#!/usr/bin/perl
use strict;
use warnings;
use Time::Local;

my $out='out-perl.dat';
open my $OUT, '>', $out or die "unable to open $out !";

my $start;
my $finish;

foreach my $text_file (<*.txt>) {
  print STDOUT "working on file $text_file\n";
  $start = time();
  
  open(my $IN, '<', $text_file) or die "invalid file: $text_file !";
  
  # reading entire file line by line << 1 second overhead
  while (<$IN>)
  {
    tr/-!"#%&'()*,.\/:;?@\[\\\]_{}0123456789//d;
    s/w(as|ere)/be/gi;
    s/\sneed.*/ need /gi;
    s/\s.*meant.*/ mean /gi;
    s/\s.*work.*/ work /gi;
    s/\s.*read.*/ read /gi;
    s/\s.*allow.*/ allow /gi;
    s/\s.*gave.*/ give /gi;
    s/\s.*bought.*/ buy /gi;
    s/\s.*want.*/ want /gi;
    s/\s.*hear.*/ hear /gi;
    s/\s.*came.*/ come /gi;
    s/\s.*destr.*/ destroy /gi;
    s/\s.*paid.*/ pay /gi;
    s/\s.*selve.*/ self /gi;
    s/\s.*self.*/ self /gi;
    s/\s.*cities.*/ city /gi;
    s/\s.*fight.*/ fight /gi;
    s/\s.*creat.*/ create /gi;
    s/\s.*makin.*/ make /gi;
    s/\s.*includ.*/ include /gi;
    s/\s.*mean.*/ mean /gi;
    s/\stalk.*/ talk /gi;
    s/\sgoing / go /gi;
    s/\sgetting / get /gi;
    s/\sstart.*/ start /gi;
    s/\sgoes / go /gi;
    s/\sknew / know /gi;
    s/\strying / try /gi;
    s/\stried / try /gi;
    s/\stold / tell /gi;
    s/\scoming / come /gi;
    s/\ssaying / say /gi;
    s/\smen / man /gi;
    s/\swomen / woman /gi;
    s/\stook / take /gi;
    s/\stak.*/ take /gi;
    s/\slying / lie /gi;
    s/\sdying / die /gi;
    s/\smade /make /gi;
    s/\sused.*/ use /gi;
    s/\susing.*/ use /gi;

    print $OUT "$_";
  }
}

$finish = time();

my $total_seconds = $finish-$start;
my $minutes = int ($total_seconds/60);
my $seconds = $total_seconds - ($minutes*60);

print "minutes: $minutes  seconds: $seconds\n";

__END__
working on file nightfall.txt
minutes: 1  seconds: 34