code: def find_gromacs_command(commands):
      
  
      # We could try executing 'name' or 'driver name' but to keep things lean we
      # just check if the executables can be found and then hope for the best.
  
      commands = utilities.asiterable(commands)
      for command in commands:
          try:
              driver, name = command.split()
          except ValueError:
              driver, name = None, command
  
          executable = driver if driver else name
          if utilities.which(executable):
              break
      else:
          raise OSError(errno.ENOENT, "No Gromacs executable found in", ", ".join(commands))
  
      return driver, name
docs: Return *driver* and *name* of the first command that can be found on :envvar:`PATH`