Tutorial 5 Downloading and Storing Data

1. Tutorial 5Downloading and Storing Data

2. Objectives • Learn what FTP is and how it works • Explore how to use a Web browser to transfer files • Navigate an FTP site using a Web browser • Learn about checking downloaded files for viruses and other threats • Learn about types of download software New Perspectives on The Internet, Seventh Edition

3. Objectives • Evaluate download software for appropriateness and quality • Download an FTP client program using a Web browser • Download a compression program using an FTP client program • Learn how to compress and decompress files • Explore storage options on the Internet New Perspectives on The Internet, Seventh Edition

4. UnderstandingFile Transfer Protocol • FTP (File TransferProtocol): the Internet protocol that transfers files between computers connected to the Internet • FTPsite (FTPserver, remote computer, or remotesite): the site you are sending files to and receiving files from • Localcomputer or local site: your computer when you use it to connect to an FTP site New Perspectives on The Internet, Seventh Edition

5. UnderstandingFile Transfer Protocol • When you send a file using FTP, you upload the file to send it from your computer to the remote site • When you receive a file, you download the file from the remote site to your computer • FTP seamlessly transfers files between different operating systems New Perspectives on The Internet, Seventh Edition

6. File Transfer Modes • You can select one of two file transfer modes: • ASCII text: contains symbols typed from the keyboard but does not include any nonprintable, binary codes • Binary: files such as pictures, movies, sound files, and graphics • Choose ASCIImode to transfer plain-text files • Choose binarymode for transferring everything else New Perspectives on The Internet, Seventh Edition

7. File Types and Extensions • File extension: the characters following the period in the filename New Perspectives on The Internet, Seventh Edition

8. Logging on to an FTP Site Using a Web Browser • Most Web browsers, including Internet Explorer and Firefox, support FTP, but have limited functionality when compared to FTP client programs • To upload a file, you must drag it from your desktop or Windows Explorer and drop it in the correct location in the browser window • To download a file, you select the file to download and tell the browser where to save it on your computer New Perspectives on The Internet, Seventh Edition

9. Logging on to an FTP Site Using a Web Browser New Perspectives on The Internet, Seventh Edition

10. Anonymous FTP • To use a remote computer, you must identify yourself, or log on, by supplying your user name and password • Anonymous login: logging on to one of the many publicly accessible, remote computers connected to the Internet • You use anonymous as your user name • Anonymous FTP session: when you download or upload files using an anonymous login New Perspectives on The Internet, Seventh Edition

11. Anonymous FTP New Perspectives on The Internet, Seventh Edition

12. Anonymous FTP • Public FTP sites usually impose limits on uploading files or provide only one publicly accessible directory to which you can upload files • Access to selected files and directories is also limited • You should obey all rules and regulations regarding anonymous access • Look for the site’s acceptable use rules and policies in the readme.txt file in the pub (public) directory New Perspectives on The Internet, Seventh Edition

13. Full-Privilege FTP • Full-privilege FTP: FTP site access that requires a user name and password • The system might automatically direct you to a particular directory on the FTP site in which you have been given rights to upload and download files • You can usually store files for longer periods than you can on a public FTP site New Perspectives on The Internet, Seventh Edition

14. Using a Public Directory • Public directory (pub): the directory that some public FTP sites allow users with anonymous FTP access to view • Webmaster: • Title given to the manager of a website • Must monitor the files uploaded to a public directory on a regular basis to check for viruses and to find and delete any illegally uploaded files New Perspectives on The Internet, Seventh Edition

15. Using a Web Browserto Navigate an FTP Site • FTP sites are organized hierarchically, much like the folders and files on a computer’s hard drive • When you access an FTP site, you usually enter at the site’s root directory • Most sites prevent users with anonymous logins from accessing some files and directories in the root directory New Perspectives on The Internet, Seventh Edition

16. Using a Web Browserto Navigate an FTP Site New Perspectives on The Internet, Seventh Edition

17. Using a Web Browserto Navigate an FTP Site • An FTP site usually stores directories (folders) and files • Clicking a link to a directory opens the folder and displays its contents • Clicking the link to a filename opens the file and displays its contents • To download a file to your computer, right-click the filename to open the shortcut menu, click Save Target As, navigate to the drive and folder in which to save the file, and then click the Save button New Perspectives on The Internet, Seventh Edition

18. Using a Web Browserto Navigate an FTP Site New Perspectives on The Internet, Seventh Edition

19. Using a Web Browserto Navigate an FTP Site New Perspectives on The Internet, Seventh Edition

20. Checking Files for Viruses • Computerviruses are programs that “infect” your computer and cause harm to your disk or programs • Viruses pose a real and potentially costly threat to anyone using the Internet • You must know how to detect and eradicate viruses if you plan to download anything, including data, programs, instant messages, or email attachments New Perspectives on The Internet, Seventh Edition

21. Checking Files for Viruses • Antivirus program: • Regularly scans the files on your computer and files being downloaded to your computer • Files are compared to a signature that known viruses carry • Virussignature (viruspattern or virusdefinition): a sequence (string) of characters that is always present in a particular virus • When the antivirus program finds a virus signature, it warns you. You can either delete the file or ask the antivirus program to remove the virus New Perspectives on The Internet, Seventh Edition

22. Checking Files for Viruses • Three popular choices for protecting PCs are produced by Symantec (Norton), McAfee, and ZoneAlarm • Antivirus software must be turned on, properly configured, and include current virus patterns to protect your computer from viruses • You must regularly download virus patterns from the server to keep your computer safe • One of the best ways to protect your computer from viruses is to be careful about which files you download and the sources you use to get those files New Perspectives on The Internet, Seventh Edition

