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

my $gsc = 'C:\Program Files\gs\gs9.05\bin\gswin64c.exe';
my $dpi = '150';
my $txt = '4';
my $bld = '4';
my $ein='C:\Lokale Daten\vbv tiffs\Work\Spool\\';
my $aus='C:\Lokale Daten\vbv tiffs\Work\Tiff\\';

# 10 Prozesse gleichzeitig starten
my $max_run=10;

my @cmd=($gsc,'-q', '-dSAFER', '-dNOPAUSE', '-dBATCH', '-sDEVICE=tiffg4', '-r'.$dpi, '-dTextAlphaBits='.$txt, '-dGraphicsAlphaBits='.$bld);

# PID aller laufenden Kindprozesse
my %running;
# Kommandos die auf Ausfühung warten.
my @waiting;

# bendete Kindprozesse terminieren
$SIG{CHLD}=sub{
    my $pid=wait();
    delete($running{$pid});
  };


die("Error open $ein ($!)\n") unless (opendir(my $dh,$ein));

while (my $Eintrag = readdir($dh))
{
  my $infile  = File::Spec->join($ein,$Eintrag);
  next if(-d $infile);
  if($Eintrag =~ /\.ps$/)
  {
    my $outfile = File::Spec->join($aus,$Eintrag.'.tif');

    print "ADD $infile\n";

    my @c=@cmd;
    push(@c,'-sOutputFile="'.$outfile.'"');
    push(@c,'-f "'.$infile.'"');
    push(@waiting,\@c);
  }
  Start(\%running,\@waiting,$max_run);
}
closedir($dh);

my $last=-1;
while(@waiting || %running)
{
  Start(\%running,\@waiting,$max_run);
  select(undef,undef,undef,0.10);

  my $now=int(@waiting/100);
  if($now != $last)
  {
    $last=$now;
    print "TIME:".localtime()."\n";
    print "WATITING FOR EXEC: ".@waiting."\n" ;
    print "PROCESSES RUNNING: ".keys(%running)."\n";
    print "\n";
  }
}

########################################################################
########################################################################
sub Start
{
  my $run=shift;
  my $wait=shift;
  my $max=shift;

  while(keys(%$run) < $max)
  {
    return unless(@$wait);
    my $cmd=shift(@$wait);

    print "START: ".join(' ',@$cmd)."\n";

    my $pid=fork();
    die("Fork Failed $!\n") unless(defined($pid));
    unless($pid)
    {
      exec(@$cmd);
      die("EXEC Failed");
    }
    $run->{$pid}=1;
  }
}