Chapter
17
Getting Files with FTP
At this point, you've hit all the "big
ones" --World Wide Web, e-mail, Usenet. Now you know what all the fuss has been
about. But wait, you can still discover some lesser-known yet powerful tools. Next in line
is File Transfer Protocol, or FTP. Using FTP is one of the most popular methods of
obtaining software and documents on the Internet.
By the end of this lesson, you'll be able to answer
the following questions about FTP:
- What is FTP and how does it work?
- How do I access FTP sites?
- How do I get around FTP sites to get what I want?
- What is the best way to get the files I want?
- How do I actually download files?
Using the two most popular Web browsers, Netscape
and Internet Explorer (discussed in Lesson 14, "Netscape Versus Internet Explorer:
Finding the Right Browser"), you can FTP files right from a browser window. For added
functionality, however, you can obtain clients designed specifically for FTP (see Appendix
B, "Shareware Products for Windows").
FTP in a Nutshell
File Transfer Protocol. The phrase may sound
intimidating when you first hear it; however, it's really not. As you learned in Lesson 1,
"The Internet: What's It Really Like?" a protocol is nothing more than a set of
rules. Thus, FTP is nothing more than a set of rules for transferring files. Easy, eh?
But perhaps you want to know more about what FTP is
like. Hang on--the following section is for you.
What Is FTP?
Imagine, if you will, a super-library--one with
aisles of guides, videos, CDs, power tools, and everything else imaginable. Furthermore,
imagine that every time you check out a guide or other resource, another one pops on the
shelf to take its place. Now imagine no due dates, no library cards. Just browse and get
what you want.
But don't stop there. Imagine further that you can
contribute to the library yourself, providing materials that you have to offer for others,
as well. FTP is pretty much like that. Among the many machines on the Internet are some
that are dedicated to being electronic "libraries." Each library allows you to
upload or download files of text, graphics, and software tools that you can read, view,
and use on your home computer.
Just A Minute: Unlike a library, some of the
files available via FTP do cost a little. Files for which you pay some small fee are
usually called shareware programs (as opposed to free software, called freeware). The
authors of these programs "share" them for a small fee so that they can afford
to write even more. Still other software authors put out limited use demo software to
entice you to buy the complete product. Believe it or not, some of the best software in
the world started out as freeware and shareware.
FTP is a fast, efficient, and reliable way to
transfer information. It was one of the first Internet services developed to enable users
to transfer files from one place to another. This service is designed to enable you to
connect your local machine to a remote computer on the Internet, browse through the files
and programs that are available on the computer, and then retrieve those files to your
computer.
New Term: Local/Remote: You will see the
terms "local" and "remote" a lot in reference to FTP. A local machine
is your computer--after all, you can't get any more local than your desktop. A remote
machine is simply a server to which you connect via means of a modem or network
connection.
Where Is FTP?
The servers that keep all these files for you are
commonly called FTP sites. Each site is its own self-contained electronic library
containing information, files, and applications on every topic imaginable. You don't
really take files from FTP sites, though; you transfer them from the FTP site to your own
computer.
An unfathomable amount of information is available
on FTP sites--trillions and trillions of bytes worth. Some basic types of information are
briefly mentioned here; for more information on what these files are called, refer to the
section titled "Names: The File Frontier."
- Text files: Text files of infinite variety are
available via FTP. Get a copy of the lyrics to your favorite Bob Dylan song, grab a copy
of Alice in Wonderland, or peruse the latest wisdom on good manners on the Internet.
- Multimedia files: Pictures, 3-D renderings,
stereograms (you know, those things you have to stare at for 45 seconds before you can see
them?), even movie clips are available with FTP, too.
- Applications: From e-mail clients to programs that
help you balance your checkguide, they're all there. Software of every type, flavor, and
color is available with FTP.
Of course, hundreds of variations of these three
basic categories do exist, but I hope that this list gives you an idea of the types of
resources to which FTP gives you instant access.
Anonymous FTP
Unfortunately, as great as much of the information
is, it's not always available to everybody. Many FTP sites are set up for a specific
purpose or for a particular group of users. This limited purpose succeeds in somewhat
restricting the access to some of the resources that are available via FTP.
The good news is that lots and lots of sites are
available to everybody. These sites are called anonymous FTP sites. They are called
"anonymous" because they don't require you to identify yourself in order to gain
access to the site. Rather, you're invited in as a "guest" to browse and
retrieve files as you want.
Just A Minute: Just because an FTP site is an
anonymous site does not necessarily mean that it has unlimited access. A site may limit
the number of anonymous users during business hours, restrict anonymous users to
particular areas, require that you enter your e-mail address as a password, or not allow
for the download of certain files from the site, as you can see in Figure 17.1. So keep in
mind that free instant access may not let you take all the candy in the candy store when
you want to take it.
Figure 17.1.
Many FTP sites restrict use to certain times of
the day and to a particular number of users.
The wide range of files on anonymous FTP sites means
that something really is available for everyone. From novices to experienced programmers,
you can find something for you.
Just A Minute: Not all FTP is anonymous. Many
times you may have access to an FTP server that requires a valid user name and password.
