gph@hpsemc.HP.COM (Paul Houtz) (05/10/89)
I have a question about Unix type-ahead: Do all unix systems echo the characters to the screen no matter what is going on as you type them? I have only worked on one type. The VMS systems I have worked on have type-ahead, and it buffers what you type without echoing until it is ready to actually execute the command. It's been a while since I used it, but I find the VMS implementation to be more logical, in that I don't end up with parts of command repeated at the prompt. On unix, I find myself having to backspace to see which characters DON'T disappear. Is this implementation dependent?
prc@erbe.se (Robert Claeson) (05/11/89)
In article <810053@hpsemc.HP.COM>, gph@hpsemc.HP.COM (Paul Houtz) writes: > Do all unix systems echo the characters to the screen no matter what > is going on as you type them? I have only worked on one type. Yes, unless echo is disabled by you or the command you're currently running. ..... > On unix, I find myself having to backspace to see which characters DON'T > disappear. > > Is this implementation dependent? No, it's normal behaviour. BTW, Korn shell will print out the complete input buffer again when it prints out its prompt. -- Robert Claeson E-mail: rclaeson@erbe.se ERBE DATA AB
barnett@crdgw1.crd.ge.com (Bruce Barnett) (05/11/89)
In article <677@maxim.erbe.se>, prc@erbe (Robert Claeson) writes: >In article <810053@hpsemc.HP.COM>, gph@hpsemc.HP.COM (Paul Houtz) writes: > >> Do all unix systems echo the characters to the screen no matter what >> is going on as you type them? I have only worked on one type. > >Yes, unless echo is disabled by you or the command you're currently running. If the line you are typing is interrupted by the output from some command, you could try Control-R to refresh the line. I must admit that I like seeing the line I am typing in, and can type ahead without worrying about typo's. -- Bruce G. Barnett <barnett@crdgw1.ge.com> a.k.a. <barnett@[192.35.44.4]> uunet!steinmetz!barnett, <barnett@steinmetz.ge.com>
gandalf@csli.Stanford.EDU (Juergen Wagner) (05/12/89)
In article <810053@hpsemc.HP.COM> gph@hpsemc.HP.COM (Paul Houtz) writes: >... > Do all unix systems echo the characters to the screen no matter what >is going on as you type them? I have only worked on one type. >... It depends on whether the driver which accepts character by character from a terminal echoes input (because it is in some `echo' mode), or whether your application has to decide the question of echoing. By default, UNIX shells put the terminal driver into a mode in which it echoes all its input. That's reasonable for most applications. However, under Emacs and other programs which perform special interpretation of characters, and/or wish to maintain a particular screen layout, it is necessary to echo characters from the respective application program. If UNIX could echo characters as they are *consumed* by the program which reads from a terminal, as opposed to when they are *typed*, you would get the desired behavior. -- Juergen Wagner gandalf@csli.stanford.edu wagner@arisia.xerox.com
andy@syma.sussex.ac.uk (Andy Clews) (05/12/89)
From article <810053@hpsemc.HP.COM>, by gph@hpsemc.HP.COM (Paul Houtz): > The VMS systems I have worked on have type-ahead, and it buffers what > you type without echoing until it is ready to actually execute the command. > ..... > On unix, I find myself having to backspace to see which characters DON'T > disappear. You could always do a CTRL R to refresh your command line when the prompt finally appears. Although I'm a confirmed UNIX fan, this is one of the features that I like in the VMS ennvironment. Now don't let's start another UNIX/VMS war :-) I guess it's the tty driver that's to blame, rather than the Shell. -- Andy Clews, Computing Service, Univ. of Sussex, Brighton BN1 9QN, ENGLAND JANET: andy@syma.sussex.ac.uk BITNET: andy%syma.sussex.ac.uk@uk.ac Voice: +44 273 606755 ext.2129
chris@mimsy.UUCP (Chris Torek) (05/13/89)
In article <8942@csli.Stanford.EDU> gandalf@csli.Stanford.EDU (Juergen Wagner) writes: >If UNIX could echo characters as they are *consumed* by the program >which reads from a terminal, as opposed to when they are *typed*, you >would get the desired behavior. This would be easy to implement. The question is `desired by whom'--- certainly not me. Except when it would create real trouble (e.g., in vi, Emacs, rogue/hack/moria, ...) I prefer to see what I am typing-ahead. VMS (and a number of other systems) do have an advantage over traditional Unix tty drivers, however, in the area of fast echo during edit sessions or other `controlled screen' times. Here, the application should be allowed to tell the system which characters should merely echo and be queued, and which should not echo, but rather cause the application to wake up and see what has been typed thus far. This must be accompanied by a maximum input length (to avoid screen wraparound in some cases). The matter gets rather complicated because of the vagaries of various terminals; VMS and many (if not all) of those other systems cheat by assuming that you have a particular brand of terminal attached. But it is possible to do right, and it does improve interactive response in those special cases where it may be used. -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163) Domain: chris@mimsy.umd.edu Path: uunet!mimsy!chris
dhesi@bsu-cs.bsu.edu (Rahul Dhesi) (05/14/89)
It's a question of whether you "Think VMS" or "Think UNIX". If I use
VMS for a while, I get used to typing commands like
cc x <cr>
link x <cr>
run x <cr>
quickly, and the commands are echoed as they are executed one by one.
