Massive libxo-zation that breaks everything

Harrison Grundy harrison.grundy at
Mon Mar 2 09:28:05 UTC 2015

On 03/02/15 01:23, David Chisnall wrote:
> On 1 Mar 2015, at 21:29, Rui Paulo <rpaulo at> wrote:
>> On Mar 1, 2015, at 11:11, David Chisnall <theraven at>
>> wrote:
>>> How would it be in a port?  It involves modifying core
>>> utilities (some of which, like ifconfig, rely on kernel APIs
>>> that change between releases) to emit structured output.
>>> Maintaining two copies of each utility, one in the base system
>>> with plain-text output only and another in ports with XML/JSON
>>> output would be very painful.
>> It would work fine if we had *libraries* for
>> ifconfig/netstat/route/etc.  Obviously that's not the case and no
>> one has stepped up to implement them.  I've also seen FreeBSD
>> committers expressing their distaste for libraries for "trivial"
>> command line utilities, which implies they are unaware of another
>> world beyond the CLI.  :-)
> I am completely in favour of libraries for the underlying
> functionality of these commands and would love to see all of the
> system management commands become thin wrappers around a library,
> though it's a lot of engineering work.  In particular, these
> libraries will need to have stable APIs that we can support across
> multiple major releases, and getting those right is difficult.  We
> really don't want to be stuck in 10 years maintaining a hastily
> designed API for a library.
> I see one use of the libxo output as helping to design those APIs.
> People are going to wrap various tools in libraries for their
> favourite scripting languages and this will give us a corpus for
> experimenting.
> It's also worth noting that often invoking a tool and consuming its
> output is the easiest way to get a stable API and ABI where
> performance is not a primary concern (i.e. most management
> interfaces).
> As to a world beyond the CLI, I saw a nice demo a few years ago of
> a terminal emulator that used WebKit and came with a hacked-up set
> of parsers for common tools.  I'd love to have something simpler
> (no need for a full WebKit - simple outline and table views would
> be enough and could be done with curses for ssh) for FreeBSD where
> I could type ls in the CLI and get a table view that I could then
> sort and filter by selecting column headings.  Those of us that
> have used Lisp and Smalltalk environments know that a CLI doesn't
> have to be a teletype emulator.
> David

It would seem like the libxo stuff runs the risk of becoming this same

--- Harrison

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