#!/usr/bin/perl

# rename.pl - given two files of MARC records, extract the identifiers in one and rename the identifiers in the other

# Eric Lease Morgan <eric_morgan@infomotions.com>
# April 5, 2016 - first cut


# require
use MARC::Batch;
use strict;

# sanity check
my $original = $ARGV[ 0 ];
my $new      = $ARGV[ 1 ];
if ( ! $new or ! $original ) {

	print "Usage: $0 <original> <newfile>\n";
	exit;
	
}

# initialize
my %identifiers = ();
binmode(STDOUT, ":utf8");

# process each record in the new file storing the result in a hash
my $batch = MARC::Batch->new( 'USMARC', $new );
while ( my $record = $batch->next ) {
		
	# local identifier
	$identifiers{ $record->field( '001' )->as_string }++
		
}

# process each record in the original file
my $batch = MARC::Batch->new( 'USMARC', $original );
while ( my $record = $batch->next ) {

	# get the identifier
	my $identifier = $record->field( '001' )->as_string;
	
	# check to see if the current identifier is in the previously created list	
	if ( $identifiers{ $identifier } ) {
	
		# munge the identifier
		$record->field( '001' )->update( 'x-' . $identifier );
		
	}
	
	# output
	print $record->as_usmarc;
	
}


# done
exit;