✨Add list_files function #615

include/pros/misc.hpp

@@ -549,24 +549,25 @@ Lists the files in a directory specified by the path
  * \note use a path of "\" to list the files in the main directory NOT "/usd/"
  *  DO NOT PREPEND YOUR PATHS WITH "/usd/"
  * 
- * \return 1 on success or PROS_ERR on failure setting errno
+ * \return vector of std::string of file names, if error occurs, returns vector containing
+ * one element, PROS_ERR
  * 
  * \b Example
  * \code
  * void opcontrol() {
  * 	char* test = (char*) malloc(128);
- *	pros::usd::list_files("/", test, 128);
+ *	std::vector<std::string> files = list_files("/", test, 128);
  *	pros::delay(200);
- *	printf("%s\n", test); //Prints the file names in the root directory seperated by newlines
- *  pros::delay(100);
- *  pros::list_files("/test", test, 128);
- *	pros::delay(200);
- *	printf("%s\n", test); //Prints the names of files in the folder named test seperated by newlines
- *  pros::delay(100);
+ *	// Given vector of std::string file names, print each file name
+ *  // Note that if there is an error, the vector will contain one element, PROS_ERR
+ *  // Print each file name
+ *	for (std::string file : files) {
+ *		std::cout << file << std::endl;
+ *	}
  * }
  * \endcode
 */
-std::int32_t list_files(const char* path, char* buffer, std::int32_t len);
+std::vector<std::string> list_files(const char* path, char* buffer, int32_t len);
 }  // namespace usd
 
 }  // namespace pros

src/devices/vdml_usd.cpp

@@ -21,8 +21,39 @@ std::int32_t is_installed(void) {
 	return usd_is_installed();
 }
 
-int32_t list_files(const char* path, char* buffer, int32_t len) {
-	return usd_list_files(path, buffer, len);
+std::vector<std::string> list_files(const char* path, char* buffer, int32_t len) {
+	std::vector<std::string> files = {};
+	// Call the C function
+	int32_t success = usd_list_files(path, buffer, len);
+	// Check if call successful, if PROS_ERR return vector containing PROS_ERR
+	if (success == PROS_ERR) {
+		// push_back PROS_ERR to files vector
+		files.push_back(std::to_string(success));
+		return files;
+	}
+	// Parse buffer given call successful, split by '/n'
+	// Store char * buffer as std::string in str
+	// Store delimiter in std::string, '\n'
+	std::string str(buffer);
+	std::string delimiter = "\n";
+
+	// position to keep track of position in str
+	// file_name used to store each file name
+	size_t position = 0;
+	std::string file_name;
+
+	// Loop until delimiter '\n' can not be found anymore
+	while ((position = str.find(delimiter)) != std::string::npos) {
+		// file_name is the string from the beginning of str to the first '\n', excluding '\n'
+		file_name = str.substr(0, position);
+		// Add token to files vector
+		files.push_back(file_name);
+		// Erase file_name from str, would be pos + 1 if we wanted to include '\n'
+		str.erase(0, position + 1);
+	}
+
+	// return vector of file names
+	return files;
 }
 
 }  // namespace usd