Capturing trace data through environment variables

The values for HWTH_OPT_VERBOSE, HWTH_OPT_VERBOSE_OUTPUT and HWTH_OPT_SSLTRACE connection handle options can be altered at runtime using environment variables with corresponding names. The value of the runtime environment variable, if valid, will take precedence over any value specified for that option using the HWTHSET service. A valid value for the integer option HWTH_OPT_VERBOSE is a string that matches the name of the value.

Override values that are not valid are ignored, and should not cause new errors. Specifically, any override that would cause its corresponding HWTHSET to fail is ignored, and any original application settings are preserved. An overridden DD name for HWTH_OPT_VERBOSE_OUTPUT that is not found at run time is ignored. An overridden path name for HWTH_OPT_SSLTRACE is always passed to SystemSSL unchanged. SystemSSL tolerates bad values but specifying bad paths may signal access violations.

For example, if a REXX application sets verbose to off using HWTHSET:

address hwthttp  hwthset ReturnCode SessionHandle HWTH_OPT_VERBOSE HWTH_VERBOSE_OFF DiagArea

The user executing the application, can set the HWTH_OPT_VERBOSE environment variable to HWTH_VERBOSE_ON to override the application setting and enable tracing.