Manpage of curl_version_info

curl_version_info

Section: libcurl Manual (3)
Updated: 19 Sep 2003
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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;          /* 0 - this kind of struct */
  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 */
  char *libz_version;       /* human readable string */
  const char *protocols[];  /* list of protocols */
} curl_version_info_data;

age describes what kind of struct this is. It is always 0 now. In a future libcurl, if this struct changes, this age counter may be increased, and then the struct for number 1 will look different (except for this first struct field).

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)

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.