Question

Is it possible to use something equivalent to a NOT operation in a regular expression so as to match the string only if it does NOT contain a certain character in a given position?

I see the meta characters say ^ can mean “negate a class” but I am having trouble finding examples of its use. And that particular character is ambiguous with the start of a string so its a bit confusing as well.

Answer 1

 'foo[^b]ar'

Will match anything starts with foo and ends with ar but foobar. So it negates the [^b] class, which can be a list of characters too (and using ranges is accepted like: [^b-d] which skips b, c, d).