^start of string
Non-Capturing Group(?:https?:\/\/)? ?repeats the group contents below at most once:
httpthe literal text http (case sensitive) s?optionally matches the literal s (11510 / 1638 / 7316) (case sensitive)
:the literal : (5810 / 728 / 3A16)
\/the literal / (4710 / 578 / 2F16)
\/the literal / (4710 / 578 / 2F16)
+matches at least one character from the set below:
\wany word character
.the literal . (4610 / 568 / 2E16)
-the literal - (4510 / 558 / 2D16)
\.the literal . (4610 / 568 / 2E16)
Negative Lookahead(?!local) localthe literal text local (case sensitive) \w+any word character, repeated at least once
\/the literal / (4710 / 578 / 2F16)
.*any character (except for line terminators), repeated any number of times
$end of string, or before its final line terminator