enthusiasts, and provides information on wineries in Washington state. 9.11 LYNX COMMANDS Down arrow Go to next highlighted link Up arrow Go to previously highlighted link Right arrow Same as hitting enter on a highlighted link Left arrow Move back to previous document + Scroll down to next page - Scroll back to previous page ? or h Help a Add current page to bookmark file c Send a comment to the creator of the current document d Download the document on your screen g Go to specific resource (you'll have to type in its address, or URL) m Return to main, or first, screen o Set personal options (for example, your e-mail address) p Print, save or download a document v View your bookmark file z Cancel document or image transfer backspace View your past links in the current session delete Same as backspace = Get address information for current file or link / Scan the current document for a keyword 9.12 WHEN THINGS GO WRONG * You try to connect to a site, but get an error message along the lines of "ERROR 404 Not found - file doesn't exist or is read protected [even tried multi]" Re-check the spelling of the site address you entered. WWW addresses are case-sensitive, so that might be a problem, as well. Hit your left arrow key, then g, then try entering the address again. It is also possible you did nothing wrong, but that the person in charge of maintaining the site either forgot to set the document so that outsiders could read it or deleted it without telling anybody. * You know the URL is correct, but when you type it in and hit enter, you get a "not available" message. Sometimes, links just don't seem to work the first time. Hit g and enter again and it may work the second time. * You try to use g to get to a new site and nothing happens. Lynx does not seem to let you go to sites from error-message pages and some other pages. If that happens, hit your left arrow, then try again. * You try to go to the next (or previous) hyperlink on a page, but are instead transported to an entirely different document. Chances are you tried to get to the next hyperlink by using your left or right arrow keys, rather than your down or up keys (remember, this'll take some getting used to). If you think you hit your right arrow key, now hit your left arrow key and you'll be brought back to the original page. If you hit your left arrow key, go to your history page (by hitting your delete key) and then chose the appropriate page to which you want to return. 9.13 FYI If you want to see what's new each week on the Web, check out the What's New service at http://gnn.com/gnn.wn.whats-new.html. You'll also find postings of new services in the alt.internet.services and comp.infosystems.www.announce Usenet newsgroups. Once a month, Thomas Boutell posts a WWW FAQ (answers to "Frequently Asked Questions") in the news.answers and comp.infosystems.www newsgroups in Usenet. You can also retrieve a copy via anonymous ftp (or ncftp) at rtfm.mit.edu. Look in the pub/usenet/news.answers/www directory for a file called faq. The National Center for Supercomputing Applications maintains a good introductory guide to HTML and related programs at http://union.ncsa.uiuc.edu/HyperNews/get/www/html.html You can get more information about TIA software via anonymous ftp at marketplace.com. In the /tia directory, you'll find copies of the software for several Unix varieties. In the /tia/docs directory, you'll find documentation, answers to frequently asked questions, etc. Frank Hecker's "Personal Internet Access Using SLIP or PPP; How You Use It, How It Works," gives a good overview of how the two protocols work. It's available via FTP at ftp.digex.net as /pub/access/hecker/internet/slip-ppp.txt or via the World-Wide Web at http://www.charm.net/ppp.html. At that latter URL, you'll find numerous other documents and programs related to SLIP/PPP access, including information and files related to Macintosh SLIP service. Henry Kriz has written a three-part series on connecting Windows computers to the Internet via TCP/IP, SLIP, etc. that goes into more technical detail than what you've just read. It's available via anonymous FTP at nebula.lib.vt.edu in the /pub/windows/winsock directory. Look for a file with a name like wtcpip05.asc, where the two digits in the first part of the name indicate the current version number. Chapter 10: ADVANCED E-MAIL 10.1 THE FILE'S IN THE MAIL 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 usefulness, basic 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, type 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. The past couple of years have seen the development of the Multi-purpose Internet Mail Extensions (MIME), which make e-mailing these files even easier. If you use an e-mail program such as cc:Mail or Microsoft Mail at work, or if you dial into bulletin-board systems, then you're used to the idea of file attachments -- you write a message, and then tell the computer you want to attach a file. MIME is essentially the Internet equivalent. The one caveat is that your recipient also has to have a MIME-enabled mail program; otherwise you could run into problems (and in that case, you'll have to fall back on uuencode). Probably the best way to use MIME on a Unix public-access site is with Pine -- it makes it very easy. Let's say you've just uploaded a graphics file that you want to mail to a friend. Call up Pine and start a message to your friend. With the cursor still in the header area (i.e., the area where you put in his e-mail address), hit control-J. You'll be asked for the name of the file you want to attach. Type in its name (or path if you put it somewhere besides your home directory) and that's it! You can now compose a message to your friend and then send it off as you would normally (only now it will come with an attached file). Assuming your recipient also uses Pine, when he gets your message, one of his options will be to hit control-V. If he hits that, he'll be asked if he wants to view or save the attached file. Assuming it's a binary file, he should hit his s key and then type in the name of the file under which to save the attachment. When he exits Pine, he can then download the file -- without the muss of first uudecoding it. A number of companies now sell software that lets users of proprietary e- mail systems send and