converting *char array to string

Projects Programming
1

Hi, there! Please bear with me on this one since I tried to make this as clear as possible.

I'm working on this Arduino project that involves Adafruit Wave Shield and buttons. I simply wanted to build a simple music launchpad / drumkit with them.

So in order to do it, I planned to store the filenames inside a *char array. Why? Because the Wave Shield library only uses *char as its parameter. I could also only get the filename from the "dirBuf" register (dirBuf.name to be exact) in the SD card, which is also *char.

The problem though is that whenever I try to copy the filename directly from the SD card / dirBuf register, the period / dot from the extension file ".WAV" gets deleted but what I need is to store the exact, original filename inside my designated array for future use.

So in order to do that, I need to duplicate it to a string variable so I can replace "WAV" with ".WAV" (notice the period for comparison) since *char values are immutable.

Now, my code (as seen below) works but only for the first 4 files read and I heard String can be problematic so I'm asking for help on how to modify this code into a reliable and consistent one.

Here's a snippet of my code:

char *temp=dirBuf.name; //declare a local *char variable so it's compatible with dirBuf.name

String toString = String(temp); //convert *char into String

toString = toString.substring(0, toString.length()-4); //remove "WAV" from the file name since it's missing a dot

toString.concat(".WAV"); //add ".WAV" to the filename to equalize it with the original filename

char *cstr = &toString[0]; //get updated string and store it in a new array of pointers

Thanks!

2

Fair warning: snippets are frowned upon. You may wish to edit your post to include the entire sketch. Or, if it's too long work up an MCVE. Trust me, it'll save time.

3

Thank you for the heads-up. Will modify and work on an MCVE asap!

4 
  char extension[] = ".WAV";
  char *temp = (char*)malloc(strlen(dirBuf.name) + 1);
  
  memcpy(temp, dirBuf.name, strlen(dirBuf.name));
  memcpy(temp + (strlen(dirBuf.name) - 3), extension, strlen(extension));

  Serial.println(temp);