zsh-users
 help / color / mirror / code / Atom feed
From: Vincent Lefevre <vincent@vinc17.net>
To: zsh-users@zsh.org
Subject: Re: detect pipe
Date: Sun, 14 Feb 2021 18:31:38 +0100	[thread overview]
Message-ID: <20210214173138.GA2298446@zira.vinc17.org> (raw)
In-Reply-To: <CAH+w=7aXd5i5vz5k++-4G=Ow4VfYE2q_s2dGLKHK_zG=Ox1VVQ@mail.gmail.com>

On 2021-01-30 11:00:15 -0800, Bart Schaefer wrote:
> On Sat, Jan 30, 2021 at 6:27 AM Ray Andrews <rayandrews@eastlink.ca> wrote:
> >
> > Cool stuff Bart.  Would you please elaborate on 'Close stdin'?
> 
> ubuntu% ls /dev/fd/0
> /dev/fd/0
> ubuntu% ls /dev/fd/0 <&-
> ls: cannot access '/dev/fd/0': No such file or directory
> 
> File descriptor zero, the standard input, has been closed; it
> literally does not exist for "ls" (in this example).  If it's closed,
> it's not possible to read from it:
> 
> ubuntu% cat <&-
> cat: -: Bad file descriptor
> cat: closing standard input: Bad file descriptor
> 
> Most commands will ignore a closed stdin and behave similarly to
> reading from /dev/null.

Closing stdin is a bad idea, as this can break stdout redirection,
and this may be out of control of the commands. See

  https://sourceware.org/bugzilla/show_bug.cgi?id=682

-- 
Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)


  parent reply	other threads:[~2021-02-14 17:32 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-27 16:45 Ray Andrews
2021-01-27 23:59 ` Bart Schaefer
2021-01-28  4:57   ` Ray Andrews
2021-01-28  6:16     ` Bart Schaefer
2021-01-28 10:08     ` Vincent Lefevre
2021-01-28 10:28       ` Vincent Lefevre
2021-01-28 15:05         ` Ray Andrews
2021-01-28 15:45           ` Ray Andrews
2021-01-28 20:58             ` Bart Schaefer
2021-01-28 20:59               ` Bart Schaefer
2021-01-29  1:17               ` Ray Andrews
2021-01-29  2:50                 ` Bart Schaefer
2021-01-29  3:21                   ` Ray Andrews
2021-01-30  0:29                     ` Bart Schaefer
2021-01-30 14:26                       ` Ray Andrews
2021-01-30 19:00                         ` Bart Schaefer
2021-01-30 19:19                           ` Ray Andrews
2021-01-31 19:12                             ` Ray Andrews
2021-01-31 21:28                               ` Bart Schaefer
2021-02-14 17:31                           ` Vincent Lefevre [this message]
2021-02-14 19:33                             ` Bart Schaefer
2021-02-14 20:33                               ` Ray Andrews
2021-02-14 21:20                                 ` Bart Schaefer
2021-02-14 22:25                                   ` Ray Andrews
2021-02-14 21:24                                 ` Vincent Lefevre
2021-02-14 21:19                               ` Vincent Lefevre
2021-02-14 21:24                                 ` Bart Schaefer
2021-02-14 21:38                                 ` Bart Schaefer

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210214173138.GA2298446@zira.vinc17.org \
    --to=vincent@vinc17.net \
    --cc=zsh-users@zsh.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://git.vuxu.org/mirror/zsh/

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).