While your problem has already been solved by the comments above, another approach could be to use a hash as a translation table for your file names. This way you would not need to iterate through parallel arrays but have the mapping between the IDI and PLL name stored in one structure: 

#!/usr/bin/perl

use warnings;
use strict;
use diagnostics;

use File::Copy;

# Set up hash with original name and new name with unique ISBN
my %names = (
        'I:\Production\TEST\P001.txt' => 'I:\Production\TEST\ISBN_Text
+.txt',
        'I:\Production\TEST\P002.txt' => 'I:\Production\TEST\ISBN2_Tex
+t.txt'
        ); 

# Walk through hash and copy with new filename
while( my( $IDI_name, $PLL_name ) = each %names ) {
    copy( $IDI_name, $PLL_name );
}

[download]

In reply to Re: Renaming multiple files with unique identifiers by hdb
in thread Renaming multiple files with unique identifiers by reedkm

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