Mapping Hacks

Build Interactive Web-Based Map Applications #91

Chapter 8, Building the Geospatial Web

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HACK

/var/www/cgi-bin

A directory that your web server uses for CGI programs. Copy the

mapserv CGI program here.

/var/www/html

Your document root. This is where the initialization HTML file and the

map file (.map) should go.

/var/www/html/data

This will be the repository for your geodata files.

/var/www/html/temp

Temporary directory for images. Your web server must have write per-

mission for this directory.

The Map File

The map file is where you specify what MapServer should do. Here is possi-

bly the simplest map file that will display a shapefile:

MAP

SIZE 400 400

EXTENT -125 50 -65 24

LAYER

TYPE LINE

STATUS DEFAULT

DATA "/var/www/html/data/statesp020.shp"

CLASS

COLOR 0 0 0

END

END

END

Each section of the map file starts with the name of that section and ends

with the word

END. Some sections can be nested. This map file says to create

an image 400 pixels wide by 400 pixels high that covers the Continental

United States, from 65º W to 125º W and from 24º N to 50º N.

One map layer will be shown, and it is the shapefile of the state boundaries.

It will be presented in the color black; the colors are RGB triples, so

25000

is all red, 0 255 0 is green, 0 0 255 is blue, and there are 2

24

more shades of

color available.

Name this file mini.map and make sure that the statesp020.shp, .shx, and .dbf

files are in the data