From: rahul <rahul2012@gmail.com>
To: Bart Schaefer <schaefer@brasslantern.com>
Cc: Zsh Users <zsh-users@zsh.org>
Subject: Re: unget a character
Date: Wed, 6 Feb 2013 10:33:09 +0530 [thread overview]
Message-ID: <CACQNQ9NJBR-m7JenqSr4Yc=F=ZtbcbXpMz8OWWYiJszkutQrPQ@mail.gmail.com> (raw)
In-Reply-To: <130205183313.ZM28561@torch.brasslantern.com>
[-- Attachment #1: Type: text/plain, Size: 1173 bytes --]
On Wed, Feb 6, 2013 at 8:03 AM, Bart Schaefer <schaefer@brasslantern.com>wrote:
> On Feb 5, 8:53pm, rahul wrote:
> }
> } How can i unget a character (taken in by read -k).
> }
> } It would help me if i could unget a char in one part of my app, so it
> will
> } be available in the main loop.
>
> If you are talking about an interactive shell reading input with ZLE, you
> can do it with "zle -U".
>
> If you're in some other way reading from a stream such as standard input,
> unget is not possible. You need a lower-level programming language with
> more direct control over things like stdio buffers. (Unget is not an OS-
> level operation, it's implemented in stdio or the equivalent.)
>
I am writing a shell program that uses "read -k" to get keys in a loop (I
have not yet got into zle). It branches off into functions and I wanted to
get a char in one function, and then reject it if it was not correct, so
the main loop could use it.
After asking this question, I realized I could do this programmatically, by
setting the unwanted key to a variable. The main loop would first check the
variable and use that value , if blank it could do a "read".
--
rahul
prev parent reply other threads:[~2013-02-06 7:56 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-05 15:23 rahul
2013-02-06 2:33 ` Bart Schaefer
2013-02-06 5:03 ` rahul [this message]
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