Re: An alternative way of populating /proc

[H. Peter Anvin]

Followup to:  <[e-mail]>
By author:    Matt Aubury <[e-mail]>
In newsgroup: linux.dev.kernel
> 
> Hi,
> 
> The recent debate about the multitude of possible formats for data in
> /proc caused me to think about a short-hand way of populating a /proc
> directory hierarchy. This scheme uses a format string to describe the
> hierarchical data layout, so:
> 
> 	create_proc_entries(NULL,
> 		"test:{bar:{x:%d,y:%d,z:%d},foo:%f}",
> 		&x, &y, &z, foo_fun);
> 
> creates a "/proc/test" directory, which further contains a
> subdirectory "bar" and a file "foo". The "bar" subdirectory contains
> three files "x", "y" and "z".
> 
> The formatting argument "%d" takes a pointer to an integer. When
> reading such a file (in this case "x", "y", or "z"), the value is
> shown as ascii. Writing to the file (again in ascii) updates the
> value. The "%f" formatting argument allows you to pass an arbitrary
> user function for generating output. Clearly, there are potentially
> quite a number of standard/useful formatting arguments.
> 

This is more or less what I had in mind, but we do need a little more
than that.  Part of the problem with the existing /proc is that it is
nice for humans, but is downright difficult to parse by machine.
/proc/sys is a lot better, but the kernel-internal APIs are horrible.

I had a discussion with Stephen Tweedie about this the other day.  I
will try to write up what we came up with tomorrow or so.

     -hpa
-- 
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"Unix gives you enough rope to shoot yourself in the foot."