#!/usr/bin/env perl
print "\nReceived signal at ",scalar localtime,"\n";
sub test1
{
        $_ = 'http://www.perl.com/index.html';
        if (m#([^:]+)://(.*)#){
                print "\$1,\$2 = $1,$2 \n";
                if ($2 =~  m#([^/]+)/(.*)#){
                         print "\$1,$2 \n";
                         if ($2 =~ m#([^/]+)(.*)#){
                                 print "\$1,$2 \n";
                         }
                }
                 print "\$1,$2 \n";
        }
}
&test1;

[root@master ~/perl]# ./trap.pl

Received signal at Sun Dec 15 17:32:31 2013

$1,$2 = http,www.perl.com/index.html

$1,$2 = www.perl.com,index.html

$1,$2 = index.html,

$1,index.html #退出内层作用域后，又恢复了原来的值