YAJL을 통해 json 문 생성

/*
 *             yajl  json  。
 *           ，             。
 */

#include <yajl/yajl_gen.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

//#define USE_MAP 1
#define BEAUTIFY_OUTPUT 1

typedef struct yajl_info_t
{
    int depth;
    yajl_gen gen; //    generator
} yajl_info;


/*
 * begin_map end_map       
 *            ，        /  
 */
yajl_gen_status begin_map(void *ctx)
{
    yajl_info *info = (yajl_info *)ctx;
    yajl_gen_status __stat = yajl_gen_map_open(info->gen);
    if (__stat == yajl_gen_status_ok)  {
        info->depth++ ;
    } else {
        printf("yajl_gen_map_open failed
");
    }
    return __stat;
}

/*
 * begin_map end_map       
 *            ，         
 */
yajl_gen_status begin_array(void *ctx)
{
    yajl_info *info = (yajl_info *)ctx;
    yajl_gen_status __stat = yajl_gen_array_open(info->gen);
    if (__stat == yajl_gen_status_ok)  {
        info->depth++;
    } else {
        printf("yajl_gen_array_open failed
");
    }
    return __stat;
}

yajl_gen_status end_array(void *ctx)
{
    yajl_info *info = (yajl_info *)ctx;
    yajl_gen_status __stat = yajl_gen_array_close(info->gen);
    if (__stat == yajl_gen_status_ok) {
        info->depth--;
    }
    return __stat;
}

int yajl_init(yajl_info *info) {
    info->depth = 0;
    info->gen = yajl_gen_alloc(NULL);
#ifdef BEAUTIFY_OUTPUT
    //      
    yajl_gen_config(info->gen, yajl_gen_beautify, 1);
#endif
}

int yajl_free(yajl_info *info) {
    info->depth = 0;
    yajl_gen_free(info->gen);
}

int main(int argc, char **argv)
{
    yajl_info yajlinfo;
    yajl_init (&yajlinfo);
    const unsigned char* buf;
    size_t buflen;
    int i;

#ifdef USE_MAP
    //      
    begin_map(&yajlinfo);
#else
    //      
    begin_array(&yajlinfo);
#endif

    //   /       
    unsigned char *key = "scutech";
    unsigned char *value = "dingjia";
    int keylen = strlen(key);
    int valuelen = strlen(value);
    yajl_gen_string(yajlinfo.gen, (const unsigned char*)key, keylen);
    yajl_gen_string(yajlinfo.gen, (const unsigned char*)value, valuelen);

    for(i=1;i<5;i++) {
        unsigned char key1[50];
        unsigned char value1[50];
        sprintf(key1, "scutech%d", i);
        sprintf(value1, "dingjia%d", i);
        int keylen1 = strlen(key1);
        int valuelen1 = strlen(value1);
        //        
        begin_map(&yajlinfo);
        yajl_gen_string(yajlinfo.gen, (const unsigned char*)key1, keylen1);
        yajl_gen_string(yajlinfo.gen, (const unsigned char*)value1, valuelen1);
        end_map(&yajlinfo);
    }

#ifdef USE_MAP
    end_map(&yajlinfo);
#else
    end_array(&yajlinfo);
#endif
    //           json  ，   buf ，     buflen 
    yajl_gen_get_buf(yajlinfo.gen, &buf, &buflen);
    printf("%s
", buf);
    yajl_free(&yajlinfo);
    return 0;