
How can I convert map addresses into latitude longitude?I'm trying to write a shell script that will accept a street address and output the latitude and longitude of that address, for geocache purposes. How can I do that? This is a pretty interesting problem because while there are a variety of ways you can ostensibly get your latitude and longitude for a specific address from somewhere like Google Maps, the data isn't always accurate and it's also often pretty darn hard to figure out. Heck, one of the most common ways to get lat/long from a Google Map is to cut and paste a Javascript snippet into your browser address bar. Ugh. Fortunately, after much digging around, I found that there's not only a nice API for Yahoo Maps, but that there's a lazy way you can access it via a shell script. The key piece is the Yahoo Maps URL: http://api.maps.yahoo.com/ajax/geocode?appid=onestep&qt=1&id=m&qs=
Let's step through how it works, using an address you might have bumped into a few times in the past, and then I'll show how it can be turned into a simple Linux or Unix shell script. $ lynx -dump 'http://api.maps.yahoo.com/ajax/geocode?appid=onestep&qt=1&id=m&qs=1600+pennsylvania+ave+washington+dc'
YGeoCode.getMap({"GeoID":"m","GeoAddress":"1600 pennsylvania ave washington dc","GeoPoint":{"Lat":38.89859,"Lon":-77.035971},"GeoMID":false,"succes s":1},1); The address is 1600 Pennsylvania Ave, Washington DC and I would like to think that everyone knows who lives there. Note that I'm using "lynx" to dump the result of that URL query to standard output and that the output is split across three lines. The key data item here is GeoPoint because immediately following are the Lat and Lon values (in this case 38.89859 and -77.035971). We can experimentally verify this by entering these two points into Google Maps too: ![]() Yup, it's the lat/long for the White House in Washington DC. Back to the script, though. Using "lynx" (or "get" or "curl") we now have a quick and easy way to convert a street address into a latitude / longitude pair. So there's just stuff to wrap around it. For example, convert a simple address into a URL-friendly address. Pretty easy: addr="$(echo $1 | sed 's/ /+/g')"
It's a lazy way to accomplish this goal (e.g., turn spaces into "+" symbols), but let's just keep moving and let it ride. Next up, call the Yahoo API and save just the line that contains the GeoPoint data: val="$(lynx -dump "$converter$addr" | grep "GeoPoint" )"
Finally, we have the line that contains the lat/long we want. How do we extract just that data? With my favorite Linux command: "cut": lat="$(echo $val | cut -d: -f3 | cut -d, -f1)"
long="$(echo $val | cut -d: -f4 | cut -d\} -f1)" Now we've got it! All that's left is to output it: echo "$long,$lat"
Put all the lines together and you now have a very simple command that does exactly what you seek: $ sh geomap.sh "1600 pennsylvania ave, washington dc"
38.89859,-77.035971 Hope that helps you out. Oh, and assembling all the discrete lines into a script is a simple task "best left for the reader". :-)
Help others find this article at Del.icio.us, Digg, Netscape, Reddit, and Stumble Upon
Categorized:
Shell Script Programming
(Article 8845)
Tagged: geocache, latitude longitude, linux, shell script, unix Previous: 28 Smart Ways to Overcome the Recession Next: How do I create a KML map data file? Subscribe!
Never miss another useful Q&A article again! Subscribe to AskDaveTaylor with Google Reader. sweet! thanks dude! Posted by: frogola at September 30, 2009 9:17 AMI have a lot to say, but ...
I do have a comment, now that you mention it!
|
![]()
Search
Find just the answers you seek from among our 2300+ free tech support articles by using our Lijit search engine.
Help!
Subscribe to
Ask Dave Taylor!
Free Updates!
Sign up and get free weekly updates and special offers on books, seminars, workshops and more.
Articles and Reviews
Auctions and Online Shopping Blogs and RSS Feeds Building Web site traffic Business and Management Cell Phones and Mobile Phones CGI Scripts and Web Site Programming Computer and Internet Basics d) None of the Above HTML and CSS Industry News and Trade Shows Mac OS X Help MySpace, Facebook, Twitter and Social Network Help Pay Per Click (PPC) Search Engine Optimization Shell Script Programming Sony PSP, MP3 Players, Etc. The Writing Business Unix and Linux Help Video Game Tips and Help Windows Help
Recent Entries
Book Links
|