SimplePie正则误差

Question

用PHP5.3开发xampp上SimplePie的1.3dev版本。

我能够获得一个RSS提要并显示它，但是我会为获取的每一项获取以下错误：

警告: preg_match() function.preg-match:编译失败:在C:\xampp\htdocs\simplepie.php第5877行的偏移量562处没有重复 警告: preg_match() function.preg-match:编译失败:在C:\xampp\htdocs\simplepie.php中的第5965行偏移量509处没有重复 警告: preg_match() function.preg-match:编译失败:在C:\xampp\htdocs\simplepie.php第6031行的偏移量509处没有重复

发生错误的函数：

    /**
 * Parse RFC2822's date format
 *
 * @access protected
 * @return int Timestamp
 */
public function date_rfc2822($date)
{
    static $pcre;
    if (!$pcre)
    {
        $wsp = '[\x09\x20]';
        $fws = '(?:' . $wsp . '+|' . $wsp . '*(?:\x0D\x0A' . $wsp . '+)+)';
        $optional_fws = $fws . '?';
        $day_name = $this->day_pcre;
        $month = $this->month_pcre;
        $day = '([0-9]{1,2})';
        $hour = $minute = $second = '([0-9]{2})';
        $year = '([0-9]{2,4})';
        $num_zone = '([+\-])([0-9]{2})([0-9]{2})';
        $character_zone = '([A-Z]{1,5})';
        $zone = '(?:' . $num_zone . '|' . $character_zone . ')';
        $pcre = '/(?:' . $optional_fws . $day_name . $optional_fws . ',)?' . $optional_fws . $day . $fws . $month . $fws . $year . $fws . $hour . $optional_fws . ':' . $optional_fws . $minute . '(?:' . $optional_fws . ':' . $optional_fws . $second . ')?' . $fws . $zone . '/i';
    }
    if (preg_match($pcre, $this->remove_rfc2822_comments($date), $match))

/**
 * Parse RFC850's date format
 *
 * @access protected
 * @return int Timestamp
 */
public function date_rfc850($date)
{
    static $pcre;
    if (!$pcre)
    {
        $space = '[\x09\x20]+';
        $day_name = $this->day_pcre;
        $month = $this->month_pcre;
        $day = '([0-9]{1,2})';
        $year = $hour = $minute = $second = '([0-9]{2})';
        $zone = '([A-Z]{1,5})';
        $pcre = '/^' . $day_name . ',' . $space . $day . '-' . $month . '-' . $year . $space . $hour . ':' . $minute . ':' . $second . $space . $zone . '$/i';
    }
    if (preg_match($pcre, $date, $match))

/**
 * Parse C99's asctime()'s date format
 *
 * @access protected
 * @return int Timestamp
 */
public function date_asctime($date)
{
    static $pcre;
    if (!$pcre)
    {
        $space = '[\x09\x20]+';
        $wday_name = $this->day_pcre;
        $mon_name = $this->month_pcre;
        $day = '([0-9]{1,2})';
        $hour = $sec = $min = '([0-9]{2})';
        $year = '([0-9]{4})';
        $terminator = '\x0A?\x00?';
        $pcre = '/^' . $wday_name . $space . $mon_name . $space . $day . $space . $hour . ':' . $min . ':' . $sec . $space . $year . $terminator . '$/i';
    }
    if (preg_match($pcre, $date, $match))

错误引用的行是每个函数(您可以在这里看到完整的代码)的最后一个if表达式。

我认为每个函数在每个$pcre中都有错误的正则表达式。

谢谢

Answer 1

如果regex有什么问题，它不应该编译。

然而，$this->day_pcre和$this->month_pcre可能包含可能使正则表达式变差的元字符。最好检查一下。

我替换了“星期一”和“十月”，并在Ideone上运行了它。似乎很管用。

顺便提一句，你可能需要交换$fws -

来自$fws = '(?:' . $wsp . '+|' . $wsp . '*(?:\x0D\x0A' . $wsp . '+)+)'

转到$fws = '(?:(?:(?:\x0D\x0A)?' . $wsp . ')+)'

