From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51533C433DB for ; Tue, 19 Jan 2021 20:53:56 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id BF978206EC for ; Tue, 19 Jan 2021 20:53:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BF978206EC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:44720 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l1y0g-00031w-OX for qemu-devel@archiver.kernel.org; Tue, 19 Jan 2021 15:53:54 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:45718) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l1xDV-0002v9-KP for qemu-devel@nongnu.org; Tue, 19 Jan 2021 15:03:07 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:60101) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l1xDO-00053F-LU for qemu-devel@nongnu.org; Tue, 19 Jan 2021 15:03:04 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611086577; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=khsJiiDVzqhi+f3Klq5RPknJMwYgzRVFwNSG4UOmci8=; b=MADLq0WAhqf7xdTuprncKjAe7sK1+pci+JciqyfWIb8Np0qt9ncr1Qma9A+DweCn3MGDGk hwvpygOf9PcqG76RTnUYVZHEeaS9BA0vYBfUUFIyeQBjmnOIM5IkGPOT3Rph448COGIK0n 3fyGTCn2rTYlJBN4oGiKVvGj60wzMLU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-243-4Ulrpz7FPWWps1QUr5_3XQ-1; Tue, 19 Jan 2021 15:02:52 -0500 X-MC-Unique: 4Ulrpz7FPWWps1QUr5_3XQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B1C16427C2; Tue, 19 Jan 2021 20:02:51 +0000 (UTC) Received: from [10.10.120.151] (ovpn-120-151.rdu2.redhat.com [10.10.120.151]) by smtp.corp.redhat.com (Postfix) with ESMTP id 41A149935; Tue, 19 Jan 2021 20:02:51 +0000 (UTC) Subject: Re: [PATCH] qmp-shell: Suppress banner and prompt when stdin is not a TTY To: Dov Murik , qemu-devel@nongnu.org References: <20210117072742.119377-1-dovmurik@linux.vnet.ibm.com> From: John Snow Message-ID: Date: Tue, 19 Jan 2021 15:02:50 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20210117072742.119377-1-dovmurik@linux.vnet.ibm.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jsnow@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=jsnow@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.195, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Markus Armbruster Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 1/17/21 2:27 AM, Dov Murik wrote: > Detect whether qmp-shell's standard input is not a TTY; in such case, > assume a non-interactive mode, which suppresses the welcome banner and > the "(QEMU)" prompt. This allows for easier consumption of qmp-shell's > output in scripts. > > Example usage before this change: > > $ printf "query-status\nquery-kvm\n" | sudo scripts/qmp/qmp-shell qmp-unix-sock > Welcome to the QMP low-level shell! > Connected to QEMU 5.1.50 > > (QEMU) {"return": {"status": "running", "singlestep": false, "running": true}} > (QEMU) {"return": {"enabled": true, "present": true}} > (QEMU) > > Example usage after this change: > > $ printf "query-status\nquery-kvm\n" | sudo scripts/qmp/qmp-shell qmp-unix-sock > {"return": {"status": "running", "singlestep": false, "running": true}} > {"return": {"enabled": true, "present": true}} > > Signed-off-by: Dov Murik Hiya! I've been taking lead on modernizing a lot of our python infrastructure, including our QMP library and qmp-shell. (Sorry, not in MAINTAINERS yet; but I am in the process of moving these scripts and tools over to ./python/qemu/qmp.) This change makes me nervous, because qmp-shell is not traditionally a component we've thought of as needing to preserve backwards-compatible behavior. Using it as a script meant to be consumed in a headless fashion runs a bit counter to that assumption. I'd be less nervous if the syntax of qmp-shell was something that was well thought-out and rigorously tested, but it's a hodge-podge of whatever people needed at the moment. I am *very* reluctant to cement it. Are you trying to leverage the qmp.py library from bash? --js > --- > > Notes: > Note that this might be considered a breaking change; if users have > automated scripts which assume that qmp-shell prints 3 lines of banner, > this change will break their scripts. If there are special > considerations/procedures for breaking changes, please let me know. > > The rationale behaind the TTY check is to imitate python's behaviour: > > $ python3 > Python 3.7.5 (default, Apr 19 2020, 20:18:17) > [GCC 9.2.1 20191008] on linux > Type "help", "copyright", "credits" or "license" for more information. > >>> print(19+23) > 42 > >>> > > $ echo 'print(19+23)' | python3 > 42 > > scripts/qmp/qmp-shell | 19 +++++++++++++++++-- > 1 file changed, 17 insertions(+), 2 deletions(-) > > diff --git a/scripts/qmp/qmp-shell b/scripts/qmp/qmp-shell > index b4d06096ab..9336066fa8 100755 > --- a/scripts/qmp/qmp-shell > +++ b/scripts/qmp/qmp-shell > @@ -288,6 +288,8 @@ class QMPShell(qmp.QEMUMonitorProtocol): > self.__completer_setup() > > def show_banner(self, msg='Welcome to the QMP low-level shell!'): > + if not self._interactive: > + return > print(msg) > if not self._greeting: > print('Connected') > @@ -300,6 +302,15 @@ class QMPShell(qmp.QEMUMonitorProtocol): > return "TRANS> " > return "(QEMU) " > > + def read_command(self, prompt): > + if self._interactive: > + return input(prompt) > + else: > + line = sys.stdin.readline() > + if not line: > + raise EOFError > + return line > + > def read_exec_command(self, prompt): > """ > Read and execute a command. > @@ -307,7 +318,7 @@ class QMPShell(qmp.QEMUMonitorProtocol): > @return True if execution was ok, return False if disconnected. > """ > try: > - cmdline = input(prompt) > + cmdline = self.read_command(prompt) > except EOFError: > print() > return False > @@ -322,6 +333,9 @@ class QMPShell(qmp.QEMUMonitorProtocol): > def set_verbosity(self, verbose): > self._verbose = verbose > > + def set_interactive(self, interactive): > + self._interactive = interactive > + > class HMPShell(QMPShell): > def __init__(self, address): > QMPShell.__init__(self, address) > @@ -449,8 +463,9 @@ def main(): > except qemu.error: > die('Could not connect to %s' % addr) > > - qemu.show_banner() > qemu.set_verbosity(verbose) > + qemu.set_interactive(sys.stdin.isatty()) > + qemu.show_banner() > while qemu.read_exec_command(qemu.get_prompt()): > pass > qemu.close() >