ClassAd “Meta-Operators”
Meta operators allow you to compare against “UNDEFINED” as if it were a real value:
- =?= is “meta-equal-to”
- =!= is “meta-not-equal-to”
- Color != “Red” (non-meta) would evaluate to UNDEFINED if Color is not defined
- Color =!= “Red” would evaluate to True if Color is not defined, since UNDEFINED is not “Red”