I analyzed this and am not going to support it for now. It is complex to implement and the risk is high that it is used incorrectly. The bash installations I've tested have it off by default and only on using the shopt command. Some versions dont support it at all (cygwin). It is not part of the standard sh/ksh syntax either.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
I analyzed this and am not going to support it for now. It is complex to implement and the risk is high that it is used incorrectly. The bash installations I've tested have it off by default and only on using the shopt command. Some versions dont support it at all (cygwin). It is not part of the standard sh/ksh syntax either.