Merge pull request #283 from commodo/json_pointer

json_pointer: add first revision based on RFC 6901

.gitignore

@@ -35,6 +35,7 @@
 /tests/test_set_value
 /tests/test_util_file
 /tests/test_visit
+/tests/test_json_pointer
 /tests/*.vg.out
 /tests/*.log
 /tests/*.trs

CMakeLists.txt

@@ -23,6 +23,7 @@ endif()
 include_directories(${CMAKE_CURRENT_BINARY_DIR}/include)
 
 set(JSON_C_HEADERS
+    ./compat/strdup.h
     ./json.h
     ${CMAKE_CURRENT_BINARY_DIR}/include/config.h
     ./json_config.h
@@ -31,6 +32,7 @@ set(JSON_C_HEADERS
     ./json_inttypes.h
     ./json_object.h
     ./json_object_private.h
+    ./json_pointer.h
     ./json_tokener.h
     ./json_util.h
     ./linkhash.h
@@ -43,6 +45,7 @@ set(JSON_C_SOURCES
     ./arraylist.c
     ./debug.c
     ./json_object.c
+    ./json_pointer.c
     ./json_tokener.c
     ./json_util.c
     ./linkhash.c

Makefile.am

@@ -18,6 +18,7 @@ libjson_cincludedir = $(includedir)/json-c
 libjson_cinclude_HEADERS = \
 	arraylist.h \
 	bits.h \
+	compat/strdup.h \
 	debug.h \
 	json.h \
 	json_c_version.h \
@@ -26,6 +27,7 @@ libjson_cinclude_HEADERS = \
 	json_object.h \
 	json_object_iterator.h \
 	json_object_private.h \
+	json_pointer.h \
 	json_tokener.h \
 	json_util.h \
 	json_visit.h \
@@ -42,6 +44,7 @@ libjson_c_la_SOURCES = \
 	json_c_version.c \
 	json_object.c \
 	json_object_iterator.c \
+	json_pointer.c \
 	json_tokener.c \
 	json_util.c \
 	json_visit.c \

compat/strdup.h

@@ -0,0 +1,13 @@
+#ifndef __STRDUP_H_COMPAT__
+#define __STRDUP_H_COMPAT__
+
+#include "../config.h"
+
+#if !defined(HAVE_STRDUP) && defined(_MSC_VER)
+  /* MSC has the version as _strdup */
+# define strdup _strdup
+#elif !defined(HAVE_STRDUP)
+# error You do not have strdup on your system.
+#endif /* HAVE_STRDUP */
+
+#endif /* __STRDUP_H_COMPAT__ */

json-c.vcproj

@@ -108,6 +108,9 @@ copy json_config.h.win32 json_config.h"/>
 			<File
 				RelativePath=".\json_object.c">
 			</File>
+			<File
+				RelativePath=".\json_pointer.c">
+			</File>
 			<File
 				RelativePath=".\json_tokener.c">
 			</File>
@@ -131,6 +134,9 @@ copy json_config.h.win32 json_config.h"/>
 			<File
 				RelativePath=".\bits.h">
 			</File>
+			<File
+				RelativePath=".\compat\strdup.h">
+			</File>
 			<File
 				RelativePath=".\debug.h">
 			</File>
@@ -140,6 +146,9 @@ copy json_config.h.win32 json_config.h"/>
 			<File
 				RelativePath=".\json_object_private.h">
 			</File>
+			<File
+				RelativePath=".\json_pointer.h">
+			</File>
 			<File
 				RelativePath=".\json_tokener.h">
 			</File>

