NAME

KOI8U - Source code filter to escape KOI8-U script

Install and Usage

There are two steps there:

  • You'll have to download KOI8U.pm and Ekoi8u.pm and put it in your perl lib directory.

  • You'll need to write "use KOI8U;" at head of the script.

SYNOPSIS

  use KOI8U;
  use KOI8U ver.sion;             --- require minimum version
  use KOI8U ver.sion.0;           --- expects version (match or die)

  # "no KOI8U;" not supported

  or

  $ perl KOI8U.pm KOI8-U_script.pl > Escaped_script.pl.e

  then

  $ perl Escaped_script.pl.e

  KOI8-U_script.pl  --- script written in KOI8-U
  Escaped_script.pl.e --- escaped script

  subroutines:
    KOI8U::eval(...);
  dummy functions:
    utf8::upgrade(...);
    utf8::downgrade(...);
    utf8::encode(...);
    utf8::decode(...);
    utf8::is_utf8(...);
    utf8::valid(...);
    bytes::chr(...);
    bytes::index(...);
    bytes::length(...);
    bytes::ord(...);
    bytes::rindex(...);
    bytes::substr(...);

ABSTRACT

KOI8U software is "middleware" between perl interpreter and your Perl script written in KOI8-U.

Perl is optimized for problems which are about 90% working with text and about 10% everything else. Even if this "text" doesn't contain KOI8-U, Perl3 or later can treat KOI8-U as binary data.

By "use KOI8U;", it automatically interpret your script as KOI8-U. The various functions of perl including a regular expression can treat KOI8-U now. The function length treats length per byte. This software does not use UTF8 flag.

Yet Another Future Of

JPerl is very useful software. -- Oops, note, this "JPerl" means "Japanized Perl" or "Japanese Perl". Therefore, it is unrelated to JPerl of the following.

 JPerl is an implementation of Perl written in Java.
 http://www.javainc.com/projects/jperl/
 
 jPerl - Perl on the JVM
 http://www.dzone.com/links/175948.html
 
 Jamie's PERL scripts for bioinformatics
 http://code.google.com/p/jperl/
 
 jperl (Jonathan Perl)
 https://github.com/jperl

Now, the last version of JPerl is 5.005_04 and is not maintained now.

Japanization modifier WATANABE Hirofumi said,

  "Because WATANABE am tired I give over maintaing JPerl."

at Slide #15: "The future of JPerl" of

ftp://ftp.oreilly.co.jp/pcjp98/watanabe/jperlconf.ppt

in The Perl Confernce Japan 1998.

When I heard it, I thought that someone excluding me would maintain JPerl. And I slept every night hanging a sock. Night and day, I kept having hope. After 10 years, I noticed that white beard exists in the sock :-)

This software is a source code filter to escape Perl script encoded by KOI8-U given from STDIN or command line parameter. The character code is never converted by escaping the script. Neither the value of the character nor the length of the character string change even if it escapes.

I learned the following things from the successful software.

  • Upper Compatibility like Perl4 to Perl5

  • Maximum Portability like jcode.pl

  • Remains One Language Handling Raw KOI8-U, Doesn't Use UTF8 flag like JPerl

  • Remains One Interpreter like Encode module

  • Code Set Independent like Ruby

  • Monolithic Script like cpanminus

  • There's more than one way to do it like Perl itself

I am excited about this software and Perl's future --- I hope you are too.

JRE: JPerl Runtime Environment

  +---------------------------------------+
  |        JPerl Application Script       | Your Script
  +---------------------------------------+
  |  Source Code Filter, Runtime Routine  | ex. KOI8U.pm, Ekoi8u.pm
  +---------------------------------------+
  |          PVM 5.00503 or later         | ex. perl 5.00503
  +---------------------------------------+

A Perl Virtual Machine (PVM) enables a set of computer software programs and data structures to use a virtual machine model for the execution of other computer programs and scripts. The model used by a PVM accepts a form of computer intermediate language commonly referred to as Perl byteorientedcode. This language conceptually represents the instruction set of a byte-oriented, capability architecture.

Basic Idea of Source Code Filter

I discovered this mail again recently.

[Tokyo.pm] jus Benkyoukai

http://mail.pm.org/pipermail/tokyo-pm/1999-September/001854.html

save as: SJIS.pm

  package SJIS;
  use Filter::Util::Call;
  sub multibyte_filter {
      my $status;
      if (($status = filter_read()) > 0 ) {
          s/([\x81-\x9f\xe0-\xef])([\x40-\x7e\x80-\xfc])/
              sprintf("\\x%02x\\x%02x",ord($1),ord($2))
          /eg;
      }
      $status;
  }
  sub import {
      filter_add(\&multibyte_filter);
  }
  1;

I am glad that I could confirm my idea is not so wrong.

Command-line Wildcard Expansion on DOS-like Systems

The default command shells on DOS-like systems (COMMAND.COM or cmd.exe or Win95Cmd.exe) do not expand wildcard arguments supplied to programs. Instead, import of Ekoi8u.pm works well.

   in Ekoi8u.pm
   #
   # @ARGV wildcard globbing
   #
   sub import {

       if ($^O =~ /\A (?: MSWin32 | NetWare | symbian | dos ) \z/oxms) {
           my @argv = ();
           for (@ARGV) {

               # has space
               if (/\A (?:$q_char)*? [ ] /oxms) {
                   if (my @glob = Ekoi8u::glob(qq{"$_"})) {
                       push @argv, @glob;
                   }
                   else {
                       push @argv, $_;
                   }
               }

               # has wildcard metachar
               elsif (/\A (?:$q_char)*? [*?] /oxms) {
                   if (my @glob = Ekoi8u::glob($_)) {
                       push @argv, @glob;
                   }
                   else {
                       push @argv, $_;
                   }
               }

               # no wildcard globbing
               else {
                   push @argv, $_;
               }
           }
           @ARGV = @argv;
       }
   }

Software Composition

   KOI8U.pm               --- source code filter to escape KOI8-U
   Ekoi8u.pm              --- run-time routines for KOI8U.pm

Upper Compatibility by Escaping

This software adds the function by 'Escaping' it always, and nothing of the past is broken. Therefore, 'Possible job' never becomes 'Impossible job'. This approach is effective in the field where the retreat is never permitted. It means incompatible upgrade of Perl should be rewound.