receive MIME attachments. So if you plan on exchaning binary files with somebody on one of these systems (our friend, the cc:Mail user, for example) -- ask if her system can accept MIME attachments. It will make life a lot easier for both of you. 10.2 RECEIVING FILES If somebody sends you a uuencoded file through the mail, you'll have to go through a couple of steps to get it into a form you can actually use. If you are using the simple mail program, go into mail and type w # file.name where # is the number of the message you want to transfer and file.name is what you want to call the resulting file. In pine, call up the message and hit your O key and then E. You'll then be asked for a file name. In elm, call up the message and hit your S key. You'll get something that looks like this: =file.request Type a new file name and hit enter (if you hit enter without typing a file name, the message will be saved to another mail folder, not your home directory). In all three cases, exit the mail program to return to your host system's command line. Because the file has been encoded for mail delivery, you now have to run a decoder. At the command line, type uudecode file.name where file.name is the file you created while in mail. Uudecode will create a new, uncompressed binary file. In some cases, you may have to run it through some other programs (for example, if it is in "tar" form), but generally it should now be ready for you to download to your own computer (on which you might then have to run a de-compressor program such as PKUNZIP). Now if somebody sends you a MIME attachment, retrieving the attachment is simple. In both pine and elm, you'll be asked if you want to save the attachment to a file. If you answer by hitting your y key, you'll be asked for a file name to save it under (or just hit enter to save it under the default name suggested by the computer). You can now retrieve the file by exiting mail and then using the techniques listed in Chapter 4 for downloading Usenet files. All this brings up a related issue. Say somebody sends you a plain old e-mail message that you want to transfer to your own computer (as opposed to an encoded file). Assuming you're connected to a Unix public- access site, and that the message is straight ASCII, you have a couple of options. The quick and dirty way is to start your computer's screen-capture or logging function before you open the message. Then call up the message and, when done, stop the logging, and the file's saved to your computer. That method's good if you only want to transfer one message. But what if you want to save several messages to a single file (a bunch of items from a mailing list, say)? Then you might want to save them to a file on your public-access site first and then download that. If you use the Pine mail program, open up the message and then hit your e key. You'll be asked to enter a file name in your home directory. Once done, go to the next message and repeat the process. When finished, you'll have a single large file in your home directory for downloading. Note that when you do this, Pine will mark the message for deletion, so if you want to keep it in your mailbox (to reply, perhaps), answer N when you exit pine and are asked if you want to delete the marked files. If you use elm, instead, hit your s key, either within the message or with the cursor on its entry in the message menu. You'll get something that looks like this: =jdoe which comes from the e-mail address of the sender. If you hit enter, you'll save the message to a file called jdoe in your Mail directory. If you want to save it to a differently named file in your home directory, hit your backspace key once and then type in the file name you want (but without the equal sign). As in pine, the messages will be marked for deletion, so keep that in mind if you want to retain them in your mailbox. In either case, you can now download the file, again using the comands discussed in Chapter 4 for retrieving similarly collected Usenet messages. 10.3 SENDING FILES TO NON-INTERNET SITES What if your friend only connects with a non-Unix system, such as CompuServe or MCIMail? There are programs available for MS-DOS, Apple and Amiga computers that will encode and decode files. Of course, since you can't send one of these programs to your friend via e-mail (how would she un-encode it?), you'll have to mail (the old-fashioned way) or give her a diskette with the program on it first. Then, she can get the file by e-mail and go through the above process (only on her own computer) to get a usable file. Remember to give her an encoder program as well, if she wants to send you files in return. For MS-DOS machines, you'll want to get uunecode.com and uudecode.com. Both can be found through anonymous ftp at wuarchive.wustl.edu in the /mirrors/msdos/starter directory. The MS-DOS version is as easy to use as the Unix one: Just type uudecode filename.ext and hit enter. Mac users should get a program called uutool, which can be found in the info-mac/util directory on sumex-aim.stanford.edu. Think twice before sending somebody a giant file. Although large sites connected directly to the Internet can probably handle mega-files, many smaller systems cannot. Some commercial systems, such as CompuServe and MCIMail, limit the size of mail messages their users can receive. Fidonet doesn't even allow encoded messages. In general, a file size of 30,000 or so bytes is a safe upper limit for non-Internet systems. 