^start of line
.*?any character (except for line terminators), repeated any number of times
_the literal _ (9510 / 1378 / 5F16)
\Kresets the starting point of the reported match. Any previously consumed characters are no longer included in the final match
Negated Character Class[^.]* *matches any number of characters outside the set below:
.the literal . (4610 / 568 / 2E16)
Positive Lookahead(?=\.\S+$) \.the literal . (4610 / 568 / 2E16)
\S+any non-whitespace character, repeated at least once
$end of line
g modifier: global. Finds all matches instead of stopping after the first
m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string