Current File : //usr/share/doc/perl-utf8-all/README.mkdn

# NAME

utf8::all - turn on Unicode - all of it

# VERSION

version 0.024

# SYNOPSIS

    use utf8::all;                      # Turn on UTF-8, all of it.

    open my $in, '<', 'contains-utf8';  # UTF-8 already turned on here
    print length 'føø bār';             # 7 UTF-8 characters
    my $utf8_arg = shift @ARGV;         # @ARGV is UTF-8 too (only for main)

# DESCRIPTION

The `use utf8` pragma tells the Perl parser to allow UTF-8 in the
program text in the current lexical scope. This also means that you
can now use literal Unicode characters as part of strings, variable
names, and regular expressions.

`utf8::all` goes further:

- [`charnames`](https://metacpan.org/pod/charnames) are imported so `\N{...}` sequences can be
used to compile Unicode characters based on names.
- On Perl `v5.11.0` or higher, the `use feature 'unicode_strings'` is
enabled.
- `use feature fc` and `use feature unicode_eval` are enabled on Perl
`5.16.0` and higher.
- Filehandles are opened with UTF-8 encoding turned on by default
(including `STDIN`, `STDOUT`, and `STDERR` when `utf8::all` is
used from the `main` package). Meaning that they automatically
convert UTF-8 octets to characters and vice versa. If you _don't_
want UTF-8 for a particular filehandle, you'll have to set `binmode
$filehandle`.
- `@ARGV` gets converted from UTF-8 octets to Unicode characters (when
`utf8::all` is used from the `main` package). This is similar to the
behaviour of the `-CA` perl command-line switch (see [perlrun](https://metacpan.org/pod/perlrun)).
- `readdir`, `readlink`, `readpipe` (including the `qx//` and
backtick operators), and [`glob`](https://metacpan.org/pod/perlfunc#glob) (including the `<>` operator) now all work with and return Unicode characters
instead of (UTF-8) octets (again only when `utf8::all` is used from
the `main` package).

## Lexical Scope

The pragma is lexically-scoped, so you can do the following if you had
some reason to:

    {
        use utf8::all;
        open my $out, '>', 'outfile';
        my $utf8_str = 'føø bār';
        print length $utf8_str, "\n"; # 7
        print $out $utf8_str;         # out as utf8
    }
    open my $in, '<', 'outfile';      # in as raw
    my $text = do { local $/; <$in>};
    print length $text, "\n";         # 10, not 7!

Instead of lexical scoping, you can also use `no utf8::all` to turn
off the effects.

Note that the effect on `@ARGV` and the `STDIN`, `STDOUT`, and
`STDERR` file handles is always global and can not be undone!

## Enabling/Disabling Global Features

As described above, the default behaviour of `utf8::all` is to
convert `@ARGV` and to open the `STDIN`, `STDOUT`, and `STDERR`
file handles with UTF-8 encoding, and override the `readlink` and
`readdir` functions and `glob` operators when `utf8::all` is used
from the `main` package.

If you want to disable these features even when `utf8::all` is used
from the `main` package, add the option `NO-GLOBAL` (or
`LEXICAL-ONLY`) to the use line. E.g.:

    use utf8::all 'NO-GLOBAL';

If on the other hand you want to enable these global effects even when
`utf8::all` was used from another package than `main`, use the
option `GLOBAL` on the use line:

    use utf8::all 'GLOBAL';

## UTF-8 Errors

`utf8::all` will handle invalid code points (i.e., utf-8 that does
not map to a valid unicode "character"), as a fatal error.

For `glob`, `readdir`, and `readlink`, one can change this
behaviour by setting the attribute ["$utf8::all::UTF8\_CHECK"](#utf8-all-utf8_check).

# ATTRIBUTES

## $utf8::all::UTF8\_CHECK

By default `utf8::all` marks decoding errors as fatal (default value
for this setting is `Encode::FB_CROAK`). If you want, you can change this by
setting `$utf8::all::UTF8_CHECK`. The value `Encode::FB_WARN` reports
the encoding errors as warnings, and `Encode::FB_DEFAULT` will completely
ignore them. Please see [Encode](https://metacpan.org/pod/Encode) for details. Note: `Encode::LEAVE_SRC` is
_always_ enforced.

Important: Only controls the handling of decoding errors in `glob`,
`readdir`, and `readlink`.

# INTERACTION WITH AUTODIE

If you use [autodie](https://metacpan.org/pod/autodie), which is a great idea, you need to use at least
version **2.12**, released on [June 26,
2012](https://metacpan.org/source/PJF/autodie-2.12/Changes#L3).
Otherwise, autodie obliterates the IO layers set by the [open](https://metacpan.org/pod/open)
pragma. See [RT
\#54777](https://rt.cpan.org/Ticket/Display.html?id=54777) and [GH
\#7](https://github.com/doherty/utf8-all/issues/7).

# BUGS

Please report any bugs or feature requests on the bugtracker
[website](https://github.com/doherty/utf8-all/issues).

When submitting a bug or request, please include a test-file or a
patch to an existing test-file that illustrates the bug or desired
feature.

# COMPATIBILITY

The filesystems of Dos, Windows, and OS/2 do not (fully) support
UTF-8. The `readlink` and `readdir` functions and `glob` operators
will therefore not be replaced on these systems.

# SEE ALSO

- [File::Find::utf8](https://metacpan.org/pod/File::Find::utf8) for fully utf-8 aware File::Find functions.
- [Cwd::utf8](https://metacpan.org/pod/Cwd::utf8) for fully utf-8 aware Cwd functions.

# AUTHORS

- Michael Schwern <mschwern@cpan.org>
- Mike Doherty <doherty@cpan.org>
- Hayo Baan <info@hayobaan.com>

# COPYRIGHT AND LICENSE

This software is copyright (c) 2009 by Michael Schwern <mschwern@cpan.org>; he originated it.

This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.