I'm assuming that the reason you asked that question here is because you may be working with that data in a Perl script - so I'm going to answer with a Perl snippet (the correct solution, as several people have already pointed out, is still to let the DB do it):

my @col_names = qw/first_name middle_name last_name address phone_numb
+er/;
my $total_len = join '+', map { "char_length($_)" } @col_names;
my $sql = "SELECT $total_len AS 'Row Length' FROM table ORDER BY $tota
+l_len";
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