frequently asked questions

1. What does phar mean?
2. Why did you choose such ugly URL's for your documents?
3. Redirected links on this website
4. Why did you mail me a TagMail confirmation request?
5. What is PostScript (the .ps-files)?
6. Why don't you use MS Word documents?
7. What is this weird attachment I get with your mails?
8. I never open mails with attachements... did you send me a virus in your mail attachment?

answers

1. What does phar mean?

   Short answer:

   Good question. It means nothing. It does not stand for anything I know of. I made it up. If you know of something else that is called Phar, feel free to enlighten me.

   Slightly longer answer:

   Phar is the name of a rogue spaceship in a science fiction story I once wrote. I don't know why I called it Phar. And no, you can't read the story.

   Phar does not try to be embarrassingly cool. Substituting Ph for an F is an adolescent thing to do. Phar does not actually mean far. If I wanted a domain called far, I would have registered far.ch.

2. Why did you choose such ugly URL's for your documents?

   This has something to do with persistence.

   We've all seen the infamous Error 404: File not found. As often as not, this happens because the structure of a website was rearranged and the resource in question was moved in the process.

   After breaking my website for the third time, I adopted a URL naming scheme advocated by Tim Berners-Lee in his note Cool URIs don't change to counter this problem. Basically, the idea is to use the date on which a resource was made public on the internet as the URI for this resource. Since the date of publication never changes, the URI is persistent.

   My short, nice-looking, human-readable URI's such as www.phar.ch/contact are only a snapshot of the current state of my website. Use the date-like URI's to link to this site and I guarantee these links will only break when I'm out of money and can't pay for server space any more.

3. Redirected links on this website

   Occasionally, I post links on my website that, when clicked, will redirect you to this faq entry, instead of delivering the actual resource.

   I do this because I believe the target to be a questionable or even a dangerous resource. This may be because it spreads disinformation, preaches hate or racism, or simply because I personally despise it.

   I am aware that I'm making a subjective judgement here; you may not have a problem with the resource in question. But remember that I do not keep anybody from accessing the resource. I simply choose not to link to it directly. I give you the URL as the name of the link, so you can still follow it by a copy/paste into your browser's location bar.

   I simply decline to contribute to a better Google page ranking for the resource.

4. TagMail confirmation requests

   I am employing a software agent called TagMail to filter out spam from my e-mails. When TagMail encounters a message from someone it doesn't know about, it sends back a confirmation request which reads something like:

   Hi, I'm TagMail, an automated agent filtering mail for Pascal Schuppli. ...

   Simply reply to this message and TagMail will never bother you again. Until you do reply, however, I won't read your e-mail because TagMail keeps it out of my mailbox until it gets a confirmation from you!

   The idea behind this scheme is that a spammer won't use a real e-mail address and thus won't be able to confirm this message, thus keeping my inbox spam-free.

   There is a downside to this, of course. For every spam mail TagMail processes, it sends out a confirmation request. This generates even more e-mail traffic. It gets worse: If the address the spammer used is actually valid, someone will get a confirmation request from me even though he didn't send me an e-mail. If you did get a confirmation request without having sent me an e-mail, I'm really sorry, but please remember that this happened because someone used your e-mail address to send me mail in your name.

5. What is PostScript?

   So you're here because you got a .ps-file from me and you have no clue whatsoever how to display it, or print it.

   Basically, PostScript is the (very) big brother of pdf. It's an actual programming language, used as the standard printing format on unix systems and derivates. Many laser printers directly support PostScript. PostScript is also used in the professional printing industry.

   There's a great many articles about PostScript. There's even a couple of heavy books on the topic. That's all beside the point, though. How do you display and print a PostScript file?

   If you're asking this question, chances are you're not coming from a Unix background. In fact, you're probably working with Windows. Well, good news: You can display and print PostScript files even with Windows.

   Here's how: Visit the GhostScript project and download GSView. You can compare this software to the Adobe Acrobat Viewer, only GhostView is also capable of viewing (and printing) PostScript files. And, of course, it's free of charge.

6. Why don't you use word documents?

   There are several reasons for this:

   • I am using the free (think speech, not beer) Linux operating system, which does not run Microsoft Word and only marginally supports the Word document format. (Update: MS Word now more or less runs under Wine)
   • There are better document formats available, most of them highly portable. HTML, PostScript, TeX, RTF, plain text... you name it. The specifications for these formats are available to the public.
   • I'm using LaTeX for most of my writing. LaTeX is a high-quality typesetting program; it is available for most platforms and is fairly simple to learn. Documents written for LaTeX are highly portable, small, and can be edited with any editor. LaTeX produces .dvi (device-independent) files, which in turn can easily be converted, but not to MS Word format.
   • LaTeX and PostScript beat the crap out of MS Word. Don't take my word for it. Try it. There's also MikTeX, a TeX for Windows.

7. What is this weird attachment I get with your mails?

   Does the weird attachment look somewhat like this:

   --=-CY691Yrrff+J4wakpVis
   Content-Type: application/pgp-signature; name=signature.asc
   Content-Description: This is a digitally signed message part
   
   -----BEGIN PGP SIGNATURE-----
   Version: GnuPG v1.0.6 (GNU/Linux)
   Comment: For info see http://www.gnupg.org
   
   iD8DBQA8uFtGa41lC+0zLIARAuKcAJ4o2v7H7u5vUISim217C3VlfeR6CwCdHqva
   s2LchYzp0T9zbBvE6FzGOe8=
   =TqXD
   -----END PGP SIGNATURE-----
   
   --=-CY691Yrrff+J4wakpVis--
   

   This is a digital signature. A digital signature is much like a real signature; it proves to the recipient that the mail really was sent by the guy who signed.

   Digital signatures can do even more: They also guarantee that the mail you have received is unaltered. Digital signatures prevent forgeries.

   How do digital signatures work?

   With asymmetric cryptography. This means that you need one key to encrypt a message, and another key to decrypt it. You make one of these keys public and keep the other one private. Now, if you encrypt something with your private key, only your public key will decrypt it again.

   The mumbo jumbo mess you see above is a checksum (hash) of the body of a mail message that I sent. The checksum is encrypted with my private key. If you know my public key, you can decrypt the mumbo jumbo block and compare the checksum with a checksum you calculate from the actual mail message. If the two match, you have a genuine mail message from me. If they don't, then the mail is a forgery.

   Of course, there are programs which take care of all this for you. They are available for most platforms. They also allow you to encrypt the contents of your mail, so you can actually have private conversations with anyone who uses the same protocol.

8. I never open mail with attachments... did you send me a virus in your mail attachment?

   Considering how many viruses are spread in e-mail attachments by broken mail clients, this may be the smart thing to do for you. However, if you're worried about the digital signature attached to a mail you got from me, rest assured that it is completely harmless. It is just an encrypted checksum. There is no exectuable code there. If you don't know how to verify digital signatures and don't want to learn, just ignore the attachment.