Escaping Your Script (You do)

You need write 'use KOI8U;' in your script.

  ---------------------
  You do
  ---------------------
  use KOI8U;
  ---------------------

Calling 'Ekoi8u::ignorecase()' (KOI8U software provides)

KOI8U software applies calling 'Ekoi8u::ignorecase()' instead of /i modifier.

  --------------------------------------------------------------------------------
  Before                  After
  --------------------------------------------------------------------------------
  m/...$var.../i          m/...@{[Ekoi8u::ignorecase($var)]}.../
  --------------------------------------------------------------------------------

Escaping Character Classes (Ekoi8u.pm provides)

The character classes are redefined as follows to backward compatibility.

  ---------------------------------------------------------------
  Before        After
  ---------------------------------------------------------------
   .            ${Ekoi8u::dot}
                ${Ekoi8u::dot_s}    (/s modifier)
  \d            [0-9]              (universally)
  \s            \s
  \w            [0-9A-Z_a-z]       (universally)
  \D            ${Ekoi8u::eD}
  \S            ${Ekoi8u::eS}
  \W            ${Ekoi8u::eW}
  \h            [\x09\x20]
  \v            [\x0A\x0B\x0C\x0D]
  \H            ${Ekoi8u::eH}
  \V            ${Ekoi8u::eV}
  \C            [\x00-\xFF]
  \X            X                  (so, just 'X')
  \R            ${Ekoi8u::eR}
  \N            ${Ekoi8u::eN}
  ---------------------------------------------------------------

Also POSIX-style character classes.

  ---------------------------------------------------------------
  Before        After
  ---------------------------------------------------------------
  [:alnum:]     [\x30-\x39\x41-\x5A\x61-\x7A]
  [:alpha:]     [\x41-\x5A\x61-\x7A]
  [:ascii:]     [\x00-\x7F]
  [:blank:]     [\x09\x20]
  [:cntrl:]     [\x00-\x1F\x7F]
  [:digit:]     [\x30-\x39]
  [:graph:]     [\x21-\x7F]
  [:lower:]     [\x61-\x7A]
                [\x41-\x5A\x61-\x7A]     (/i modifier)
  [:print:]     [\x20-\x7F]
  [:punct:]     [\x21-\x2F\x3A-\x3F\x40\x5B-\x5F\x60\x7B-\x7E]
  [:space:]     [\s\x0B]
  [:upper:]     [\x41-\x5A]
                [\x41-\x5A\x61-\x7A]     (/i modifier)
  [:word:]      [\x30-\x39\x41-\x5A\x5F\x61-\x7A]
  [:xdigit:]    [\x30-\x39\x41-\x46\x61-\x66]
  [:^alnum:]    ${Ekoi8u::not_alnum}
  [:^alpha:]    ${Ekoi8u::not_alpha}
  [:^ascii:]    ${Ekoi8u::not_ascii}
  [:^blank:]    ${Ekoi8u::not_blank}
  [:^cntrl:]    ${Ekoi8u::not_cntrl}
  [:^digit:]    ${Ekoi8u::not_digit}
  [:^graph:]    ${Ekoi8u::not_graph}
  [:^lower:]    ${Ekoi8u::not_lower}
                ${Ekoi8u::not_lower_i}    (/i modifier)
  [:^print:]    ${Ekoi8u::not_print}
  [:^punct:]    ${Ekoi8u::not_punct}
  [:^space:]    ${Ekoi8u::not_space}
  [:^upper:]    ${Ekoi8u::not_upper}
                ${Ekoi8u::not_upper_i}    (/i modifier)
  [:^word:]     ${Ekoi8u::not_word}
  [:^xdigit:]   ${Ekoi8u::not_xdigit}
  ---------------------------------------------------------------

\b and \B are redefined as follows to backward compatibility.

  ---------------------------------------------------------------
  Before      After
  ---------------------------------------------------------------
  \b          ${Ekoi8u::eb}
  \B          ${Ekoi8u::eB}
  ---------------------------------------------------------------

Definitions in Ekoi8u.pm.

