gnurl_version_info(3)

📦 version 7.72.0, in nixos 26.05, nixpkgs unstable

🌸 NAME 🌸

okay so bestie, this is the gnurl_version_info(3) page from the libgnurl Manual, and it's literally here to explain curl_version_info — aka returns run-time libcurl version info ✨. It's giving “tell me everything about the libcurl I'm running right now” energy, and honestly? iconic.

✨ SYNOPSIS ✨

#include <gnurl/curl.h>

curl_version_info_data *curl_version_info( CURLversion age);

🎀 DESCRIPTION 🎀

So this function returns a pointer to a filled-in static struct with info about all the various features in the running version of libcurl 🫶.

You set age to the version of this functionality at the time you write your program. That way, libcurl always returns a proper struct that your program understands, while future programs might get a different struct. CURLVERSION_NOW is 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, because dynamic/DLL libraries can be changed independent of applications 👑.

The curl_version_info_data struct looks like this, no edits, periodt:

typedef struct {
  CURLversion age;          /* see description below */

  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 CURLVERSION_SECOND or higher, the members below exist */
  const char *ares;         /* human readable string */
  int ares_num;             /* number */

  /* when 'age' is CURLVERSION_THIRD or higher, the members below exist */
  const char *libidn;       /* human readable string */

  /* when 'age' is CURLVERSION_FOURTH or higher (>= 7.16.1), the members
     below exist */
  int iconv_ver_num;       /* '_libiconv_version' if iconv support enabled */

  const char *libssh_version; /* human readable string */

  /* when 'age' is CURLVERSION_FIFTH or higher (>= 7.57.0), the members
     below 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 higher (>= 7.66.0), the members
     below 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 */

  /* when 'age' is CURLVERSION_SEVENTH or higher (>= 7.70.0), the members
     below exist */
  const char *cainfo;          /* the built-in default CURLOPT_CAINFO, might
                                  be NULL */
  const char *capath;          /* the built-in default CURLOPT_CAPATH, might
                                  be NULL */
  /* when 'age' is CURLVERSION_EIGHTH or higher (>= 7.71.0), the members
     below exist */
  unsigned int zstd_ver_num; /* Numeric Zstd version
                                  (MAJOR << 24) | (MINOR << 12) | PATCH */
  const char *zstd_version; /* human readable string. */
} 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, because 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 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_ZSTD — supports HTTP zstd content encoding using zstd library (Added in 7.72.0).
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). Legacy bit. Deprecated since 7.33.0. like bestie, it's literally deprecated, don't build new vibes on it.
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_UNICODE — libcurl was built with Unicode support on Windows. This makes non-ASCII characters work in filenames and options passed to libcurl. (Added in 7.72.0)
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. iykyk 👑

🫶 RETURN VALUE 🫶

A pointer to a curl_version_info_data struct. simple as that, bestie 💖

🔥 SEE ALSO 🔥

curl_version(3)

mwah 💋 — this little page is brought to you by libcurl 7.40.0, dated 2 Nov 2014, and that's the footer, periodt 🌈

📦 where this page comes from

nixos 26.05: libgnurl 7.72.0
nixpkgs unstable: libgnurl 7.72.0
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on 2026-11-04: a language model's rewrite of the original, under its terms