X-Recipient: archive-cygwin@delorie.com X-Original-To: cygwin@cygwin.com Delivered-To: cygwin@cygwin.com DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 0EEC83857C62 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=optusnet.com.au Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=dunc@dimstar.local.net Date: Thu, 25 Feb 2021 09:41:49 +1100 From: Duncan Roe To: cygwin@cygwin.com Subject: Re: Tee and file redirections are very slow to write anything. Message-ID: <20210224224149.GM2979@dimstar.local.net> Mail-Followup-To: cygwin@cygwin.com References: <87eeh5b39n.fsf@Otto.invalid> <49e01de1-f7de-5d60-2996-3c9afb834396@cs.umass.edu> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <49e01de1-f7de-5d60-2996-3c9afb834396@cs.umass.edu> User-Agent: Mutt/1.10.1 (2018-07-13) X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=YKPhNiOx c=1 sm=1 tr=0 cx=a_idp_d a=RYlFDMs+IEYG30eBDFJ7ng==:117 a=RYlFDMs+IEYG30eBDFJ7ng==:17 a=kj9zAlcOel0A:10 a=qa6Q16uM49sA:10 a=RSmzAf-M6YYA:10 a=VLfUi0mRK4W4aE3CML0A:9 a=CjuIK1q_8ugA:10 X-Spam-Status: No, score=-4.5 required=5.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, KAM_DMARC_STATUS, RCVD_IN_DNSWL_LOW, SPF_FAIL, SPF_HELO_PASS, TXREP autolearn=no 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@cygwin.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: General Cygwin discussions and problem reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: cygwin-bounces@cygwin.com Sender: "Cygwin" On Wed, Feb 24, 2021 at 04:58:24PM -0500, Eliot Moss wrote: > On 2/24/2021 3:48 PM, ASSI wrote: > > Hamish McIntyre-Bhatty via Cygwin writes: > > > I found recently when trying to save output from a script for later > > > inspection that "tee" and file redirections seem to have massive > > > delays when run in Cygwin - usually nothing is written to file or > > > stdout until after the command has finished - not very helpful. > > > > You will want to switch from fully buffered to line-buffered or even > > unbuffered output. > > And this does not have to do with Cygwin. The same happens on Linux. > The default is that terminal I/O is unbuffered while other stream are > buffered. Pipes come under "other streams". One can make programmatic > changes to get around this, but most programs won't override the > default behavior on their own ... > > Best -- Eliot Moss The (Linux) default is that terminal I/O is *line* buffered The man page for tee doesn't show an option to change buffering, while that for grep does. Cheers ... Duncan. -- 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