#!./perl

use 5.008001;

BEGIN { pop @INC if $INC[-1] eq '.' }

use strict;

use warnings;

use Encode;

use Getopt::Std;

use Carp;

use Encode::Guess;

$Getopt::Std::STANDARD_HELP_VERSION = 1;

my %opt;

getopts( "huSs:", \%opt );

my @suspect_list;

list_valid_suspects() and exit if $opt{S};

@suspect_list = split /:,/, $opt{s} if $opt{s};

HELP_MESSAGE() if $opt{h};

HELP_MESSAGE() unless @ARGV;

do_guess($_) for @ARGV;

sub read_file {

    my $filename = shift;

    local $/;

    open my $fh, '<:raw', $filename or croak "$filename:$!";

    my $content = <$fh>;

    close $fh;

    return $content;

}

sub do_guess {

    my $filename = shift;

    my $data     = read_file($filename);

    my $enc      = guess_encoding( $data, @suspect_list );

    if ( !ref($enc) && $opt{u} ) {

        return 1;

    }

    print "$filename\t";

    if ( ref($enc) ) {

        print $enc->mime_name();

    }

    else {

        print "unknown";

    }

    print "\n";

    return 1;

}

sub list_valid_suspects {

    print join( "\n", Encode->encodings(":all") );

    print "\n";

    return 1;

}

sub HELP_MESSAGE {

    exec 'pod2usage', $0 or die "pod2usage: $!" 

}

__END__

=head1 NAME

encguess - guess character encodings of files

=head1 VERSION

$Id: encguess,v 0.2 2016/08/04 03:15:58 dankogai Exp $

=head1 SYNOPSIS

  encguess [switches] filename...

=head2 SWITCHES

=over 2

=item -h

show this message and exit.

=item -s

specify a list of "suspect encoding types" to test, 

seperated by either C<:> or C<,>

=item -S

output a list of all acceptable encoding types that can be used with

the -s param

=item -u

suppress display of unidentified types

=back

=head2 EXAMPLES:

=over 2

=item *

Guess encoding of a file named C<test.txt>, using only the default

suspect types.

   encguess test.txt

=item *

Guess the encoding type of a file named C<test.txt>, using the suspect

types C<euc-jp,shiftjis,7bit-jis>.

   encguess -s euc-jp,shiftjis,7bit-jis test.txt

   encguess -s euc-jp:shiftjis:7bit-jis test.txt

=item *

Guess the encoding type of several files, do not display results for

unidentified files.

   encguess -us euc-jp,shiftjis,7bit-jis test*.txt

=back

=head1 DESCRIPTION

The encoding identification is done by checking one encoding type at a

time until all but the right type are eliminated. The set of encoding

types to try is defined by the -s parameter and defaults to ascii,

utf8 and UTF-16/32 with BOM. This can be overridden by passing one or

more encoding types via the -s parameter. If you need to pass in

multiple suspect encoding types, use a quoted string with the a space

separating each value.

=head1 SEE ALSO

L<Encode::Guess>, L<Encode::Detect>

=head1 LICENSE AND COPYRIGHT

Copyright 2015 Michael LaGrasta and Dan Kogai.

This program is free software; you can redistribute it and/or modify it

under the terms of the the Artistic License (2.0). You may obtain a

copy of the full license at:

L<http://www.perlfoundation.org/artistic_license_2_0>

=cut