os/posix-exec

    cfunction
    src/core/os.c on line 1421, column 1

    (os/posix-exec args &opt flags env)

    Use the execvpe or execve system calls to replace the current 
    process with an interface similar to os/execute. However, instead 
    of creating a subprocess, the current process is replaced. Is not 
    supported on Windows, and does not allow redirection of stdio.