This module contains an interface to those functions defined in
the IEEE 1003.1 (POSIX.1) standards document which are not
accessible through other means. POSIX.1 for example defined the
open(), read(), write() and close() functions, too, which
traditionally have been part of PHP 3 for a long time. Some more
system specific functions have not been available before, though,
and this module tries to remedy this by providing easy access to
Sensitive data can be retrieved with the POSIX functions, e.g.
posix_getpwnam() and friends. None of the
POSIX function perform any kind of access
checking when safe mode is enabled.
It's therefore strongly advised to
disable the POSIX extension at all (use
--disable-posix in your configure line) if you're
operating in such an environment.