title: How I can use array in exec and imgaemagick
body: <p>I need to run a command line with imagemagick, php, exec().</p>
  
  <p>I have an array like this:</p>
  
  <pre><code>$png[0];
  $png[1];
  $png[2];
  $png[3];
  $png[4];
  ...
  </code></pre>
  
  <p>then i have:</p>
  
  <pre><code>exec("convert ".$png['0']." ".$png['1']." ".$png['2']." -background none -gravity North -append result.jpg");
  </code></pre>
  
  <p>which work very good and create result.jpg by using -append, but i need use array like $png[] or in loop,because my $png[] key in array creates dynamic with a for loop on above of this codes.</p>
  
  <p>any help please?
  (sorry for my bad English)</p>