#!/usr/bin/perl
use warnings;
use strict;
use File::Find;

my $base_dir = 'C:\\TestData';  # put in your base directory 
my ($dirname,$filename,$line);
my (@linecolumns);

find( \&wanted, $base_dir );

sub wanted {
    return if $_ eq '.' or $_ eq '..';
    if (-d) {
        print " >>> dive into: $_\n" if -d;
		$dirname = $_;
    }
    else {
        readout_file($_);  ## call subroutine readout_file
    }
}

sub readout_file {
    my ($filename) = @_;
    open my $fh, '<', $filename or die "can't open file:$!";
    while ($line=<$fh>) {
        chomp;
        $line=~s/ /,/g;        ## OR s/ /,/g; if you want
		print $line, $/;
		push(@linecolumns,$line);
        #print $_, $/;  ## OR any other subroutine you want
		print $linecolumns[0], $/;
		print $filename, $/;
#write_output($dirname,$filename,$linecolumns[0],$linecolumns[3]); ## call subroutine to print std template in output file
    }
 }