zsh-workers
 help / color / mirror / code / Atom feed
From: Stephane Chazelas <stephane.chazelas@gmail.com>
To: zsh-workers@zsh.org
Subject: Re: lstat(2) upon e and + globbing qualifiers
Date: Fri, 21 Feb 2020 19:45:32 +0000	[thread overview]
Message-ID: <20200221194532.bp7imfxvybjgaogs@chazelas.org> (raw)
In-Reply-To: <20121109121237.GA11082@chaz.gmail.com>

Ping:

2012-11-09 12:12:37 +0000, Stephane Chazelas:
Adding a "e" or "+" qualifier to a globbing pattern seems to
cause zsh to call an unnecessary lstat(2) for each file. No big
deal, just potential performance improvement here.

There's a side effect though when you have read but not search
permission on a directory:

$ strace -fe lstat zsh -c 'echo 2/*'
2/bar 2/foo
$ strace -fe lstat zsh -c 'echo 2/*(e::)'
lstat("2/foo", 0x7fff95492110)          = -1 EACCES (Permission denied)
lstat("2/bar", 0x7fff95492110)          = -1 EACCES (Permission denied)
zsh:1: no matches found: 2/*(e::)

(reproduced with 5.0 on debian)

-- 
Stephane

      reply	other threads:[~2020-02-21 19:46 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-09 12:12 Stephane Chazelas
2020-02-21 19:45 ` Stephane Chazelas [this message]

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=20200221194532.bp7imfxvybjgaogs@chazelas.org \
    --to=stephane.chazelas@gmail.com \
    --cc=zsh-workers@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).