diff --git a/docs/quickstart_filters.md b/docs/quickstart_filters.md new file mode 100644 index 000000000..f26bad6fa --- /dev/null +++ b/docs/quickstart_filters.md @@ -0,0 +1,45 @@ +Appendix D.1. NetCDF-4 Filter QuickStart {#nc_filters_quickstart} +============================== + +> For full **Filters** documentation, see \ref filters. + +**The `libnetcdf.so` library cannot talk to plugin libraries directly. Instead, it requires an "interface" library, which acts as a go-between. The interface libraries are built by the netCDF libraries, when the underlying plugin libraries are detected during configure/build.** + +Building and Installing the Interface Libraries {#nc_filters_qs_building} +---------------------------------- + +### Configuring + +When configuring netcdf via either the `configure` script or via `cmake`, you'll need to specify the location to install the interface libraries, as follows: + +* configure: `--enable-plugins` `--with-plugin-dir=$NCPLUGIN_DIR` +* cmake: `-DPLUGIN_INSTALL_DIR=$NCPLUGIN_DIR` + +where `$NCPLUGIN_DIR` is the path to the user-defined directory, e.g. `/usr/local/nc-plugins` + +After compiling and installing `libnetcdf`, the interface libraries for those filters detected will be installed in the user-specified `NCPLUGIN_DIR`. + +> `nc-config --plugindir` will return the location where plugins were installed. + +Using the Interface Libraries at Run-time {#nc_filters_qs_runtime} +--------------------------------- + +For historical reasons, `libnetcdf` uses the environmental variable `HDF5_PLUGIN_PATH` to locate the interface libraries at run-time. This location should be set to the `$NCPLUGIN_DIR` specified when building and installing `libnetcdf`. + + +Example Workflow (blosc) {#nc_filters_qs_workflow_example} +-------------------------------------------------- + +From scratch, the steps to get this to work are as follows, and assumes `libhdf5` was installed. + +1. Install the filter library, and the associate development headers. +2. Configure netCDF with `--enable-plugins` and `--with-plugin-dir=$HOME/netcdf-plugins` +3. Ensure `blosc` is specified in the generated `libnetcdf.settings` file. +4. Run make, make install. + +Once built and installed, set the environmental variable `HDF5_PLUGIN_PATH=$HOME/netcdf-plugins`. + +The reason this works is because: + +1. NetCDF builds the interface library. +2. `ncdump` knows where to find the interface library because `HDF5_PLUGIN_PATH` is set.