Re: [Bug-tar] Tar's --xattrs | --selinux | --acls listing feature

[Tim Kientzle]

On May 3, 2012, at 11:27 AM, Andreas Dilger wrote:

> On 2012-05-03, at 6:10 AM, Pavel Raiskup wrote:
>>> Something like that looks reasonable.
>>> One major comment, though, is that the output of
>>> tar should be parsable, i.e., it should be possible
>>> to look at the output, figure out what format it is,
>>> and parse it reliably.  The current format doesn't have
>>> that property, but these extended formats ought to, no?
>> 
>> I'm not sure if I follow you correctly -- you mean some 'universal' parser 
>> that gets tar's -t output and parses it alway correctly and gets as much 
>> info as possible?
>> 
>> IIUC -- In previous proposal it is not so easy to achieve this goal in
>> case that there is the 'vv' (not 'vvv') output requested.  There may occur 
>> some ambiguity between --xattrs lines and --acls "added" lines, yes?
>> 
>> .. other possibility is to add two bytes -- 'CHARACTER COLON' before each
>> additional line.  Extended attributes e.g. "x:" for --xattrs, "a:" for
>> --acls and "s:" for security context.  Again -- the 'vvv' is not needed
>> now and even its header can go out.  Or ..
>> 
>> .. do you (or other listener of this channel) see even other better
>> solution?
> 
> If you are looking for an output format that is relatively easy for humans to 
> read, but is still well formatted and machine parseable, please consider 
> using YAML.  This is a colon-delimited text format, similar to what you 
> propose above, but has a few more features.  There are YAML parsers for 
> virtually every language, so should be considered as the first choice of 
> machine-readable textual output, rather than inventing some new format.

YAML would be reasonable, or JSON or XML.
I'm not very particular.

I would like to see a written proposal for such a format.
If it looks reasonable, we could easily add it to bsdtar
as well.

Cheers,

Tim