How to parse data from the filename w/o its extension.

Problem: If PEOB is included in the part of a filename that is supplied as input parameter, do one thing
ELSE
do another thing.

Shel Script Example
==================

#!/bin/ksh
#$1 is a input parameter filename w/o the extension

SHLIB_PATH=$SHLIB_PATH:/opt/g1/doc1

cd /opt/g1/doc1/doc1bodi

if [ filename has 'PEOB' ]; then
echo "EOB"
/opt/g1/doc1/doc1gen "EOB.hip" ops=test-hp.ops input-data="$1"
else
echo "REGULAR"
/opt/g1/doc1/doc1gen "OK.hip" ops=test-hp.ops input-data="$1"
fi

es=$?
if [ $es != 0 ]; then
return $es
fi