[R] how to read/save .zip compressed files from R?

[Prof Brian Ripley]

See also Omegahat package Rcompression (a copy of which for Windows is 
on CRANextras).

But I would do this via unzip, modify, zip

On Tue, 3 Aug 2010, Jeff Newmiller wrote:

> In the way you describe it, no.
>
> A) There is no such thing as a "zip folder". You are most likely 
> being fooled by the visual presentation of zip files in Windows 
> Explorer, which automatically simulates it as a folder, when it is 
> really extracting bits of data as needed to display it.
>
> B) Because the data must be decompressed to be manipulated, there is 
> no performance or disk space advantage to creating a facility such 
> as you describe, though thee may be a convenience factor if you do 
> it a lot.
>
> C) There is a function zip.file.extract() in R for extraction, but I 
> don't see a zip compression function, so you will need to use 
> external programs, perhaps executed using the "system" function, to 
> generate updated zip files.

You both missed utils::unzip.

> D) It is almost always a bad idea to overwrite your original data, 
> since this prevents you from retracing your data processing steps 
> later for verification or debugging purposes.
>
> J.delasHeras at ed.ac.uk wrote:
>
>>
>> Dear list,
>>
>> is there a way to open a .zip folder so that one can extract and
>> modify files inside and then save teh .zip folder again?
>>
>> thanks!
>>
>> Jose
>>
>> --
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>
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-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
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