You normally configure your run-time system using a project's properties in the IDE. However, some run-time behavior cannot be configured using the IDE; this must be configured using run-time tunables, which are stored in a run-time configuration file.
When your run-time system or linked executable starts up, it attempts to read the run-time configuration file. The run-time configuration file specifies values for the run-time tunables.
If a setting specified in the IDE conflicts with a setting in the configuration file, the setting specified in the IDE takes precedence.
The run-time configuration file is shared by all users of the run-time system.
For native COBOL, you create or edit a text-based run-time configuration file with a text editor, and then specify the location and name of the run-time configuration file using the COBCONFIG environment variable, or if you are developing a COBOL JVM project and need to specify Java property files, the COBCONFIGJVM environment variable. The format of the text file is described in the sections Format of a Configuration File for Native COBOL and List of Run-time Tunables.
For example, if you want to use a configuration file called myconf.cfg , you set COBCONFIG as follows.
set COBCONFIG=e:\mydir\myconf.cfg
If you want to use a Java property file called myconf.properties for a JVM project, you set COBCONFIGJVM as follows.
set COBCONFIGJVM=e:\mydir\myconf.properties
For .NET COBOL, you add a configuration file (such as an application.configuration file or web.configuration file) in Visual Studio. There is no need to use an environment variable to specify its location, because the file is part of the application managed at run-time.
The use of a configuration file is optional - no error is issued if it does not exist.