Hopkins in Cyberspace By Mike Field Would you like to have a copy of the U.S. Constitution tucked away in your computer's memory, just in case you ever need it? How about the Koran or the Bible or the NATO handbook? Or perhaps you'd like to download software such as Mosaic to access World Wide Web, or any one of about a thousand other computer programs and games. All these and much, much more are available through your connection to the Internet. To access them, you need to master the trick of moving files. The tool for doing this is ftp, shorthand for file transfer protocol. Most any computer with full connectivity to the Internet (that is, more than just e-mail) can be set up to ftp; however, not all Internet-connected computers necessarily have the requisite software installed to ftp. Finding out whether your computer is so equipped is relatively easy. Mac and Windows users will have an FTP icon on their main screen and will need to click on them to begin; others can initiate an ftp session by typing ftp at the system's command line. In broad strokes, the whole ftp process is a relatively straightforward series of actions in which a computer user starts the ftp program, gives it an Internet address to go to, signs on to that system, finds the desired information, retrieves it and signs off. In reality of course, the actual practicalities of such an operation are often more complex--and more confusing-- than first meets the eye. For instance, many computers on the Internet are inaccessible to all but those registered and assigned passwords. For our purposes we will use anonymous ftp, so called because the site we visit will not know us in advance. Many computers on the Internet allow anonymous access. A fairly complete list of anonymous ftp sites can be found at ftp.shsu.edu, following the path /pub/doc/doc-net/ftp-list/sitelist (more on this later). Note: If you wish to try your hand at ftp by following this example, try to do so during non-working hours to help avoid Internet overload. Let's say that from an Internet-savvy source we have learned the U.S. Constitution and other significant historical documents are available online at ftp.spies.com. Now we want to retrieve one of these documents. At the command line type ftp followed by a space and then the address: ftp.spies. com. (That's right, in this particular example the second ftp is part of the address. Not all ftp sites are so named.) In Windows or Mac, click the ftp icon, then enter the address at the line marked "host name." Be sure you are set up as "anonymous" in your user ID line. When you hit the enter key, assuming you connect successfully, a string of information provided by the server (that's the remote computer) appears on the screen, ending with "USER (identify yourself to the host):" Here's where anonymous ftp proves so useful. Even though the server doesn't know us, some, including this one, will let us in for limited access. To see if this computer is stranger-friendly, type "anonymous" at the prompt. Once again we receive a string of information, this time ending with "Guest login ok, send your complete e-mail address as password," followed on the next line by "Password:" At this juncture, type in your complete e-mail address as a courtesy to the host computer. Here follows another batch of information including, most likely, welcoming information. It ends with the simple line "Command:" or in this case, "ftp>". Now here is where things begin to get tricky. On most (but not all) ftp clients (that is, the software you are running through your machine) typing "dir" (without the quotations) will call up the server's directory. On Windows and Mac this process is even easier, requiring only the click of a mouse. If dir doesn't work, try typing "help." Calling up the directory is key to maneuvering around this new host computer. After all, we've never been here before, so the only way to get familiar with the place is to look around. What we will typically find is a mixed directory containing some sub-directories (identified by the letter "d" at the beginning of the descriptive line) and files (identified by a dash "-" at the same place). The word that occurs at the end of the line is the name of the file or directory. We will find the Constitution in the directory marked "Gov" under the sub-directory "US-History." Having visited the site and seen some of what's there, it's time to go home. Type "bye" at the prompt line to sign off. Next week, we will transfer a file from the server to our own computer.
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