Integration in a DSS

[Vida Jakabhazy]

! Date: Wed, 9 Aug 95 08:43:57 CDT
! From: Mike Bender <mike at ce.UManitoba.CA>
! Subject: Integration in a DSS
! 
! I have been using Grass 4.1 on its own, using command line codes.  I go
! through the normal prompting upon typing 'grass4.1 <Enter>' such as
! database and mapset.  ...
! 
! My question is how to start grass up without the interactive prompting
! for database and mapset? 

A smart man introduced me to the unix program 'expect' (Tcl based) which 
might suit your needs, at least to some degree.  The blurb from the man
page reads:

    "Expect is a program that "talks" to other  interactive  pro-
     grams  according  to a script.  Following the script, Expect
     knows what can be expected  from  a  program  and  what  the
     correct  response  should  be.  An interpreted language pro-
     vides branching and high-level control structures to  direct
     the  dialogue.   In  addition, the user can take control and
     interact directly when desired, afterward returning  control
     to the script."
 
Below is a bit of script that uses expect commands to run r.support
providing grass with answers to all the prompts:

        #!/opt/bin/expect
         
        spawn /opt/grass/source/sun4/bin/r.support
        expect "*>*"
        send "$filename\n"
        expect {*[n]*}
        send "n\n"
        expect {*[n]*}
        send "y\n"
        expect {*[n]*}
        send "n\n"
        expect {*[n]*}
        send "y\n"
        expect {*>*}
        send "4\n"
        expect {*-->*}
        send "\n"
        expect {*[n]*}
        send "n\n"


I don't know where our copy came from, but I'm certain you can find it
from some anonymous ftp source.  Hope this gives you some ideas.

Vida Jakabhazy
vida at aer.com