function retrieve_data_block(Input_File_Name, Target_Data_Block_Title, Output_File_Name )
% 
% RETRIEVE_DATA_BLOCK saves the data block with the specified title to the
% output file with the specified name.
%
% retrieve_data_block(Input_File_Name, Target_Data_Block_Title, Output_File_Name)
%
% EXAMPLE: retrieve_data_block('test.dat', 'STOP_RESPONSE', 'output.dat')
% 
% WARNING: Data block title must NOT contain a white space. It has to be one word.
%          Sorry for the limitation.
%
% Tatsuki Kashitani 8/19/2001

% Open input file as read only
Input_File_ID = fopen ( Input_File_Name ,'r');

disp( sprintf('Opened inputfile ''%s''.', Input_File_Name) );

% Initialize line counter
Line_ID = 0;

% Find the line containing Data_Block_Title

while 1
    % Read one line into a string
    Line_String = fgetl ( Input_File_ID );
    
    % Increment line couter by 1
    Line_ID = Line_ID + 1;
    
    % Break from the while-loop if the end of file
    if ischar(Line_String) ~= 1
        disp('End of file reached.');
        break
    end
    
    % Try reading data block title from the string
    Data_Block_Title = sscanf(Line_String, ' Block #%*i: %s %*i ');
    
    % If something could be read...
    if isempty(Data_Block_Title) ~= 1
        
        % Chop off ',' at the end
        Data_Block_Title = Data_Block_Title(1:end-1);
        
        % Compare it to the target data block title. If they match...
        if strcmp ( Data_Block_Title, Target_Data_Block_Title ) == 1
            
            disp( sprintf('Matching data block found at line #%i.', Line_ID) );
            
            % Get number of lines in the data block
            Number_Data_Lines = sscanf ( Line_String, ' Block #%*i: %*s %i ');
            
            disp( sprintf('%i lines are in the data block.', Number_Data_Lines) );
            
            % Skip a blank line
            Line_String = fgetl ( Input_File_ID );
            
            % Create output file
            Output_File_ID = fopen ( Output_File_Name, 'w');

            for Data_Line_ID = 1:Number_Data_Lines
                
                % Read a line into string
                Line_String = fgetl ( Input_File_ID );
                
                % Write the line to the output file
                fprintf(Output_File_ID, '%s\n', Line_String);
                
            end   
            
            % Close output file
            fclose (Output_File_ID);
            
            disp( sprintf('Wrote the data block to output file, ''%s''.', Output_File_Name) );
            
            % Since matching data block is found, break from the while-loop
            break
            
        end
        
    end
    
end


% Close input file    
fclose (Input_File_ID);