Regular expression to match line that doesn't contain a word?
stackoverflow.com
stackoverflow.com
I believe regexes are a triumph of declarative (and therefore, functional) programming: tell the computer what results you want, without describing the control flow. Even though sometimes they are not the right tool for the job, the paradigm shift from declarative to imperative is often appealing enough to invite their use.
if {[string match "* hede *" $line] == 0} { Yay! }
OR
foreach line $lineData { if {$line == "hede"} { continue } }