The R4.2.0 update made libcurl the default for the download.file function (and removed the wininet method for some types of url schemes). The same is true for the download.packages function.
My work uses a proxy.pac file in conjunction with NTLM authentication for the proxy. As a result, the changes made to the download.file make it not work with this type of proxy unless you specifically choose the wininet option (but this only works for some url schemes).
One of the consequences of this confluence of configurations is that users have to manually change the default package manager to be an internal mirror of CRAN to use the package installer at all in RStudio.
I've managed to use the curl library to be able to download files through the proxy:
base_directory <- "<save_path>"
handle <- curl::new_handle()
url <- "url_page_to_download"
handle_opts <- list(
proxy = curl::ie_get_proxy_for_url(url), # figures out the relevant proxy string for the url (or url stub you are using)
proxyauth = 8, # value of CURLAUTH_NTLM from curl_symbols()
proxyuserpwd = ":" # specifically set to “:” to force windows to do the negotiation. This string is the same as sending no username and password
)
handle_setopt(handle,.list=handle_opts)
data_file_location <- paste0(base_directory,"state.txt")
curl_download(url, destfile=data_file_location, quiet=FALSE, handle=handle)
I would like to find a way to do this that uses the libcurl method of the download.packages and download.file functions, which involves setting some environment variables (from what I can tell), but I can't find the set of parameters to place in the environment variables to get it to work.
How can I replicate this with the built in functions?
