What is ext/perl?
=================
  This extension allows embedding of Perl Interpreter into PHP5 to:
    * execute Perl files
    * evaluate Perl code
    * access values of Perl variables
    * call Perl subroutines
    * instantiate and manipulate of Perl objects
Requirements
============
  PHP 5.0.0RC2 or later
  Perl 5.8.0 or later
Quick install
=============
  Step 1. Compile this extension. PHP_PREFIX and PERL_PREFIX mast point to real
          PHP and Perl instalation prefixes.
    export PHP_PREFIX="/usr"
    export PERL_PREFIX="/usr"
    $PHP_PREFIX/bin/phpize
    ./configure --with-perl=$PERL_PREFIX --with-php-config=$PHP_PREFIX/bin/php-config
    make  
  Step 2. Install the extension (this step can require root privileges)
    make install
  Step 3. Add perl extension into your php.ini (this step can require root privileges)
    extension=perl.so
Windows Installation Notes
==========================
  Step 1. Download ActivePerl binaries for Windows from 
          https://www.activestate.com/Products/ActivePerl/
          and install them.
  Step 2. Put this extension into corresponding PHP source tree (into ext/perl)
  Step 3. Compile the extension
    SET PERL_HOME=C:\perl
    msdev perl.dsp /MAKE "perl - Win32 Release_TS"
  Step 4. Copy php_perl.dll (from Release_TS) to PHP extension dir
  Step 5. Add perl extension into your php.ini
    extension=php_perl.dll
PHP API
=======
  new Perl()
  ----------
    Creates perl interpreter. It allows
    * reading and modifying of Perl variables
    * calling Perl functions
    * evaluating Perl code
    * loading and executing exteranl Perl files
    Examples:
      $perl = new Perl();
      var_dump($perl->x);        // print scalar Perl variable - $x
      var_dump($perl->array->x); // print array Perl variable - @x
      var_dump($perl->hash->x);  // print hash Perl variable - %x
      $perl->func();             // call Perl function 'func' in void context
      $x = $perl->func();        // call Perl function 'func' in scalar context
      $y = $perl->array->func(); // call Perl function 'func' in array context            
      $y = $perl->hash->func();  // call Perl function 'func' in hash context
      $perl->eval('use Digest::MD5');
      echo $perl->{'Digest::MD5::md5_hex'}('Hello');
  
  Perl->eval($perl_code)
  ----------------------
    Evaluates Perl code and returns result. If Perl code is invalid it will
    throw PHP exception. 
    Exampes:
      $perl = new Perl();
      $perl->eval('require "test.pl";');
      echo $perl->eval($x.'+'.$y.';');
      $perl->eval('$z='.$x.'+'.$y.';');
    By default Perl code is evaluated in scalar context, but it can be 
    evaluated in array or hash context too.
    Exampes:
      $perl = new Perl();
      $perl->eval('("a","b","c")');                  // eval in void context
      var_dump($perl->eval('("a","b","c")'));        // eval in scalar context
      var_dump($perl->array->eval('("a","b","c")')); // eval in array context
      var_dump($perl->hash->eval('("a","b","c")'));  // eval in hash context
  Perl->require($perl_file_name)
  ------------------------------
    Loads and executes Perl file. It doesn't return any value. If required Perl
    file doesn't exist or invalid it will throw PHP exception.
    Examples:
      $perl = new Perl();
      $perl->require('test.pl');
  new Perl($perl_class_name[, $constructor = "new"[, ...]])
  -----------------------------------------------------
    Creates an instance of Perl class through calling specified constructor
    or "new" if constructor is not specified. Additional parameters passed
    to Perl's constructor. The created object allows:
    * reading and modifying of object properties
    * calling methods
    * cloning
    Examples:
      $x = new Perl("Test");
      $y = new Perl("Test","copy",$x);
      $z = clone $y;
      echo $z->property;
      echo $z->method(1,2,3);
    Methods can be called in array or hash context in the same way as Perl
    functions, but all properties are acessable directly (without array or
    hash modifiers).
    Examples:
      $x = new Perl("Test");
      $x->f();                  // call method "f" in void context
      var_dump($x->f());        // call method "f" in scalar context
      var_dump($x->array->f()); // call method "f" in array context
      var_dump($x->hash->f());  // call method "f" in hash context
Known BUGS and limitations
==========================
  *  Perl objects passed between Perl and PHP by reference all other data type
     (including arrays and hashes) passed by value. So modification of Perl's
     arrays and hashes in PHP will not have effect in Perl.
     $x = $perl->array->x;
     $x[0] = 1; // Perl's array @x still unmodifyed
     
     But you can use PHP references to do this. The following code works fine.
     
     $x = &$perl->array->x;
     $x[0] = 1; // Modifies Perl's array @x
  *  pecl/perl can't call internal Perl functions
     (print, die, ...).
This extension was testd on RedHat Linux 9.0 with PHP 5.0.0RC2-dev (non ZTS build)
and perl-5.8.0 (installed from RPM) and on Windows 2000 with PHP-5.0.0RC2-dev
(ZTS build) and perl-5.8.0.