NAME
    DjVu::Detect - Detect DjVu files.

SYNOPSIS
     use DjVu::Detect qw(detect_djvu_file detect_djvu_chunk);

     my $has_djvu_chunk = detect_djvu_chunk($file, $chunk_name);
     my $is_djvu = detect_djvu_file($file);

DESCRIPTION
    This Perl module detect DjVu files through magic string and detect if
    DjVu file has chunk type.

    List of supported files: djvu

SUBROUTINES
  "detect_djvu_chunk"
     my $has_djvu_chunk = detect_djvu_chunk($file, $chunk_name);

    Detect if DjVu file contain DjVu chunk.

    Returns 1/0.

  "detect_djvu_file"
     my $is_djvu = detect_djvu_file($file);

    Detect if file is DjVu file by magic string of IFF and first 'FORM'
    chunk.

    Returns 1/0.

ERRORS
     detect_djvu_chunk():
             Program 'djvudump' doesn't exists.

     detect_dwg_file():
             Cannot close file '%s'.
             Cannot open file '%s'.

EXAMPLE1
     use strict;
     use warnings;

     use DjVu::Detect qw(detect_djvu_file);
     use File::Temp qw(tempfile);
     use IO::Barf qw(barf);
     use MIME::Base64;

     # Data in base64.
     my $data = <<'END';
     QVQmVEZPUk0=
     END

     # Temp file.
     my (undef, $temp_file) = tempfile();

     # Save data to file.
     barf($temp_file, decode_base64($data));

     # Check file.
     my $is_djvu = detect_djvu_file($temp_file);

     # Print out.
     if ($is_djvu) {
             print "File '$temp_file' is DjVu file.\n";
     } else {
             print "File '$temp_file' isn't DjVu file.\n";
     }

     # Output like:
     # File '%s' isn't DjVu file.

EXAMPLE2
     use strict;
     use warnings;

     use DjVu::Detect qw(detect_djvu_file);

     # Arguments.
     if (@ARGV < 1) {
             print STDERR "Usage: $0 file\n";
             exit 1;
     }
     my $file = $ARGV[0];

     # Check DjVu file.
     my $is_djvu = detect_djvu_file($file);

     # Print out.
     if ($is_djvu) {
             print "File '$file' is DjVu file.\n";
     } else {
             print "File '$file' isn't Djvu file.\n";
     }

     # Output:
     # Usage: __SCRIPT__ file

DEPENDENCIES
    Error::Pure, Exporter, File::Which.

SEE ALSO
    File::Find::Rule::DjVu
        Common rules for searching DjVu files.

REPOSITORY
    <https://github.com/michal-josef-spacek/DjVu-Detect>

TEST FILES
    Test file 11a7ffc0-c61e-11e6-ac1c-001018b5eb5c.djvu is generated from
    scanned book edition from
    <http://www.digitalniknihovna.cz/mzk/view/uuid:814e66a0-b6df-11e6-88f6-0
    05056827e52?page=uuid:11a7ffc0-c61e-11e6-ac1c-001018b5eb5c>

AUTHOR
    Michal Josef Špaček <mailto:skim@cpan.org>

    <http://skim.cz>

LICENSE AND COPYRIGHT
    © 2021 Michal Josef Špaček

    BSD 2-Clause License

VERSION
    0.04