  ---------------------------------------------------------------------------------------------------------------------------------------------------------
  After                    Definition
  ---------------------------------------------------------------------------------------------------------------------------------------------------------
  ${Ekoi8u::dot}            qr{(?>[^\x0A])};
  ${Ekoi8u::dot_s}          qr{(?>[\x00-\xFF])};
  ${Ekoi8u::eD}             qr{(?>[^0-9])};
  ${Ekoi8u::eS}             qr{(?>[^\s])};
  ${Ekoi8u::eW}             qr{(?>[^0-9A-Z_a-z])};
  ${Ekoi8u::eH}             qr{(?>[^\x09\x20])};
  ${Ekoi8u::eV}             qr{(?>[^\x0A\x0B\x0C\x0D])};
  ${Ekoi8u::eR}             qr{(?>\x0D\x0A|[\x0A\x0D])};
  ${Ekoi8u::eN}             qr{(?>[^\x0A])};
  ${Ekoi8u::not_alnum}      qr{(?>[^\x30-\x39\x41-\x5A\x61-\x7A])};
  ${Ekoi8u::not_alpha}      qr{(?>[^\x41-\x5A\x61-\x7A])};
  ${Ekoi8u::not_ascii}      qr{(?>[^\x00-\x7F])};
  ${Ekoi8u::not_blank}      qr{(?>[^\x09\x20])};
  ${Ekoi8u::not_cntrl}      qr{(?>[^\x00-\x1F\x7F])};
  ${Ekoi8u::not_digit}      qr{(?>[^\x30-\x39])};
  ${Ekoi8u::not_graph}      qr{(?>[^\x21-\x7F])};
  ${Ekoi8u::not_lower}      qr{(?>[^\x61-\x7A])};
  ${Ekoi8u::not_lower_i}    qr{(?>[^\x41-\x5A\x61-\x7A])}; # Perl 5.16 compatible
# ${Ekoi8u::not_lower_i}    qr{(?>[\x00-\xFF])};                   # older Perl compatible
  ${Ekoi8u::not_print}      qr{(?>[^\x20-\x7F])};
  ${Ekoi8u::not_punct}      qr{(?>[^\x21-\x2F\x3A-\x3F\x40\x5B-\x5F\x60\x7B-\x7E])};
  ${Ekoi8u::not_space}      qr{(?>[^\s\x0B])};
  ${Ekoi8u::not_upper}      qr{(?>[^\x41-\x5A])};
  ${Ekoi8u::not_upper_i}    qr{(?>[^\x41-\x5A\x61-\x7A])}; # Perl 5.16 compatible
# ${Ekoi8u::not_upper_i}    qr{(?>[\x00-\xFF])};                   # older Perl compatible
  ${Ekoi8u::not_word}       qr{(?>[^\x30-\x39\x41-\x5A\x5F\x61-\x7A])};
  ${Ekoi8u::not_xdigit}     qr{(?>[^\x30-\x39\x41-\x46\x61-\x66])};
  
  # This solution is not perfect. I beg better solution from you who are reading this.
  ${Ekoi8u::eb}             qr{(?:\A(?=[0-9A-Z_a-z])|(?<=[\x00-\x2F\x40\x5B-\x5E\x60\x7B-\xFF])(?=[0-9A-Z_a-z])|(?<=[0-9A-Z_a-z])(?=[\x00-\x2F\x40\x5B-\x5E\x60\x7B-\xFF]|\z))};
  ${Ekoi8u::eB}             qr{(?:(?<=[0-9A-Z_a-z])(?=[0-9A-Z_a-z])|(?<=[\x00-\x2F\x40\x5B-\x5E\x60\x7B-\xFF])(?=[\x00-\x2F\x40\x5B-\x5E\x60\x7B-\xFF]))};
  ---------------------------------------------------------------------------------------------------------------------------------------------------------

Un-Escaping \ of \b{}, \B{}, \N{}, \p{}, \P{}, and \X (KOI8U software provides)

KOI8U software removes '\' at head of alphanumeric regexp metasymbols \b{}, \B{}, \N{}, \p{}, \P{} and \X. By this method, you can avoid the trap of the abstraction.

See also, Deprecate literal unescaped "{" in regexes. http://perl5.git.perl.org/perl.git/commit/2a53d3314d380af5ab5283758219417c6dfa36e9

  ------------------------------------
  Before           After
  ------------------------------------
  \b{...}          b\{...}
  \B{...}          B\{...}
  \N{CHARNAME}     N\{CHARNAME}
  \p{L}            p\{L}
  \p{^L}           p\{^L}
  \p{\^L}          p\{\^L}
  \pL              pL
  \P{L}            P\{L}
  \P{^L}           P\{^L}
  \P{\^L}          P\{\^L}
  \PL              PL
  \X               X
  ------------------------------------

Escaping Built-in Functions (KOI8U software provides)

Insert 'Ekoi8u::' at head of function name. Ekoi8u.pm provides your script Ekoi8u::* subroutines.

  -------------------------------------------
  Before      After            Works as
  -------------------------------------------
  lc          Ekoi8u::lc        Character
  lcfirst     Ekoi8u::lcfirst   Character
  uc          Ekoi8u::uc        Character
  ucfirst     Ekoi8u::ucfirst   Character
  fc          Ekoi8u::fc        Character
  chr         Ekoi8u::chr       Character
  glob        Ekoi8u::glob      Character
  -------------------------------------------

  ------------------------------------------------------------------------------------------------------------------------
  Before                   After
  ------------------------------------------------------------------------------------------------------------------------
  use Perl::Module;        BEGIN { require 'Perl/Module.pm'; Perl::Module->import() if Perl::Module->can('import'); }
  use Perl::Module @list;  BEGIN { require 'Perl/Module.pm'; Perl::Module->import(@list) if Perl::Module->can('import'); }
  use Perl::Module ();     BEGIN { require 'Perl/Module.pm'; }
  no Perl::Module;         BEGIN { require 'Perl/Module.pm'; Perl::Module->unimport() if Perl::Module->can('unimport'); }
  no Perl::Module @list;   BEGIN { require 'Perl/Module.pm'; Perl::Module->unimport(@list) if Perl::Module->can('unimport'); }
  no Perl::Module ();      BEGIN { require 'Perl/Module.pm'; }
  ------------------------------------------------------------------------------------------------------------------------

Yada Yada Operator (KOI8U software provides)

  The yada yada operator (noted ...) is a placeholder for code. Perl parses it
  without error, but when you try to execute a yada yada, it throws an exception
  with the text Unimplemented:

  sub unimplemented { ... }
  eval { unimplemented() };
  if ( $@ eq 'Unimplemented' ) {
      print "I found the yada yada!\n";
  }

  You can only use the yada yada to stand in for a complete statement. These
  examples of the yada yada work:

  { ... }
  sub foo { ... }
  ...;
  eval { ... };
  sub foo {
      my( $self ) = shift;
      ...;
  }
  do { my $n; ...; print 'Hurrah!' };

