不可不知的JSON處理庫（cJSON）

ANSI C中的超輕量級JSON解析器

JSON（JavaScript物件表示法）是一種輕量級的資料交換格式。人類易於閱讀和書寫。機器很容易解析和生成。它基於JavaScript程式語言標準ECMA-262第三版（1999年12月）的子集 。JSON是一種完全獨立於語言的文字格式，但是使用C語言家族（包括C，C ++，C＃，Java，JavaScript，Perl，Python等）的程式設計師熟悉的約定。這些屬性使JSON成為理想的資料交換語言。

cJSON旨在成為您可以完成工作的最簡單的解析器。它是資源只有一個C的標頭檔案和C檔案，所以方便移植。它可以為你各種需要的json字串處理，包括打包、解析、修改、刪除、新增等。在這裡將一探究竟。

在這裡將著重敘述json的打包和解析，更多處理玩法，見文章末尾連結。

開始cJSON

cJSON合併到您的專案

因為整個庫只有一個C檔案和一個標頭檔案，所以您只需複製cJSON.h並複製cJSON.c到專案源並開始使用它。

cJSON用ANSI C（C89）編寫，以便支援儘可能多的平臺和編譯器。

 

下載：

https://github.com/DaveGamble/cJSON/releases

 

Cjson結構體

/* The cJSON structure: */
typedef struct cJSON
{
    struct cJSON *next;
    struct cJSON *prev;
    struct cJSON *child;
    int type;
    char *valuestring;
    int valueint;
    double valuedouble;
    char *string;
} cJSON;

結構體項解析：

next 和prev ：Cjson結構體作為一個雙向連表的環，可以通過 next 和prev 指標進行連表遍歷

child：可以是cJSON_Array、cJSON_Object型別資料

type：當前項的型別

valuestring：內容儲存，當型別是cJSON_String和cJSON_Raw

valueint：內容儲存，整型，可以是cJSON_False、cJSON_True資料

valuedouble：內容儲存，浮點型，當型別是cJSON_Number

string：鍵名

資料型別

l  cJSON_Invalid表示一個不包含任何值的無效專案。如果將專案設定為全零位元組，則將自動具有此型別。

l  cJSON_False表示一個false布林值。您也可以使用來檢查布林值cJSON_IsBool

l  cJSON_True表示一個true布林值。您也可以使用來檢查布林值cJSON_IsBool

l  cJSON_NULL表示一個null值

l  cJSON_Number 表示一個數字值。該值儲存為double in valuedouble和in valueint。如果數字超出整數範圍，INT_MAX或INT_MIN用於valueint

l  cJSON_String表示一個字串值。它以零終止字串的形式儲存在中valuestring

l  cJSON_Array表示一個陣列值。這是通過指向表示陣列中值child的cJSON專案的連結列表來實現的。使用next和將元素連結在一起prev，其中第一個元素具有prev.next == NULL和最後一個元素next == NULL

l  cJSON_Object 表示一個物件值。物件的儲存方式與陣列相同，唯一的區別是物件中的項將其鍵儲存在中string

l  cJSON_Raw表示以JSON字元儲存的零終止形式的任何JSON valuestring。例如，可以使用它來避免一遍又一遍地列印相同的靜態JSON以節省效能。解析時，cJSON永遠不會建立此型別。另請注意，cJSON不會檢查其是否為有效JSON。

型別

#define cJSON_Invalid (0)
#define cJSON_False  (1 << 0)
#define cJSON_True   (1 << 1)
#define cJSON_NULL   (1 << 2)
#define cJSON_Number (1 << 3)
#define cJSON_String (1 << 4)
#define cJSON_Array  (1 << 5)
#define cJSON_Object (1 << 6)
#define cJSON_Raw    (1 << 7) /* raw json */

型別判斷

cJSON_IsInvalid(const cJSON * const item);
cJSON_IsFalse(const cJSON * const item);
cJSON_IsTrue(const cJSON * const item);
cJSON_IsBool(const cJSON * const item);
cJSON_IsNull(const cJSON * const item);
cJSON_IsNumber(const cJSON * const item);
cJSON_IsString(const cJSON * const item);
cJSON_IsArray(const cJSON * const item);
cJSON_IsObject(const cJSON * const item);
cJSON_IsRaw(const cJSON * const item);

注意

建立cjson物件後，處理完需要進行記憶體釋放：

如果是cjson裡的物件，請使用cJSON_Delete()

如果不是物件：cJSON_free()或free()

 

零字元

cJSON不支援包含零字元'\0'或的字串\u0000。對於當前的API，這是不可能的，因為字串以零結尾。

 

字元編碼

cJSON僅支援UTF-8編碼的輸入。但是在大多數情況下，它不會拒絕無效的UTF-8作為輸入，而只是將其原樣傳播。只要輸入不包含無效的UTF-8，輸出將始終是有效的UTF-8。

 

C標準

cJSON用ANSI C（或C89，C90）編寫。如果您的編譯器或C庫未遵循此標準，則不能保證正確的行為。

 

注意：ANSI C不是C ++，因此不應使用C ++編譯器進行編譯。您可以使用C編譯器對其進行編譯，然後將其與C ++程式碼連結。儘管可以使用C ++編譯器進行編譯，但是不能保證正確的行為。

 

浮點數字

double除IEEE754雙精度浮點數外，cJSON不正式支援任何實現。它可能仍然可以與其他實現一起使用，但是這些實現的錯誤將被視為無效。

 

目前，cJSON支援的浮點文字的最大長度為63個字元。

 

陣列和物件的深層巢狀

cJSON不支援巢狀太深的陣列和物件，因為這會導致堆疊溢位。為了防止這種CJSON_NESTING_LIMIT情況，預設情況下，cJSON將深度限制為1000，但是可以在編譯時進行更改。

格式化輸出

按標準的格式輸出json字串，輸出完後一定要記得釋放記憶體

 程式碼

#include <stdio.h>
#include "cJSON.h"
#include "cJSON.c"
void main(){
    //待解析字串 
    char *json_str="{\"key1\":\"dongxiaodong\",\"key2\":1998,\"key3\":55778}";
    
    //輸出原字串
    printf("原字串：%s\r\n",json_str); 

    //解析成json物件 
    cJSON * json_obj = cJSON_Parse(json_str); 

    //格式輸出
    char *json_print_str=NULL;
    json_print_str=cJSON_Print(json_obj);
    printf("\r\n輸出內容：\r\n\r\n%s\r\n",json_print_str);
    
    //釋放資源 
    free(json_print_str);
    
    //釋放資源 
    cJSON_Delete(json_obj);
}

json打包

cJSON_CreateObject函式可建立一個根資料項，在此之後就可以新增各種資料型別的子節點了，使用完成後需要通過cJSON_Delete()釋放記憶體。

建立一層級的json

 程式碼：

#include <stdio.h>
#include "cJSON.h"
#include "cJSON.c"
void main(){
    cJSON *root_obj = NULL;//根，json物件 
    char *out_str = NULL; //輸出結果 
    root_obj =cJSON_CreateObject();//建立 
     //新增一個字串，引數（根物件，鍵，值） 
    cJSON_AddStringToObject(root_obj, "key1", "dongxiaodong");
    //新增一個整型，引數（根物件，鍵，值） 
    cJSON_AddNumberToObject(root_obj, "key2",1998);
    //新增一個浮點型，引數（根物件，鍵，值） 
    cJSON_AddNumberToObject(root_obj, "key3",22.33);
    //新增一個bool型別，引數（根物件，鍵，值） 
    //bool值可以是0/1或false/true 
    cJSON_AddBoolToObject(root_obj, "key4",0);
    //將json物件打包成字串 
    out_str = cJSON_PrintUnformatted(root_obj);
    //銷燬json物件，釋放記憶體 
    cJSON_Delete(root_obj); 
    //輸出值：{"key1":"dongxiaodong","key2":1998,"key3":22.33,"key4":false} 
    printf("%s",out_str);
}

型別建立函式還有：

cJSON_AddNullToObject(cJSON * const object, const char * const name);

cJSON_AddTrueToObject(cJSON * const object, const char * const name);

cJSON_AddFalseToObject(cJSON * const object, const char * const name);

cJSON_AddBoolToObject(cJSON * const object, const char * const name, const cJSON_bool boolean);

cJSON_AddNumberToObject(cJSON * const object, const char * const name, const double number);

cJSON_AddStringToObject(cJSON * const object, const char * const name, const char * const string);

cJSON_AddRawToObject(cJSON * const object, const char * const name, const char * const raw);

cJSON_AddObjectToObject(cJSON * const object, const char * const name);

cJSON_AddArrayToObject(cJSON * const object, const char * const name);

建立多層級的json

 程式碼：

#include <stdio.h>
#include "cJSON.h"
#include "cJSON.c"
void main(){
    cJSON *root_obj = NULL;//根，json物件 
    cJSON *item_obj = NULL;//二級json物件 
    char *out_str = NULL; //輸出結果 
    
    root_obj =cJSON_CreateObject();//建立 
     //新增一個字串，引數（根物件，鍵，值） 
    cJSON_AddStringToObject(root_obj, "key1", "dongxiaodong");
    //新增一個整型，引數（根物件，鍵，值） 
    cJSON_AddNumberToObject(root_obj, "key2",1998);
    
    //建立一個子json物件
    item_obj= cJSON_AddObjectToObject(root_obj,"myson"); 
    //向孩子物件中新增內容
    cJSON_AddStringToObject(item_obj, "sonkey1", "東小東"); 
    cJSON_AddNumberToObject(item_obj, "sonkey2",2020);
      
    //將json物件打包成字串 
    out_str = cJSON_PrintUnformatted(root_obj);
    //銷燬json物件，釋放記憶體 
    cJSON_Delete(root_obj); 
    //輸出值：{"key1":"dongxiaodong","key2":1998,"myson":{"sonkey1":"東小東","sonkey2":2020}}
    printf("%s",out_str);
}

建立多層json(陣列形式)

 

 程式碼

#include <stdio.h>
#include "cJSON.h"
#include "cJSON.c"
void main(){
    cJSON *root_obj = NULL;//根，json物件 
    cJSON *item_obj = NULL;//陣列物件 
    char *out_str = NULL; //輸出結果 
    
    root_obj =cJSON_CreateObject();//建立 
     //新增一個字串，引數（根物件，鍵，值） 
    cJSON_AddStringToObject(root_obj, "key1", "dongxiaodong");
    //新增一個整型，引數（根物件，鍵，值） 
    cJSON_AddNumberToObject(root_obj, "key2",1998);
    
    //建立一個子陣列物件 
    item_obj= cJSON_AddArrayToObject(root_obj,"myson"); 
    //向陣列物件中新增內容
    cJSON_AddItemToArray(item_obj,cJSON_CreateTrue()); 
    cJSON_AddItemToArray(item_obj,cJSON_CreateNumber(22));
      
    //將json物件打包成字串 
    out_str = cJSON_PrintUnformatted(root_obj);
    //銷燬json物件，釋放記憶體 
    cJSON_Delete(root_obj); 
    //輸出值：{"key1":"dongxiaodong","key2":1998,"myson":[true,22]}
    printf("%s",out_str);
}

建立的物件還可以是下面這些

cJSON_CreateNull(void);

cJSON_CreateTrue(void);

cJSON_CreateFalse(void);

cJSON_CreateBool(cJSON_bool boolean);

cJSON_CreateNumber(double num);

cJSON_CreateString(const char *string);

cJSON_CreateRaw(const char *raw);

cJSON_CreateArray(void);

cJSON_CreateObject(void);

建立混合json

 程式碼

#include <stdio.h>
#include "cJSON.h"
#include "cJSON.c"
void main(){
    cJSON *root_obj = NULL;//根，json物件 
    cJSON *son_obj=NULL; 
    cJSON *item_obj = NULL;//陣列物件 
    char *out_str = NULL; //輸出結果 
    
    //根物件 
    root_obj =cJSON_CreateObject();//建立 
    //新增一個字串，引數（根物件，鍵，值） 
    cJSON_AddStringToObject(root_obj, "key1", "dongxiaodong");
    //新增一個整型，引數（根物件，鍵，值） 
    cJSON_AddNumberToObject(root_obj, "key2",1998);
    
    //建立一個子陣列物件 
    item_obj= cJSON_AddArrayToObject(root_obj,"myson"); 
    //向陣列物件中新增內容
    cJSON_AddItemToArray(item_obj,cJSON_CreateTrue()); 
    cJSON_AddItemToArray(item_obj,cJSON_CreateNumber(22));
    
    //子物件 
    son_obj =cJSON_CreateObject();//建立 
    //新增一個字串，引數（根物件，鍵，值） 
    cJSON_AddStringToObject(son_obj, "son1", "dongxiaodong");
    //新增一個整型，引數（根物件，鍵，值） 
    cJSON_AddNumberToObject(son_obj, "son2",1998);
    cJSON_AddItemToArray(item_obj,son_obj);
    
    //將json物件打包成字串 
    out_str = cJSON_PrintUnformatted(root_obj);
    //銷燬json物件，釋放記憶體 
    cJSON_Delete(root_obj); 
    //輸出值：{"key1":"dongxiaodong","key2":1998,"myson":[true,22,{"son1":"dongxiaodong","son2":1998}]}
    printf("%s",out_str);
}

json解析

解析一層級的json

 

程式碼：

#include <stdio.h>
#include "cJSON.h"
#include "cJSON.c"
void main(){
    //待解析字串 
    char *json_str="{\"key1\":\"dongxiaodong\",\"key2\":1998,\"key3\":22.33,\"key4\":true}";
    //解析成json物件 
    cJSON * json_obj = cJSON_Parse(json_str); 
    
    //項儲存 
    cJSON *item=NULL;
    
    //輸出原字串
    printf("原字串：%s\r\n",json_str); 
    
    //獲取string型別 
    item=cJSON_GetObjectItem(json_obj,"key1");  
    printf("\r\nkey1：%s\r\n",item->valuestring);
    cJSON_Delete(item);//釋放資源 
     
    //獲取數字 
    item=cJSON_GetObjectItem(json_obj,"key2");  
    printf("\r\nkey2：%d\r\n",item->valueint);
    cJSON_Delete(item);//釋放資源 
    
