File Transfer Protocol (FTP)

Think of the TCP/IP software as the basic transportation device -- the "automobile," if you will -- and the other programs you use as the "accessories," the add-ons for that "car."

When you buy a new car, you add special accessories to perform special tasks.

For instance, you could roll the window down to cool off, of course, but most people select an air conditioner to make them more comfortable.

Or you could have your passengers sing for entertainment, but most people instead add a radio/tape/CD player these days.

You could carry kindling, logs, matches, and a blanket in the trunk for sending smoke signals if you break down, but many new car buyers opt for a CB radio or a cellular phone to call for help if they need roadside assistance.

By the same logic, when you make your new connection with the Internet, there are specialized tools you can get to perform -- and streamline -- individual tasks. There are tools to connect to other computers as a terminal (Telnet), tools to search the 'Net (Archie, Gopher, Web browsers), and tools for retrieving files and programs that are found (FTP).

The others will be covered by later lessons. In this session we consider the latter -- FTP.

"Well, that certainly cleared things right up! What the heck does File Transfer Whachamacallit mean?"

Let's take it a step at a time. Suppose you find a file on the Internet you want, perhaps a glossary of computer terms. You want to transfer that file to your computer. You need a program which will be able to establis h the correct transfer protocol so your computer and the remote computer (the one with the file you want) can speak the same language.

There are some programs that will do a little of everything, sort of like a Swiss Army Knife. Netscape, for example, does a little mail, a little FTP, a little Gophering, and so forth. Of course, you can drive a nail wi th a bowling ball, but it isn't necessarily the most efficient tool for the process.

FTP programs do one thing -- transfer files -- and they do it well. In the Unix shell, the programs of choice are FTP and NCFTP. On the PC, some of the better programs are CuteFTP and WSFTP. On the Mac, one of the standard FTP programs is Fetch.

UNIX:

In Unix, entering FTP or NCFTP will produce a prompt like this:

ftp> or
ncftp>

At the prompt, you enter:

open

The program will then prompt you for the URL ("Uniform Resource Locator"), a fancy term for the address of the computer you want to contact, also known as the host. This is usually entered as:

ftp.destination.com

This will make connection with the remote host and allow you to log in. If you have an account -- that is an ID and password -- on the remote host, enter it when prompted. If you don't, but are entering the host as a guest, you will do what is called an anonymous file transfer.

At the "Login:" prompt, enter:

anonymous

At the "Password:" prompt, enter:

your.email.address (such as mbowen@nando.net)

This normally puts you in the topmost public FTP directory. You can navigate down to the one you want by entering:

cd directoryname

Once you find the directory you're seeking and the file you want, enter:

get filename

This will transfer the desired file to your home directory in Unix. It is a simple matter to then download it to your own computer.

[TIP: When retrieving an applications -- or program -- file, it must always transferred in "binary" mode. If not, it will not run when expanded on your computer. Text will come across equally well if transferred as either "text" or "binary." Therefore it is a good idea to get into the habit of transferring ALL files as "binary." This is done by typing binary before the "get" command above. Most SLIP/PPP FTP clients either automatically select or use "binary" mode for all transfers.]

To end an FTP session, at any system prompt, enter:

bye

[TIP: NCFTP has a number of advantages over its older sister, FTP. For one, when you tell it to "open" a session, it give you a handy list of all the sites you have gone to before and allows you to pick one merely by entering the num ber beside the previous address. Then it contacts the remote computer, logs you on automatically as "anonymous," then actually remembers the subdirectory you were in before and places you direcftly back into that one! Not every program is that smart.]

[TIP: Text files, such as FAQs (Frequently Asked Questions) can be transferred as "text," but program files MUST be transferred as "binary" files, to retain their structural integrity and allow them to be run when they are in stalled. Since transferring text files in binary format will not harm them, you might want to transfer everything as binary. Simply enter "binary" at the prompt before issuing the "get" command.]

SLIP/PPP:

The programs used with the SLIP/PPP connection will normally ask you to set up a "session profile" -- that is, a connection file which can be brought up each time you want to connect to the same site, much like NCFTP. Here you will enter a name for the p rofile (this can be anything that will help you remember the site), the host name (the name of the remoter computer you are calling), and whether you have an ID and password on the remote host or whether you want to make an anonym ous connection. There is usually also a place to enter the remote directory (the one you want to be in on the computer you are calling) and the local directory (the one you want to copy files from or to on your own system).

In order to transfer files in either direction, you merely click the mouse on the file to highlight it, then select the arrow pointing to the machine to which it is to be copied.

It's as simple as that!

To end the session, you merely exit the program.

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