Saving file with file name from user

I have code for push button where user will click on save, then a folder browser opens where user selects the folder to save the file.

Now here my code:

   filename=('output.xls');
   foldername = uigetdir;

   % ensure the folder name is valid
   if ischar(foldername)
        % update the file name to include the folder name
        filename = fullfile(foldername,filename);
        % open the file
        fid = fopen(filename,'w');
        if fid>0
            % write the data to file
            fprintf(fid, '%6s\t%6s\t\n', 'x', 'y');
            fprintf(fid, '%6.4f\t%6.41f\t\n', result);

            fclose(fid);
        end
   end

So here by default the output file name will be output.xls

I want to have the user capability to set the name of the file. So how to do that?

Answer 1

[Image Analyst]

Let the user type it in with uiputfile(). Here is my snippet for that:

% Get the name of the file that the user wants to save.
% Note, if you're saving an image you can use imsave() instead of uiputfile().
startingFolder = userpath
defaultFileName = fullfile(startingFolder, '*.*');
[baseFileName, folder] = uiputfile(defaultFileName, 'Specify a file');
if baseFileName == 0
  % User clicked the Cancel button.
  return;
end
fullFileName = fullfile(folder, baseFileName)

[adi kul]

Hi, thanks for the answer but where to put the values I want save? Like in my code

% write the data to file
            fprintf(fid, '%6s\t%6s\t\n', 'x', 'y');
            fprintf(fid, '%6.4f\t%6.41f\t\n', result);
            fclose(fid);

writes data, so like in your code, where to put that part?

[Image Analyst]

Right after it.

% Get the name of the file that the user wants to save.
% Note, if you're saving an image you can use imsave() instead of uiputfile().
startingFolder = userpath
defaultFileName = fullfile(startingFolder, '*.*');
[baseFileName, folder] = uiputfile(defaultFileName, 'Specify a file');
if baseFileName == 0
  % User clicked the Cancel button.
  return;
end
fullFileName = fullfile(folder, baseFileName)

fid = fopen(fullFileName, 'wt');
if fid ~= -1
    % write the data to file
    fprintf(fid, '%6s\t%6s\t\n', 'x', 'y');
    fprintf(fid, '%6.4f\t%6.41f\t\n', result);
    fclose(fid);
else
    warningMessage = sprintf('Cannot open file:\n', fullFileName);
    uiwait(warndlg(warningMessage));
end

[adi kul]

Awesome! That worked!

[adi kul]

If I want to save .xls file then what will be the changes?

[Nova Trimble]

May I ask why this won't work for an excel file format as well? I attempted it and it keeps returning the excel file in the folder that the matlab program is being executed.

[Image Analyst]

It does work for any file. It doesn't return an Excel file, it returns a string with the filename that you can then use when you call writetable(), writecell(), xlswrite() or whatever. If the resulting output file is in your current folder, then you're either specifying the current folder, or else you're using only the base file name, not the FULL file name which includes the folder. Show your lines of code if you want me to fix them.

[Adi Purwandana]

Hello, your solution's really great...

Anyway, I tried this on my lines:

ISW = array2table(....); % my output variables

startingFolder = 'D:\';

defaultFileName = fullfile(startingFolder, '*.*');

[baseFileName, folder] = uiputfile(defaultFileName, 'Specify a file');

if baseFileName == 0

% User clicked the Cancel button.

return;

end

writetable(ISW,fullfile(folder,baseFileName)); % but this give me *txt file format, what if I want in xlsx format?

Any solution?

[Adi Purwandana]

I found the solution already... just type '*.xls' to replace '*.*' thank you.

[Image Analyst]

@Adi Purwandana These days we use .xlsx rather than .xls to ensure you get the modern format of the workbook.

Answer 2

[Stephen23]

It depends on how you want them to enter the filename:

• in a GUI, then try uiputfile
• as a variable, then add that variable to the function's input arguments.
• via the command line, then use input to request user input.
• within a custom UI, then use uicontrol 'edit' box.

[adi kul]

Hi, can you give me in the form of code?

I have made these changes

   [fileName,PathName] = uiputfile('*.xls','Save Results As');

   % update the file name to include the folder name
        filename = fullfile(filename,PathName);
        % open the file
        fid = fopen(filename,'w');
        if fid>0
            % write the data to file
            fprintf(fid, '%6s\t%6s\t\n', 'x', 'y');
            fprintf(fid, '%6.4f\t%6.41f\t\n', result);

            fclose(fid);
        end

Now I get a windows to save file but after clicking "save" it doesn't save anything!

[Stephen23]

The path and file arguments around the wrong way in the fullfile call, it should be:

filename = fullfile(PathName,filename);

When you have a problem like this it helps to use the debugging tools, as mistakes like this are easy to find when you check the variables during line-by-line code evaluation.

Note also that you specify the file extension as .xls, but you have opened a textfile and are using fprintf to write text data. This does not make any sense, as .xls files are not text files, but binary files.

You need to decide if you want to work with textfiles or excel files, and then either:

• use a file extension that is suitable for textfiles and will not be mistaken for an .xls file.
• save an .xls file using xlswrite.

[adi kul]

Hi, Thank you but still it's not creating any file!