curl_version_info(3)

NAME
curl_version_info - returns run-time libcurl version info

SYNOPSIS
#include <curl/curl.h>

curl_version_info_data *curl_version_info( CURLversion type);

DESCRIPTION
Returns a pointer to a filled in struct with information about various run-time features in libcurl. type 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 an 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;     /* number */
  const char *libz_version; /* human readable string */
  const char **protocols;   /* list of 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 */

} curl_version_info_data;

age describes what age of this struct this is. The number depends on how new libcurl you're using. 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_IPV6
        supports IPv6

    CURL_VERSION_KERBEROS4
        supports kerberos4 (when using FTP)

    CURL_VERSION_SSL
        supports SSL (HTTPS/FTPS)

    CURL_VERSION_LIBZ
        supports HTTP deflate using libz

    CURL_VERSION_NTLM
        supports HTTP NTLM (added in 7.10.6)

    CURL_VERSION_GSSNEGOTIATE
        supports HTTP GSS-Negotiate (added in 7.10.6)

    CURL_VERSION_DEBUG
        libcurl was built with extra debug capabilities built-in. This is mainly of interest for libcurl hackers. (added in 7.10.6)

    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_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_LARGEFILE
        libcurl was built with support for large files.

    CURL_VERSION_IDN
        libcurl was built with support for IDNA, domain names with international letters.
ssl_version is an ascii string for the OpenSSL version used. If libcurl has no SSL support, this is NULL.

ssl_version_num is the numerical OpenSSL version value as defined by the OpenSSL project. If libcurl has no SSL support, this is 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)