I produced an application that is have to run in linux began by crontab. A mistake happened if this attempted for connecting oracle database: it came back
SQLO_INVALID_DB_HANDLE. But when began it by hand things are okay.
I wager you will find no path-related mistakes here, because everything goes well except the bond towards the Oracle database. Oracle8 functions are utilized during my code.
Oracle uses a few atmosphere variables, like ORACLE_HOME, TNS_HOME, ORACLE_SID. They could be missing out of your crontab atmosphere.