ECC-777: Compiling with gcc and -std=c99 fails

tests/bufr_keys_iter.c

@@ -11,6 +11,9 @@
 #include "eccodes.h"
 #include <assert.h>
 
+extern char *optarg;
+extern int optind;
+
 static void usage(const char* prog)
 {
     printf("usage: %s [-a|-d] infile\n",prog);

tests/grib_util_set_spec.c

@@ -13,6 +13,9 @@
 #include <assert.h>
 #include <float.h>
 
+extern char *optarg;
+extern int optind;
+
 #define STR_EQUAL(s1, s2) (strcmp((s1), (s2)) == 0)
 
 static int get_packing_type_code(const char* packingType)

tools/codes_info.c

@@ -10,6 +10,9 @@
 
 #include "grib_tools.h"
 
+extern char *optarg;
+extern int optind;
+
 static void usage_and_exit(const char* progname) {
     printf("\nUsage: %s [-v] [-d] [-s]\n",progname);
     exit(1);

tools/grib_options.c

@@ -14,6 +14,9 @@
  */
 #include "grib_tools.h"
 
+extern char *optarg;
+extern int optind;
+
 #ifdef ECCODES_ON_WINDOWS
 /* Microsoft Windows Visual Studio support */
 #include "wingetopt.h"