如何获得带有preg_replace的替换文本 - How can you get the replaced text with preg_replace?

How can you get the replaced text with preg_replace?

我正在使用PHP中的preg_replace函数，并试图用 bit.ly 缩短的链接替换用户提交的url：

$comment = preg_replace( '/(http|ftp)+(s)?:('/'/)(('w|'.)+)('/)?('S+)?/i', '', $strText );

这将仅显示注释并"清除"URL。问题是我如何从文本中获取 URL 并在以后附加它？

preg_replace_callback((

php.net 的例子：

<?php
// this text was used in 2002
// we want to get this up to date for 2003
$text = "April fools day is 04/01/2002'n";
$text.= "Last christmas was 12/24/2001'n";
// the callback function
function next_year($matches)
{
  // as usual: $matches[0] is the complete match
  // $matches[1] the match for the first subpattern
  // enclosed in '(...)' and so on
  return $matches[1].($matches[2]+1);
}
echo preg_replace_callback(
            "|('d{2}/'d{2}/)('d{4})|",
            "next_year",
            $text);
?>

定义替换 URL 的回调函数。它将接收匹配项作为参数，并在内部根据这些匹配项形成替换字符串。