Libcurl implementation of C_download (the "internal" download method)
with added support for https, ftps, gzip, etc. Default behavior is identical
to download.file, but request can be fully configured by passing
a custom handle.
A character string naming the URL of a resource to be downloaded.
A character string with the name where the downloaded file
is saved. Tilde-expansion is performed.
If TRUE, suppress status messages (if any), and the
A character string specifying the mode with which to write the file.
Useful values are "w", "wb" (binary), "a" (append)
a curl handle object
The main difference between curl_download and curl_fetch_disk
is that curl_download checks the http status code before starting the
download, and raises an error when status is non-successful. The behavior of
curl_fetch_disk on the other hand is to proceed as normal and write
the error page to disk in case of a non success response.
For a more advanced download interface which supports concurrent requests and
resuming large files, have a look at the multi_download function.