Google: the world's favourite command line

Google is, essentially, a honking great unix system whose command line interface is addressed through URLs. This came to mind preparing the embedded map for the G3 Systems post; Google Maps autogenned a slightly different location than the view I wanted every time, although I could link directly to the right view.

So, of course, I started fiddling with it; the embedded map function seems to work as follows. Here's some code:

iframe width="425" height="350" frameborder="0" scrolling="no" marginheight="0" marginwidth="0" src="http://maps.google.co.uk/?q=Byron+Industrial+Estate,+Brookfield+Rd,+Arnold,+Nottingham,+NG5+7ER&
ie=UTF8&t=k&om=1&ll=53.001614,-1.119962&spn=0.001834,0.008476&
z=17&iwloc=addr&output=embed&s=AARTsJqS0vJdXgvvmSH9pm0agdKb_l1g-Q">/iframe>
small>ah ref="http://maps.google.co.uk/?q=Byron+Industrial+Estate,
+Brookfield+Rd,+Arnold,+Nottingham,+NG5+7ER&ie=UTF8&t=k&om=1&ll=53.001614,-1.119962&spn=0.001834,0.008476&
z=17&iwloc=addr&source=embed" style="color:#0000FF;text-align:left">View Larger Map/a>/small>

Some tags have been disabled. OK, so we kick off by declaring an iFRAME whose dimensions match what appears to be an emerging standard; anything you embed in a website is usually 425 by 350 pixels for some reason. Its content is to be drawn from the URL that follows, and a link to a near-identical page is provided beneath.

To kick off, after the ? sign that signals the end of the real URL and the beginning of the command-line argument, we've got the command q, which permits you to pass search terms, each string separated by commas and multi-word strings concatenated with + signs (just like in Python). In this case the search is an address. An & marks the end of the statement. Then there's ie which specifies encoding for the target page, in this case UTF8. Again, the statement is ended with the delimiter &, and the next one begins with a semicolon.

Next we have t, which I reckon specifies the type of map to display as its value here is k, as in KeyHole. Then there's om, set to 1; I don't know what it does. ll is crucial, as it passes the latitude and longitude of the map centre, separated by a comma, like this: 53.001614,-1.119962. spn appears to contain geographic data as well, but I'm not sure what. z controls the zoom level, a number with a maximum of 30. iwloc is one I don't know; output tells the machine to treat this one as an embed, and finally comes s, which looks to be a hashed unique identifier, and causes the whole thing to stop working if you omit or change it.

So, I increased z from 14 to 17, read off the lat, long and spn values from the view I wanted, and altered the code accordingly. And now it works.