  The yada yada cannot stand in for an expression that is part of a larger statement
  since the ... is also the three-dot version of the range operator
  (see "Range Operators"). These examples of the yada yada are still syntax errors:

  print ...;
  open my($fh), '>', '/dev/passwd' or ...;
  if ( $condition && ... ) { print "Hello\n" };

  There are some cases where Perl can't immediately tell the difference between an
  expression and a statement. For instance, the syntax for a block and an anonymous
  hash reference constructor look the same unless there's something in the braces that
  give Perl a hint. The yada yada is a syntax error if Perl doesn't guess that the
  { ... } is a block. In that case, it doesn't think the ... is the yada yada because
  it's expecting an expression instead of a statement:

  my @transformed = map { ... } @input;  # syntax error

  You can use a ; inside your block to denote that the { ... } is a block and not a
  hash reference constructor. Now the yada yada works:

  my @transformed = map {; ... } @input; # ; disambiguates
  my @transformed = map { ...; } @input; # ; disambiguates

Un-Escaping bytes::* Subroutines (KOI8U software provides)

KOI8U software removes 'bytes::' at head of subroutine name.

  ---------------------------------------
  Before           After     Works as
  ---------------------------------------
  bytes::chr       chr       Byte
  bytes::index     index     Byte
  bytes::length    length    Byte
  bytes::ord       ord       Byte
  bytes::rindex    rindex    Byte
  bytes::substr    substr    Byte
  ---------------------------------------

Ignore Pragmas and Modules

  -----------------------------------------------------------
  Before                    After
  -----------------------------------------------------------
  use strict;               use strict; no strict qw(refs);
  use 5.12.0;               use 5.12.0; no strict qw(refs);
  require utf8;             # require utf8;
  require bytes;            # require bytes;
  require charnames;        # require charnames;
  require I18N::Japanese;   # require I18N::Japanese;
  require I18N::Collate;    # require I18N::Collate;
  require I18N::JExt;       # require I18N::JExt;
  require File::DosGlob;    # require File::DosGlob;
  require Wild;             # require Wild;
  require Wildcard;         # require Wildcard;
  require Japanese;         # require Japanese;
  use utf8;                 # use utf8;
  use bytes;                # use bytes;
  use charnames;            # use charnames;
  use I18N::Japanese;       # use I18N::Japanese;
  use I18N::Collate;        # use I18N::Collate;
  use I18N::JExt;           # use I18N::JExt;
  use File::DosGlob;        # use File::DosGlob;
  use Wild;                 # use Wild;
  use Wildcard;             # use Wildcard;
  use Japanese;             # use Japanese;
  no utf8;                  # no utf8;
  no bytes;                 # no bytes;
  no charnames;             # no charnames;
  no I18N::Japanese;        # no I18N::Japanese;
  no I18N::Collate;         # no I18N::Collate;
  no I18N::JExt;            # no I18N::JExt;
  no File::DosGlob;         # no File::DosGlob;
  no Wild;                  # no Wild;
  no Wildcard;              # no Wildcard;
  no Japanese;              # no Japanese;
  -----------------------------------------------------------

  Comment out pragma to ignore utf8 environment, and Ekoi8u.pm provides these
  functions.
  • Dummy utf8::upgrade

      $num_octets = utf8::upgrade($string);
    
      Returns the number of octets necessary to represent the string.
  • Dummy utf8::downgrade

      $success = utf8::downgrade($string[, FAIL_OK]);
    
      Returns true always.
  • Dummy utf8::encode

      utf8::encode($string);
    
      Returns nothing.
  • Dummy utf8::decode

      $success = utf8::decode($string);
    
      Returns true always.
  • Dummy utf8::is_utf8

      $flag = utf8::is_utf8(STRING);
    
      Returns false always.
  • Dummy utf8::valid

      $flag = utf8::valid(STRING);
    
      Returns true always.
  • Dummy bytes::chr

      This subroutine is same as chr.
  • Dummy bytes::index

      This subroutine is same as index.
  • Dummy bytes::length

      This subroutine is same as length.
  • Dummy bytes::ord

      This subroutine is same as ord.
  • Dummy bytes::rindex

      This subroutine is same as rindex.
  • Dummy bytes::substr

      This subroutine is same as substr.

Environment Variable

 This software uses the flock function for exclusive control. The execution of the
 program is blocked until it becomes possible to read or write the file.
 You can have it not block in the flock function by defining environment variable
 CHAR_NONBLOCK.
 
 Example:
 
   SET CHAR_NONBLOCK=1
 
 (The value '1' doesn't have the meaning)

BUGS, LIMITATIONS, and COMPATIBILITY

I have tested and verified this software using the best of my ability. However, a software containing much regular expression is bound to contain some bugs. Thus, if you happen to find a bug that's in KOI8U software and not your own program, you can try to reduce it to a minimal test case and then report it to the following author's address. If you have an idea that could make this a more useful tool, please let everyone share it.

  • (dummy item to avoid Test::Pod error)

  • cloister of regular expression

    The cloister (?s) and (?i) of a regular expression will not be implemented for the time being. Cloister (?s) can be substituted with the .(dot) and \N on /s modifier. Cloister (?i) can be substituted with \F...\E.

  • Modifier /a /d /l and /u of Regular Expression

    The concept of this software is not to use two or more encoding methods as literal string and literal of regexp in one Perl script. Therefore, modifier /a, /d, /l, and /u are not supported. \d means [0-9] universally.

  • Named Character

    A named character, such \N{GREEK SMALL LETTER EPSILON}, \N{greek:epsilon}, or \N{epsilon} is not supported.