10.4 GETTING FTP FILES VIA E-MAIL To help people without ftp access, a number of ftp sites have set up mail servers (also known as archive servers) that allow you to get files via e-mail. You send a request to one of these machines and they send back the file you want. As with ftp, you'll be able to find everything from historical documents to software (but please note that if you do have access to ftp, that method is always quicker and ties up fewer resources than using e-mail). Some interesting or useful mail servers include: mail-server@rtfm.mit.edu Files of "frequently asked questions" related to Usenet; state-by-state lists of U.S. representatives and Senators and their addresses and office phone numbers. archive-server@cs.widener.edu Back copies of the Computer Underground Digest and every possible fact you could want to know about "The Simpsons." netlib@uunet.uu.net Programs for many types of personal computers; archives of past postings from many Usenet newsgroups. archive-server@ames.arc.nasa.gov Space-related text and graphics (GIF-format) files. service@nic.ddn.mil Detailed information about Internet. Most mail servers work pretty much the same -- you send an e-mail message that tells them what file you want and how you want it sent to you. The most important command is "send," which tells the computer you want it to send you a particular file. First, though, you'll need to know where the mail server stores that file, because you have to tell it which directory or sub-directory it's in. There are a couple of ways to do this. You can send an e-mail message to the archive-server that consists of one line: index The server will then send you a directory listing of its main, or root directory. You'll then have to send a second message to the archive server with one line: index directory/subdirectory where directory/subdirectory is the directory path for which you want a listing. An alternative is to send an e-mail message to our old friend archie, which should send you back the file's exact location on the archive-server (along with similar listings for all the other sites that may have the file, however) Once you have the file name and its directory path, compose a message to the archive server like this: send directory/subdirectory/file Send off the message and, anywhere from a few minutes to a couple of days later, you'll find a new message in your mailbox: a copy of the file you requested. The exact time it will take a file to get to you depends on a variety of factors, including how many requests are in line before yours (mail servers can only process so many requests at a time) and the state of the connections between the server and you. Seems simple enough. It gets a little more complicated when you request a program rather than a document. Programs or other files that contain unusual characters or lines longer than 130 characters (graphics files, for example) require special processing by the mail server to ensure they are transmitted via e-mail. Then you'll have to run them through at least one converter program to put them in a form you can actually use. To ensure that a program or other "non-mailable" file actually gets to you, include another line in your e-mail message to the server: encoder This converts the file into an encoded form. To decode it, you'll first have to transfer the file message into a file in your home directory. One further complication comes when you request a particularly long file. Many Net sites can only handle so much mail at a time. To make sure you get the entire file, tell the mail server to break it up into smaller pieces, with another line in your e-mail request like this: size 100000 This gives the mail server the maximum size, in bytes, of each file segment. This particular size is good for UUCP sites. Internet and Bitnet sites can generally go up to 300000. When you get all of these files in mail, transfer them to your home directory. Exit mail and call up each file in your host system's text processor and delete each one's entire header and footer (or "signature" at the end). When done with this, at your host system's command line, type cat file1 file2 > bigfile where file1 is the first file, file2 the second file, and so on. The > tells your host system to combine them into a new megafile called bigfile (or whatever you want to call it). After you save the file to your home directory (see section 10.2 above), you can then run uudecode, tar, etc. One word of caution, though: if the file you want is long enough that it has to be broken into pieces, think of how much time it's going to take you to download the whole thing -- especially if you're using a 2400-baud modem! There are a number of other mail servers. To get a list, send an e-mail message to mail-server@rtfm.mit.edu: send usenet/comp.sources.wanted/How_to_find_sources_(READ_THIS_BEFORE_POSTING) You'll have to spell it exactly as listed above. Some mail servers use different software, which will require slightly different commands than the ones listed here. In general, if you send a message to a mail server that says only help you should get back a file detailing all of its commands. But what if the file you want is not on one of these mail servers? That's where ftpmail comes in. Run by Digital Equipment Corp. in California, this service can connect to almost any ftp site in the world, get the file you want and then mail it to you. Using it is fairly simple -- you send an e-mail message to ftpmail that includes a series of commands telling the system where to find the file you want and how to format it to mail to you. Compose an e-mail message to ftpmail@decwrl.dec.com Leave the "subject:" line blank. Inside the message, there are several commands you can give. The first line should be reply address where "address" is your e-mail address. The next line should be connect host where "host" is the system that has the file you want (for example: wuarchive.wustl.edu). Other commands you should consider using are "binary" (required for program files); "compress" (reduces the file size for quicker transmission) and "uuencode" (which encodes the file so you can do something with it when it arrives). The last line of your message should be the word "quit". Let's say you want a copy of the U.S. constitution. Using archie, you've found a file called, surprise, constitution, at the ftp site archive.cis.ohio-state.edu, in the /pub/firearms/politics/rkba directory. You'd send a message to ftpmail@decwrl.dec.com that looks like this: reply adamg@world.std.com connect archive.cis.ohio-state.edu binary compress uuencode get pub/firearms/politics/rkba/constitution quit When you get the file in your mailbox, use the above procedure for copying it to a file. Run it through uudecode. Then type uncompress file.name to make it usable. Since this was a text file, you could have changed the "binary" to "ascii" and then eliminated the "uuencode" file. For programs, though, you'll want to keep these lines. One caveat with ftpmail: it has become such a popular service that it could take a week or more for your requested files to arrive. 10.5 MINING FOR INFO ON USENET VIA E-MAIL