json-c.vcxproj

@@ -133,6 +133,7 @@ copy json_config.h.win32 json_config.h
     <ClCompile Include="arraylist.c" />
     <ClCompile Include="debug.c" />
     <ClCompile Include="json_object.c" />
+    <ClCompile Include="json_pointer.c" />
     <ClCompile Include="json_tokener.c" />
     <ClCompile Include="json_util.c" />
     <ClCompile Include="linkhash.c" />
@@ -141,10 +142,12 @@ copy json_config.h.win32 json_config.h
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="arraylist.h" />
+    <ClInclude Include="compat\strdup.h" />
     <ClInclude Include="debug.h" />
     <ClInclude Include="json_inttypes.h" />
     <ClInclude Include="json_object.h" />
     <ClInclude Include="json_object_private.h" />
+    <ClInclude Include="json_pointer.h" />
     <ClInclude Include="json_tokener.h" />
     <ClInclude Include="json_util.h" />
     <ClInclude Include="linkhash.h" />
@@ -162,4 +165,4 @@ copy json_config.h.win32 json_config.h
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
+</Project>

json-c.vcxproj.filters

@@ -27,6 +27,9 @@
     <ClCompile Include="json_object.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="json_pointer.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="json_tokener.c">
       <Filter>Source Files</Filter>
     </ClCompile>
@@ -47,6 +50,9 @@
     <ClInclude Include="arraylist.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="compat\strdup.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
     <ClInclude Include="debug.h">
       <Filter>Header Files</Filter>
     </ClInclude>
@@ -56,6 +62,9 @@
     <ClInclude Include="json_object_private.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="json_pointer.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
     <ClInclude Include="json_tokener.h">
       <Filter>Header Files</Filter>
     </ClInclude>
@@ -87,4 +96,4 @@
     <None Include="README-WIN32.html" />
     <None Include="README.html" />
   </ItemGroup>
-</Project>
+</Project>

json.h

@@ -22,6 +22,7 @@ extern "C" {
 #include "arraylist.h"
 #include "json_util.h"
 #include "json_object.h"
+#include "json_pointer.h"
 #include "json_tokener.h"
 #include "json_object_iterator.h"
 #include "json_c_version.h"

json_object.c

@@ -29,13 +29,7 @@
 #include "json_object_private.h"
 #include "json_util.h"
 #include "math_compat.h"
-
-#if !defined(HAVE_STRDUP) && defined(_MSC_VER)
-  /* MSC has the version as _strdup */
-# define strdup _strdup
-#elif !defined(HAVE_STRDUP)
-# error You do not have strdup on your system.
-#endif /* HAVE_STRDUP */
+#include "compat/strdup.h"
 
 #if !defined(HAVE_SNPRINTF) && defined(_MSC_VER)
   /* MSC has the version as _snprintf */

