tinyURL

Since I have never figured out how to get Outlook to not wrap outgoing messages with long friggin' links, I found this site that will create small links to a longer link. Pretty cool...

That is pretty cool. Here's a link to this thread:

http://tinyurl.com/h0x2

Very cool, but would can someone explain how this works?

Easy, there is just a database at tinyurl.com that maps a long URL (that someone feeds it) to a short code. When you link to tinyurl.com with the short code it redirects you to the URL it was given.

Even a 4 letter alpha code would allow half a million urls to be mapped, don't know how long the codes they use are.

I was wondering about that. But I could see that database getting filled rather quickly. I would imagine that sometime in the future there would have to be a time limit on the links.

Though they do have a lot of codes. You're right, even 4 digits would offer a lot, since they can use numbers, letters, upper and lower cases, and I assume that something like "0040" would be different from "004", so that gives them even more room.

Still, I would think that after a while, they'll need an expiration for the links.

I don't think they use upper and lower case letters, otherwise people are going to type them in wrong. Still, using a four digit alphanumeric code gives you 1.6 million entries. I guess when they use up the four digit codes they will just move to five digits which will give them another 58 million codes.

I guess when they use up the four digit codes they will just move to five digits which will give them another 58 million codes.

Which sounds like a lot, until you consider that one of the advertised benefits of this service is cloaking referral codes in links... I predict that they'll be expanding to six and seven digits before too long...

I think the issue here is more how well a database will hold up to that number of rows, not how many digits need to be used. Though, honestly, the size of the data being so small should benefit it greatly. Plus, it should be easy to convert the string directly into a number, making lookups trivial.

I don't think they use upper and lower case letters, otherwise people are going to type them in wrong

True, but I would hope that anyone who's using this is just copying and pasting.

The first one was makeashorterlink.com, but obviously the guys at tinyurl had a 9 character advantage! It also redirects instantly, whereas the other one has an intermediate page.

It also does a lookup on exisiting URLs - so they don't have 20000 different entries for "disney.com"

This is the earliest Usenet reference to them (slightly useless too!), and http://tinyurl.com/1 makes it obvious that the guy owns the site. Most of the early references are from him, and people on similar topics,

Gareth

Yeah, I was wondering why there was so much stuff about unicycles. Weird.