=head1 NAME

nbd_get_version_extra - return the extra version of the library

=head1 SYNOPSIS

 #include <libnbd.h>

 const char * nbd_get_version_extra (
                struct nbd_handle *h
              );

=head1 DESCRIPTION

Return the extra version of libnbd.  This is a freeform string
which is set at package build time using:

 ./configure --with-extra="..."

and it intended to be used by downstream packagers (eg. Linux distributions)
to convey extra version information, such as the precise version of
the libnbd RPM, C<.deb> etc.

The string may be C<"">, indicating that no extra version information
is available, or that this is an upstream build of libnbd.

=head1 RETURN VALUE

This call returns a statically allocated string, valid for the
lifetime of the process or until libnbd is unloaded by
L<dlclose(3)>.  You B<must not> try to free the string.

=head1 ERRORS

This function does not fail.

The following parameters must not be NULL: C<h>.
For more information see L<libnbd(3)/Non-NULL parameters>.

=head1 VERSION

This function first appeared in libnbd 1.24.

If you need to test if this function is available at compile time
check if the following macro is defined:

 #define LIBNBD_HAVE_NBD_GET_VERSION_EXTRA 1

=head1 SEE ALSO

L<nbd_create(3)>,
L<nbd_get_package_name(3)>,
L<nbd_get_version_extra(3)>,
L<libnbd(3)>.

=head1 AUTHORS

Eric Blake

Richard W.M. Jones

=head1 COPYRIGHT

Copyright Red Hat
