Cross Platform File Transfer Via FTP and Web Browser

By Jay H. Burgherr, ACI Technical Support

Technical Note 97-3

Technical Notes for 97-01-02-January/February 1997

Many corporations recently have been looking at their desktop computer strategies and have decided to focus their Information Systems budgets on a single platform. When this happens, developers and database administrators may be required to look for a different platform for their 4D Server application.

Fortunately, 4D's well known cross platform capability makes this type of transition easy. However, many of the mission critical databases in use today have very large structures and data files. How do you transfer these large files quickly? An answer is via your ethernet—TCP/IP is a common networking protocol for both Macintosh and Microsoft Windows platform computers. With the use of FTP services software and a Web browser, you can transfer your data and structure to the new computer.

In this Technical Note we will discuss how to:

Set up FTP Services on the Macintosh

Set up FTP Services on Windows 95

Set up FTP Services on Windows NT 3.51

Set up FTP Services on Windows NT 4.0

Set MIME file types on Netscape Navigator

Download 4D Files using a browser as a FTP Client

FTP services are not part of the Macintosh OS at the time of this writing. However, a well designed, inexpensive shareware application, "NetPresenz" by Peter Lewis, is available on the World Wide Web. This application provides many TCP/IP and Web services/utilities, including an FTP file server. The FTP file server uses the Macintosh Apple Share settings to provide privileges to those who log in via FTP.

For the purposes of this Technical Note, file and directory read privileges are will be provided to any anonymous guest that connects to the computer. This is not necessarily a very secure environment for your files on the Macintosh. You may consider setting up more security on your production server. Instructions are provided in the NetPresenz documentation.

This Technical Note also assumes that your Macintosh has the TCP/IP protocol correctly installed and the computer is capable of 'pinging' other computers on the network, including the computer to which you will transfer the database.

1. Download the software from via the World Wide Web using a web browser. The URL for obtaining NetPresenz at the time of this writing is

ftp://ftp.share.com/pub/peterlewis/netpresenz-401.sit.bin.

This file is compacted and binary MIME encoded. Most current web browsers have helper utilities to decompress and decode this file.

2. Register your software as appropriate.

1. Double-click the NetPresenz Setup icon.

2. Click the FTP Setup button in the toolbar.

3. Set up the following screen as shown.

4. Click the Save button.

1. Click the FTP Users button on the toolbar.

2. Configure the screen as shown.

3. Click the Save button.

4. Go to the Control Panel in the Apple pull down menu.

5. Select Users & Groups.

6. Double click the Guest icon.

7. Click the "Allow guest to connect" check box.

8. Close the windows, saving the user configuration.

1. Go to the Sharing Setup Control Panel in the Apple pull down menu.

2. Click the File Sharing Start button.

3. Close the window.

4. From the desktop, select the hard drive that you wish to share.

5. Select Sharing from the File pull down menu.

6. Configure the privileges as shown.

7. Close the window.

8. In the next dialog, click Save to save the privileges.

9. In the next dialog, click OK to confirm that you want to change the privileges on all included folders.

10. Double-click the NetPresenz icon to start the FTP File services. Your Macintosh is ready to serve files via FTP.

Like Apple's Macintosh OS, Windows 95 does not have built in FTP services. However many third party companies have developed solutions to fulfill this need. We will show how to configure WFTPD by Texas Imperial Software, a shareware solution available on the World Wide Web. This application, like NetPresenz for the Macintosh, is easy to configure and works well.

Again, we assume that your Windows 95 computer has the TCP/IP protocol correctly installed and that the computer is capable of "pinging" other computers on the network, including the computer to which you will transfer the database. Also, the same caveats apply to the security issues of allowing anonymous connections to your computer.

1. Download the software from via the World Wide Web using a web browser. At the time of this writing, the URL is http://www.zdnet.com. From this URL you must perform a search for the WFTPD.

This file is compacted by PKZip. Most current web browsers have helper utilities to decompress and decode this file.

2. Register the software as appropriate.

3. From the Windows 95 Explorer, launch the file "Wftpd.exe."

4. Select "General..."from the Security pull down menu.

5. Configure screen as shown.

6. Click the OK button. Your Windows 95 computer is ready to serve files via FTP.

Microsoft Windows NT has FTP server services included on the installation diskettes or CD. Again, we assume that your Windows 95 computer has the TCP/IP protocol correctly installed and that the computer is capable of "pinging" other computers on the network, including the computer to which you will transfer the database. Also, the same caveats apply to the security issues of allowing anonymous connections to your computer.

To set up the FTP server in Windows NT 3.51:

1. Open the control panel.

2. Double click the Network icon.

3. In the next dialog box, click the Add Software button. The Add Network software dialog box appears.

4. Select "TCP/IP Protocol and related components," then click Continue. The Windows TCP/IP Installation Options dialog box appears.

