ee (easy editor) bugged on 9.0?

Ed Schouten ed at
Wed Nov 23 18:11:34 UTC 2011

Hi Jason,

* Jason Edwards <sub.mesa at>, 20111122 21:56:
> I wonder: is cons25 bugged or simply obsolete? Not that I want to keep
> cons25; just being curious.

There are two reasons why I changed the default terminal emulator to be
xterm-like, instead of conforming to cons25:

- It is more compatible. Not all operating systems have proper cons25
  entries in their termcap/terminfo, meaning it is practically
  impossible to SSH to one of those systems and do your work properly.
  Also, there are many devices (e.g. Cisco/HP switches) that don't offer
  a lot of flexibility with respect to terminal handling. By using an
  xterm-style emulator, this is all solved, because xterm is pretty much
  compatible with VT100 and friends.

- It is more bandwidth efficient. cons25-like terminals do not (have to)
  support more advanced features like scrolling regions. This means for
  example that if you use applications where only a portion of the
  screen scrolls (e.g. irssi, mutt), it has to redraw that entire
  portion of the screen, instead of being able to simply scroll that
  independent region, without affecting the rest of the display
  contents. This is of course no problem when running applications
  locally, but it does have its advantages when SSHing to another

- It is more future proof. There are many implementations of xterm-like
  terminals that demonstrate that it's not hard to get (a sane subset
  of) UTF-8 and 256 colors working. Things like that are simply not
  available for cons25.

As people pointed out, if you still want to keep on using TERM=cons25
(not advised, though), you _MUST_ either compile your kernel with
TEKEN_CONS25 or run vidcontrol -T cons25. This is due to the fact that
cons25-like terminals are incompatible with xterm-like terminals. For

- With xterm, ^N and ^O are used to switch character maps, while with
  cons25, they render a music note and star symbol.

- With xterm, processing backspace while the cursor is at the first
  column of the screen does nothing, while cons25 performs reverse line

- With xterm, ^L is interpreted as a newline, while with cons25, it
  clears the entire screen.

- With xterm, line wrapping of the cursor on a display of n columns wide
  is only performed when printing the n+1'th character, while cons25
  already does this after the n'th character. Effectively, this makes it
  very hard to print a character in the lower righthand corner of the

One of these incompatibilities is likely what caused the problems you
experienced when you ran ee(1) without updating /etc/ttys accordingly.

 Ed Schouten <ed at>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 834 bytes
Desc: not available
Url :

More information about the freebsd-current mailing list