TRANSFERRING FILES TO/FROM PEGASUS
The mail server provides you with the capability
to transfer files between it and your own computer or other computers
on or off campus. This is so you can upload and download files,
mail notebooks, or message text to e-mail to other users.
Normally, when transferring a file to the mail server
If, however, the recipient of the message has a mail
reader like PINE that supports MIME attachments, you can transfer
the file to the mail server in binary mode and "attach"it to a text message. Using MIME, PINE will encode the binary
file so that it can be transferred via e-mail.
The method for transferring files to or from the
mail server depends upon how you access the mail server. If you
are accessing the mail server from a computer connected to the
Internet, you can use FTP file transfer. If you are dialing in
to the mail server via a modem or a ROLM Dataphone, you can use
Kermit or ZMODEM file transfer, whichever one your emulation package
supports.
When you are downloading files (either via FTP or
a phone modem), there are two different types you may encounter:
plain text (or ASCII) files and binary files. Plain text files
are human readable files; as soon as you download them, you can
view them on the screen. Binary files are typically executable
programs, sound or picture files, or compressed files. If you
attempt to read them on the screen, you will see nothing but garbage
(and you could lock up your computer).
The difficulty lies in telling the two file types
apart. The best clue is to look at the file type or extension.
Most file names you see will follow the DOS naming convention
of an eight character file name, followed by a period, and followed
by a three character extension. However, you may see file names,
in particular UNIX files, that can be longer and have multiple
parts to them. Here are some common extensions you may see:
| Text (ASCII) files: |
asc, doc, htm, html, read.me, txt |
| Binary files: |
compressed files (arc, gz, tar, zip, Z)
movies(avi, mov, mpg, mpeg, qt)
picture(bmp, gif, jpg, tif)
sound(aiff, au, mid, midi, wav)
programs, libraries (com, dll, exe)
|
The above list is not meant to be exhaustive. As
new software is made available, you may see other types of file
extensions. If you are not sure what type of file you are dealing
with, try downloading it as a binary file first. Binary transfer
mode will also successfully transfer text files in most cases.
If a file turns out to be a text file and binary transfer mode
made it look funny, you can switch to text mode and download the
file again.
TRANSFERRING FILES VIA FTP
General Information About Transferring Files
File transfer on the Internet is accomplished with
a method know as the File Transfer Protocol (FTP). With this method,
you log on to a remote system and then use a series of commands
(namely cd, get, and put) to transfer files.
Normally you need to have an account on the remote system, however
many sites on the Internet support what is known as 'Anonymous
FTP'. What this means is that you can FTP to a remote system without
need for an account on that system. Instead when prompted, you
provide a username of anonymous
and supply your Pegasus electronic mailing address for the password.
The sites that support Anonymous FTP often have public directories
of programs or documents you can download.
Once you connect to a particular machine, you need
to change to the directory where you wish to upload to/download
from using the cd
(change directory) command. It works just like the
UNIX or DOS version. For example,
ftp> cd /pub/systems/msdos
will place you into a directory where files for personal
computers running DOS are stored.
To get a listing of the files in the current directory,
use the dir
or ls
command. Unfortunately, it is difficult to give an example as
the output will be different depending on what kind of machine
you have connected to. Some of the more common systems you will
encounter are UNIX systems, IBM mainframes, VAX/VMS systems, or
DOS or Windows/NT systems. However, all systems should give you
three basic pieces of information: the filename, the size (usually
in bytes), and the date that the file was created or updated.
When you are ready to download a file, you will need
to set the file transfer mode according to what type of file you
are dealing with. See general discussion of file types.
The default file transfer format is ASCII. To change to
binary file transfer, type the following at the ftp prompt:
ftp> binary
To change back to ASCII file transfer, type the following
at the ftp prompt:
ftp> ascii
The two commands that you will be using to transfer
files are get and put. The get command "gets"a file from another system and brings it to the system you issued
the FTP command from. The put command "puts" a file
from the system you issued the FTP command from to another system.
It is important to understand these two commands as which one
you use depends on what system you issued the FTP command from.
The syntax of the get command is:
ftp> get filename1 filename2
where filename1 is the name of the
file on the system you are getting the file from and filename2
is what you want the file to be named when it is transferred to
you. If you wish to keep the same filename as filename1
then you do not need to specify filename2.
The syntax of the put command is:
ftp> put filename1 filename2
where filename1 is the name of the
file that you are transferring to another system and filename2
is what you want the file to be named when it is transferred from
you to the other system. If you wish to keep the same filename
as filename1 then you do not need to specify filename2.
Note that you must have the ability to write to the directory
that you wish to put a file to. For anonymous FTP sites, you typically
have read-only access.
When you are done transferring files, you need to
close the connection and exit the FTP program. To do this, issue
the following commands at the FTP prompt:
ftp> close
ftp> quit
If you have transferred files to Pegasus or some
other UNIX based system, be sure to check the file permissions
of the transferred files. Sometimes the FTP software may set the
permissions such that other users can read the files. For more
information on file permissions, see UNIX File Security (File Permissions)
One final thing to note about filenames is that they
are case sensitive, which means that upper and lower
case letters do make a difference. Keep this in mind when you
are specifying filenames for the get and put commands.
In the following three subsections, examples are
given for transferring files to and from the Pegasus mail server.
These examples can be used a guide for dealing with systems other
than Pegasus. Please note, however, due to differences in software
and operating systems on other systems, the responses you see
may be different.
If you are using a SLIP/PPP connection, you can transfer
files to and from your computer by using an FTP client (one comes
with the Internet Starter Kit and with Windows 95 and NT). Although
the interface is often mouse or menu driven, the same concepts
of binary verses text transfer and getting verses putting a file
still apply. In this case, you will be using get to transfer
files to your computer and put to transfer files from your
computer to another system. See the documentation that came with
your package for more information on using an FTP client (if one
was provided).
If you are issuing the FTP command at the pegasus%
prompt:
1. Issue the FTP command:
pegasus% ftp address
where address
is the Internet address of the other system
to transfer files to/from. When asked, provide the username and
password for a valid account on the other system. If you are connecting
to a public FTP system, the userid will be anonymous
and the password will be your electronic mailing address.
2. If you are transferring files from the mail server
to another system, then type the following command:
ftp> put filename1 filename2
where filename1 is the name of the
file on the mail server and filename2 is what you
want the file to be named when it is transferred to the other
system.
3. If you are transferring files from another system
to the mail server, then type the following command:
ftp> get filename1 filename2
where filename1 is the name of the
file on the other system and filename2 is what you
want the file to be named when it is transferred to Pegasus.
Example:
There is a neat program named neatprog.zip
located in the directory /pub/systems/msdos
at the Internet site wuarchive.wustl.edu.
To download this program, do the following:
1. At the pegasus prompt, type the following command:
pegasus% ftp wuarchive.wustl.edu
You will be asked for a username and a password.
Respond with a username of anonymous
and provide your electronic mailing address for the password.
2. Switch to the directory containing the program:
ftp> cd /pub/systems/msdos
3. Since this program has a filetype of .zip,
it is a compressed file and thus needs to be downloaded as binary
data. Turn on binary transfer mode as follows:
ftp> binary
4. Now you can download the program:
ftp> get neatprog.zip
5. You now wish to upload one of your own programs
so that others on the Internet can use it. Your program is named
myprog.exe.
Since it is executable code, it must also be transferred using
binary mode. You are already in binary mode, so you can just upload
the program:
ftp> put myprog.exe
If you are issuing the FTP command at another system's prompt:
1. Issue the FTP command:
ftp pegasus.cc.ucf.edu
When asked, provide your Pegasus userid and password.
2. If you are transferring files from the mail server
to another system, then type the following command:
ftp> get filename1 filename2
where filename1 is the name of the
file on the mail server and filename2 is what you
want the file to be named when it is transferred to the other
system.
3. If you are transferring files from another system
to the mail server, then type the following command:
ftp> put filename1 filename2
where filename1 is the name of the
file on the other system and filename2 is what you
want the file to be named when it is transferred to the mail server.
Example:
You are visiting a colleague at another university
when you realize that you forgot to print out and bring with you
a document stored on your Pegasus account. Your friend has obtained
for you a guest account on his school's system so that you can
transfer the document (named report.txt)
to you and print it out on a local printer. To transfer your document,
do the following:
1. Issue the following command at the prompt:
ftp pegasus.cc.ucf.edu
You will be asked for a username and a password.
Provide your Pegasus username and password.
2. Since the file you are transferring is a text
document, you can use ascii transfer mode, which is the default
mode FTP starts with. Transfer the file as follows:
ftp> get report.txt
3. Your friend gave you an interesting document (named
info.txt)
that you would like to transfer back to your Pegasus account.
Transfer the file as follows:
ftp> put info.txt
If you are using your PC LAN account on Computer Services LAN:
1. After you log on to your PC LAN account and type
pegasus, you will see a menu. Select the option for transferring
files. If you are already logged on to the mail server, then log
off and the menu should reappear.
2. If you are transferring files from the mail server
to your diskette, then type the following command:
ftp> get filename1 a:filename2
where filename1 is the name of the
file on the mail server and filename2 is what you
want the file to be named when it is transferred to your diskette
(don't forget the a:).
Be mindful of DOS's restrictions on filenames: a prefix with a
maximum of 8 characters, followed by a period, followed by a suffix
(extension) with a maximum of 3 characters. If filename1
does not meet these requirements then be sure to specify a legal
DOS filename for filename2.
3. If you are transferring files from your diskette
to the mail server, then type the following command:
ftp> put a:filename1
filename2
where filename1 is the name of the
file on your diskette (don't forget the a:)
and filename2 is what you want the file to be named
when it is transferred to the mail server.
Example:
Uh-oh...you log on to your Pegasus account and the
system complains that your disk quota has been exceeded. You decide
to reduce your disk usage by downloading some mail folders to
a diskette. In particular, it looks like your saved-messages
folder is getting very large. To download the mail folder, do
the following:
1. Log on to your PC LAN account and type pegasus
in your LAN temparea or other directory you have write access
to. Then select the option for transferring files from the menu.
2. When asked for your username and password, provide
your Pegasus username and password.
3. Since the filename saved-messages
violates DOS's rules for filenames, you will have to give it another
name as it is downloaded:
ftp> get mail/saved-messages
a:savemsg.fld
4. Now that you have transferred the mail folder
to a diskette, you can log on to your Pegasus account normally,
switch to the mail subdirectory and delete the folder:
pegasus% cd mail
pegasus% rm saved-messages
pegasus% cd
TRANSFERRING FILES VIA MODEM
The protocols available for sending a file to or
from the mail server via modem are Kermit and ZMODEM. Kermit is
a communications protocol developed by Columbia University and
is available from Columbia at no charge. ZMODEM is available from
many public bulletin boards and FTP sites. If you do not have
a copy of Kermit or a software communications package that supports
the Kermit protocol, you can get a basic version of Procomm for
DOS, which supports Kermit. To do so, have a blank diskette (3
½" or 5 ¼") ready and log on to your PC LAN
account and type dialup. Documentation is included on the
disk.
In the following subsections, you will be given two
forms of each command: one for text files, and one for binary
files. A general discussion of file types. Please
note that filenames are case sensitive, which means
that upper and lower case letters do make a difference. Keep this
in mind when you are specifying filenames for the file transfer
commands below.
To transfer a file from the mail server using Kermit:
Quit PINE (<Q>)
if you started it. At the pegasus%
prompt, issue the following command:
pegasus% kermit -s filename
for ascii (text) files
pegasus% kermit -i -s filename
for binary (program) files
where filename
is the name of the file or mail folder you wish to transfer.
After issuing the Kermit command on the mail server,
instruct your communications program to receive the file with
the Kermit protocol. Mail folders created with the Save
command (<S>)
are kept in the "mail"sub directory and must be specified as mail/filename.
For example, to transfer your default saved mail folder, which
is named "saved-messages,"the command is
pegasus%
kermit -s mail/saved-messages
To transfer a file to the mail server using Kermit:
Quit PINE (<Q>)
if you started it. At the pegasus%
prompt, issue the following command:
pegasus% kermit -r
for ascii (text) files
pegasus% kermit -r -i
for binary (program) files
After issuing the Kermit command on the mail server,
instruct your communications program to send the file with
the Kermit protocol. Consult your communications program documentation
for further information regarding Kermit file transfers.
To transfer a file from the mail server using ZMODEM:
Quit PINE (<Q>)
if you started it. At the pegasus%
prompt, issue one the following commands:
pegasus% sz -a filename
for ascii (text) files
pegasus% sz -b filename
for binary (program) files
where filename
is the name of the file or mail folder you wish to transfer. After
issuing the transfer command on the mail server, instruct your
communications program to receive the file with the ZMODEM protocol.
Mail folders created with the Save
command (<S>)
are kept in the "mail"sub directory and must be specified as mail/filename.
For example, to transfer your default saved mail folder, which
is named saved-messages,
the command is
pegasus%
sz -a mail/saved-messages
To transfer a file to the mail server using ZMODEM:
Quit PINE (<Q>)
if you started it. At the pegasus%
prompt, issue one the following commands:
pegasus% rz -ae for
ascii (text) files
pegasus% rz -be for
binary (program) files
After issuing the transfer command on the mail server,
instruct your communications program to send your file with the
ZMODEM protocol.