Can I make system calls from Iris Fortran?

[Steve Gaarder]

I am writing a program in Fortran on a 3020 that needs to do some Unix
calls to read and change directories.  The usual set of Fortran library 
routines for the purpose are totally absent from the manual. 
Do they really not exist, or are they just
not documented?  Even AT&T("all you get is system V") provides the Fortran
routines!  Is there a reasonably portable way to make system calls directly
from Fortran?
-- 
Steve Gaarder                                         
Cornell University, 171 Hollister, Ithaca NY 14853           607-255-5389
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