5. Click the FTP Server Service check box. Then click the Continue button.

6. Provide the installer with the directory of the Windows NT workstation files for Intel platform computers. If the CD ROM drive is designated as your D: drive, the path would be "D:\i386."

7. A dialog appears, stating that any password sent to this server will not be encrypted and could be intercepted by someone on the network. Click the Yes button.

8. Declare the Starting directory that will be presented to anyone who logs into the FTP server. In most cases, the root directory of C: is preferred. Click the check box "Allow Anonymous Connections."

9. Click the OK button.

10. After the new software is loaded, a dialog will notify you that the software has been loaded and you should restart the system. Make sure that all of your applications are closed and documents save. Click the Restart Now button.

11. When the computer completes restarting, Windows NT 3.51 is ready to serve files via FTP.

Microsoft's newest version of Windows NT (4.0) includes FTP Server Services. Microsoft has changed the naming conventions for this version of Windows. The FTP Server set up is located in "Peer Web Services."

Like all of the above configurations, the set up shown in this Technical Note assumes that TCP/IP is set up correctly. This configuration also provides very little security for your files. You may wish to investigate setting up a higher level of security for your proprietary files.

1. From the Start button, select Control Panel.

2. Double-click the Network icon in the Control Panel.

3. Select the Services tab in the Network properties window.

4. Click the Add... button.

5. Select Microsoft Peer Web Services.

6. Click OK.

7. Insert the NT 4.0 CD into the CD-ROM drive.

8. Provide the directory where the NT 4.0 files are located for Intel platform computers. If your CD-ROM drive is configured as D:, you would enter "C:\i386"

9. Click OK.

10. Click OK to accept the copyright dialog.

11. Configure the following screen as shown.

12. Click OK.

13. In the next dialog, enter the path for the default directory. For most purposes, C:\ is preferred.

14. Click OK.

15. Click the OK button on the next screen, which reports the FTP Server has been successfully installed.

16. Windows NT 4.0 is ready to serve files via FTP.

A MIME (Multipurpose Internet Mail Extension) extension tells your web browser what to do with a file that is downloaded. In the case of a file that has been compressed with PKZip, the MIME extension is ".zip." When a MIME compliant browser downloads a file with this extension, it automatically launches PKUnZip to decompress the file. In the case of transferring and saving 4D structures, data files, and other associated 4D files, a new MIME type must be configured.

For the purposes of this Technical Note, we will configure Netscape Navigator and use it as the FTP Client. Microsoft's Internet Explorer and other browsers can also be configured for custom MIME types.

1. Start Netscape Navigator by double clicking its icon.

2. Select General Preferences... from the Options pull down menu.

3. In the Preferences window, click the Helpers tab to present the Helpers Perference options.

4. In the Helpers tab window, click the Create New Type... button. A new window appears, titled Configure New Mime Type. In the Mime Type: field of the new window, enter "application." In the Mime Sub Type: field, enter "4D-Database." Then click OK.

5. In the File Extensions: field, of the Helpers tab window, enter the list of extensions used by 4D.

6. Click the Save to Disk radio button.

7. Click the OK button.

8. Your Netscape Navigator browser is ready to receive 4D files via FTP.

Now that the FTP Server and Browser are configured, it is easy to download 4D Files from one platform to another. For this demonstration, we will use the 4D Airlines database and transport it from the Macintosh to the Windows NT 4.0 platform.

In this example, we will assume that the structure file, data file, and externals have all been passed through 4D Transporter. We will also assume that the Macintosh has NetPresenz correctly installed, configured and launched. As for the Windows platform, we assume that Netscape Navigator has been installed and the new MIME type configuration entries for 4D files have been made.

1. Start Netscape Navigator on the Windows computer.

2. Enter the TCP/IP address of the server to which you are connecting, in the following format: ftp://100.100.100.31/ (replace the "100.100.100.31" with the IP address of your server). A window of the root directory (folder) of the Macintosh will appear on your browser screen.

3. Navigate to the directory/folder that contains the 4D structure file, data file, and supporting files (externals) by clicking on the folder that you want to open.

4. To start the transfer of a file from the FTP Server to your computer, click on the file that you wish to retrieve.

5. A dialog will be displayed that will allow you to direct the browser to where you wish to save the file locally. Click the Save button. The transfer will begin immediately.

You have successfully completed a cross platform file transfer via FTP using a web browser.

In this Technical Note we have shown:

1. How to set up FTP Services on the Macintosh

2. How to set up FTP Services on Windows 95

3. How to set up FTP Services on Windows NT 3.51

4. How to set up FTP Services on Windows NT 4.0

5. How to set MIME file types on Netscape Navigator

6. How to download 4D Files using a browser as a FTP Client