用 PHP 替换文本中的链接

在您的正则表达式中，您已经将冒号和两个斜杠设置为强制性的。

这一行应该纠正：

preg_replace('/(http|https)?(:)?('/'/)?(('w|'.)+)('/)?('S+)?/i', '<a href="'0" target="_blank" class="lgray">'0</a>',$domains);

为了获得更好的答案，请尝试查看正则表达式模式以匹配带或不带 http://www 的 url

使用Claus Witt的链接并稍微修改一下就可以完成了这项工作。不过，他给出的preg_replace不起作用。这是我所做的：

$regex = "(((https?|ftp)':'/'/)|(www))";//Scheme
$regex .= "([a-z0-9-.]*)'.([a-z]{2,4})";//Host or IP
$regex .= "(':[0-9]{2,5})?";//Port
$regex .= "('/([a-z0-9+'$_-]'.?)+)*'/?";//Path
$regex .= "('?[a-z+&'$_.-][a-z0-9;:@&%=+'/'$_.-]*)?";//GET Query
$regex .= "(#[a-z_.-][a-z0-9+'$_.-]*)?";//Anchor
return str_replace
(
    array('href="','http://http://','http://https://','http:///'),
    array('href="http://','http://','https://','/'),
    preg_replace('/'.$regex.'/i','<a href="'0" target="_blank" class="lgray">'0</a>',$message)
);

在修改中，我使http或www成为必需的，删除了一些不必要的检查，并将域扩展名从3个字符扩展到4个字符（.info也是一个域）。

免责声明：这些是非常基本的，不会考虑检查有效的TLD或文件扩展名。使用风险自负。

假设您不需要考虑目录或文件，要仅匹配那些没有子域的基本 URL，您可以使用以下正则表达式：

(?<=^|['n's])(?:https?:'/'/)?(?:www'.)?[a-zA-Z0-9-.]+'.com'/?(?=$|['n's])

#DESCRIPTION::
#  (?<=^|['n's])           Checks to see that what's preceding the URL is the beginning of the string, or a newline, or whitespace.
#  (?:https?:'/'/)?        Matches http(s) if it is there
#  (?:www'.)?              Matches www. if it is there
#  [a-zA-Z0-9-]+           Matches "example" in "example.com" (as well as any other valid URL character; will also match subdomains)
#  '.com'/?                Matches .com(/)
#  (?=$|['n's])            Checks to see that what's following the URL is the end of the string, or a newline, or whitespace.

如果你还需要匹配目录和文件，则需要稍微修改正则表达式的末尾并添加：

(?<=^|['n's])(?:https?:'/'/)?(?:www'.)?[a-zA-Z0-9-.]+'.com(?:(?:'/['w]+)+)?(?:'/|'.['w]+)?(?=$|['n's])

#DESCRIPTION::
#  (?<=^|['n's])           Checks to see that what's preceding the URL is the beginning of the string, or a newline, or whitespace.
#  (?:https?:'/'/)?        Matches http(s) if it is there
#  (?:www'.)?              Matches www. if it is there
#  [a-zA-Z0-9-.]+          Matches "example" in "example.com" (as well as any other valid URL character; will also match subdomains)
#  '.com                   Matches .com
#  (?:                     Start of a group
#     (?:'/['w]+)+         Attempts to find subdirectories by matching /, then word characters
#  )?                      Ends the previous group. This group can be skipped, if there are no subdirectories
#  (?:'/|'.['w]+)?         Matches a file extension if it is there, or a / if it is there.
#  (?=$|['n's])            Checks to see that what's following the URL is the end of the string, or a newline, or whitespace.

试试这个：

$pattern = preg_replace("/((https:'/'/|http:'/'/||http:'/'/www.|https:'/'/www.|www.)+(['w'/])+(.com'/|.com))/i","<a target='"_blank'" href='"$1'">$1</a>",$url);