From the Interesting Tidbits Dept. Here’s probably the shortest RESguru posting to date, but it’s been a little thing that has been itching to be posted for a while. In all it’s simplicity it’s about how you would reference an empty string in either Automation Manager or Workspace Manager. Since there isn’t a NULL operator per say, we have to rely on our old friend, Mr. PatternMatching. In other words for the uninitiated, RES products supports a pletora of wildcard operators within the text input fields of the products. You can also use variables and functions here. Also check out the RESpedia entry on patternmaching.
The use-cases are many, as you might need to check on environment variables, registry settings, AD properties, file versions or something completely different. Here is a quite simple one: Let’s say we want to check if a variable is set or not. All we have to do is use the pattern “?*” without the quotation marks. The questionmark determines that a single any-character must be present, and the asterisk says that any number of characters including none, may follow. Here on the right is a screenshot which illustrates the usage. PS: Thanks to Dave Bryant for sharing this nugget.