Wierd Issue observed when reading files with filenames of 13 with same name as a subfolder in the volume working directory. about sdfat

[greiman]

I am not sure what this means:

Only occurs when a sub-folder of the same name as the the bitmap I'm trying to access exist together within the same working directory.

You can't have a sub-folder and file with the same name in a folder.

If you try to do this with Windows 10, it is not allowed an you get the error message:

There is already a folder with the same name as the file name you specified. Specify a different name.

[paqwa]

Hi Bill, thanks for your response. Sorry for not being clearer when describing the issue. Of course you cannot have two files/folders with exactly the same name in the same folder. What I meant was the file and folder have the same name when you exclude the file extension. With the extension included the filename is different to the folder. As an example the folder could be called:

abcdefghijklmno

and the file called

abcdefghijklmno.bmp

I hope this makes sense?

[greiman]

Try this test program. When I run it, it prints this:

Type any character
         0 abcdefghijklmno/
       156 abcdefghijklmno.bmp
Done

#include <SPI.h>
#include "SdFat.h"

#define FOLDER_NAME "abcdefghijklmno"
#define FILE_NAME "abcdefghijklmno.bmp"

//SdFatSdio SD;
SdFatSdioEX SD;

File file;

void setup() {
  Serial.begin(9600);
  while (!Serial) {}
  Serial.println("Type any character");
  while (!Serial.available());
  if (!SD.begin()) {
    Serial.println("begin failed");
    return;
  }
  if (!SD.exists(FOLDER_NAME)) {
    if (!SD.mkdir(FOLDER_NAME)) {
      Serial.println("mkdir failed");
      return;
    }
  }
  if (!SD.exists(FILE_NAME)) {
    if (!file.open(FILE_NAME, O_WRITE | O_CREAT | O_TRUNC)) {
      Serial.println("open write failed");
      return;
    }
    for (int i = 100; i < 256; i++) {
      file.write(i);
    }
    file.close();
  }
  if (!file.open(FILE_NAME, O_READ)) {
    Serial.println("open read failed");
    return;
  }
  for (int i = 100; i < 256; i++) {
    if (file.read() != i) {
      Serial.println("compare failed");
      return;
    }
  }
  SD.ls(LS_SIZE);
  Serial.println("Done");
}
void loop() {}

[paqwa]

Hi Bill, yes this works for me also and thanks for putting it together. It prompted me to re-analyse my code in greater depth. I wrote my code to do different things with the images depending on whether a folder of the same name existed or not and in that section of the code I made a two very rookie mistakes! I didn't allocate a long enough char array for those filenames and upon analyzing my images on the SD card I found that additional information was saved to the file header which was not being skipped over by my code, hence the read error on images.

[paqwa]

So it turns out my issue was just with my novice coding abilities and not with your excellent library, thanks all the same for your responses and guidance on the matter. I will close this issue now.

All the best,
Pat