title: Wrong bash script syntax
body: <p>I have a script part where I am checking <strong>if</strong> the file exist . I dont find where is my mistake because it jumps to else( file exists) and starts downloading that file. Part of code:</p>
  
  <pre><code>...
      if [ -f '$ins.img' ];
      then
          echo '$ins.img already exists'
      else
         wget http://$2/$ins/$ins.img
      fi
  ...
  </code></pre>