On Fri, 1 Jan 2010, Andy Koppe wrote:
2010/1/1 Thomas Dickey:
Is Cygwin also specifying a meta key?
(some people equate meta==alt, though they're not necessarily the same)
I don't know whether there's ever been an official policy decision on
that, but I think the general assumption among Cygwin users is that
Alt==Meta, since of course PC keyboards don't have a Meta key yet lots
of programs expect one.
I realise that in X it is possible to map a different key to Meta, but
the altIsNotMeta setting is off by default in Cygwin's xterm. Also,
the Cygwin console, rxvt, and mintty (via PuTTY) assume that Alt is
Meta (and they all encode it as Escape by default).
iirc, Cygwin console (unless something's changed in 1.7) and rxvt don't
actually do the meta function as described in the terminfo manpage, e.g.,
If the terminal has a ``meta key'' which acts as a shift key, setting
the 8th bit of any character transmitted, this fact can be indicated
with km. Otherwise, software will assume that the 8th bit is parity
and it will usually be cleared. If strings exist to turn this ``meta
mode'' on and off, they can be given as smm and rmm.
Rather, they're assuming that meta is a way to put an escape character in
front of other keys. That's reflected in readline's manpage:
An emacs-style notation is used to denote keystrokes. Control keys are
denoted by C-key, e.g., C-n means Control-N. Similarly, meta keys are
denoted by M-key, so M-x means Meta-X. (On keyboards without a meta
key, M-x means ESC x, i.e., press the Escape key then the x key. This
makes ESC the meta prefix. The combination M-C-x means ESC-Control-x,
or press the Escape key then hold the Control key while pressing the x
key.)
however (same manpage)
convert-meta (On)
If set to On, readline will convert characters with the eighth
bit set to an ASCII key sequence by stripping the eighth bit and
prefixing it with an escape character (in effect, using escape
as the meta prefix).
...
input-meta (Off)
If set to On, readline will enable eight-bit input (that is, it
will not clear the eighth bit in the characters it reads),
regardless of what the terminal claims it can support. The name
meta-flag is a synonym for this variable.
--
Thomas E. Dickey
http://invisible-island.net
ftp://invisible-island.net
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