# $EPIC: backward_history,v 1.3 2001/04/25 19:59:00 jnelson Exp $
Synopsis:
   bind <key> backward_history

Description:
   If there are no entries in the command history, nothing happens.

   If this is the first time this keybinding has been used since the
   last time the history position was reset [see below], then the contents 
   of the input line are added to the bottom of the history.

   Unless the history position is at the "top" of the history (pointing at
   the oldest entry), the history position is moved to the next older entry
   in the history.

   But if the history position is at the "top" of the history (pointing at
   the oldest entry), then if /SET HISTORY_CIRCLEQ is ON, the history position
   is moved to the bottom (newest entry) of the history.  

   If the history position is at the "top" of the history and 
   /SET HISTORY_CIRCLEQ is OFF, the history position is not changed.

   The contents of the input line are replaced with the contents of the
   current history position.

See Also:
   bind(4) forward_history, shove_to_history; history(4)

History Line Resets:
   The history position is reset whenever anything is added to the history,
   using the SENDLINE keybinding or the SHOVE_TO_HISTORY keybinding.

   The history position is also reset whenever the ERASE_LINE keybinding is
   used when /SET HISTORY_CIRCLEQ is ON.
