Serialize data, if needed.

Unserialize data only if it was serialized.

Set the mbstring internal encoding to a binary safe encoding when func_overload is enabled.

Convert given MySQL date string into a different format.

Parses and formats a MySQL datetime (Y-m-d H:i:s) for ISO8601 (Y-m-d\TH:i:s).

Set the headers to prevent caching for the different browsers.

Convert float number to format based on the locale.

Test if a given filesystem path is absolute.

Join two filesystem paths together.

Get the size of a directory recursively.