CLXVII. Tokenizer Functions

简介

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.

需求

要编译本扩展模块无需外部库文件。

安装

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.

PHP 的 Windows 版本已经内置该扩展模块的支持。无需加载任何附加扩展库即可使用这些函数。

注意: Built-in support for tokenizer is available as of PHP 4.3.0.

预定义常量

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

范例

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.

例 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;
        }
    }
}
?>

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