http://qs1969.pair.com?node_id=830633


in reply to Re: Why does perl's internal utf8 seem to allow single-byte latin1?
in thread Why does perl's internal utf8 seem to allow single-byte latin1?

The output of the script is in the original post:
Ein <#c3><#96>konomisches Modell Ein <#d6>konomisches Modell 1 Ein <#d6>konomisches Modell 1
I expected to see <#c3><#96> in all three cases. The actual confusion on the test script turns out to be a bug in the "print_chrcodes" function. I either should have used Devel::Peek, or ensured the function used "use bytes":
sub print_chrcodes { my $str = shift; my $ret; use bytes; #<<<<<<<<<here foreach my $ascval (unpack("C*", $str)) { if($ascval == 13) { $ret .= '<cr>'; next; } if($ascval == 10) { $ret .= '<nl>'; next; } if($ascval < 128) { $ret .= chr($ascval); next; } $ret .= sprintf ("<#%x>",$ascval) if($ascval >= 128); } return $ret; }
What I was diagnosing was a situation where Unicode did not cleanly go through Storable::nfreeze, a database, then Storable::thaw :
$hash->{TITLE}="f\xc3\xa4ce=\xe2\x98\xbb"; print "TITLE=$hash->{TITLE}\n"; my $nfreeze = Storable::nfreeze($hash); my $obj = Storable::thaw($nfreeze); print '${^UNICODE}='.${^UNICODE}."\n"; print "TITLE=$obj->{TITLE}\n";
That eventually resolved itself. The setting of PERL_UNICODE=SAD vs. PERL_UNICODE=0 was masking the true problem, as it allowed certain sequences perl thought of as latin1 to be seen on the terminal as their equivalent utf-8 character (in my test case, black smiling face ☻).

So in the end with: use encoding "utf-8-strict"; added to the script, and PERL_UNICODE=SAD, and proper terminal settings, and Apache Accept-Charset, and SET CLIENT-ENCODING UTF8 I'm round tripping Uncode through the entire Browser->Apache->Perl->Database->Perl->Apache->Browser System.

Thanks for the help.