specify posix.sys.utsname:

- before:

    utsname = require "posix.sys.utsname"

- describe uname:

  - before:

      uname = utsname.uname

      u = uname ()

  - context with bad arguments:

      badargs.diagnose (uname, "()")

  - it returns a PosixUtsname:

      expect (prototype (u)).to_be "PosixUtsname"

  - it returns machine name:

      expect (u.machine).to_be (cmd_output "uname -m")

  - it returns nodename:

      expect (u.nodename).to_be (cmd_output "uname -n")

  - it returns operating system release:

      expect (u.release).to_be (cmd_output "uname -r")

  - it returns system name:

      expect (u.sysname).to_be (cmd_output "uname -s")

  - it returns operating system version:

      expect (u.version).to_be (cmd_output "uname -v")