json_pointer.c

@@ -0,0 +1,239 @@
+/*
+ * Copyright (c) 2016 Alexandru Ardelean.
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See COPYING for details.
+ *
+ */
+
+#include "config.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "json_pointer.h"
+
+/**
+ * JavaScript Object Notation (JSON) Pointer
+ *   RFC 6901 - https://tools.ietf.org/html/rfc6901
+ */
+
+static void string_replace_all_occurrences_with_char(char *s, const char *occur, char repl_char)
+{
+	int slen = strlen(s);
+	int skip = strlen(occur) - 1; /* length of the occurence, minus the char we're replacing */
+	char *p = s;
+	while ((p = strstr(p, occur))) {
+		*p = repl_char;
+		p++;
+		slen -= skip;
+		memcpy(p, (p + skip), slen - (p - s) + 1); /* includes null char too */
+	}
+}
+
+static int is_valid_index(struct json_object *jo, const char *path, int32_t *idx)
+{
+	int i, len = strlen(path);
+	/* this code-path optimizes a bit, for when we reference the 0-9 index range in a JSON array
+	   and because leading zeros not allowed */
+	if (len == 1) {
+		if (isdigit(path[0])) {
+			*idx = (path[0] - '0');
+			goto check_oob;
+		}
+		errno = EINVAL;
+		return 0;
+	}
+	/* leading zeros not allowed per RFC */
+	if (path[0] == '0') {
+		errno = EINVAL;
+		return 0;
+	}
+	/* RFC states base-10 decimals */
+	for (i = 0; i < len; i++) {
+		if (!isdigit(path[i])) {
+			errno = EINVAL;
+			return 0;
+		}
+	}
+
+	*idx = strtol(path, NULL, 10);
+	if (*idx < 0) {
+		errno = EINVAL;
+		return 0;
+	}
+check_oob:
+	len = json_object_array_length(jo);
+	if (*idx >= len) {
+		errno = ENOENT;
+		return 0;
+	}
+
+	return 1;
+}
+
+static int json_pointer_get_single_path(struct json_object *obj, char *path, struct json_object **value)
+{
+	if (json_object_is_type(obj, json_type_array)) {
+		int32_t idx;
+		if (!is_valid_index(obj, path, &idx))
+			return -1;
+		obj = json_object_array_get_idx(obj, idx);
+		if (obj) {
+			if (value)
+				*value = obj;
+			return 0;
+		}
+		/* Entry not found */
+		errno = ENOENT;
+		return -1;
+	}
+
+	/* RFC states that we first must eval all ~1 then all ~0 */
+	string_replace_all_occurrences_with_char(path, "~1", '/');
+	string_replace_all_occurrences_with_char(path, "~0", '~');
+
+	if (!json_object_object_get_ex(obj, path, value)) {
+		errno = ENOENT;
+		return -1;
+	}
+
+	return 0;
+}
+
+static int json_pointer_set_single_path(
+	struct json_object *parent,
+	const char *path,
+	struct json_object *value)
+{
+	if (json_object_is_type(parent, json_type_array)) {
+		int32_t idx;
+		/* RFC (Chapter 4) states that '-' may be used to add new elements to an array */
+		if (path[0] == '-' && path[1] == '\0')
+			return json_object_array_add(parent, value);
+		if (!is_valid_index(parent, path, &idx))
+			return -1;
+		return json_object_array_put_idx(parent, idx, value);
+	}
+
+	/* path replacements should have been done in json_pointer_get_single_path(),
+	   and we should still be good here */
+	if (json_object_is_type(parent, json_type_object))
+		return json_object_object_add(parent, path, value);
+
+	/* Getting here means that we tried to "dereference" a primitive JSON type (like string, int, bool).
+	   i.e. add a sub-object to it */
+	errno = ENOENT;
+	return -1;
+}
+
+static int json_pointer_get_recursive(
+	struct json_object *obj,
+	char *path,
+	struct json_object **value)
+{
+	char *endp;
+	int rc;
+
+	/* All paths (on each recursion level must have a leading '/' */
+	if (path[0] != '/') {
+		errno = EINVAL;
+		return -1;
+	}
+	path++;
+
+	endp = strchr(path, '/');
+	if (endp)
+		*endp = '\0';
+
+	/* If we err-ed here, return here */
+	if ((rc = json_pointer_get_single_path(obj, path, &obj)))
+		return rc;
+
+	if (endp) {
+		*endp = '/'; /* Put the slash back, so that the sanity check passes on next recursion level */
+		return json_pointer_get_recursive(obj, endp, value);
+	}
+
+	/* We should be at the end of the recursion here */
+    if (value)
+		*value = obj;
+
+	return 0;
+}
+
+int json_pointer_get(struct json_object *obj, const char *path, struct json_object **res)
+{
+	char *path_copy = NULL;
+	int rc;
+
+	if (!obj || !path) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (path[0] == '\0') {
+		if (res)
+			*res = obj;
+		return 0;
+	}
+
+	/* pass a working copy to the recursive call */
+	if (!(path_copy = strdup(path))) {
+		errno = ENOMEM;
+		return -1;
+	}
+	rc = json_pointer_get_recursive(obj, path_copy, res);
+	free(path_copy);
+
+	return rc;
+}
+
+int json_pointer_set(struct json_object **obj, const char *path, struct json_object *value)
+{
+	const char *endp;
+	char *path_copy = NULL;
+	struct json_object *set = NULL;
+	int rc;
+
+	if (!obj || !path) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (path[0] == '\0') {
+		json_object_put(*obj);
+		*obj = value;
+		return 0;
+	}
+
+	if (path[0] != '/') {
+		errno = EINVAL;
+		return -1;
+	}
+
+	/* If there's only 1 level to set, stop here */
+	if ((endp = strrchr(path, '/')) == path) {
+		path++;
+		return json_pointer_set_single_path(*obj, path, value);
+	}
+
+	/* pass a working copy to the recursive call */
+	if (!(path_copy = strdup(path))) {
+		errno = ENOMEM;
+		return -1;
+	}
+	path_copy[endp - path] = '\0';
+	rc = json_pointer_get_recursive(*obj, path_copy, &set);
+	free(path_copy);
+
+	if (rc)
+		return rc;
+
+	endp++;
+	return json_pointer_set_single_path(set, endp, value);
+}
+

