This is an example to check if a folder exists and if not exist, build this folder:
//produce the string according to the date and the format is like this： 201010
$subfolder = gmdate(“Ym”, time());

//file_exists() check if the folder or a file exists; if it exists, reture true, otherwise false.
// dirname(__FILE__) returns the current folder path.
$dir = dirname(__FILE__) . $subfolder;
if (file_exists($dir)) {
echo “this folder” . $dir . “exits”;
} else {
mkdir($dir,0777);
}
?>

An example to check if a file exists under the folder:
$dir = dirname(__FILE__) . “\\201010”;
$file = $dir . “\\data.txt”;

if (file_exists($file)) {
echo “In the folder: ” . $dir . “, the file ” . $file . “exits”;
} else {
echo “In the folder” . $dir . “,” . $file . “doesn’t exist”;
}
?>

I found that the folders that are created by the script above on the web hosting space and the files in them can’t be deleted through the interface provided by cPanel.