A Simple Goal
August 9, 1999
Let's refresh -- the Smallville Gazette is a modest newspaper
which is "published" by a
CGI script that inserts dynamic content into a pre-baked
shell, not unlike pouring filling into a store bought pie
crust. We began last month by featuring the current date in
the Gazette's banner.
This month, as the Gazette evolves at this frightening pace,
we're even more ambitious: beyond the date, we want to add
the current temperature. Such real-time data lends a true
sense of timeliness, and more importantly, illustrates the
use of the LWP::Simple module.
Recall that the
HTML for the Gazette template
contained a placeholder for the date, which our Perl script
used as a marker for a search-and-replace operation to insert
the live date. We can expand that section of HTML to include
a placeholder for the current temperature, as well -- and
we'll also use HTML comment tags as placeholders now rather
than visible text as we did last month (for illustrative
purposes).
Excerpt from smallville.html,
the web template for the Smallville Gazette.
<div align="center">
<p>
<font face="Verdana, sans-serif">
<b><!--INSERT DATE HERE--><br>
Current temperature:
<!--INSERT WEATHER HERE--></b></font>
</p>
</div>
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The original smallville.cgi Perl script simply read
the entire smallville.html file and substituted the
live date for the "INSERT DATE HERE" placeholder,
using a Perl substitution:
Excerpt from smallville.cgi,
substituting the live date for the date placeholder.
#determine current date
($sec,$min,$hour,$mday,
$mon,$year,$wday,$yday,$isdst)=localtime(time);
$curDay=(Sunday,Monday,Tuesday,Wednesday,
Thursday,Friday,Saturday)[$wday];
$curMonth=(January,February,March,April,
May,June,July,August,September,
October,November,December)[$mon];
$liveDate="$curDay, $curMonth $mday, ".($year+1900);
#search-and-replace on date
$resultPage=~s/<!--INSERT DATE HERE-->/$liveDate/g;
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It should be clear, then, how we'll substitute the current
temperature for the temperature placeholder. What isn't so
clear is where we get the current temperature from?
The Perl You Need to Know
Simply, LWP::Simple
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