DatabaseClientExample

    // ------------------------------- //
    // -------- Start of File -------- //
    // ------------------------------- //
    // ----------------------------------------------------------- //
    // C++ Source Code File Name: client.cpp
    // C++ Compiler Used: MSVC, BCC32, GCC, HPUX aCC, SOLARIS CC
    // Produced By: DataReel Software Development Team
    // File Creation Date: 09/20/1999
    // Date Last Modified: 06/17/2016
    // Copyright (c) 2001-2016 DataReel Software Development
    // ----------------------------------------------------------- //
    // ------------- Program Description and Details ------------- //
    // ----------------------------------------------------------- //
    /*
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
    USA

    This program is used to demonstrate how to stream database blocks
    across a network connection.
    */
    // ----------------------------------------------------------- //
    #include "gxdlcode.h"

    #if defined (__USE_ANSI_CPP__) // Use the ANSI Standard C++ library
    #include <iostream>
    using namespace std; // Use unqualified names for Standard C++ library
    #else // Use the old iostream library by default
    #include <iostream.h>
    #endif // __USE_ANSI_CPP__

    #include <stdlib.h>
    #include <string.h>
    #include "gxstream.h"
    #include "dbobject.h"

    void ClearInputStream(istream &s)
    // Used to clear istream
    {
      char c;
      s.clear();
      while(s.get(c) && c != '\n') { ; }
    }

    void InputName(const char *mesg, DatabaseObjectData &dbobject)
    {
      cout << mesg;
      char buf[gxMaxNameLength];
      for(int i = 0; i < gxMaxNameLength; i++) buf[i] = 0;
      cin >> buf;
      strcpy(dbobject.name, buf);
    }

    void DisplayDatabaseObject(DatabaseObjectData &dbobject, int full = 1)
    {
      cout << "\n";
      cout << "Database object name: " << dbobject.name << "\n";
      if(full) {
        cout << "Database object OID:  " << dbobject.oid << "\n";
        cout.setf(ios::showpoint | ios::fixed);
        cout.precision(3);
        cout << "Database object CID:  " << dbobject.cid << "\n";
        cout << "\n";
      }
    }

    void PrgMenu()
    {
      cout << "\n";
      cout << "(a, A)    Add an object to the database" << "\n";
      cout << "(c, C)    Change an object in the database" << "\n";
      cout << "(d, D)    Delete an object in the database" << "\n";
      cout << "(f, F)    Find an object in the database" << "\n";
      cout << "(h, H, ?) Help (prints this menu)" << "\n";
      cout << "(k, K)    Shutdown the server" << "\n";
      cout << "(q, Q)    Quit this program" << "\n";
      cout << "\n";
    }

    void DeleteObject(int port, char *host)
    {
      gxStream client;
      if(client.StreamClient(port, host) != 0) {
        cout << client.SocketExceptionMessage() << "\n";
        client.Close();
        return;
      }

      cout << "Deleting an object from the database" << "\n";
      DatabaseObjectData dbobject;
      ClearInputStream(cin);
      InputName("Enter the name of the object to delete: ", dbobject);

      gxBlockHeader blk;
      blk.block_length = sizeof(DatabaseObjectData);

      if(client.DeleteBlock((char *)&dbobject, blk) != 0)
        cout << client.SocketExceptionMessage() << "\n";

      client.Close();
    }

    void AddObject(int port, char *host)
    {
      gxStream client;
      if(client.StreamClient(port, host) != 0) {
        cout << client.SocketExceptionMessage() << "\n";
        client.Close();
        return;
      }

      DatabaseObjectData dbobject;
      ClearInputStream(cin);
      InputName("Enter the name of the new object: ", dbobject);
      int id;
      double cid;

      cout << "Enter the object's id number: ";
      cin >> id;
      if(cin) {
        dbobject.oid = id;
        cout << "Enter the object's class id number: ";
        cin >> cid;
      }
      else {
        cout << "Invalid entry. Object not added!" << "\n";
        return;
      }
      if(cin) {
        dbobject.cid = cid;
      }
      else {
        cout << "Invalid entry. Object not added!" << "\n";
        return;
      }

