c - IOT Client-server communication using JSON object -

i have written code client server communication using iot... using json object parsing... api json_object_object_foreach(jobj,key,val) not getting executed, giving segmentation fault. please find out solution , let me know.

server.c

#include <unistd.h> #include <string.h> #include <json/json.h> #include<stdio.h> #include <sys/types.h>        #include <sys/socket.h> #include <stdlib.h> #include<netinet/ip.h> #include<arpa/inet.h> #include<errno.h> #include<sys/ioctl.h> #include<fcntl.h>  #define magic 'k' #define my_cmd1 _iowr(magic,1,int *)  struct stepper {         int rot;         int dir;         int angle; }step;  char buf[1024]; int x,y,z,i=0; int a[3]; void json_parse(json_object *jobj,int *a) {      enum json_type type;     printf("type: ",type);       printf("json parsed\n");     json_object_object_foreach(jobj,key,val)         {         type = json_object_get_type(val);         switch (type)          {     printf("json parsed 1\n");         case json_type_int: printf("json_type_intn\n");         printf("the value %d\n", a[i++]=json_object_get_int(val));     break;         }         } }  int main(int argc,char *argv[]) { int sockfd,accptfd,len; int fd,cmd,d,q; char buf[1024]; struct sockaddr_in server,client; server.sin_family=af_inet; server.sin_port=htons(atoi(argv[1])); server.sin_addr.s_addr = inaddr_any; sockfd=socket(af_inet,sock_stream,0); if(sockfd<0) printf("the fd %d\n",sockfd); printf("before bind\n"); bind(sockfd,(struct sockaddr *)&server,sizeof(server)); perror("bind"); listen(sockfd,5); len=sizeof(client); printf("the server up\n"); accptfd=accept(sockfd,(struct sockaddr *)&client,&len); send(accptfd,"hello server",14,0); recv(accptfd,buf,14,0); printf("rec data %s\n",buf); fd=open("stepp",o_rdwr);         printf("enter stepper motor specification\n");     q=recv(accptfd,buf,1024,0);     puts(buf);     json_object * jobj = json_tokener_parse(buf);     printf("the json obj %s\n",json_object_to_json_string(jobj));     json_parse(jobj,a);            ioctl(fd,my_cmd1,&step);         close(fd);     close(accptfd);     close(sockfd); return 0; } 

client.c

#include<stdio.h> #include<sys/socket.h> #include<sys/types.h> #include<netinet/ip.h> #include<netinet/in.h> #include<arpa/inet.h> #include<unistd.h> #include<json/json.h> #include<stdlib.h>  char *str="{\"a\":1,\"b\":2,\"c\":360}"; int main(int argc, char *argv[]) {     int sock_s,sock_c,s_len;     char buf[20];     char buf1[20]="hello server";     struct sockaddr_in server;     server.sin_family = af_inet;     server.sin_addr.s_addr = inet_addr(argv[1]);     server.sin_port = htons(atoi(argv[2]));     s_len = sizeof(server);      sock_s = socket(af_inet,sock_stream,0);     printf("the str %s\n",str);      if(connect(sock_s,(struct sockaddr *)&server,s_len)<0)     {     perror("connect:");     }     recv(sock_s,buf,20,0);     printf("the read dat %s\n",buf);      printf("enter data send\n");     scanf("%s",buf);     send(sock_s,buf,20,0);     send(sock_s,str,1024,0);     close(sock_s);     return 0; }