( void )
When you use stat(), lstat(), or
any of the other functions listed in the affected functions list (below),
PHP caches the information those functions return in order to provide
faster performance. However, in certain cases, you may want to clear the
cached information. For instance, if the same file is being checked
multiple times within a single script, and that file is in danger of
being removed or changed during that script's operation, you may elect to
clear the status cache. In these cases, you can use the
clearstatcache() function to clear the information
that PHP caches about a file.
You should also note that PHP doesn't cache information about non-existent
files. So, if you call file_exists() on a file that
doesn't exist, it will return FALSE until you create the file. If you
create the file, it will return TRUE even if you then delete the file.
This function caches information about specific filenames, so you only
need to call clearstatcache() if you are performing
multiple operations on the same filename and require the information
about that particular file to not be cached.
Affected functions include stat(),