— Function: const char * gpgme_check_version (const char *required_version)

The function gpgme_check_version has three purposes. It can be used to retrieve the version number of the library. In addition it can verify that the version number is higher than a certain required version number. In either case, the function initializes some sub-systems, and for this reason alone it must be invoked early in your program, before you make use of the other functions in GPGME.

As a side effect for W32 based systems, the socket layer will get initialized.

If required_version is NULL, the function returns a pointer to a statically allocated string containing the version number of the library.

If required_version is not NULL, it should point to a string containing a version number, and the function checks that the version of the library is at least as high as the version number provided. In this case, the function returns a pointer to a statically allocated string containing the version number of the library. If REQUIRED_VERSION is not a valid version number, or if the version requirement is not met, the function returns NULL.

If you use a version of a library that is backwards compatible with older releases, but contains additional interfaces which your program uses, this function provides a run-time check if the necessary features are provided by the installed version of the library.

     #include <locale.h>
     #include <gpgme.h>
     
     void
     init_program (void)
     {
       /* Initialize the locale environment.  */
       setlocale (LC_ALL, "");
       gpgme_check_version (NULL);
       gpgme_set_locale (NULL, LC_CTYPE, setlocale (LC_CTYPE, NULL));
     #ifdef LC_MESSAGES
       gpgme_set_locale (NULL, LC_MESSAGES, setlocale (LC_MESSAGES, NULL));
     #endif
     }