reproduce what rmarkdown is doing

[KevCaz]

I think some function that are not exported could be very useful, for instance:

# get the path to the pandoc binary
pandoc <- function() {

  find_pandoc()
  file.path(.pandoc$dir, "pandoc")
}


# get the path to the pandoc-citeproc binary
pandoc_citeproc <- function() {

  find_pandoc()
  citeproc_path = file.path(.pandoc$dir, "pandoc-citeproc")
  if (file.exists(citeproc_path))
    citeproc_path
  else
    "pandoc-citeproc"
}


# quote args if they need it
quoted <- function(args) {

  # some characters are legal in filenames but without quoting are likely to be
  # interpreted by the shell (e.g. redirection, wildcard expansion, etc.) --
  # wrap arguments containing these characters in quotes.
  shell_chars <- grepl(.shell_chars_regex, args)
  args[shell_chars] <- shQuote(args[shell_chars])
  args
}