[Rd] directing print.packageInfo to a file

Kurt Hornik Kurt.Hornik at wu-wien.ac.at
Mon Aug 2 11:41:03 CEST 2004

>>>>> Gabor Grothendieck writes:

> I already suggested using the pager as a workaround
> in the original thread although your pager workaround
> has the advantage of being 100% in R while mine used
> a batch file which defined a new pager.
> Note that R already supports
>    options(pager = "console")
> but if you do this then it seems that capture.output
> still won't capture it.  Thus one alternative solution
> would be to get capture.output to work with 
> pager = "console" and modify print.packageInfo to
> take a pager= argument which it would pass down to file.show.
> (file.show already has a pager argument.)
> Then one could write:
>   capture.output( print.packageInfo(help(package = chron), 
>             pager = "console"), file = "myfile.txt")
> That gets it down to one line although it still seems
> unnecessarily indirect when one could just write:
>   print.packageInfo(help(package = chron), file = "myfile.txt")
> if print.packageInfo just had a file= argument.
> Furthermore, print.packageInfo ALREADY creates the file as a 
> temporary file to hand over to file.show so its not much of
> a stretch to give the user access to what it is already 
> creating anyway.

The point about the proferred solution is that it works generally when
is is desired to capture output that is "printed" via file.show().  If
we start adding extra arguments to print.packageIQR (which is documented
to be internal, btw), we would need to do the same for print.libraryIQR
and print.hsearch and ..., i.e. for all print() methods which in fact
display something using file.show() as a "side effect".  That seems
suboptimal to me, when one can wrap the above in a very simple and
generally applicable function (and just calling the print() generic
rather than some method, btw).


More information about the R-devel mailing list