Then when I move to UNIX, for a while I do the same and I find it
annoying that characters get echoed as I type them. But soon I begin
to "Think UNIX" again, and I instead type
cc x; a.out
or better still:
cc x && a.out
You see, if you "Think UNIX", you use the semicolon to separate
multiple commands rather than newlines, and you learn to use && to
connect commands when suitable. *Then*, when you move back to VMS,
it's annoying that you can't do this any more.
So it's all a question of your state of mind.
--
Rahul Dhesi <dhesi@bsu-cs.bsu.edu>
UUCP: ...!{iuvax,pur-ee}!bsu-cs!dhesigandalf@csli.Stanford.EDU (Juergen Wagner) (05/14/89)
In article <7195@bsu-cs.bsu.edu> dhesi@bsu-cs.bsu.edu (Rahul Dhesi) writes: >It's a question of whether you "Think VMS" or "Think UNIX". ... >But soon I begin to "Think UNIX" again, and I instead type > cc x; a.out >or better still: > cc x && a.out Even better: use a Makefile. By now, there are also `make' clones available under VMS and other operating systems. Yet, how long did it take until `make' was accepted as a reasonable tool under VMS (by "accepted" I mean "accepted by those who built VMS" - No, no names). UNIX certainly has its deficiencies and problems, and there will always be a non-trivial number of users who will not be satisfied with a particular operating system. However, one thing I especially like about UNIX is the spirit of creating new tools as they are needed. As Rahul mentions, command pipelines, multiple processes, and other concepts which are inherent features of UNIX are often found only rudimentary in other systems (how would I do something like "tbl foo.me | nroff -me | more" without temporary files; why does it take so long to create a subprocess; ...). The elementary principle of function composition is one of the most important features of UNIX. These features are what is needed in a development environment. A production environment (like VMS) may not need them but developing software might be less comfortable (and if one tries to embed UNIX in VMS [Eunice], significant performance problems may arise). [PS: I used the Very Mysterious System for a few years, but have become a highly biased UNIX-user over the last six years. flame/output=NLA0:[0,0]/ignore=world/override=permissions/blocksize=0] -- Juergen Wagner gandalf@csli.stanford.edu wagner@arisia.xerox.com
andy@syma.sussex.ac.uk (Andy Clews) (05/15/89)
From article <7195@bsu-cs.bsu.edu>, by dhesi@bsu-cs.bsu.edu (Rahul Dhesi): > [...useful advice on Thinking Unix instead of Thinking VMS] > > So it's all a question of your state of mind. ^^^^^^^^^^^^^ Severely hallucinogenic, if one constantly switches between VMS and UNIX :-) -- Andy Clews, Computing Service, Univ. of Sussex, Brighton BN1 9QN, ENGLAND JANET: andy@syma.sussex.ac.uk BITNET: andy%syma.sussex.ac.uk@uk.ac Voice: +44 273 606755 ext.2129