Messages in this thread | | | Date | Wed, 28 Dec 2022 20:57:04 +0100 | Subject | Re: [oss-security] [patch] proc.5: tell how to parse /proc/*/stat correctly | From | Alejandro Colomar <> |
| |
Hi all,
On 12/28/22 20:24, Shawn Webb wrote: > On Wed, Dec 28, 2022 at 01:02:35PM -0500, Demi Marie Obenour wrote: >> On Wed, Dec 28, 2022 at 12:25:17PM -0500, Shawn Webb wrote: >>> On Wed, Dec 28, 2022 at 11:47:25AM -0500, Demi Marie Obenour wrote: >>>> On Wed, Dec 28, 2022 at 10:24:58AM -0500, Shawn Webb wrote: >>>>> On Tue, Dec 27, 2022 at 04:44:49PM -0800, Lyndon Nerenberg (VE7TFX/VE6BBM) wrote: >>>>>> Dominique Martinet writes: >>>>>> >>>>>>> But, really, I just don't see how this can practically be said to be parsable... >>>>>> >>>>>> In its current form it never will be. The solution is to place >>>>>> this variable-length field last. Then you can "cut -d ' ' -f 51-" >>>>>> to get the command+args part (assuming I counted all those fields >>>>>> correctly ...) >>>>>> >>>>>> Of course, this breaks backwards compatability. >>>>> >>>>> It would also break forwards compatibility in the case new fields >>>>> needed to be added. >>>>> >>>>> The only solution would be a libxo-style feature wherein a >>>>> machine-parseable format is exposed by virtue of a file extension. >>>>> >>>>> Examples: >>>>> >>>>> 1. /proc/pid/stats.json >>>>> 2. /proc/pid/stats.xml >>>>> 3. /proc/pid/stats.yaml_shouldnt_be_a_thing >>>> >>>> A binary format would be even better. No risk of ambiguity. >>> >>> I think the argument I'm trying to make is to be flexible in >>> implementation, allowing for future needs and wants--that is "future >>> proofing". >> >> Linux should not have an XML, JSON, or YAML serializer. Linux already >> does way too much; let’s not add one more thing to the list. > > Somewhat agreed. I think formats like JSON provide a good balance > between machine parseable and human readable. > a > As I described earlier, though, when it comes to concepts like procfs > and sysfs, I have a bias towards abandoning them in favor of sysctl. > If sysctl nodes were to be used, no new serialization formats would > need to be implemented--and developers would also use a safter method > of system and process inspection and manipulation. >
Just a comment as someone who is reading without much understanding of the contents of /prod/pid/stat:
If organization of the data in the file is a problem, and the format starts to matter, maybe it's a hint that there are too many different contents, and could be split into different files, each one with its own formatting rules. I'll suggest that maybe a set of files, maybe contained in a common directory stats.d, is what you're looking for?
Binary format is not of my preference, since most user-space tools work with the standard interface, that is, text.
Cheers,
Alex
-- <http://www.alejandro-colomar.es/> [unhandled content-type:application/pgp-signature] | |