Method FindFirst

src/Storage/MassStorage.cpp:800–844

Open a directory to read a file list. Returns true if it contains any files, false otherwise. If this returns true then the file system mutex is owned. The caller must subsequently release the mutex either by calling FindNext until it returns false, or by calling AbandonFindNext.

// If this returns true then the file system mutex is owned. The caller must subsequently release the mutex either
// by calling FindNext until it returns false, or by calling AbandonFindNext.
bool MassStorage::FindFirst(const char *_ecv_array directory, FileInfo &file_info) noexcept
{
	// Remove any trailing '/' from the directory name, it sometimes (but not always) confuses f_opendir
	String<MaxFilenameLength> loc;
	loc.copy(directory);
	const size_t len = loc.strlen();
	if (len != 0 && (loc[len - 1] == '/' || loc[len - 1] == '\\'))
	{
		loc.Truncate(len - 1);
	}

	if (!dirMutex.Take(10000))
	{
		return false;
	}

#if HAS_MASS_STORAGE
	if (f_opendir(&findDir, loc.c_str()) == FR_OK)
	{
		FILINFO entry;
		for (;;)
		{
			const FRESULT res = f_readdir(&findDir, &entry);
			if (res != FR_OK || entry.fname[0] == 0) break;
			if (!StringEqualsIgnoreCase(entry.fname, ".") && !StringEqualsIgnoreCase(entry.fname, ".."))
			{
				file_info.isDirectory = (entry.fattrib & AM_DIR);
				file_info.fileName.copy(entry.fname);
				file_info.size = entry.fsize;
				file_info.lastModified = ConvertTimeStamp(entry.fdate, entry.ftime);
				return true;
			}
		}
		f_closedir(&findDir);
	}
#elif HAS_EMBEDDED_FILES
	if (EmbeddedFiles::FindFirst(directory, file_info))
	{
		return true;
	}
#endif

	dirMutex.Release();
	return false;
}

// Find the next file in a directory. Returns true if another file has been read.
// If it returns false then it also releases the mutex.