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

my @files;
my @ignore=(
  '/usr/bin/',
  '/home',
);
iterate_dirs(
  # entscheiden ob das Verzeichnis besucht werden soll
  sub{
   for(@ignore)
   { return 0 if( index($_[1],$_)==0 ); }
   return 1 if( -r $_[0] );
   return 0;
  },

  # Auswerten des Eintrags
  sub{
    push(@files, $_[1]) if( -f $_[0] and -r $_[0] and substr($_[0],-4,4) eq '.pod' );
  },

  # die zu durchsuchenden Verzeichnisse
  '/usr/lib/perl5'
);

print "$_\n" for( @files );

#################################

sub iterate_dirs {
  my ($decide_code, $each_code, @stack ) =@_ ;

  my $dir=getcwd;

  my ($p,$dh,$path,$tmp);
  while(@stack)
  {
    $path = pop(@stack);
    chdir( $path ) or die "chdir($path) failed: $!";;
    opendir( $dh, '.' ) or die "Unable to open $path: $!\n";
    for( readdir( $dh ) )
    {
      next if( $_ eq '.' or $_ eq '..' );
      $tmp=$path.'/'.$_;
      push(@stack, $tmp) if( -d $_ and $decide_code->( $_, $tmp ) );
      $each_code->( $_, $tmp );
    }
    closedir ($dh);
  }

  chdir ( $dir ) or die "chdir($dir) failed: $!\n";
  return 1;
}