Include selection expression value in gridmanager log filename
When using GRIDMANAGER_SELECTION_EXPR to launch multiple gridmanger daemons per user, it'd be nice to have each gridmanager write to its own log file. This simplifies looking at the logs of just one gridmanager instance.
The evaluated selection expression value will be automatically appended to the gridmanager’s log filename, if GRIDMANAGER_LOG_APPEND_SELECTION_EXPR is True in the config file. The default is False.
This is a feature request from CMS.
CODE REVIEW code looks good. documentation looks good.
A minor thing - the check && *attr_value for the empty string is not needed here, because the code above guarantees that the string will be NULL or non-empty.