Re: [Rd] pattern in history

From: Prof Brian Ripley <ripley_at_stats.ox.ac.uk>
Date: Tue 11 Apr 2006 - 12:12:32 GMT

That's an interesting suggestion, but

  1. it is not a good idea to change the order of arguments in a function.
  2. is the 'unique' argument useful? I cannot see it being used if there is no pattern search, nor I do see the merit in showing repeated lines if I have subselected.
  3. like ls(), testing if 'pattern' were missing or NULL would be a better idea.

On Tue, 11 Apr 2006, Romain Francois wrote:

> Hi,
>
> Sometimes I need to consult the history of commands that are matching a
> regex, so I modified the utils::history function for that purpose. I
> found it useful.
>
> I append the code ( I only added the two lines with #**)
>
> Romain.
>
>
> history2 <-
> function (pattern="", max.show = 25, reverse = FALSE, unique =
> pattern!="", ...)
> {
> file1 <- tempfile("Rrawhist")
> savehistory(file1)
> rawhist <- scan(file1, what = "", quiet = TRUE, sep = "\n")
> rawhist <- rawhist[grep(pattern, rawhist, ...)] #**
> if(unique) rawhist <- unique(rawhist) #**
> unlink(file1)
> nlines <- length(rawhist)
>
> inds <- max(1, nlines - max.show):nlines
> if (reverse)
> inds <- rev(inds)
> file2 <- tempfile("hist")
> write(rawhist[inds], file2)
> file.show(file2, title = "R History", delete.file = TRUE)
> }
>
>
>

-- 
Brian D. Ripley,                  ripley@stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

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Received on Tue Apr 11 23:55:20 2006

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