downloads a gist to a file

download_gist.R

# downloads a gist
# usage: download_gist("4539629", "4539629.R")
#
# see also: source_gist {devtools}
download_gist <- function (entry, destfile, ...) 
{
  if (is.numeric(entry) || grepl("^[[:digit:]]+$", entry)) {
    entry <- paste("https://raw.github.com/gist/", entry, 
                   sep = "")
  }
  else if (grepl("((^https://)|^)gist.github.com/[[:digit:]]+$", 
                 entry)) {
    entry <- paste("https://raw.github.com/gist/", regmatches(entry, 
                                                              regexpr("[[:digit:]]+$", entry)), sep = "")
  }
  download.file(entry, destfile, ...)
}