title: Regex to get first number in string with other characters
body: <p>I'm new to regular expressions, and was wondering how I could get only the first number in a string like <code>100 2011-10-20 14:28:55</code>. In this case, I'd want it to return <code>100</code>, but the number could also be shorter or longer. </p>
  
  <p>I was thinking about something like <code>[0-9]+</code>, but it takes every single number separately (100,2001,10,...)</p>
  
  <p>Thank you.</p>