GRIB-382: grib_get_data also for C and Python: Exposed the C function and added C example

examples/C/Makefile.am

@@ -2,11 +2,11 @@
 AM_CFLAGS =  @WARN_PEDANTIC@ @WERROR@
 
 TESTS = iterator.sh get.sh print_data.sh set.sh keys_iterator.sh multi.sh multi_write.sh \
-	precision.sh list.sh large_grib1.sh
+	precision.sh list.sh large_grib1.sh get_data.sh
 
 noinst_PROGRAMS       = nearest set_bitmap iterator get print_data set set_missing keys_iterator \
 			set_data mars_param values_check box multi multi2 multi_write precision \
-			set_pv list sections_copy large_grib1
+			set_pv list sections_copy large_grib1 get_data
 bin_PROGRAMS          = points
 
 box_SOURCES           = box.c
@@ -29,6 +29,7 @@ points_SOURCES        = points.c
 list_SOURCES          = list.c
 sections_copy_SOURCES = sections_copy.c
 large_grib1_SOURCES   = large_grib1.c
+get_data_SOURCES      = get_data.c
 
 INCLUDES =  -I$(top_builddir)/src
 

src/grib_api.h

@@ -580,6 +580,19 @@ int grib_get_message_copy(grib_handle* h ,  void* message,size_t *message_length
 */
 grib_iterator*      grib_iterator_new      (grib_handle*   h, unsigned long flags,int* error);
 
+/**
+* Get latitude/longitude and data values.
+* The Latitudes, longitudes and values arrays must be properly allocated by the caller.
+* Their required dimension can be obtained by getting the value of the integer key "numberOfPoints".
+*
+* @param h           : handle from which geography and data values are taken
+* @param lats        : returned array of latitudes
+* @param lons        : returned array of longitudes
+* @param values      : returned array of data values
+* @return            0 if OK, integer value on error
+*/
+int grib_get_data(grib_handle *h, double *lats, double *lons, double *values, size_t *size);
+
 /**
 * Get the next value from an iterator.
 *