use strict;
use Cwd;

my $line;
my $count = 0;
my $dir = ("F:\\PIXX_TOOLS\\COUNT_TX\\LOG");

opendir(DIR, $dir) or die $!;
my @files = readdir(DIR);
closedir(DIR) or die $!;

foreach (@files) 
       {
    open(IN, $dir)or die $!;
    while ($line = <IN>) 
             {
              $count++ if ($line =~ /\QS\/R Sending command\E/g);
             }
        close IN;
        print "$count TX\n"; 
       }

use strict;
use Cwd;
use Tie::File;

my $line;
my $count = 0;
my $dir = ("F:\\PIXX_TOOLS\\COUNT_TX\\LOG");

opendir(DIR, $dir) or die $!;
my @files = map{$dir.'/'.$_}grep{$_ !~ /^\.\.?$/}readdir(DIR);
closedir(DIR) or die $!;

for my $file(@files){
  tie my @array,'Tie::File',$file or die $file." >> ".$!;
  if(grep{$_ =~ /$suchstring/}@array){
    print "In $file ist $suchstring vorhanden\n";
  }
  untie @array;
}