    //獲取數字 
    item=cJSON_GetObjectItem(json_obj,"key3");  
    printf("\r\nkey3：%f\r\n",item->valuedouble);
    cJSON_Delete(item);//釋放資源 
    
    //獲取bool 
    item=cJSON_GetObjectItem(json_obj,"key4");  
    printf("\r\nkey4：%d\r\n",item->valueint);
    cJSON_Delete(item);//釋放資源 
    
    //是否資源 
    cJSON_Delete(json_obj);
}

解析多層級的json

 

程式碼

#include <stdio.h>
#include "cJSON.h"
#include "cJSON.c"
void main(){
    //待解析字串 
    char *json_str="{\"key1\":\"dongxiaodong\",\"key2\":1998,\"myson\":{\"sonkey1\":\"東小東\",\"sonkey2\":2020}}";
    //解析成json物件 
    cJSON * json_obj = cJSON_Parse(json_str); 
    
    //項儲存 
    cJSON *item=NULL;
    //內部項儲存
    cJSON * item_item=NULL; 
    
    //輸出原字串
    printf("原字串：%s\r\n",json_str); 
    
    //獲取string型別 
    item=cJSON_GetObjectItem(json_obj,"key1");  
    printf("\r\nkey1：%s\r\n",item->valuestring);
    cJSON_Delete(item);//釋放資源 
     
    //獲取數字 
    item=cJSON_GetObjectItem(json_obj,"key2");  
    printf("\r\nkey2：%d\r\n",item->valueint);
    cJSON_Delete(item);//釋放資源 
    
    //子串
    item=cJSON_GetObjectItem(json_obj,"myson");  
    item_item=cJSON_GetObjectItem(item,"sonkey1"); 
    printf("\r\nmyson(sonkey1)：%s\r\n",item_item->valuestring);
    cJSON_Delete(item_item);//釋放資源 
    
    item_item=cJSON_GetObjectItem(item,"sonkey2"); 
    printf("\r\nmyson(sonkey2)：%d\r\n",item_item->valueint);
    cJSON_Delete(item_item);//釋放資源 
    
    cJSON_Delete(item);//釋放資源 
    
    //釋放資源 
    cJSON_Delete(json_obj);
}

 解析多層json(陣列形式)

  

程式碼

#include <stdio.h>
#include "cJSON.h"
#include "cJSON.c"
void main(){
    //待解析字串 
    char *json_str="{\"key1\":\"dongxiaodong\",\"key2\":1998,\"myson\":[true,113]}";
    //解析成json物件 
    cJSON * json_obj = cJSON_Parse(json_str); 
    
    //項儲存 
    cJSON *item=NULL;
    //內部項儲存
    cJSON * item_item=NULL; 
    
    //輸出原字串
    printf("原字串：%s\r\n",json_str); 
    
    //獲取string型別 
    item=cJSON_GetObjectItem(json_obj,"key1");  
    printf("\r\nkey1：%s\r\n",item->valuestring);
    cJSON_Delete(item);//釋放資源 
     
    //獲取數字 
    item=cJSON_GetObjectItem(json_obj,"key2");  
    printf("\r\nkey2：%d\r\n",item->valueint);
    cJSON_Delete(item);//釋放資源 
    
    //獲取子串 
    item=cJSON_GetObjectItem(json_obj,"myson"); 
    
    //輸出陣列大小 
    printf("\r\n陣列大小：%d\r\n",cJSON_GetArraySize(item));
    
    //輸出項1內容 
    item_item=cJSON_GetArrayItem(item,0); 
    printf("\r\nmyson(0)：%d\r\n",item_item->valueint);
    //cJSON_Delete(item_item);//釋放資源 
    
    //輸出項2內容 
    item_item=cJSON_GetArrayItem(item,1);
    printf("\r\nmyson(1)：%d\r\n",item_item->valueint);
    cJSON_Delete(item_item);//釋放資源 
    
    cJSON_Delete(item);//釋放資源 
    
    //釋放資源 
    cJSON_Delete(json_obj);
}

  解析混合json

程式碼

#include <stdio.h>
#include "cJSON.h"
#include "cJSON.c"
void main(){
    //待解析字串 
    char *json_str="{\"key1\":\"dongxiaodong\",\"key2\":1998,\"myson\":[true,22,{\"son1\":\"dongxiaodong\",\"son2\":1998}]}";
    //解析成json物件 
    cJSON * json_obj = cJSON_Parse(json_str); 
    
    //項儲存 
    cJSON *item=NULL;
    //內部項儲存
    cJSON * item_item=NULL; 
    
    //輸出原字串
    printf("原字串：%s\r\n",json_str); 
    
    //獲取string型別 
    item=cJSON_GetObjectItem(json_obj,"key1");  
    printf("\r\nkey1：%s\r\n",item->valuestring);
    cJSON_Delete(item);//釋放資源 
     
    //獲取數字 
    item=cJSON_GetObjectItem(json_obj,"key2");  
    printf("\r\nkey2：%d\r\n",item->valueint);
    cJSON_Delete(item);//釋放資源 
    
    //獲取子串 
    item=cJSON_GetObjectItem(json_obj,"myson"); 
    
    //輸出陣列大小 
    printf("\r\n陣列大小：%d\r\n",cJSON_GetArraySize(item));
    
    //輸出項1內容 
    item_item=cJSON_GetArrayItem(item,0); 
    printf("\r\nmyson(0)：%d\r\n",item_item->valueint);
    //cJSON_Delete(item_item);//釋放資源 
    
    //輸出項2內容 
    item_item=cJSON_GetArrayItem(item,1);
    printf("\r\nmyson(1)：%d\r\n",item_item->valueint);
    cJSON_Delete(item_item);//釋放資源 
    
    //項3內容
    item_item=cJSON_GetArrayItem(item,2); 
    cJSON *item_item_son=NULL;
    
    item_item_son =cJSON_GetObjectItem(item_item,"son1");  
    printf("\r\nmyson(2)(son1）：%s\r\n",item_item_son->valuestring);
    cJSON_Delete(item_item_son);//釋放資源 
    
    item_item_son =cJSON_GetObjectItem(item_item,"son2");  
    printf("\r\nmyson(2)(son2）：%d\r\n",item_item_son->valueint);
    cJSON_Delete(item_item_son);//釋放資源
    cJSON_Delete(item_item);//釋放資源   
    
    cJSON_Delete(item);//釋放資源 
    
    //釋放資源 
    cJSON_Delete(json_obj);
}

 附件：

cJSON.h

/*
  Copyright (c) 2009-2017 Dave Gamble and cJSON contributors

  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:

  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  THE SOFTWARE.
*/

#ifndef cJSON__h
#define cJSON__h

#ifdef __cplusplus
extern "C"
{
#endif

#if !defined(__WINDOWS__) && (defined(WIN32) || defined(WIN64) || defined(_MSC_VER) || defined(_WIN32))
#define __WINDOWS__
#endif

#ifdef __WINDOWS__

/* When compiling for windows, we specify a specific calling convention to avoid issues where we are being called from a project with a different default calling convention.  For windows you have 3 define options:

CJSON_HIDE_SYMBOLS - Define this in the case where you don't want to ever dllexport symbols
CJSON_EXPORT_SYMBOLS - Define this on library build when you want to dllexport symbols (default)
CJSON_IMPORT_SYMBOLS - Define this if you want to dllimport symbol

For *nix builds that support visibility attribute, you can define similar behavior by

setting default visibility to hidden by adding
-fvisibility=hidden (for gcc)
or
-xldscope=hidden (for sun cc)
to CFLAGS

then using the CJSON_API_VISIBILITY flag to "export" the same symbols the way CJSON_EXPORT_SYMBOLS does

*/

#define CJSON_CDECL __cdecl
#define CJSON_STDCALL __stdcall

/* export symbols by default, this is necessary for copy pasting the C and header file */
#if !defined(CJSON_HIDE_SYMBOLS) && !defined(CJSON_IMPORT_SYMBOLS) && !defined(CJSON_EXPORT_SYMBOLS)
#define CJSON_EXPORT_SYMBOLS
#endif

#if defined(CJSON_HIDE_SYMBOLS)
#define CJSON_PUBLIC(type)   type CJSON_STDCALL
#elif defined(CJSON_EXPORT_SYMBOLS)
#define CJSON_PUBLIC(type)   __declspec(dllexport) type CJSON_STDCALL
#elif defined(CJSON_IMPORT_SYMBOLS)
#define CJSON_PUBLIC(type)   __declspec(dllimport) type CJSON_STDCALL
#endif
#else /* !__WINDOWS__ */
#define CJSON_CDECL
#define CJSON_STDCALL

#if (defined(__GNUC__) || defined(__SUNPRO_CC) || defined (__SUNPRO_C)) && defined(CJSON_API_VISIBILITY)
#define CJSON_PUBLIC(type)   __attribute__((visibility("default"))) type
#else
#define CJSON_PUBLIC(type) type
#endif
#endif

/* project version */
#define CJSON_VERSION_MAJOR 1
#define CJSON_VERSION_MINOR 7
#define CJSON_VERSION_PATCH 13

#include <stddef.h>

/* cJSON Types: */
#define cJSON_Invalid (0)
#define cJSON_False  (1 << 0)
#define cJSON_True   (1 << 1)
#define cJSON_NULL   (1 << 2)
#define cJSON_Number (1 << 3)
#define cJSON_String (1 << 4)
#define cJSON_Array  (1 << 5)
#define cJSON_Object (1 << 6)
#define cJSON_Raw    (1 << 7) /* raw json */

#define cJSON_IsReference 256
#define cJSON_StringIsConst 512

/* The cJSON structure: */
typedef struct cJSON
{
    /* next/prev allow you to walk array/object chains. Alternatively, use GetArraySize/GetArrayItem/GetObjectItem */
    struct cJSON *next;
    struct cJSON *prev;
    /* An array or object item will have a child pointer pointing to a chain of the items in the array/object. */
    struct cJSON *child;

    /* The type of the item, as above. */
    int type;

    /* The item's string, if type==cJSON_String  and type == cJSON_Raw */
    char *valuestring;
    /* writing to valueint is DEPRECATED, use cJSON_SetNumberValue instead */
    int valueint;
    /* The item's number, if type==cJSON_Number */
    double valuedouble;

    /* The item's name string, if this item is the child of, or is in the list of subitems of an object. */
    char *string;
} cJSON;

typedef struct cJSON_Hooks
{
      /* malloc/free are CDECL on Windows regardless of the default calling convention of the compiler, so ensure the hooks allow passing those functions directly. */
      void *(CJSON_CDECL *malloc_fn)(size_t sz);
      void (CJSON_CDECL *free_fn)(void *ptr);
} cJSON_Hooks;

typedef int cJSON_bool;

/* Limits how deeply nested arrays/objects can be before cJSON rejects to parse them.
 * This is to prevent stack overflows. */
#ifndef CJSON_NESTING_LIMIT
#define CJSON_NESTING_LIMIT 1000
#endif

/* returns the version of cJSON as a string */
CJSON_PUBLIC(const char*) cJSON_Version(void);

/* Supply malloc, realloc and free functions to cJSON */
CJSON_PUBLIC(void) cJSON_InitHooks(cJSON_Hooks* hooks);

/* Memory Management: the caller is always responsible to free the results from all variants of cJSON_Parse (with cJSON_Delete) and cJSON_Print (with stdlib free, cJSON_Hooks.free_fn, or cJSON_free as appropriate). The exception is cJSON_PrintPreallocated, where the caller has full responsibility of the buffer. */
/* Supply a block of JSON, and this returns a cJSON object you can interrogate. */
CJSON_PUBLIC(cJSON *) cJSON_Parse(const char *value);
CJSON_PUBLIC(cJSON *) cJSON_ParseWithLength(const char *value, size_t buffer_length);
/* ParseWithOpts allows you to require (and check) that the JSON is null terminated, and to retrieve the pointer to the final byte parsed. */
/* If you supply a ptr in return_parse_end and parsing fails, then return_parse_end will contain a pointer to the error so will match cJSON_GetErrorPtr(). */
CJSON_PUBLIC(cJSON *) cJSON_ParseWithOpts(const char *value, const char **return_parse_end, cJSON_bool require_null_terminated);
CJSON_PUBLIC(cJSON *) cJSON_ParseWithLengthOpts(const char *value, size_t buffer_length, const char **return_parse_end, cJSON_bool require_null_terminated);

/* Render a cJSON entity to text for transfer/storage. */
CJSON_PUBLIC(char *) cJSON_Print(const cJSON *item);
/* Render a cJSON entity to text for transfer/storage without any formatting. */
CJSON_PUBLIC(char *) cJSON_PrintUnformatted(const cJSON *item);
/* Render a cJSON entity to text using a buffered strategy. prebuffer is a guess at the final size. guessing well reduces reallocation. fmt=0 gives unformatted, =1 gives formatted */
CJSON_PUBLIC(char *) cJSON_PrintBuffered(const cJSON *item, int prebuffer, cJSON_bool fmt);
/* Render a cJSON entity to text using a buffer already allocated in memory with given length. Returns 1 on success and 0 on failure. */
/* NOTE: cJSON is not always 100% accurate in estimating how much memory it will use, so to be safe allocate 5 bytes more than you actually need */
CJSON_PUBLIC(cJSON_bool) cJSON_PrintPreallocated(cJSON *item, char *buffer, const int length, const cJSON_bool format);
/* Delete a cJSON entity and all subentities. */
CJSON_PUBLIC(void) cJSON_Delete(cJSON *item);

/* Returns the number of items in an array (or object). */
CJSON_PUBLIC(int) cJSON_GetArraySize(const cJSON *array);
/* Retrieve item number "index" from array "array". Returns NULL if unsuccessful. */
CJSON_PUBLIC(cJSON *) cJSON_GetArrayItem(const cJSON *array, int index);
/* Get item "string" from object. Case insensitive. */
CJSON_PUBLIC(cJSON *) cJSON_GetObjectItem(const cJSON * const object, const char * const string);
CJSON_PUBLIC(cJSON *) cJSON_GetObjectItemCaseSensitive(const cJSON * const object, const char * const string);
CJSON_PUBLIC(cJSON_bool) cJSON_HasObjectItem(const cJSON *object, const char *string);
/* For analysing failed parses. This returns a pointer to the parse error. You'll probably need to look a few chars back to make sense of it. Defined when cJSON_Parse() returns 0. 0 when cJSON_Parse() succeeds. */
CJSON_PUBLIC(const char *) cJSON_GetErrorPtr(void);

