Report version of
libcurl in use.
A character string, with value the
libcurl version in use or
"" if none is. If
libcurl is available, has attributes
A character string naming the SSL/TLS implementation
and version, possibly
"none". It is intended for the version
of OpenSSL used, but not all implementations of
OpenSSL --- for example macOS reports
wrapper for SSL/TLS.
A character string naming the
which may or may not be available (it is used for
sftp protocols). Where present,
A character vector of the names of supported protocols, also known as ‘schemes’ when part of a URL.
In late 2017 a
libcurl installation was seen divided into two
libcurl-feature, and the first
had been updated but not the second. As the compiled function
recording the version was in the latter, the version reported by
libcurlVersion was misleading.
extSoftVersion for versions of other third-party
http://curl.haxx.se/docs/ssl-compared.html for more details on
SSL versions (the current standard being known as TLS). Normally
libcurl used with R uses SecureTransport on macOS, OpenSSL on
Windows and GnuTLS, NSS or OpenSSL on Unix-alikes. (At the time of
writing Debian-based Linuxen use GnuTLS and RedHat-based ones use NSS,
but it has been announced that Fedora 27 will switch to OpenSSL.)