preg_grep

说明

array preg_grep ( string pattern, array input )

preg_grep() 返回一个数组，其中包括了 input 数组中与给定的 pattern 模式相匹配的单元。

自 PHP 4.0.4 起，preg_grep() 返回的结果使用从输入数组来的键名进行索引。如果不希望这样的结果，用 array_values() 对 preg_grep() 返回的结果重新索引。

例子 1. preg_grep() 例子
<?php // return all array elements // containing floating point numbers $fl_array = preg_grep ("/^(\d+)?\.\d+$/", $array); ?>

add a note User Contributed Notes

tobyf at web dot de
24-May-2006 03:39


For older PHP versions (> 4.2.0) you can use this function:



<?php

function c_preg_grep($pattern,&$array,$flag=false)

{

    if ($flag != PREG_GREP_INVERT)

    {

        return preg_grep($pattern,$array);

    }

    else

    {

        $remove = preg_grep($pattern,$array);

        return array_diff($array,$remove);

    }

}

?>

ak85 at yandex dot ru
03-Aug-2005 01:28


If U wanna find substring without word "BADWORD" U can use this expression:

/((?:(?!BADWORD).)*)/s

For example:

preg_match_all('/<b>((?:(?!</b>).)*)</b>/is',$string,$matches);

// U can find at the $matches substrings of $string between '<b>' and '</b>' without the same tag '</b>'



// Was found at O'Reilly Rerl Cookbook Russian Edition 2001

erik dot dobecky at NOSPAM dot fi-us dot com
30-Apr-2005 12:15


A useful way that we have developed filters against SQL injection attempts is to preg_grep the $_REQUEST global with the following regular expression (regex):



   '/[\'")]* *[oO][rR] *.*(.)(.) *= *\\2(?:--)?\\1?/'



which is used simply as:

<?php

$SQLInjectionRegex = '/[\'")]* *[oO][rR] *.*(.)(.) *= *\\2(?:--)?\\1?/';

$suspiciousQueryItems = preg_grep($SQLInjectionRegex, $_REQUEST);

?>



which matches any of the following (case insensitive, a=any char) strings (entirely):



' or 1=1--

" or 1=1--

or 1=1--

' or 'a'='a

" or "a"="a

') or ('a'='a

Matt AKA Junkie
06-Jun-2004 03:05


To grep using preg_* from a string instead of an array, use preg_match_all().

zac at slac dot stanford dot edu
27-Jul-2002 10:02


preg_grep takes a third argument (PREG_GREP_INVERT) which negates the pattern matching behaviour, just like the "-v" flag to the grep command.



EXAMPLE:

$food = array('apple', 'banana', 'squid', 'pear');

$fruits = preg_grep("/squid/", $food, PREG_GREP_INVERT);

echo "Food  "; print_r($food);

echo "Fruit "; print_r($fruits);



RESULTS IN:

Food  Array

(

    [0] => apple

    [1] => banana

    [2] => squid

    [3] => pear

)

Fruit Array

(

    [0] => apple

    [1] => banana

    [3] => pear

)

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