/* Check item type and return its value */
CJSON_PUBLIC(char *) cJSON_GetStringValue(cJSON *item);
CJSON_PUBLIC(double) cJSON_GetNumberValue(cJSON *item);

/* These functions check the type of an item */
CJSON_PUBLIC(cJSON_bool) cJSON_IsInvalid(const cJSON * const item);
CJSON_PUBLIC(cJSON_bool) cJSON_IsFalse(const cJSON * const item);
CJSON_PUBLIC(cJSON_bool) cJSON_IsTrue(const cJSON * const item);
CJSON_PUBLIC(cJSON_bool) cJSON_IsBool(const cJSON * const item);
CJSON_PUBLIC(cJSON_bool) cJSON_IsNull(const cJSON * const item);
CJSON_PUBLIC(cJSON_bool) cJSON_IsNumber(const cJSON * const item);
CJSON_PUBLIC(cJSON_bool) cJSON_IsString(const cJSON * const item);
CJSON_PUBLIC(cJSON_bool) cJSON_IsArray(const cJSON * const item);
CJSON_PUBLIC(cJSON_bool) cJSON_IsObject(const cJSON * const item);
CJSON_PUBLIC(cJSON_bool) cJSON_IsRaw(const cJSON * const item);

/* These calls create a cJSON item of the appropriate type. */
CJSON_PUBLIC(cJSON *) cJSON_CreateNull(void);
CJSON_PUBLIC(cJSON *) cJSON_CreateTrue(void);
CJSON_PUBLIC(cJSON *) cJSON_CreateFalse(void);
CJSON_PUBLIC(cJSON *) cJSON_CreateBool(cJSON_bool boolean);
CJSON_PUBLIC(cJSON *) cJSON_CreateNumber(double num);
CJSON_PUBLIC(cJSON *) cJSON_CreateString(const char *string);
/* raw json */
CJSON_PUBLIC(cJSON *) cJSON_CreateRaw(const char *raw);
CJSON_PUBLIC(cJSON *) cJSON_CreateArray(void);
CJSON_PUBLIC(cJSON *) cJSON_CreateObject(void);

/* Create a string where valuestring references a string so
 * it will not be freed by cJSON_Delete */
CJSON_PUBLIC(cJSON *) cJSON_CreateStringReference(const char *string);
/* Create an object/array that only references it's elements so
 * they will not be freed by cJSON_Delete */
CJSON_PUBLIC(cJSON *) cJSON_CreateObjectReference(const cJSON *child);
CJSON_PUBLIC(cJSON *) cJSON_CreateArrayReference(const cJSON *child);

/* These utilities create an Array of count items.
 * The parameter count cannot be greater than the number of elements in the number array, otherwise array access will be out of bounds.*/
CJSON_PUBLIC(cJSON *) cJSON_CreateIntArray(const int *numbers, int count);
CJSON_PUBLIC(cJSON *) cJSON_CreateFloatArray(const float *numbers, int count);
CJSON_PUBLIC(cJSON *) cJSON_CreateDoubleArray(const double *numbers, int count);
CJSON_PUBLIC(cJSON *) cJSON_CreateStringArray(const char *const *strings, int count);

/* Append item to the specified array/object. */
CJSON_PUBLIC(cJSON_bool) cJSON_AddItemToArray(cJSON *array, cJSON *item);
CJSON_PUBLIC(cJSON_bool) cJSON_AddItemToObject(cJSON *object, const char *string, cJSON *item);
/* Use this when string is definitely const (i.e. a literal, or as good as), and will definitely survive the cJSON object.
 * WARNING: When this function was used, make sure to always check that (item->type & cJSON_StringIsConst) is zero before
 * writing to `item->string` */
CJSON_PUBLIC(cJSON_bool) cJSON_AddItemToObjectCS(cJSON *object, const char *string, cJSON *item);
/* Append reference to item to the specified array/object. Use this when you want to add an existing cJSON to a new cJSON, but don't want to corrupt your existing cJSON. */
CJSON_PUBLIC(cJSON_bool) cJSON_AddItemReferenceToArray(cJSON *array, cJSON *item);
CJSON_PUBLIC(cJSON_bool) cJSON_AddItemReferenceToObject(cJSON *object, const char *string, cJSON *item);

/* Remove/Detach items from Arrays/Objects. */
CJSON_PUBLIC(cJSON *) cJSON_DetachItemViaPointer(cJSON *parent, cJSON * const item);
CJSON_PUBLIC(cJSON *) cJSON_DetachItemFromArray(cJSON *array, int which);
CJSON_PUBLIC(void) cJSON_DeleteItemFromArray(cJSON *array, int which);
CJSON_PUBLIC(cJSON *) cJSON_DetachItemFromObject(cJSON *object, const char *string);
CJSON_PUBLIC(cJSON *) cJSON_DetachItemFromObjectCaseSensitive(cJSON *object, const char *string);
CJSON_PUBLIC(void) cJSON_DeleteItemFromObject(cJSON *object, const char *string);
CJSON_PUBLIC(void) cJSON_DeleteItemFromObjectCaseSensitive(cJSON *object, const char *string);

/* Update array items. */
CJSON_PUBLIC(cJSON_bool) cJSON_InsertItemInArray(cJSON *array, int which, cJSON *newitem); /* Shifts pre-existing items to the right. */
CJSON_PUBLIC(cJSON_bool) cJSON_ReplaceItemViaPointer(cJSON * const parent, cJSON * const item, cJSON * replacement);
CJSON_PUBLIC(cJSON_bool) cJSON_ReplaceItemInArray(cJSON *array, int which, cJSON *newitem);
CJSON_PUBLIC(cJSON_bool) cJSON_ReplaceItemInObject(cJSON *object,const char *string,cJSON *newitem);
CJSON_PUBLIC(cJSON_bool) cJSON_ReplaceItemInObjectCaseSensitive(cJSON *object,const char *string,cJSON *newitem);

/* Duplicate a cJSON item */
CJSON_PUBLIC(cJSON *) cJSON_Duplicate(const cJSON *item, cJSON_bool recurse);
/* Duplicate will create a new, identical cJSON item to the one you pass, in new memory that will
 * need to be released. With recurse!=0, it will duplicate any children connected to the item.
 * The item->next and ->prev pointers are always zero on return from Duplicate. */
/* Recursively compare two cJSON items for equality. If either a or b is NULL or invalid, they will be considered unequal.
 * case_sensitive determines if object keys are treated case sensitive (1) or case insensitive (0) */
CJSON_PUBLIC(cJSON_bool) cJSON_Compare(const cJSON * const a, const cJSON * const b, const cJSON_bool case_sensitive);

/* Minify a strings, remove blank characters(such as ' ', '\t', '\r', '\n') from strings.
 * The input pointer json cannot point to a read-only address area, such as a string constant, 
 * but should point to a readable and writable adress area. */
CJSON_PUBLIC(void) cJSON_Minify(char *json);

/* Helper functions for creating and adding items to an object at the same time.
 * They return the added item or NULL on failure. */
CJSON_PUBLIC(cJSON*) cJSON_AddNullToObject(cJSON * const object, const char * const name);
CJSON_PUBLIC(cJSON*) cJSON_AddTrueToObject(cJSON * const object, const char * const name);
CJSON_PUBLIC(cJSON*) cJSON_AddFalseToObject(cJSON * const object, const char * const name);
CJSON_PUBLIC(cJSON*) cJSON_AddBoolToObject(cJSON * const object, const char * const name, const cJSON_bool boolean);
CJSON_PUBLIC(cJSON*) cJSON_AddNumberToObject(cJSON * const object, const char * const name, const double number);
CJSON_PUBLIC(cJSON*) cJSON_AddStringToObject(cJSON * const object, const char * const name, const char * const string);
CJSON_PUBLIC(cJSON*) cJSON_AddRawToObject(cJSON * const object, const char * const name, const char * const raw);
CJSON_PUBLIC(cJSON*) cJSON_AddObjectToObject(cJSON * const object, const char * const name);
CJSON_PUBLIC(cJSON*) cJSON_AddArrayToObject(cJSON * const object, const char * const name);

/* When assigning an integer value, it needs to be propagated to valuedouble too. */
#define cJSON_SetIntValue(object, number) ((object) ? (object)->valueint = (object)->valuedouble = (number) : (number))
/* helper for the cJSON_SetNumberValue macro */
CJSON_PUBLIC(double) cJSON_SetNumberHelper(cJSON *object, double number);
#define cJSON_SetNumberValue(object, number) ((object != NULL) ? cJSON_SetNumberHelper(object, (double)number) : (number))
/* Change the valuestring of a cJSON_String object, only takes effect when type of object is cJSON_String */
CJSON_PUBLIC(char*) cJSON_SetValuestring(cJSON *object, const char *valuestring);

/* Macro for iterating over an array or object */
#define cJSON_ArrayForEach(element, array) for(element = (array != NULL) ? (array)->child : NULL; element != NULL; element = element->next)

/* malloc/free objects using the malloc/free functions that have been set with cJSON_InitHooks */
CJSON_PUBLIC(void *) cJSON_malloc(size_t size);
CJSON_PUBLIC(void) cJSON_free(void *object);

#ifdef __cplusplus
}
#endif

#endif

cJSON.c

/*
  Copyright (c) 2009-2017 Dave Gamble and cJSON contributors

  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:

  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  THE SOFTWARE.
*/

/* cJSON */
/* JSON parser in C. */

/* disable warnings about old C89 functions in MSVC */
#if !defined(_CRT_SECURE_NO_DEPRECATE) && defined(_MSC_VER)
#define _CRT_SECURE_NO_DEPRECATE
#endif

#ifdef __GNUC__
#pragma GCC visibility push(default)
#endif
#if defined(_MSC_VER)
#pragma warning (push)
/* disable warning about single line comments in system headers */
#pragma warning (disable : 4001)
#endif

#include <string.h>
#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <limits.h>
#include <ctype.h>
#include <float.h>

#ifdef ENABLE_LOCALES
#include <locale.h>
#endif

#if defined(_MSC_VER)
#pragma warning (pop)
#endif
#ifdef __GNUC__
#pragma GCC visibility pop
#endif

#include "cJSON.h"

/* define our own boolean type */
#ifdef true
#undef true
#endif
#define true ((cJSON_bool)1)

#ifdef false
#undef false
#endif
#define false ((cJSON_bool)0)

/* define isnan and isinf for ANSI C, if in C99 or above, isnan and isinf has been defined in math.h */
#ifndef isinf
#define isinf(d) (isnan((d - d)) && !isnan(d))
#endif
#ifndef isnan
#define isnan(d) (d != d)
#endif

#ifndef NAN
#define NAN 0.0/0.0
#endif

typedef struct {
    const unsigned char *json;
    size_t position;
} error;
static error global_error = { NULL, 0 };

CJSON_PUBLIC(const char *) cJSON_GetErrorPtr(void)
{
    return (const char*) (global_error.json + global_error.position);
}

CJSON_PUBLIC(char *) cJSON_GetStringValue(cJSON *item) 
{
    if (!cJSON_IsString(item)) 
    {
        return NULL;
    }

    return item->valuestring;
}

CJSON_PUBLIC(double) cJSON_GetNumberValue(cJSON *item) 
{
    if (!cJSON_IsNumber(item)) 
    {
        return NAN;
    }

    return item->valuedouble;
}

/* This is a safeguard to prevent copy-pasters from using incompatible C and header files */
#if (CJSON_VERSION_MAJOR != 1) || (CJSON_VERSION_MINOR != 7) || (CJSON_VERSION_PATCH != 13)
    #error cJSON.h and cJSON.c have different versions. Make sure that both have the same.
#endif

CJSON_PUBLIC(const char*) cJSON_Version(void)
{
    static char version[15];
    sprintf(version, "%i.%i.%i", CJSON_VERSION_MAJOR, CJSON_VERSION_MINOR, CJSON_VERSION_PATCH);

    return version;
}

/* Case insensitive string comparison, doesn't consider two NULL pointers equal though */
static int case_insensitive_strcmp(const unsigned char *string1, const unsigned char *string2)
{
    if ((string1 == NULL) || (string2 == NULL))
    {
        return 1;
    }

    if (string1 == string2)
    {
        return 0;
    }

    for(; tolower(*string1) == tolower(*string2); (void)string1++, string2++)
    {
        if (*string1 == '\0')
        {
            return 0;
        }
    }

    return tolower(*string1) - tolower(*string2);
}

typedef struct internal_hooks
{
    void *(CJSON_CDECL *allocate)(size_t size);
    void (CJSON_CDECL *deallocate)(void *pointer);
    void *(CJSON_CDECL *reallocate)(void *pointer, size_t size);
} internal_hooks;

#if defined(_MSC_VER)
/* work around MSVC error C2322: '...' address of dllimport '...' is not static */
static void * CJSON_CDECL internal_malloc(size_t size)
{
    return malloc(size);
}
static void CJSON_CDECL internal_free(void *pointer)
{
    free(pointer);
}
static void * CJSON_CDECL internal_realloc(void *pointer, size_t size)
{
    return realloc(pointer, size);
}
#else
#define internal_malloc malloc
#define internal_free free
#define internal_realloc realloc
#endif

/* strlen of character literals resolved at compile time */
#define static_strlen(string_literal) (sizeof(string_literal) - sizeof(""))

static internal_hooks global_hooks = { internal_malloc, internal_free, internal_realloc };

static unsigned char* cJSON_strdup(const unsigned char* string, const internal_hooks * const hooks)
{
    size_t length = 0;
    unsigned char *copy = NULL;

    if (string == NULL)
    {
        return NULL;
    }

    length = strlen((const char*)string) + sizeof("");
    copy = (unsigned char*)hooks->allocate(length);
    if (copy == NULL)
    {
        return NULL;
    }
    memcpy(copy, string, length);

    return copy;
}

CJSON_PUBLIC(void) cJSON_InitHooks(cJSON_Hooks* hooks)
{
    if (hooks == NULL)
    {
        /* Reset hooks */
        global_hooks.allocate = malloc;
        global_hooks.deallocate = free;
        global_hooks.reallocate = realloc;
        return;
    }

    global_hooks.allocate = malloc;
    if (hooks->malloc_fn != NULL)
    {
        global_hooks.allocate = hooks->malloc_fn;
    }

    global_hooks.deallocate = free;
    if (hooks->free_fn != NULL)
    {
        global_hooks.deallocate = hooks->free_fn;
    }

