From ligges at statistik.tu-dortmund.de  Tue Apr  8 13:21:51 2008
From: ligges at statistik.tu-dortmund.de (Uwe Ligges)
Date: Tue, 08 Apr 2008 13:21:51 +0200
Subject: [Rd] "\0" gives no warning "unknown escape sequence" (PR#11107)
In-Reply-To: <20080407211005.00AA8282EFF7@mail.pubhealth.ku.dk>
References: <20080407211005.00AA8282EFF7@mail.pubhealth.ku.dk>
Message-ID: <47FB554F.801@statistik.tu-dortmund.de>



volkmar.klatt at bnv-bamberg.de wrote:
> Full_Name: Volkmar Klatt
> Version: 2.6.2
> OS: linux
> Submission from: (NULL) (84.147.0.178)
> 
> 
> Hello,
> 
> the documentation article
> ?Quotes 
> from package:base could be improved by discussing
> the meaning of "\0" escape sequence.
> In R (currently used: R-2.6.2), a "\0" in a string will
> silently terminate that string, just as it would in C code.
> There is no warning about an unknown escape sequence.
> (cf. R FAQ 7.37)


So having read that, I do expect the behavior you write about below.

Best wishes,
Uwe




> # example:
> s <- "abc\0def"
> s
> # --> [1] "abc"
> nchar(s) 
> # --> [1] 3
> 
> The "\0" seems to be so fundamental, that it cannot be handled by
> any R function, am I right?
> E.g., the function escapeBS (package:Hmisc) does not correctly
> handle "\0" sequences, that is in contrast to what is stated in its 
> article ?escapeBS :
> "'escapeBS' will escape any backslash '\backslash' in a string.
> 
> # example:
> library(Hmisc)
> escapeBS("abc\0def")
> # -->[1] "abc"
> 
> Bye,
> Volkmar Klatt
> volkmar.klatt AT bnv-bamberg.de
> 
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel



[Rd] "\0" gives no warning "unknown escape sequence" (PR#11107)
Uwe Ligges