[Rd] Comments in the DESCRIPTION file

[Hervé Pagès]

On 12/06/2012 03:41 PM, Hervé Pagès wrote:
> 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")

mmh, would certainly be better to just use tempfile() here.

H.

>      .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

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