    /* use realloc only if both free and malloc are used */
    global_hooks.reallocate = NULL;
    if ((global_hooks.allocate == malloc) && (global_hooks.deallocate == free))
    {
        global_hooks.reallocate = realloc;
    }
}

/* Internal constructor. */
static cJSON *cJSON_New_Item(const internal_hooks * const hooks)
{
    cJSON* node = (cJSON*)hooks->allocate(sizeof(cJSON));
    if (node)
    {
        memset(node, '\0', sizeof(cJSON));
    }

    return node;
}

/* Delete a cJSON structure. */
CJSON_PUBLIC(void) cJSON_Delete(cJSON *item)
{
    cJSON *next = NULL;
    while (item != NULL)
    {
        next = item->next;
        if (!(item->type & cJSON_IsReference) && (item->child != NULL))
        {
            cJSON_Delete(item->child);
        }
        if (!(item->type & cJSON_IsReference) && (item->valuestring != NULL))
        {
            global_hooks.deallocate(item->valuestring);
        }
        if (!(item->type & cJSON_StringIsConst) && (item->string != NULL))
        {
            global_hooks.deallocate(item->string);
        }
        global_hooks.deallocate(item);
        item = next;
    }
}

/* get the decimal point character of the current locale */
static unsigned char get_decimal_point(void)
{
#ifdef ENABLE_LOCALES
    struct lconv *lconv = localeconv();
    return (unsigned char) lconv->decimal_point[0];
#else
    return '.';
#endif
}

typedef struct
{
    const unsigned char *content;
    size_t length;
    size_t offset;
    size_t depth; /* How deeply nested (in arrays/objects) is the input at the current offset. */
    internal_hooks hooks;
} parse_buffer;

/* check if the given size is left to read in a given parse buffer (starting with 1) */
#define can_read(buffer, size) ((buffer != NULL) && (((buffer)->offset + size) <= (buffer)->length))
/* check if the buffer can be accessed at the given index (starting with 0) */
#define can_access_at_index(buffer, index) ((buffer != NULL) && (((buffer)->offset + index) < (buffer)->length))
#define cannot_access_at_index(buffer, index) (!can_access_at_index(buffer, index))
/* get a pointer to the buffer at the position */
#define buffer_at_offset(buffer) ((buffer)->content + (buffer)->offset)

/* Parse the input text to generate a number, and populate the result into item. */
static cJSON_bool parse_number(cJSON * const item, parse_buffer * const input_buffer)
{
    double number = 0;
    unsigned char *after_end = NULL;
    unsigned char number_c_string[64];
    unsigned char decimal_point = get_decimal_point();
    size_t i = 0;

    if ((input_buffer == NULL) || (input_buffer->content == NULL))
    {
        return false;
    }

    /* copy the number into a temporary buffer and replace '.' with the decimal point
     * of the current locale (for strtod)
     * This also takes care of '\0' not necessarily being available for marking the end of the input */
    for (i = 0; (i < (sizeof(number_c_string) - 1)) && can_access_at_index(input_buffer, i); i++)
    {
        switch (buffer_at_offset(input_buffer)[i])
        {
            case '0':
            case '1':
            case '2':
            case '3':
            case '4':
            case '5':
            case '6':
            case '7':
            case '8':
            case '9':
            case '+':
            case '-':
            case 'e':
            case 'E':
                number_c_string[i] = buffer_at_offset(input_buffer)[i];
                break;

            case '.':
                number_c_string[i] = decimal_point;
                break;

            default:
                goto loop_end;
        }
    }
loop_end:
    number_c_string[i] = '\0';

    number = strtod((const char*)number_c_string, (char**)&after_end);
    if (number_c_string == after_end)
    {
        return false; /* parse_error */
    }

    item->valuedouble = number;

    /* use saturation in case of overflow */
    if (number >= INT_MAX)
    {
        item->valueint = INT_MAX;
    }
    else if (number <= (double)INT_MIN)
    {
        item->valueint = INT_MIN;
    }
    else
    {
        item->valueint = (int)number;
    }

    item->type = cJSON_Number;

    input_buffer->offset += (size_t)(after_end - number_c_string);
    return true;
}

/* don't ask me, but the original cJSON_SetNumberValue returns an integer or double */
CJSON_PUBLIC(double) cJSON_SetNumberHelper(cJSON *object, double number)
{
    if (number >= INT_MAX)
    {
        object->valueint = INT_MAX;
    }
    else if (number <= (double)INT_MIN)
    {
        object->valueint = INT_MIN;
    }
    else
    {
        object->valueint = (int)number;
    }

    return object->valuedouble = number;
}

CJSON_PUBLIC(char*) cJSON_SetValuestring(cJSON *object, const char *valuestring)
{
    char *copy = NULL;
    /* if object's type is not cJSON_String or is cJSON_IsReference, it should not set valuestring */
    if (!(object->type & cJSON_String) || (object->type & cJSON_IsReference))
    {
        return NULL;
    }
    if (strlen(valuestring) <= strlen(object->valuestring))
    {
        strcpy(object->valuestring, valuestring);
        return object->valuestring;
    }
    copy = (char*) cJSON_strdup((const unsigned char*)valuestring, &global_hooks);
    if (copy == NULL)
    {
        return NULL;
    }
    if (object->valuestring != NULL)
    {
        cJSON_free(object->valuestring);
    }
    object->valuestring = copy;

    return copy;
}

typedef struct
{
    unsigned char *buffer;
    size_t length;
    size_t offset;
    size_t depth; /* current nesting depth (for formatted printing) */
    cJSON_bool noalloc;
    cJSON_bool format; /* is this print a formatted print */
    internal_hooks hooks;
} printbuffer;

/* realloc printbuffer if necessary to have at least "needed" bytes more */
static unsigned char* ensure(printbuffer * const p, size_t needed)
{
    unsigned char *newbuffer = NULL;
    size_t newsize = 0;

    if ((p == NULL) || (p->buffer == NULL))
    {
        return NULL;
    }

    if ((p->length > 0) && (p->offset >= p->length))
    {
        /* make sure that offset is valid */
        return NULL;
    }

    if (needed > INT_MAX)
    {
        /* sizes bigger than INT_MAX are currently not supported */
        return NULL;
    }

    needed += p->offset + 1;
    if (needed <= p->length)
    {
        return p->buffer + p->offset;
    }

    if (p->noalloc) {
        return NULL;
    }

    /* calculate new buffer size */
    if (needed > (INT_MAX / 2))
    {
        /* overflow of int, use INT_MAX if possible */
        if (needed <= INT_MAX)
        {
            newsize = INT_MAX;
        }
        else
        {
            return NULL;
        }
    }
    else
    {
        newsize = needed * 2;
    }

    if (p->hooks.reallocate != NULL)
    {
        /* reallocate with realloc if available */
        newbuffer = (unsigned char*)p->hooks.reallocate(p->buffer, newsize);
        if (newbuffer == NULL)
        {
            p->hooks.deallocate(p->buffer);
            p->length = 0;
            p->buffer = NULL;

            return NULL;
        }
    }
    else
    {
        /* otherwise reallocate manually */
        newbuffer = (unsigned char*)p->hooks.allocate(newsize);
        if (!newbuffer)
        {
            p->hooks.deallocate(p->buffer);
            p->length = 0;
            p->buffer = NULL;

            return NULL;
        }
        if (newbuffer)
        {
            memcpy(newbuffer, p->buffer, p->offset + 1);
        }
        p->hooks.deallocate(p->buffer);
    }
    p->length = newsize;
    p->buffer = newbuffer;

    return newbuffer + p->offset;
}

/* calculate the new length of the string in a printbuffer and update the offset */
static void update_offset(printbuffer * const buffer)
{
    const unsigned char *buffer_pointer = NULL;
    if ((buffer == NULL) || (buffer->buffer == NULL))
    {
        return;
    }
    buffer_pointer = buffer->buffer + buffer->offset;

    buffer->offset += strlen((const char*)buffer_pointer);
}

/* securely comparison of floating-point variables */
static cJSON_bool compare_double(double a, double b)
{
    double maxVal = fabs(a) > fabs(b) ? fabs(a) : fabs(b);
    return (fabs(a - b) <= maxVal * DBL_EPSILON);
}

/* Render the number nicely from the given item into a string. */
static cJSON_bool print_number(const cJSON * const item, printbuffer * const output_buffer)
{
    unsigned char *output_pointer = NULL;
    double d = item->valuedouble;
    int length = 0;
    size_t i = 0;
    unsigned char number_buffer[26] = {0}; /* temporary buffer to print the number into */
    unsigned char decimal_point = get_decimal_point();
    double test = 0.0;

    if (output_buffer == NULL)
    {
        return false;
    }

    /* This checks for NaN and Infinity */
    if (isnan(d) || isinf(d))
    {
        length = sprintf((char*)number_buffer, "null");
    }
    else
    {
        /* Try 15 decimal places of precision to avoid nonsignificant nonzero digits */
        length = sprintf((char*)number_buffer, "%1.15g", d);

        /* Check whether the original double can be recovered */
        if ((sscanf((char*)number_buffer, "%lg", &test) != 1) || !compare_double((double)test, d))
        {
            /* If not, print with 17 decimal places of precision */
            length = sprintf((char*)number_buffer, "%1.17g", d);
        }
    }

    /* sprintf failed or buffer overrun occurred */
    if ((length < 0) || (length > (int)(sizeof(number_buffer) - 1)))
    {
        return false;
    }

    /* reserve appropriate space in the output */
    output_pointer = ensure(output_buffer, (size_t)length + sizeof(""));
    if (output_pointer == NULL)
    {
        return false;
    }

    /* copy the printed number to the output and replace locale
     * dependent decimal point with '.' */
    for (i = 0; i < ((size_t)length); i++)
    {
        if (number_buffer[i] == decimal_point)
        {
            output_pointer[i] = '.';
            continue;
        }

        output_pointer[i] = number_buffer[i];
    }
    output_pointer[i] = '\0';

    output_buffer->offset += (size_t)length;

    return true;
}

/* parse 4 digit hexadecimal number */
static unsigned parse_hex4(const unsigned char * const input)
{
    unsigned int h = 0;
    size_t i = 0;

    for (i = 0; i < 4; i++)
    {
        /* parse digit */
        if ((input[i] >= '0') && (input[i] <= '9'))
        {
            h += (unsigned int) input[i] - '0';
        }
        else if ((input[i] >= 'A') && (input[i] <= 'F'))
        {
            h += (unsigned int) 10 + input[i] - 'A';
        }
        else if ((input[i] >= 'a') && (input[i] <= 'f'))
        {
            h += (unsigned int) 10 + input[i] - 'a';
        }
        else /* invalid */
        {
            return 0;
        }

        if (i < 3)
        {
            /* shift left to make place for the next nibble */
            h = h << 4;
        }
    }

    return h;
}

/* converts a UTF-16 literal to UTF-8
 * A literal can be one or two sequences of the form \uXXXX */
static unsigned char utf16_literal_to_utf8(const unsigned char * const input_pointer, const unsigned char * const input_end, unsigned char **output_pointer)
{
    long unsigned int codepoint = 0;
    unsigned int first_code = 0;
    const unsigned char *first_sequence = input_pointer;
    unsigned char utf8_length = 0;
    unsigned char utf8_position = 0;
    unsigned char sequence_length = 0;
    unsigned char first_byte_mark = 0;

    if ((input_end - first_sequence) < 6)
    {
        /* input ends unexpectedly */
        goto fail;
    }

    /* get the first utf16 sequence */
    first_code = parse_hex4(first_sequence + 2);

    /* check that the code is valid */
    if (((first_code >= 0xDC00) && (first_code <= 0xDFFF)))
    {
        goto fail;
    }

    /* UTF16 surrogate pair */
    if ((first_code >= 0xD800) && (first_code <= 0xDBFF))
    {
        const unsigned char *second_sequence = first_sequence + 6;
        unsigned int second_code = 0;
        sequence_length = 12; /* \uXXXX\uXXXX */

        if ((input_end - second_sequence) < 6)
        {
            /* input ends unexpectedly */
            goto fail;
        }

        if ((second_sequence[0] != '\\') || (second_sequence[1] != 'u'))
        {
            /* missing second half of the surrogate pair */
            goto fail;
        }

        /* get the second utf16 sequence */
        second_code = parse_hex4(second_sequence + 2);
        /* check that the code is valid */
        if ((second_code < 0xDC00) || (second_code > 0xDFFF))
        {
            /* invalid second half of the surrogate pair */
            goto fail;
        }


        /* calculate the unicode codepoint from the surrogate pair */
        codepoint = 0x10000 + (((first_code & 0x3FF) << 10) | (second_code & 0x3FF));
    }
    else
    {
        sequence_length = 6; /* \uXXXX */
        codepoint = first_code;
    }

    /* encode as UTF-8
     * takes at maximum 4 bytes to encode:
     * 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */
    if (codepoint < 0x80)
    {
        /* normal ascii, encoding 0xxxxxxx */
        utf8_length = 1;
    }
    else if (codepoint < 0x800)
    {
        /* two bytes, encoding 110xxxxx 10xxxxxx */
        utf8_length = 2;
        first_byte_mark = 0xC0; /* 11000000 */
    }
    else if (codepoint < 0x10000)
    {
        /* three bytes, encoding 1110xxxx 10xxxxxx 10xxxxxx */
        utf8_length = 3;
        first_byte_mark = 0xE0; /* 11100000 */
    }
    else if (codepoint <= 0x10FFFF)
    {
        /* four bytes, encoding 1110xxxx 10xxxxxx 10xxxxxx 10xxxxxx */
        utf8_length = 4;
        first_byte_mark = 0xF0; /* 11110000 */
    }
    else
    {
        /* invalid unicode codepoint */
        goto fail;
    }

