-gboolean debug = 0;
-uint64_t limit_samples = 0;
-struct sr_output_format *output_format = NULL;
-int default_output_format = FALSE;
-char *output_format_param = NULL;
-char *input_format_param = NULL;
+static gboolean debug = 0;
+static uint64_t limit_samples = 0;
+static struct sr_output_format *output_format = NULL;
+static int default_output_format = FALSE;
+static char *output_format_param = NULL;
+static char *input_format_param = NULL;