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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id C03A1C433EF for ; Wed, 20 Jul 2022 16:31:49 +0000 (UTC) Received: from localhost ([::1]:48584 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oECc0-0006ov-RN for qemu-devel@archiver.kernel.org; Wed, 20 Jul 2022 12:31:48 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51554) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oECaK-00062w-6k for qemu-devel@nongnu.org; Wed, 20 Jul 2022 12:30:04 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:50863) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oECaH-00083t-9Z for qemu-devel@nongnu.org; Wed, 20 Jul 2022 12:30:02 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1658334600; 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: in-reply-to:in-reply-to:references:references; bh=haltGnPRwHX7Y0FLVNo72kYeJDi5HGmvFGwieKo/+XI=; b=CuQo3G3FwFy3m+msXl18nxN02JvXCB4BJFqVvZ8YFO6yBlGsdpTVFH6OTrpn+XSzgMIx/F E0msMAjWDwHz0rhFnKjQD70uaW0sRp0staZnU+Jcjh0WJgSExYjzawTffgnKvNOHVD6Jpc K9mYeLfcjI8xqn+cB1msJcDEN1GJd88= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-163-v0F6P3WEMRKBSXdQJMJZ2w-1; Wed, 20 Jul 2022 12:29:56 -0400 X-MC-Unique: v0F6P3WEMRKBSXdQJMJZ2w-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7A4FB85A58C; Wed, 20 Jul 2022 16:29:56 +0000 (UTC) Received: from redhat.com (unknown [10.2.16.94]) by smtp.corp.redhat.com (Postfix) with ESMTPS id DA48440C1288; Wed, 20 Jul 2022 16:29:55 +0000 (UTC) Date: Wed, 20 Jul 2022 11:29:54 -0500 From: Eric Blake To: Peter Maydell Cc: qemu-devel@nongnu.org, Paolo Bonzini , "Dr. David Alan Gilbert" , Thomas Huth , Richard Henderson Subject: Re: [PATCH 3/5] configure: Don't use bash-specific string-replacement syntax Message-ID: <20220720162954.hzrv4ypgobcgwmeu@redhat.com> References: <20220720152631.450903-1-peter.maydell@linaro.org> <20220720152631.450903-4-peter.maydell@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220720152631.450903-4-peter.maydell@linaro.org> User-Agent: NeoMutt/20220429 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 Received-SPF: pass client-ip=170.10.129.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01, WEIRD_QUOTING=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Jul 20, 2022 at 04:26:29PM +0100, Peter Maydell wrote: > The variable string-replacement syntax ${var/old/new} is a bashism > (though it is also supported by some other shells), and for instance > does not work with the NetBSD /bin/sh, which complains: > ../src/configure: 687: Syntax error: Bad substitution > > Replace it with a more portable sed-based approach, similar to > what we already do in quote_sh(). > > for e in $1; do > - e=${e/'\'/'\\'} > - e=${e/\"/'\"'} > - printf '"""%s""",' "$e" > + printf '"""' > + # backslash escape any '\' and '"' characters > + printf "%s" "$e" | sed -e 's/\([\"]\)/\\\1/g' You've fixed the bashism, but at the expense of a non-POSIX use of sed. POSIX says the input to sed must be a text file (ending in a newline; but $e does not), and as a result it always outputs a newline (but you don't want a newline before the closing """). GNU sed happens to do what you want for input not ending in a newline, but I don't remember off-hand whether BSD sed does, and I know that Solaris sed does not. If this passes on BSD, then I'm okay with it; but if we want to avoid non-POSIX altogether, this should work (using the shell's $() to strip the trailing newline we added to keep sed happy): # backslash escape any '\' and '"' characters printf '"""%s""",' "$(printf "%s\n" "$e" | sed -e '/s/\([\"]\)/\\\1/g')" Your call. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org