json_pointer.h

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2016 Alexadru Ardelean.
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See COPYING for details.
+ *
+ */
+
+#ifndef _json_pointer_h_
+#define _json_pointer_h_
+
+#include "json_object.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * Retrieves a JSON sub-object from inside another JSON object
+ * using the JSON pointer notation as defined in RFC 6901
+ *   https://tools.ietf.org/html/rfc6901
+ *
+ * The returned JSON sub-object is equivalent to parsing manually the
+ * 'obj' JSON tree ; i.e. it's not a new object that is created, but rather
+ * a pointer inside the JSON tree.
+ *
+ * Internally, this is equivalent to doing a series of 'json_object_object_get()'
+ * and 'json_object_array_get_idx()' along the given 'path'.
+ *
+ * @param obj the json_object instance/tree from where to retrieve sub-objects
+ * @param path a (RFC6901) string notation for the sub-object to retrieve
+ * @param res a pointer where to store a reference to the json_object
+ *              associated with the given path
+ *
+ * @return negative if an error (or not found), or 0 if succeeded
+ */
+int json_pointer_get(struct json_object *obj, const char *path, struct json_object **res);
+
+/**
+ * Sets JSON object 'value' in the 'obj' tree at the location specified
+ * by the 'path'. 'path' is JSON pointer notation as defined in RFC 6901
+ *   https://tools.ietf.org/html/rfc6901
+ *
+ * Note that 'obj' is a double pointer, mostly for the "" (empty string)
+ * case, where the entire JSON object would be replaced by 'value'.
+ * In the case of the "" path, the object at '*obj' will have it's refcount
+ * decremented with 'json_object_put()' and the 'value' object will be assigned to it.
+ *
+ * For other cases (JSON sub-objects) ownership of 'value' will be transferred into
+ * '*obj' via 'json_object_object_add()' & 'json_object_array_put_idx()', so the
+ * only time the refcount should be decremented for 'value' is when the return value of
+ * 'json_pointer_set()' is negative (meaning the 'value' object did not get set into '*obj').
+ *
+ * That also implies that 'json_pointer_set()' does not do any refcount incrementing.
+ * (Just that single decrement that was mentioned above).
+ *
+ * @param obj the json_object instance/tree to which to add a sub-object
+ * @param path a (RFC6901) string notation for the sub-object to set in the tree
+ * @param value object to set at path
+ *
+ * @return negative if an error (or not found), or 0 if succeeded
+ */
+int json_pointer_set(struct json_object **obj, const char *path, struct json_object *value);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

json_tokener.c

@@ -31,6 +31,7 @@
 #include "json_object.h"
 #include "json_tokener.h"
 #include "json_util.h"
+#include "compat/strdup.h"
 
 #ifdef HAVE_LOCALE_H
 #include <locale.h>
@@ -41,13 +42,6 @@
 
 #define jt_hexdigit(x) (((x) <= '9') ? (x) - '0' : ((x) & 7) + 9)
 
