File Transfer Protocol (FTP) is a protocol used to transfer ASCII or BINARY files between two computers on the Internet. The primary function of FTP on the Internet is in the use of anonymous FTP sites. An anonymous FTP site is simply an Internet site accessed via FTP that has a large number of files available for downloading. They are called anonymous because you login anonymously. Simply enter the word anonymous at the "Name:" prompt and your full e-mail address at the "Password:" prompt.
Some anonymous FTP sites are small, consisting of only a dozen or so files related to a specific topic. Others are huge shareware archives with thousands of files. It should be noted that the increasing influence of the World Wide Web has resulted in most file archives being available over the Web, as well as FTP.
FTP Clients
To directly access an FTP site on the Internet, you will need some kind of FTP client. While most Web browsers have built-in FTP clients, stand-alone FTP applications also exist. Having such an application is an advantage if you don't like waiting for your web browser to load when all you want to do is access an FTP site.
Archie File Search
Because there are so many anonymous FTP sites on the Internet, it would be impossible for you to search through each one individually in hopes of finding the file you want. To assist you in your file search, a service called Archie is available. Archie is a public search engine whose database currently maintains a list of about 900 Internet anonymous FTP sites of approximately 2.1 million files containing 170 Gigabytes (170,000,000,000 bytes) of information.
There are many Archie servers throughout the world that can be accessed either by e-mail or telnet. None of these servers actually store all of the files available via anonymous FTP. Instead, they simply keep track of the directories and filenames located at each anonymous FTP site.
Types of Searches
Name Searches
To perform a name search, simply give Archie a search string (there are four search formats, discussed below). Archie will then list all FTP sites that have the word(s) you're searching for in their directories or filenames. For example, if you searched for the word "equestrian," you might receive the following result:
Host plaza.aarnet.edu.au
Location: /usenet/FAQs
DIRECTORY drwxr-xr-x 512 15-May-1996 16:53:25 rec.equestrian
Host sun.rediris.es
Location: /docs/faq/rec
DIRECTORY drwxr-xr-x 512 05-Mar-1996 15:07:17 equestrian
Host ucdavis.ucdavis.edu
Location: /pub/U.C.Davis.directory/Campus.Departments.and.Offices/E
FILE -rw-r--r-- 122 29-Oct-1995 10:44:02 EQUESTRIAN.CENTER........................................752-2372
We now know that what appears to be a UseNet FAQ for the newsgroup rec.equestrian can be downloaded via anonymous FTP from the FTP site plaza.aarnet.edu.au, among others. The third result (from ucdavis.ucdavis.edu) appears to be part of an e-mail directory.
As previously mentioned, there are four ways of entering a search string for an Archie name search. A brief description of each is as follows:
Archie maintains a Public Domain Software Description Database, which contains descriptive information about the actual content of some files (mostly text files) that can be downloaded via anonymous FTP. This type of search is most useful if you're trying to find information about RFC's, Unix utilities, or technical Internet documents.
Site Searches
Two commands fall under ths category. The list command results in a list of all anonymous FTP sites currently in Archie's database. The site command produces a list of all files known to Archie for a specific FTP site.
How to Access Archie
There are many Archie servers located throughout the world. Each can be accessed several different ways. You can perform an interactive Archie search by logging into an Archie site via telnet or by using an Archie client. A remote Archie search can be done by using e-mail. Each of these methods is discussed below:
Archie Client
This is perhaps the easiest way of using Archie for anyone with a SLIP/PPP Account. An Archie client is a piece of software that automatically telnets to your favorite Archie server, enters the proper commands, and neatly displays the results on your screen. Most programs allow you to automatically download any file in the Archie result screen using your FTP Client.
Telnet to Archie
Accessing Archie via telnet is probably one of the most difficult ways of getting things done, but a brief explanation of how to go about it has been included just in case. The first step is to telnet to one of the Archie servers. A good rule of thumb is to pick the one that is geographically closest to your location. Once you are connected to the server, simply enter the word archie at the login prompt (login:). No password is necessary. You will then receive a prompt that looks like this: archie:.
The appearance of this prompt marks the beginning of your interactive Archie session. At this point, you can enter any of the commands accepted by Archie. Although a complete Archie operation manual is available, a brief summary of the essential commands is listed below:
Accessing Archie by E-Mail
Because Archie is used quite frequently by the Internet community, you will often find that using Archie interactively is rather sluggish. This is because you are always in line behind others trying to use the same Archie system. So, let's say you just want a quicker way to search Archie's database. Or, perhaps you only have access to e-mail and can't use Archie using any of the other methods. There's a simple solution to both of these problems -- access Archie by e-mail!
All you have to do is simply send an e-mail message to the Archie server of your choice, and the next time you check your e-mail (the process usually takes a few minutes, although it can sometimes take as much as a day), you will have an e-mail message from Archie with all the results from your search. To use Archie via e-mail, follow these steps:
This process is done using a listserver and is completely automatic. In other words, no humans are involved in this process, so any problems you encounter are due to problems with the Archie server. A complete list of Archie commands that can be used is available.
Search For Anonymous FTP Sites on the Web
With the increasing influence of the World Wide Web on the Internet, many anonymous FTP sites now have their entire file archies available on the Web. Most of these also have easy-to-use search engines that search file names and (sometimes) file descriptions for an entered search pattern. A useful service called Shareware.com (http://www.shareware.com) can be used to search several of the existing on-line FTP sites at once.