    /* encode as utf8 */
    for (utf8_position = (unsigned char)(utf8_length - 1); utf8_position > 0; utf8_position--)
    {
        /* 10xxxxxx */
        (*output_pointer)[utf8_position] = (unsigned char)((codepoint | 0x80) & 0xBF);
        codepoint >>= 6;
    }
    /* encode first byte */
    if (utf8_length > 1)
    {
        (*output_pointer)[0] = (unsigned char)((codepoint | first_byte_mark) & 0xFF);
    }
    else
    {
        (*output_pointer)[0] = (unsigned char)(codepoint & 0x7F);
    }

    *output_pointer += utf8_length;

    return sequence_length;

fail:
    return 0;
}

/* Parse the input text into an unescaped cinput, and populate item. */
static cJSON_bool parse_string(cJSON * const item, parse_buffer * const input_buffer)
{
    const unsigned char *input_pointer = buffer_at_offset(input_buffer) + 1;
    const unsigned char *input_end = buffer_at_offset(input_buffer) + 1;
    unsigned char *output_pointer = NULL;
    unsigned char *output = NULL;

    /* not a string */
    if (buffer_at_offset(input_buffer)[0] != '\"')
    {
        goto fail;
    }

    {
        /* calculate approximate size of the output (overestimate) */
        size_t allocation_length = 0;
        size_t skipped_bytes = 0;
        while (((size_t)(input_end - input_buffer->content) < input_buffer->length) && (*input_end != '\"'))
        {
            /* is escape sequence */
            if (input_end[0] == '\\')
            {
                if ((size_t)(input_end + 1 - input_buffer->content) >= input_buffer->length)
                {
                    /* prevent buffer overflow when last input character is a backslash */
                    goto fail;
                }
                skipped_bytes++;
                input_end++;
            }
            input_end++;
        }
        if (((size_t)(input_end - input_buffer->content) >= input_buffer->length) || (*input_end != '\"'))
        {
            goto fail; /* string ended unexpectedly */
        }

        /* This is at most how much we need for the output */
        allocation_length = (size_t) (input_end - buffer_at_offset(input_buffer)) - skipped_bytes;
        output = (unsigned char*)input_buffer->hooks.allocate(allocation_length + sizeof(""));
        if (output == NULL)
        {
            goto fail; /* allocation failure */
        }
    }

    output_pointer = output;
    /* loop through the string literal */
    while (input_pointer < input_end)
    {
        if (*input_pointer != '\\')
        {
            *output_pointer++ = *input_pointer++;
        }
        /* escape sequence */
        else
        {
            unsigned char sequence_length = 2;
            if ((input_end - input_pointer) < 1)
            {
                goto fail;
            }

            switch (input_pointer[1])
            {
                case 'b':
                    *output_pointer++ = '\b';
                    break;
                case 'f':
                    *output_pointer++ = '\f';
                    break;
                case 'n':
                    *output_pointer++ = '\n';
                    break;
                case 'r':
                    *output_pointer++ = '\r';
                    break;
                case 't':
                    *output_pointer++ = '\t';
                    break;
                case '\"':
                case '\\':
                case '/':
                    *output_pointer++ = input_pointer[1];
                    break;

                /* UTF-16 literal */
                case 'u':
                    sequence_length = utf16_literal_to_utf8(input_pointer, input_end, &output_pointer);
                    if (sequence_length == 0)
                    {
                        /* failed to convert UTF16-literal to UTF-8 */
                        goto fail;
                    }
                    break;

                default:
                    goto fail;
            }
            input_pointer += sequence_length;
        }
    }

    /* zero terminate the output */
    *output_pointer = '\0';

    item->type = cJSON_String;
    item->valuestring = (char*)output;

    input_buffer->offset = (size_t) (input_end - input_buffer->content);
    input_buffer->offset++;

    return true;

fail:
    if (output != NULL)
    {
        input_buffer->hooks.deallocate(output);
    }

    if (input_pointer != NULL)
    {
        input_buffer->offset = (size_t)(input_pointer - input_buffer->content);
    }

    return false;
}

/* Render the cstring provided to an escaped version that can be printed. */
static cJSON_bool print_string_ptr(const unsigned char * const input, printbuffer * const output_buffer)
{
    const unsigned char *input_pointer = NULL;
    unsigned char *output = NULL;
    unsigned char *output_pointer = NULL;
    size_t output_length = 0;
    /* numbers of additional characters needed for escaping */
    size_t escape_characters = 0;

    if (output_buffer == NULL)
    {
        return false;
    }

    /* empty string */
    if (input == NULL)
    {
        output = ensure(output_buffer, sizeof("\"\""));
        if (output == NULL)
        {
            return false;
        }
        strcpy((char*)output, "\"\"");

        return true;
    }

    /* set "flag" to 1 if something needs to be escaped */
    for (input_pointer = input; *input_pointer; input_pointer++)
    {
        switch (*input_pointer)
        {
            case '\"':
            case '\\':
            case '\b':
            case '\f':
            case '\n':
            case '\r':
            case '\t':
                /* one character escape sequence */
                escape_characters++;
                break;
            default:
                if (*input_pointer < 32)
                {
                    /* UTF-16 escape sequence uXXXX */
                    escape_characters += 5;
                }
                break;
        }
    }
    output_length = (size_t)(input_pointer - input) + escape_characters;

    output = ensure(output_buffer, output_length + sizeof("\"\""));
    if (output == NULL)
    {
        return false;
    }

    /* no characters have to be escaped */
    if (escape_characters == 0)
    {
        output[0] = '\"';
        memcpy(output + 1, input, output_length);
        output[output_length + 1] = '\"';
        output[output_length + 2] = '\0';

        return true;
    }

    output[0] = '\"';
    output_pointer = output + 1;
    /* copy the string */
    for (input_pointer = input; *input_pointer != '\0'; (void)input_pointer++, output_pointer++)
    {
        if ((*input_pointer > 31) && (*input_pointer != '\"') && (*input_pointer != '\\'))
        {
            /* normal character, copy */
            *output_pointer = *input_pointer;
        }
        else
        {
            /* character needs to be escaped */
            *output_pointer++ = '\\';
            switch (*input_pointer)
            {
                case '\\':
                    *output_pointer = '\\';
                    break;
                case '\"':
                    *output_pointer = '\"';
                    break;
                case '\b':
                    *output_pointer = 'b';
                    break;
                case '\f':
                    *output_pointer = 'f';
                    break;
                case '\n':
                    *output_pointer = 'n';
                    break;
                case '\r':
                    *output_pointer = 'r';
                    break;
                case '\t':
                    *output_pointer = 't';
                    break;
                default:
                    /* escape and print as unicode codepoint */
                    sprintf((char*)output_pointer, "u%04x", *input_pointer);
                    output_pointer += 4;
                    break;
            }
        }
    }
    output[output_length + 1] = '\"';
    output[output_length + 2] = '\0';

    return true;
}

/* Invoke print_string_ptr (which is useful) on an item. */
static cJSON_bool print_string(const cJSON * const item, printbuffer * const p)
{
    return print_string_ptr((unsigned char*)item->valuestring, p);
}

/* Predeclare these prototypes. */
static cJSON_bool parse_value(cJSON * const item, parse_buffer * const input_buffer);
static cJSON_bool print_value(const cJSON * const item, printbuffer * const output_buffer);
static cJSON_bool parse_array(cJSON * const item, parse_buffer * const input_buffer);
static cJSON_bool print_array(const cJSON * const item, printbuffer * const output_buffer);
static cJSON_bool parse_object(cJSON * const item, parse_buffer * const input_buffer);
static cJSON_bool print_object(const cJSON * const item, printbuffer * const output_buffer);

/* Utility to jump whitespace and cr/lf */
static parse_buffer *buffer_skip_whitespace(parse_buffer * const buffer)
{
    if ((buffer == NULL) || (buffer->content == NULL))
    {
        return NULL;
    }

    if (cannot_access_at_index(buffer, 0))
    {
        return buffer;
    }

    while (can_access_at_index(buffer, 0) && (buffer_at_offset(buffer)[0] <= 32))
    {
       buffer->offset++;
    }

    if (buffer->offset == buffer->length)
    {
        buffer->offset--;
    }

    return buffer;
}

/* skip the UTF-8 BOM (byte order mark) if it is at the beginning of a buffer */
static parse_buffer *skip_utf8_bom(parse_buffer * const buffer)
{
    if ((buffer == NULL) || (buffer->content == NULL) || (buffer->offset != 0))
    {
        return NULL;
    }

    if (can_access_at_index(buffer, 4) && (strncmp((const char*)buffer_at_offset(buffer), "\xEF\xBB\xBF", 3) == 0))
    {
        buffer->offset += 3;
    }

    return buffer;
}

CJSON_PUBLIC(cJSON *) cJSON_ParseWithOpts(const char *value, const char **return_parse_end, cJSON_bool require_null_terminated)
{
    size_t buffer_length;

    if (NULL == value)
    {
        return NULL;
    }

    /* Adding null character size due to require_null_terminated. */
    buffer_length = strlen(value) + sizeof("");

    return cJSON_ParseWithLengthOpts(value, buffer_length, return_parse_end, require_null_terminated);
}

/* Parse an object - create a new root, and populate. */
CJSON_PUBLIC(cJSON *) cJSON_ParseWithLengthOpts(const char *value, size_t buffer_length, const char **return_parse_end, cJSON_bool require_null_terminated)
{
    parse_buffer buffer = { 0, 0, 0, 0, { 0, 0, 0 } };
    cJSON *item = NULL;

    /* reset error position */
    global_error.json = NULL;
    global_error.position = 0;

    if (value == NULL || 0 == buffer_length)
    {
        goto fail;
    }

    buffer.content = (const unsigned char*)value;
    buffer.length = buffer_length; 
    buffer.offset = 0;
    buffer.hooks = global_hooks;

    item = cJSON_New_Item(&global_hooks);
    if (item == NULL) /* memory fail */
    {
        goto fail;
    }

    if (!parse_value(item, buffer_skip_whitespace(skip_utf8_bom(&buffer))))
    {
        /* parse failure. ep is set. */
        goto fail;
    }

    /* if we require null-terminated JSON without appended garbage, skip and then check for a null terminator */
    if (require_null_terminated)
    {
        buffer_skip_whitespace(&buffer);
        if ((buffer.offset >= buffer.length) || buffer_at_offset(&buffer)[0] != '\0')
        {
            goto fail;
        }
    }
    if (return_parse_end)
    {
        *return_parse_end = (const char*)buffer_at_offset(&buffer);
    }

    return item;

fail:
    if (item != NULL)
    {
        cJSON_Delete(item);
    }

    if (value != NULL)
    {
        error local_error;
        local_error.json = (const unsigned char*)value;
        local_error.position = 0;

        if (buffer.offset < buffer.length)
        {
            local_error.position = buffer.offset;
        }
        else if (buffer.length > 0)
        {
            local_error.position = buffer.length - 1;
        }

        if (return_parse_end != NULL)
        {
            *return_parse_end = (const char*)local_error.json + local_error.position;
        }

        global_error = local_error;
    }

    return NULL;
}

/* Default options for cJSON_Parse */
CJSON_PUBLIC(cJSON *) cJSON_Parse(const char *value)
{
    return cJSON_ParseWithOpts(value, 0, 0);
}

CJSON_PUBLIC(cJSON *) cJSON_ParseWithLength(const char *value, size_t buffer_length)
{
    return cJSON_ParseWithLengthOpts(value, buffer_length, 0, 0);
}

#define cjson_min(a, b) (((a) < (b)) ? (a) : (b))

static unsigned char *print(const cJSON * const item, cJSON_bool format, const internal_hooks * const hooks)
{
    static const size_t default_buffer_size = 256;
    printbuffer buffer[1];
    unsigned char *printed = NULL;

    memset(buffer, 0, sizeof(buffer));

    /* create buffer */
    buffer->buffer = (unsigned char*) hooks->allocate(default_buffer_size);
    buffer->length = default_buffer_size;
    buffer->format = format;
    buffer->hooks = *hooks;
    if (buffer->buffer == NULL)
    {
        goto fail;
    }

    /* print the value */
    if (!print_value(item, buffer))
    {
        goto fail;
    }
    update_offset(buffer);

    /* check if reallocate is available */
    if (hooks->reallocate != NULL)
    {
        printed = (unsigned char*) hooks->reallocate(buffer->buffer, buffer->offset + 1);
        if (printed == NULL) {
            goto fail;
        }
        buffer->buffer = NULL;
    }
    else /* otherwise copy the JSON over to a new buffer */
    {
        printed = (unsigned char*) hooks->allocate(buffer->offset + 1);
        if (printed == NULL)
        {
            goto fail;
        }
        memcpy(printed, buffer->buffer, cjson_min(buffer->length, buffer->offset + 1));
        printed[buffer->offset] = '\0'; /* just to be sure */

        /* free the buffer */
        hooks->deallocate(buffer->buffer);
    }

    return printed;

fail:
    if (buffer->buffer != NULL)
    {
        hooks->deallocate(buffer->buffer);
    }

    if (printed != NULL)
    {
        hooks->deallocate(printed);
    }

    return NULL;
}

/* Render a cJSON item/entity/structure to text. */
CJSON_PUBLIC(char *) cJSON_Print(const cJSON *item)
{
    return (char*)print(item, true, &global_hooks);
}

CJSON_PUBLIC(char *) cJSON_PrintUnformatted(const cJSON *item)
{
    return (char*)print(item, false, &global_hooks);
}

CJSON_PUBLIC(char *) cJSON_PrintBuffered(const cJSON *item, int prebuffer, cJSON_bool fmt)
{
    printbuffer p = { 0, 0, 0, 0, 0, 0, { 0, 0, 0 } };

    if (prebuffer < 0)
    {
        return NULL;
    }

    p.buffer = (unsigned char*)global_hooks.allocate((size_t)prebuffer);
    if (!p.buffer)
    {
        return NULL;
    }

    p.length = (size_t)prebuffer;
    p.offset = 0;
    p.noalloc = false;
    p.format = fmt;
    p.hooks = global_hooks;

    if (!print_value(item, &p))
    {
        global_hooks.deallocate(p.buffer);
        return NULL;
    }

    return (char*)p.buffer;
}

CJSON_PUBLIC(cJSON_bool) cJSON_PrintPreallocated(cJSON *item, char *buffer, const int length, const cJSON_bool format)
{
    printbuffer p = { 0, 0, 0, 0, 0, 0, { 0, 0, 0 } };

    if ((length < 0) || (buffer == NULL))
    {
        return false;
    }

    p.buffer = (unsigned char*)buffer;
    p.length = (size_t)length;
    p.offset = 0;
    p.noalloc = true;
    p.format = format;
    p.hooks = global_hooks;

    return print_value(item, &p);
}

/* Parser core - when encountering text, process appropriately. */
static cJSON_bool parse_value(cJSON * const item, parse_buffer * const input_buffer)
{
    if ((input_buffer == NULL) || (input_buffer->content == NULL))
    {
        return false; /* no input */
    }

