perl的cgi基础实例

#!/usr/bin/perl -wT
#should use strict and warnning
use warnings;
use strict;
use CGI;
#to debug error
use CGI::Carp qw(warningsToBrowser fatalsToBrowser);
#or debug from command line by : perl -cwT yourcgi.cgi
#or debug by : tail /var/log/apache/error_log
#make sure yourcgi.cgi is world excutable or 755 permission
#just include sub features of cgi, standard means, 'html2', 'html3', 'html4', 'form' and 'cgi'.
#use CGI qw(:standard);

#must define and initialize
my $p1='';
my $p2='';
my $name='';
my $url='';
my $q = new CGI;
$p1   = $q->param('p1') if $q->param('p1');
$p2   = $q->param('p2') $q->param('p2') ;
$name = $q->param('name') $q->param('name') ;
$url  = $q->param('url') $q->param('url');

print $q->header();
print $q->start_html(-title=>"Hello World");

print "p1:$p1<br>";
print "p2:$p2<br>";
if(!defined($p2)){print "p2 is not defined<br>";}
if($p2 eq ""){print "p2 is empty<br>";}

print <<EndHTML;
<h2>Hello</h2>
<p>
My name is $name, and my web url is
<a href="$url">$url</a>.
</p>
EndHTML

$q->h3('welcome to here!<br>');
print "$ENV{REMOTE_ADDR}<br>";
print $q->end_html();