Using your original code, how about this modification?

if (uc($ARGV[1]) eq 'E') { 
    $_ = $ARGV[0];
    tr/a-zA-Z/epstiwknuvgclrybxhmdofzqajEPSTIWKNUVGCLRYBXHMDOFZQAJ/;
}
    
else {
    $_ = $ARGV[0];
    tr/a-zA-Z/ypltavkrezgmshubxncdijfqowYPLTAVKREZGMSHUBXNCDIJFQOW/;
}

print;
[download]

This can translate to and from Al Bhed. The first argument is what you want translated, the second is how you want it translated (A for Al Bhed, E for English)

This

perl albhed.pl "Translate Me" A

results in "Dnyhcmyda Sa".

And

perl albhed.pl "Dnyhcmyda Sa" E

results in "Translate Me".

---

Sarah
Reach out and GREP someone. -- Seen on a license plate