title: capture first n characters of every line
body: <p>I'm having troubles capturing the  first 6 characters of every line. Supposing I have the following lines inside text.txt:</p>
  
  <pre><code>this is a sentence
  1234567890
  string
  </code></pre>
  
  <p>I would like to get the first 10 chars:</p>
  
  <pre><code>this i
  123456
  string
  </code></pre>
  
  <p>I've tried running <code>grep -Eo "^[a-zA-Z0-9]*{6}" text.txt</code></p>
  
  <p>But grep recycles the regex at every 6th position instead of starting at the next new line. it ends up returning:</p>
  
  <pre><code>this i
  s a se
  ntence
  123456
  7890..
  </code></pre>
  
  <p>what am I doing wrong here?</p>