Logging on to these is simple: Just use your system user ID as your login (provided by
your system administrator) and your password. After you've logged on, using FTP this way
is identical to using FTP anonymously.
FTP Structure and Syntax
Before you can download anything from an FTP site,
you must first get onto a site and then know how it is structured. When doing so, you need
to know three basic pieces of information: the site name, the directory path of the file
you want, and the actual name of the file.
Time Saver: Often, you may not know the
specific location of the file you're looking for. Usually, you can conduct a search on the
Internet. You can find an excellent place to search for software on the Internet at http://www.shareware.com/. For more
specifics on searching for files on FTP, refer to Lesson 20, " Finding People,
Places, and Things on the Net."
You already learned about domain names in many
previous lessons. FTP site names generally (but not always) begin with ftp. As
you also know, the protocol portion of an FTP URL is ftp://.
Whether you're using a Web browser or an actual FTP
client, you shouldn't have any problem getting on. Just remember, if your client asks for
a user ID or login ID and password to get onto a site, just use anonymous as your
user ID and your@email.address as your password, as shown in Figure 17.2.
Figure 17.2.
With most FTP clients, like WS_FTP, you can enter
all relevant information before getting on a site.
Like a Tree
The second element you need to know is the directory
path of the file you want. Directory paths are much like the branches of a tree with each
subdirectory "branching" off from a previous one. If you were to climb a tree,
for example, you would start at the trunk, climb on a branch, then move out on a limb, and
so on.
FTP sites are the same. The "trunk" of the
FTP site is called, not coincidentally, the root directory. From this directory, you
choose the branch directories (called subdirectories) from the root directory. Figure 17.3
shows a simple directory tree on a hypothetical FTP site.
Figure 17.3.
An FTP site's directory path even looks sort of
like a tree.
First, notice that directories on FTP sites all
begin with a slash (/). Each slash represents one level, or branch, on the FTP
site. If the file you want is in /pub/inet/web/browsers, for example, you take
the /inet branch from the /pub trunk, go to the /web limb, and
then jump to the /browsers twig (okay, maybe I'm stretching the analogy a bit).
Presumably, the file you want is in that last subdirectory.
Navigating these paths is easy once you're used to
it. If you're using a Web browser, selecting directories and using the Forward and Back
buttons enables you to navigate nicely.
If you're using an FTP client, such as WS_FTP, you
can still click directory names to move down. To move back up, however, you need to
remember to double-click the double-dot (..) at the top of each directory window. The
double-dot is another throwback to times before GUI interfaces and is standard syntax for
"go up a directory."
Names: The File Frontier
Probably the most confusing part of FTP is the
really strange names that files seem to have. If you don't know what you're doing, they
can seem almost indecipherable. You can keep in mind a couple points when dealing with
filenames, though.
First, know that most files you find on FTP sites
are compressed to save space. A compressed file has its original code
"compacted" into a smaller file. This means that you have to
"decompress" files that you download before you can use them.
Second, quite a few compression utilities are
available, which also means that you need to know many different filename extensions.
Table 17.1 gives a breakdown of the most common file extensions on FTP sites today.
Table 17.1. File extensions explained.
| Extension |
Platform |
Compressed |
Decompress with |
| .txt |
PC or Mac |
No |
N/A (text file) |
| .ps |
PC or Mac |
No |
PostScript printer file |
| .exe |
PC |
Yes/No |
Executable or
self-extracting |
| .zip |
PC |
Yes |
WinZip |
| .sit |
Mac |
Yes |
StuffIt Expander |
| .sea |
Mac |
Yes |
Self-extracting |
| .hqx |
Mac |
Yes |
Binhex StuffIt Expander
(this encoding is usually added to a compressed file). |
| .bin |
Mac |
No |
A program like Macbinary
II will convert this file. |
Of course, you will see other extensions. Extensions such as .gz, .tar,
and .Z are UNIX files that you most likely cannot use. You might be able to use
other compressions that are outdated or rare, such as .lzh or .arc; it
never hurts to try. When all is said and done, you end up with something like the window
shown in Figure 17.4.
Figure 17.4.
Both remote and local files and directories are
all visible from one FTP client.
Time Saver: Many Web browsers and FTP applications "post-process" files.
That is, if you have an decompression program installed on your machine, the client
automatically decompresses the file for you after it's downloaded. Check your client's
documentation to see if your software has this capability.
Downloading Files
I've given you all the pieces. Now you're ready to
put them together and download that first file to your hard drive. Starting out with
something easy, like a decompressed text file, is probably a good idea.
Time Saver: Most Web browsers simply display
a text file in a browser window instead of downloading it. If you want to save the file to
your hard drive, right-click the filename and then choose the option that enables you to
save the file.
To Do: Downloading Files
- 1. Point your client to mirrors.aol.com (FTP
client) or ftp://mirrors.aol.com.
2. Take the directory path /pub/music/lyrics/d/dire.straits/.
3. Choose one of the albums listed, and download it to your computer's hard drive.
4. Open a word processing program.
5. Open the file you just saved to your hard drive and view it.
Next, download something useful. You may have
already glanced at Appendix B and noticed that WinZip is listed as a great utility for
decompressing files. Well, why don't you go ahead and download the latest demo version
right now?