-#if !HAVE_STRDUP && defined(_MSC_VER)
-  /* MSC has the version as _strdup */
-# define strdup _strdup
-#elif !HAVE_STRDUP
-# error You do not have strdup on your system.
-#endif /* HAVE_STRDUP */
-
 #if !HAVE_STRNCASECMP && defined(_MSC_VER)
   /* MSC has the version as _strnicmp */
 # define strncasecmp _strnicmp

tests/Makefile.am

@@ -23,6 +23,7 @@ TESTS+= test_set_serializer.test
 TESTS+= test_compare.test
 TESTS+= test_set_value.test
 TESTS+= test_visit.test
+TESTS+= test_json_pointer.test
 
 check_PROGRAMS=
 check_PROGRAMS += $(TESTS:.test=)

tests/strerror_override.c

@@ -50,7 +50,7 @@ static struct {
 
 #define PREFIX "ERRNO="
 static char errno_buf[128] = PREFIX;
-const char *strerror(int errno_in)
+char *strerror(int errno_in)
 {
 	int start_idx;
 	char digbuf[20];

tests/test_json_pointer.c

@@ -0,0 +1,272 @@
+#include <errno.h>
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "json.h"
+
+static void test_example_int(struct json_object *jo1, const char *json_pointer, int expected_int)
+{
+	struct json_object *jo2 = NULL;
+	assert(0 == json_pointer_get(jo1, json_pointer, NULL));
+	assert(0 == json_pointer_get(jo1, json_pointer, &jo2));
+	assert(json_object_is_type(jo2, json_type_int));
+	assert(expected_int == json_object_get_int(jo2));
+	printf("PASSED - GET -  %s == %d\n", json_pointer, expected_int);
+}
+
+static const char *input_json_str = "{ "
+	"'foo': ['bar', 'baz'], "
+	"'': 0, "
+	"'a/b': 1, "
+	"'c\%d': 2, "
+	"'e^f': 3, "
+	"'g|h': 4, "
+	"'i\\\\j': 5, "
+	"'k\\\"l': 6, "
+	"' ': 7, "
+	"'m~n': 8 "
+"}";
+
+
+static const char *rec_input_json_str = "{"
+	"'arr' : ["
+		"{"
+			"'obj': ["
+				"{},{},"
+				"{"
+					"'obj1': 0,"
+					"'obj2': \"1\""
+				"}"
+			"]"
+		"}"
+	"],"
+	"'obj' : {"
+		"'obj': {"
+			"'obj': ["
+				"{"
+					"'obj1': 0,"
+					"'obj2': \"1\""
+				"}"
+			"]"
+		"}"
+	"}"
+"}";
+
+/* Example from RFC */
+static void test_example_get()
+{
+	int i;
+	struct json_object *jo1, *jo2, *jo3;
+	struct json_pointer_map_s_i {
+		const char *s;
+		int i;
+	};
+	/* Create a map to iterate over for the ints */
+	struct json_pointer_map_s_i json_pointers[] = {
+		{ "/", 0 },
+		{ "/a~1b", 1 },
+		{"/c%d", 2 },
+		{"/e^f", 3 },
+		{ "/g|h", 4 },
+		{ "/i\\j", 5 },
+		{ "/k\"l", 6 },
+		{ "/ ", 7 },
+		{ "/m~0n", 8 },
+		{ NULL, 0}
+	};
+
+	jo1 = json_tokener_parse(input_json_str);
+	assert(NULL != jo1);
+	printf("PASSED - GET - LOADED TEST JSON\n");
+	printf("%s\n", json_object_get_string(jo1));
+
+	/* Test empty string returns entire object */
+	jo2 = NULL;
+	/* For each test, we're trying to see that NULL **value works (does no segfault) */
+	assert(0 == json_pointer_get(jo1, "", NULL));
+	assert(0 == json_pointer_get(jo1, "", &jo2));
+	assert(json_object_equal(jo2, jo1));
+	printf("PASSED - GET - ENTIRE OBJECT WORKED\n");
+
+	/* Test /foo == ['bar', 'baz']  */
+	jo3 = json_object_new_array();
+	json_object_array_add(jo3, json_object_new_string("bar"));
+	json_object_array_add(jo3, json_object_new_string("baz"));
+
+	jo2 = NULL;
+	assert(0 == json_pointer_get(jo1, "/foo", NULL));