    /* parse the different types of values */
    /* null */
    if (can_read(input_buffer, 4) && (strncmp((const char*)buffer_at_offset(input_buffer), "null", 4) == 0))
    {
        item->type = cJSON_NULL;
        input_buffer->offset += 4;
        return true;
    }
    /* false */
    if (can_read(input_buffer, 5) && (strncmp((const char*)buffer_at_offset(input_buffer), "false", 5) == 0))
    {
        item->type = cJSON_False;
        input_buffer->offset += 5;
        return true;
    }
    /* true */
    if (can_read(input_buffer, 4) && (strncmp((const char*)buffer_at_offset(input_buffer), "true", 4) == 0))
    {
        item->type = cJSON_True;
        item->valueint = 1;
        input_buffer->offset += 4;
        return true;
    }
    /* string */
    if (can_access_at_index(input_buffer, 0) && (buffer_at_offset(input_buffer)[0] == '\"'))
    {
        return parse_string(item, input_buffer);
    }
    /* number */
    if (can_access_at_index(input_buffer, 0) && ((buffer_at_offset(input_buffer)[0] == '-') || ((buffer_at_offset(input_buffer)[0] >= '0') && (buffer_at_offset(input_buffer)[0] <= '9'))))
    {
        return parse_number(item, input_buffer);
    }
    /* array */
    if (can_access_at_index(input_buffer, 0) && (buffer_at_offset(input_buffer)[0] == '['))
    {
        return parse_array(item, input_buffer);
    }
    /* object */
    if (can_access_at_index(input_buffer, 0) && (buffer_at_offset(input_buffer)[0] == '{'))
    {
        return parse_object(item, input_buffer);
    }

    return false;
}

/* Render a value to text. */
static cJSON_bool print_value(const cJSON * const item, printbuffer * const output_buffer)
{
    unsigned char *output = NULL;

    if ((item == NULL) || (output_buffer == NULL))
    {
        return false;
    }

    switch ((item->type) & 0xFF)
    {
        case cJSON_NULL:
            output = ensure(output_buffer, 5);
            if (output == NULL)
            {
                return false;
            }
            strcpy((char*)output, "null");
            return true;

        case cJSON_False:
            output = ensure(output_buffer, 6);
            if (output == NULL)
            {
                return false;
            }
            strcpy((char*)output, "false");
            return true;

        case cJSON_True:
            output = ensure(output_buffer, 5);
            if (output == NULL)
            {
                return false;
            }
            strcpy((char*)output, "true");
            return true;

        case cJSON_Number:
            return print_number(item, output_buffer);

        case cJSON_Raw:
        {
            size_t raw_length = 0;
            if (item->valuestring == NULL)
            {
                return false;
            }

            raw_length = strlen(item->valuestring) + sizeof("");
            output = ensure(output_buffer, raw_length);
            if (output == NULL)
            {
                return false;
            }
            memcpy(output, item->valuestring, raw_length);
            return true;
        }

        case cJSON_String:
            return print_string(item, output_buffer);

        case cJSON_Array:
            return print_array(item, output_buffer);

        case cJSON_Object:
            return print_object(item, output_buffer);

        default:
            return false;
    }
}

/* Build an array from input text. */
static cJSON_bool parse_array(cJSON * const item, parse_buffer * const input_buffer)
{
    cJSON *head = NULL; /* head of the linked list */
    cJSON *current_item = NULL;

    if (input_buffer->depth >= CJSON_NESTING_LIMIT)
    {
        return false; /* to deeply nested */
    }
    input_buffer->depth++;

    if (buffer_at_offset(input_buffer)[0] != '[')
    {
        /* not an array */
        goto fail;
    }

    input_buffer->offset++;
    buffer_skip_whitespace(input_buffer);
    if (can_access_at_index(input_buffer, 0) && (buffer_at_offset(input_buffer)[0] == ']'))
    {
        /* empty array */
        goto success;
    }

    /* check if we skipped to the end of the buffer */
    if (cannot_access_at_index(input_buffer, 0))
    {
        input_buffer->offset--;
        goto fail;
    }

    /* step back to character in front of the first element */
    input_buffer->offset--;
    /* loop through the comma separated array elements */
    do
    {
        /* allocate next item */
        cJSON *new_item = cJSON_New_Item(&(input_buffer->hooks));
        if (new_item == NULL)
        {
            goto fail; /* allocation failure */
        }

        /* attach next item to list */
        if (head == NULL)
        {
            /* start the linked list */
            current_item = head = new_item;
        }
        else
        {
            /* add to the end and advance */
            current_item->next = new_item;
            new_item->prev = current_item;
            current_item = new_item;
        }

        /* parse next value */
        input_buffer->offset++;
        buffer_skip_whitespace(input_buffer);
        if (!parse_value(current_item, input_buffer))
        {
            goto fail; /* failed to parse value */
        }
        buffer_skip_whitespace(input_buffer);
    }
    while (can_access_at_index(input_buffer, 0) && (buffer_at_offset(input_buffer)[0] == ','));

    if (cannot_access_at_index(input_buffer, 0) || buffer_at_offset(input_buffer)[0] != ']')
    {
        goto fail; /* expected end of array */
    }

success:
    input_buffer->depth--;

    item->type = cJSON_Array;
    item->child = head;

    input_buffer->offset++;

    return true;

fail:
    if (head != NULL)
    {
        cJSON_Delete(head);
    }

    return false;
}

/* Render an array to text */
static cJSON_bool print_array(const cJSON * const item, printbuffer * const output_buffer)
{
    unsigned char *output_pointer = NULL;
    size_t length = 0;
    cJSON *current_element = item->child;

    if (output_buffer == NULL)
    {
        return false;
    }

    /* Compose the output array. */
    /* opening square bracket */
    output_pointer = ensure(output_buffer, 1);
    if (output_pointer == NULL)
    {
        return false;
    }

    *output_pointer = '[';
    output_buffer->offset++;
    output_buffer->depth++;

    while (current_element != NULL)
    {
        if (!print_value(current_element, output_buffer))
        {
            return false;
        }
        update_offset(output_buffer);
        if (current_element->next)
        {
            length = (size_t) (output_buffer->format ? 2 : 1);
            output_pointer = ensure(output_buffer, length + 1);
            if (output_pointer == NULL)
            {
                return false;
            }
            *output_pointer++ = ',';
            if(output_buffer->format)
            {
                *output_pointer++ = ' ';
            }
            *output_pointer = '\0';
            output_buffer->offset += length;
        }
        current_element = current_element->next;
    }

    output_pointer = ensure(output_buffer, 2);
    if (output_pointer == NULL)
    {
        return false;
    }
    *output_pointer++ = ']';
    *output_pointer = '\0';
    output_buffer->depth--;

    return true;
}

/* Build an object from the text. */
static cJSON_bool parse_object(cJSON * const item, parse_buffer * const input_buffer)
{
    cJSON *head = NULL; /* linked list head */
    cJSON *current_item = NULL;

    if (input_buffer->depth >= CJSON_NESTING_LIMIT)
    {
        return false; /* to deeply nested */
    }
    input_buffer->depth++;

    if (cannot_access_at_index(input_buffer, 0) || (buffer_at_offset(input_buffer)[0] != '{'))
    {
        goto fail; /* not an object */
    }

    input_buffer->offset++;
    buffer_skip_whitespace(input_buffer);
    if (can_access_at_index(input_buffer, 0) && (buffer_at_offset(input_buffer)[0] == '}'))
    {
        goto success; /* empty object */
    }

    /* check if we skipped to the end of the buffer */
    if (cannot_access_at_index(input_buffer, 0))
    {
        input_buffer->offset--;
        goto fail;
    }

    /* step back to character in front of the first element */
    input_buffer->offset--;
    /* loop through the comma separated array elements */
    do
    {
        /* allocate next item */
        cJSON *new_item = cJSON_New_Item(&(input_buffer->hooks));
        if (new_item == NULL)
        {
            goto fail; /* allocation failure */
        }

        /* attach next item to list */
        if (head == NULL)
        {
            /* start the linked list */
            current_item = head = new_item;
        }
        else
        {
            /* add to the end and advance */
            current_item->next = new_item;
            new_item->prev = current_item;
            current_item = new_item;
        }

        /* parse the name of the child */
        input_buffer->offset++;
        buffer_skip_whitespace(input_buffer);
        if (!parse_string(current_item, input_buffer))
        {
            goto fail; /* failed to parse name */
        }
        buffer_skip_whitespace(input_buffer);

        /* swap valuestring and string, because we parsed the name */
        current_item->string = current_item->valuestring;
        current_item->valuestring = NULL;

        if (cannot_access_at_index(input_buffer, 0) || (buffer_at_offset(input_buffer)[0] != ':'))
        {
            goto fail; /* invalid object */
        }

        /* parse the value */
        input_buffer->offset++;
        buffer_skip_whitespace(input_buffer);
        if (!parse_value(current_item, input_buffer))
        {
            goto fail; /* failed to parse value */
        }
        buffer_skip_whitespace(input_buffer);
    }
    while (can_access_at_index(input_buffer, 0) && (buffer_at_offset(input_buffer)[0] == ','));

    if (cannot_access_at_index(input_buffer, 0) || (buffer_at_offset(input_buffer)[0] != '}'))
    {
        goto fail; /* expected end of object */
    }

success:
    input_buffer->depth--;

    item->type = cJSON_Object;
    item->child = head;

    input_buffer->offset++;
    return true;

fail:
    if (head != NULL)
    {
        cJSON_Delete(head);
    }

    return false;
}

/* Render an object to text. */
static cJSON_bool print_object(const cJSON * const item, printbuffer * const output_buffer)
{
    unsigned char *output_pointer = NULL;
    size_t length = 0;
    cJSON *current_item = item->child;

    if (output_buffer == NULL)
    {
        return false;
    }

    /* Compose the output: */
    length = (size_t) (output_buffer->format ? 2 : 1); /* fmt: {\n */
    output_pointer = ensure(output_buffer, length + 1);
    if (output_pointer == NULL)
    {
        return false;
    }

    *output_pointer++ = '{';
    output_buffer->depth++;
    if (output_buffer->format)
    {
        *output_pointer++ = '\n';
    }
    output_buffer->offset += length;

    while (current_item)
    {
        if (output_buffer->format)
        {
            size_t i;
            output_pointer = ensure(output_buffer, output_buffer->depth);
            if (output_pointer == NULL)
            {
                return false;
            }
            for (i = 0; i < output_buffer->depth; i++)
            {
                *output_pointer++ = '\t';
            }
            output_buffer->offset += output_buffer->depth;
        }

        /* print key */
        if (!print_string_ptr((unsigned char*)current_item->string, output_buffer))
        {
            return false;
        }
        update_offset(output_buffer);

        length = (size_t) (output_buffer->format ? 2 : 1);
        output_pointer = ensure(output_buffer, length);
        if (output_pointer == NULL)
        {
            return false;
        }
        *output_pointer++ = ':';
        if (output_buffer->format)
        {
            *output_pointer++ = '\t';
        }
        output_buffer->offset += length;

        /* print value */
        if (!print_value(current_item, output_buffer))
        {
            return false;
        }
        update_offset(output_buffer);

        /* print comma if not last */
        length = ((size_t)(output_buffer->format ? 1 : 0) + (size_t)(current_item->next ? 1 : 0));
        output_pointer = ensure(output_buffer, length + 1);
        if (output_pointer == NULL)
        {
            return false;
        }
        if (current_item->next)
        {
            *output_pointer++ = ',';
        }

        if (output_buffer->format)
        {
            *output_pointer++ = '\n';
        }
        *output_pointer = '\0';
        output_buffer->offset += length;

        current_item = current_item->next;
    }

    output_pointer = ensure(output_buffer, output_buffer->format ? (output_buffer->depth + 1) : 2);
    if (output_pointer == NULL)
    {
        return false;
    }
    if (output_buffer->format)
    {
        size_t i;
        for (i = 0; i < (output_buffer->depth - 1); i++)
        {
            *output_pointer++ = '\t';
        }
    }
    *output_pointer++ = '}';
    *output_pointer = '\0';
    output_buffer->depth--;

    return true;
}

/* Get Array size/item / object item. */
CJSON_PUBLIC(int) cJSON_GetArraySize(const cJSON *array)
{
    cJSON *child = NULL;
    size_t size = 0;

    if (array == NULL)
    {
        return 0;
    }

    child = array->child;

    while(child != NULL)
    {
        size++;
        child = child->next;
    }

    /* FIXME: Can overflow here. Cannot be fixed without breaking the API */

    return (int)size;
}

static cJSON* get_array_item(const cJSON *array, size_t index)
{
    cJSON *current_child = NULL;

    if (array == NULL)
    {
        return NULL;
    }

    current_child = array->child;
    while ((current_child != NULL) && (index > 0))
    {
        index--;
        current_child = current_child->next;
    }

    return current_child;
}

CJSON_PUBLIC(cJSON *) cJSON_GetArrayItem(const cJSON *array, int index)
{
    if (index < 0)
    {
        return NULL;
    }

    return get_array_item(array, (size_t)index);
}

static cJSON *get_object_item(const cJSON * const object, const char * const name, const cJSON_bool case_sensitive)
{
    cJSON *current_element = NULL;

    if ((object == NULL) || (name == NULL))
    {
        return NULL;
    }

    current_element = object->child;
    if (case_sensitive)
    {
        while ((current_element != NULL) && (current_element->string != NULL) && (strcmp(name, current_element->string) != 0))
        {
            current_element = current_element->next;
        }
    }
    else
    {
        while ((current_element != NULL) && (case_insensitive_strcmp((const unsigned char*)name, (const unsigned char*)(current_element->string)) != 0))
        {
            current_element = current_element->next;
        }
    }

    if ((current_element == NULL) || (current_element->string == NULL)) {
        return NULL;
    }

    return current_element;
}

CJSON_PUBLIC(cJSON *) cJSON_GetObjectItem(const cJSON * const object, const char * const string)
{
    return get_object_item(object, string, false);
}