To Do: Downloading the Demo
- 1. Point your FTP client (or Web browser) to ftp.winzip.com.
2. Take the directory path /winzip/winzip/.
3. Choose one of two files to download at this point. If you have Windows 95, choose winzip95.exe.
If you have Windows 3.1, choose wz16vXX.exe (where XX represents the
most current version).
4. Download the appropriate file to your hard drive.
5. Choose File|Run (in Windows 3.1) or Start|Run (Windows 95) to run the file you just
downloaded.
6. Choose the WinZip Setup option, and follow the directions to set up WinZip.
Time Saver: If you are using a Mac, you might
want to go ahead and download StuffIt Expander. Simply go to http://www.aladdinsys.com/consumer/expander2.asp
and follow the instructions provided on the page.
Browser Versus Client
Probably the biggest choice you face when using FTP
is the software you'll use. You have two basic choices: a Web browser or a client designed
specifically for FTP. Each solution has its own drawbacks, but you should carefully
consider a few factors.
Usability
The first issue is that of usability. For ease of
use, a browser wins hands down. Using either Netscape or Internet Explorer, the process of
finding and downloading files is as easy as browsing the Web--everything remains
point-and-click. You can use a Web site, such as http://www.shareware.com/,
to find the files and then click your way to the file you want to download. Figure 17.5
shows such an example.
Figure 17.5.
Browsers offer you Web ease for finding and
downloading files.
I'm not saying that FTP clients are hard to
use--they really aren't. However, figuring out exactly how to use these clients definitely
takes longer. Also, your using FTP clients doesn't mean that you can't still use a browser
to find files--you can. In fact, many FTP pros regularly use the strengths of both
browsers and FTP clients to get files quickly and efficiently.
Flexibility
The second real issue to consider when choosing a
browser versus a client is flexibility. How many different tasks a browser or client can
perform is also of utmost importance. On this measure, the FTP client wins without
question.
For the most part, using a browser, you can find,
download, and upload files, and that's about it. A client, however, offers an entire world
of functionality. Many clients, such as WS_FTP for Windows and Fetch for Macintosh,
actually act as miniature file managers as well as FTP clients. You can usually change
download directories and filenames, delete files, and download multiple files all from one
piece of software, as you can see in Figure 17.6. Often, you can also view and even launch
files right from within the FTP client.
Figure 17.6.
Do you want to save some time by downloading
several files at once? Don't use a Web browser!
You will probably find yourself using both a browser
and a client to use FTP. For many everyday FTP tasks, a browser works fine. For the times
you need a more powerful tool, you may want to take advantage of what an FTP client has to
offer.
Summary
In this lesson, you learned about what FTP is and
how it works. Now you know that two different types of FTP sites exist, one of which
(anonymous FTP sites) you can access to get all types of files, documents, and software.
You also learned how FTP sites are organized so that
you know how to find, explore, and get what you want. Finally, you learned how to download
files using FTP, as well as some of the pros and cons surrounding what type of FTP
software to use.
Workshop
The following workshop helps solidify the skills
that you learned in this lesson.
Q&A
Q I know that all this great stuff available via
FTP really isn't free. Is that true?
A Sort of. Many files, particularly software, are generally offered as shareware.
Shareware is software that is distributed freely. If you find that you use shareware on a
regular basis, however, you are usually asked to send in a small fee ($10 to $25). This
way, shareware developers can continue writing useful, inexpensive software for you to
use.
Q Do I have a limit on how many files I can download?
A Not really. The only restriction you usually have is time. Using a modem connection,
downloading very large files can take up to an hour or more. How you pay for your Internet
service and how much time you have to spend online are most likely the determining factors
in how much you actually download.
Q Is a file extension really platform specific?
A Yes and no. Consider an example. Suppose that you have a very large text document
that you want to compress. If you're using a PC, you can use WinZip to compress the file
and call it text.zip. Another person can download this same file to a Macintosh,
unzip it using StuffIt Deluxe, and view it without a problem. Generally, software and
applications with compressed file extensions are platform specific.
Quiz
Take the following quiz to see how much you've
learned.
Questions
- 1. Of the following choices, which one
describes a directory path?
- (a) ftp.site.com
(b) /pub/graphics/util
(c) docviewer.zip
2. Which of these files would be fastest to download?
- (a) goodfile.tar.gz
(b) goodfile.zip
(c) goodfile.txt
3. An anonymous FTP site doesn't require any information from you in order for you to
use it.
- (a) True
(b) False
Answers
- 1. (b) /pub/graphics/util
2. (c) Files with no compression are always fastest.
3. (b) False. You must provide a user ID of anonymous and a password of your
e-mail address to log on.
Activity
Now you can really apply what you've learned and
still have some fun. In this lesson, you downloaded WinZip. Now go out and download a
compressed file. First, go to http://www.shareware.com
and search for games. Find a compressed game that looks interesting, download it,
and then decompress it. Yes, you can play some before moving on to the next lesson.
|
What is Internet
