#! /usr/bin/perl -w

#  scr60.pl
#  How to substitute a pattern of text string from one to another 
#  at the incoming lines globally and quickly?  
#  Please use substitute feature.
#
#      s/old_pattern/new_pattern/g;        
#
#  The last "g" means globally, all occations.
#


mkdir("RESULT", 0777);             ##  Make a folder in the current directory for preparation.


open (IN, "Ref.txt");
open (OUT, ">RESULT/Ref.txt");

while (<IN>){
                   
     if(/http/){                   ##  Here!  Here!  Quick and easy Substitution.

            s/255.255.255.0/www.netaddress.net/g;
            print OUT $_; 
               
     }else{  print OUT $_;    }

}  ### closing while-loop 
close(IN);
close(OUT);