How can I read data from the middle of text file?

If I want to read the data in the following txt file, from S(but not include) to the last 056 and store it into an array, what shall I do?

【FROM 192.168.7.2:658161】 058 032 055 003 056 S 058 032 055 003 056 058 032 055 003 056 058 032 055 003 056 058 032 055 003 056 058 032 055 003 056 058 032 055 003 056 058 032 055 003 056 【FROM 192.168.7.2:658161】

I have tried fscanf(Fid,'%d'). It seems that an empty array is returned, because there are characters in the file.

I have also tried the following one, but it does not work as well. Thank you for giving me a help!

while(1)
 YY=fopen('exp.txt');

   flag=fscanf(YY,'%s');
   if ~isempty(findstr(flag, 'S')),

     data=fscanf(YY,'%d');
     data=data';
     j=size(data);
     data_index=[1:j(2)];
     figure(1);
     plot(data_index,data);

     fclose(YY);

   end
end

[Muthu Annamalai]

See other questions on same topic, http://www.mathworks.com/matlabcentral/answers/?term=textread

and the documentation for textread is your friend http://www.mathworks.com/help/matlab/ref/textread.html

[Walter Roberson]

Odd. What is the unicode code point of that '【' character ?

Answer 1

[per isakson]

Study this:

    function num = cssm()
        str = fileread( 'cssm.txt' );
        ixs = strfind( str, 'S'   );
        ixl = strfind( str, '056' );
        ixs = ixs(1);
        ixl = ixl(end);
        str = str( ixs+1 : ixl+3 );
        num = sscanf( str, '%d' );
    end

where cssm.txt contains (copy&paste) your "file".

[YUMENG]

Thank you very much! It's a nice code and it works very well!

Answer 2

[Cedric]

If your file had multiple lines like

[FROM 192.168.7.2:658161] 058 032 055 003 056 S 070 ... 056
[FROM 192.168.7.2:658161] 058 032 055 003 056 S 071 ... 056
[FROM 192.168.7.2:658161] 058 032 055 003 056 S 072 ... 056
[FROM 192.168.7.2:658161] 058 032 055 003 056 S 073 ... 056

and you wanted to generate a n_lines x n_data array of these values between S no included and last 056 entries included, for each line, you could go for something like:

 buffer = fileread('exp.txt') ;
 D = cell2mat(cellfun(@(m) sscanf(m, '%d'), ...
                      regexp(buffer, '(?<=S\s).*?(?=($|[\r\n]))', 'match'), ...
                      'UniformOutput', false)).' ;

Note that you would be able to build a single array of data only if S was always delimiting the same amount of data within a given file.

Cheers, Cedric

[YUMENG]

Thank you!