From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: Re: drjones@redhat.com, vkuznets@redhat.com, leiwang@redhat.com, wshi@redhat.com Date: Thu, 24 Apr 2014 10:01:13 +0100 Message-ID: <5358D2D9.6040104@eu.citrix.com> References: <648058658.7316781.1397784467480.JavaMail.zimbra@redhat.com> <1914427839.7319088.1397785246986.JavaMail.zimbra@redhat.com> <53570FCF.9050708@redhat.com> <53579CDC.1050605@eu.citrix.com> <53585763.40105@redhat.com> <1398329070.18537.243.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1398329070.18537.243.camel@kazak.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell , Lingfei Kong Cc: Ian Jackson , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org On 04/24/2014 09:44 AM, Ian Campbell wrote: > On Thu, 2014-04-24 at 08:14 +0800, Lingfei Kong wrote: >> Maybe another solution is to change the xl command to adapt this. > Feel free to propose a patch but I suspect this would involve too much > surgery to the config file parser. > >> On >> RHEL5 xen hypervisor, I can create a guest with `xm create hvm.cfg >> cpus="0-3"`. As a user I prefer this method, because this will be >> consistent with it's config file and it is strange to use ' to enclose >> the parameters. > That is perfectly normal shell quoting behaviour, nothing strange about > it IMHO. Well having the config file syntax include quotes and brackets is natural. The fact that the shell interprets quotes and brackets is also natural. But the combination of the two leads to a rather unexpected and clunky user interface. Unfortunately I'm not sure what we can really do at this point to maintain the general flexibility while avoiding backticks. We might be able to modify the parser for specific cases, such as the cpus one, to tolerate 'cpus=0-3' rather than the canonical 'cpus="0-3"'. But in the general case it would require re-writing the config format such that it can be written without requiring any characters treated specially by the shell; that's just a bit more work than it's really worth, I think. -George