title: gdb search command history with partial match
body: <p>When searching gdb command history, is there a way to go through only those command matching a given one?</p>
  
  <p>for example, sometimes I only want to search previous break commands, not the entire command history. Is there a shortcut to only go through commands that start with "break" or "b"? That can save me a million keystroke. </p>