From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <zsh-users-return-24003-ml=inbox.vuxu.org@zsh.org>
X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on inbox.vuxu.org
X-Spam-Level: 
X-Spam-Status: No, score=-1.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID,
	DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham
	autolearn_force=no version=3.4.2
Received: from primenet.com.au (ns1.primenet.com.au [203.24.36.2])
	by inbox.vuxu.org (OpenSMTPD) with ESMTP id 9eb771f9
	for <ml@inbox.vuxu.org>;
	Wed, 3 Jul 2019 13:59:20 +0000 (UTC)
Received: (qmail 741 invoked by alias); 3 Jul 2019 13:59:07 -0000
Mailing-List: contact zsh-users-help@zsh.org; run by ezmlm
Precedence: bulk
X-No-Archive: yes
List-Id: Zsh Users List <zsh-users.zsh.org>
List-Post: <mailto:zsh-users@zsh.org>
List-Help: <mailto:zsh-users-help@zsh.org>
List-Unsubscribe: <mailto:zsh-users-unsubscribe@zsh.org>
X-Seq: 24003
Received: (qmail 9301 invoked by uid 1010); 3 Jul 2019 13:59:06 -0000
X-Qmail-Scanner-Diagnostics: from aurora-borealis.phear.org by f.primenet.com.au (envelope-from <eiro@phear.org>, uid 7791) with qmail-scanner-2.11 
 (clamdscan: 0.101.2/25496. spamassassin: 3.4.2.  
 Clear:RC:0(94.242.205.164):SA:0(-2.0/5.0):. 
 Processed in 2.65968 secs); 03 Jul 2019 13:59:06 -0000
X-Envelope-From: eiro@phear.org
X-Qmail-Scanner-Mime-Attachments: |
X-Qmail-Scanner-Zip-Files: |
Received-SPF: pass (ns1.primenet.com.au: SPF record at phear.org designates 94.242.205.164 as permitted sender)
X-Virus-Scanned: amavisd-new at phear.org
DKIM-Filter: OpenDKIM Filter v2.10.3 aurora-borealis.phear.org EBF71FFD6
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=phear.org;
	s=20180217; t=1562162306;
	bh=dSaCKFxRgybVaucL96aTbzsIdCeeV88+SS/UPlZHvKA=;
	h=Date:From:To:Subject:From;
	b=UGrblxVgKdjEdul0afM8FQ7U+7Lwz0uwCFv6QF/i9ZofF06mXrmMaB7qNPX1PIS8L
	 MCKno8cvZTXhemnuEIBxYNnPJDcnweS7xgG2qtDWEfCKflIBkcaduiM0fvOxqz/XU3
	 XsBdrG8DS5FKVEtEZ1zYxa+daHMkhYebW5I28KFzBIlG/Z7rj9Fa4ysZicBzHQbcXG
	 282hUUeWa9pOAM89vT+Xsv0hpgtDfNpS4qof8JZpZgGzBapnYBSvipQOlm2Bz8N8GB
	 ekqGA2JDvZNtmb31M6WMakkZ9NB3XFVlFRBNfcMCh2De4qOUu0YAlOqE3JYt+V9GDF
	 6GHhRyb8hPLUA==
Date: Wed, 3 Jul 2019 15:58:24 +0200
From: Marc Chantreux <eiro@phear.org>
To: Zsh Users <zsh-users@zsh.org>
Subject: zsh poor performances while reading and testing ?
Message-ID: <20190703135824.GA19289@prometheus.u-strasbg.fr>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.10.1 (2018-07-13)

hello people,

i recently made a benchmark to emphasize the gain of speed
people can have using filters instead of pure shell loops.
however i was surprised to see how slow zsh is compared to
other shells when it comes to read data.

the interesting part of the benchmark is:

  for it (bash zsh ksh) {
    TIMEFMT=": $it %U %S %E"
    time $it  -c 'while read it; do : ; done < x > /dev/null'
  }

: bash 4,95s 1,21s 6,18s
: zsh 12,65s 28,12s 40,82s
: ksh 9,87s 26,52s 36,42s

is there any obvious reason for that? is there a way to make
it faster without diving in the C code?

regards,
marc