#!/usr/bin/perl -w
use strict;
my ($dir,$file,$old,$new);
print "Enter Directory path: ";
$dir = <STDIN>;
print "Enter filename: ";
$file = <STDIN>;
print "Enter old pattern: ";
$old = <STDIN>;
print "Enter new pattern: ";
$new = <STDIN>;
chomp ($dir,$file,$old,$new);
opendir (DIR, "$dir") || die $!;
my @files = readdir(DIR);
foreach my $filename( @files)
{
if ("$file" =~ "$filename")
{ open (FH, "$file") || die "cant open file $!";
my @lines = <FH>;
print @lines;
foreach (@lines)
{
if (grep /"$old"/, $_)
{ s/"$old"/$new"/g;
print $_;
}}
}}