[Rd] R 2.1.1: read.table processes C-style escapes (PR#8037)
Gordon Smyth
smyth at wehi.edu.au
Wed Jul 27 06:20:38 CEST 2005
>To: r-bugs at biostat.ku.dk
>From: Gordon Smyth <smyth at wehi.edu.au>
>Subject: R 2.1.1: read.table processes C-style escapes
>Date: Wed, 27 Jul 2005 12:51:45 +1000
>
>In R 2.1.1, the default behaviour of scan() was changed to process all
>C-style escapes, even when a delimiter was specified using the 'sep'
>argument. A new argument 'allowEscapes' was introduced to turn this
>processing off.
>
>Because read.table() calls scan(), read.table() inherits the new default
>behaviour of scan() but without a way to turn it off. For example, reading
>a file testdata.txt' containing
>
>X
>A
>\0
>C
>
>produces
>
> > read.delim("testdata.txt")
>[1] X
><0 rows> (or 0-length row.names)
>
>It seems that all the occurances of scan() within read.table() need to
>have 'allowEscapes=FALSE' added to the argument string.
Or, alternatively and perhaps better, scan() could regain some of its
earlier behaviour, to process C-style escapes by default only when 'sep' is
NULL or empty. It seems, to me at least, that C-style escape sequences make
sense only in some sort of source code, and delimited text can't be source
code.
Gordon
>Gordon
>
> > version
> _
>platform i386-pc-mingw32
>arch i386
>os mingw32
>system i386, mingw32
>status Patched
>major 2
>minor 1.1
>year 2005
>month 07
>day 22
>language R
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