The Online World Part 27

This is an interesting feature when in that far away place without a printer. Send the draft contract or other texts to your hotel's fax machine or to your client's office to get a printout on paper.

Privacy ------- The level of online privacy differs by network, service, and application. Whatever these services may claim, always expect that someone, somewhere, is able to watch, even record.

All mailbox services have at least one person authorized to access your personal mail box in case of an emergency. Most of the time they not have a right to read it without your permission, but they can.

In some countries, mailbox services may let outsiders (like the police) routinely read your private email to check for 'illegal'

contents. In this respect, email is not safer than ordinary mail.

The good news is that most 'inspectors' and 'sysops' are good, honest people. On the other hand, it is useful to know your situation.

It is not safe to send sensitive information (like credit card details) by private electronic mail. True, the probability that an outsider should get hold of and take advantage of such information is small, but it definitely is not 100 percent safe.

Encrypt your email to protect sensitive information.

Always a.s.sume that someone is recording all that is being said in online conferences, chats, and other interactive social gatherings.

In chats, anyone using a personal computer as a terminal can log the conversation, or use screen dump just to capture 'interesting parts'.

Many PC users can scroll back the screen. They can wait and decide whether to save the conversation in a file until after the conversation has taken place. With these capabilities widely available, users of chats and talk should always a.s.sume that their conversations are being recorded.

Do not say indiscreet things in small, informal discussions. It may be recorded and reposted under embarra.s.sing circ.u.mstances.

The program PGP has become the defacto international Internet standard for public key encryption.

For more on privacy, check out [email protected] The files RFC 1113 through 1115 are about 'Privacy enhancements for Internet electronic mail' (see appendix 1 for how to get them).

Usenet has alt.privacy (Privacy issues in cybers.p.a.ce), and comp.society.privacy (Effects of technology on privacy).

File transfers through the Internet ----------------------------------- The Internet is a term used of a network interconnecting hundreds of thousands of computer centers around the world. These centers use different types of hardware and software, and different methods of file transfer.

What method to use for file transfers depends on the source host and the type of mailbox computer that you are using. The transfer usually takes place in two steps:

1. Transferring files from a remote data center to your local mailbox host.

2. Transfer from your local mailbox host to your personal computer.

Transfer to your local mailbox host ----------------------------------- We will explain the most commonly used method for those who only have access to file transfer by email. This method can be used by everybody.

Transferring plain text files is easy. Files with imbedded word processor control codes will often have to be treated as binary files. More about this later.

To transfer a text to another user, just send it as an ordinary electronic message.

Getting text files from a library on a remote computer is a special case. Often, they can be had by sending a retrieval command (like GET) by email to the remote center. After a while, the file will be sent to your mailbox by email. You can read it like you read other mail.

Example: The file BINSTART can be retrieved from the KIDART directory on a computer center in North Dakota, U.S.A. It explains how to retrieve binary art files from the KIDLINK project's file libraries.

To get the file, send a message to the center's mail forwarding 'agent' at [email protected] Use the following command syntax in your text:

GET

To get the BINSTART file, write the following command in the TEXT of your message:

GET KIDART BINSTART

Note that the command has to be put in the body of the mail and not in the subject field. The file will arrive in your mailbox after a while.

Also, note that lists of available files are usually available by using an "INDEX " command. To get a list of files in the KIDART directory, add the command "INDEX KIDART" in your message above.

Non-LISTSERV libraries may use other retrieval commands. Often, you can get information of what commands to use by sending the word HELP to a mailing service (in the Subject area or in the body of the text).

Transferring binary files ------------------------- Users with a direct connection to the Internet usually have access to the FTP command (File Transfer Protocol). If they do, they often prefer FTP for transfers of binary files like computer programs, pictures, sound, and compressed text files.

The bad news is that the FTP command is not available to all users of Internet mail. These will have to use "FTP by mail," or other tricks to transfer such files. More about this in a moment.

The FTP command gives access to a special file transfer service.

It works in the following way:

1. Logon to your local email host and enter 'FTP remote- center-code'. Example: 'ftp 134.129.111.1'.

This command will connect you to the center in North Dakota mentioned above. Here, you will be prompted for user name and pa.s.sword. Enter 'anonymous' as user name, and use your real name or email address as pa.s.sword.

This way of logging on to retrieve files is called "transfers by anonymous ftp." You can use this method on many hosts on the Internet.

2. When connected to the remote center, you can request transfer of the desired file to your mailbox. Before doing that, you may have to navigate to a given file catalog (cd directory), and tell the host that the transfer is to be binary (bin). Finally, initiate the transfer by entering a "GET file name" command.

