void _main(){char * data;_union_type my_union;char data_buf[100]="";data=data_buf;strcpy(data, BAD_OS_COMMAND);my_union.a=data;{char * data=my_union.b;system(data);}}
static void main(){char * data;_union_type my_union;char data_buf[100]="";data=data_buf;strcpy(data, GOOD_OS_COMMAND);my_union.a=data;{char * data=my_union.b;system(data);}}