Content-Type是CGI传给客户端的数据的格式，如果没有定义Content-Type，程序就会认为"Hello World !!"是Content-Type，这样网页上会报 Internal Server Error 错误信息，而且Apache的error_log中会有错误信息：

df. Premature end of script headers

Perl提供了CGI模块，调用模块中的函数，可以更加方便的编写CGI程序。

#!/usr/bin/perl -wt
use strict;
use CGI;
 
{
  my $q = new CGI;
  print $q->header(),
  $q->start_html("hello perl world!"),
  $q->h1('hello perl world'),
  $q->end_html();
}

定义页面中文编码：

df. print $cgi->header("text/html; charset=gb2312");

下面是一个比较完整的例子，读取并打印WEB服务器变量：

#! /usr/bin/perl -w
 
print "Content-type: text/html", "\n\n";
print "", "\n";
print "", "\n";
print "
About this Server
", "\n";
print "
";
print "Server Name: ", $ENV{'SERVER_NAME'}, "
", "\n";
print "Running on Port: ", $ENV{'SERVER_PORT'}, "
", "\n";
print "Server Software: ", $ENV{'SERVER_SOFTWARE'}, "
", "\n";
print "Server Protocol: ", $ENV{'SERVER_PROTOCOL'}, "
", "\n";
print "CGI Revision: ", $ENV{'GATEWAY_INTERFACE'}, "
", "\n";
print "
", "\n";
print "", "\n";
exit (0);

和其它CGI程序一样，Perl也能够处理输入参数，例如：showname.pl?name=liaojl

#!/usr/bin/perl -w
use CGI qw/:standard/;
 
{
  my $cgi= new CGI;
  print $cgi->header,
  $cgi->start_html('A Simple Example'),
  $cgi->h1('A Simple Example');
 
  if ( $cgi->param())
  {
    print "Your name is ",
    $cgi->param('name');
  }
 
  $cgi->end_html();
}