Quercus: POSIX
From Resin 3.0
A few of the functions in The PHP POSIX package simply cannot be implemented without the use of JNI. Currently Quercus does not implement such functions. This is partly for security reasons.
If you desperately need functions from this package, we suggest wrapping a com.caucho.quercus.env.JavaValue around the Jtux library, which provides a function-and-argument-exact replica of the POSIX APIs (except for error handling, which is done by exceptions).