file_the literal text file_ (case insensitive) \d+a digit, repeated at least once
_the literal _ (9510 / 1378 / 5F16)
\S*any non-whitespace character, repeated any number of times
_sthe literal text _s (case insensitive) \.the literal . (4610 / 568 / 2E16)
txtthe literal text txt (case insensitive) g modifier: global. Finds all matches instead of stopping after the first
i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters