Opendir():- It opens the directory. This function returns a directory stream on success and FALSE and an error on failure.
Context is a set of options that can modify the behavior of a stream
Example: opens sample directory.
$dir = opendir("directory");
Readdir(): It returns an entry from a directory handle opened by opendir().
$file = readdir($dir);
closedir(): It closes a directory handle opened by opendir().
$file = close($dir);