Sunday, July 22, 2007

unix shell is still one of my favorite

unix shell is so easy and powerful, just like vi.
It is always my favorite.
the following example shows how to change variable in unix shell to lower case and remove file extension

for f in *.shp
#change to lower case
file_name=`echo $f | sed 'y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/'`
#remove file extension to use as table name
echo "table name: $table_name"

Tuesday, July 3, 2007

Production GIS map system all based on open source components

During the past weeks, I was designing a GIS map system similar to Google map for a company.
On the server side, they want a spatial database, which support ESRI format Sharp files. Also needs a map server, which handle client request, query the database...etc.

On the client side, they want a standalone client instead of AJAX based web app.

I have some experience on the GIS stuff five years ago. We used a open source map server at that time, but it was quite slow.

When looking into open source area for GIS system again after five years, i found that we can build PRODUCTION GIS system by integrating all the latest and best from open source community.

Here is the solution in the end:
Server side: Postgis + GeoServer + squid cache.
No development work is needed .

Client side:
  • Web-based client, can be built on top of OpenLayers
  • standalone client, can be built by extending from udig. udig is an eclipse RCP application!