  • Unicode Properties (aka Character Properties) of Regular Expression

    Unicode properties (aka character properties) of regexp are not available. Also (?[]) in regexp of Perl 5.18 is not available. There is no plans to currently support these.

  • Delimiter of String and Regexp

    qq//, q//, qw//, qx//, qr//, m//, s///, tr///, and y/// can't use a wide character as the delimiter.

  • \b{...} Boundaries in Regular Expressions

    Following \b{...} available starting in v5.22 are not supported.

      \b{gcb} or \b{g}   Unicode "Grapheme Cluster Boundary"
      \b{sb}             Unicode "Sentence Boundary"
      \b{wb}             Unicode "Word Boundary"
      \B{gcb} or \B{g}   Unicode "Grapheme Cluster Boundary" doesn't match
      \B{sb}             Unicode "Sentence Boundary" doesn't match
      \B{wb}             Unicode "Word Boundary" doesn't match

AUTHOR

INABA Hitoshi <ina@cpan.org>

This project was originated by INABA Hitoshi.

LICENSE AND COPYRIGHT

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

This software is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

My Goal

P.401 See chapter 15: Unicode of ISBN 0-596-00027-8 Programming Perl Third Edition.

Before the introduction of Unicode support in perl, The eq operator just compared the byte-strings represented by two scalars. Beginning with perl 5.8, eq compares two byte-strings with simultaneous consideration of the UTF8 flag.

/* You are not expected to understand this */

  Information processing model beginning with perl 5.8
 
    +----------------------+---------------------+
    |     Text strings     |                     |
    +----------+-----------|    Binary strings   |
    |  UTF-8   |  Latin-1  |                     |
    +----------+-----------+---------------------+
    | UTF8     |            Not UTF8             |
    | Flagged  |            Flagged              |
    +--------------------------------------------+
    http://perl-users.jp/articles/advent-calendar/2010/casual/4

  Confusion of Perl string model is made from double meanings of
  "Binary string."
  Meanings of "Binary string"
  1. Non-Text string
  2. Digital octet string

  Let's draw again using those term.
 
    +----------------------+---------------------+
    |     Text strings     |                     |
    +----------+-----------|   Non-Text strings  |
    |  UTF-8   |  Latin-1  |                     |
    +----------+-----------+---------------------+
    | UTF8     |            Not UTF8             |
    | Flagged  |            Flagged              |
    +--------------------------------------------+
    |            Digital octet string            |
    +--------------------------------------------+

There are people who don't agree to change in the character string processing model of Perl 5.8. It is impossible to get to agree it to majority of Perl user who hardly ever use Perl. How to solve it by returning to a original method, let's drag out page 402 of the old dusty Programming Perl, 3rd ed. again.

  Information processing model beginning with perl3 or this software
  of UNIX/C-ism.

    +--------------------------------------------+
    |    Text string as Digital octet string     |
    |    Digital octet string as Text string     |
    +--------------------------------------------+
    |       Not UTF8 Flagged, No Mojibake        |
    +--------------------------------------------+

  In UNIX Everything is a File
  - In UNIX everything is a stream of bytes
  - In UNIX the filesystem is used as a universal name space

  Native Encoding Scripting
  - native encoding of file contents
  - native encoding of file name on filesystem
  - native encoding of command line
  - native encoding of environment variable
  - native encoding of API
  - native encoding of network packet
  - native encoding of database

Ideally, I'd like to achieve these five Goals:

  • Goal #1:

    Old byte-oriented programs should not spontaneously break on the old byte-oriented data they used to work on.

    This goal has been achieved by that this software is additional code for perl like utf8 pragma. Perl should work same as past Perl if added nothing.

  • Goal #2:

    Old byte-oriented programs should magically start working on the new character-oriented data when appropriate.

    Still now, 1 octet is counted with 1 by built-in functions length, substr, index, rindex, and pos that handle length and position of string. In this part, there is no change. The length of 1 character of 2 octet code is 2.

    On the other hand, the regular expression in the script is added the multibyte anchoring processing with this software, instead of you.

    figure of Goal #1 and Goal #2.

                                   GOAL#1  GOAL#2
                            (a)     (b)     (c)     (d)     (e)
          +--------------+-------+-------+-------+-------+-------+
          | data         |  Old  |  Old  |  New  |  Old  |  New  |
          +--------------+-------+-------+-------+-------+-------+
          | script       |  Old  |      Old      |      New      |
          +--------------+-------+---------------+---------------+
          | interpreter  |  Old  |              New              |
          +--------------+-------+-------------------------------+
          Old --- Old byte-oriented
          New --- New character-oriented

    There is a combination from (a) to (e) in data, script, and interpreter of old and new. Let's add the Encode module and this software did not exist at time of be written this document and JPerl did exist.

                            (a)     (b)     (c)     (d)     (e)
                                          JPerl,japerl    Encode,KOI8U
          +--------------+-------+-------+-------+-------+-------+
          | data         |  Old  |  Old  |  New  |  Old  |  New  |
          +--------------+-------+-------+-------+-------+-------+
          | script       |  Old  |      Old      |      New      |
          +--------------+-------+---------------+---------------+
          | interpreter  |  Old  |              New              |
          +--------------+-------+-------------------------------+
          Old --- Old byte-oriented
          New --- New character-oriented

    The reason why JPerl is very excellent is that it is at the position of (c). That is, it is not necessary to do a special description to the script to process new character-oriented string. (May the japerl take over JPerl!)

  • Goal #3:

    Programs should run just as fast in the new character-oriented mode as in the old byte-oriented mode.

    It is impossible. Because the following time is necessary.

    (1) Time of escape script for old byte-oriented perl.

    Someday, I want to ask Larry Wall about this goal in the elevator.

  • Goal #4:

    Perl should remain one language, rather than forking into a byte-oriented Perl and a character-oriented Perl.

