utf8 for require scripts

YarNik has asked for the wisdom of the Perl Monks concerning the following question:

Hello Monks,

In Perl v5.10.1 I did not declare utf8 for require scripts, but in Perl v5.16.3 it is necessary.

What is another solution, do not change a lot of require scripts?

Now my index.pl script looks like this:

#!/usr/bin/perl
use CGI::Carp qw(warningsToBrowser fatalsToBrowser);
use utf8;
use CGI qw/:standard -utf8 -nosticky/;
use open qw/:utf8/;
binmode(STDOUT, ":utf8");
print header(-type => 'text/html',-charset => 'UTF-8');
print "one один\n";
require "index_req.pl";
print @select;

index_req.pl

#!/usr/bin/perl
@select = qw(one один);
1;

output:

one один one????????

if I add utf8 in index_req.pl

#!/usr/bin/perl
use utf8;
@select = qw(one один);
1;

then output is good:

one один oneодин

Comment on utf8 for require scripts

Replies are listed 'Best First'.
Re: utf8 for require scripts by haukex (Archbishop) on Dec 23, 2019 at 13:32 UTC
A bisect confirms the change is due to the fixing of bug RT#96008 in 639dfab: before v5.16.0, use and require were affected by the open pragma. Since your `index_req.pl` is apparently encoded in UTF-8, it does require a `use utf8;` at the top, because that's basically what the utf8 pragma means: "this lexical block is encoded in UTF-8". Sorry, but the best practice here is to put the `use utf8;` pragma at the top of every Perl source file that is encoded in UTF-8, everything else is a hack, or workaround at best.	[reply] [d/l] [select]
Re^2: utf8 for require scripts by YarNik (Sexton) on Dec 23, 2019 at 13:40 UTC
I understand, thanks for the explanation.	[reply]
Re: utf8 for require scripts (updated) by haukex (Archbishop) on Dec 23, 2019 at 11:25 UTC
Which of the four instances of `utf8` in your sample are you referring to? And could you show some example code that reproduces the problem? Short, Self-Contained, Correct Example Update: Thank you for adding some sample code, but see How do I change/delete my post? - please mark your edits as such. Also, did you mean `один` or `один`? On PerlMonks, if you meant the latter, unfortunately it's required to use `<pre>` instead of `<code>` tags, which means that HTML/PM special characters like `<`, `>`, `&`, `[`, and `]` need to be escaped too (respectively, `<`, `>`, `&`, `[`, and `]`).	[reply] [d/l] [select]
Re^2: utf8 for require scripts (updated) by YarNik (Sexton) on Dec 23, 2019 at 12:38 UTC
I changed the message, but the block with the code changes Unicode to utf8 by default, so I showed how it looks in the original. Upd. Thank you, I changed it with pre	[reply]