CJSON_PUBLIC(cJSON *) cJSON_GetObjectItemCaseSensitive(const cJSON * const object, const char * const string)
{
    return get_object_item(object, string, true);
}

CJSON_PUBLIC(cJSON_bool) cJSON_HasObjectItem(const cJSON *object, const char *string)
{
    return cJSON_GetObjectItem(object, string) ? 1 : 0;
}

/* Utility for array list handling. */
static void suffix_object(cJSON *prev, cJSON *item)
{
    prev->next = item;
    item->prev = prev;
}

/* Utility for handling references. */
static cJSON *create_reference(const cJSON *item, const internal_hooks * const hooks)
{
    cJSON *reference = NULL;
    if (item == NULL)
    {
        return NULL;
    }

    reference = cJSON_New_Item(hooks);
    if (reference == NULL)
    {
        return NULL;
    }

    memcpy(reference, item, sizeof(cJSON));
    reference->string = NULL;
    reference->type |= cJSON_IsReference;
    reference->next = reference->prev = NULL;
    return reference;
}

static cJSON_bool add_item_to_array(cJSON *array, cJSON *item)
{
    cJSON *child = NULL;

    if ((item == NULL) || (array == NULL) || (array == item))
    {
        return false;
    }

    child = array->child;
    /*
     * To find the last item in array quickly, we use prev in array
     */
    if (child == NULL)
    {
        /* list is empty, start new one */
        array->child = item;
        item->prev = item;
        item->next = NULL;
    }
    else
    {
        /* append to the end */
        if (child->prev)
        {
            suffix_object(child->prev, item);
            array->child->prev = item;
        }
        else
        {
            while (child->next)
            {
                child = child->next;
            }
            suffix_object(child, item);
            array->child->prev = item;
        }
    }

    return true;
}

/* Add item to array/object. */
CJSON_PUBLIC(cJSON_bool) cJSON_AddItemToArray(cJSON *array, cJSON *item)
{
    return add_item_to_array(array, item);
}

#if defined(__clang__) || (defined(__GNUC__)  && ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ > 5))))
    #pragma GCC diagnostic push
#endif
#ifdef __GNUC__
#pragma GCC diagnostic ignored "-Wcast-qual"
#endif
/* helper function to cast away const */
static void* cast_away_const(const void* string)
{
    return (void*)string;
}
#if defined(__clang__) || (defined(__GNUC__)  && ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ > 5))))
    #pragma GCC diagnostic pop
#endif


static cJSON_bool add_item_to_object(cJSON * const object, const char * const string, cJSON * const item, const internal_hooks * const hooks, const cJSON_bool constant_key)
{
    char *new_key = NULL;
    int new_type = cJSON_Invalid;

    if ((object == NULL) || (string == NULL) || (item == NULL) || (object == item))
    {
        return false;
    }

    if (constant_key)
    {
        new_key = (char*)cast_away_const(string);
        new_type = item->type | cJSON_StringIsConst;
    }
    else
    {
        new_key = (char*)cJSON_strdup((const unsigned char*)string, hooks);
        if (new_key == NULL)
        {
            return false;
        }

        new_type = item->type & ~cJSON_StringIsConst;
    }

    if (!(item->type & cJSON_StringIsConst) && (item->string != NULL))
    {
        hooks->deallocate(item->string);
    }

    item->string = new_key;
    item->type = new_type;

    return add_item_to_array(object, item);
}

CJSON_PUBLIC(cJSON_bool) cJSON_AddItemToObject(cJSON *object, const char *string, cJSON *item)
{
    return add_item_to_object(object, string, item, &global_hooks, false);
}

/* Add an item to an object with constant string as key */
CJSON_PUBLIC(cJSON_bool) cJSON_AddItemToObjectCS(cJSON *object, const char *string, cJSON *item)
{
    return add_item_to_object(object, string, item, &global_hooks, true);
}

CJSON_PUBLIC(cJSON_bool) cJSON_AddItemReferenceToArray(cJSON *array, cJSON *item)
{
    if (array == NULL)
    {
        return false;
    }

    return add_item_to_array(array, create_reference(item, &global_hooks));
}

CJSON_PUBLIC(cJSON_bool) cJSON_AddItemReferenceToObject(cJSON *object, const char *string, cJSON *item)
{
    if ((object == NULL) || (string == NULL))
    {
        return false;
    }

    return add_item_to_object(object, string, create_reference(item, &global_hooks), &global_hooks, false);
}

CJSON_PUBLIC(cJSON*) cJSON_AddNullToObject(cJSON * const object, const char * const name)
{
    cJSON *null = cJSON_CreateNull();
    if (add_item_to_object(object, name, null, &global_hooks, false))
    {
        return null;
    }

    cJSON_Delete(null);
    return NULL;
}

CJSON_PUBLIC(cJSON*) cJSON_AddTrueToObject(cJSON * const object, const char * const name)
{
    cJSON *true_item = cJSON_CreateTrue();
    if (add_item_to_object(object, name, true_item, &global_hooks, false))
    {
        return true_item;
    }

    cJSON_Delete(true_item);
    return NULL;
}

CJSON_PUBLIC(cJSON*) cJSON_AddFalseToObject(cJSON * const object, const char * const name)
{
    cJSON *false_item = cJSON_CreateFalse();
    if (add_item_to_object(object, name, false_item, &global_hooks, false))
    {
        return false_item;
    }

    cJSON_Delete(false_item);
    return NULL;
}

CJSON_PUBLIC(cJSON*) cJSON_AddBoolToObject(cJSON * const object, const char * const name, const cJSON_bool boolean)
{
    cJSON *bool_item = cJSON_CreateBool(boolean);
    if (add_item_to_object(object, name, bool_item, &global_hooks, false))
    {
        return bool_item;
    }

    cJSON_Delete(bool_item);
    return NULL;
}

CJSON_PUBLIC(cJSON*) cJSON_AddNumberToObject(cJSON * const object, const char * const name, const double number)
{
    cJSON *number_item = cJSON_CreateNumber(number);
    if (add_item_to_object(object, name, number_item, &global_hooks, false))
    {
        return number_item;
    }

    cJSON_Delete(number_item);
    return NULL;
}

CJSON_PUBLIC(cJSON*) cJSON_AddStringToObject(cJSON * const object, const char * const name, const char * const string)
{
    cJSON *string_item = cJSON_CreateString(string);
    if (add_item_to_object(object, name, string_item, &global_hooks, false))
    {
        return string_item;
    }

    cJSON_Delete(string_item);
    return NULL;
}

CJSON_PUBLIC(cJSON*) cJSON_AddRawToObject(cJSON * const object, const char * const name, const char * const raw)
{
    cJSON *raw_item = cJSON_CreateRaw(raw);
    if (add_item_to_object(object, name, raw_item, &global_hooks, false))
    {
        return raw_item;
    }

    cJSON_Delete(raw_item);
    return NULL;
}

CJSON_PUBLIC(cJSON*) cJSON_AddObjectToObject(cJSON * const object, const char * const name)
{
    cJSON *object_item = cJSON_CreateObject();
    if (add_item_to_object(object, name, object_item, &global_hooks, false))
    {
        return object_item;
    }

    cJSON_Delete(object_item);
    return NULL;
}

CJSON_PUBLIC(cJSON*) cJSON_AddArrayToObject(cJSON * const object, const char * const name)
{
    cJSON *array = cJSON_CreateArray();
    if (add_item_to_object(object, name, array, &global_hooks, false))
    {
        return array;
    }

    cJSON_Delete(array);
    return NULL;
}

CJSON_PUBLIC(cJSON *) cJSON_DetachItemViaPointer(cJSON *parent, cJSON * const item)
{
    if ((parent == NULL) || (item == NULL))
    {
        return NULL;
    }

    if (item != parent->child)
    {
        /* not the first element */
        item->prev->next = item->next;
    }
    if (item->next != NULL)
    {
        /* not the last element */
        item->next->prev = item->prev;
    }

    if (item == parent->child)
    {
        /* first element */
        parent->child = item->next;
    }
    /* make sure the detached item doesn't point anywhere anymore */
    item->prev = NULL;
    item->next = NULL;

    return item;
}

CJSON_PUBLIC(cJSON *) cJSON_DetachItemFromArray(cJSON *array, int which)
{
    if (which < 0)
    {
        return NULL;
    }

    return cJSON_DetachItemViaPointer(array, get_array_item(array, (size_t)which));
}

CJSON_PUBLIC(void) cJSON_DeleteItemFromArray(cJSON *array, int which)
{
    cJSON_Delete(cJSON_DetachItemFromArray(array, which));
}

CJSON_PUBLIC(cJSON *) cJSON_DetachItemFromObject(cJSON *object, const char *string)
{
    cJSON *to_detach = cJSON_GetObjectItem(object, string);

    return cJSON_DetachItemViaPointer(object, to_detach);
}

CJSON_PUBLIC(cJSON *) cJSON_DetachItemFromObjectCaseSensitive(cJSON *object, const char *string)
{
    cJSON *to_detach = cJSON_GetObjectItemCaseSensitive(object, string);

    return cJSON_DetachItemViaPointer(object, to_detach);
}

CJSON_PUBLIC(void) cJSON_DeleteItemFromObject(cJSON *object, const char *string)
{
    cJSON_Delete(cJSON_DetachItemFromObject(object, string));
}

CJSON_PUBLIC(void) cJSON_DeleteItemFromObjectCaseSensitive(cJSON *object, const char *string)
{
    cJSON_Delete(cJSON_DetachItemFromObjectCaseSensitive(object, string));
}

/* Replace array/object items with new ones. */
CJSON_PUBLIC(cJSON_bool) cJSON_InsertItemInArray(cJSON *array, int which, cJSON *newitem)
{
    cJSON *after_inserted = NULL;

    if (which < 0)
    {
        return false;
    }

    after_inserted = get_array_item(array, (size_t)which);
    if (after_inserted == NULL)
    {
        return add_item_to_array(array, newitem);
    }

    newitem->next = after_inserted;
    newitem->prev = after_inserted->prev;
    after_inserted->prev = newitem;
    if (after_inserted == array->child)
    {
        array->child = newitem;
    }
    else
    {
        newitem->prev->next = newitem;
    }
    return true;
}

CJSON_PUBLIC(cJSON_bool) cJSON_ReplaceItemViaPointer(cJSON * const parent, cJSON * const item, cJSON * replacement)
{
    if ((parent == NULL) || (replacement == NULL) || (item == NULL))
    {
        return false;
    }

    if (replacement == item)
    {
        return true;
    }

    replacement->next = item->next;
    replacement->prev = item->prev;

    if (replacement->next != NULL)
    {
        replacement->next->prev = replacement;
    }
    if (parent->child == item)
    {
        parent->child = replacement;
    }
    else
    {   /*
         * To find the last item in array quickly, we use prev in array.
         * We can't modify the last item's next pointer where this item was the parent's child
         */
        if (replacement->prev != NULL)
        {
            replacement->prev->next = replacement;
        }
    }

    item->next = NULL;
    item->prev = NULL;
    cJSON_Delete(item);

    return true;
}

CJSON_PUBLIC(cJSON_bool) cJSON_ReplaceItemInArray(cJSON *array, int which, cJSON *newitem)
{
    if (which < 0)
    {
        return false;
    }

    return cJSON_ReplaceItemViaPointer(array, get_array_item(array, (size_t)which), newitem);
}

static cJSON_bool replace_item_in_object(cJSON *object, const char *string, cJSON *replacement, cJSON_bool case_sensitive)
{
    if ((replacement == NULL) || (string == NULL))
    {
        return false;
    }

    /* replace the name in the replacement */
    if (!(replacement->type & cJSON_StringIsConst) && (replacement->string != NULL))
    {
        cJSON_free(replacement->string);
    }
    replacement->string = (char*)cJSON_strdup((const unsigned char*)string, &global_hooks);
    replacement->type &= ~cJSON_StringIsConst;

    return cJSON_ReplaceItemViaPointer(object, get_object_item(object, string, case_sensitive), replacement);
}

CJSON_PUBLIC(cJSON_bool) cJSON_ReplaceItemInObject(cJSON *object, const char *string, cJSON *newitem)
{
    return replace_item_in_object(object, string, newitem, false);
}

CJSON_PUBLIC(cJSON_bool) cJSON_ReplaceItemInObjectCaseSensitive(cJSON *object, const char *string, cJSON *newitem)
{
    return replace_item_in_object(object, string, newitem, true);
}

/* Create basic types: */
CJSON_PUBLIC(cJSON *) cJSON_CreateNull(void)
{
    cJSON *item = cJSON_New_Item(&global_hooks);
    if(item)
    {
        item->type = cJSON_NULL;
    }

    return item;
}

CJSON_PUBLIC(cJSON *) cJSON_CreateTrue(void)
{
    cJSON *item = cJSON_New_Item(&global_hooks);
    if(item)
    {
        item->type = cJSON_True;
    }

    return item;
}

CJSON_PUBLIC(cJSON *) cJSON_CreateFalse(void)
{
    cJSON *item = cJSON_New_Item(&global_hooks);
    if(item)
    {
        item->type = cJSON_False;
    }

    return item;
}

CJSON_PUBLIC(cJSON *) cJSON_CreateBool(cJSON_bool boolean)
{
    cJSON *item = cJSON_New_Item(&global_hooks);
    if(item)
    {
        item->type = boolean ? cJSON_True : cJSON_False;
    }

    return item;
}

CJSON_PUBLIC(cJSON *) cJSON_CreateNumber(double num)
{
    cJSON *item = cJSON_New_Item(&global_hooks);
    if(item)
    {
        item->type = cJSON_Number;
        item->valuedouble = num;

