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
     these functions.
    
| Warning | 
| 
      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.
      | 
Note: This extension is not
available on Windows platforms.