Count numer of lines in a MATLAB script, ignoring comments and blanks

Is there a way to count the number of lines in a MATLAB script or function, but not count blank and comment lines?

[Walter Roberson]

There is no supplied way to do this.

If you do this yourself you need to watch out for %{ %} multi line comments

Fortunately matlab does not permit literals to be split between lines so you do not need to worry about ... sequences potentially hiding the fact that a line starting with a % might hypothetically be part of a string rather than a comment.

Answer 1

[Adam Danz]

Try this out. After reading the entire file, separated by line, it removes any leading white space, then gets rid of empty lines, then gets rid of lines that start with %. Finally, it counts the number of lines left over. View "fileStr" to see what's being counted.

file = 'myfile.m';                                          % name file to read
fileChar = fileread(file);                                  % read file (char)
fileStr = strtrim(regexp(fileChar, '\n', 'split'))';        % split lines, remove leading while space
% Remove empty lines
fileStr(cellfun(@isempty, fileStr)) = []; 
% Detect contiguous comments
startIdx = cumsum(cellfun(@(x)strcmp(x,'%{'), fileStr)); 
stopIdx = cumsum(cellfun(@(x)strcmp(x,'%}'), fileStr) & startIdx>0);
contigIdx = (startIdx - stopIdx) > 0; 
fileStr(contigIdx) = []; 
% Remove lines that are comments
fileStr(cellfun(@(x)strcmp(x(1),'%'), fileStr)) = []; 
% Count number of lines left
nLines = length(fileStr); 

I tested it on a number of files and looks OK.

Updated: 4 lines in the middle added to deal with contigious comments (good catch, Walter).

[Walter Roberson]

%{ comments?

[Adam Danz]

Ah.... I've never used those and therefore overlook that possibility. I'll have to edit my answer.

[Adam Danz]

@ Jeffrey Snively, make sure you get the most up to date version. I tried to break it lots of ways to iron out the kinks. If I make any more changes going forward I'll add a comment here to explain what they were.