+	assert(0 == json_pointer_get(jo1, "/foo", &jo2));
+	assert(NULL != jo2);
+	assert(json_object_equal(jo2, jo3));
+	json_object_put(jo3);
+	printf("PASSED - GET - /foo == ['bar', 'baz']\n");
+
+	/* Test /foo/0 == 'bar' */
+	jo2 = NULL;
+	assert(0 == json_pointer_get(jo1, "/foo/0", NULL));
+	assert(0 == json_pointer_get(jo1, "/foo/0", &jo2));
+	assert(NULL != jo2);
+	assert(0 == strcmp("bar", json_object_get_string(jo2)));
+	printf("PASSED - GET - /foo/0 == 'bar'\n");
+
+	for (i = 0 ; json_pointers[i].s; i++)
+		test_example_int(jo1, json_pointers[i].s, json_pointers[i].i);
+
+	json_object_put(jo1);
+}
+
+/* I'm not too happy with the RFC example to test the recusion of the json_pointer_get() function */
+static void test_recursion_get()
+{
+	struct json_object *jo2, *jo1 = json_tokener_parse(rec_input_json_str);
+
+	jo2 = NULL;
+	assert(jo1 != NULL);
+	printf("%s\n", json_object_get_string(jo1));
+	assert(0 == json_pointer_get(jo1, "/arr/0/obj/2/obj1", &jo2));
+	assert(json_object_is_type(jo2, json_type_int));
+	assert(0 == json_object_get_int(jo2));
+
+	assert(0 == json_pointer_get(jo1, "/arr/0/obj/2/obj2", &jo2));
+	assert(json_object_is_type(jo2, json_type_string));
+	assert(0 == strcmp("1", json_object_get_string(jo2)));
+
+	assert(jo1 != NULL);
+	assert(0 == json_pointer_get(jo1, "/obj/obj/obj/0/obj1", &jo2));
+	assert(json_object_is_type(jo2, json_type_int));
+	assert(0 == json_object_get_int(jo2));
+
+	assert(0 == json_pointer_get(jo1, "/obj/obj/obj/0/obj2", &jo2));
+	assert(json_object_is_type(jo2, json_type_string));
+	assert(0 == strcmp("1", json_object_get_string(jo2)));
+
+	printf("PASSED - GET - RECURSION TEST\n");
+
+	json_object_put(jo1);
+}
+
+static void test_wrong_inputs_get()
+{
+	struct json_object *jo2, *jo1 = json_tokener_parse(input_json_str);
+
+	assert(NULL != jo1);
+	printf("PASSED - GET - LOADED TEST JSON\n");
+	printf("%s\n", json_object_get_string(jo1));
+
+	/* Test leading '/' missing */
+	jo2 = NULL;
+	errno = 0;
+	assert(0 != json_pointer_get(jo1, "foo/bar", NULL));
+	assert(0 != json_pointer_get(jo1, "foo/bar", &jo2));
+	assert(errno == EINVAL);
+	assert(jo2 == NULL);
+	printf("PASSED - GET - MISSING /\n");
+
+	/* Test combinations of NULL params for input json & path */
+	errno = 0;
+	assert(0 != json_pointer_get(NULL, "foo/bar", NULL));
+	assert(errno == EINVAL);
+	errno = 0;
+	assert(0 != json_pointer_get(NULL, NULL, NULL));
+	assert(errno == EINVAL);
+	errno = 0;
+	assert(0 != json_pointer_get(jo1, NULL, NULL));
+	assert(errno == EINVAL);
+	printf("PASSED - GET - NULL INPUTS\n");
+
+	/* Test invalid indexes for array */
+	errno = 0;
+	assert(0 != json_pointer_get(jo1, "/foo/a", NULL));
+	assert(errno == EINVAL);
+	errno = 0;
+	assert(0 != json_pointer_get(jo1, "/foo/-", NULL));
+	assert(errno == EINVAL);
+	errno = 0;
+	/* Test optimized array path */
+	assert(0 != json_pointer_get(jo1, "/foo/4", NULL));
+	assert(errno == ENOENT);
+	errno = 0;
+	/* Test non-optimized array path */
+	assert(0 != json_pointer_get(jo1, "/foo/22", NULL));
+	assert(errno == ENOENT);
+	errno = 0;
+	assert(0 != json_pointer_get(jo1, "/foo/-1", NULL));
