#!/usr/bin/perl -w  #Path to perl interpreter.
use strict; #The strict pragma.

my @link_array; #Declare an array named link_array.
@ARGV = "test1001.html"; #The file on the 'command line'.
while(<>) #Does the file still have content?
{

  s/<(?:[^>'"]*|(['"]).*?")*>//gs; #Remove all HTML tags.
  s/^(\s+)//g; #Remove all leading whitespace.
  
  #If a match is found, add it to the end of the array.
  #The search is global and case-insensitive.
  push @link_array, $_ if(/^http:/gi);
  push @link_array, $_ if(/^ftp:/gi);
  push @link_array, $_ if(/^mailto:/gi);
} #End of the while loop.

open( FH, ">>links.txt" );  #Open the file links.txt for
                            #appending.
print FH @link_array, "\n"; #Write the links we found to
                            #the file.

close FH;  #Close the file handle.