* Re: A different approach to PROMPT_CR [not found] <1000826175034.ZM13455@candle.brasslantern.com> @ 2000-08-26 20:46 ` Zefram 2000-08-26 22:27 ` Bart Schaefer 0 siblings, 1 reply; 3+ messages in thread From: Zefram @ 2000-08-26 20:46 UTC (permalink / raw) To: Bart Schaefer; +Cc: zsh-workers Bart Schaefer wrote: >When promptnl runs, it asks the terminal to send back the current position >of the cursor. If the cursor is in column 1, it does nothing; otherwise it >prints a newline. Thus you get a newline exactly when one is needed. This will eat any typeahead. Actually, if an "R" is typed ahead it'll get confused. (Just pointing this out for discussion below.) >for example use EOLMARK='%B!%b' to put a bold exclamation point at the end >of the actual output. This is neat, and solves one of my basic objections to shells outputting a newline before the prompt (that it hides any missing-final-newline bugs in programs that you run -- it's a bit of a feature of MS-DOS that programs do that). >This could be coded in C and added to ZLE ... `setopt PROMPT_NL', anyone? Hmm. There are two issues with doing it in the C code. One is the matter of putting terminal-specific features into the base shell. This is handleable: with PROMPT_NL set, we'd do this differently depending on TERM. With vt100-compatible terminals we'd do it the way your shell function does, with other terminals we'd use different escape sequences, and with unknown terminals we'd do nothing. The other issue is the typeahead problem noted above. Integrating this into ZLE could mostly solve that. Firstly, we can refuse to attempt anything if we detect typeahead. Then, for terminal types that return the cursor position in a recognisable form, if what we get isn't in the expected form we can abandon the attempt and use what we read as normal input. It'd still sometimes go wrong, particularly over slow links, but of course it's easy to turn off. -zefram ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: A different approach to PROMPT_CR 2000-08-26 20:46 ` A different approach to PROMPT_CR Zefram @ 2000-08-26 22:27 ` Bart Schaefer 2000-08-28 20:47 ` Peter Stephenson 0 siblings, 1 reply; 3+ messages in thread From: Bart Schaefer @ 2000-08-26 22:27 UTC (permalink / raw) To: Zefram; +Cc: zsh-workers On Aug 26, 9:46pm, Zefram wrote: } Subject: Re: A different approach to PROMPT_CR } } This will eat any typeahead. Actually, if an "R" is typed ahead it'll } get confused. Hmm, what will "stty -echo" do to typeahead? Would it suffice to insert if read -t -k 1 then print -z $REPLY return 0 fi before the stty call? It might be nice if "read -t -k 0" simply returned 0 if there's pending input and 1 otherwise, without reading anything. Right now, -k 0 is treated the same as -k 1 (read always reads at least one byte). -- Bart Schaefer Brass Lantern Enterprises http://www.well.com/user/barts http://www.brasslantern.com Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: A different approach to PROMPT_CR 2000-08-26 22:27 ` Bart Schaefer @ 2000-08-28 20:47 ` Peter Stephenson 0 siblings, 0 replies; 3+ messages in thread From: Peter Stephenson @ 2000-08-28 20:47 UTC (permalink / raw) To: Zsh hackers list "Bart Schaefer" wrote: > It might be nice if "read -t -k 0" simply returned 0 if there's pending > input and 1 otherwise, without reading anything. Right now, -k 0 is > treated the same as -k 1 (read always reads at least one byte). Yes, but I had to make it read a character as a last resort since on cygwin checking for pending input didn't work. Somebody will have to find a way of making this work everywhere. While there about it, they could also find a way of making the read time out on all systems, which was the other thing I tried to do. -- Peter Stephenson <pws@pwstephenson.fsnet.co.uk> Work: pws@csr.com Web: http://www.pwstephenson.fsnet.co.uk ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2000-08-28 20:48 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- [not found] <1000826175034.ZM13455@candle.brasslantern.com> 2000-08-26 20:46 ` A different approach to PROMPT_CR Zefram 2000-08-26 22:27 ` Bart Schaefer 2000-08-28 20:47 ` Peter Stephenson
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