focal (3) curl_version_info.3.gz
NAME
curl_version_info - returns run-time libcurl version info
SYNOPSIS
#include <curl/curl.h>
curl_version_info_data *curl_version_info( CURLversion age);
DESCRIPTION
Returns a pointer to a filled in static struct with information about various features in the running
version of libcurl. age should be set to the version of this functionality by the time you write your
program. This way, libcurl will always return a proper struct that your program understands, while
programs in the future might get a different struct. CURLVERSION_NOW will be the most recent one for the
library you have installed:
data = curl_version_info(CURLVERSION_NOW);
Applications should use this information to judge if things are possible to do or not, instead of using
compile-time checks, as dynamic/DLL libraries can be changed independent of applications.
The curl_version_info_data struct looks like this
typedef struct {
CURLversion age; /* see description below */
/* when 'age' is 0 or higher, the members below also exist: */
const char *version; /* human readable string */
unsigned int version_num; /* numeric representation */
const char *host; /* human readable string */
int features; /* bitmask, see below */
char *ssl_version; /* human readable string */
long ssl_version_num; /* not used, always zero */
const char *libz_version; /* human readable string */
const char * const *protocols; /* protocols */
/* when 'age' is 1 or higher, the members below also exist: */
const char *ares; /* human readable string */
int ares_num; /* number */
/* when 'age' is 2 or higher, the member below also exists: */
const char *libidn; /* human readable string */
/* when 'age' is 3 or higher (7.16.1 or later), the members below also
exist */
int iconv_ver_num; /* '_libiconv_version' if iconv support enabled */
const char *libssh_version; /* human readable string */
/* when 'age' is 4 or higher (7.57.0 or later), the members below also
exist */
unsigned int brotli_ver_num; /* Numeric Brotli version
(MAJOR << 24) | (MINOR << 12) | PATCH */
const char *brotli_version; /* human readable string. */
/* when 'age is CURLVERSION_SIXTH or alter (7.66.0 or later), these fields
also exist */
unsigned int nghttp2_ver_num; /* Numeric nghttp2 version
(MAJOR << 16) | (MINOR << 8) | PATCH */
const char *nghttp2_version; /* human readable string. */
const char *quic_version; /* human readable quic (+ HTTP/3) library +
version or NULL */
} curl_version_info_data;
age describes what the age of this struct is. The number depends on how new the libcurl you're using is.
You are however guaranteed to get a struct that you have a matching struct for in the header, as you tell
libcurl your "age" with the input argument.
version is just an ascii string for the libcurl version.
version_num is a 24 bit number created like this: <8 bits major number> | <8 bits minor number> | <8 bits
patch number>. Version 7.9.8 is therefore returned as 0x070908.
host is an ascii string showing what host information that this libcurl was built for. As discovered by a
configure script or set by the build environment.
features can have none, one or more bits set, and the currently defined bits are:
CURL_VERSION_ALTSVC
HTTP Alt-Svc parsing and the associated options (Added in 7.64.1)
CURL_VERSION_ASYNCHDNS
libcurl was built with support for asynchronous name lookups, which allows more exact
timeouts (even on Windows) and less blocking when using the multi interface. (added in
7.10.7)
CURL_VERSION_BROTLI
supports HTTP Brotli content encoding using libbrotlidec (Added in 7.57.0)
CURL_VERSION_CONV
libcurl was built with support for character conversions, as provided by the CURLOPT_CONV_*
callbacks. (Added in 7.15.4)
CURL_VERSION_CURLDEBUG
libcurl was built with memory tracking debug capabilities. This is mainly of interest for
libcurl hackers. (added in 7.19.6)
CURL_VERSION_DEBUG
libcurl was built with debug capabilities (added in 7.10.6)
CURL_VERSION_GSSAPI
libcurl was built with support for GSS-API. This makes libcurl use provided functions for
Kerberos and SPNEGO authentication. It also allows libcurl to use the current user
credentials without the app having to pass them on. (Added in 7.38.0)
CURL_VERSION_GSSNEGOTIATE
supports HTTP GSS-Negotiate (added in 7.10.6)
CURL_VERSION_HTTPS_PROXY
libcurl was built with support for HTTPS-proxy. (Added in 7.52.0)
CURL_VERSION_HTTP2
libcurl was built with support for HTTP2. (Added in 7.33.0)
CURL_VERSION_HTTP3
HTTP/3 and QUIC support are built-in (Added in 7.66.0)
CURL_VERSION_IDN
libcurl was built with support for IDNA, domain names with international letters. (Added in
7.12.0)
CURL_VERSION_IPV6
supports IPv6
CURL_VERSION_KERBEROS4
supports Kerberos V4 (when using FTP)
CURL_VERSION_KERBEROS5
supports Kerberos V5 authentication for FTP, IMAP, POP3, SMTP and SOCKSv5 proxy (Added in
7.40.0)
CURL_VERSION_LARGEFILE
libcurl was built with support for large files. (Added in 7.11.1)
CURL_VERSION_LIBZ
supports HTTP deflate using libz (Added in 7.10)
CURL_VERSION_MULTI_SSL
libcurl was built with multiple SSL backends. For details, see curl_global_sslset(3).
(Added in 7.56.0)
CURL_VERSION_NTLM
supports HTTP NTLM (added in 7.10.6)
CURL_VERSION_NTLM_WB
libcurl was built with support for NTLM delegation to a winbind helper. (Added in 7.22.0)
CURL_VERSION_PSL
libcurl was built with support for Mozilla's Public Suffix List. This makes libcurl ignore
cookies with a domain that's on the list. (Added in 7.47.0)
CURL_VERSION_SPNEGO
libcurl was built with support for SPNEGO authentication (Simple and Protected GSS-API
Negotiation Mechanism, defined in RFC 2478.) (added in 7.10.8)
CURL_VERSION_SSL
supports SSL (HTTPS/FTPS) (Added in 7.10)
CURL_VERSION_SSPI
libcurl was built with support for SSPI. This is only available on Windows and makes
libcurl use Windows-provided functions for Kerberos, NTLM, SPNEGO and Digest
authentication. It also allows libcurl to use the current user credentials without the app
having to pass them on. (Added in 7.13.2)
CURL_VERSION_TLSAUTH_SRP
libcurl was built with support for TLS-SRP. (Added in 7.21.4)
CURL_VERSION_UNIX_SOCKETS
libcurl was built with support for Unix domain sockets. (Added in 7.40.0)
ssl_version is an ASCII string for the TLS library name + version used. If libcurl has no SSL support,
this is NULL. For example "Schannel", "SecureTransport" or "OpenSSL/1.1.0g".
ssl_version_num is always 0.
libz_version is an ASCII string (there is no numerical version). If libcurl has no libz support, this is
NULL.
protocols is a pointer to an array of char * pointers, containing the names protocols that libcurl
supports (using lowercase letters). The protocol names are the same as would be used in URLs. The array
is terminated by a NULL entry.
RETURN VALUE
A pointer to a curl_version_info_data struct.
SEE ALSO
curl_version(3)