[R] gzfile with multiple entries in the archive

[Prof Brian Ripley]

On Tue, 14 Nov 2006, John James wrote:

> If I open a tgz archive with gzfile and then parse it using readLines I miss
> the initial line of each member of the archive - and also the name of the
> file although the archive otherwise complete (but useless!).

You can use a gzfile connection to read the underlying .tar file, but that 
is not a text file and you will need to pick its structure apart yourself 
via readBin and readChar.

> Is there any way within R to extract both the list of files in a tgz archive
> and to extract any one of these files?

> Clearly I can use zcat and tar on Linux, but I need this to work within the
> R environment on Windows!

You could use tar on Windows: it is in the R tools set.

-- 
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)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595