http://www.perlmonks.org?node_id=744914


in reply to RFC: Basic debugging checklist

Check for unprintable characters and identify them by their ASCII codes using ord 
print ":$_:", ord($_), "\n" for (split //, $str)

[download]
That, IMO, makes it hard to spot unexpected unprintable characters because you turn ALL characters into numbers. I often do: 
my $copy = $str;
$str =~ s/([^\x20-\x7E])/sprintf '\x{%02x}', ord $1/eg;
print $str, "\n";

[download]
which leaves all printable ASCII characters as is, and turns all other characters into hex escapes.

In Section Meditations