#!perl -w

use strict;
use Data::Dumper;

my $prog=$0;
my ($estat,$infile,$errfile,$action,$sub,$thishost,$pid,$cpid,$pidstat,$thiskey);
my (%track,%closed);

my $max=2;
my $rcount=0;
my $tcount=0;

$infile=$ARGV[0];
open(IN,'<',$infile) || die "cannot open input file $infile \"$!\"";

sub _sleep {
 sleep int(rand(10));
 return $?>>8;
}

sub _waitpid {
 my $cpid=waitpid(-1,0);
 my $pidstat=$? >> 8;
 $closed{$track{$cpid}}=$pidstat;
 $rcount--;
}

#here
while (<IN>) {
#for (<IN>) {
 chomp;

 $rcount++;
 $tcount++;
 print "Progress: $tcount\r";
 $pid = fork;

 if ($pid==0) {
 # child
  close IN;
  # start call sleep sub
  my $estat=_sleep;
  exit $estat;
  # end call sleep sub

  # start direct sleep
  #sleep int(rand(10));
  #exit $?>>8;
  # end direct sleep
 }
 else {
 # parent
  $track{$pid}=$_;
  if ( $rcount >= $max ) {
   # start call waitpid sub
   _waitpid();
   # end call waitpid sub
   # start direct waitpid
   #my $cpid=waitpid(-1,0);
   #my $pidstat=$? >> 8;
   #$closed{$track{$cpid}}=$pidstat;
   #$rcount--;
   # end direct waitpid
  }
  else {
  }
 }
}

print "\n\nWaiting for procs to finish...\n";
while ($rcount>0) {
 _waitpid();
}
print "Done\n";

for $thiskey (keys %closed) {
 print "$thiskey $closed{$thiskey}\n";
}
print Dumper(\%closed);

close IN;
print "End\n";