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Downloading and Storing Data. Using FTP and Other Services to Transfer and Store Data. Objectives. Learn what FTP is and how it works. Explore how to use an FTP client program and Web browser to transfer files. Navigate an FTP site using a Web browser.
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Downloading and Storing Data Using FTP and Other Services to Transfer and Store Data New Perspectives on the Internet, 4e Tutorial 6
Objectives • Learn what FTP is and how it works. • Explore how to use an FTP client program and Web browser to transfer files. • Navigate an FTP site using a Web browser. • Learn how to compress and decompress files and to check them for viruses. New Perspectives on the Internet, 4e Tutorial 6
Objectives • Download an FTP client program using a Web browser. • Download a compression program using an FTP client program. • Install and use a compression program. • Trace the connection between your computer and a remote computer. New Perspectives on the Internet, 4e Tutorial 6
Objectives • Explore storage options on the Internet. • Use Yahoo! Briefcase to upload and download a file. • Learn about emerging technologies for collaborative authoring on the Web. New Perspectives on the Internet, 4e Tutorial 6
UnderstandingFile Transfer Protocol • FTP, or File TransferProtocol, is the Internet protocol that transfers files between computers that are connected to the Internet. • The site to which you are sending files and from which you are receiving files is called an FTPsite, FTPserver, or a remotecomputer. • When you use your computer to connect to an FTP site, it is called the localcomputer. New Perspectives on the Internet, 4e Tutorial 6
UnderstandingFile Transfer Protocol • When you send a file using FTP, you upload the file to send it from your computer to the FTP site. • When you receive a file, you download the file from the FTP site and receive it on your computer. • You connect to a remote computer and request it to either receive files from your computer or transfer files to your computer. • FTP seamlessly transfers files between different operating systems. New Perspectives on the Internet, 4e Tutorial 6
File Transfer Modes • You can select one of two file transfer modes—ASCII or binary—that you want to use before transferring the file. • ASCII text contains symbols typed from the keyboard but does not include any nonprintable, binary codes. • Many files such as pictures, movies, sound files, and graphics are binary. • Choose ASCIImode to transfer plain-text files. • Choose binarymode for transferring everything else. New Perspectives on the Internet, 4e Tutorial 6
File Types and Extensions • The decision to transfer a file using binary or ASCII mode is largely determined by noting the file’s type. The file type can be determined by its extension. • A file extension is the last three characters following the period in the filename. • You can download files with a file extension of .txt in ASCIImode. • You should download files with other file extensions (.doc, .xls, etc.) in binarymode. New Perspectives on the Internet, 4e Tutorial 6
File Types and Extensions New Perspectives on the Internet, 4e Tutorial 6
Connecting to an FTP Server • To transfer files between your computer and a remote computer, you must first connect to the remote computer. • You can connect to a remote computer by logging on to it using an FTP client program or your Web browser. • Some FTP client programs and browsers will select the file transfer mode of binary or ASCII automatically. New Perspectives on the Internet, 4e Tutorial 6
FTP Using an FTPClient Program • An FTP client program resides on your PC and transfers files between your computer and an FTP site. • Most FTP client programs have menu bars or toolbars to help you execute commands. • FTP client programs transfer files quickly and provide features that let you resume downloading a file when your connection is lost or interrupted. New Perspectives on the Internet, 4e Tutorial 6
contents of the user's local computer contents of the remote computer toolbar FTP Using an FTPClient Program New Perspectives on the Internet, 4e Tutorial 6
FTP Using an FTPClient Program • When selecting an FTP client program, choose one that supports all or most of the following desirable features: • Multipane display showing both the local & remote computer directories. • Allows you to transfer multiple files in one FTP session. • Permits drag and drop file transfers. • Simplifies the process of deleting directories on local and remote computers. New Perspectives on the Internet, 4e Tutorial 6
FTP Using an FTPClient Program • (continued) • Allows you to transfer selected files unattended. • Recovers interrupted file transfers by continuing the transfer process from the point of interruption. • Reconnects automatically to sites that disconnect a transfer when your connection exceeds the maximum allotted time. New Perspectives on the Internet, 4e Tutorial 6
FTP Using a Web Browser • Most Web browsers, including Microsoft Internet Explorer and Netscape Navigator, 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, 4e Tutorial 6
