Php 仅当不存在目录时，才删除URL中的最后一个斜杠

我正在尝试从URL中删除最后一个

/

，但只有在没有目录的情况下。是否有办法检查

是否（仅3个斜杠和非https）删除斜杠
？还是有更好的方法来完成我想做的事情

到目前为止我所拥有的
$url=preg_replace（数组（'{http://}'，'{/$}'），''.$project->url）；

当前输出：

http://www.example.org/          =>www.example.org
https://www.example.org/         => https://www.example.org
http://www.example.org/dir/      =>www.example.org/dir
https://www.example.org/dir/     => https://www.example.org/dir
http://www.example.org/dir/dir/  =>www.example.org/dir/dir
https://www.example.org/dir/dir/ => https://www.example.org/dir/dir

我想要什么
http://www.example.org/          =>www.example.org
https://www.example.org/         => https://www.example.org
http://www.example.org/dir/      =>www.example.org/dir/
https://www.example.org/dir/     => https://www.example.org/dir/
http://www.example.org/dir/dir/  =>www.example.org/dir/dir/
https://www.example.org/dir/dir/ => https://www.example.org/dir/dir/
这可能不是最好的方法，但可以完成以下任务：

$num_slash = substr_count($url, '/');
if ($num_slash > 3)
{
    // i have directory
    if (strpos($url, ':') == 4)
        $url = substr($url, 7);
    // this will take care of 
    // http://www.example.org/dir/dir/ => www.example.org/dir/dir/
}
else
{
    $url = preg_replace(array('{http://}', '{/$}'), '', $project->url);
    // this will take care of as you already mentioned
    // http://www.example.org/  => www.example.org
    // https://www.example.org/ => https://www.example.org
}
// so whenever you have https, nothing will happen to your url

您可以尝试以下方法：

$url = preg_replace('~^(?:(https://)|http://)?+([^/]++)(?:(/[^\s"']++)|/)?+~', '$1$2$3', $url);

或者更简单（如果
$url
仅包含url）

请注意，对于这些模式：

www.example.org/
give
www.example.org

及

http://www.example.org
give
www.example.org

第二个图案细节

~                         # pattern delimiter
^                         # anchor for the begining of the string
(?:(https://)|http://)?+  # optional "http(s)://" , but only "https://" 
                          # is captured in group $1 (not "http://") 
([^/]++)                  # capturing group $2: all characters except "/"
(?:(/.++)|/)?+            # a slash followed by characters (capturing group $3)
                          # or only a slash (not captured),
                          # all this part is optional "?+"
~                         # pattern delimiter

在离开或删除斜杠之前，您必须先检查是否有目录。谢谢。我用了第二个。你有没有可能再多解释一点，让我了解它在做什么，看看那里的操作顺序？谢谢
~                         # pattern delimiter
^                         # anchor for the begining of the string
(?:(https://)|http://)?+  # optional "http(s)://" , but only "https://" 
                          # is captured in group $1 (not "http://") 
([^/]++)                  # capturing group $2: all characters except "/"
(?:(/.++)|/)?+            # a slash followed by characters (capturing group $3)
                          # or only a slash (not captured),
                          # all this part is optional "?+"
~                         # pattern delimiter