        /* use saturation in case of overflow */
        if (num >= INT_MAX)
        {
            item->valueint = INT_MAX;
        }
        else if (num <= (double)INT_MIN)
        {
            item->valueint = INT_MIN;
        }
        else
        {
            item->valueint = (int)num;
        }
    }

    return item;
}

CJSON_PUBLIC(cJSON *) cJSON_CreateString(const char *string)
{
    cJSON *item = cJSON_New_Item(&global_hooks);
    if(item)
    {
        item->type = cJSON_String;
        item->valuestring = (char*)cJSON_strdup((const unsigned char*)string, &global_hooks);
        if(!item->valuestring)
        {
            cJSON_Delete(item);
            return NULL;
        }
    }

    return item;
}

CJSON_PUBLIC(cJSON *) cJSON_CreateStringReference(const char *string)
{
    cJSON *item = cJSON_New_Item(&global_hooks);
    if (item != NULL)
    {
        item->type = cJSON_String | cJSON_IsReference;
        item->valuestring = (char*)cast_away_const(string);
    }

    return item;
}

CJSON_PUBLIC(cJSON *) cJSON_CreateObjectReference(const cJSON *child)
{
    cJSON *item = cJSON_New_Item(&global_hooks);
    if (item != NULL) {
        item->type = cJSON_Object | cJSON_IsReference;
        item->child = (cJSON*)cast_away_const(child);
    }

    return item;
}

CJSON_PUBLIC(cJSON *) cJSON_CreateArrayReference(const cJSON *child) {
    cJSON *item = cJSON_New_Item(&global_hooks);
    if (item != NULL) {
        item->type = cJSON_Array | cJSON_IsReference;
        item->child = (cJSON*)cast_away_const(child);
    }

    return item;
}

CJSON_PUBLIC(cJSON *) cJSON_CreateRaw(const char *raw)
{
    cJSON *item = cJSON_New_Item(&global_hooks);
    if(item)
    {
        item->type = cJSON_Raw;
        item->valuestring = (char*)cJSON_strdup((const unsigned char*)raw, &global_hooks);
        if(!item->valuestring)
        {
            cJSON_Delete(item);
            return NULL;
        }
    }

    return item;
}

CJSON_PUBLIC(cJSON *) cJSON_CreateArray(void)
{
    cJSON *item = cJSON_New_Item(&global_hooks);
    if(item)
    {
        item->type=cJSON_Array;
    }

    return item;
}

CJSON_PUBLIC(cJSON *) cJSON_CreateObject(void)
{
    cJSON *item = cJSON_New_Item(&global_hooks);
    if (item)
    {
        item->type = cJSON_Object;
    }

    return item;
}

/* Create Arrays: */
CJSON_PUBLIC(cJSON *) cJSON_CreateIntArray(const int *numbers, int count)
{
    size_t i = 0;
    cJSON *n = NULL;
    cJSON *p = NULL;
    cJSON *a = NULL;

    if ((count < 0) || (numbers == NULL))
    {
        return NULL;
    }

    a = cJSON_CreateArray();
    for(i = 0; a && (i < (size_t)count); i++)
    {
        n = cJSON_CreateNumber(numbers[i]);
        if (!n)
        {
            cJSON_Delete(a);
            return NULL;
        }
        if(!i)
        {
            a->child = n;
        }
        else
        {
            suffix_object(p, n);
        }
        p = n;
    }

    return a;
}

CJSON_PUBLIC(cJSON *) cJSON_CreateFloatArray(const float *numbers, int count)
{
    size_t i = 0;
    cJSON *n = NULL;
    cJSON *p = NULL;
    cJSON *a = NULL;

    if ((count < 0) || (numbers == NULL))
    {
        return NULL;
    }

    a = cJSON_CreateArray();

    for(i = 0; a && (i < (size_t)count); i++)
    {
        n = cJSON_CreateNumber((double)numbers[i]);
        if(!n)
        {
            cJSON_Delete(a);
            return NULL;
        }
        if(!i)
        {
            a->child = n;
        }
        else
        {
            suffix_object(p, n);
        }
        p = n;
    }

    return a;
}

CJSON_PUBLIC(cJSON *) cJSON_CreateDoubleArray(const double *numbers, int count)
{
    size_t i = 0;
    cJSON *n = NULL;
    cJSON *p = NULL;
    cJSON *a = NULL;

    if ((count < 0) || (numbers == NULL))
    {
        return NULL;
    }

    a = cJSON_CreateArray();

    for(i = 0;a && (i < (size_t)count); i++)
    {
        n = cJSON_CreateNumber(numbers[i]);
        if(!n)
        {
            cJSON_Delete(a);
            return NULL;
        }
        if(!i)
        {
            a->child = n;
        }
        else
        {
            suffix_object(p, n);
        }
        p = n;
    }

    return a;
}

CJSON_PUBLIC(cJSON *) cJSON_CreateStringArray(const char *const *strings, int count)
{
    size_t i = 0;
    cJSON *n = NULL;
    cJSON *p = NULL;
    cJSON *a = NULL;

    if ((count < 0) || (strings == NULL))
    {
        return NULL;
    }

    a = cJSON_CreateArray();

    for (i = 0; a && (i < (size_t)count); i++)
    {
        n = cJSON_CreateString(strings[i]);
        if(!n)
        {
            cJSON_Delete(a);
            return NULL;
        }
        if(!i)
        {
            a->child = n;
        }
        else
        {
            suffix_object(p,n);
        }
        p = n;
    }

    return a;
}

/* Duplication */
CJSON_PUBLIC(cJSON *) cJSON_Duplicate(const cJSON *item, cJSON_bool recurse)
{
    cJSON *newitem = NULL;
    cJSON *child = NULL;
    cJSON *next = NULL;
    cJSON *newchild = NULL;

    /* Bail on bad ptr */
    if (!item)
    {
        goto fail;
    }
    /* Create new item */
    newitem = cJSON_New_Item(&global_hooks);
    if (!newitem)
    {
        goto fail;
    }
    /* Copy over all vars */
    newitem->type = item->type & (~cJSON_IsReference);
    newitem->valueint = item->valueint;
    newitem->valuedouble = item->valuedouble;
    if (item->valuestring)
    {
        newitem->valuestring = (char*)cJSON_strdup((unsigned char*)item->valuestring, &global_hooks);
        if (!newitem->valuestring)
        {
            goto fail;
        }
    }
    if (item->string)
    {
        newitem->string = (item->type&cJSON_StringIsConst) ? item->string : (char*)cJSON_strdup((unsigned char*)item->string, &global_hooks);
        if (!newitem->string)
        {
            goto fail;
        }
    }
    /* If non-recursive, then we're done! */
    if (!recurse)
    {
        return newitem;
    }
    /* Walk the ->next chain for the child. */
    child = item->child;
    while (child != NULL)
    {
        newchild = cJSON_Duplicate(child, true); /* Duplicate (with recurse) each item in the ->next chain */
        if (!newchild)
        {
            goto fail;
        }
        if (next != NULL)
        {
            /* If newitem->child already set, then crosswire ->prev and ->next and move on */
            next->next = newchild;
            newchild->prev = next;
            next = newchild;
        }
        else
        {
            /* Set newitem->child and move to it */
            newitem->child = newchild;
            next = newchild;
        }
        child = child->next;
    }

    return newitem;

fail:
    if (newitem != NULL)
    {
        cJSON_Delete(newitem);
    }

    return NULL;
}

static void skip_oneline_comment(char **input)
{
    *input += static_strlen("//");

    for (; (*input)[0] != '\0'; ++(*input))
    {
        if ((*input)[0] == '\n') {
            *input += static_strlen("\n");
            return;
        }
    }
}

static void skip_multiline_comment(char **input)
{
    *input += static_strlen("/*");

    for (; (*input)[0] != '\0'; ++(*input))
    {
        if (((*input)[0] == '*') && ((*input)[1] == '/'))
        {
            *input += static_strlen("*/");
            return;
        }
    }
}

static void minify_string(char **input, char **output) {
    (*output)[0] = (*input)[0];
    *input += static_strlen("\"");
    *output += static_strlen("\"");


    for (; (*input)[0] != '\0'; (void)++(*input), ++(*output)) {
        (*output)[0] = (*input)[0];

        if ((*input)[0] == '\"') {
            (*output)[0] = '\"';
            *input += static_strlen("\"");
            *output += static_strlen("\"");
            return;
        } else if (((*input)[0] == '\\') && ((*input)[1] == '\"')) {
            (*output)[1] = (*input)[1];
            *input += static_strlen("\"");
            *output += static_strlen("\"");
        }
    }
}

CJSON_PUBLIC(void) cJSON_Minify(char *json)
{
    char *into = json;

    if (json == NULL)
    {
        return;
    }

    while (json[0] != '\0')
    {
        switch (json[0])
        {
            case ' ':
            case '\t':
            case '\r':
            case '\n':
                json++;
                break;

            case '/':
                if (json[1] == '/')
                {
                    skip_oneline_comment(&json);
                }
                else if (json[1] == '*')
                {
                    skip_multiline_comment(&json);
                } else {
                    json++;
                }
                break;

            case '\"':
                minify_string(&json, (char**)&into);
                break;

            default:
                into[0] = json[0];
                json++;
                into++;
        }
    }

    /* and null-terminate. */
    *into = '\0';
}

CJSON_PUBLIC(cJSON_bool) cJSON_IsInvalid(const cJSON * const item)
{
    if (item == NULL)
    {
        return false;
    }

    return (item->type & 0xFF) == cJSON_Invalid;
}

CJSON_PUBLIC(cJSON_bool) cJSON_IsFalse(const cJSON * const item)
{
    if (item == NULL)
    {
        return false;
    }

    return (item->type & 0xFF) == cJSON_False;
}

CJSON_PUBLIC(cJSON_bool) cJSON_IsTrue(const cJSON * const item)
{
    if (item == NULL)
    {
        return false;
    }

    return (item->type & 0xff) == cJSON_True;
}


CJSON_PUBLIC(cJSON_bool) cJSON_IsBool(const cJSON * const item)
{
    if (item == NULL)
    {
        return false;
    }

    return (item->type & (cJSON_True | cJSON_False)) != 0;
}
CJSON_PUBLIC(cJSON_bool) cJSON_IsNull(const cJSON * const item)
{
    if (item == NULL)
    {
        return false;
    }

    return (item->type & 0xFF) == cJSON_NULL;
}

CJSON_PUBLIC(cJSON_bool) cJSON_IsNumber(const cJSON * const item)
{
    if (item == NULL)
    {
        return false;
    }

    return (item->type & 0xFF) == cJSON_Number;
}

CJSON_PUBLIC(cJSON_bool) cJSON_IsString(const cJSON * const item)
{
    if (item == NULL)
    {
        return false;
    }

    return (item->type & 0xFF) == cJSON_String;
}

CJSON_PUBLIC(cJSON_bool) cJSON_IsArray(const cJSON * const item)
{
    if (item == NULL)
    {
        return false;
    }

    return (item->type & 0xFF) == cJSON_Array;
}

CJSON_PUBLIC(cJSON_bool) cJSON_IsObject(const cJSON * const item)
{
    if (item == NULL)
    {
        return false;
    }

    return (item->type & 0xFF) == cJSON_Object;
}

CJSON_PUBLIC(cJSON_bool) cJSON_IsRaw(const cJSON * const item)
{
    if (item == NULL)
    {
        return false;
    }

    return (item->type & 0xFF) == cJSON_Raw;
}

CJSON_PUBLIC(cJSON_bool) cJSON_Compare(const cJSON * const a, const cJSON * const b, const cJSON_bool case_sensitive)
{
    if ((a == NULL) || (b == NULL) || ((a->type & 0xFF) != (b->type & 0xFF)) || cJSON_IsInvalid(a))
    {
        return false;
    }

    /* check if type is valid */
    switch (a->type & 0xFF)
    {
        case cJSON_False:
        case cJSON_True:
        case cJSON_NULL:
        case cJSON_Number:
        case cJSON_String:
        case cJSON_Raw:
        case cJSON_Array:
        case cJSON_Object:
            break;

        default:
            return false;
    }

    /* identical objects are equal */
    if (a == b)
    {
        return true;
    }

    switch (a->type & 0xFF)
    {
        /* in these cases and equal type is enough */
        case cJSON_False:
        case cJSON_True:
        case cJSON_NULL:
            return true;

        case cJSON_Number:
            if (compare_double(a->valuedouble, b->valuedouble))
            {
                return true;
            }
            return false;

        case cJSON_String:
        case cJSON_Raw:
            if ((a->valuestring == NULL) || (b->valuestring == NULL))
            {
                return false;
            }
            if (strcmp(a->valuestring, b->valuestring) == 0)
            {
                return true;
            }

            return false;

        case cJSON_Array:
        {
            cJSON *a_element = a->child;
            cJSON *b_element = b->child;

            for (; (a_element != NULL) && (b_element != NULL);)
            {
                if (!cJSON_Compare(a_element, b_element, case_sensitive))
                {
                    return false;
                }

                a_element = a_element->next;
                b_element = b_element->next;
            }

            /* one of the arrays is longer than the other */
            if (a_element != b_element) {
                return false;
            }

            return true;
        }

        case cJSON_Object:
        {
            cJSON *a_element = NULL;
            cJSON *b_element = NULL;
            cJSON_ArrayForEach(a_element, a)
            {
                /* TODO This has O(n^2) runtime, which is horrible! */
                b_element = get_object_item(b, a_element->string, case_sensitive);
                if (b_element == NULL)
                {
                    return false;
                }

                if (!cJSON_Compare(a_element, b_element, case_sensitive))
                {
                    return false;
                }
            }

            /* doing this twice, once on a and b to prevent true comparison if a subset of b
             * TODO: Do this the proper way, this is just a fix for now */
            cJSON_ArrayForEach(b_element, b)
            {
                a_element = get_object_item(a, b_element->string, case_sensitive);
                if (a_element == NULL)
                {
                    return false;
                }

                if (!cJSON_Compare(b_element, a_element, case_sensitive))
                {
                    return false;
                }
            }

            return true;
        }

        default:
            return false;
    }
}

CJSON_PUBLIC(void *) cJSON_malloc(size_t size)
{
    return global_hooks.allocate(size);
}

CJSON_PUBLIC(void) cJSON_free(void *object)
{
    global_hooks.deallocate(object);
}

 

---

 參考：

https://blog.csdn.net/shizhe0123/article/details/94742514

https://blog.csdn.net/fengxinlinux/article/details/53121287

https://www.cnblogs.com/skullboyer/p/8152157.html