grep pO *pf >z
grep PO *pf >>z
grep po *pf >>z
grep Po *pf >>z
grep sO *pf >>z
grep SO *pf >>z
grep so *pf >>z
grep So *pf >>z
 
grep "p " *pf > zz 
grep "P " *pf >> zz
grep "s " *pf >> zz
grep "S " *pf >> zz
 
grep "?" *pf >q
 
grep "? ?" q >qq
grep "-" *pf >>qq
 
echo "check the 4 files z, zz, q, qq"