How can I skip some lines in a text file in order to reach a specific one which is in an undefined position?

   while message1 ~= message(1:size(message1,1),1:size(message1,2))
            message1=fgetl(file_read); % move to the next cluster
            i=i+1;
            if message1 == -1
                message = message1;
                flag=0;
            end
   end

Hello everybody, I have this code line and my aim is to move the cursor down my text file unitl reaching the line stored in the variable "message". Previously on the code I had:

frewind(file_read);
for i=1:19;
    message=fgetl(file_read);
end

Which worked fine because I knew the exact number of lines, but now I'm not able to move forward because, iteratively, matlab read always the same line (message1 remains the same).

How can I solve it?

Answer 1

[David Fink]

Use 'fgetl' and 'isequal' to check each line against the specific one.

Consider the following text file 'find.txt', and the desired line is 'THIS TEXT':

not the
text
THIS TEXT
more text

Then the following MATLAB code will move the file cursor to the beginning of the line after 'THIS TEXT'.

>> f = fopen('find.txt');
>> message = '';
>> while ~isequal(message,'THIS TEXT')
>>     message = fgetl(f);
>> end