1. 概述：
该demo主要实现linux下JSON配置文件的基本操作，解析
引用cJSON库的地址为：https://github.com/DaveGamble/cJSON

2. 测试：

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

#include "cJSON.h"

void doit(char * text)
{ 
    int i = 0, j = 0;
    char * out = NULL;
    cJSON * json = NULL;

    json = cJSON_Parse(text);
    if (!json) { 
        printf("Error before: [%s]\n", cJSON_GetErrorPtr());
    }
    else{ 
        out = cJSON_Print(json);
        printf("%s\n\n", out);
        free(out);
        out = NULL;

        cJSON * json_province = cJSON_GetArrayItem(json, 0);
        out = cJSON_Print(json_province);
        printf("%s\n", out);
        free(out);
        printf("name = %s\n\n", cJSON_GetObjectItem(json, "name")->valuestring);

        cJSON * json_area = cJSON_GetArrayItem(json, 1);
        out = cJSON_Print(json_area);
        printf("%s\n", out);
        free(out);

        for(i = 0; i < cJSON_GetArraySize(json_area); i ++){ 

            cJSON * json_city = cJSON_GetArrayItem(json_area, i);
            if(NULL == json_city){ 
                continue;
            }
            out = cJSON_Print(json_city);
            printf("%s\n", out);
            free(out);

            for(j = 0; j < cJSON_GetArraySize(json_city); j ++ ){ 
                cJSON * Citylist = cJSON_GetArrayItem(json_city, j);
                if(NULL == Citylist){ 
                    continue;
                }
                printf("Citylist[%d] : %s\n", j, Citylist->valuestring);
            }
        }

        cJSON_Delete(json);
    }
}

void dofile(char * filename)
{ 
    FILE * file = NULL;
    long len = 0;
    char * data = NULL;

    file = fopen(filename, "rb");

    fseek(file, 0, SEEK_END);

    len = ftell(file);

    fseek(file, 0, SEEK_SET);

    data=(char*)malloc(len + 1);

    fread(data, 1, len, file);

    fclose(file);

    doit(data);

    free(data);

    return ;
}

int main(int argc, char **argv){ 

    dofile("./cjson");

    return 0;
}

#Makefile
CC := gcc
AR := ar

all:
	$(CC) -c cJSON.c -o cJSON.o -Wall -Werror
	$(AR) cr libcJSON.a cJSON.o
	#-L 指定库的路径 -l 指定需连接的库名
	#-Wl,-Bstatic指示跟在后面的-lxxx选项链接的都是静态库 
	#-Wl,-Bdynamic指示跟在后面的-lxxx选项链接的都是动态库
	$(CC) demo_cjson.c -o demo_cjson -lm -L. -Wl,-Bstatic -lcJSON -Wl,-Bdynamic -Wall -Werror

clean:
	rm demo_cjson *.o *.a

{ 
    "name": "黑龙江",
    "cities": { 
        "city": ["哈尔滨", "大庆"]
    }
}