chomp $line;
    my $nuline =~ tr/a-zA-Z/n-za-mN-ZA-M/;
[download]

It doesn't work like that. That is, you're expecting:

• tr to act on $line, this is the weakest point, since there's nothing connecting them;
• the transliterated string to be put in $nuline, which also doesn't make since you don't have an assignment to it, and even if you had, then it would assign the return value of tr which is not the transliterated string;

Instead you

• assign to $line;
• apply tr to a freshly created $nuline, which is also undefined. So that, BTW, if you were under warnings as you should, you would have get one.

The solution is to

    my $nuline = $line;
    $nuline =~ tr/a-zA-Z/n-za-mN-ZA-M/;
[download]

which can be shortened to

    (my $nuline = $line) =~ tr/a-zA-Z/n-za-mN-ZA-M/;
[download]

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.