Creating a diary that is not appended to an existing one.

According to Matlab documentation when turning on the diary it appends the commands to the existing diary of the same name. Is there a way not to append, that is to start the diary file afresh? Thanks Tomy

Answer 1

[Dave]

To have the diary name with the date and time when starting use this command:

 diary(['gd_diary_',datestr(now,'dd-mm-yy','local'),'_',datestr(now,'hh-MM-ss','local'),'.txt'])

Answer 2

[Walter Roberson]

http://www.mathworks.com/matlabcentral/newsreader/view_thread/17210

[Tomy Duby]

Well, I tried the delete command. But for some reason it does not work for me: I get the following error message:

Warning: File not found or permission denied

Tomy

[Walter Roberson]

You can use dir() to check the file location. You can use fileattrib to check the permissions.

[Xiaodi]

I guess, before you delete mydiary.out file, you must

 diary off

to close the diary process and then maybe you can delete this mydiary.out file, which is created by

 diary('mydiary.out')

Answer 3

[WAT]

 if (exist(filename))
  delete(filename);
 end

[Jan]

Be careful with the exist command. It accepts existing variables, Java classes and so on. Better:

if exist(FileName, 'file')

But even this accepts folders with this name.

[WAT]

so I guess

 if (exist(Filename, 'file') == 2))

to be even safer then?

[Tomy Duby]

Jan and Walter,

Thanks for your comments. I investigated further the behaviour of Matlab. Here is a sample code that I prepared

%DIARY_DELETE_TEST 
%
% History:
%   Created TD, 2-oct-15
%
% ---------------------------------------------------------------------

      fprintf( 'Turning on the diary\n' )
      diary ( 'test_diary.txt' )
      fprintf( 'The time now is %s\n', datestr( now ) )

      fprintf( 'Turning off the diary\n' )
      diary off

      fprintf( 'Deleting the diary\n' )
      delete( 'test_diary.txt' )
      dir
  end

It works fine, the test_diary.txt file is deleted at the end of this run.

However in my application I create a GUI, use it to manipulate some data and in this environment, even if I close all GUI related stuff, the diary file cannot be deleted from within the calling function.

I did not investigate further as I found a workaround.

Tomy

[Walter Roberson]

I would speculate that at the time you delete() that the current directory is no longer the same directory you created the diary in. Remember that it is always safer to fully-qualify file names.