#!/usr/bin/perl -w 
use strict;  
use warnings; 

my @folders= ("data,power");
my @array=("./data.h","./power.h");
my $folder;
my %files_content;
my %grep_lines;

foreach $file (@array) {
open my $fh, $arr or die $!;
 $files_content{ $file } = <$fh>;
close $fh;
}

foreach $folder (@folders)
{
  foreach $filename (keys %files_content)
  {
  push @{ $grep_lines{ $filename } }, grep (/$folder/i, @{   $files_content{ $filename } });
  }
}