+	assert(errno == EINVAL);
+	errno = 0;
+	assert(0 != json_pointer_get(jo1, "/foo/10", NULL));
+	assert(errno == ENOENT);
+	printf("PASSED - GET - INVALID INDEXES\n");
+
+	json_object_put(jo1);
+}
+
+static void test_example_set()
+{
+	struct json_object *jo2, *jo1 = json_tokener_parse(input_json_str);
+
+	assert(jo1 != NULL);
+	printf("PASSED - SET - LOADED TEST JSON\n");
+	printf("%s\n", json_object_get_string(jo1));
+
+	assert(0 == json_pointer_set(&jo1, "/foo/1", json_object_new_string("cod")));
+	assert(0 == strcmp("cod", json_object_get_string(json_object_array_get_idx(json_object_object_get(jo1, "foo"), 1))));
+	printf("PASSED - SET - 'cod' in /foo/1\n");
+	assert(0 != json_pointer_set(&jo1, "/fud/gaw", (jo2 = json_tokener_parse("[1,2,3]"))));
+	assert(errno == ENOENT);
+	printf("PASSED - SET - non-existing /fud/gaw\n");
+	assert(0 == json_pointer_set(&jo1, "/fud", json_object_new_object()));
+	printf("PASSED - SET - /fud == {}\n");
+	assert(0 == json_pointer_set(&jo1, "/fud/gaw", jo2)); /* re-using jo2 from above */
+	printf("PASSED - SET - /fug/gaw == [1,2,3]\n");
+	assert(0 == json_pointer_set(&jo1, "/fud/gaw/0", json_object_new_int(0)));
+	printf("PASSED - SET - /fug/gaw == [0,2,3]\n");
+	assert(0 == json_pointer_set(&jo1, "/fud/gaw/-", json_object_new_int(4)));
+	printf("PASSED - SET - /fug/gaw == [0,2,3,4]\n");
+	assert(0 == json_pointer_set(&jo1, "/", json_object_new_int(9)));
+	printf("PASSED - SET - / == 9\n");
+
+	jo2 = json_tokener_parse("{ 'foo': [ 'bar', 'cod' ], '': 9, 'a/b': 1, 'c\%d': 2, 'e^f': 3, 'g|h': 4, 'i\\\\j': 5, 'k\\\"l': 6, ' ': 7, 'm~n': 8, 'fud': { 'gaw': [ 0, 2, 3, 4 ] } }");
+	assert(json_object_equal(jo2, jo1));
+	printf("PASSED - SET - Final JSON is: %s\n", json_object_get_string(jo1));
+	json_object_put(jo2);
+
+	assert(0 == json_pointer_set(&jo1, "", json_object_new_int(10)));
+	assert(10 == json_object_get_int(jo1));
+	printf("%s\n", json_object_get_string(jo1));
+
+	json_object_put(jo1);
+}
+
+static void test_wrong_inputs_set()
+{
+	struct json_object *jo2, *jo1 = json_tokener_parse(input_json_str);
+
+	assert(jo1 != NULL);
+	printf("PASSED - SET - LOADED TEST JSON\n");
+	printf("%s\n", json_object_get_string(jo1));
+
+	assert(0 != json_pointer_set(&jo1, "foo/bar", (jo2 = json_object_new_string("cod"))));
+	printf("PASSED - SET - failed 'cod' with path 'foo/bar'\n");
+	json_object_put(jo2);
+
+	assert(0 != json_pointer_set(&jo1, "/fud/gaw", (jo2 = json_object_new_string("whatever"))));
+	assert(0 == json_pointer_set(&jo1, "/fud", json_object_new_object()));
+	assert(0 == json_pointer_set(&jo1, "/fud/gaw", jo2)); /* re-using jo2 from above */
+	assert(0 != json_pointer_set(&jo1, "/fud/gaw/0", json_object_new_int(0)));
+	assert(0 != json_pointer_set(&jo1, "/fud/gaw/", json_object_new_int(0)));
+	printf("PASSED - SET - failed to set index to non-array\n");
+
+	json_object_put(jo1);
+	json_object_put(jo2);
+}
+
+int main(int argc, char **argv)
+{
+	test_example_get();
+	test_recursion_get();
+	test_wrong_inputs_get();
+	test_example_set();
+	test_wrong_inputs_set();
+	return 0;
+}

