X-Recipient: archive-cygwin AT delorie DOT com
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 18011394EC17
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com;
	s=default; t=1613292280;
	bh=YVwmEpx5ZCJYmTrglFMIrGcLldRbg2/K7QwtrkorrpU=;
	h=Date:To:Subject:In-Reply-To:References:List-Id:List-Unsubscribe:
	 List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc:
	 From;
	b=JoA1KMFBkz9LSC8xZV1NAtNtYOwX6wFzZqVVbo2KZPOLR39qD8+cjuAS45I4qivoP
	 byhiQuE8C1hdg3xOJ2ohJO2ln8VK0c4qPJ+tPOR/f924advk+Nv5RwZwzlvjFX7H+1
	 qOIAguLisO9CMsQKrH9EpOFl6JyyR0utR3AMK+iM=
X-Original-To: cygwin AT cygwin DOT com
Delivered-To: cygwin AT cygwin DOT com
DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 25FEC394EC17
DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-04.nifty.com 11E8hwjp031104
X-Nifty-SrcIP: [118.243.85.178]
Date: Sun, 14 Feb 2021 17:43:58 +0900
To: cygwin AT cygwin DOT com
Subject: Re: Cygwin doesn't handle SIGWINCH properly in Windows Terminal
Message-Id: <20210214174358.f828f285a566846254c3c54a@nifty.ne.jp>
In-Reply-To: <CABPP8W9h=LzUGf=JP-2x3SjrBPh8NJuoRbXzRU94b-WfBt94yw@mail.gmail.com>
References: <CABPP8W9h=LzUGf=JP-2x3SjrBPh8NJuoRbXzRU94b-WfBt94yw AT mail DOT gmail DOT com>
X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.30; i686-pc-mingw32)
Mime-Version: 1.0
X-Spam-Status: No, score=-3.6 required=5.0 tests=BAYES_00, DKIM_SIGNED,
 DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, NICE_REPLY_A, RCVD_IN_DNSWL_NONE,
 SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2
X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on
 server2.sourceware.org
X-BeenThere: cygwin AT cygwin DOT com
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Unsubscribe: <https://cygwin.com/mailman/options/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=unsubscribe>
List-Archive: <https://cygwin.com/pipermail/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-request AT cygwin DOT com?subject=help>
List-Subscribe: <https://cygwin.com/mailman/listinfo/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=subscribe>
From: Takashi Yano via Cygwin <cygwin AT cygwin DOT com>
Reply-To: Takashi Yano <takashi DOT yano AT nifty DOT ne DOT jp>
Cc: Alvin Seville <alvinseville7cf AT gmail DOT com>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Errors-To: cygwin-bounces AT cygwin DOT com
Sender: "Cygwin" <cygwin-bounces AT cygwin DOT com>

On Sat, 13 Feb 2021 20:39:39 +1000
Alvin Seville wrote:
> Windows build number: Win32NT 10.0.19042.0 Microsoft Windows NT 10.0.19042.0
> Windows Terminal version (if applicable): 1.5.10271.0
> 
> Script to reproduce this issue:
> 
> #!/usr/bin/env bashfunction outputText()
> {
>   local text=$1
>   local -i textLength=${#text}
> 
>   local -i line="$(tput lines) / 2"
>   local -i col="$(tput cols) / 2 - $textLength / 2"
> 
>   clear
>   echo -en "\e[$line;${col}H$text"
> }
> trap "outputText 'Hello world!'" SIGWINCH
> 
> outputText 'Hello world!'while truedo
>     :done

This is because cygwin console handles SIGWINCH when the input
messages is processed. If the process does not call either read()
or select(), SIGWINCH will not be sent. This is the long standing
problem of the implementation and hard to fix.

Therefore, I expect the following code should work, however I
have noticed it does not.

#!/usr/bin/env bash
function outputText()
{
  local text=$1
  local -i textLength=${#text}

  local -i line="$(tput lines) / 2"
  local -i col="$(tput cols) / 2 - $textLength / 2"

  clear
  echo -en "\e[$line;${col}H$text"
}

trap "outputText 'Hello world!'" SIGWINCH

outputText 'Hello world!'
while true
do
  read # <- Call read here
done

This seems to be a bug of console code. I will submit a patch
for this issue.

-- 
Takashi Yano <takashi DOT yano AT nifty DOT ne DOT jp>
--
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple