File Transfers

There are two parts to successful file transfer: file format, and transfer method. It does not make sense to send a message to someone who cannot speak your language. Nor does it make sense to send a file if the receiver cannot use it. But most time wasted with file transfers is on the receiving end, due to incompatible file formats.

Step 1 -- File Format
    strategies for senders
    strategies for receivers
Step 2 -- Getting it (from) there
    sneakernet
    e-mail
    www
    FTP (file transfer protocol)
    outgoing anonymous FTP
    network filesharing
    kermit / zmodem
archiving and compression
recommendations for within the department

Step 1 -- File Format

There are 3 file format strategies for the file sender:
1. check beforehand
to see what software, and what version of that software, the receiver uses. Then save your file in the format they require before you send it.
2. use a "universal format"
which virtually any software can handle. Two such formats are ASCII text and Rich Text Format. ASCII text is plain old typewriter characters, just as could be typed in from your keyboard. MS Word refers to it as "text-only with linebreaks". The CSV format of MS Excel is also an ASCII text format.
    Although anything can handle ASCII, you lose font information and formatting. Rich Text Format preserves font information and some other formatting, but is not appropriate for any document with figures.
3. use a format for which the software is free
Adobe's Acrobat format (called Portable Document Format, or PDF) is a good choice for any document, even complicated ones, because the Acrobat Reader is free, and available for many different kinds of computer systems. The catch is that the software to makeAcrobat files is not free. Note: Acrobat files are muchsmaller than Word files. If the receiver does not need to edit it in Word, send as a PDF file. See the Acrobat section below.
4. guess
Obviously this is the highest risk method, but there are ways to make a smart guess. When software makers develop a new version, they make sure that their customers' older files, made in previous versions, will still work. In other words, they ensure "forward compatibility". The problem is that new file formats are often not readable by older versions of the same software, i.e. they are NOT "backward compatible". So guess an older version to make it more likely the receiver can handle the file format. For example, if you have Word97, don't assume your buddy does. Save the file as Word 6 format before you send it. That way if the receiver has Word 6 or anything later, or other software that can import Word 6 format, they will be able to read your file. It's always a bad bet to send the very latest in file format unless you are sure the receiver also has the latest software version. The only catch is that older formats do not store the latest features of the software. If you've used them, better opt for strategy 1, above.
The receiver of files, on the other hand, has 2 file format strategies:
1. have the very latest versions of a variety of software
This is one way to be able to handle anything anyone tosses your way, but it's an expensive way.
2. have the latest format conversion software
This is the more rational route. Keep using your favourite version of your favorite software. To cover all the possibilities for incoming files, have the latest version of some good format converting (file translation) software. Conversions Plus (for Windows) and MacLinkPlus (for the Mac) are good choices.

Step 2 -- Getting it (from) there

There are several choices of method of file transmission. Again, it is important to keep the capabilities of the receiver in mind.

sneakernet
Do not be too quick to discount the efficiency of time-honoured "sneakernet". This means simply writing your file(s) to a removable medium (floppy, Zip, CD, Jaz) and running down the hall to the destination machine. Remember to check the capabilities of the receiver. Do they have a Zip drive? The capacities of those four media are, respectively: 1.4MB, 100 or 250MB, 650MB, and 1 or 2 gigabytes.
e-mail -- in the message body, or as an attachment
If you have a file in plain (ASCII) text format, there is no need to fool around with attachments. Consider just including your file as part of the message body itself. Any receiver should be capable of saving the message, and then using their favourite editor to prune out the parts of the message they don't need. Let's say that the ASCII file you want to send is called data.txt. To include this file within your message body, in:
Eudora
At the point in the message where you would like your ASCII file read in, go to Message --> Attach Documenthighlight the file in the panel, and then press the Insertbutton. Done.
Pine
At the point in the message where you would like your ASCII file read in, type a control-rcharacter and type in the path (name) of the ASCII file when prompted.
mail
For people like Alistair who still use "mail", just type ~r data.txtat the start of a line, followed by a return.
Netscape
Netscape mail can't easily read a file into the message body. So you have to do it by opening data.txt in an editor, selecting the whole file, copying it, and then going to your mail message window and pasting it in.

Anything that is NOT plain ASCII text, such as the usual Word and Excel formats, must travel by e-mail as an attachment. There are a few "standard" attachment protocols, and a few ways of encoding the information within the attachment. The most common attachment is MIME (Multipurpose Internet Media Extensions). Set your mail software to use it. On Macintosh Eudora choose AppleDoubleas the encoding method under Settings-->Attachments.

Receiving attachments is a different matter. Sometimes they are not using the attachment or encoding protocols your mail program expects. Common examples are uuencoded and binhexed attachments. Those protocols have been around since before MIME. Uuencoded files start with "begin 644 filename", where the number may differ, and end with an "end". Binhexed files plainly state that "This file must be converted with BinHex". Either can be decoded using Stuffit Expander on Windows or on the Mac. If you use "pine" as your mail reader, save the message to a file. Then run "uudecode file", and a new file by the name that was on the "begin 644" line will appear in your directory. If the file contains binhexed info, strip out the stuff before the "(This file must be converted with BinHex)" line (using an editor like "pico" or "vi") and then type "mcvert file". Alternative: tell the sender to please use MIME attachments.

Note: There are very few formats that are allowed to be sent or received due to the proliferation of virus and trojan programs that hide their true file types with just a change to the extension or being placed inside a .zip file. Windows in particular will treat a program that has been renamed to something inocuous like a .txt file and will execute the file when the email is opened or previewed in Outlook. Other Windows email programs will not do this, so, unless absolutely necessary, don't use Outlook for email.

The following file types/extensions are not allowed:
exe, vbs, pif, scr, bat, cmd, com, cpl, ade, adp, app, bas, bat, chm, cmd, com, cpl, crt, fxp, hlp, hta, inf, ins, isp, js, jse, lnk, mda, mdb, mde, mdw, mdt, mdz, msc, msi, msp, mst, ops, pcd, pif, prg, reg, scr, sct, shb, shs, vb, vbe, vbs, wsc, wsf, wsh, mim, b64, bhx, hqx, xxe, uu, uue, exe-ms

WWW
We do have a method of transferring files, but not through email. We provide a file transfer service via a web browser. You can create an account at this web page. Press "Login" and then "Register" on the next page but don't use your regular password. You can then email this URL and account info to the person trying to send you the file and they can then transfer the file. They can then email you back, you can retrieve the file and then delete it and change the password. If you wish to delete the account, contact the ZCU administrators.

Each account created by this program has its own private transfer area. Other users cannot see your files and the files are stored in an encrypted format on the server.

For personal use, there are two services that you can use. www.panda.com allows up to a gigbyte of data while www.yousendit.com allows up to 100 MB.

FTP
File Transfer Protocol requires that you have access to the remote machine, either to getstuff from it or to putstuff there. Often other machines will allow anonymous access for people getting files. FTP is fast and efficient. It can be used raw, with a special program, or from within a web browser. Two nice FTP programs are Fetch (Macintosh) and WS-FTP (Windows).
raw - from UNIX command line or Windows Runwindow, do this:
ftp ftp.theirsite.edu
login: anonymous
password: myname@zoology.ubc.ca    (it's polite to give your e-mail address)
cd pub    (use cd and ls to change directories and look around)
ls -CF
binary    (must say this unless the file you want is plain text)
help    (if you need it)
get filename
quit
Fetch (Mac)
Open a connection to the remote machine and drag the file you want out of the Fetch window (to get it), or drag one into the Fetch window to put it on the remote machine. If you need help, check under the question mark at the top right of the screen.
WS-FTP (Wintel)
This uses a split window with a local and a remote pane. Select the file you want, and send it in the direction you want.
using a browser
Modern web browsers will automatically use FTP when given URL's (Universal Resource Locators) of the form starting with "ftp://". When not being anonymous there is a way to incorporate the account-name (ID) information in the URL. For example, if your ID is "yorque" on our machine you would point your browser at "ftp://yorque@ftp.zoology.ubc.ca", at which point your browser will prompt you for your password, and then show you your home directory. Click on a file to download it, or use File --> Upload File(Netscape) to transfer a file the other way.

outgoing anonymous FTP
Let's say that a colleague needs one of your files. It's quite big, they would like to grab it by means of FTP, and said colleague does NOT have an account on our Zoology systems. Do not give out your password, do this instead (only members can):
  1. At your UNIX prompt:   ls /usr/ftp/pub
  2. Is your account-name there? If not:   mkdir /usr/ftp/pub/yourID
  3. Once that directory exists, just copy anything you'd like to make available for anonymous FTP transfer into that directory:   cp yourfile /usr/ftp/pub/yourID
  4. Tell your colleague to point their FTP tool at ftp.zoology.ubc.ca and then change directory into pub/yourID, or point their browser at ftp://ftp.zoology.ubc.ca/pub/yourID
Please be sure to erase your files from the ftp directory as soon as you no longer need them:   rm /usr/ftp/pub/yourID/yourfile.

network filesharing
Filesharing is another means of transferring files if both source and destination computer are on the Internet. This can be done via a server machine, or peer-to-peer. The latter, turning your computer into a file- web- or FTP-server involves a certain level of security risk by opening your machine to others. We won't explain that here (yet). (Macintosh file sharing.) A safer route is to transfer the file(s) from the source machine to the Zoology server, and then transfer it(them) from the Zoology server to the destination machine.
Macintosh
  1. Log onto the server by using Chooser --> AppleShare --> zone zoology.ubc.ca --> file server Zoology and entering your e-mail name and password. This creates an icon on the Desktop with your name on it, which can be used just like any other drive. (in pictures) Copy your file(s) there.
  2. Go to the destination machine, log onto the server as above, and copy the file(s) from the Desktop icon to the local machine.
Wintel
  1. When you logged into your (fully Zoology networked) Windows machine, an H: drive was created that contains all of your files that are stored on the Zoology server. You can copy files there and then,
  2. log onto another Windows machine and copy the files off.

kermit / zmodem
Well, supposing you are on a phone line, over a plain character-based link that does not support the SLIP or PPP protocol that is required by FTP and browsers. Then what do you do? Use good olde kermit or zmodem transfer protocols. These methods require that there be a program running at either end of the line: at one end packaging the information and writing the packing slip, and at the other end unpackaging the info and reading the packing slip to be sure that everything arrived intact. With proper setting up, kermit can be as fast as any other protocol, it usually defaults to the most robust (and slow) settings. So if it's an easy choice, try zmodem first. Hyperterminal (Windows) under Programs --> Accessories --> Hyperterminalsupports both transfer protocols. Kermit is available for free for virtually any platform.
The general procedure is always the same:
  1. Once connected to the remote machine, start up either the receiving or the sending part of the protocol, as required
  2. and then, back on the local machine start up the opposite end of the communication (sending or receiving, respectively).

archiving and compression
It is often easier to archive many files and then transfer them as one lump, than to transfer many separate files. And it often saves time to compress a file and then transfer and uncompress it, rather than transfering it uncompressed, and big. Note that e-mail attachments are always encoded as ASCII, so even a compressed file becomes "decompressed" and much larger as an attachment.

recommendations for the department
  • e-mail software: Thunderbird -- good, free, and available for both Mac and Windows
  • general purpose: Adobe Acrobat Reader -- for e-mail attachments and web docs
  • best format for read-only document: Adobe Acrobat (PDF)
  • FTP software: Fetch or WS-FTP
  • archiving software:
  • compression software:
  • decompression software: Stuffit Expander (both Mac and Windows) -- unwraps just about any archive/compression/attachment format
  • translation software: MacLinkPlus (Mac) or ConversionsPlus (Windows)
  • super-huge file: compress, use FTP
  • plain text: e-mail within message body
  • binary (non-text): e-mail attachment or FTP
  • no e-mail connection: use FTP (if on Internet via ethernet, SLIP or PPP) or use zmodem (if on plain phone connection)

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