Hi Steve,
Compiling v5.0.10, I have noticed that the default
{virtuoso}/var/lib/db/virtuoso.ini loads 3 plugins (listed below) that do
not seem to be built, despite being listed as defaults in the configure
options.
Load4 plain, im ImageMagick plugin used by ODS-Gallery
Load5 plain, wbxml2 WbXML plugin used by the SyncML package
Load6 plain, hslookup Required for some Sponger Cartridge operations
Described
here<http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/VirtConfigScale#Configuration%20Options>
These plugins provide optional extra features to certain VAD packages,
but are not needed by the main engine. Currently we have not yet made
the default virtuoso.ini generate these lines only when the actual
plugins are generated, but we may fix this sometime.
Virtuoso will give a warning at startup, but that can be safely ignored.
The VAD package will check if the plugins it needs are not present and
tell you to install the missing plugin.
The configure script checks for the existance of the underlying
libraries for these plugins and will activate these plugins if these
libraries exists as a system supplied library.
If a library does not exist in a system directory an optional DIR
argument can be provided to tell configure where to actually look for
this library.
If the configure checks fail it will disable the plugin.
Alternatively you can disable the building of a certain plugin manually
should you so desire.
So giving the Image Magick library as an example which is needed to
build the im.so plugin that is used in the ODS-Gallery app for scaling
images:
--enable-imagemagick(=DIR) enable the ImageMagick plugin (default)
--disable-imagemagick disable the ImageMagick plugin
This means that if you do nothing, configure will check if there is a
working ImageMagick library in the system directory, if so it will
enable the im.so plugin building/installing. Same happens when you
explicitly use:
--enable-imagemagick
To explicitly use a particular local build of Image Magick you can use:
--enable-imagemagick=/usr/local/ImageMagick
or if you have an Image Magick library installed somewhere, but you do
not want to build the plugin, you use:
--disable-imagemagick
This is true for all plugins and other libraries (like openssl) that VOS
can use without the need for a special build.
For the hosting options, eg PHP hosting, VOS cannot use a system
standard PHP installation, since most installations do not by default
configure the PHP code with the right flags for zend threading support
etc. In those cases you will find that configure has a default of
--disable, and the user has to explicitly tell configure where to find
the specially build version of the library you want to use.
<http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/VirtConfigScale#Configuration%20Options>I
was expecting the samples location ({virtuoso-source}/binsrc/samples) to
build and output them to {virtuoso}/lib/virtuoso/hosting/ with the rest of
the plugins. Am I missing something here?
Well you can check your config.log output to see why configure disabled
the building of these plugins.
Also, does the ImageMagick plugin rely on or replace having separately built
ImageMagick libraries?
The im.so plugin only provide an interface to the ImageMagick library
and is therefor linked with the ImageMagick libraries. In case of
ImageMagick you should be able to use the system supplied version if
available for your OS.
Hope this answers your questions.
Patrick
