#!/usr/bin/perl;
use strict;

# I have the text file named as data.txt.

my $infile = 'data.txt';

# Now i like to read the line from data.txt
 
open IN,'<',$infile or die "$!";
print "Reading from '$infile'\n";
my $dir;
while (<IN>){
  chomp;

  # in which the line 
  # starts with ZERO 
  # contains the directory path?

  if (/^ZERO:(.*)/){
    $dir = $1;
  }
}
close IN;
print "Directory is '$dir'\n";
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What's the problem, which part couldn't you do ?