use strict;
use warnings;
use Cwd 'abs_path';

my($path) = @ARGV; ## add path to a directory

print "Input path: $path\n";
print "## no modifications to readdir output (as mentioned in the docs this is bad for filetesting)\n";
opendir(my $dh, $path) or die "Cannot open dir $path: $!\n";
while(readdir($dh))
{
  #print "Testing $_\n";
  if(-z $_)
  {
    print "File $_ is empty\n\n";
  }
  elsif(-d $_)
  {
    print "File $_ is a directory\n\n";
  }
  elsif(-f $_)
  {
    print "File $_ is a plain file\n\n";
  }
  elsif(-B $_)
  {
    print "Path $_ points\tto a binary file\n\n";
  }
  else
  {
    print "Not recognized: $_\n\n";
  }
}
closedir($dh);

print "## using abs_path\n";
opendir(my $dh1, $path) or die "Cannot open dir $path: $!\n";
while(readdir($dh1))
{
  my $abs_path = abs_path($_);
  #print "Testing $abs_path\n";
  if(-z $abs_path)
  {
    print "Path $abs_path\tpoints to an empty file\n\n";
  }
  elsif(-d $abs_path)
  {
    print "Path $abs_path\tis a directory\n\n";
  }
  elsif(-f $abs_path)
  {
    print "Path $abs_path points\tto a plain file\n\n";
  }
  elsif(-B $abs_path)
  {
    print "Path $abs_path points\tto a binary file\n\n";
  }
  else
  {
    print "Not recognized: $abs_path\n\n";
  }
}
closedir($dh1);

print "## using $path/filename\n";
opendir(my $dh2, $path) or die "Cannot open dir $path: $!\n";
while(readdir($dh2))
{
  my $abs_path_mod = abs_path("$path/$_");
  #print "Testing $abs_path_mod\n";
  if(-z $abs_path_mod)
  {
    print "Path $abs_path_mod\tpoints to an empty file\n\n";
  }
  elsif(-d $abs_path_mod)
  {
    print "Path $abs_path_mod\tis a directory\n\n";
  }
  elsif(-f $abs_path_mod)
  {
    print "Path $abs_path_mod points\tto a plain file\n\n";
  }
  elsif(-B $abs_path_mod)
  {
    print "Path $abs_path_mod points\tto a binary file\n";
  }
  else
  {
    print "Not recognized: $abs_path_mod\n";
  }
}
closedir($dh2);

print "## using $path/filename w/o abs_path\n";
opendir(my $dh3, $path) or die "Cannot open dir $path: $!\n";
while(readdir($dh3))
{
  my $path_mod = "$path/$_";
  #print "Testing $path_mod\n";
  if(-z $path_mod)
  {
    print "Path $path_mod\tpoints to an empty file\n\n";
  }
  elsif(-d $path_mod)
  {
    print "Path $path_mod\tis a directory\n\n";
  }
  elsif(-f $path_mod)
  {
    print "Path $path_mod points\tto a plain file\n\n";
  }
  elsif(-B $path_mod)
  {
    print "Path $path_mod points\tto a binary file\n";
  }
  else
  {
    print "Not recognized: $path_mod\n";
  }
}
closedir($dh3);