# during intialization:
    $encoding = "utf8"; # or "encoding(cp1252)" or whatever
    binmode STDOUT, $encoding;  # (if this is appropriate)
    binmode STDIN, $encoding;
# ...

# then make all open statements look like this:
#   open( INHANDLE, "<$encoding", $ifilename )
#   open( OUTHANDLE, ">$encoding", $ofilename )