diff --git a/include/common.h b/include/common.h
index b70aa51..5518d3d 100644
--- a/include/common.h
+++ b/include/common.h
@@ -44,8 +44,11 @@ void string_list_debug(char *describe, char **string_list);
 void uint32_list_debug(char *describe, uint32_t **uint32_list);
 
 uint8_t check_port(uint16_t port);
+uint16_t gen_rand_num(uint16_t limit);
 char* uint32_to_string(uint32_t number);
 
+int run_command(const char *command);
+
 char* string_init(const char *str);
 char* string_join(const char *base, const char *add);
 
diff --git a/include/utils/toJSON.h b/include/utils/toJSON.h
new file mode 100644
index 0000000..3ea5552
--- /dev/null
+++ b/include/utils/toJSON.h
@@ -0,0 +1,6 @@
+#ifndef _TO_JSON_H_
+#define _TO_JSON_H_
+
+char* to_json(const char *config_file);
+
+#endif
diff --git a/src/cleardns.c b/src/cleardns.c
index 56294e1..0837dea 100644
--- a/src/cleardns.c
+++ b/src/cleardns.c
@@ -1,10 +1,13 @@
 #include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
 #include "loader.h"
 #include "logger.h"
 #include "common.h"
 #include "dnsproxy.h"
 #include "overture.h"
 #include "structure.h"
+#include "toJSON.h"
 
 //#include <stdio.h>
 //#include <string.h>
@@ -36,6 +39,11 @@ int main(int argc, char *argv[]) { // ClearDNS server
     LOG_LEVEL = LOG_DEBUG;
     log_info("ClearDNS server start (%s)", VERSION);
 
+    char *str = to_json("AdGuardHome.yaml");
+    log_info("%s", str);
+    return 0;
+
+
 //    load_config("test.json");
 //
 //    dnsproxy_load("Domestic", loader.domestic, "domestic.json");
diff --git a/src/common.c b/src/common.c
index 036e1c6..cce8d0d 100644
--- a/src/common.c
+++ b/src/common.c
@@ -1,6 +1,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <time.h>
+#include <sys/time.h>
 #include "common.h"
 #include "logger.h"
 #include "structure.h"
@@ -47,6 +49,17 @@ char* uint32_to_string(uint32_t number) {
     return string_init(to_str);
 }
 
+uint16_t gen_rand_num(uint16_t limit) { // 0 ~ (limit - 1)
+    struct timeval tv;
+    gettimeofday(&tv, NULL);
+    srand(tv.tv_usec);
+    return rand() % limit; // NOLINT
+}
+
+int run_command(const char *command) {
+    return system(command) / 256;
+}
+
 void save_file(const char *file, const char *content) { // save into file
     log_debug("Write into `%s` -> \n%s", file, content);
     FILE* fp = fopen(file , "w");
diff --git a/src/utils/CMakeLists.txt b/src/utils/CMakeLists.txt
index 3cff9f5..192d2e7 100644
--- a/src/utils/CMakeLists.txt
+++ b/src/utils/CMakeLists.txt
@@ -1,3 +1,3 @@
 cmake_minimum_required(VERSION 2.8.12)
 
-add_library(utils cJSON.c logger.c process.c structure.c)
+add_library(utils cJSON.c toJSON.c logger.c process.c structure.c)
diff --git a/src/utils/toJSON.c b/src/utils/toJSON.c
new file mode 100644
index 0000000..12bc90a
--- /dev/null
+++ b/src/utils/toJSON.c
@@ -0,0 +1,30 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "toJSON.h"
+#include "logger.h"
+#include "common.h"
+
+char* to_json(const char *file) {
+    char flag[9];
+    for (int i = 0; i < 8; ++i) { // generate 8-bits flag
+        flag[i] = (char)gen_rand_num(10);
+        flag[i] += 48;
+    }
+    flag[8] = '\0';
+    char *output_file = string_join("/tmp/tojson-", flag);
+    char *to_json_cmd = (char *)malloc(strlen(file) + strlen(output_file) + 11);
+    sprintf(to_json_cmd, "toJSON %s > %s", file, output_file);
+    log_debug("JSON format command -> `%s`", to_json_cmd);
+    if (run_command(to_json_cmd)) { // toJSON return non-zero code
+        return NULL; // convert failed
+    }
+    free(to_json_cmd);
+
+    char *json_content = read_file(output_file);
+    char *rm_cmd = string_join("rm -f ", output_file);
+    run_command(rm_cmd);
+    free(output_file);
+    free(rm_cmd);
+    return json_content;
+}