CLXIII. Tokenizer Functions

Introduzione

The tokenizer functions provide an interface to the PHP tokenizer embedded in the Zend Engine. Using these functions you may write your own PHP source analyzing or modification tools without having to deal with the language specification at the lexical level.

Requisiti

Non sono necessarie librerie esterne per utilizzare questo modulo.

Installazione

Beginning with PHP 4.3.0 these functions are enabled by default. For older versions you have to configure and compile PHP with --enable-tokenizer. You can disable tokenizer support with --disable-tokenizer.

La versione per Windows di PHP ha già compilato il supporto per questo modulo. Non occorre caricare alcun modulo addizionale per potere utilizzare queste funzioni.

Nota: Builtin support for tokenizer is available with PHP 4.3.0.

Costanti predefinite

When the extension has either been compiled into PHP or dynamically loaded at runtime, the tokens listed in Appendice Q are defined as constants.

Esempi

Here is a simple example PHP scripts using the tokenizer that will read in a PHP file, strip all comments from the source and print the pure code only.

Esempio 1. Strip comments with the tokenizer


<?php
/*
 * T_ML_COMMENT does not exist in PHP 5.
 * The following three lines define it in order to
 * preserve backwards compatibility.
 *
 * The next two lines define the PHP 5 only T_DOC_COMMENT,
 * which we will mask as T_ML_COMMENT for PHP 4.
 */
if (!defined('T_ML_COMMENT')) {
    define('T_ML_COMMENT', T_COMMENT);
} else {
    define('T_DOC_COMMENT', T_ML_COMMENT);
}

$source = file_get_contents('example.php');
$tokens = token_get_all($source);

foreach ($tokens as $token) {
    if (is_string($token)) {
        // simple 1-character token
        echo $token;
    } else {
        // token array
        list($id, $text) = $token;
 
        switch ($id) { 
            case T_COMMENT: 
            case T_ML_COMMENT: // we've defined this
            case T_DOC_COMMENT: // and this
                // no action on comments
                break;

            default:
                // anything else -> output "as is"
                echo $text;
                break;
        }
    }
}
?>

Sommario
token_get_all -- Split given source into PHP tokens
token_name -- Get the symbolic name of a given PHP token