.\" **************************************************************************
.\" *                                  _   _ ____  _
.\" *  Project                     ___| | | |  _ \| |
.\" *                             / __| | | | |_) | |
.\" *                            | (__| |_| |  _ <| |___
.\" *                             \___|\___/|_| \_\_____|
.\" *
.\" * Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
.\" *
.\" * This software is licensed as described in the file COPYING, which
.\" * you should have received as part of this distribution. The terms
.\" * are also available at https://curl.se/docs/copyright.html.
.\" *
.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
.\" * copies of the Software, and permit persons to whom the Software is
.\" * furnished to do so, under the terms of the COPYING file.
.\" *
.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
.\" * KIND, either express or implied.
.\" *
.\" **************************************************************************
.\"
.TH curl_version_info 3 "April 03, 2021" "libcurl 7.78.0" "libcurl Manual"

.SH NAME
curl_version_info - returns run-time libcurl version info
.SH SYNOPSIS
.B #include <curl/curl.h>
.sp
.BI "curl_version_info_data *curl_version_info( CURLversion "age ");"
.ad
.SH DESCRIPTION
Returns a pointer to a filled in static struct with information about various
features in the running version of libcurl. \fIage\fP 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. \fBCURLVERSION_NOW\fP 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

.nf
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. */
  /* when 'age' is CURLVERSION_NINTH or higher (>= 7.75.0), the members
     below exist */
  const char *hyper_version; /* human readable string. */
  /* when 'age' is CURLVERSION_TENTH or higher (>= 7.77.0), the members
     below exist */
  const char *gsasl_version; /* human readable string. */
} curl_version_info_data;
.fi

\fIage\fP 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.

\fIversion\fP is just an ascii string for the libcurl version.

\fIversion_num\fP 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.

\fIhost\fP 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.

\fIfeatures\fP can have none, one or more bits set, and the currently defined
bits are:
.RS
.IP CURL_VERSION_ALTSVC
HTTP Alt-Svc parsing and the associated options (Added in 7.64.1)
.IP 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)
.IP CURL_VERSION_BROTLI
supports HTTP Brotli content encoding using libbrotlidec (Added in 7.57.0)
.IP CURL_VERSION_ZSTD
supports HTTP zstd content encoding using zstd library (Added in 7.72.0)
.IP CURL_VERSION_CONV
libcurl was built with support for character conversions, as provided by the
CURLOPT_CONV_* callbacks. (Added in 7.15.4)
.IP CURL_VERSION_CURLDEBUG
libcurl was built with memory tracking debug capabilities. This is mainly of
interest for libcurl hackers. (added in 7.19.6)
.IP CURL_VERSION_DEBUG
libcurl was built with debug capabilities (added in 7.10.6)
.IP CURL_VERSION_GSASL
libcurl was built with libgsasl and thus with some extra SCRAM-SHA
authentication methods. (added in 7.76.0)
.IP 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)
.IP CURL_VERSION_GSSNEGOTIATE
supports HTTP GSS-Negotiate (added in 7.10.6)
.IP CURL_VERSION_HSTS
libcurl was built with support for HSTS (HTTP Strict Transport Security)
(Added in 7.74.0)
.IP CURL_VERSION_HTTPS_PROXY
libcurl was built with support for HTTPS-proxy.
(Added in 7.52.0)
.IP CURL_VERSION_HTTP2
libcurl was built with support for HTTP2.
(Added in 7.33.0)
.IP CURL_VERSION_HTTP3
HTTP/3 and QUIC support are built-in (Added in 7.66.0)
.IP CURL_VERSION_IDN
libcurl was built with support for IDNA, domain names with international
letters. (Added in 7.12.0)
.IP CURL_VERSION_IPV6
supports IPv6
.IP CURL_VERSION_KERBEROS4
supports Kerberos V4 (when using FTP). Legacy bit. Deprecated since 7.33.0.
.IP CURL_VERSION_KERBEROS5
supports Kerberos V5 authentication for FTP, IMAP, POP3, SMTP and SOCKSv5 proxy
(Added in 7.40.0)
.IP CURL_VERSION_LARGEFILE
libcurl was built with support for large files. (Added in 7.11.1)
.IP 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)
.IP CURL_VERSION_LIBZ
supports HTTP deflate using libz (Added in 7.10)
.IP CURL_VERSION_MULTI_SSL
libcurl was built with multiple SSL backends. For details, see
\fIcurl_global_sslset(3)\fP.
(Added in 7.56.0)
.IP CURL_VERSION_NTLM
supports HTTP NTLM (added in 7.10.6)
.IP CURL_VERSION_NTLM_WB
libcurl was built with support for NTLM delegation to a winbind helper.
(Added in 7.22.0)
.IP 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)
.IP 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)
.IP CURL_VERSION_SSL
supports SSL (HTTPS/FTPS) (Added in 7.10)
.IP 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)
.IP CURL_VERSION_TLSAUTH_SRP
libcurl was built with support for TLS-SRP (in one or more of the built-in TLS
backends). (Added in 7.21.4)
.IP CURL_VERSION_UNIX_SOCKETS
libcurl was built with support for Unix domain sockets.
(Added in 7.40.0)
.RE
\fIssl_version\fP 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".

\fIssl_version_num\fP is always 0.

\fIlibz_version\fP is an ASCII string (there is no numerical version). If
libcurl has no libz support, this is NULL.

\fIprotocols\fP 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.
.SH RETURN VALUE
A pointer to a curl_version_info_data struct.
.SH "SEE ALSO"
\fIcurl_version(3)\fP