tests/test_json_pointer.expected

@@ -0,0 +1,36 @@
+PASSED - GET - LOADED TEST JSON
+{ "foo": [ "bar", "baz" ], "": 0, "a\/b": 1, "c%d": 2, "e^f": 3, "g|h": 4, "i\\j": 5, "k\"l": 6, " ": 7, "m~n": 8 }
+PASSED - GET - ENTIRE OBJECT WORKED
+PASSED - GET - /foo == ['bar', 'baz']
+PASSED - GET - /foo/0 == 'bar'
+PASSED - GET -  / == 0
+PASSED - GET -  /a~1b == 1
+PASSED - GET -  /c%d == 2
+PASSED - GET -  /e^f == 3
+PASSED - GET -  /g|h == 4
+PASSED - GET -  /i\j == 5
+PASSED - GET -  /k"l == 6
+PASSED - GET -  /  == 7
+PASSED - GET -  /m~0n == 8
+{ "arr": [ { "obj": [ { }, { }, { "obj1": 0, "obj2": "1" } ] } ], "obj": { "obj": { "obj": [ { "obj1": 0, "obj2": "1" } ] } } }
+PASSED - GET - RECURSION TEST
+PASSED - GET - LOADED TEST JSON
+{ "foo": [ "bar", "baz" ], "": 0, "a\/b": 1, "c%d": 2, "e^f": 3, "g|h": 4, "i\\j": 5, "k\"l": 6, " ": 7, "m~n": 8 }
+PASSED - GET - MISSING /
+PASSED - GET - NULL INPUTS
+PASSED - GET - INVALID INDEXES
+PASSED - SET - LOADED TEST JSON
+{ "foo": [ "bar", "baz" ], "": 0, "a\/b": 1, "c%d": 2, "e^f": 3, "g|h": 4, "i\\j": 5, "k\"l": 6, " ": 7, "m~n": 8 }
+PASSED - SET - 'cod' in /foo/1
+PASSED - SET - non-existing /fud/gaw
+PASSED - SET - /fud == {}
+PASSED - SET - /fug/gaw == [1,2,3]
+PASSED - SET - /fug/gaw == [0,2,3]
+PASSED - SET - /fug/gaw == [0,2,3,4]
+PASSED - SET - / == 9
+PASSED - SET - Final JSON is: { "foo": [ "bar", "cod" ], "": 9, "a\/b": 1, "c%d": 2, "e^f": 3, "g|h": 4, "i\\j": 5, "k\"l": 6, " ": 7, "m~n": 8, "fud": { "gaw": [ 0, 2, 3, 4 ] } }
+10
+PASSED - SET - LOADED TEST JSON
+{ "foo": [ "bar", "baz" ], "": 0, "a\/b": 1, "c%d": 2, "e^f": 3, "g|h": 4, "i\\j": 5, "k\"l": 6, " ": 7, "m~n": 8 }
+PASSED - SET - failed 'cod' with path 'foo/bar'
+PASSED - SET - failed to set index to non-array

tests/test_json_pointer.test

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+# Common definitions
+if test -z "$srcdir"; then
+    srcdir="${0%/*}"
+    test "$srcdir" = "$0" && srcdir=.
+    test -z "$srcdir" && srcdir=.
+fi
+. "$srcdir/test-defs.sh"
+
+run_output_test test_json_pointer
+exit $?