    JPerl remains one Perl language by forking to two interpreters. However, the Perl core team did not desire fork of the interpreter. As a result, Perl language forked contrary to goal #4.

    A character-oriented perl is not necessary to make it specially, because a byte-oriented perl can already treat the binary data. This software is only an application program of byte-oriented Perl, a filter program.

    And you will get support from the Perl community, when you solve the problem by the Perl script.

    KOI8U software remains one language and one interpreter.

  • Goal #5:

    JPerl users will be able to maintain JPerl by Perl.

    May the JPerl be with you, always.

Back when Programming Perl, 3rd ed. was written, UTF8 flag was not born and Perl is designed to make the easy jobs easy. This software provides programming environment like at that time.

Perl's motto

   Some computer scientists (the reductionists, in particular) would
  like to deny it, but people have funny-shaped minds. Mental geography
  is not linear, and cannot be mapped onto a flat surface without
  severe distortion. But for the last score years or so, computer
  reductionists have been first bowing down at the Temple of Orthogonality,
  then rising up to preach their ideas of ascetic rectitude to any who
  would listen.
 
   Their fervent but misguided desire was simply to squash your mind to
  fit their mindset, to smush your patterns of thought into some sort of
  Hyperdimensional Flatland. It's a joyless existence, being smushed.
  --- Learning Perl on Win32 Systems

  If you think this is a big headache, you're right. No one likes
  this situation, but Perl does the best it can with the input and
  encodings it has to deal with. If only we could reset history and
  not make so many mistakes next time.
  --- Learning Perl 6th Edition

   The most important thing for most people to know about handling
  Unicode data in Perl, however, is that if you don't ever use any Uni-
  code data -- if none of your files are marked as UTF-8 and you don't
  use UTF-8 locales -- then you can happily pretend that you're back in
  Perl 5.005_03 land; the Unicode features will in no way interfere with
  your code unless you're explicitly using them. Sometimes the twin
  goals of embracing Unicode but not disturbing old-style byte-oriented
  scripts has led to compromise and confusion, but it's the Perl way to
  silently do the right thing, which is what Perl ends up doing.
  --- Advanced Perl Programming, 2nd Edition

SEE ALSO

 PERL PUROGURAMINGU
 Larry Wall, Randal L.Schwartz, Yoshiyuki Kondo
 December 1997
 ISBN 4-89052-384-7
 http://www.context.co.jp/~cond/books/old-books.html

 Programming Perl, Second Edition
 By Larry Wall, Tom Christiansen, Randal L. Schwartz
 October 1996
 Pages: 670
 ISBN 10: 1-56592-149-6 | ISBN 13: 9781565921498
 http://shop.oreilly.com/product/9781565921498.do

 Programming Perl, Third Edition
 By Larry Wall, Tom Christiansen, Jon Orwant
 Third Edition  July 2000
 Pages: 1104
 ISBN 10: 0-596-00027-8 | ISBN 13: 9780596000271
 http://shop.oreilly.com/product/9780596000271.do

 The Perl Language Reference Manual (for Perl version 5.12.1)
 by Larry Wall and others
 Paperback (6"x9"), 724 pages
 Retail Price: $39.95 (pound 29.95 in UK)
 ISBN-13: 978-1-906966-02-7
 http://www.network-theory.co.uk/perl/language/

 Perl Pocket Reference, 5th Edition
 By Johan Vromans
 Publisher: O'Reilly Media
 Released: July 2011
 Pages: 102
 http://shop.oreilly.com/product/0636920018476.do

 Programming Perl, 4th Edition
 By: Tom Christiansen, brian d foy, Larry Wall, Jon Orwant
 Publisher: O'Reilly Media
 Formats: Print, Ebook, Safari Books Online
 Released: March 2012
 Pages: 1130
 Print ISBN: 978-0-596-00492-7 | ISBN 10: 0-596-00492-3
 Ebook ISBN: 978-1-4493-9890-3 | ISBN 10: 1-4493-9890-1
 http://shop.oreilly.com/product/9780596004927.do

 Perl Cookbook
 By Tom Christiansen, Nathan Torkington
 August 1998
 Pages: 800
 ISBN 10: 1-56592-243-3 | ISBN 13: 978-1-56592-243-3
 http://shop.oreilly.com/product/9781565922433.do

 Perl Cookbook, Second Edition
 By Tom Christiansen, Nathan Torkington
 Second Edition  August 2003
 Pages: 964
 ISBN 10: 0-596-00313-7 | ISBN 13: 9780596003135
 http://shop.oreilly.com/product/9780596003135.do

 Perl in a Nutshell, Second Edition
 By Stephen Spainhour, Ellen Siever, Nathan Patwardhan
 Second Edition  June 2002
 Pages: 760
 Series: In a Nutshell
 ISBN 10: 0-596-00241-6 | ISBN 13: 9780596002411
 http://shop.oreilly.com/product/9780596002411.do

 Learning Perl on Win32 Systems
 By Randal L. Schwartz, Erik Olson, Tom Christiansen
 August 1997
 Pages: 306
 ISBN 10: 1-56592-324-3 | ISBN 13: 9781565923249
 http://shop.oreilly.com/product/9781565923249.do

 Learning Perl, Fifth Edition
 By Randal L. Schwartz, Tom Phoenix, brian d foy
 June 2008
 Pages: 352
 Print ISBN:978-0-596-52010-6 | ISBN 10: 0-596-52010-7
 Ebook ISBN:978-0-596-10316-3 | ISBN 10: 0-596-10316-6
 http://shop.oreilly.com/product/9780596520113.do

 Learning Perl, 6th Edition
 By Randal L. Schwartz, brian d foy, Tom Phoenix
 June 2011
 Pages: 390
 ISBN-10: 1449303587 | ISBN-13: 978-1449303587
 http://shop.oreilly.com/product/0636920018452.do

 Advanced Perl Programming, 2nd Edition
 By Simon Cozens
 June 2005
 Pages: 300
 ISBN-10: 0-596-00456-7 | ISBN-13: 978-0-596-00456-9
 http://shop.oreilly.com/product/9780596004569.do

 Perl RESOURCE KIT UNIX EDITION
 Futato, Irving, Jepson, Patwardhan, Siever
 ISBN 10: 1-56592-370-7
 http://shop.oreilly.com/product/9781565923706.do

 Perl Resource Kit -- Win32 Edition
 Erik Olson, Brian Jepson, David Futato, Dick Hardt
 ISBN 10:1-56592-409-6
 http://shop.oreilly.com/product/9781565924093.do

 MODAN Perl NYUMON
 By Daisuke Maki
 2009/2/10
 Pages: 344
 ISBN 10: 4798119172 | ISBN 13: 978-4798119175
 http://www.seshop.com/product/detail/10250/

 Understanding Japanese Information Processing
 By Ken Lunde
 January 1900
 Pages: 470
 ISBN 10: 1-56592-043-0 | ISBN 13: 9781565920439
 http://shop.oreilly.com/product/9781565920439.do

 CJKV Information Processing
 Chinese, Japanese, Korean & Vietnamese Computing
 By Ken Lunde
 First Edition  January 1999
 Pages: 1128
 ISBN 10: 1-56592-224-7 | ISBN 13: 9781565922242
 http://shop.oreilly.com/product/9781565922242.do

 Mastering Regular Expressions, Second Edition
 By Jeffrey E. F. Friedl
 Second Edition  July 2002
 Pages: 484
 ISBN 10: 0-596-00289-0 | ISBN 13: 9780596002893
 http://shop.oreilly.com/product/9780596002893.do

 Mastering Regular Expressions, Third Edition
 By Jeffrey E. F. Friedl
 Third Edition  August 2006
 Pages: 542
 ISBN 10: 0-596-52812-4 | ISBN 13:9780596528126
 http://shop.oreilly.com/product/9780596528126.do

 Regular Expressions Cookbook
 By Jan Goyvaerts, Steven Levithan
 May 2009
 Pages: 512
 ISBN 10:0-596-52068-9 | ISBN 13: 978-0-596-52068-7
 http://shop.oreilly.com/product/9780596520694.do

 Regular Expressions Cookbook, 2nd Edition
 By Jan Goyvaerts, Steven Levithan
 Final Release Date: August 2012
 Pages: 612
 ISBN: 978-1-4493-1943-4 | ISBN 10:1-4493-1943-2

 JIS KANJI JITEN
 By Kouji Shibano
 Pages: 1456
 ISBN 4-542-20129-5
 http://www.webstore.jsa.or.jp/lib/lib.asp?fn=/manual/mnl01_12.htm

 UNIX MAGAZINE
 1993 Aug
 Pages: 172
 T1008901080816 ZASSHI 08901-8
 http://ascii.asciimw.jp/books/books/detail/978-4-7561-5008-0.shtml

 LINUX NIHONGO KANKYO
 By YAMAGATA Hiroo, Stephen J. Turnbull, Craig Oda, Robert J. Bickel
 June, 2000
 Pages: 376
 ISBN 4-87311-016-5
 http://www.oreilly.co.jp/books/4873110165/

 MacPerl Power and Ease
 By Vicki Brown, Chris Nandor
 April 1998
 Pages: 350
 ISBN 10: 1881957322 | ISBN 13: 978-1881957324
 http://www.amazon.com/Macperl-Power-Ease-Vicki-Brown/dp/1881957322

 Windows NT Shell Scripting
 By Timothy Hill
 April 27, 1998
 Pages: 400
 ISBN 10: 1578700477 | ISBN 13: 9781578700479
 http://search.barnesandnoble.com/Windows-NT-Shell-Scripting/Timothy-Hill/e/9781578700479/

 Windows(R) Command-Line Administrators Pocket Consultant, 2nd Edition
 By William R. Stanek
 February 2009
 Pages: 594
 ISBN 10: 0-7356-2262-0 | ISBN 13: 978-0-7356-2262-3
 http://shop.oreilly.com/product/9780735622623.do

 Kaoru Maeda, Perl's history Perl 1,2,3,4
 http://www.slideshare.net/KaoruMaeda/perl-perl-1234

 nurse, What is "string"
 http://d.hatena.ne.jp/nurse/20141107#1415355181

 NISHIO Hirokazu, What's meant "string as a sequence of characters"?
 http://d.hatena.ne.jp/nishiohirokazu/20141107/1415286729

 nurse, History of Japanese EUC 22:00
 http://d.hatena.ne.jp/nurse/20090308/1236517235

 Mike Whitaker, Perl And Unicode
 http://www.slideshare.net/Penfold/perl-and-unicode

 Ricardo Signes, Perl 5.14 for Pragmatists
 http://www.slideshare.net/rjbs/perl-514-8809465

 Ricardo Signes, What's New in Perl? v5.10 - v5.16 #'
 http://www.slideshare.net/rjbs/whats-new-in-perl-v510-v516

 YAP(achimon)C::Asia Hachioji 2016 mid in Shinagawa
 Kenichi Ishigaki (@charsbar) July 3, 2016 YAP(achimon)C::Asia Hachioji 2016mid
 https://www.slideshare.net/charsbar/cpan-63708689

 CPAN Directory INABA Hitoshi
 http://search.cpan.org/~ina/

 BackPAN
 http://backpan.perl.org/authors/id/I/IN/INA/

 Recent Perl packages by "INABA Hitoshi"
 http://code.activestate.com/ppm/author:INABA-Hitoshi/

ACKNOWLEDGEMENTS

This software was made referring to software and the document that the following hackers or persons had made. I am thankful to all persons.