      ClearInputStream(cin);

      cout << "Sending a request to add the object" << "\n";

      gxBlockHeader blk;
      blk.block_length = sizeof(DatabaseObjectData);

      if(client.AddBlock((char *)&dbobject, blk) != 0)
        cout << client.SocketExceptionMessage() << "\n";

      client.Close();
    }

    void ChangeObject(int port, char *host)
    {
      gxStream client;
      if(client.StreamClient(port, host) != 0) {
        cout << client.SocketExceptionMessage() << "\n";
        client.Close();
        return;
      }

      cout << "Changing and object in the database" << "\n";
      DatabaseObjectData dbobject;
      ClearInputStream(cin);
      InputName("Enter the name of the object to change: ", dbobject);

      DatabaseObjectData new_dbobject_info;
      InputName("Enter the object's new name: ", new_dbobject_info);
      int id;
      double cid;

      cout << "Enter the object's new ID number: ";
      cin >> id;
      if(cin) {
        new_dbobject_info.oid = id;
        cout << "Enter the object's new class ID: ";
        cin >> cid;
      }
      else {
        cout << "Invalid entry. Object not added!" << "\n";
        return;
      }
      if(cin) {
        new_dbobject_info.cid = cid;
      }
      else {
        cout << "Invalid entry. Object not added!" << "\n";
        return;
      }

      ClearInputStream(cin);

      gxBlockHeader request_header;
      request_header.block_length = sizeof(DatabaseObjectData);

      gxBlockHeader block_header;
      block_header.block_length = sizeof(DatabaseObjectData);

      if(client.ChangeBlock((char *)&dbobject, (char *)&new_dbobject_info,
    			request_header, block_header) != 0)
        cout << client.SocketExceptionMessage() << "\n";

      client.Close();
    }

    void ShutDownServer(int port, char *host)
    {
      gxStream client;
      if(client.StreamClient(port, host) != 0) {
        cout << client.SocketExceptionMessage() << "\n";
        client.Close();
        return;
      }

      cout << "Shutting down the server..." << "\n";
      if(client.TerminateConnection() != 0)
        cout << client.SocketExceptionMessage() << "\n";
      client.Close();
    }

    void FindObject(int port, char *host)
    {
      gxStream client;
      if(client.StreamClient(port, host) != 0) {
        cout << client.SocketExceptionMessage() << "\n";
        client.Close();
        return;
      }

      cout << "Searching the database" << "\n";
      DatabaseObjectData dbobject;
      ClearInputStream(cin);
      InputName("Enter the name of the object to find: ", dbobject);

      gxBlockHeader request_header;
      request_header.block_length = sizeof(DatabaseObjectData);
      gxBlockHeader requested_block_header;
      request_header.block_length = sizeof(DatabaseObjectData);

      DatabaseObjectData *p = \
        (DatabaseObjectData *)client.RequestBlock((char *)&dbobject,
    					      request_header,
    					      requested_block_header);
      if(!p) {
        cout << client.SocketExceptionMessage() << "\n";
        client.Close();
        return;
      }
      cout << "Server has answered request" << "\n";
      if(p->name[0] == 0) {
        cout << "The dbobject was not found in the database" << "\n";
      }
      else {
        cout << "Found the requested object: " << "\n";
        DisplayDatabaseObject(*(p));
      }

      delete p;
      client.Close();
    }

    int main(int argc, char **argv)
    {
      if(argc < 3) {
        cerr << "Usage: " << argv[0] << " hostname port" << "\n";
        return 1;
      }

      unsigned short port = (unsigned short) atoi(argv[2]);
      char *host = argv[1];

      char key;
      PrgMenu();
      int rv = 1;
      while(rv) {
        if (!cin) {
          ClearInputStream(cin);
          if (!cin) {
    	cout << "Input stream error" << "\n";
    	return 0;
          }
        }
        cout << '>';
        cin >> key;
        if (!cin) continue;
        switch(key) {
          case '?' : PrgMenu(); break;
          case 'h' : case 'H' : PrgMenu(); break;
          case 'q' : case 'Q' : rv = 0; break;

          case 'a' : case 'A' :
    	AddObject(port, host);
    	break;
          case 'c' : case 'C' :
    	ChangeObject(port, host);
    	break;
          case 'd' : case 'D' :
    	DeleteObject(port, host);
    	break;
          case 'f' : case 'F' :
    	FindObject(port, host);
    	break;
          case 'k' : case 'K' :
    	ShutDownServer(port, host);
    	break;
          default:
            cout << "Unrecognized command" << "\n";
        }
      }

      return 0;
    }
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