libcurlVersion: Report Version of libcurl
In robertzk/monadicbase: The R Base Package

Report version of libcurl in use.

1	libcurlVersion()

A character string, with value the libcurl version in use or "" if none is. If libcurl is available, has attributes

`ssl_version`	A character string naming the SSL implementation and version, possibly `"none"`. It is intended for the version of OpenSSL used, but not all implementations of `libcurl` use OpenSSL — for example OS X reports `"SecureTranspart"`, its wrapper for SSL/TLS.
`libssh_version`	A character string naming the `libssh` version, which may or may not be available (it is used for e.g. `scp` and `sftp` protocols). Where present, something like `"libssh2/1.5.0"`.
`protocols`	A character vector of the names of supported protocols, also known as ‘schemes’ when part of a URL.

extSoftVersion for versions of other third-party software.

curlGetHeaders, download.file and url for functions which (optionally) use libcurl.

http://curl.haxx.se/docs/sslcerts.html and http://curl.haxx.se/docs/ssl-compared.html for more details on SSL versions. Normally libcurl used with R uses SecureTransport on OS X, OpenSSL on Windows and GnuTLS, NSS or OpenSSL on Unix-alikes. (At the time of writing Debian-based Linuxen use GnuTLS, RedHat-based ones use NSS.)