in reply to Re^2: Invalid argument
in thread Invalid argument

Whoops -- didn't read that far :-/

It's because you're not passing @_.

You could fix this with:

handlefix(@_);
but it's really better practice to chomp the variables on input, and assign them to actual variable names, leaving @_ to its better purpose of the default argument list.

s''(q.S:$/9=(T1';s;(..)(..);$..=substr+crypt($1,$2),2,3;eg;print$..$/