URL for the FTP site appears in the browser's address field files on the site folders containingmore files FTP Using a Web Browser New Perspectives on the Internet, 4e Tutorial 6
Levels of Access for FTP Servers • To use a remote computer, you must identify yourself, or log on, by supplying your user name and password. • Public access: anyone can connect to the FTP site. Access is restricted to only those files and folders designated for access by public users. • Restricted access: do not allow public visitors. New Perspectives on the Internet, 4e Tutorial 6
Anonymous FTP • 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, 4e Tutorial 6
URL for the ftp site appears in the browser's address bar Anonymous user name Anonymous FTP New Perspectives on the Internet, 4e Tutorial 6
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, 4e Tutorial 6
Full-Privilege FTP • Full-privilege FTP: an FTP site that is not public and requires a user name and password to access its content. • 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, 4e Tutorial 6
Using a Public Directory • Public directory (pub): the directory that some public FTP sites allow users with anonymous FTP access to view. • Webmaster: the title given to the manager of a website. • The webmaster 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, 4e Tutorial 6
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, 4e Tutorial 6
root directory ftp.ibiblio.org incoming pub unc readme.txt archives docs multimedia readme.txt misc readme.txt readme.txt history.doc misc.doc Using a Web Browserto Navigate an FTP Site New Perspectives on the Internet, 4e Tutorial 6
Using a Web Browserto Navigate an FTP Site • An FTP site usually stores directories (folders) and files. • Double-clicking a file either opens the file in a new browser window or in a program window so you can view the file, or it begins downloading the file to your computer. • Double-clicking a folder opens the folder and displays its contents. New Perspectives on the Internet, 4e Tutorial 6
click this link to moveup one directory directory files folders withextensions (suchas .exe) are files Using a Web Browserto Navigate an FTP Site New Perspectives on the Internet, 4e Tutorial 6
Checking Files for Viruses • Computer viruses pose a real and potentially costly threat to anyone using the Internet. • Computerviruses are programs that “infect” your computer and cause harm to your disk or programs. • You must know how to detect and eradicate viruses if you plan to download anything, including data, programs, or e-mail attachments. New Perspectives on the Internet, 4e Tutorial 6
Checking Files for Viruses • Virus detectionsoftware, also called antivirussoftware, regularly scans the files on your computer and files being downloaded to your computer. • Files are compared to a signature that known viruses carry. • A virussignature (also called a viruspattern or a virusdefinition) is a sequence (string) of characters that is always present in a particular virus. • When the virusdetectionprogram finds a virussignature, it warns you. You can either delete the file or ask the virusdetectionprogram to remove the virus. New Perspectives on the Internet, 4e Tutorial 6
Checking Files for Viruses • Two popular choices for protecting PCs are Norton AntiVirus and McAfeeVirusScan. • 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, 4e Tutorial 6
Visiting and Using aDownload Site • A good way of locating software on the Internet is to use one or more Internet search engines. • 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, 4e Tutorial 6
Downloading Programs • Freeware: software that is available to users at no cost and with no restrictions. • Users must accept the implicit or explicit warning that the software might contain bugs. • Bugs: errors sometimes contained in freeware due to limited testing of the software. • A lot of good-quality commercial software started as freeware. New Perspectives on the Internet, 4e Tutorial 6
Downloading Programs • Shareware: similar to freeware, but it is usually available for free during a short evaluation period. • After the evaluation expires, shareware stops functioning. • Users are expected to stop using the shareware 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. • Shareware is 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, 4e Tutorial 6
Downloading Programs • There are three popular ways to turn shareware users into paying customers: • Build a counter into the program • Insert an internal date checker • Use a “nag” screen that appears each time you start the program New Perspectives on the Internet, 4e Tutorial 6
Downloading Programs • Limited Edition (LE): a restricted version of a shareware 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 limitededition version and use it for free. New Perspectives on the Internet, 4e Tutorial 6
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 amount of traffic at the FTP site. • 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 viruses. • After installing any program, you can delete the downloaded files from the drive and folder to which you downloaded it, or you can keep it in case you need to reinstall the program. New Perspectives on the Internet, 4e Tutorial 6
