#!/usr/bin/perl

use warnings;
use strict;

open( my $output, '>', '/tmp/output.txt' )
  or die "Error: Cannot open the file - $!\n";

open( my $input, '<', '/tmp/input.txt' )
  or die "Error: Cannot open the  file - $!\n";

print {$output} while (<$input>);   ## This is were the problem is.

close( $input );
close( $output );

##</code><code>##

syntax error at test.pl line 12, near "} while"
Execution of test.pl aborted due to compilation errors.

##</code><code>##

print $output while (<$input>);

##</code><code>##

GLOB(0x84f3bdc)GLOB(0x84f3bdc)....

##</code><code>##

print {$output} $_ while (<$input>);
or
print $output $_ while (<$input>);

##</code><code>##

#!/usr/bin/perl

use warnings;
use strict;

open( OUTPUT, '>', '/tmp/output.txt' )
  or die "Error: Cannot open the file - $!\n";

open( my $input, '<', '/tmp/input.txt' )
  or die "Error: Cannot open the  file - $!\n";

print OUTPUT while (<$input>);

close( $input );
close( OUTPUT );