debase/debase at master · joshhead/debase · GitHub

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#!/usr/bin/env perl
use warnings;
use strict;
use MIME::Base64 qw(encode_base64);
use Getopt::Std;
$Getopt::Std::STANDARD_HELP_VERSION = "true";
$main::VERSION = "0.2";

sub HELP_MESSAGE {
  my $fh = shift || \*STDERR;
  print $fh "Usage: debase input.file\n";
}

# I plan to extend this later so that it will
# transparently use File::MimeInfo or the mimetype command
# depending on what is available
sub getMimeType {
  my $filename = shift;
  return undef if ($filename eq "");
  my $mimetype = `mimetype -b $filename`;
  chomp $mimetype;
  return undef if ($mimetype eq "");
  return $mimetype;
}

sub runTests {
  print "Running unit tests.\n";
  getMimeType("/usr/bin/env") eq 'application/x-executable' || die ("/usr/bin/env should have type application/x-executable\n");
  !defined getMimeType("") || die ("Empty filename should have failed\n");
  !defined getMimeType("/home/unlikelyusername/nosuchfile") || die ("Non-existant file should have failed.\n");
  print "All tests passed.\n";
}

sub getMimeChunker {
  my $filename = shift;
  my $chunkSize = shift || 30;
  my $buf;
  open(my $fh, "<", $filename) or return undef;
  return sub {
    if (read($fh, $buf, $chunkSize)) {
      my $section = encode_base64($buf);
      chomp $section;
      return $section;
    } else {
      close($fh);
      return undef;
    }
  }
}

# Chunker should be a code reference that returns strings when called
# until there are no more chunks, then returns a false value
sub printFile {
  my $mimeType = shift;
  my $chunker = shift;
  print qq(<!DOCTYPE html>\n);
  print qq(<html>\n);
  print qq(<body>\n);
  print qq(<p>Encoded Data Follows. To automatically decode, please enable JavaScript.<br />\n);
  print qq(MIME type: $mimeType</p>\n);
  print qq(<pre id="encoded_data">\n);
  while (my $chunk = $chunker->()) {
    print qq($chunk\n);
  }
  print qq(</pre>\n);
  print qq(<script type="text/javascript">\n);
  print qq(location.href="data:$mimeType;base64,"+\n);
  print qq(document.getElementById("encoded_data").innerHTML;\n);
  print qq(</script>\n);
  print qq(</body>\n);
  print qq(</html>\n);
}

my %opts;
getopts('t', \%opts);
if (exists $opts{t}) {
  runTests();
  exit(0);
}
if (!defined $ARGV[0]) {
  HELP_MESSAGE();
  exit(1);
}

my $mimeType = getMimeType($ARGV[0]) or die(qq(Could not determine type of file "$ARGV[0]"));
my $chunker = getMimeChunker($ARGV[0]) or die(qq(Could not open file "$ARGV[0]"));
printFile($mimeType, $chunker);