使用PHP检查文件是否在远程服务器上

Question

I'm basically looking for an if statement:

if (....) { }

else { }

...that will check if the current file is on a remote server (online, on my website, rather than in my local configuration with Xampp or Mamp).

I've done some research already, and it brought me to file_exists , but I'm not sure if this is what I want or if there's a better way to do this.

I'm not sure if it's relevant why I'm doing this, but here goes: I have a couple different configurations in a functions.php page, and I want it to act differently when it's in production, and when it's in test-mode locally.

Answer 1

There are a few conditions that have been left out of your question, such as whether the file is even callable via an HTTP request, and whether you are concerned with if the file is the same on the remote server. If all you care about it existence of the file, and it is exposed via HTTP, you can make an HTTP request for the file, and check the response code. You may want to put a little handling logic in the file to handle these requests. If the file isn't accessible via an HTTP request, there are a couple of more options:

1) Create a script just to check for the file. This will take some extra work to make it secure. 2) FTP into the server and try to download the file.

With either solution, if you desire to know if the file is the same in both places, you can use an MD5 hash on both ends to find out.

Answer 2

如果文件将位于其他主机上，则可以使用gethostbyaddr检查，并将其与您的localhost或服务器匹配，然后再跟相应的操作语句进行匹配。

Answer 3

You could use filectime that returns FALSE if the file is remote.

$remote = empty(@filectime($url));
if ($remote) {
  // File is remote.
}
else {
  // File is local.
}