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

my $indir = 'C:/input';
my $outdir ='C:/output';

opendir(DIR, $indir) or die "can't open directory $indir $!";

foreach my $file (grep{-f "$indir/$_"}readdir DIR)
{
   open IN, '<', "$indir/$file" or die "can't open $indir/$file $!";
   my $new= "$outdir/$file";
   open OUT, '>', $new or die "can't open $new for output $!";

   while (my $string = <IN>)
   {
       undef ($/);

       while ($string =~m/(FINDINGS|COMPLICATIONS)(:)(.*?)(^[A-Z])/sgm)
       {
          print "processing $file\n";
          print OUT "$1$2\t$3";
       }
   }
close IN;
close OUT;
}

closedir(DIR);