Joined: 06 Jun 2008 Posts: 8518 Location: Dubuque, Iowa, USA
What you want to do would be easy in CICS. However, since you're using "online", CICS may not be relevant to your needs.
The best answers on this, or any forum, come when the question thoroughly explains the environment, the perceived problem, and what has been tried already. It helps when the question uses standard terminology (mainframes have files in Unix System Services and on tapes -- period; all disk data is stored in data sets, not files).