Re: Alt key not recognized as Meta in xterm
Thanks Andy, your explanation was extremely helpful. For the longest time it was unclear whether the Alt key issue was related to LANG/LC_*, readline / .inputrc, xterm, X resources, or something else entirely. ASCII is much simpler :-) At any rate, things are good now. FWIW, on my Linux box running Slackware64 and twm, I changed LANG from the default en_US to to en_US.UTF-8. This caused the same issue as on Cygwin, and the same .Xdefaults entry fixed it. Gary -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://x.cygwin.com/docs/ FAQ: http://x.cygwin.com/docs/faq/
Re: Alt key not recognized as Meta in xterm
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 -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://x.cygwin.com/docs/ FAQ: http://x.cygwin.com/docs/faq/
Re: Alt key not recognized as Meta in xterm
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). Andy -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://x.cygwin.com/docs/ FAQ: http://x.cygwin.com/docs/faq/
Re: Alt key not recognized as Meta in xterm
On Fri, 1 Jan 2010, Andy Koppe wrote: 2010/1/1 Thomas Dickey: On Fri, 1 Jan 2010, Andy Koppe wrote: XTerm*vt100.metaSendsEscape: true Actually that's not a hack, but the correct solution. I think this needs to be part of the default config in /etc/X11/app-defaults/XTerm. However, the reason that it's not is because there's no standard for the meta key assignment. Understood. I didn't mean it should be the default for Xterm in general, but it should be for Cygwin's version, due to UTF-8 being the default charset. Is Cygwin also specifying a meta key? (some people equate meta==alt, though they're not necessarily the same) -- Thomas E. Dickey http://invisible-island.net ftp://invisible-island.net -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://x.cygwin.com/docs/ FAQ: http://x.cygwin.com/docs/faq/
Re: Alt key not recognized as Meta in xterm
2010/1/1 Thomas Dickey: > On Fri, 1 Jan 2010, Andy Koppe wrote: > >>>XTerm*vt100.metaSendsEscape: true >> >> Actually that's not a hack, but the correct solution. I think this >> needs to be part of the default config in /etc/X11/app-defaults/XTerm. > > However, the reason that it's not is because there's no standard for > the meta key assignment. Understood. I didn't mean it should be the default for Xterm in general, but it should be for Cygwin's version, due to UTF-8 being the default charset. Andy -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://x.cygwin.com/docs/ FAQ: http://x.cygwin.com/docs/faq/
Re: Alt key not recognized as Meta in xterm
On Fri, 1 Jan 2010, Andy Koppe wrote: XTerm*vt100.metaSendsEscape: true Actually that's not a hack, but the correct solution. I think this needs to be part of the default config in /etc/X11/app-defaults/XTerm. However, the reason that it's not is because there's no standard for the meta key assignment. -- Thomas E. Dickey http://invisible-island.net ftp://invisible-island.net -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://x.cygwin.com/docs/ FAQ: http://x.cygwin.com/docs/faq/
Re: Alt key not recognized as Meta in xterm
2009/12/30 Gary Carvell: X issues including xterm ones should go to the cygwin-xfree list. I'm sending this to both lists, but please respond on cygwin-xfree only. > With the upgrade to Cygwin 1.7, I found that the Alt key is no longer > recognized as a Meta key in xterm. This means the Alt based command > line editing keys such as Alt-F/B for forward- and backward-word must > be entered with the Esc key instead. I assume this is related to the > internationalization changes in 1.7. > > I liked the old behavior better, but had some trouble changing it > back. So here's my little hack for this in case anyone else finds it > useful. In your home directory, create a file .Xdefaults containing > this line: > > XTerm*vt100.metaSendsEscape: true Actually that's not a hack, but the correct solution. I think this needs to be part of the default config in /etc/X11/app-defaults/XTerm. When that option is not enabled, 'meta' is sent by setting the highest bit of the metafied character, e.g. 'f' (0x66) turns into 0xE6. That's fine if you're using ASCII only, but obviously it'll conflict with any character encodings beyond ASCII, e.g.in ISO-8859-1 and others, 0xE6 is æ (the ae ligature). And in UTF-8, which of course is the Cygwin default now, a 0xE6 byte would be an incomplete sequence. That's why xterm applies the meta bit before doing the UTF-8 encoding, so Alt-f is sent as \xC3\xA6, which is the UTF-8 encoding for U+00E6 (again: æ) . But bash doesn't recognise that as Alt-f. > I'd be glad to hear any background information on the key mapping > change, or better ways to restore the old behavior. If you don't need anything beyond ASCII, you could go back to a singlebyte charset, e.g. by setting 'LANG=en_US.ISO-8859-1'. Otherwise, the escape prefix is the way to go. Andy -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://x.cygwin.com/docs/ FAQ: http://x.cygwin.com/docs/faq/
