What are the potential pitfalls of manually parsing path strings in PHP when trying to remove the last directory?

When manually parsing path strings in PHP to remove the last directory, potential pitfalls include not accounting for different directory separators on different operating systems, not handling edge cases like paths ending with a trailing slash, and not considering special characters in directory names. To solve this, you can use built-in PHP functions like `dirname()` to safely remove the last directory from a path string.

$path = "/path/to/directory/";
$parentDirectory = rtrim(dirname($path), DIRECTORY_SEPARATOR);
echo $parentDirectory;