9.1 The File's in the Mail
Big Dummy's Guide to the Internet

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     E-mail by itself is a powerful tool, and by now you may be
sending e-mail messages all over the place.  You might even be on a
mailing list or two. But there is a lot more to e-mail than just
sending messages.  If your host system does not have access to ftp,
or it doesn't have access to every ftp site on the Net, you can have
programs and files sent right to your mailbox.  And using some simple
techniques, you can use e-mail to send data files such as spreadsheets,
or even whole programs, to friends and colleagues around the world.
     A key to both is a set of programs known as encoders and
decoders.  For all its basic power, Net e-mail has a big problem: it
can't handle graphics characters or the control codes found in even
the simplest of computer programs. Encoders however, can translate
these into forms usable in e-mail, while decoders turn them back into
a form that you can actually use. If you are using a Unix-based host
system, chances are it already has an encoder and decoder online that
you can use. These programs will also let you use programs posted in
several Usenet newsgroups, such as comp.binaries.ibm.pc.
    If both you and the person with whom you want to exchange files use
Unix host systems, you're in luck because virtually all Unix
host systems have encoder/decoder programs online.  For now, let's
assume that's the case. First, upload the file you want to send to your
friend to your host site (ask your system administrator how to upload a
file to your name or "home" directory if you don't already know how). 
Then type
 
                uuencode file file > file.uu
 
and hit enter. "File" is the name of the file you want to prepare for
mailing, and yes, you have to type the name twice!  The > is a Unix
command that tells the system to call the "encoded" file "file.uu"
(you could actually call it anything you want).
     Now to get it into a mail message.  The quick and dirty way is to
type
 
                mail friend
 
where "friend" is your friend's address.  At the subject line, tell
her the name of the enclosed file.  When you get the blank line, type
 
                ~r file.uu
 
or whatever you called the file, and hit enter. (on some systems, the ~
may not work; if so, ask your system administrator what to use).  This
inserts the file into your mail message.  Hit control-D, and your file
is on its way!
     On the other end, when your friend goes into her mailbox,  she
should transfer it to her home directory.  Then she should type
 
                uudecode file.name
 
and hit enter.  This creates a new file in her name directory with
whatever name you originally gave it.  She can then download it to her
own computer.  Before she can actually use it, though, she'll have to
open it up with a text processor and delete the mail header that has
been "stamped" on it.  If you use a mailer program that automatically
appends a "signature," tell her about that so she can delete that as
well.