Re: My UTF-8 text isn't surviving I/O as expected

[choroba]

You have correctly prepared the code to handle UTF-8 in the source code and input and output operations. What's missing is doing the same for the communication with the database.

By default, DBD::SQLite uses a setting which is wrong (see the documentation for details). To fix it, only slight changes are needed:

use DBD::SQLite::Constants ':dbd_sqlite_string_mode';

my $dbh = DBI->connect( "dbi:SQLite:dbname=:memory:", "", "",
          {RaiseError => 1,
           AutoCommit => 1,
           sqlite_string_mode => DBD_SQLITE_STRING_MODE_UNICODE_STRICT
          });

PerlMonks is very old and its <code> sections can't handle Unicode. Either use <pre> instead, or replace unicode characters in the source code by their names:

my $utf8_text1 = "\N{LATIN CAPITAL LETTER A WITH RING ABOVE}ke Lindstr
+\N{LATIN SMALL LETTER O WITH DIAERESIS}m";

BTW, get into the habit of using placeholders to insert values to prevent SQL injection:

my $insert = $dbh->prepare('INSERT INTO names VALUES(?, ?)');
$insert->execute('nm0512537', $utf8_text1);

[ibm1620]

THANK YOU!! That cleared up a lot. I didn't even suspect that the culprit was sqlite.

I still have trouble reading UTF-8 from command line arguments. I assume this is not a Perl issue; any suggestions how to fix?

#!/usr/bin/env perl
use v5.40;
use utf8;
use open qw(:std :encoding(UTF-8));

my $utf8_text1 = shift;
say "A variable set from argument on command line";
show ($utf8_text1);

my $utf8_text2 = 'Åke Lindström;
say "A variable set to UTF8 literal";
show($utf8_text2);

chomp (my $utf8_text3 = <>);
say "A variable set by reading from STDIN";
show($utf8_text3);

sub show($str) {
    say "Binary:      ", join ' ', (unpack "H*", $str) =~ m/../g ;
    say "Text>STDOUT: $str";
}

Output:

$ echo "Åke Lindström" | u 'Åke Lindström'
A variable set from argument on command line
Binary:      c3 85 6b 65 20 4c 69 6e 64 73 74 72 c3 b6 6d
Text>STDOUT: Åke Lindström
A variable set to UTF8 literal
Binary:      c5 6b 65 20 4c 69 6e 64 73 74 72 f6 6d
Text>STDOUT: Åke Lindström
A variable set by reading from STDIN
Binary:      c5 6b 65 20 4c 69 6e 64 73 74 72 f6 6d
Text>STDOUT: Åke Lindström

[choroba]

> reading UTF-8 from command line arguments

Perl Unicode Cookbook: Decode @ARGV as UTF-8