cat job1.out
line1

cat restart_job1.job 
01234567890123456789

cat chk_job.ksh 
#!/bin/ksh

#
# Define variables.
#
# These values can be passed in
# or you can determine them with 
# logic.  It all depends on how 
# you're calling this script.
#
# For this test we'll just set them
# locally in the script.
#
JOB_STEP=9

#
# Assuming your job logs and restart files
# are using standard naming conventions:
#
#    ie:  job log file:  job1.out
#         restart file:  restart_job1.job
#
JOB_LOG=job1.out
RESTART_FILE=restart_$(echo "${JOB_LOG}" | cut -d\. -f1).job
RESTART_LINE=$(cat ${RESTART_FILE})

#
# Count the number of lines containing
# an Oracle error.
#
ORA_ERROR_COUNT=$(grep "ORA-" job1.out | wc -l)

if [ "${ORA_ERROR_COUNT}" -gt 0 ]; then
   echo "ERROR FOUND"

   #
   # You can change restart_job1.job file
   # at this point.
   #
   echo "${RESTART_LINE}" | sed "s/^0/${JOB_STEP}/" > ${RESTART_FILE}

else
   echo "JOB COMPLETED SUCCESSFULLY"
fi

exit 0

./chk_job.ksh
JOB COMPLETED SUCCESSFULLY

cat restart_job1.job 
01234567890123456789

cat job1.out
ORA- line1

./chk_job.ksh 
ERROR FOUND

cat restart_job1.job 
91234567890123456789