Check whether a Directory Exists in PHP

问题:

I know, I know, this sounds soo easy. But I can't seem to find the correct answer on the Internet.

One of the solution I found was to use is_dir.

if(is_dir($dir))
  echo 'directory exists';
else
  echo 'drectory not exist';

But this is wrong-- All this function does is to check whether the $dir is a directory, it doesn't check whether the directory exists, or not. In other words if I put:

$rootDir = "C:\\Documents and Settings\\test\\My Documents\\Image Directory\\Me Dog\\";

then the function will return a true, even though you can find no such directory on your web server.

Any ideas?

回答1:

Should work correctly. From is_dir() documentation:

Returns TRUE if the filename exists and is a directory, FALSE otherwise.

Well, anyway if it doesn't try this:

if(file_exists($dir) && is_dir($dir))

BTW. results of these functions are cached in stat cache. Use clearstatcache() to clean that cache.

回答2:

You'll probably want to use opendir() after is_dir() agrees that the path (could) be a directory.

If the resource returned by opendir() is valid, you know you have a directory, and already have a handle to read it.

Just be sure to call closedir(), either way, if a valid handle is returned.

Edit:

This answer assumes that you'll be opening the directory either way. If you just need to ensure a path is sane / valid, file_exists() is much cheaper.

回答3:

You could try this:

if(is_dir($dir) && is_writeable($dir))
{
    // ...
}

回答4:

bool file_exists ( string $filename )

Checks whether a file or directory exists.

http://php.net/manual/en/function.file-exists.php