#!/usr/bin/perl
                                                                                
# Always use these
use strict;
use warnings;
                                                                                
# Edit contains the complete path of the files to be edited
my $path = "/home/rjs/heena/edit" ;
                                                                                
# Getting a file handler (and test for success/failure!)
open(FL, "<", $path) or die "unable to open data file '$path' ($!)\n";
                                                                                
# Getting all the file names in the @array so that i can process the
# file one by one
chomp(my @array = <FL>);
                                                                                
# Close the data file
close(FL);
                                                                                
# Process each file
                                                                                
foreach my $file (@array) {
    next if ($file =~ /^\s*(#|$)/);   # Skip blank/commented lines
    process_file($file);              # Process file
}
                                                                                
                                                                                
# Subroutines
sub process_file {
    my ($file) = @_;
                                                                                
    $/ = "";    # Read entire file as a single line
    my $fh;     # Declare file handle (better than using globals)
                                                                                
    # Read the file
    open($fh, "<", $file) or die "unable to read file '$file' ($!)\n";
    $_ = <$fh>;
    close($fh);
                                                                                
    # Apply the change
    s/CONFIDENTIAL(.*?)own\s+risk/ /sm;
                                                                                
    # Write the file back TO THE SAME FILENAME
    open($fh, ">", $file) or die "unable to write file '$file' ($!)\n";
    print $fh $_;
    close $fh;
}