// get_ib_users.cpp
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ibase.h>

struct userinfo {
 char username[ 50 ];
 char firstname[ 50 ];
 char middlename[ 50 ];
 char lastname[ 50 ];
 ISC_ULONG userid;
 ISC_ULONG groupid;
};

struct users_list {
 int count;
 int size;
 userinfo *list;
} list;

ISC_STATUS status[ 20 ];
isc_svc_handle service_handle=NULL;

char request_buffer[] = {
  isc_info_svc_get_users
};

char request[ 300 ];
static char buffer[ 1024 ];

void insert_user(userinfo *info) {
 if (!info) return;
 if (list.count>=list.size) {
  list.size+= 10 ;
  list.list=(userinfo *) realloc(list.list,list.size*sizeof(userinfo));
 }
 list.list[list.count++]=*info;
}

void store_svc_char_info(char *&from, char *to, int size) {
 ISC_USHORT len=isc_vax_integer(from,sizeof(ISC_SHORT));
 from+=sizeof(ISC_SHORT);
 if (len>size) len=size;
 while(len--) *to++=*from++;
 *to= 0 ;
}

int svc_attach(char *user, char *password, char *service_name) {
 char spb_buffer[ 128 ];
 char *spb = spb_buffer;
 unsigned short spb_length;

 if (!user || !password || !service_name) return - 1 ;

 *spb++ = isc_spb_version;
 *spb++ = isc_spb_current_version;
 *spb++ = isc_spb_user_name;
 *spb++ = strlen(user);
 strcpy(spb, user);
 spb += strlen(user);
 *spb++ = isc_spb_password;
 *spb++ = strlen(password);
 strcpy(spb, password);
 spb += strlen(password);
 spb_length = spb - spb_buffer;
 
 if (isc_service_attach(status,  0 , service_name, &service_handle, spb_length, spb_buffer))  {
  isc_print_status(status);
  return - 1 ;
 }
 
 return  0 ;
}

int svc_detach() {
 if (isc_service_detach(status, &service_handle)) {
  isc_print_status(status);
  return - 1 ;
 }
 return  0 ;
}


int svc_get_users() {
 struct userinfo info;
 char *p = request;

 unsigned long options;

 *p++ = isc_action_svc_display_user;

 if (isc_service_start(status, &service_handle, NULL, p - request,request)) {
  isc_print_status(status);
  return - 1 ;
 }
 
 if (isc_service_query(status, 
    &service_handle, NULL,  0 ,NULL,
     sizeof(request_buffer), request_buffer,
    sizeof(buffer), buffer   
 )) {
    isc_print_status(status);
    return - 1 ;
 }

 p=buffer+ 1 +sizeof(ISC_SHORT);
 while (*p!=isc_info_end) {
   
   switch (*p++) {
    case isc_spb_sec_username:
	 store_svc_char_info(p,info.username,sizeof(info.username));    
	 break;
    case isc_spb_sec_firstname:
	 store_svc_char_info(p,info.firstname,sizeof(info.firstname));    
	 break;
    case isc_spb_sec_middlename:
	 store_svc_char_info(p,info.middlename,sizeof(info.middlename));    
	 break;
    case isc_spb_sec_lastname:
	 store_svc_char_info(p,info.lastname,sizeof(info.lastname));        
	 break;
    case isc_spb_sec_groupid:
	 info.groupid=isc_vax_integer(p,sizeof(ISC_ULONG));
	 p+=sizeof(ISC_ULONG);
	 insert_user(&info);
	 break;
    case isc_spb_sec_userid:
	 info.userid=isc_vax_integer(p,sizeof(ISC_ULONG));
	 p+=sizeof(ISC_ULONG);
	 break;
   }
 }
 
 return  0 ;
}

void display_users() {
 int i;
 printf("Got %u users\n",list.count);
 for(i= 0 ; i<list.count; i++) {
   printf("Username: %s\n",list.list[i].username);
   printf("Firstname: %s\n",list.list[i].firstname);
   printf("Middlename: %s\n",list.list[i].middlename);
   printf("Lastname: %s\n",list.list[i].lastname);
   printf("User id: %u\n",list.list[i].userid);
   printf("Group id: %u\n",list.list[i].groupid);
   puts("------------------------");
 }
}

int main() {
 if (svc_attach("sysdba","masterkey","localhost:service_mgr")) return - 1 ;
 list.count= 0 ; list.size= 10 ; list.list=(userinfo *) malloc(sizeof(userinfo)*list.size);
 if (svc_get_users()) return - 1 ;
 if (svc_detach()) return - 1 ;
 display_users();
 free(list.list);
 return  0 ;
}