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

#test file to learn how to process multiple files at once

#first get the path for current directory
my $dir = '.'; # current working directory

#open and read only the .txt files
opendir my $DIR, $dir or die "Cannot open '$dir' because: $!";
my @textFiles = grep /\.txt\z/, readdir $DIR;
closedir $DIR or die "Could not close '$dir' because: $!";

#open each file for further processing
foreach my $text_file ( @textFiles ) {
    open my $text_file_fh_in, '<', $text_file or die "Cannot open '$text_file' because: $!";  #open for reading

    #create the names of the new files
    my $text_file_out = $text_file;
    $text_file_out =~ s/(?=\.txt\z)/_new/;

    open my $text_file_fh_out, '>', $text_file_out or die "Cannot open '$text_file_out' because: $!";  #open for writing

    #tests to see if it works
    #print "$text_file\n"; 
    print "$text_file_fh_in\n";
    #print "$text_file_out\n"; 
    print "$text_file_fh_out\n";

    while ( <$text_file_fh_in> ) {
        if ( /^(.*?)\.(.*?)\ (.*?)\.(.*?)\ (.*?)$/ ) {
            print $text_file_fh_out "$1\t$2\t$4\t$5\n";
        } 
    }

    #close the filehandles
    close $text_file_fh_in or die "Could not close '$text_file' because: $!";  
    close $text_file_fh_out or die "Could not close '$text_file_out' because: $!";
}