package RDW;

use strict;
use warnings;
use Carp;
require Exporter;

our( $VERSION, @ISA, @EXPORT );

$VERSION = "0.1";

@ISA = qw(Exporter);
sub rdw_open {
    my $self;
    my $class = shift;
    my $file  = shift;
    $file =~ s/^/</ if ( $file =~ m!^/?\w! );

    open( my $fh, $file, @_ ) or return undef;
    $self->{FILE}     = $fh;
         #$self->{FILENAME} = $filename;
    bless $self, $class;
    return $self;
}

sub rdw_close {
    my $self = shift;
    my $fh   = $self->{FILE};
    close($fh) or return undef;
    return 1;
}
sub read_rdw {
    my $self = shift;
    my $fh   = $self->{FILE};
    my ( $rec_len, $rc, $len, $ret_val );

    # Read record length
    $rc = sysread( $fh, $rec_len, 2 );
    ( !defined($rc) ) && die "ERROR: rdw_read() failed read.\n";

    $len = unpack( "S", $rec_len );

    # Read record data
    if ( !defined($len) ) {
        return undef;
    }
    $rc = sysread( $fh, $ret_val, $len );
    ( !defined($rc) ) && die "ERROR: rdw_read() failed read.\n";

    # Return record data
    return $ret_val;
}

sub write_rdw {
    my $self = shift;
    my $fh   = $self->{FILE};
    my $line = join "", @_;
    print( $fh pack( "S", length($line) ), $line )
      or croak "Can't write record to file: $!";
}
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