(PHP 4, PHP 5, PHP 7)
opendir — Open directory handle
$path
   [, resource $context
  ] )Opens up a directory handle to be used in subsequent closedir(), readdir(), and rewinddir() calls.
pathThe directory path that is to be opened
context
       For a description of the context parameter, 
       refer to the streams section of
       the manual.
      
   Returns a directory handle resource on success, or
   FALSE on failure.
  
   If path is not a valid directory or the
   directory can not be opened due to permission restrictions or
   filesystem errors, opendir() returns FALSE and
   generates a PHP error of level 
   E_WARNING.  You can suppress the error output of
   opendir() by prepending
   '@' to the
   front of the function name.
  
| Version | Description | 
|---|---|
| 5.0.0 | pathsupports the ftp:// 
        URL wrapper. | 
| 4.3.0 | pathcan also be any URL which supports 
        directory listing, however only the file://
        URL wrapper supports this in PHP 4 | 
Example #1 opendir() example
<?php
$dir = "/etc/php5/";
// Open a known directory, and proceed to read its contents
if (is_dir($dir)) {
    if ($dh = opendir($dir)) {
        while (($file = readdir($dh)) !== false) {
            echo "filename: $file : filetype: " . filetype($dir . $file) . "\n";
        }
        closedir($dh);
    }
}
?>
The above example will output something similar to:
filename: . : filetype: dir filename: .. : filetype: dir filename: apache : filetype: dir filename: cgi : filetype: dir filename: cli : filetype: dir