The idea behind Be's POSIX support is to make it easier rather than harder to port (compile and run) POSIX-style code that you may have lying around. To that end, we have a library which contains most of the "popular" POSIX calls.
Most Unix code compiles with little or no change, e.g., all of the 100+
GNU utilities included with the BeOS distribution compiled with no
changes. Even more difficult programs, such as the GNU Bash shell, work.