Opatch fails when i use a script to apply a patch

HI:

My script like this

su - grid <<!

expect <<eof

spawn /opt/app/11.2.0/grid/OPatch/opatch apply /opt/app/psu8/28813878/28729234 -oh /opt/app/11.2.0/grid -local -ocmrf /opt/app/11.2.0/grid/OPatch/ocm.rsp

expect {

"Is the local system ready for patching?" {send "y\r";exp_continue}

}

eof

!

=========================================================================

The response is these:

spawn /opt/app/11.2.0/grid/OPatch/opatch apply /opt/app/psu8/28813878/28729234 -oh /opt/app/11.2.0/grid -local -ocmrf /opt/app/11.2.0/grid/OPatch/ocm.rsp

Oracle Interim Patch Installer version 11.2.0.3.6

Copyright (c) 2013, Oracle Corporation. All rights reserved.

Oracle Home : /opt/app/11.2.0/grid

Central Inventory : /opt/app/oraInventory

from : /opt/app/11.2.0/grid/oraInst.loc