title: Link crawler (for download or development)
body: <p>I have a question regarding webcrawling.. 
  What I need is a webcrawler that can save all external links from a website and print them to a file (csv). 
  I am in the middle of developing it myself (with php), but was wondering if there were some downloadable solutions already (doesn't have to be php solution)..
  Of course I have looked for myself, but couldn't find anything. So if anyone can help me out here, I would really appreciate it.</p>
  
  <p>Also, what would be the best way to developing it be? </p>