libcurlVersion: Report Version of libcurl

Description Usage Value Warning See Also Examples


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 libcurl use OpenSSL — for example macOS reports "SecureTranspart", its wrapper for SSL/TLS.


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".


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 libraries, libcurl and 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.

See Also

extSoftVersion for versions of other third-party software.

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