23. Checking Files for Viruses New Perspectives on The Internet, Seventh Edition

24. Types of Download Software • Many programs are available for download at little or no cost • Several Web sites provide links to freeware and shareware programs. Some of these same sites also allow you to download programs directly New Perspectives on The Internet, Seventh Edition

25. Types of Download Software • Freeware: software available to users at no cost and with no restrictions • Bugs: errors sometimes contained in freeware due to limited testing of the software • Users must accept the implicit or explicit warning that the software might contain bugs • A lot of good-quality commercial software started as freeware New Perspectives on The Internet, Seventh Edition

26. Types of Download Software • Shareware: • Similar to freeware, but it is usually available for free during a short evaluation period • After the evaluation expires, it stops functioning • Users are expected to stop using it after the specified initial trial period and uninstall it from their computers • Anyone who likes the program and wants to continue using it can purchase a license • Usually more reliable than freeware because the shareware developer is sometimes willing to accept responsibility for the program’s operation New Perspectives on The Internet, Seventh Edition

27. Types of Download Software • Limited Edition (LE) or Evaluation Version: • Restricted version of a program • Provides most of the functionality of the full version that is for sale • Omits one or more useful features of the full version • You can sometimes download a limited edition version and use it for free

28. Using a Web Browser to Download an FTP Client Program • Start your Web browser, and then open the Web site from which you will download the file • Navigate to the page that contains the file you want to download, and then click the link to the file • In Internet Explorer, click the Save button in the File Download dialog box, click the Browse Folders link (if necessary), navigate to the drive or folder in which to store the file, and then click the Save button If necessary, click the Close button to close the dialog box New Perspectives on The Internet, Seventh Edition

29. Using a Web Browser to Download an FTP Client Program • In Firefox, click the Save File button to download the file. Select the location in which to save the file (if available), click the Save it to disk option button (if necessary), and then click the OK button. Navigate to the drive or folder in which to store the file, and then click the Save button. Close the dialog box (if necessary). If the file is downloaded automatically to an existing folder or to the desktop, Close the Downloads dialog box, locate the file, and then cut and paste it to the drive and folder in which to store the file

30. Using a Web Browser to Download an FTP Client Program • The time it takes to transfer the program files varies based on the speed of your Internet connection and the file’s size • If you encounter problems while downloading a file, stop the process by clicking the Cancel button and try again later • After downloading anything from the Internet, your first priority is to scan the file for security threats New Perspectives on The Internet, Seventh Edition

31. Using an FTP Programto Download WinZip • File compression programs compress files to decrease the amount of space they require and also to decrease the time it takes to upload and download files • WinZip is a popular file compression program which is available for free during its evaluation period New Perspectives on The Internet, Seventh Edition

32. Using an FTP Program to Download WinZip • Log on to the remote site by supplying its URL, your user name or anonymous, and your password (if necessary) • Navigate to the file you want to download • Click the filename on the remote site to select it • Navigate to the drive or folder on your computer to which to download the file • Drag the file from the remote site to the drive or folder on your computer • End the FTP session by disconnecting from the remote site New Perspectives on The Internet, Seventh Edition

33. Compressing andDecompressing Files • Compressedfiles: use less space when stored and they take less time to be transferred from one computer to another • Filecompressionprogram: decreases the original size of most files • After you download a compressed file, you must use a program to restore the file to its original state before you can open or execute it • The process of restoring a compressed file to its original state is called file decompression or fileexpansion New Perspectives on The Internet, Seventh Edition

34. Compressing andDecompressing Files • FTP recognizes most compressed files by their extensions • The most common extension for compressed files is zip, which is why some people refer to compressed files as zipfiles or a ziparchive • If you download a compressed file, you must have a file compression program installed on your computer to view its contents New Perspectives on The Internet, Seventh Edition

35. Compressing andDecompressing Files New Perspectives on The Internet, Seventh Edition

36. Compressing andDecompressing Files New Perspectives on The Internet, Seventh Edition

37. Evaluating Online Storage Services • When you use an ISP for your Internet connection and email services, you might also receive some free space to use to store a Web site or files • Many services have evolved to meet the increased need for ways to store and share files. FTP sites are one way of sharing and storing files • ISPs and other entities have started providing storage space on their servers, either free or for a fee, creating a new business model New Perspectives on The Internet, Seventh Edition

38. Using Online Storage Services • Users access the online storage space using an FTP client program, a program or other interface provided by the provider, or a Web browser • The space is secured with an account name and password and permits the sharing of files by many users • Many individuals use these online storage services to store backup files, sound files, personal Web sites, pictures, and other data New Perspectives on The Internet, Seventh Edition

39. Using Online Storage Services • As a result of bandwidth problems, many online storage providers have changed their policies to limit the number of transfers and amount of space provided, to charge a small monthly fee for use of the space, or a combination of both • Some online storage providers come and go on a regular basis so it is important to backup important files and keep a copy of them locally New Perspectives on The Internet, Seventh Edition

40. Using Online Storage Services New Perspectives on The Internet, Seventh Edition

41. Summary • You can: • Use a Web browser and an FTP client program to transfer files on the Internet • Evaluate freeware, shareware, limited edition, and licensed programs • Use online storage providers to store files that you can share with other users New Perspectives on The Internet, Seventh Edition