WS_FTPLE.exefile is selected Save button Using a Web Browser to Download an FTP Client Program New Perspectives on the Internet, 4e Tutorial 6
Using an FTP Client to 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. • When you use an FTP client program to save a site’s address and your user name and password, you are creating an FTP session profile. New Perspectives on the Internet, 4e Tutorial 6
Using an FTP Client to Download WinZip • Log on to the remote computer by supplying its URL, your user name or anonymous, and your password. • Navigate to the file you want to download. • Click the filename on the remote computer to select it. • Select binary or ASCII transmission mode. • Execute the command that downloads the file from the FTP site to your computer and end the FTP session by disconnecting from the remote computer. New Perspectives on the Internet, 4e Tutorial 6
Compressing andDecompressing Files • Internet files of all types are frequently stored in compressedform. • Compressedfiles use less space when stored and they take less time to be transferred from one computer to another. • You can use a filecompressionprogram to decrease the original size of most files. • After you download a compressedfile, you must use a program to restore the file to its original state before you can open or execute it. New Perspectives on the Internet, 4e Tutorial 6
Compressing andDecompressing Files • The process of restoring a compressed file to its original state is called file decompression, or fileexpansion. • FTP recognizes most compressed files by their extensions. • The most common extension is .zip, which is why some people refer to compressed files as zipfiles or a ziparchive. • If you download a compressedfile, you must have a filecompressionprogram installed on your computer to view its contents. New Perspectives on the Internet, 4e Tutorial 6
folder structure saved in the compressed file files in thecompressed file location in whichto extract the files option to extractthe folder structure user's localsystem Compressing andDecompressing Files New Perspectives on the Internet, 4e Tutorial 6
Tracing an Internet Route • Mirror site: a replica of an existing server that provides an alternate location for downloading files. • The distance between your PC and a remote computer on the Internet is measured in hops. • Hop: a connection between two connections. • You can count the hops and identify the computers between your PC and a remote computer using the Windowstracert (for traceroute) program. New Perspectives on the Internet, 4e Tutorial 6
Tracing an Internet Route • You can use the tracert program to make an informed choice when selecting a download site. • Tracert will show you up to 30 hops and indicate the response time, the site name, and the IP address of each hop along the route. • Ping(Packet Internet Groper): a program that tests a computer to determine if it is connected to the Internet. New Perspectives on the Internet, 4e Tutorial 6
tracert commandwill trace the route from FTP site to the local computer “Trace complete” message hops (your list will differ) Tracing an Internet Route New Perspectives on the Internet, 4e Tutorial 6
Using Online Storage Services • When you use an ISP for your Internet connection and e-mail 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 three or more megabytes of storage space on their servers, either free or for a fee, creating a new business model. New Perspectives on the Internet, 4e Tutorial 6
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 businesses rely on online storage services to send and receive large files while employees are traveling or as a normal course of business. New Perspectives on the Internet, 4e Tutorial 6
Using Online Storage Services • Many individuals use online storage services to store computer backup files, collections of sound files, personal Web sites, and other data. • 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, 4e Tutorial 6
links for learningabout xdrive servicesand features Online Storage Providers • Some popular online storage providers are: • Xdrive Technologies • My Docs Online • Yahoo! Briefcase New Perspectives on the Internet, 4e Tutorial 6
Yahoo! Briefcase • To use Yahoo! Services, you must have a Yahoo! account. • You can upload one file or multiple files to the default folders in your Briefcase, or you can use Briefcase to create new folders. • Folders may be public (all users can access it), private (no other users can access it), or friends (only specified users can access it). New Perspectives on the Internet, 4e Tutorial 6
Sending an E-Mail MessageLinked to a File in the Briefcase • You make other users aware of files you have uploaded to Briefcase by selecting it and then sending an e-mail message from Briefcase to the users’ e-mail addresses. • You can select more than one file per message and up to 10 e-mail addresses at a time to which to send the message. • You can include a personal note in the message. Yahoo! adds the name and description of the file in the message, along with the URL to download it. New Perspectives on the Internet, 4e Tutorial 6