line with only LF\n"
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"Long line that will require an extra read\n"
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"\n" // empty line
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"Line at EOF without NL"
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));
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wrfile.close();
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}
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//------------------------------------------------------------------------------
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void setup(void) {
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Serial.begin(9600);
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while (!Serial) {} // Wait for Leonardo
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cout << pstr("Type any character to start\n");
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while (Serial.read() <= 0) {}
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delay(400); // catch Due reset problem
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// initialize the SD card at SPI_HALF_SPEED to avoid bus errors with
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// breadboards. use SPI_FULL_SPEED for better performance.
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if (!sd.begin(chipSelect, SPI_HALF_SPEED)) sd.initErrorHalt();
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makeTestFile();
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demoFgets();
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cout << pstr("\nDone\n");
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}
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void loop(void) {}
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