 Rick Yamashita, Shift_JIS
 ttp://furukawablog.spaces.live.com/Blog/cns!1pmWgsL289nm7Shn7cS0jHzA!2225.entry (dead link)
 ttp://shino.tumblr.com/post/116166805/1981-us-jis
 (add 'h' at head)
 http://www.wdic.org/w/WDIC/%E3%82%B7%E3%83%95%E3%83%88JIS

 Larry Wall, Perl
 http://www.perl.org/

 Kazumasa Utashiro, jcode.pl
 http://search.cpan.org/~utashiro/
 ftp://ftp.iij.ad.jp/pub/IIJ/dist/utashiro/perl/
 http://log.utashiro.com/pub/2006/07/jkondo_a580.html

 Jeffrey E. F. Friedl, Mastering Regular Expressions
 http://regex.info/

 SADAHIRO Tomoyuki, The right way of using Shift_JIS
 http://homepage1.nifty.com/nomenclator/perl/shiftjis.htm
 http://search.cpan.org/~sadahiro/

 Yukihiro "Matz" Matsumoto, YAPC::Asia2006 Ruby on Perl(s)
 http://www.rubyist.net/~matz/slides/yapc2006/

 jscripter, For jperl users
 http://homepage1.nifty.com/kazuf/jperl.html

 Bruce., Unicode in Perl
 http://www.rakunet.org/tsnet/TSabc/18/546.html

 Hiroaki Izumi, Perl5.8/Perl5.10 is not useful on the Windows.
 http://dl.dropbox.com/u/23756062/perlwin.html
 https://sites.google.com/site/hiroa63iz/perlwin

 TSUKAMOTO Makio, Perl memo/file path of Windows
 http://digit.que.ne.jp/work/wiki.cgi?Perl%E3%83%A1%E3%83%A2%2FWindows%E3%81%A7%E3%81%AE%E3%83%95%E3%82%A1%E3%82%A4%E3%83%AB%E3%83%91%E3%82%B9

 chaichanPaPa, Matching Shift_JIS file name
 http://d.hatena.ne.jp/chaichanPaPa/20080802/1217660826

 SUZUKI Norio, Jperl
 http://homepage2.nifty.com/kipp/perl/jperl/

 WATANABE Hirofumi, Jperl
 http://www.cpan.org/src/5.0/jperl/
 http://search.cpan.org/~watanabe/
 ftp://ftp.oreilly.co.jp/pcjp98/watanabe/jperlconf.ppt

 Chuck Houpt, Michiko Nozu, MacJPerl
 http://habilis.net/macjperl/index.j.html

 Kenichi Ishigaki, Pod-PerldocJp, Welcome to modern Perl world
 http://search.cpan.org/dist/Pod-PerldocJp/
 http://gihyo.jp/dev/serial/01/modern-perl/0031
 http://gihyo.jp/dev/serial/01/modern-perl/0032
 http://gihyo.jp/dev/serial/01/modern-perl/0033

 Fuji, Goro (gfx), Perl Hackers Hub No.16
 http://gihyo.jp/dev/serial/01/perl-hackers-hub/001602

 Dan Kogai, Encode module
 http://search.cpan.org/dist/Encode/
 http://www.archive.org/details/YAPCAsia2006TokyoPerl58andUnicodeMythsFactsandChanges (video)
 http://yapc.g.hatena.ne.jp/jkondo/ (audio)

 Takahashi Masatuyo, JPerl Wiki
 http://ja.jperl.wikia.com/wiki/JPerl_Wiki

 Juerd, Perl Unicode Advice
 http://juerd.nl/site.plp/perluniadvice

 daily dayflower, 2008-06-25 perluniadvice
 http://d.hatena.ne.jp/dayflower/20080625/1214374293

 Unicode issues in Perl
 http://www.i-programmer.info/programming/other-languages/1973-unicode-issues-in-perl.html

 Jesse Vincent, Compatibility is a virtue
 http://www.nntp.perl.org/group/perl.perl5.porters/2010/05/msg159825.html

 Tokyo-pm archive
 http://mail.pm.org/pipermail/tokyo-pm/
 http://mail.pm.org/pipermail/tokyo-pm/1999-September/001844.html
 http://mail.pm.org/pipermail/tokyo-pm/1999-September/001854.html

 Error: Runtime exception on jperl 5.005_03
 http://www.rakunet.org/tsnet/TSperl/12/374.html
 http://www.rakunet.org/tsnet/TSperl/12/375.html
 http://www.rakunet.org/tsnet/TSperl/12/376.html
 http://www.rakunet.org/tsnet/TSperl/12/377.html
 http://www.rakunet.org/tsnet/TSperl/12/378.html
 http://www.rakunet.org/tsnet/TSperl/12/379.html
 http://www.rakunet.org/tsnet/TSperl/12/380.html
 http://www.rakunet.org/tsnet/TSperl/12/382.html

 ruby-list
 http://blade.nagaokaut.ac.jp/ruby/ruby-list/index.shtml
 http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-list/2440
 http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-list/2446
 http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-list/2569
 http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-list/9427
 http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-list/9431
 http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-list/10500
 http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-list/10501
 http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-list/10502
 http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-list/12385
 http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-list/12392
 http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-list/12393
 http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-list/19156

 Object-oriented with Perl
 http://www.freeml.com/perl-oo/486
 http://www.freeml.com/perl-oo/487
 http://www.freeml.com/perl-oo/490
 http://www.freeml.com/perl-oo/491
 http://www.freeml.com/perl-oo/492
 http://www.freeml.com/perl-oo/494
 http://www.freeml.com/perl-oo/514