You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: readSEL.m
    path of file: ./repos/gptoolbox/mesh
    
    the code of the file until where you have to start completion: function [S] = readSEL(filename)
  % READSEL read selection from .sel file (as used by Mario Botsch and Olga
  % Sorkine in the accompanying data to their survey "On linear variational
  % surface deformation methods" 
  % http://igl.ethz.ch/projects/deformation-survey/
  %

    
function [S] = readSEL(filename)
  % READSEL read selection from .sel file (as used by Mario Botsch and Olga
  % Sorkine in the accompanying data to their survey "On linear variational
  % surface deformation methods" 
  % http://igl.ethz.ch/projects/deformation-survey/
  %
  % Input:
  %   filename  path to .sel file
  % Output:
  %   S #V list of ids:
  %     0  fixed boundary (silver, completely fixed handle-region)
  %     1  interior (blue, "solved-for", "free" region)
  %     2  handle boundary (gold, re-arrangable handle-region)
  % 
  % Example:
  %  S = readSEL(filename);
  %  % Swap 0 (fixed boundary) with 1 (interior) so that selection mask
  %  % functions as handle ids (with 0 meaning interior)
  %  R = (S<1).*1 + (S==1).*0 + (S>1).*S;
  % 

  fp = fopen(filename,'r');
  % read initial comments
  C = textscan(fp, '#%[^\n]');
  % remaining lines contain one integer per line
  S = fscanf(fp,'%d');
  % clean up file
  fclose(fp);
end