From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <bruce.richardson@intel.com> Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id 17ED958D2 for <dev@dpdk.org>; Mon, 3 Nov 2014 15:07:47 +0100 (CET) Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga103.fm.intel.com with ESMTP; 03 Nov 2014 06:10:49 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,308,1413270000"; d="scan'208";a="616021790" Received: from bricha3-mobl3.ger.corp.intel.com ([10.237.220.79]) by fmsmga001.fm.intel.com with SMTP; 03 Nov 2014 06:16:58 -0800 Received: by (sSMTP sendmail emulation); Mon, 03 Nov 2014 14:16:58 +0025 Date: Mon, 3 Nov 2014 14:16:58 +0000 From: Bruce Richardson <bruce.richardson@intel.com> To: "Wiles, Roger Keith" <keith.wiles@windriver.com> Message-ID: <20141103141658.GA6964@bricha3-MOBL3> References: <1414967308-69530-1-git-send-email-keith.wiles@windriver.com> <20141103104129.GA4840@bricha3-MOBL3> <307F2C60-7638-40C8-A9BC-DC3EE3D59F8C@windriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <307F2C60-7638-40C8-A9BC-DC3EE3D59F8C@windriver.com> Organization: Intel Shannon Ltd. User-Agent: Mutt/1.5.23 (2014-03-12) Cc: "dev@dpdk.org" <dev@dpdk.org> Subject: Re: [dpdk-dev] [PATCH] Add external parser support for unknown commands. X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK <dev.dpdk.org> List-Unsubscribe: <http://dpdk.org/ml/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://dpdk.org/ml/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <http://dpdk.org/ml/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> X-List-Received-Date: Mon, 03 Nov 2014 14:07:48 -0000 On Mon, Nov 03, 2014 at 02:08:46PM +0000, Wiles, Roger Keith wrote: > > > On Nov 3, 2014, at 4:41 AM, Bruce Richardson <bruce.richardson@intel.com> wrote: > > > > On Sun, Nov 02, 2014 at 04:28:28PM -0600, Keith Wiles wrote: > >> Allow for a external parser to handle the command line if the > >> command is not found and the developer has called the routine > >> int cmdline_set_external_parser(struct cmdline * cl, > >> cmdline_external_parser_t parser); > >> function to set the function pointer. > >> > >> The function for the external parser function should return CMDLINE_PARSE_NOMATCH > >> if not able to match the command requested or zero is handled. > >> > >> Prototype of external routine: > >> int (*cmdline_external_parser_t)(struct cmdline * cl, const char * buy); > >> > >> Signed-off-by: Keith Wiles <keith.wiles@windriver.com> > > > > Hi Keith, > > > > what is the expected use case for this? Is it for embedding other programming languages alongside the existing DPDK command-line or some other purpose? [Perhaps the use case could be called out in the patch description] > > Hi Bruce, > > I guess the external parser could be used for other programming languages, but the case I was looking at was to provide a default escape from the command line parser to allow my application to handle the commands not understood by the parser. Now that you point it out I could use something like ‘%<line-of-script-code>’ to execute a single line of script code, which is a good idea (thanks). > > One case I am looking at is when you want to execute a command and do not want to add the support into the commands.c file for every possible command. Take the case where you have a bunch of scripts (Lua) in a directory much like a bin directory. Then you could type foo.lua or foo on the command line and execute the foo.lua having the application detect you want to load and run a Lua script after it has finished parsing for the builtin commands. > > For Pktgen I had to add a command called ‘run <filename> <args…>’ to support running a script with arguments. I also needed to add a argvlist type to cmdline to not error out on that command and split up the args into a argv list like format. (Maybe I need to submit that code??) It seemed more straight forward to just pass the command line to the application to run the command. I understand that seems like a minor point, but it does make it easier to use and to support the features I want to support in my PoC. > > Using this method you can just type the name instead of something like ‘run foo.lua’ or just ‘run foo’ and let the code figure out what to run. I have more plans for this features as well and have not finished the basic PoC yet. If you want a peek I can show you what I am working on currently. > > Does this help and do I really need to add all of this to the commit message :-) > Thanks for the explanation. However, if you are looking to have the application handle a bunch of commands itself, why does it need to use the commandline library at all? Why not just have the app handle all the commands instead of some of them? /Bruce