ExtUtils::MakeMaker::Locale - phpMan

NAME
    ExtUtils::MakeMaker::Locale - bundled Encode::Locale

SYNOPSIS
      use Encode::Locale;
      use Encode;

      $string = decode(locale => $bytes);
      $bytes = encode(locale => $string);

      if (-t) {
          binmode(STDIN, ":encoding(console_in)");
          binmode(STDOUT, ":encoding(console_out)");
          binmode(STDERR, ":encoding(console_out)");
      }

      # Processing file names passed in as arguments
      my $uni_filename = decode(locale => $ARGV[0]);
      open(my $fh, "<", encode(locale_fs => $uni_filename))
         || die "Can't open '$uni_filename': $!";
      binmode($fh, ":encoding(locale)");
      ...

DESCRIPTION
    In many applications it's wise to let Perl use Unicode for the strings
    it processes. Most of the interfaces Perl has to the outside world are
    still byte based. Programs therefore need to decode byte strings that
    enter the program from the outside and encode them again on the way out.

    The POSIX locale system is used to specify both the language conventions
    requested by the user and the preferred character set to consume and
    output. The "Encode::Locale" module looks up the charset and encoding
    (called a CODESET in the locale jargon) and arranges for the Encode
    module to know this encoding under the name "locale". It means bytes
    obtained from the environment can be converted to Unicode strings by
    calling "Encode::encode(locale => $bytes)" and converted back again with
    "Encode::decode(locale => $string)".

    Where file systems interfaces pass file names in and out of the program
    we also need care. The trend is for operating systems to use a fixed
    file encoding that don't actually depend on the locale; and this module
    determines the most appropriate encoding for file names. The Encode
    module will know this encoding under the name "locale_fs". For
    traditional Unix systems this will be an alias to the same encoding as
    "locale".

    For programs running in a terminal window (called a "Console" on some
    systems) the "locale" encoding is usually a good choice for what to
    expect as input and output. Some systems allows us to query the encoding
    set for the terminal and "Encode::Locale" will do that if available and
    make these encodings known under the "Encode" aliases "console_in" and
    "console_out". For systems where we can't determine the terminal
    encoding these will be aliased as the same encoding as "locale". The
    advice is to use "console_in" for input known to come from the terminal
    and "console_out" for output to the terminal.

    In addition to arranging for various Encode aliases the following
    functions and variables are provided:

    decode_argv( )
    decode_argv( Encode::FB_CROAK )
        This will decode the command line arguments to perl (the @ARGV
        array) in-place.

        The function will by default replace characters that can't be
        decoded by "\x{FFFD}", the Unicode replacement character.

        Any argument provided is passed as CHECK to underlying
        Encode::decode() call. Pass the value "Encode::FB_CROAK" to have the
        decoding croak if not all the command line arguments can be decoded.
        See "Handling Malformed Data" in Encode for details on other options
        for CHECK.

    env( $uni_key )
    env( $uni_key => $uni_value )
        Interface to get/set environment variables. Returns the current
        value as a Unicode string. The $uni_key and $uni_value arguments are
        expected to be Unicode strings as well. Passing "undef" as
        $uni_value deletes the environment variable named $uni_key.

        The returned value will have the characters that can't be decoded
        replaced by "\x{FFFD}", the Unicode replacement character.

        There is no interface to request alternative CHECK behavior as for
        decode_argv(). If you need that you need to call encode/decode
        yourself. For example:

            my $key = Encode::encode(locale => $uni_key, Encode::FB_CROAK);
            my $uni_value = Encode::decode(locale => $ENV{$key}, Encode::FB_CROAK);

    reinit( )
    reinit( $encoding )
        Reinitialize the encodings from the locale. You want to call this
        function if you changed anything in the environment that might
        influence the locale.

        This function will croak if the determined encoding isn't recognized
        by the Encode module.

        With argument force $ENCODING_... variables to set to the given
        value.

    $ENCODING_LOCALE
        The encoding name determined to be suitable for the current locale.
        Encode know this encoding as "locale".

    $ENCODING_LOCALE_FS
        The encoding name determined to be suitable for file system
        interfaces involving file names. Encode know this encoding as
        "locale_fs".

    $ENCODING_CONSOLE_IN
    $ENCODING_CONSOLE_OUT
        The encodings to be used for reading and writing output to the a
        console. Encode know these encodings as "console_in" and
        "console_out".

NOTES
    This table summarizes the mapping of the encodings set up by the
    "Encode::Locale" module:

      Encode      |         |              |
      Alias       | Windows | Mac OS X     | POSIX
      ------------+---------+--------------+------------
      locale      | ANSI    | nl_langinfo  | nl_langinfo
      locale_fs   | ANSI    | UTF-8        | nl_langinfo
      console_in  | OEM     | nl_langinfo  | nl_langinfo
      console_out | OEM     | nl_langinfo  | nl_langinfo

  Windows
    Windows has basically 2 sets of APIs. A wide API (based on passing
    UTF-16 strings) and a byte based API based a character set called ANSI.
    The regular Perl interfaces to the OS currently only uses the ANSI APIs.
    Unfortunately ANSI is not a single character set.

    The encoding that corresponds to ANSI varies between different editions
    of Windows. For many western editions of Windows ANSI corresponds to
    CP-1252 which is a character set similar to ISO-8859-1. Conceptually the
    ANSI character set is a similar concept to the POSIX locale CODESET so
    this module figures out what the ANSI code page is and make this
    available as $ENCODING_LOCALE and the "locale" Encoding alias.

    Windows systems also operate with another byte based character set. It's
    called the OEM code page. This is the encoding that the Console takes as
    input and output. It's common for the OEM code page to differ from the
    ANSI code page.

  Mac OS X
    On Mac OS X the file system encoding is always UTF-8 while the locale
    can otherwise be set up as normal for POSIX systems.

    File names on Mac OS X will at the OS-level be converted to NFD-form. A
    file created by passing a NFC-filename will come in NFD-form from
    readdir(). See Unicode::Normalize for details of NFD/NFC.

    Actually, Apple does not follow the Unicode NFD standard since not all
    character ranges are decomposed. The claim is that this avoids problems
    with round trip conversions from old Mac text encodings. See
    Encode::UTF8Mac for details.

  POSIX (Linux and other Unixes)
    File systems might vary in what encoding is to be used for filenames.
    Since this module has no way to actually figure out what the is correct
    it goes with the best guess which is to assume filenames are encoding
    according to the current locale. Users are advised to always specify
    UTF-8 as the locale charset.

SEE ALSO
    I18N::Langinfo, Encode, Term::Encoding

AUTHOR
    Copyright 2010 Gisle Aas <gisle AT aas.no>.

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