preg_match 匹配 src=、background= 和 url(..)

Question

我想找到一个正则表达式，可以找到（在给定的 HTML 中）以下图像：

• 捕获于： src=""
• 捕获于： src=''
• 捕获于：background=""
• 捕获于：background=''
• 捕获于：url("")
• 捕获于： url('')
• 捕获于： 但这些是

到目前为止，我想出了：

preg_match_all("/src=((\"|'|)?(.*\.(png|gif|jpg))(\"|'|))/Ui", $strHTML, $arrMatches);

preg_match_all("/background=((\"|'|)?(.*\.(png|gif|jpg))(\"|'|))/Ui", $strHTML, $arrMatches);

preg_match_all("/url\((\"|'|)?((.*\.(png|gif|jpg))(\"|'|))\)/Ui", $strHTML, $arrMatches);

不完整的，因为它们不包含前缀（src/background/url）。另外，在安全方面，我认为它们可以进一步改进，以防止有人进入 src="http://somesite.com/someurl.exe?ext=jpg"

任何正确方向的帮助都是赞赏。

编辑：

我想我明白了，尽管代码肯定可以改进，甚至可能组合和/或优化:)

/* match CSS url() links */

preg_match_all("/(url\((\"|'|)(.*\.(png|gif|jpg|jpeg))(\"|'|)\))/Ui", $strHTML, $arrMatches);

Array
(
    [0] => Array
        (
            [0] => url('test1.gif')
            [1] => url(test2.gif)
            [2] => url("test3.gif")
        )

    [1] => Array
        (
            [0] => url('test1.gif')
            [1] => url(test2.gif)
            [2] => url("test3.gif")
        )

    [2] => Array
        (
            [0] => '
            [1] => 
            [2] => "
        )

    [3] => Array
        (
            [0] => test1.gif
            [1] => test2.gif
            [2] => test3.gif
        )

    [4] => Array
        (
            [0] => gif
            [1] => gif
            [2] => gif
        )

    [5] => Array
        (
            [0] => '
            [1] => 
            [2] => "
        )

)

/* match img links */
preg_match_all("/(src=(\"\'??)(.*\.(png|gif|jpg|jpeg))(\"\'??))/Ui", $strHTML, $arrMatches);

/* match background links */
preg_match_all("/(background=(\"\'??)(.*\.(png|gif|jpg|jpeg))(\"\'??))/Ui", $strHTML, $arrMatches);

Answer 1

如果您确定这些属性名称（src、url 和背景）...

$arr = array(
    'url("http://somesite.com/someurl.exe?src=jpg")',
    'url(http://somesite.com/someurl.exe?src=jpg)',
    'src="http://somesite.com/someurl.exe?src=jpg"',
    'src="http://somesite.com/someurl.exe?ext=jpg"',
    'background="http://somesite.com/someurl.exe?src=jpg"'
);
foreach ($arr as $str) {
    preg_match_all('/(?<=src=|background=|url\()(\'|")?(?<image>.*?)(?=\1|\))/i',$str,$matches);
    echo $str;
    foreach($matches['image'] as $img) {
        echo "\nimage: <b>$img</b>\n";
    }
    echo "\n";
}