title: Find float in a text file
body: <p>I am trying to find some float number (like -1234.5678) in a huge text file using grep, so I thought about:</p>
  
  <p>grep -n '-1234.5678'</p>
  
  <p>but I get errors, do you know what is the right way using grep and why? there is anything easier?</p>
  
  <p>Thanks</p>