Separated headers; CRLF handling; Win .onLoad()

Needed to fix CRLG again. GRIB API functions that are made public in
this package have been split out into their own header. Added onLoad
function for Windows to handle GRIB_DEFINITION_PATH

.Rbuildignore

@@ -3,3 +3,4 @@
 ^configure\.ac$
 ^README\.md$
 ^\.DS_Store$
+^\.Rhistory$

R/grib_open.R

@@ -25,8 +25,14 @@
 
 grib_open <- function(file) {
 
-  # test to make sure file is actuall GRIB format
-  if (.Call("gribr_grib_test", path.expand(file))) {
+  # does it exist and is it a file
+  normFile <- normalizePath(file, mustWork = FALSE)
+  if (!file_test("-f", normFile)) {
+    stop("%s is not a valid file", normFile)
+  }
+
+  # test to make sure file is actually in GRIB format
+  if (.Call("gribr_grib_test", file)) {
     stop("File is not GRIB format (0 messages found)")
   }
 

R/zzz.R

@@ -0,0 +1,7 @@
+.onLoad <- function(library, package) {
+	if(.Platform$OS.type == "windows") {
+		if (Sys.getenv("GRIB_DEFINITION_PATH") == "") {
+			Sys.setenv(GRIB_DEFINITION_PATH = "")
+		}
+	}
+}

src/grib_api_extra.h

@@ -0,0 +1,5 @@
+/* This header contains functions/structs in the GRIB API that have not been
+   made public via the main header but are used by gribr */
+
+void grib_index_rewind(grib_index* index);
+char *grib_context_full_defs_path(grib_context* c, const char* basename);

src/grib_open.c

@@ -2,12 +2,27 @@
 #include <Rinternals.h>
 
 #include "gribr.h"
+#include "grib_api_extra.h"
 
 SEXP gribr_grib_open(SEXP gribr_fileName) {
 
   const char *p_fileName = NULL;
   SEXP gribr_fileHandle;
   FILE *input = NULL;
+  grib_context *c = NULL;
+  char *def_path = NULL;
+  const char *basename = "boot.def";
+
+  /* This important step makes sure that the GRIB
+  definition files for the GRIB API are found. If
+  they are not found and some actions are performed
+  on a GRIB file, the GRIB API will throw an
+  exception and R will crash. */
+  c = grib_context_get_default();
+  def_path = grib_context_full_defs_path(c, basename);
+  if (!def_path) {
+    error("gribr: GRIB definition files not found; Please set the GRIB_DEFINITION_PATH");
+  }
 
   p_fileName = CHAR(STRING_ELT(gribr_fileName, 0));
   input = fopen(p_fileName, "rb");

src/grib_select.c

@@ -4,6 +4,7 @@
 #include <string.h>
 
 #include "gribr.h"
+#include "grib_api_extra.h"
 
 SEXP gribr_select(SEXP gribr_filePath, SEXP gribr_keyList, SEXP gribr_isMulti) {
   int err;

src/gribr.h

@@ -40,6 +40,3 @@ void grewind(FILE* file);
 void gerror(const char *str, int err);
 SEXP getListElement(SEXP list, const char *str);
 SEXP gribr_message_from_handle(grib_handle *h, int isMulti);
-
-/* Extra GRIB API prototypes */
-void grib_index_rewind(grib_index* index);