63 Keeping Track of the Weather


#63 Keeping Track of the Weather

Another straightforward use of website scraping that illustrates yet a different approach is a weather forecast tool. Specify a zip code, and this script goes to the Census Bureau to obtain population and latitude/longitude information. It visits AccuWeather to extract the current weather in that region.

The Code

 #!/bin/sh # weather - Reports the weather forecast, including lat/long, for a zip code. llurl="http://www.census.gov/cgi-bin/gazetteer?city=&state=&zip=" wxurl="http://wwwa.accuweather.com" wxurl="$wxurl/adcbin/public/local_index_print.asp?zipcode=" if [ "" = "-a" ] ; then   size=999; shift else   size=5 fi if [ $# -eq 0 ] ; then   echo "Usage: 
 #!/bin/sh # weather - Reports the weather forecast, including lat/long, for a zip code. llurl="http://www.census.gov/cgi-bin/ gazetteer ?city=&state=&zip=" wxurl="http://wwwa.accuweather.com" wxurl="$wxurl/adcbin/public/local_index_print.asp?zipcode=" if [ "$1" = "-a" ] ; then size=999; shift else size =5 fi if [ $# -eq 0 ] ; then echo "Usage: $0 [-a] zipcode " >&2 exit 1 fi if [ $size -eq 5 ] ; then echo "" # Get some information on the zip code from the Census Bureau lynx -source "${llurl}$1"  \ sed -n '/^<li><strong>/,/^Location:/p'  \ sed 's/<[^>]*>//g;s/^ //g' fi # The weather forecast itself at accuweather.com lynx -source "${wxurl}$1"  \ sed -n '/<font class="sevendayten">/,/[^[:digit:]]<\/font>/p'  \ sed 's/<[^>]*>//g;s/^ [ ]*//g'  \ uniq  \ head -$size exit 0 
[-a] zipcode" >&2 exit 1 fi if [ $size -eq 5 ] ; then echo "" # Get some information on the zip code from the Census Bureau lynx -source "${llurl}" \ sed -n '/^<li><strong>/,/^Location:/p' \ sed 's/<[^>]*>//g;s/^ //g' fi # The weather forecast itself at accuweather.com lynx -source "${wxurl}" \ sed -n '/<font class="sevendayten">/,/[^[:digit:]]<\/font>/p' \ sed 's/<[^>]*>//g;s/^ [ ]*//g' \ uniq \ head -$size exit 0

How It Works

This script provides yet another riff on the idea of using a shell script as a wrapper, though in this case the optional flag primarily changes the amount of information filtered through the head at the end of the pipe. This script also takes advantage of the natural source code organization of the two sites to slice out the population and latitude/longitude data prefixed with the strings <strong> and Location: , respectively, and then it slices out the forecast information wrapped in a sevendayten font container.

Running the Script

The standard way to invoke this script is to specify the desired zip code. If census information is available for that region, it'll be displayed, and the most recent weather forecast summary will be shown too. Add the - a flag, however, and it skips the census information and reports a full ten-day forecast.

The Results

 $  weather 66207  Zip Code: 66207  PO Name: Shawnee Mission (KS) Population (1990): 13863 Location: 38.957472 N, 94.645193 W Currently at 10:35 PM CLEAR    Winds SW  at 4 mph. Temp: 28 / RF 26. UV Index 0. 

A typical winter evening in Kansas: a warm 28 degrees Fahrenheit. Brrrrr.




Wicked Cool Shell Scripts. 101 Scripts for Linux, Mac OS X, and Unix Systems
Wicked Cool Shell Scripts
ISBN: 1593270127
EAN: 2147483647
Year: 2004
Pages: 150
Authors: Dave Taylor

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