因为它们是等价的，而且可能更有效率。

在您的函数中，您应该打印出用于

$day/$month/$pcre变量否则你怎么能期望调试它呢？

可能是别的什么，我不知道。

以下是我得到的：http://ideone.com/zJ5vE

代码

<?php

date_asctime( "Mon Oct 21 11:21:31 2012\x0A" );
date_asctime( "Mon Oct 22 12:22:32 2012\x0A" );
date_asctime( "Mon Oct 23 13:23:33 2012\x0A" );

print("==================\n");

date_rfc2822( 'Mon, 21 Oct 2012 21:01 -1011' );
date_rfc2822( 'Mon, 22 Oct 2012 22:02 -1012' );
date_rfc2822( 'Mon, 23 Oct 2012 23:03 -1013' );


/**
 * Parse C99's asctime()'s date format
 *
 * @access protected
 * @return int Timestamp
 */
function date_asctime($date)
{
    static $pcre;
    if (!$pcre)
    {
        $space = '[\x09\x20]+';

        $wday_name = 'Mon';  //$this->day_pcre;
        $mon_name = 'Oct';   //$this->month_pcre;

        $day = '([0-9]{1,2})';
        $hour = $sec = $min = '([0-9]{2})';
        $year = '([0-9]{4})';
        $terminator = '\x0A?\x00?';
        $pcre = '/^' . $wday_name . $space . $mon_name . $space . $day . $space . $hour . ':' . $min . ':' . $sec . $space . $year . $terminator . '$/i';
    }
    if (preg_match($pcre, $date, $match))
    {
       print_r($match);
    }
}


/**
 * Parse RFC2822's date format
 *
 * @access protected
 * @return int Timestamp
 */
function date_rfc2822($date)
{
    static $pcre;
    if (!$pcre)
    {
        $wsp = '[\x09\x20]';

         // $fws = '(?:' . $wsp . '+|' . $wsp . '*(?:\x0D\x0A' . $wsp . '+)+)';
        $fws = '(?:(?:(?:\x0D\x0A)?' . $wsp . ')+)';
        $optional_fws = $fws . '?';

        $day_name = 'Mon';  //$this->day_pcre;
        $month = 'Oct';     //$this->month_pcre;

        $day = '([0-9]{1,2})';
        $hour = $minute = $second = '([0-9]{2})';
        $year = '([0-9]{2,4})';
        $num_zone = '([+\-])([0-9]{2})([0-9]{2})';
        $character_zone = '([A-Z]{1,5})';
        $zone = '(?:' . $num_zone . '|' . $character_zone . ')';
        $pcre = '/(?:' . $optional_fws . $day_name . $optional_fws . ',)?' . $optional_fws . $day . $fws . $month . $fws . $year . $fws . $hour . $optional_fws . ':' . $optional_fws . $minute . '(?:' . $optional_fws . ':' . $optional_fws . $second . ')?' . $fws . $zone . '/i';
    }
    // if (preg_match($pcre, $this->remove_rfc2822_comments($date), $match))
    if (preg_match($pcre, $date, $match))
    {
       print_r($match);
    }
} 
?>

输出

Array
(
    [0] => Mon Oct 21 11:21:31 2012

    [1] => 21
    [2] => 11
    [3] => 21
    [4] => 31
    [5] => 2012
)
Array
(
    [0] => Mon Oct 22 12:22:32 2012

    [1] => 22
    [2] => 12
    [3] => 22
    [4] => 32
    [5] => 2012
)
Array
(
    [0] => Mon Oct 23 13:23:33 2012

    [1] => 23
    [2] => 13
    [3] => 23
    [4] => 33
    [5] => 2012
)
==================
Array
(
    [0] => Mon, 21 Oct 2012 21:01 -1011
    [1] => 21
    [2] => 2012
    [3] => 21
    [4] => 01
    [5] => 
    [6] => -
    [7] => 10
    [8] => 11
)
Array
(
    [0] => Mon, 22 Oct 2012 22:02 -1012
    [1] => 22
    [2] => 2012
    [3] => 22
    [4] => 02
    [5] => 
    [6] => -
    [7] => 10
    [8] => 12
)
Array
(
    [0] => Mon, 23 Oct 2012 23:03 -1013
    [1] => 23
    [2] => 2012
    [3] => 23
    [4] => 03
    [5] => 
    [6] => -
    [7] => 10
    [8] => 13
)