A white dwarf is a small star composed mostly of electron-degenerate matter. Because a
white dwarf's mass is comparable to that of the Sun and its volume is comparable to that
of the Earth, it is very dense.

A white dwarf be small star composed mostly electron degenerate matter because white
dwarf mass be comparable sun IT volume be comparable earth IT be very dense

#! perl
use strict;
use warnings;
use 5.010;


use Getopt::Long;
use Pod::Usage;
use autodie;

my %opts = (
  infile  => '-',
  outfile => '-',
);
GetOptions (
  'encode|e'    => \$opts{encode},
  'decode|d'    => \$opts{decode},
  'infile|i=s'  => \$opts{infile},
  'outfile|o=s' => \$opts{outfile},
  'help|h'      => \&help,
  'man|m'       => \&man,
);

unless(
  # exactly one of these should be set
  $opts{encode} xor $opts{decode}
){
  help();
}


{
  my $infile;
  if( $opts{infile} ~~ ['-', '&0'] ){
    $infile = *STDIN{IO};
  }else{
    open $infile, '<', $opts{infile};
  }

  my $outfile;
  if( $opts{outfile} ~~ ['-', '&1'] ){
    $outfile = *STDOUT{IO};
  }elsif( $opts{outfile} ~~ '&2' ){
    $outfile = *STDERR{IO};
  }else{
    open $outfile, '>', $opts{outfile};
  }

  if( $opts{decode} ){
    while( my $line = <$infile> ){
      chomp $line;

      say {$outfile} $line;
    }
  }elsif( $opts{encode} ){
    while( my $line = <$infile> ){
      chomp $line;

      $line =~ s/[\W_]+/ /g;

      say {$outfile} $line;
    }
  }else{
    die 'How did I get here?';
  }
}

sub help{
  pod2usage();
}
sub man{
  pod2usage(1);
}
__END__

=head1 NAME

sample.pl - Using GetOpt::Long and Pod::Usage

=head1 SYNOPSIS

sample.pl [options] [file ...]

 Options:
   --help     -h      brief help message
   --man      -m      full documentation
   --encode   -e      encode text
   --decode   -d      decode text
   --infile   -i      input  filename
   --outfile  -o      output filename

=head1 OPTIONS

=over 8

=item B<--help>

Print a brief help message and exits.

=item B<--man>

Prints the manual page and exits.

=item B<--encode>

Removes any character other than /\w/.

=item B<--decode>

Just reads from one file, and writes to the other.

=item B<--infile>

Input filename. If this is '-' or '&0', then read from STDIN instead.
If you use '&0', you must pass it in with quotes.

=item B<--outfile>

Output filename. If this is '-' or '&1', then write to STDOUT instead.
If this is '&2', then write to STDERR instead.
If you use '&1' or '&2', you must pass it in with quotes.

=back

=head1 DESCRIPTION

B<This program> will read the given input file(s) and do something
useful with the contents thereof.

=cut

echo Hello, this is, some text | perl sample.pl -e
Hello this is some text