When interpolating a variable in quotes, Perl cannot always tell what the variable is. A variable named $_new is perfectly legal. Wrap the actual variable name in curly braces '{}' to let Perl know what variable you are referring to.

print DESTINATION "old: ${_}new: $line\n";
[download]

Otherwise, you could wind up with problems like this:

my $a = 1;
my $ab = 1;
my $abc = 1;
my $abcd = 1;

# what do we want to print?
print "$abcd";
[download]

Cheers,
Ovid

Join the Perlmonks Setiathome Group or just click on the the link and check out our stats.