function dataDir = openConfigFile(configFile, logFileID)
%OPENCONFIGFILE open file config.txt and read dataDir
%   Config file must follow specific/restrictive rules
% Author: AT
% Date: 2019-01-15
% TODO: Less restrict rules for writting confix.txt

if ~exist(configFile, 'file')
    error([configFile, ' required']);
end
fileID = fopen(configFile,'r');
dataDir = fscanf(fileID, '%s'); % Read config file without spaces
fclose(fileID);
k = strfind(dataDir, 'dataDir='); % Find definition of dataDir
k = k + 8; % Remove 'dataDir='
dataDir = dataDir(k:end); % Assume that config file ends with dataDir content
% Check if dataDir exists
if ~exist(dataDir, 'dir')
    fprintf(logFileID, ['Data directory not found, check ' configFile]);
    error(['Data directory not found, check ' configFile]);
end

end