Is it possible to install pandoc on windows using the R command?

Question

I would like to download and install pandoc on a Windows 7 machine by running a command in R. Is this possible?

(I know that I can do it manually, but when I show it to students - the more steps I can organize in the R-code block), the better)

Answer 1

How to simply download the latest installer and start with R:

• a) Determine the latest version of Pandoc and grab the URL using the XML package:

   library(XML) page <- readLines('http://code.google.com/p/pandoc/downloads/list', warn = FALSE) pagetree <- htmlTreeParse(page, error=function(...){}, useInternalNodes = TRUE, encoding='UTF-8') url <- xpathSApply(pagetree, '//tr[2]//td[1]//a ', xmlAttrs)[1] url <- paste('http', url, sep = ':') 

  b) Or apply some regexp magic thanks to @ G.Grothendieck instead (no XML package needed this way):

   page <- readLines('http://code.google.com/p/pandoc/downloads/list', warn = FALSE) pat <- "//pandoc.googlecode.com/files/pandoc-[0-9.]+-setup.exe" line <- grep(pat, page, value = TRUE); m <- regexpr(pat, line) url <- paste('http', regmatches(line, m), sep = ':') 

  c) Or just check the latest version manually if you want:

   url <- 'http://pandoc.googlecode.com/files/pandoc-1.10.1-setup.exe' 

• Download the file as binary :

   t <- tempfile(fileext = '.exe') download.file(url, t, mode = 'wb') 

• And just run it from R:

   system(t) 

• Delete the unnecessary file after installation:

   unlink(t) 

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PS: sorry, only tested on Windows XP