[Rd] Comments in the DESCRIPTION file

Hervé Pagès hpages at fhcrc.org
Fri Dec 7 00:41:41 CET 2012


Hi,

Wouldn't be hard to patch read.dcf() though.

FWIW here's the "comment aware" version of read.dcf() I've been using
for years:

   .removeCommentLines <- function(infile=stdin(), outfile=stdout())
   {
     if (is.character(infile)) {
         infile <- file(infile, "r")
         on.exit(close(infile))
     }
     if (is.character(outfile)) {
         outfile <- file(outfile, "w")
         on.exit({close(infile); close(outfile)})
     }
     while (TRUE) {
         lines <- readLines(infile, n=25000L)
         if (length(lines) == 0L)
             return()
         keep_it <- substr(lines, 1L, 1L) != "#"
         writeLines(lines[keep_it], outfile)
     }
   }

   read.dcf2 <- function(file, ...)
   {
     clean_file <- file.path(tempdir(), "clean.dcf")
     .removeCommentLines(file, clean_file)
     on.exit(file.remove(clean_file))
     read.dcf(clean_file, ...)
   }

Cheers,
H.

On 11/07/2012 01:53 AM, Duncan Murdoch wrote:
> On 12-11-07 4:26 AM, Christophe Genolini wrote:
>> Hi all,
>>
>> Is it possible to add comments in the DESCRIPTION file?
>
>
> The read.dcf function is used to read the DESCRIPTION file, and it
> doesn't support comments.  (The current Debian control format
> description does appear to support comments with leading # markers, but
> R's read.dcf function doesn't support these.)
>
> You could probably get away with something like
>
> #: this is a comment
>
> since unrecognized fields are ignored, but I think this fact is
> undocumented so I would say it's safer to assume that comments are not
> supported.
>
> Duncan Murdoch
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel

-- 
Hervé Pagès

Program in Computational Biology
Division of Public Health Sciences
Fred Hutchinson Cancer Research Center
1100 Fairview Ave. N, M1-B514
P.O. Box 19024
Seattle, WA 98109-1024

E-mail: hpages at fhcrc.org
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