From edd at debian.org  Sun Feb  1 02:50:08 2004
From: edd at debian.org (Dirk Eddelbuettel)
Date: Sun Feb  1 02:50:19 2004
Subject: [Rd] bzfile() in R
In-Reply-To: <401C5841.5090500@jhsph.edu>
References: <401C5841.5090500@jhsph.edu>
Message-ID: <20040201015007.GA8052@sonny.eddelbuettel.com>

On Sat, Jan 31, 2004 at 08:37:05PM -0500, Roger D. Peng wrote:
> I'm putting together a data package and am finding that I get 
> enormous savings in space by using bzip instead of the usual gzip 
> in save().  Is it safe to assume that for R versions, say >= 
> 1.7.1, that the function bzfile() will always be available?

I don't think that is correct as this an optional compile-team feature.

help(bzfile) says it 'may' be present whereas gzfile is guaranted (from a
1.9.0 snapshot):

     All platforms support (gz)file connections and 'url("file://")'
     connections.  The other types may be partially implemented or not
     implemented at all.  (They do work on most Unix platforms, and all
     but 'fifo' on Windows.)
		    
but then goes on to say under See Also:

     'capabilities' to see if 'gzfile', 'url', 'fifo' and
     'socketConnection' are supported by this build of R.

which suggests that even gzfile may not be guaranteed.

You could of course test via capabilities() and abort with a clear error.

Dirk

-- 
The relationship between the computed price and reality is as yet unknown.  
                                             -- From the pac(8) manual page


[Rd] bzfile() in R
Dirk Eddelbuettel