how to update filename in a call to an external application ?

I just learned how to run a file with an external application. And that works. The application converts a datafile to CSV. The command looks like this:

!C:\Users\hjj019\Desktop\DLConverter.exe C:\Users\hjj019\Desktop\CA\TMWMU645.228

My next challenge, is to change the datafile file name so the routine converts one file after another. I worked out the code below, to find the path of the next file in my folder, but the command does not accept it as a valid file name. First I tried to use datastore, but since my datafiles have all sorts of random file extensions, I gave up on that, and tried a different way.

Here is what I have:

% Specify data location
dataloc = 'C:\Users\hjj019\Desktop\';
location1 = fullfile(dataloc,'CA');
[M,N] = size(dir(location1)) % Number of datalog files
for i = 1:M
  files=dir(location1);
  files1=files(M,1)
  files2=files1.name
  files3 = fullfile(location1,files2)
  % Convert datalog files to CSV
  _italic_
  !C:\Users\hjj019\Desktop\DLConverter.exe files3
end

COMMAND WINDOW:

files1 = struct with fields:

       name: 'TMWMU645.228'
     folder: 'C:\Users\hjj019\Desktop\CA'
       date: '13-jan-2015 09:36:14'
      bytes: 25584
      isdir: 0
    datenum: 7.3598e+05

files2 = 'TMWMU645.228'

files3 = 'C:\Users\hjj019\Desktop\CA\TMWMU645.228'

Error: Could not open file files3

So my question is: How can I insert an updating filename in my file conversion command ?

[Stephen23]

@Hans Jørgen Jensen: it appears that you added markup to your code: was this intended to be for how the code displays on this forum? If so, you might like to read these:

https://www.mathworks.com/matlabcentral/answers/help/markup

https://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup?

[Stephen23]

@Hans Jørgen Jensen: it makes no sense to call dir inside the for loop: you only need to call dir once and loop over the structure that it returns. You will find very clear examples in the MATLAB help:

https://www.mathworks.com/help/matlab/import_export/process-a-sequence-of-files.html

or on this forum:

https://de.mathworks.com/matlabcentral/answers/57446-faq-how-can-i-process-a-sequence-of-files

and I would highly recommend that you follow those examples.

[Hans Jørgen Jensen]

Hi Stephen, thanks for your comments and links. I am not a programmer, so I need all the help I can get. Regarding use of the "!" command to open a file with a windows program: Do you know why it cannot open the file ? (Error: Could not open file files3)

If I type in this way:

!DLConverter.exe TMWMU645.228, it works fine, but if I find the name of the datafile (files3) via the control loop above and use the command like this:

!DLConverter.exe files3

I get this: Error: Could not open file files3

I notice that files3 is in single quotation marks, like this: 'datafile001.456'. Could that be the problem ?

I appreciate any help I can get. I have looked a lot on the community, but not found an answer. Thanks.

Answer 1

[KL]

Hi Hans Jørgen Jensen ,

I've tried your code and yeah, I see your problem. I don't understand it but probably you could simply use system command to accomplish your task. Something like this,

% Specify data location
dataloc = 'C:\Users\hjj019\Desktop';
location1 = fullfile(dataloc,'CA');
[M,N] = size(dir(location1)) % Number of datalog files
files=dir(location1);
for iFile = 3:M
  fileDetails=files(iFile,1)
  fileName = fullfile(location1,fileDetails.name)
  % Convert datalog files to CSV
  system(['C:\Users\hjj019\Desktop\DLConverter.exe ' fileName])
end

[Hans Jørgen Jensen]

Thanks KL, I just got the same answer from someone else this morning, and it works :-)

FileName = files3;

% Convert datalog files to CSV

ConverterCmd = ['"C:\Users\hjj019\Desktop\CA\DLConverter.exe" "' FileName '"'];

[status,cmdout] = system(ConverterCmd,'-echo');