[pve-devel] [PATCH v3 storage 2/3] Incorporate wipe_disks from PVE::Ceph::Tools

[Thomas Lamprecht]

On 4/16/20 8:57 AM, Dominik Csapak wrote:
> 
>>
>>
>> Thanks for clearing that up, I mostly poked at it as Dominic came to me
>> asking what to do as you told him to use [0-9] and Fabian told him to go
>> back again, not knowing about your suggestion.
>>
>> The question is, does the matching of other digit really matters at all?
>>
>> I mean it naturally depends on what happens whit the parsed data, but most
>> of the time it should not really matter at all, or?
>>
> 
> no, most of the time it should not matter at all, but we do parse api
> parameters with decode('utf8', $v) so there is probably some
> path where this could happen...
> 
> mostly i wanted to avoid introducing errors by copy/pasting regexes.
> i really have no idea if this could hit us at all, but
> we use regexes very often and are not very consistent
> with \d and [0-9]
> 
> this is something we should decide on and put it in the style guide
> 
> bottom line: i guess both are ok when used right, but with
> [0-9] there is no ambiguity as to what it matches

If the style guide clears the fact what \d can imply and when it matters
I'd honestly personally prefer \d for all but those case where it really
matters, i.e., where it can have security implications or produce a invalid
config or setup. But I see where you coming from, and IMO it's also fine
to go for [0-9] even if one cannot imagine any negative effect whatsoever.

For now I added a paragraph in the style guide:

https://pve.proxmox.com/wiki/Perl_Style_Guide#Matching_Digits_Fallacy

I hope it's worded OK, feel free to adapt and improve it.