Is it possible to programmatically add a file extension for syntax highlighting?

Hi,

Is it possible to programmatically add a file extension for syntax highlighting?

Just for the sake of argument, suppose I have a file with extension "xtn". It is possible to go into

preference-->editor/Debugger-->language

and from there add extension xtn under the block "file extensions". Then matlab will apply the same syntax coloring it uses for files with extension .m to all files with extension xtn.

Is there any way to do this programmatically instead of manually?

Thanks

Answer 1

[Jan]

You can do it the hard way:

Open the file prefdir\matlab.prf. Search for the variable "Editor.Language.MATLAB.Extensions" and append 'xtn'.

Ext = 'xtn';
PrefFile = fullfile(prefdir, 'matlab.prf');
copyfile(PrefFile, [PrefFile, '.bak']);  % To be secure
fid = fopen(PrefFile, 'r');
if fid == -1
  error('Cannot open file for reading: %s', PrefFile);
end
C = textscan(fid, '%s', 'Delimiter', '\n');
Data = C{1};
fclose(fid);

key     = 'Editor.Language.MATLAB.Extensions';
index   = strncmp(Data, key, length(key));
if sum(index) ~= 1
  error('Cannot identify key line.');
end
keyLine  = Data{index};
keyData  = keyLine(length(key) + 3:end);  % <key>=S...
keyValue = regexp(keyData, ';', 'split');
if ~any(strcmpi(keyValue, Ext))
  keyData = [keyData, ';', Ext];
end
Data{index} = [key, '=S', keyData];

% Save the file:
fid = fopen(PrefFile, 'w');
if fid == -1
  error('Cannot open file for writing: %s', PrefFile);
end
fprintf(fid, '%s\n', Data{:});
fclose(fid);

Afterwards restart Matlab:

!matlab
quit

Or you use the smart, but undocumented methods:

key      = 'Editor.Language.MATLAB.Extensions';
keyData  = com.mathworks.services.Prefs.getPref(key);
keyValue = regexp(keyData, ';', 'split');
if ~any(strcmpi(keyValue, Ext))
  keyData = [keyData, ';', Ext];
  com.mathworks.services.Prefs.setStringPref(key, keyData);
end

This worked 2007 (see http://mathworks.com/matlabcentral/newsreader/view_thread/154608) and in R2011b. But as all undocumented methods this might change in the future.

Finally, let me mention, that this does not look like a useful method to me. I guess that it is easier to change the file extension from the concerned files.

[Patrick Mboma]

Dear Jan,

Thanks for the answer. What I am hoping for is something simple that I can turn on and off straight from the command window.

It could be something like

 add_extension('xtn')
 remove_extension('xtn')

Of course if it is too complicated, which would be a pity, I would simply have to revert to the textbook way of doing it.

[Jan]

Too complicated? I've posted 2 solutions already. So simply copy&paste one of them into a function called "add_extension". All you have to modify for "remove_extension" is:

match = strcmpi(keyValue, Ext);
if any(match)
  keyValue(match) = [];
  keyData = sprintf('%s;', keyValue{:});
  keyData(end) = [];
  com.mathworks.services.Prefs.setStringPref(key, keyData);
end