-a     Behave as though all of the options -mnrsv were specified.

-m     Write the name of the hardware type on which the system is running to standard output.

-n     Write the name of this node within an implementation-defined communications network.

-r     Write the current release level of the operating system implementation.

-s     Write the name of the implementation of the operating system.

-v     Write the current version level of this release of the operating system implementation.