Posix is a PHP extension rather than part of PHP core. WordPress tries to minimize use of extensions as much as possible in its core. In specific case of Posix one — it has very notable flaw of not being available on Windows platform altogether.
Posix is a PHP extension rather than part of PHP core. WordPress tries to minimize use of extensions as much as possible in its core. In specific case of Posix one — it has very notable flaw of not being available on Windows platform altogether.