3. The file will be transferred to your local mailbox computer at high speed. When the transfer is done, you logoff from the remote center to "get back" to your mailbox computer's prompt line.

Now, you can transfer the file to your personal computer using communications protocols like Kermit, XMODEM, ZMODEM or whatever else is available.

Binary files transferred as text codes -------------------------------------- If you do not have access to FTP, you must use ordinary email for your binary transfers.

Usually, email through the Internet can only contain legal character codes (ASCII characters between number 32 - 126). Most systems cannot transfer graphics or program files directly, since these files normally contain binary codes (which are outside this ASCII character range).

The solution is to convert binary files to text codes using a utility program called UUENCODE. The encoded file can be sent by ordinary email, as in this example:

From [email protected] Fri Aug 16 16:32:37 1991 Date: Fri, 16 Aug 1991 09:31:34 CDT To: [email protected] Subject: Part 1/1 SIMTEL20.INF PD:

The file PD:SIMTEL20.INF has been uuencoded before being sent. After combining the 1 parts with the mail headers removed, you must run the file through a decode program.

------------ Part 1 of 1 ------------ begin 600 SIMTEL20.INF M6T9I;&4Z(%-)351%3#(P+DE.1B'@("'@("'@("'@("'@("'@("!,87-T(')E M=FES960Z($IU;F4@,[email protected](#$Y.3%=#0H-"B'@(%M.;W1E.B!$=64@[email protected]&ES M:6P-"AH:&AH:&AH:&AH:&AH:&AH:&AH:&AH:&AH:&AH:&AH:&AH:&AH:&AH: M&AH:&AH:&AH:&AH:&AH:&AH:&AH:&AH:&AH:&AH:&AH:&AH:&AH:&AH:&AH: 6&AH:&AH:&AH:&AH:&AH:&AH:&AH:&@(Z '

end -------- End of part 1 of 1 ---------

When you receive a message with uuencoded text, download it to your personal computer's hard disk. Use an editor to cut out the codes and paste them to an empty work file. Using the example above, the first line in your work file should contain:

begin 600 SIMTEL20.INF

and the last line should contain end

Now, use a utility program called UUDECODE to convert the file back to its binary form (or whatever).

More information about uuencoding and uudecoding is given in the BINSTART file mentioned above (for MS-DOS computers). It has a detailed explanation, BASIC source code for making the program UUDECODE.COM, and a DEBUG script for those preferring that.

Versions of UUDECODE are also available for other types of computers.

Transfer of pictures -------------------- Denis Pchelkin in Protvino (Russia) is 11 years old, has two cats and one dog, and has contributed beautiful computer graphics art to the KIDLINK project (1992).

The file ART019 in the KIDART catalog of the North Dakota center contains one of his creations. It is a UUENCODEd picture in GIF graphics format.

You can retrieve Denis' creation by sending a GET command to [email protected] . Put the following command in the TEXT of your message:

GET KIDART ART019

The LISTSERVer will return a message filled with strange uu-codes.

We a.s.sume that you have already retrieved the BINSTART file, and that you have a version of the conversion program. Your next step is uudecoding: Read the message into an editor or a viewing program. Cut and paste the codes to a work file. Keep the original as backup. Use the UUDECODE.COM program to convert ART019 into a GIF formatted file.

Now, view the picture with your favorite graphics program. (Or use shareware GIF-viewers like PICEM, VUIMG, and VPIC for MS-DOS computers. These programs are available from CompuServe's IBM forums and other services.) Sending binary files in uuencoded form has weaknesses. One is the lack of automatic error correction when sending/receiving e- mail. Noise on the line can easily distort the picture.

File size is another problem. UUENCODEing typically increases file sizes by almost one third. Some mailbox systems restrict the length of individual messages that you can receive, and the file may just be too big.

If the uuencoded file gets too big, some services can (or will by default) split it up in parts and then sent separately.

Tons of uuencoded public domain and shareware programs are available for retrieval by ordinary email.

FTP by email ------------- While some services accept commands like GET KIDART ART019 by email, this is not so with the many so-called FTP libraries. Many of them can only be accessed by FTP.

Services exist that will do FTP transfers by email for those not having access to the FTP command. The most popular is at DEC Corporate Research in the U.S.

For more information, write a message to one of the following addresses:

[email protected] [email protected]

In the TEXT of your message, put the word "HELP".

FTPMAIL lets you uuencode binary files for transfers. It can split large files up into several messages, thus helping you around local restrictions on the size of each incoming mail message.