use system jansson if available

client/src/jansson_path.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef JANSSON_PATH_H
+#define JANSSON_PATH_H
+
+//#include <stdio.h>
+#include <stdlib.h>  /* for size_t */
+//#include <stdarg.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+json_t *json_path_get(const json_t *json, const char *path);
+int json_path_set_new(json_t *json, const char *path, json_t *value, size_t flags, json_error_t *error);
+
+static JSON_INLINE
+int json_path_set(json_t *json, const char *path, json_t *value, size_t flags, json_error_t *error) {
+    return json_path_set_new(json, path, json_incref(value), flags, error);
+}
+
+#ifdef __cplusplus
+}
+#endif
+#endif