[Toybox] A ps cleanup I can't test...

[Rob Landley]

On 1/14/25 10:36, enh wrote:
> On Sun, Jan 12, 2025 at 3:38 PM Rob Landley <rob at landley.net> wrote:
>>
>> Elliott, could you give this a sniff/smoke test on android? Built with
>> the NDK it's giving blank space for PCY on all the processes I've got,
>> which seems right according to the logic (before and after), but maybe
>> not intentional?
>>
>>     $ cat /proc/self/cgroup
>>     0::/1
>>
>> It's "-" if the file couldn't be opened, but "  " if the file exists but
>> doesn't start with ":cpuset:/"? And then also "  " for
>> "system-background"...
> 
> yeah, i noticed that last time i touched this code and left it because
> i thought it was potentially non-useless given that i spend my life
> remotely debugging unreproducible things and the distinction might be
> a useful clue. but, no, i have no concrete use for this.

I'm not trying to remove it, just want to make sure I didn't 
accidentally break it in a way it wasn't previously broken. :)

> note that the strstart() part is wrong because there's an integer
> before ":cpuset:/" which is why there was a strstr() rather than a
> strcmp() in the original.

Case in point...

> this modified version works correctly though:

I'm assuming your change was just putting the strstr/strlen back?

Alas, no stpstr()...

Hm, if there's _always_ an integer there I could do sscanf(buf, 
"%*u:cpuset:/%n", &j). Except for the part it returns zero even if it 
didn't match because %n doesn't increment the hit count, so I'd have to 
initialize j to 0 and test j being nonzero. Sigh...

(It's just that having the same string constant listed in the source 
twice reads as a rough edge. Even if the compiler is nuts enough to 
resolve the strlen() at compile time, which is not a thing a compiler 
should be doing. Yeah yeah, tiny gripe...)

WHY does man 3 sscanf say that %u is deprecated? Nevermind, I don't want 
to know and will be ignoring it.

Right, stop picking at it, leave the duplicate string for now, commit 
2e9d5017306c lemme know if I broke anything.

Thanks,

Rob