[Gnu-arch-users] Features command for arch

[James Blackwell]

ddaa and I put our heads together not long ago, and we came up with a new
feature that would probably help programs like pyarch and aba. This new
command, called "tla features" would list features and feature version
numbers. One could also query either for a specific feature, or a specific
version of a feature. Please see the example output at the end of this
email.

How it will work: 

There's the easy way to do this, and the hard way to do this. I'm inclined
to implement the easy way. The easy way is to in libarch implement a
handful of arch_features functions along these lines: 

int arch_feature_query (t_uchar *featureid)
  returns the feature # for the requested feature, 0 if feature does not
  exist
  
rel_table arch_features_get 
  returns a rel_table of arch features, of which each entry contrains:
  "feature_name:version"


The list of features and versions will be kept in a simple null terminated
array.


EXAMPLE OUTPUT:
$ tla features
tla-features-begin
file-id-escaping:1
archive-checksums:2
tla-features-end
(always a return code of 0)

$ tla features file-id-escaping
1
(with a return code of 0)

$ tla features archive-checksums 
2
(return code of 0)

$ tla features archive-checksums 1
(return code of 0)

$ tla features archive-checksums 3
(return code of 1)

$ tla features nonexistant-feature
(return code of 1)



-- 
James Blackwell          Try something fun: For the next 24 hours, give
Smile more!              each person you meet a compliment!

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