title: Regex expression to allow only characters used for writing articles
body: <p>I am looking to construct a regex expression that allows charachters that are used for writing articles, such as: </p>
  
  <ul>
  <li>Alphabets: a-zA-Z</li>
  <li>Numbers: 0-9</li>
  <li>Special characters: -.,+*/'´"!#%&amp;/()=?@£$€{[]}_:;</li>
  <li>Spaces: newlines(enter space) and spaces</li>
  </ul>
  
  <p>My inital attempt using php, looked like this:</p>
  
  <pre><code> preg_replace('/[^a-zA-Z,0-9],.;+- /', ,'', $input)
  </code></pre>
  
  <p>But the line above didn't work</p>
  
  <p>Edit: second attempt to escape the characters to avoid messing up the expression:</p>
  
  <pre><code>preg_replace('/[^a-zA-Z,0-9]\-\.\,\+\*\/\'\´\"\!\#\%\&amp;\/\(\)\=\?\@\£\$\€\{\[\]\}\_\:\;/', '', $input)
  </code></pre>