How to check if file name has a certain ending?

In the current folder are some files, which do or don't have a filename extension. I would like to check, whether they already have the filename extension or not and add the extension, if necessary.

How do I check the filename extension?

[Azzi Abdelmalek]

Do you mean a specific extension?

[Aaron]

No, in general, although the extension in my case would be ".mat".

Answer 1

[Image Analyst]

Try this:

myFolder = 'C:\whatever';
if ~isdir(myFolder)
  errorMessage = sprintf('Error: The following folder does not exist:\n%s', myFolder);
  uiwait(warndlg(errorMessage));
  return;
end
% Look for all files and add extension of .m if they are missing extension.
filePattern = fullfile(myFolder, '*.*');
allFiles = dir(filePattern);
for k = 1 : length(allFiles)
  baseFileName = allFiles(k).name;
  oldFullFileName = fullfile(myFolder, baseFileName);
  fprintf(1, 'Now reading %s\n', oldFullFileName);
  [folder, baseFileName, extension] = fileparts(baseFileName);
  if isempty(extension)
    % No extension, so add a .m extension
    newBaseFileName = sprintf('%s.m', baseFileName);
    newFullFileName = fullfile(myFolder, newBaseFileName);
    movefile(oldFullFileName, newFullFileName);
    fprintf(1, 'Renamed %s to %s\n', oldFullFileName, newFullFileName);
  end
end

[Aaron]

Thanks!

[Stelios Fanourakis]

Very helpful answer. Thanks a lot!

Answer 2

[dpb]

dNoExt=dir('*.');

Returns all files with no extension in CWD in the dir structure dNoExt. Process as

for i=1:length(dNoExt)
  if dNoExt(i).isdir, continue, end  % skip directory entries
  movefile(dNoExt(i).name,[dNoExt(i).name '.yourextension']);
end

Or, one can cleanup the returned directory entries first before the loop as

dNoExt=dNoExt(~[dNoExt.isdir]);  % retain only files in structure

[Azzi Abdelmalek]

it also returns subfolders

[dpb]

Yeah, that's correct w/ Matlab...I use JPSoft shell with aliases(*) to avoid that so tend to forget. Simple enough to take care of, however, ...

for i=1:length(dNoExt)
  if dNoExt(i).isdir, continue, end  % skip directory entries
  movefile(dNoExt(i).name,[dNoExt(i).name '.yourextension']);
end

(*) The JPSoft command interpreters allow one to write aliases for builtin commands or other programs similarly to aliasing builtin Matlab functions.

C:\> alias dir
*dir /2hzlp /a:-d

C:\> alias ddir
*dir /a:d /hpw

So, if want directories, I use 'ddir', otherwise I'm never bothered by them cluttering up the file list returned. I've often wished TMW had implemented the additional features with dir, especially the attributes. Directories are ok, but the others aren't returned in the structure and altho not often needed, when are it's not particularly convenient. But, as above, having the facility and becoming accustomed to it for so long I occasionally forget not every application "does it right!" :)

[Aaron]

Thanks!

[dpb]

Note the simplification of eliminating the directory entries above if still interested...

Answer 3

[Azzi Abdelmalek]

d=dir('*.*')
e={d.name}'
f=e(~cellfun(@isdir,e))
ii=regexp(f,'\.+','match')
jj=find(cellfun(@isempty ,ii))
g1=f(jj)
g2=strcat(g1,'.ext')
cellfun(@(x,y) movefile(x,y),g1,g2)

[Aaron]

I didn't try your code, because the other answers here seem a bit easier to me. But thank you for your answer!