How to add a new line in the middle of a text file?

Hi all,

I have a text file in which I need to add a new line of text using Matlab. I know the number of the line, where the line should be inserted. However, I don't know how to create and fill a new line at this position. Can any of you help me out?

Thanks, Ellen

Answer 1

[per isakson]

There is no "smart" way. One has to read the existing file and write the new. If the file isn't too large this could be a starting point.

    fid = fopen( old_filespec );
    cac = textscan( fid, '%s', 'Delimiter','\n', 'CollectOutput',true );
    fclose( fid )

    fid = fopen( new_filespec, 'w' );

    for jj = 1 : insert_here
        fprintf( fid, '%s\n', cac{jj} );
    end
    fprintf( fid, '%s\n', new_line );
    for jj = insert_here+1 : length(cac)
        fprintf( fid, '%s\n', cac{jj} );
    end
    fclose( fid );